We have analyzed photoelectron jet formation in strong-field ionization using the hydrodynamic picture of quantum mechanics. We showed that von-Kármán-like vortex streets emerge in between jets in ...photoelectron momentum distributions. The spatial orientation of the jets can be controlled by tailoring the carrier-envelope phase of the driving laser pulse. This indicates that it is possible to experimentally measure emitted photoelectrons off the optical axis, which opens up new possibilities for high-frequency laser pulse diagnostics.
Aim
Ligation of the intersphincteric fistula tract (LIFT) has been proposed as a treatment of trans‐sphincteric fistula in perianal Crohn's disease (CD). The aim of this study was to look at our ...experience of the LIFT procedure in CD patients on long‐term follow‐up. Specifically, we aimed to determine the fistula healing rate after the LIFT procedure after more than 12 months follow‐up and to identify any prognostic factors.
Method
Retrospective study of patients with trans‐sphincteric Crohn's fistula tracts treated with the LIFT procedure between January 2011 and October 2015. Complete fistula healing as well as clinical outcomes were analysed.
Results
Data were available for 23 patients. After a median follow‐up of 23 months, LIFT site healing was 48%. Patients with healed LIFT had a median follow‐up time of 10.5 months, while patients with failed LIFT had a median follow‐up time of 31 months (P = 0.04). Median time to failure was 9 months for patients with follow‐up > 1 year. Most patients failed within 1 year (9/12; 75%) of the procedure. In multi‐site CD, the LIFT procedure was more likely to be successful in those with small bowel disease (P = 0.04) compared with colonic disease (P = 0.02). Other factors such as preoperative use of biological therapies, presence of a seton, previous repair attempts, fistula position, type or number of fistulas, multiple fistula tracts, smoking status and other associated perianal disease did not appear to influence LIFT healing rates.
Conclusion
The LIFT procedure offers reasonable long‐term success in the treatment of perianal trans‐sphincteric fistulas associated with CD. LIFT is more likely to fail in patients with concurrent colonic CD than in patients with small bowel CD.
Aim
The origin of the amphitropic Mediterranean Basin and southern African disjunction (European–African amphitropical disjunction; EAAD) pattern is generally attributed to recent dispersal events. ...However, our knowledge is limited because the origin of the EAAD pattern has been almost exclusively studied in plants. Here, we investigate the origin of this wide‐ranging disjunction pattern in a group of wingless insects, consisting of two major clades, both of which have EAAD distributions.
Location
Sub‐Saharan Africa and Mediterranean region.
Taxon
Tribe Dendarini (Coleoptera: Tenebrionidae).
Methods
We reconstructed a dated molecular phylogeny of major lineages within Dendarini using maximum likelihood and Bayesian inference. The employed dataset included sequences of six genes (two mitochondrial and four nuclear fragments) generated for 72 species. To investigate the sequence and timing leading to present‐day wide‐ranging disjunction patterns, we conducted parametric historical biogeography analyses.
Results
The dated phylogenetic framework supports the monophyly of all major Dendarini lineages and highlights the origin of the tribe in sub‐Saharan Africa during the Middle Eocene. From there, representatives of the two major lineages colonized the Mediterranean region at the Oligocene‐Miocene boundary, with one lineage first reaching North Africa, whilst the other reached southern Europe.
Main conclusions
The origin of the EAAD in Dendarini beetles is ancient and better explained by the progressive fragmentation of the pan‐African rainforest that started in the Early Eocene than by other scenarios. This and the increased aridification associated with the global long‐term cooling trend that took place at that time had a strong influence on the diversification and distribution of xerophilic organisms such as dendarine beetles. This challenges the understanding of the origin of EAAD patterns, highlighting that they do not only result from recent dispersal events between the Pliocene and Pleistocene.
The Sauter-Schwinger process of electron-positron pair creation from the vacuum, driven by a sequence of time-dependent electric-field pulses, is studied in the framework of the quantum-field ...theoretical approach. As demonstrated by our numerical results, the momentum distributions of produced pairs exhibit intra- and interpulse interference structures. We show that such structures can be observed beyond the regime of applicability of the Wentzel-Kramers-Brillouin theory, which was the focus of earlier investigations. Going beyond these developments, we perform the analysis of the time-evolution operator for an arbitrary eigenmode of the fermionic field. This shows that a perfect coherent enhancement of the interpulse peaks can never be reached. A nearly perfect coherence, on the other hand, is due to nonadiabatic transitions at avoided crossings of the phases defining the unitary time evolution. This analysis allows us to determine the conditions under which the nearly perfect coherence is lost.
The taxonomic concept of the genus
Fåhraeus, 1870 is tested and revised based on newly identified material. The following new species are described:
,
,
, and
Kamiński.
Wilke, 1925 is considered as a ...junior subjective synonym of
Péringuey, 1899.
Péringuey, 1899 (=
Wilke, 1925) (transferred to
),
Fairmaire, 1897 (transferred to
), and
Wilke, 1925 (interpreted as
in Asidini) are excluded from
. An identification key for the species of the newly revised
is provided. The present paper brings the total number of species within the genus to six (
;
(Péringuey, 1899);
;
Fåhraeus, 1870;
;
Kamiński
). The morphology of female terminalia (ovipositor and genital tubes) is described for the genus for the first time.
A new generation of triazine-based coupling reagents (TBCRs), designed according to the concept of “superactive esters”, was obtained by treatment of ...4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium (DMTMM) chloride with lithium or silver tetrafluoroborate. The structure of 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium tetrafluoroborate was confirmed by X-ray diffraction. Activation of carboxylic acids by using this reagent proceeds via triazine “superactive ester”. The coupling reagent was successfully used for the synthesis of Z-, Boc-, and Fmoc-protected dipeptides derived from natural and unnatural sterically hindered amino acids and for fragment condensation, in 80−100% yield and with high enantiomeric purity. The manual SPPS of the ACP(65−74) peptide fragment (H-Val-Gln-Ala-Ala-Ile-Asp-Tyr-Ile-Asn-Gly-OH) proceeded significantly faster than with TBTU or HATU, as well as the automated SPPS of the same fragment gave a purer product than by using TBTU or PyBOP. The reagent was also demonstrated to be efficient in on-resin head-to-tail cyclization of constrained cyclopeptides, in SPPS synthesis of Aib peptides, and in the synthesis of esters from appropriate acids, alcohols, and phenols. The high efficiency and versatility of this new generation of TBCRs confirm, for the first time, the usefulness of the concept of “superactive esters” in rational design of the structure of coupling reagents.
Abstract
The first molecular phylogeny of the tribe Sepidiini is inferred from analyses of DNA sequence data from the following five loci (CAD, wg, COI, COII, 28S rRNA). Bayesian and maximum ...likelihood analyses were performed on a dataset containing 41 taxa, of which a majority represent Molurina (27) and Phanerotomeina (6). The resulting topologies were used to discuss phylogenetic placement and diagnostic characters of all of the genera representing Molurina. Within the subtribe, the results revealed paraphyly of the genus Psammodes. The P. vialis species-group, currently classified within Psammodes, was recovered as sister to all other Molurina genera. Based on this topology and morphological investigations, a new genus named Toktokkus gen. nov. is established. Within Phanerotomeina, Ocnodes is paraphyletic with regard to Tarsocnodes. In order to restore the monophyly of Ocnodes, the subgenus Chiliarchum stat. nov. is elevated to generic level. Finally, as the homology of female terminalia structures has never been fully assessed for Sepidiini, a comparative study of ovipositor morphology was conducted. As a result, this paper presents the first fully annotated ovipositors for tok-tokkie beetles.
The genus Anaxius Fåhraeus, 1870 (Tenebrionidae: Helopinina) is revised to include seven Southern African species, four of which are new. A taxonomic treatment of the genus is provided including a ...morphological study, new species descriptions, keys, illustrations, and notes on species distributions. The following species are treated: Anaxius bloubergensis sp. nov., A. campbellae Koch, 1958, A. limpopoensis sp. nov., A. meletsensis sp. nov., A. obesus Fåhraeus, 1870, A. prozeskyi Koch, 1958, and A. pseudoloensus sp. nov. A lectotype is designated for Anaxius obesus Fåhraeus, 1870 to fix the taxonomic status of this species. Anaxius montiscaerulei Koch, 1958 is considered as a synonym of A. campbellae.
Unlike aluminium oxide surface layers, magnesium oxide layers obtained by anodising processes exhibit some drawbacks, especially chemical instability in the presence of humidity, resulting in ...susceptibility to cracking and spalling. This work was dedicated to the development of a new hybrid method allowing us to produce composite aluminium oxide surface layers on magnesium alloys to ensure better performance properties than those achieved by magnesium oxide layers produced by commercial anodising. Composite aluminium oxide layers were produced on magnesium AZ91D alloy using a three stage hybrid method: magnetron sputtering deposition of an aluminium coating, followed by anodising in classical or plasma electrolytic oxidation (PEO) variant, combined with final tightening of the layer by hydrothermal treatment. The structure and the properties of the composite oxide layers were characterised. The investigations proved that the hybrid method using classical anodising is a promising method to improve the corrosion resistance of the AZ91D alloy much more efficiently than commercial anodising, but at the cost of decreased wear resistance. Based on preliminary investigation, a modified variant of the hybrid method using PEO treatment was found to result in both high wear and corrosion resistant composite aluminium oxide layers on AZ91D alloy, making it a prospective solution.
•Corrosion resistant composite Al oxide layers were produced on AZ91D Mg alloy.•a hybrid treatment was developed to produce composite Al oxide layers.•The hybrid treatment combines PVD, anodising or PEO with final sealing.•Only the composite Al oxide layers produced using PEO exhibit high wear resistance.•The composite layers obtained by PEO are an alternative for AZ91D alloy anodising.
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