XUV-beamline for photoelectron imaging spectroscopy with shaped pulses.

We introduce an extreme ultraviolet (XUV)-beamline designed for the time-resolved investigation and coherent control of attosecond (as) electron dynamics in atoms and molecules by polarization-shaped as-laser pulses. Shaped as-pulses are generated through high-harmonic generation (HHG) of tailored white-light supercontinua (WLS) in noble gases. The interaction of shaped as-pulses with the sample is studied using velocity map imaging (VMI) techniques to achieve the differential detection of photoelectron wave packets. The instrument consists of the WLS-beamline, which includes a hollow-core fiber compressor and a home-built 4f polarization pulse shaper, and the high-vacuum XUV-beamline, which combines an HHG-stage and a versatile multi-experiment vacuum chamber equipped with a home-built VMI spectrometer. The VMI spectrometer allows the detection of photoelectron wave packets from both the multiphoton ionization (MPI) of atomic or molecular samples by the tailored WLS-pulses and the single-photon ionization (SPI) by the shaped XUV-pulses. To characterize the VMI spectrometer, we studied the MPI of xenon atoms by linearly polarized WLS pulses. To validate the interplay of these components, we conducted experiments on the SPI of xenon atoms with linearly polarized XUV-pulses. Our results include the reconstruction of the 3D photoelectron momentum distribution (PMD) and initial findings on the coherent control of the PMD by tuning the spectrum of the XUV-pulses with the spectral phase of the WLS. Our results demonstrate the performance of the entire instrument for HHG-based photoelectron imaging spectroscopy with prototypical shaped pulses. Perspectively, we will employ polarization-tailored WLS-pulses to generate polarization-shaped as-pulses.

Deep-sea predator niche segregation revealed by combined cetacean biologging and eDNA analysis of cephalopod prey.

Fundamental insight on predator-prey dynamics in the deep sea is hampered by a lack of combined data on hunting behavior and prey spectra. Deep-sea niche segregation may evolve when predators target specific prey communities, but this hypothesis remains untested. We combined environmental DNA (eDNA) metabarcoding with biologging to assess cephalopod community composition in the deep-sea foraging habitat of two top predator cetaceans. Risso's dolphin and Cuvier's beaked whale selectively targeted distinct epi/meso- and bathypelagic foraging zones, holding eDNA of 39 cephalopod taxa, including 22 known prey. Contrary to expectation, extensive taxonomic overlap in prey spectra between foraging zones indicated that predator niche segregation was not driven by prey community composition alone. Instead, intraspecific prey spectrum differences may drive differentiation for hunting fewer, more calorific, mature cephalopods in deeper waters. The novel combination of methods presented here holds great promise to disclose elusive deep-sea predator-prey systems, aiding in their protection.

[Finger injuries with a focus on ligamentous structures]. / Verletzungen der Finger mit Fokus auf die Bandstrukturen.

BACKGROUND: Ligamentous lesions of the fingers are common everyday injuries and usually the result of distortion or overloading. Numerous examination methods are available for dedicated radiological diagnosis of sometimes complex injury patterns. OBJECTIVES: To review radiological diagnosis of the ligamentous structures of the finger joints including the presentation of anatomical, biomechanical and therapeutic aspects. MATERIALS AND METHODS: Presentation of the anatomy and biomechanics as well as the most common trauma mechanisms of the ligamentous structures. Review of the literature, discussion of recent work and diagnostic expert recommendations. RESULTS: The most relevant ligamentous structures are collateral ligaments, pulley ligaments, volar plates and tendons. The goal of radiologic diagnosis is to accurately define the injury pattern and to differentiate between simple and complicated ligamentous lesions. In unclear cases, magnetic resonance imaging (MRI) has become standard for further diagnostics, which may allow depiction of ligamentous structures in submillimetre resolution. CONCLUSIONS: Today, differential diagnosis includes all radiological modalities, which ensures the determination of an adequate therapy and prevention of sequel at a high standard.

N-terminal heterogeneity of parenchymal and vascular amyloid-ß deposits in Alzheimer's disease.

AIMS: The deposition of amyloid-ß (Aß) peptides in the form of extracellular plaques in the brain represents one of the classical hallmarks of Alzheimer's disease (AD). In addition to 'full-length' Aß starting with aspartic acid (Asp-1), considerable amounts of various shorter, N-terminally truncated Aß peptides have been identified by mass spectrometry in autopsy samples from individuals with AD. METHODS: Selectivity of several antibodies detecting full-length, total or N-terminally truncated Aß species has been characterized with capillary isoelectric focusing assays using a set of synthetic Aß peptides comprising different N-termini. We further assessed the N-terminal heterogeneity of extracellular and vascular Aß peptide deposits in the human brain by performing immunohistochemical analyses using sporadic AD cases with antibodies targeting different N-terminal residues, including the biosimilar antibodies Bapineuzumab and Crenezumab. RESULTS: While antibodies selectively recognizing Aß1-x showed a much weaker staining of extracellular plaques and tended to accentuate cerebrovascular amyloid deposits, antibodies detecting Aß starting with phenylalanine at position 4 of the Aß sequence showed abundant amyloid plaque immunoreactivity in the brain parenchyma. The biosimilar antibody Bapineuzumab recognized Aß starting at Asp-1 and demonstrated abundant immunoreactivity in AD brains. DISCUSSION: In contrast to other studied Aß1-x -specific antibodies, Bapineuzumab displayed stronger immunoreactivity on fixed tissue samples than with sodium dodecyl sulfate-denatured samples on Western blots. This suggests conformational preferences of this antibody. The diverse composition of plaques and vascular deposits stresses the importance of understanding the roles of various Aß variants during disease development and progression in order to generate appropriate target-developed therapies.

Foot and ankle service adaptation in response to COVID-19 and beyond.

The disruption to healthcare provision as a result of the COVID-19 pandemic has compelled us to streamline healthcare delivery. This has given us an opportunity to implement healthcare technology, reform inter-disciplinary collaboration and ultimately enhance patient care. We discuss some of the advances made by the foot and ankle department at our hospital. These innovations have broad applicability and will hopefully ignite discussion amoung a number of healthcare teams about improving the future care of their patients.

Transcriptome profiling reveals exposure to predicted end-of-century ocean acidification as a stealth stressor for Atlantic cod larvae.

Ocean acidification (OA), a direct consequence of increasing atmospheric CO2 concentration dissolving in ocean waters, is impacting many fish species. Little is known about the molecular mechanisms underlying the observed physiological impacts in fish. We used RNAseq to characterize the transcriptome of 3 different larval stages of Atlantic cod (Gadus morhua) exposed to simulated OA at levels (1179 µatm CO2) representing end-of-century predictions compared to controls (503 µatm CO2), which were shown to induce tissue damage and elevated mortality in G. morhua. Only few genes were differentially expressed in 6 and 13 days-post-hatching (dph) (3 and 16 genes, respectively), during a period when maximal mortality as a response to elevated pCO2 occurred. At 36 dph, 1413 genes were differentially expressed, most likely caused by developmental asynchrony between the treatment groups, with individuals under OA growing faster. A target gene analysis revealed only few genes of the universal and well-defined cellular stress response to be differentially expressed. We thus suggest that predicted ocean acidification levels constitute a "stealth stress" for early Atlantic cod larvae, with a rapid breakdown of cellular homeostasis leading to organismal death that was missed even with an 8-fold replication implemented in this study.

Odd electron wave packets from cycloidal ultrashort laser fields.

Polarization-tailored bichromatic femtosecond laser fields with cycloidal polarization profiles have emerged as a powerful tool for coherent control of quantum processes. We present an optical scheme to create and manipulate three-dimensional free electron wave packets with arbitrary rotational symmetry by combining advanced supercontinuum pulse shaping with high resolution photoelectron tomography. Here we use carrier-envelope phase-stable polarization-tailored bichromatic (3ω:4ω) counter- and corotating femtosecond laser pulses to generate 7-fold rotational symmetric and asymmetric photoelectron momentum distributions by multiphoton ionization of sodium atoms. To elucidate the physical mechanisms, we investigate the interplay between the symmetry properties of the driving field and the resulting electron wave packets by varying the optical field parameters. Our results show that the symmetry properties of electron wave packets are not fully determined by the field symmetry, but completely described by multipath quantum interference of states with different angular momenta.

Closed disruption of a single flexor digitorum superficialis tendon slip: 3 cases.

Two men and one woman (age 31, 36 and 45 years) felt a painful pop in the left middle, right middle and right index finger during sport-related activities (2 sport climbing and 1 judo). Clinical examination found a painful flexor tendon in zone 2 but no function deficit specific to the flexor digitorum superficialis (FDS) tendon. MRI and ultrasonography revealed a complete disruption of the radial FDS tendon slip only, which was found retracted between the A2 and A3 pulleys. All flexor tendon pulleys remained intact. Conservative and functional treatment resulted in unrestricted normal function and return to sport. Disruption of one FDS tendon slip is a differential diagnosis for a popping incident in the finger, which is typically associated with a closed flexor tendon pulley injury.

A simplified and sensitive immunoprecipitation mass spectrometry protocol for the analysis of amyloid-beta peptides in brain tissue.

In the field of Alzheimer's disease, there is an urgent need for novel analytical tools to identify disease-specific biomarkers and to evaluate therapeutics. Preclinical trials commonly employ amyloid beta (Aß) peptide signatures as a read-out. In this paper, we report a simplified and detailed protocol for robust immunoprecipitation of Aß in brain tissue prior to mass spectrometric detection exemplified by a study using transgenic mice. The established method employed murine monoclonal and rabbit polyclonal antibodies and was capable of yielding well-reproducible peaks of high intensity with low background signal intensities corresponding to various Aß forms.

An isolated cuboid dislocation. A case report.

INTRODUCTION: Isolated cuboid dislocations are rare injuries Jacobson (1990). It is clinically significant and important in surgical education, as it is an injury and a source of lateral foot pain that can be misdiagnosed at the time of initial presentation and may be difficult to identify clinically or with imaging Drummond and Hastings (1969). PRESENTATION OF CASE: We present a case report in a 33year old rugby player, who was injured during a match after a tackle. The patient had ongoing concerns that he was not recovering following initial discharge, as he was unable to weight bear since his initial presentation to the Emergency Department (E.D.), and he had ongoing lateral foot pain. DISCUSSION: Important clinical findings include lateral foot pain, a palpable gap at the cuboid level and difficulty weight-bearing. Closed reduction is usually difficult as it can be blocked mechanically by the extensor digitorum brevis muscle or peroneus longus tendon Dobbs et al. (1969). Initial X-Rays may be inconclusive with this presentation. CT scanning is indicated if suspicion for pathology is high. Open reduction and internal fixation with Kirschner wires are usually necessary for isolated cuboid dislocations. CONCLUSION: Our take home message from this case report is that cuboid dislocations are rare injuries and are important to be aware of in reviewing X-rays in the E.D. Particularly in patients with inversion and plantar flexion type injuries to their foot and ankle joint, with an inability to weight bear and lateral midfoot pain following their injury.

Iron Isotope Fractionation during Fe(II) Oxidation Mediated by the Oxygen-Producing Marine Cyanobacterium Synechococcus PCC 7002.

In this study, we couple iron isotope analysis to microscopic and mineralogical investigation of iron speciation during circumneutral Fe(II) oxidation and Fe(III) precipitation with photosynthetically produced oxygen. In the presence of the cyanobacterium Synechococcus PCC 7002, aqueous Fe(II) (Fe(II)aq) is oxidized and precipitated as amorphous Fe(III) oxyhydroxide minerals (iron precipitates, Feppt), with distinct isotopic fractionation (ε56Fe) values determined from fitting the δ56Fe(II)aq (1.79‰ and 2.15‰) and the δ56Feppt (2.44‰ and 2.98‰) data trends from two replicate experiments. Additional Fe(II) and Fe(III) phases were detected using microscopy and chemical extractions and likely represent Fe(II) and Fe(III) sorbed to minerals and cells. The iron desorbed with sodium acetate (FeNaAc) yielded heavier δ56Fe compositions than Fe(II)aq. Modeling of the fractionation during Fe(III) sorption to cells and Fe(II) sorption to Feppt, combined with equilibration of sorbed iron and with Fe(II)aq using published fractionation factors, is consistent with our resulting δ56FeNaAc. The δ56Feppt data trend is inconsistent with complete equilibrium exchange with Fe(II)aq. Because of this and our detection of microbially excreted organics (e.g., exopolysaccharides) coating Feppt in our microscopic analysis, we suggest that electron and atom exchange is partially suppressed in this system by biologically produced organics. These results indicate that cyanobacteria influence the fate and composition of iron in sunlit environments via their role in Fe(II) oxidation through O2 production, the capacity of their cell surfaces to sorb iron, and the interaction of secreted organics with Fe(III) minerals.

Electron Vortices in Femtosecond Multiphoton Ionization.

Multiphoton ionization of potassium atoms with a sequence of two counter-rotating circularly polarized femtosecond laser pulses produces vortex-shaped photoelectron momentum distributions in the polarization plane describing Archimedean spirals. The pulse sequences are produced by polarization shaping and the three-dimensional photoelectron distributions are tomographically reconstructed from velocity map imaging measurements. We show that perturbative ionization leads to electron vortices with c_{6} rotational symmetry. A change from c_{6} to c_{4} rotational symmetry of the vortices is demonstrated for nonperturbative interaction.

Genomes of coral dinoflagellate symbionts highlight evolutionary adaptations conducive to a symbiotic lifestyle.

Despite half a century of research, the biology of dinoflagellates remains enigmatic: they defy many functional and genetic traits attributed to typical eukaryotic cells. Genomic approaches to study dinoflagellates are often stymied due to their large, multi-gigabase genomes. Members of the genus Symbiodinium are photosynthetic endosymbionts of stony corals that provide the foundation of coral reef ecosystems. Their smaller genome sizes provide an opportunity to interrogate evolution and functionality of dinoflagellate genomes and endosymbiosis. We sequenced the genome of the ancestral Symbiodinium microadriaticum and compared it to the genomes of the more derived Symbiodinium minutum and Symbiodinium kawagutii and eukaryote model systems as well as transcriptomes from other dinoflagellates. Comparative analyses of genome and transcriptome protein sets show that all dinoflagellates, not only Symbiodinium, possess significantly more transmembrane transporters involved in the exchange of amino acids, lipids, and glycerol than other eukaryotes. Importantly, we find that only Symbiodinium harbor an extensive transporter repertoire associated with the provisioning of carbon and nitrogen. Analyses of these transporters show species-specific expansions, which provides a genomic basis to explain differential compatibilities to an array of hosts and environments, and highlights the putative importance of gene duplications as an evolutionary mechanism in dinoflagellates and Symbiodinium.

Simulated terrestrial runoff triggered a phytoplankton succession and changed seston stoichiometry in coastal lagoon mesocosms.

Climate change scenarios predict intensified terrestrial storm runoff, providing coastal ecosystems with large nutrient pulses and increased turbidity, with unknown consequences for the phytoplankton community. We conducted a 12-day mesocosm experiment in the Mediterranean Thau Lagoon (France), adding soil (simulated runoff) and fish (different food webs) in a 2 × 2 full factorial design and monitored phytoplankton composition, shade adaptation and stoichiometry. Diatoms (Chaetoceros) increased four-fold immediately after soil addition, prymnesiophytes and dinoflagellates peaked after six- and 12 days, respectively. Soil induced no phytoplankton shade adaptation. Fish reduced the positive soil effect on dinoflagellates (Scripsiella, Glenodinium), and diatom abundance in general. Phytoplankton community composition drove seston stoichiometry. In conclusion, pulsed terrestrial runoff can cause rapid, low quality (high carbon: nutrient) diatom blooms. However, bloom duration may be short and reduced in magnitude by fish. Thus, climate change may shift shallow coastal ecosystems towards famine or feast dynamics.

The extensor hallucis capsularis tendon--a prospective study of its occurrence and function.

BACKGROUND: There is inhomogeneous data about the hallucal extensor apparatus and the occurrence of accessory tendon slips and their function. We performed this study to clarify its anatomical features and make conclusions about its function. METHODS: Investigations were performed prospectively during operative correction of severe hallux valgus and interphalangeus in 60 consecutive cases. The occurrence, topographic location and size of accessory extensor tendons as well as the insertion patterns were recorded. After dissection traction of the accessory tendon was carried out to gain information about its function. RESULTS: In contradiction to previous studies reporting numerous variations in the distal attachments of the hallucal extensor apparatus with different accessory tendons described, our investigations showed constant anatomical features. In all but one case (98.3%) there was an accessory medial extensor hallucis longus tendon adjacent to the main tendon, always inserting on the dorsomedial aspect of the metatarsophalangeal joint capsule. We therefore chose the terminology extensor hallucis capsularis (EHC) used in previous studies. The intraoperative testing of the tendon showed it to exert a pretension of the metatarsophalangeal (MTP) joint capsule. CONCLUSION: Our study showed consistent anatomical features with an occurrence of the EHC tendon in 98.3%. We determined that its function is to pretension the MTP joint capsule, therefore avoiding capsular impingement during hallucal extension. The high incidence of the EHC tendon in our study may also postulate a correlation with MTP joint deformities and further cadaveric studies will be necessary to evaluate a possible predisposition for hallux valgus genesis.

[Splints in birth-related brachial plexus injuries]. / Zur Schienenbehandlung bei geburtstraumatischen Läsionen des Plexus brachialis.

Most cases of obstetrical brachial plexus palsies are mild traction injuries which resolve under physical therapy within several weeks or months. Severe ruptures or avulsion injuries of the plexus can lead to lifelong impairment of the upper extremities. Hence, in severe brachial plexus injuries the indications for brachial plexus reconstruction should be evaluated, early. At the age of about 3 months, the infant should be presented in a centre specialised in obstetrical brachial plexus palsies. In almost all cases intensive physical therapy is performed. In addition, many patients require splinting in order to gain function as part of the conservative therapy or for postoperative fixation. Depending on the type of splint, different demands are made on design, material and strategy of adjustment. Many different natural and synthetic materials are available for orthopaedic constructions. Because of its good adjustment options, the use of low temperature thermoplastic is steadily increasing. This contribution presents an overview of our currently used splints, new technical developments in our experience with more than 200 patients with obstetrical brachial plexus palsy. We present our experience with the most common splints for the use in fixation after birth-related brachial plexus surgery, subscapularis release, trapezius muscle transfer and functional improvement of hands with a lack of wrist extension.

Total Hip Arthroplasty in Mucopolysaccharidosis Type IH.

Children affected by mucopolysaccharidosis (MPS) type IH (Hurler Syndrome), an autosomal recessive metabolic disorder, are known to experience a range of musculoskeletal manifestations including spinal abnormalities, hand abnormalities, generalised joint stiffness, genu valgum, and hip dysplasia and avascular necrosis. Enzyme therapy, in the form of bone marrow transplantation, significantly increases life expectancy but does not prevent the development of the associated musculoskeletal disorders. We present the case of a 23-year-old woman with a diagnosis of Hurler syndrome with a satisfactory result following uncemented total hip arthroplasty.

Detection of urolithiasis using low-dose CT--a noise simulation study.

How does an acquisition at reduced doses using automatic tube current modulation techniques compare to the normal standard dose CT? Does it affect the sensitivity for detection of calcifications? CT raw data of 54 patients with suspected urolithiasis acquired with automatic tube current modulation techniques were used for image noise simulations with 100%, 50% and 25% dose simulated. Data were analyzed by independent readers with regard to the presence of urolithiasis, stone location, size, density and differential diagnoses. The mean effective dose per standard examination/50%/25% simulation was 7.3 mSv/3.8 mSv/1.9 mSv. Sensitivities/specificities for detection of urolithiasis were calculated for all dose simulations and resulted in 0.94/0.98 in the 50% dose level group and 0.82/0.97 in the 25% dose level group. Low-dose CT with tube current modulation can be used as a standard procedure for the evaluation of patients with suspected acute renal colic.