Publications by authors named "Lars Hildebrandt"

Kelps (Laminariales, Phaeophyceae) are foundation species along Arctic rocky shores, providing the basis for complex ecosystems and supporting a high secondary production. Due to ongoing climate change glacial and terrestrial run-off are currently accelerating, drastically changing physical and chemical water column parameters, e.g.

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Offshore wind farms (OWFs) pose new anthropogenic pressures on the marine environment as the erosion of turbine blades release organic and inorganic substances with potential consequences for marine life. In the present study, possible effects of the released particles and their chemical constituents on the metabolic profile of the blue mussel, Mytilus edulis, were investigated, utilizing H NMR spectroscopy. In the lab, mussels were exposed for 7 and 14 days to different concentrations (10 and 40 mg L) of microplastic (MP) particles which were derived from cryo-milled rotor blade coatings and core materials (glass fiber polymer, GFP).

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Photodegradation of plastic consumer products is known to accelerate weathering and facilitate the release of chemicals and plastic particles into the aquatic environment. However, these processes are complex. In our presented pilot study, eight plastic consumer products were leached in distilled water under strong ultraviolet (UV) light simulating eight months of Central European climate and compared to their respective dark controls (DCs).

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Article Synopsis
  • The rising issue of microplastics (MPs), tiny particles less than 5 mm, poses serious risks to both the environment and human health, finding their way into food and drink.
  • A study aimed to investigate the presence of MPs in human penile tissue sampled from patients undergoing surgery for inflatable penile prosthetics, using advanced imaging techniques for analysis.
  • Results showed that MPs were detected in 80% of samples, with common types found being polyethylene terephthalate and polypropylene, prompting concerns about the impact of these pollutants on sexual health.
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Concerns regarding microplastic (MP) contamination in aquatic ecosystems and its impact on seafood require a better understanding of human dietary MP exposure including extensive monitoring. While conventional techniques for MP analysis like infrared or Raman microspectroscopy provide detailed particle information, they are limited by low sample throughput, particularly when dealing with high particle numbers in seafood due to matrix-related residues. Consequently, more rapid techniques need to be developed to meet the requirements of large-scale monitoring.

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15 filtration samples were collected at eight locations onboard the RV Sonne (cruise SO279 in 2020) from 6 m water depth using a fractionated stainless-steel filtration unit. The size fraction > 300 μm was visually examined and potential microplastic particles were analyzed by ATR-FTIR spectroscopy. The treatment of size class 20 μm < d < 300 μm was based on enzymatic-oxidative microwave-assisted "one-pot" matrix digestion in conjunction with analysis of the microplastics by time-efficient LDIR imaging.

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This study examines laser microdissection pressure catapulting (LMPC) as an innovative method for microplastic research. Laser pressure catapulting as part of commercially available LMPC microscopes enables the precise handling of microplastic particles without any mechanical contact. In fact, individual particles with sizes between several micrometers and several hundred micrometers can be transported over centimeter-wide distances into a collection vial.

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Despite their presence in almost every technical device, little is known about the occurrence, distribution, and fate of technology-critical elements (TCEs) within the environment. Due to high economic demands and short product lifespans as well as low recycling rates, many TCEs appear to become emerging contaminants. Within the scope of this work, 57 sediment samples from the German part of the Rhine river, as well as various tributaries, were collected to study the occurrence and distribution of TCEs.

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Suspended particulate matter was collected from subsurface (6 m) water along an E-W transect through the tropical Indian Ocean using a specialized inert (plastic free) fractionated filtration system. The samples were subjected to a new microwave-assisted "one-pot" matrix removal (efficiency: 94.3% ± 0.

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For commonly applied microplastic sampling approaches based on filtration, high throughput and no size-discrimination are conflicting goals. Therefore, we propose two efficient centrifugal separators for small microplastic sampling, namely the utilization of a hydrocyclone as well as a continuous flow centrifuge. Thorough method optimization was followed by application in an extensive sampling study to investigate the separators' retention behavior for particulate plastics from estuarine waters.

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Microplastics are widely distributed in the environment and to define contamination hot spots, environmental samples have to be analysed by means of cost-as well as time-efficient and reliable standardised protocols. Due to the lipophilic characteristics of plastics, oil extraction as a fast and density-independent separation process is beneficial for the crucial extraction step. It was extensively validated (480 experiments) in two test setups by using canola oil and a cost-effective, plastic-free separation unit with spiked microplastics (19 different polymer types) in the density range from ρ = 11-1760 kg m and in the size range from 0.

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Determination of elemental mass fractions in sediments plays a major role in evaluating the environmental status of aquatic ecosystems. Herewith, the optimization of a new total digestion protocol and the subsequent analysis of 48 elements in different sediment reference materials (NIST SRM 2702, GBW 07313, GBW 07311 and JMC-2) based on ICP-MS/MS detection is presented. The developed method applies microwave acid digestion and utilizes HBF as fluoride source for silicate decomposition.

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The presence of microplastic (MP) particles in aquatic environments raised concern about possible enrichment of organic and inorganic pollutants due to their specific surface and chemical properties. In particular the role of metals within this context is still poorly understood. Therefore, the aim of this work was to develop a fully validated acid digestion protocol for metal analysis in different polymers, which is a prerequisite to study such interactions.

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Microplastic pollution within the marine environment is of pressing concern globally. Accordingly, spatial monitoring of microplastic concentrations, composition and size distribution may help to identify sources and entry pathways, and hence allow initiating focused mitigation. Spatial distribution patterns of microplastics were investigated in two compartments of the southern North Sea by collecting sublittoral sediment and surface water samples from 24 stations.

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Methane is an important greenhouse gas and tropospheric ozone precursor. Simultaneous observation of ethane with methane can help identify specific methane source types. Aerodyne Ethane-Mini spectrometers, employing recently available mid-infrared distributed feedback tunable diode lasers (DFB-TDL), provide 1 s ethane measurements with sub-ppb precision.

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Article Synopsis
  • When you're stressed for a short time, it can help your brain work better, which is good for survival.
  • But if you're stressed for a long time, like every day, it can really hurt your ability to think and remember things.
  • Scientists found that stress can change how brain cells connect, which helps with remembering things better, even if they don't fully understand how it works yet.
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Article Synopsis
  • * JAK2 and STAT3 isoforms, which are highly expressed in the brain, are localized in the postsynaptic density, indicating their importance in neuronal functions.
  • * This study reveals that the JAK/STAT pathway is essential for NMDA-receptor dependent long-term depression (NMDAR-LTD) in the hippocampus, linking it to synaptic plasticity in the brain beyond its roles in cytokine signaling.
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Recent years have shown the importance of tunable semiconductor lasers in optical sensing. We describe the status quo concerning DFB laser diodes between 760 nm and 3,000 nm as well as new developments aiming for up to 80 nm tuning range in this spectral region. Furthermore we report on QCL between 3 μm and 16 μm and present new developments.

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The crystal structures of divalent metal salts of trifluoromethyl sulfonic acid ("trifluoromethyl sulfonates") M(SO(3)CF(3))(2) (M = Mg, Ca, Ba, Zn, Cu) were determined from high-resolution X-ray powder diffraction data. Magnesium, calcium and zinc trifluoromethyl sulfonate crystallize in the rhombohedral space group R(bar)3. Barium trifluoromethyl sulfonate crystallizes in the monoclinic space group I2/a(C2/c) and copper trifluoromethyl sulfonate crystallizes in the triclinic group P(bar)1.

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The crystal structures of three polymorphic phases of rubidium trifluoromethyl sulfonate (RbSO3CF3, rubidium 'triflate') were solved from X-ray powder diffraction data. At room temperature, rubidium triflate crystallizes in the monoclinic space group Cm with lattice parameters of a = 19.9611(5) A, b = 23.

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Commercially available GaN-based laser diodes were antireflection coated in our laboratory and operated in an external cavity in a Littrow configuration. A total tuning range of typically 4 nm and an optical output power of up to 30 mW were observed after optimization of the external cavity. The linewidth was measured with a beterodyne technique, and 0.

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