Publications by authors named "Matthias Maier"

Since widespread vaccination against COVID-19, the development of effective antiviral drugs, and the decreasing number of patients with COVID-19 in intensive care, the risk from SARS-CoV-2 infection appears less threatening. However, studies show that a significant number of patients suffer from long-term sequelae, even months after SARS-CoV-2 infection. The so-called post-COVID syndrome (PCS) often presents a diagnostic and treatment challenge for physicians.

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Despite the great success of the concept of doping organic compounds with BN units to access new materials with tailored properties, its use in polymer chemistry has only been realized quite recently. Herein, we present a comprehensive study of oligo- and poly(arylene iminoborane)s comprising a backbone of phenylene or thiophene moieties, as well as combinations thereof, linked via B=N units. The novel polymers can be regarded as BN analogues of poly(p-phenylene vinylene) (PPV) or poly(thiophene vinylene) (PTV) or their copolymers.

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An unprecedented poly(thiophene iminoborane)-a boron-nitrogen analogue of the well-established conjugated organic polymer poly(thiophene vinylene)-is presented. The polymer synthesis is achieved by selective Si/B exchange polycondensation of a 2,5-diborylthiophene with a 2,5-diaminothiophene derivative. For the latter, a facile synthetic strategy is devised, which makes this versatile, strongly electron-releasing building block easily accessible.

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Treatment of an -silyl--chloro-aminoborane with substoichio-metric quantities of MeSiOTf afforded B-N coupling, whereas activation with 5 mol% of Ag[Al{OC(CF)}] led to Cl/Me exchange between the boron and the silicon center. Combined experimental and computational studies of the latter process support a chain reaction that is initiated by nucleation-limited chloride abstraction.

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Hydrogels are key components in several biomedical research areas such as drug delivery, tissue engineering, and biofabrication. Here, a novel ABA-type triblock copolymer comprising poly(2-methyl-2-oxazoline) as the hydrophilic A blocks and poly(2-phenethyl-2-oxazoline) as the aromatic and hydrophobic B block is introduced. Above the critical micelle concentration, the polymer self-assembles into small spherical polymer micelles with a hydrodynamic radius of approx 8-8.

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Amphiphilic block copolymers that undergo (reversible) physical gelation in aqueous media are of great interest in different areas including drug delivery, tissue engineering, regenerative medicine, and biofabrication. We investigated a small library of ABA-type triblock copolymers comprising poly(2-methyl-2-oxazoline) as the hydrophilic shell A and different aromatic poly(2-oxazoline)s and poly(2-oxazine)s cores B in an aqueous solution at different concentrations and temperatures. Interestingly, aqueous solutions of poly(2-methyl-2-oxazoline)--poly(2-phenyl-2-oxazine)--poly(2-methyl-2-oxazoline) (PMeOx--PPheOzi--PMeOx) undergo inverse thermogelation below a critical temperature by forming a reversible nanoscale wormlike network.

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Two isostructural and isoelectronic group VI azide complexes of the general formula [M(η-allyl)(N)(bpy)(CO)] with M = Mo, W and bpy = 2,2'-bipyridine were prepared and fully characterized, including X-ray structure analysis. Both reacted smoothly with electron-poor alkynes such as dimethyl acetylenedicarboxylate (DMAD) and 4,4,4-trifluoro-2-butynoic acid ethyl ester in a catalyst-free room-temperature iClick [3 + 2] cycloaddition reaction. Reaction with phenyl(trifluoromethyl)acetylene, on the other hand, did not lead to any product formation.

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Background: The clinical effectiveness of fecal microbiota transplant (FMT) for the treatment of recurrent Clostridium difficile infections (rCDI) has been demonstrated in randomized controlled trials. To assess the current status of FMT in Germany with respect to active centers, local standards, clinical effectiveness and safety, the MicroTrans Registry (NCT02681068) was established.

Methods: In a long-term retrospective multicenter observational study by the German Clinical Microbiome Study Group (GCMSG), primary and secondary cure on day 30 and 90, as well as occurrence of treatment-related adverse events were assessed.

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Background And Objective: To describe optical coherence tomography angiography (OCTA) findings in patients with acute central serous chorioretinopathy (CSC) compared to conventional imaging methods.

Patients And Methods: A consecutive series of 11 eyes from 10 healthy patients with acute CSC were included and underwent fluorescein angiography (FA), indocyanine green angiography (ICGA), OCT, fundus autofluorescence (FAF), and OCTA. Obtained OCTA images were evaluated for the presence of serous detachments of the neurosensory retina, leakage points, or other altered findings and compared to conventional imaging devices.

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Purpose: To determine which MR-arthrography findings are associated with positive hip joint distraction.

Materials And Methods: One hundred patients with MR arthrography of the hip using axial traction were included. Traction was applied during the MR examination with an 8 kg (females) or 10 kg (males) water bag, attached to the ankle over a deflection pulley.

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Purpose: To retrospectively evaluate the re-injection interval, efficacy and safety of dexamethasone (DEX) intravitreal implant 0.7 mg in the treatment of macular oedema (ME) due to retinal vein occlusion (RVO) in Germany in 2009-2012.

Methods: Retrospective, multicentre, anonymised observational study of data collected from the first DEX implant 0.

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The purpose of the present study was to assess the hazard potentials of contaminated suspended particulate matter (SPM) sampled during a flood event for floodplain soils using in vitro bioassays and chemical analysis. Sediment-contact tests were performed to evaluate the direct exposure of organisms to native soils and SPM at two different trophic levels. For comparison, acetonic extracts were tested using both contact tests and additionally two cell-based biotests for cytotoxicity and Ah receptor-mediated activity (EROD-Assay).

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Purpose: To determine the spectrum of magnetic resonance (MR) imaging findings at the calcaneal attachment of the plantar fascia in asymptomatic volunteers.

Materials And Methods: The study was approved by the institutional review board, and informed consent was obtained from all subjects. MR imaging was performed in 77 asymptomatic volunteers (mean age, 48.

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We present a rare cause of cervical myelopathy produced by an engorged suboccipital epidural venous plexus due to chronic cerebrospinal fluid (CSF) overdrainage. A 17-year-old boy with obstructive hydrocephalus due to a retrocerebellar cyst and secondary implantation of a ventricloperitoneal shunt (VP-shunt) presented with progressive spastic tetraparesis. MRI imaging revealed myelopathy due to significant compression of the cervical spinal cord by engorged epidural veins.

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The miniemulsion process is used as a new route for the preparation of enzyme-responsive nanocapsules with payload-release properties. Peptide-based hybrid nanocapsules are prepared via interfacial polyaddition containing a water-soluble dye that is efficiently encapsulated inside. The influence of the synthetic parameters as the functionality of the peptide and the nature of the dispersed phase on the structure of the nanocapsules were investigated.

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Orientation of the division axis can determine cell fate in the presence of morphogenetic gradients. Understanding how mitotic cells integrate directional cues is therefore an important question in embryogenesis. Here, we investigate the effect of dynamic shear forces on confined mitotic cells.

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A method for quality screening is suggested to detect volatile impurities in inorganic coagulants that are used for drinking water treatment. Static headspace gas chromatography with mass spectrometry detection (HS-GCMS) is sensitive and selective to detect volatiles in low concentrations. This study has discovered that volatile organic impurities are detectable in ferric and aluminium-based coagulants which are used for drinking water treatment.

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The present work describes the investigation of the formation of oxidation by-products of the iodinated X-ray contrast medium (ICM) iomeprol during ozonation in water treatment. Bench-scale investigations revealed that ICM can be partly oxidized during ozonation processes, whereas the ionic diatrizoic acid showed the lowest reactivity. Iomeprol, as a representative of ICM, was not fully mineralized during ozonation.

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A monitoring programme was carried out in order to determine iodinated X-ray contrast media (ICM) in the River Danube and to investigate the raw water quality for drinking water production at Langenau waterworks. The study revealed that the maximum concentrations of ICM (over 500 ng l(-1) for diatrizoic acid and iopamidol) were found in 2h-composite samples taken from the downstream of the Ulm/Neu-Ulm metropolitan area. By means of a concentration profile over one month the highest ICM concentrations were observed on weekdays.

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Background And Aims: Persons with a familial risk of colorectal cancer (CRC) account for about 25% of all CRC cases. The adenoma prevalence in relatives of CRC patients 50-60 years of age is 17-34%; data on younger individuals are scarce. Our aim was to prospectively define the adenoma prevalence in 40- to 50-year-old first-degree relatives of CRC patients compared to controls.

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