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Background
The increased application of oxidative water treatment is associated with the presence of halogenated disinfection by-products (DBPs) in aqueous systems. Due to their hazard potential, permanent measurements of selected analytes are required to monitor their compliance with regulatory limits and guidelines. However, the simultaneous acquisition of alarming inorganic oxyhalide species by conventional ion chromatography (IC) is often impeded by co-elution of interfering analyte or matrix components, especially when DBPs of multiple halogens are present in solution. This necessitates a complementary, orthogonal detection setup that allows for an element-specific analysis.
N-Nitrosamines have long been identified as a relevant contaminant in potable water due to their identification as probable human carcinogens. Thus, highly sensitive detection of these pollutants in the ultra-trace range is imperative to comply with strict regulatory specifications. To this end, many institutions rely on mass spectrometry-based analysis methods, which have the disadvantage of being cost- and resource intensive. This study aims to develop, optimise, and evaluate a gas chromatography-drift tube-ion mobility spectrometry (GCIMS) based method with a twofold enrichment strategy consisting of solid phase extraction (SPE) followed by intube extraction (ITEX) of the eluate for nine different nitrosamines in drinking water in order to offer a sensitive alternative to the current state of the art. Optimisation of ITEX parameters was successfully performed using a simplex self-directing design approach, so that a calibration range between 5 and 50 ng/L could be achieved. The suitability of a linear regression model was demonstrated via analysis of variance (ANOVA) criteria. The analysis of different spiked drinking water samples allowed for the determination of the method's accuracy (27.3 - 114.5 % across different nitrosamine analytes and matrices, with most above 70 % recovery) and detection limits (1.12 - 12.48 ng/L across different nitrosamine analytes and matrices), which fall within the range of required limit values. Tested drinking waters show innate nitrosamine concentrations well below detection limits and can thus be deemed free from contaminants.
Analytical Chemistry II
(2025)
This workbook takes you through the successful textbook Skoog/Holler/Crouch, Instrumentelle Analytik and is designed primarily for self-study.In five parts, the lecture content of more advanced analytical chemistry is summarized and explained using selected examples: mass spectrometry and nuclear magnetic resonance spectroscopy deal with the investigation of molecules, and numerous electroanalytical methods such as potentiometry, coulometry, amperometry and voltammetry are also covered. An overview of more specialized analytical methods includes the use of radioactive substances and various fluorescence methods, as well as methods of information acquisition in the increasingly important electrochemical and optical sensor technology and their automation. The course concludes with a summary of various principles and application methods of statistics, which are simply indispensable in the context of analytics. In order to facilitate independent learning, references to essential sections and illustrations of the textbook are made throughout the book.
Background
Biological systems are often perceived as independent and consequently analyzed individually. In the field of omics, multiple disciplines target the study of specific types of molecules, such as genomics. The support of more data sources in these analyses is becoming more crucial for understanding the interplay of biological systems. However, this requires integration of heterogeneous knowledge, which is considered highly challenging in bioinformatics and biomedicine. Therefore, the R package Multipath was developed to model biological pathways as multilayered graphs and integrate influencing knowledge including proteins and drugs. In its previous form, Multipath generated multilayer models of BioPAX-encoded pathways and included features to integrate drug and protein information from DrugBank and UniProtKB respectively. Although the model showed remarkable utility, including further data sources ensures enriching and expanding its capabilities.
Results
In this paper, a new version Multipath 2.0 is presented. The update additionally supports the two databases KEGG Genes and OMIM, which serve as the source for gene and disease entries and interactions. Information on the interactions between the previously and newly added nodes are extracted and integrated. The Multipath 2.0 offers features to update the original multilayer model and integrate the corresponding nodes and edges into two additional layers referring to KEGG Genes and OMIM. Furthermore, the embedded nodes are inter- and intra-connected using interactions from the original and newly supported data sources.
Conclusion
The R Package Multipath is presented with the main functions that are newly developed to support the integration of the databases KEGG Genes and OMIM. The model comprises multiple information relevant to the analysis of pathway data, and offers a reproducible and simplified view of complex, intertwined systems. Through the application of such highly integrated models the inference of new knowledge becomes easier and contributes to many fields such as drug repurposing and biomarker discovery.
The growing interest toward biopolymers application in amphiphilic conditions prompts one to explore the preparation of fluorinated cellulosic materials. Cellulose (CE) and carboxymethylcellulose (CMC) are functionalized with highly fluorinated pendants, through a nucleophilic aromatic substitution on 3-pentadecafluoroheptyl-5-pentafluorophenyl-1,2,4-oxadiazole (FOX) leading to the corresponding fluorinated biopolymers CE-FOX and CMC-FOX. Structural and thermal stability confirm covalent attachment of the fluorinated moiety onto the cellulosic skeleton and highlighted an interesting 2D texture of the CMC-FOX material. Hybrid and amphiphilic features of CE-FOX and CMC-FOX, are confirmed by water and oil contact angle measurements. Applications as adsorbent material for organic contaminants from an aqueous solution are tested by previously incorporating the functional biopolymer into sodium alginate (SA) hydrogel beads. Rhodamine B (RhB) is used as a model wastewater pollutant. Fluoro-functionalization led to a three- to eightfold increase in the dye-removal efficiency of the SA-incorporated biopolymer with respect to the corresponding non-fluorinated material (from 11% to 48% for SA/CE vs SA/CE-FOX beads and from 11% to 94% for SA/CMC vs SA/CMC-FOX beads). Recyclability tests show good residual performance of SA/CMC-FOX beads after seven desorption/reuse cycles opening the way to more sustainable adsorbing processes for the removal of emerging pollutants from contaminated water.
Selenium is the third element of the group of chalcogens and is especially used in electrotechnical applications. Since many manufacturing processes use thin films of the material, knowledge of the mechanical properties is important for the detailed process layout. During the studies, the mechanical properties of trigonal selenium were determined. Therefore simulations of a uniaxial tensile test with a constant strain rate of 4.2⋅10–6/fs using molecular dynamic methods were performed. Finally a great dependency of the mechanical properties on temperature, direction and strain was observed. In particular, anisotropy in fracture behavior can be demonstrated. This can be explained by the anisotropy of trigonal selenium. In addition, a density distribution was calculated, showing that the mechanical properties are influenced by diffusion processes occurring at increased temperatures. The changes in dynamic processes point to a ductile-brittle transition.
Energetic materials (EMs) are compounds or mixtures of substances that contain both fuel and an oxidizer. When these materials react, they release thermal energy and produce a large amount of gas. The initiation of these substances can be triggered by mechanical, thermal, electrostatic, or optical influence. A distinction is made between materials that are capable of exploding and those that are hazardous due to their potential to explode [1].
EMs are not only used for military purposes, but also for civilian applications, such as in airbags, fireworks or explosives in mining. It has been a long way from the initial invention of the first explosives to their widespread use today. In 220 B.C., the Chinese accidentally discovered black powder. Centuries later, in the 13th and 14th centuries, the monk Roger Bacon and the German Berthold Schwarz researched the explosive for the first time in Europe. The military use of black powder began at this time. In 1846, nitroglycerine was discovered by Ascanio Sobrero. Alfred Nobel reduced the sensitivity of the highly sensitive nitroglycerine, thus making it possible to use the substance. The so-called dynamite was developed. Alfred Nobel also played an important role in the progress in the history of initial substances. His findings made it possible to reliably initiate dynamite by replacing black powder with mercury fulminate. This was replaced at the beginning of the 20th century by lead azide, which is still used today [2, 3].
In the following years, as demand increased, other explosives were developed and synthesised, many of which are still in use today. This led to the development of trinitrotoluene, triaminotrinitrobenzene and hexogen (RDX), for example. The focus in the development of energetic materials changed over time. In addition to reliability, the safe handling of the substances was often at the centre of research when it came to their commercial/military use. During the Second World War, for example, the use of polymer-bound explosives was favoured, resulting in the production of Semtex, a mixture of nitropenta (PETN) and RDX bound with styrene-butadiene rubber. Today, the focus of the development of energetic materials is on environmentally friendly research into materials in terms of sustainability and the improvement of existing properties (e.g. shorter initiation times for special military applications).
Yeast complementation assays provide limited informationon functional features of K+ channels
(2025)
We investigate to what extent yeast complementation assays, which in principle can provide large amounts of training data for machine learning models, yield quantitative correlations between growth rescue and single channel recordings. If this were the case, yeast complementation results could be used as surrogate data for machine learning-based channel design. Therefore, we mutated position L94 at the cavity entry of the model K+ channel KcvPBCV1 to all proteinogenic amino acids. The function of the WT channel and its mutants was investigated by reconstituting them in planar lipid bilayers and by their ability to rescue the growth of a yeast strain deficient in K+ uptake. The single channel data show a distinct effect of mutations in this critical position on unitary conductance and open probability, with no apparent causal relationship between the two functional parameters. We also found that even conservative amino acid replacements can alter the unitary conductance and/or open probability and that most functional changes show no systematic relationship with the physicochemical nature of the amino acids. This emphasizes that the functional influence of an amino acid on channel function cannot be reduced to a single chemical property. Mutual comparison of single channel data and yeast complementation results exhibit only a partial correlation between their electrical parameters and their potency of rescuing growth. Hence complementation data alone are not sufficient for enabling functional channel design; they need to be complemented by additional parameters like the number of channels in the plasma membrane.
Amide synthases catalyze the formation of macrolactam rings from aniline-containing polyketide-derived seco-acids as found in the important class of ansamycin antibiotics. One of these amide synthases is the geldanamycin amide synthase GdmF, which we recombinantly expressed, purified and studied in detail both functionally as well as structurally. Here we show that purified GdmF catalyzes the amide formation using synthetically derived substrates. The atomic structures of the ligand-free enzyme and in complex with simplified substrates reveal distinct structural features of the substrate binding site and a putative role of the flexible interdomain region for the catalysis reaction.
Unattended luggage or containers in public areas, such as railway stations and buildings, like airports, may trigger bomb disposal operations. While these instances frequently involve harmless forgotten bags, they can also signal the presence of unconventional explosives and incendiary devices, which may include chemical, biological, radiological, nuclear, and explosive (CBRNe) elements. Research aspects of this work include the development of a mobile laser cutting system (LCS) to enhance the capabilities of police bomb disposal units in neutralizing improvised explosive devices (IEDs) and forensic evidence collection, thereby improving the safety of the public and defusing experts. This article presents the results of the development of a breakthrough detection system using an appropriate sensor technology. Parameters are determined by means of sensory monitoring to cut through various materials without interacting with the layer behind them. The investigation includes real cutting tests with the mobile LCS on various materials. For example, breakthrough times for polystyrene ranged from 75 to 250 s depending on geometry, while sensor accuracy in detecting cutting progress exceeded 90%. Additionally, explosive residues as low as 10 ng were successfully detected post-cutting, highlighting the system’s forensic compatibility. The results show that sensor-based breakthrough detection is feasible for the laser cutting of IED-relevant objects.
Explosives trace residues on surfaces are utilized for forensic investigations and to check suspicious objects using technical and non-technical detection procedures. Data about expected trace contaminations after the handling of explosives and how they relate to a potential chemical background help to determine requirements and limitations of detection procedures. Often swab sampling is used for the analysis of surface contaminations. A wet swab sampling procedure was optimized for PETN, TNT and ammonium nitrate. Good results were achieved using PU-foam swabs wetted with a mixture of acetonitrile/water (90/10). The swabs were subsequently solvent extracted and analysed using LC-triple-quad-MS and ion-chromatography. The swabs were applied for the determination of explosives residues in a mock-up car scenario simulating one person loading the car with explosives followed by a short car travel by the same person. As test substances an ANFO, TNT and plasticized PETN were used. Additional samples were taken from indoor installations regularly used for the training of explosive detection dogs as well as other objects and buildings close by. The surface contaminations found in the investigated scenario ranged from the ng to the µg scale. The results indicate that simple cleaning procedures might not sufficient to remove explosives contaminations in training settings for explosives detection dogs. A significant spreading of explosive traces beyond direct contact with the person handling the explosive or with the explosive itself was not observed.
Plant-based bioactive compounds for substitution of petrol-based stabilisers in packaging materials
(2021)
Biopolymers are increasingly used to design drug delivery systems (DDSs), which incorporate therapeutic agents to deliver drugs precisely to the diseased sites with minimal side effects. An ideal DDS targets and controls drug release, protecting drugs from breakdown during transport. Due to their biocompatibility and biodegradability, the DDS made of biopolymers acts as a drug vehicle to reduce the side effects in the body [1].
In this preliminary work, chitosan hydrogels were prepared using 1,3,5-benzene tricarboxylic acid (BTC) as a crosslinker. In addition, the release behavior of the hydrophobic dye (Rhodamine B) from the chitosan hydrogels was examined. The dye was used in this work to visually track and quantify the loading and release behavior.
Ob in Windkraft-, Photovoltaikanlagen oder in der Elektromobilität – überall dort wo hohe Spannungen und Ströme transportiert werden müssen, sind Drahtverbindungen aus hochreinem Aluminium (Al-Gehalt mind. 99,99%) mit Durchmessern zwischen 125 μm und 500 μm unverzichtbar. Jährlich werden über 15 Trillionen Drahtbrücken in elektrischen Modulen verarbeitet. Im Betrieb müssen die Drähte wechselnde mechanische wie auch thermische Belastungen ertragen, die auf Dauer zu einem Ermüden der Drähte und damit zu einem Ausfall des Moduls führen können. Ziel der Promotion ist es daher ein Lebensdauermodell zu entwickeln mit dem die Zuverlässigkeit der Drähte vorhergesagt werden kann.
Illegal wildlife trade is a growing problem internationally. Poaching of animals not only leads to the extinction of populations and species but also has serious consequences for ecosystems and economies. This study introduces a molecular marker system that authorities can use to detect and substantiate wildlife trafficking. SNPSTR markers combine short tandem repeats with single nucleotide polymorphisms within an amplicon to increase discriminatory power. Within the FOGS (Forensic Genetics for Species Protection) project, we have established SNPSTR marker sets for 74 vertebrate species. On average, each set consists of 19 SNPSTR markers with 82 SNPs per set. More than 1300 SNPSTR markers and over 300 STR markers were identified. Also, through its biobanking pipeline, the FOGS project enabled the cryopreservation of somatic cells from 91 vertebrate species as well as viable tissues for later cell initiation from a further 109 species, providing future strategies for ex situ conservation. In addition, many more fixed tissues and DNA samples of endangered species were biobanked. Therefore, FOGS was an interdisciplinary study, combining molecular wildlife forensics and conservation tools. The SNPSTR sets and cell culture information are accessible through the FOGS database (https://fogs-portal.de/data) that is open to scientists, researchers, breeders and authorities worldwide to protect wildlife from illegal trade.
Introduction: Celiac Disease (CD) is a multisystemic auto-mmune disorder triggered by gluten in HLA genetically predisposed individuals. HLA-DQ genotyping is useful to assess the individual susceptibility to CD but still not sufficient for early diagnosis. Here, we propose HLA-DQA1 and HLA-DQB1 gene typing and exosomes characterization as new tool for CD prevention and diagnosis.
Methods: A Chilean population (n=30) was investigated for SNPs mutations in HLA Class II alleles associated with CD predisposition, using the GenoChip Food Technology. Exosomes have been isolated from donors’ serum by ultracentrifugation and characterized by Western Blotting (for CD63 and CD9) and transmission electron microscopy. Exosomes were also studied for their interleukin-1ra content.
Results: Among the studied population, 45.84, 37.46, and 16.70% were carrying alleles encoding for MHC-DQ heterodimers associated with extremely high, high, and extremely low risk to develop CD. The exosome size decreased significantly (p<0.05) when derived from extremely low CD risk donors (44.58 ± 7.88 nm). In parallel, isolated Exosomes from donors with high and extremely high CD risk showed higher IL-1ra content. The values increase within the extremely high-risk group (108.8 ± 15.91 and 148.8 ± 12.37 pg/mL), as the CD persons were not following any treatment. However, these values were lower (52.50 ± 3.54 and 48.75 ± 6.52 pg/mL) in exosomes isolated from CD patients after treatment.
Conclusion: A relationship between exosomes’ size and IL-1ra content, and genetic susceptibility for CD has been observed, suggesting their possible use as biomarkers for CD prevention and diagnosis.
Background. This study was performed to investigate the influence of a short-term treatment with pioglitazone versus placebo on inflammatory activation of mononuclear cells (mRNA expression/protein secretion of inflammatory markers). Methods and Results. Sixty-three patients with well-controlled type 2 diabetes (52 males, 11 females, age (Mean ± SD): 66 ± 7 yrs, disease duration: 6.6 ± 9.6 yrs, HbA1c: 6.7 ± 0.6%) were randomized to additional 45 mg of pioglitazone or placebo to their existing metformin and sulfonylurea therpay for four weeks in a double-blind study design. Protein risk marker levels (hsCRP, MMP-9, MCP-1, etc.) and the expression of NFκB subunits and NFκB-modulated cytokines from isolated peripheral monocyte/macrophages were determined at baseline and endpoint. There were no changes in HbA1c, but significant biomarker improvements were seen with pioglitazone only. The mRNA marker expression was downregulated by pioglitazone and further up-regulated with placebo (e.g., P105 pioglitazone: -19%/placebo: +6%, RelA: -20%/+2%, MMP-9: -36%/+9%, TNFα: -10%/+14%, P < 0.05 between groups in all cases). Conclusions. Pioglitazone very rapidly down-regulated the activated state of peripheral monocytes/macrophages as assessed by mRNA expression of NFκB and NFκB-modulated cytokines and decreased plasma levels of cardiovascular risk marker proteins independent of glycemic control.
AIM
Insulin treatment is considered to be the final option for patients with progressive type 2 diabetes. This study investigated, whether reconverting type 2 patients from insulin treatment to oral treatment using pioglitazone is possible without deterioration of blood glucose control.
METHODS
The PioSwitch study was a prospective, open label, proof of concept study. Thiazolidinedione-naïve patients with residual beta-cell function were switched from an existing insulin therapy to treatment with pioglitazone and glimepiride for 6 months. Efficacy was assessed by laboratory parameters and scores for evaluation of metabolic control, beta-cell function, insulin resistance and cardiovascular risk.
RESULTS
In total, 98 patients [66 men, 32 women, age (mean +/- s.d.): 59 +/- 9 years; disease duration: 5.6 +/- 3.6 years; Hemoglobin A1c (HbA1c): 6.9 +/- 0.8%; body mass index (BMI): 33.9 +/- 5.2 kg/m(2), initial daily insulin therapy dose: 0.36 +/- 0.3 U/kg body weight] out of 117 screened patients were treated. During the observation period, 23 patients were prematurely terminated because of an increase in HbA1c from baseline > 0.5% or other reasons. In 75 patients (76%), no deterioration of glucose metabolism occurred and additional improvements were seen in the majority of the observation parameters [baseline vs. endpoint; HbA1c: 6.79 +/- 0.74%/6.66 +/- 0.69% (p < 0.05), glucose: 6.4 +/- 1.5/5.2 +/- 1.4 mmol/l (p < 0.001), adiponectin: 7 +/- 3 mg/l/17 +/- 8 mg/l (p < 0.001), C-peptide: 987 +/- 493/1756 +/- 789 (p < 0.001), sensitivity index derived from the intravenous glucose tolerance test (SI(ivGTT)): 1.21 +/- 0.85/1.49 +/- 0.95 (p < 0.05), hsCRP: 3.3 +/- 2.4/2.6 +/- 2.4 mg/l (p < 0.01), macrophage chemo-attractant protein 1 (MCP1): 487 +/- 246/382 +/- 295 ng/l (p < 0.05)]. BMI increased from 33.8 +/- 5.1 to 34.4 +/- 5.3 kg/m(2) (p < 0.001).
CONCLUSIONS
The switch from insulin therapy resulting in a moderately HbA1c level, to oral treatment with pioglitazone was successful in a majority of patients with sufficient residual beta-cell function. It allows a simple and less expensive therapy with a better cardiovascular risk marker profile.
Die Nachfrage nach nachhaltigen, umweltfreundlichen und CO2-reduzierten Dämmstoffen steigt stetig. Insbesondere im Hinblick auf den fortschreitenden Klimawandel, sind die Reduzierung des CO2-Ausstoßes, die Verringerung des Energieverbrauchs von Gebäuden, sowie die Schonung natürlicher Ressourcen, wichtige Forderungen für den Erhalt der Umwelt. Zu den am häufigsten eingesetzten Wärmedämmstoffen zählen derzeit Polystyren, Polyurethan und Mineralwolle, für deren Herstellung jedoch eine erhebliche Menge an Energie eingesetzt werden muss. Eine sinnvolle Alternative stellen Dämmstoffe auf Basis nachwachsender Rohstoffe dar. Als sehr aussichtsreiche Gruppe von nachwachsenden Rohstoffen gelten mehrjährige, schnellwachsende Low-input Kulturen, wie das aus dem ostasiatischen Raum stammende Großgras Miscanthus. Ziel dieser Arbeit liegt in der Entwicklung und Charakterisierung Miscanthus faserverstärkter Geopolymerschäume für den Einsatz als Dämmstoff. Dazu wurden zunächst die Grundlagen aus Bereichen nachwachsender Rohstoffe, Dämmstoffe, Schaumtechnologie sowie Geopolymeren zusammengetragen. Ein besonderer Schwerpunkt lag dabei auf der Herstellung von naturfaserverstärkten Geopolymerschäumen. Ausgehend von den Grundlagen wurde der Ausgangsstoff Miscanthus hinsichtlich seiner Dämmeigenschaften, wie Wärmeleitfähigkeit und Porenstruktur charakterisiert und im Anschluss durch Kombination mit geschäumten Geopolymeren, Miscanthus faserverstärkte Dämmstoffplatten hergestellt. Mittels statistischer Versuchsplanung wurde im nächsten Schritt der Einfluss verschiedener Faktoren (Fasergehalt, Faserlänge, Aushärtungstemperatur, Menge an Schaumbildner, Gehalt an pyrogener Kieselsäure und spezifische Oberfläche der pyrogenen Kieselsäure) auf die Wärmeleitfähigkeit und Druckfestigkeit der hergestellten Dämmstoffe untersucht. Im Ergebnis konnte dabei ein signifikanter Einfluss des Fasergehalts, der Faserlänge und der Menge an Schaumbildner festgestellt werden. Untersuchungen zur Porosität, mineralogischen Zusammensetzung, Molekülstruktur, sowie Mikrostruktur ergänzen diese Ergebnisse. Abschließend wurde auf Grundlage der statistischen Daten eine optimale Zusammensetzung mit niedriger Wärmeleitfähigkeit und gleichzeitig hoher Druckfestigkeit ermittelt.
The demand for sustainable, environmentally friendly, and low-carbon insulation materials is constantly increasing. Especially considering the progression of climate change, reducing CO2 emissions, reducing the energy consumption of buildings, and conserving natural resources are all important requirements for preserving the environment. The most frequently used thermal insulation materials currently include polystyrene, polyurethane, and mineral wool, but a considerable amount of energy is used in their production. Insulation materials based on renewable raw materials are a sensible alternative. An extremely promising group of renewable raw materials includes multi-year, fast-growing low-input crops, such as the tall grass Miscanthus from East Asia. The aim of this paper is the development and characterization of Miscanthus fiber-reinforced geopolymer foams for use as insulation material. To this end, the basics of renewable raw materials, insulation materials, foam technology and geopolymers were compiled first. Particular attention was paid to the production of natural fiber stabilized geopolymer foams. Starting from the basics, the raw material Miscanthus was characterized with regard to its insulating properties such as thermal conductivity and pore structure, and subsequently Miscanthus fiber-reinforced insulation boards were produced by combining with foamed geopolymers. In the next step, the influence of various factors (fiber content, fiber size, curing temperature, foaming agent content, content of fumed silica and specific surface area of the fumed silica) on the thermal conductivity and compressive strength of the produced insulating materials was investigated by means of statistical experiment planning. As a result, it could be determined that the fiber content, fiber size and foaming agent content had a significant influence. Investigations concerning porosity, mineralogical composition, molecular structure, and microstructure complement these results. Finally, an optimal composition with low thermal conductivity, and at the same time high compressive strength, was determined based on the statistical data.
Pollution with anthropogenic waste, particularly persistent plastic, has now reached every remote corner of the world. The French Atlantic coast, given its extensive coastline, is particularly affected. To gain an overview of current plastic pollution, this study examined a stretch of 250 km along the Silver Coast of France. Sampling was conducted at a total of 14 beach sections, each with five sampling sites in a transect. At each collection site, a square of 0.25 m2 was marked. The top 5 cm of beach sediment was collected and sieved on-site using an analysis sieve (mesh size 1 mm), resulting in a total of approximately 0.8 m3 of sediment, corresponding to a total weight of 1300 kg of examined beach sediment. A total of 1972 plastic particles were extracted and analysed using infrared spectroscopy, corresponding to 1.5 particles kg−1 of beach sediment. Pellets (885 particles), polyethylene as the polymer type (1349 particles), and particles in the size range of microplastics (943 particles) were most frequently found. The significant pollution by pellets suggests that the spread of plastic waste is not primarily attributable to tourism (in February/March 2023). The substantial accumulation of meso- and macro-waste (with 863 and 166 particles) also indicates that research focusing on microplastics should be expanded to include these size categories, as microplastics can develop from them over time.
Due to the toxicity and negative environmental impact of lead- and chromate(IV and VI)-based delay compositions, alternative substance mixtures are required to be investigated as possible substitutes for pyrotechnic materials. Therefore, the Mg/ CaO2 and Mg/Li2O2 delay compositions were subject of this work. These mixtures were processed into pellets with the aid of the dry binders HPMC, MgSt, PEG1, PEG2 and PVP and used in delay elements. The binder content used for all the composition was 5 wt%. Burning rates were investigated while taking the influence of oxidizer particle size and the effect of different binders into account. The results show that the combustion rate can be adjusted both via the grain size and by means of the various binders. Further, the impact of the different binders on the ignition temperature of the Mg/Li2O2 and Mg/CaO2 compositions was measured. The compositions were also classified as insensitive to impact and friction. However, during preparation of delay pallets, unintended ignition of pellets occurred while using the HPMC, PEG1, PEG2 and PVP binders. For this reason, safety measures should be followed and special care should be taken while preparing delay pellets. While the peroxides could be identified with Raman spectroscopy, no peroxide residue was found in the reaction products of both peroxide magnesia mixtures.
Triacetone triperoxide (TATP) and Hexamethylene triperoxide diamine (HMTD), known for their propensity towards use in improvised explosive devices due to facile synthesis from readily accessible precursors, present a considerable security challenge. Their sensitivity to mechanical stimuli, such as impact and friction, as well as to thermal input, necessitates the development of advanced detection methodologies. This study is dedicated to evaluate the influence of varied laser beam parameters during radiation on these peroxide-based energetic materials. A novel approach for the controlled energy delivery to substances under investigation involves the application of coatings with predefined absorption coefficients. This technique, coupled with the careful selection of laser parameters, enables the controlled local initiation of reaction in the energetic material without reaching the threshold for mass combustion, thereby avoiding detonation or deflagration. The experimental setup involves the laser irradiation of defined quantities of graphite-coated TATP and HMTD, with the subsequent laser processing being monitored using a sensitive microphone. This set-up enables a detailed investigation of the physical phenomena that manifest themselves during the interaction and thus contributes to the state of knowledge about the safe handling and detection of these energetic materials.
Aberrant Ras homologous (Rho) GTPase signalling is a major driver of cancer metastasis, and GTPase-activating proteins (GAPs), the negative regulators of RhoGTPases, are considered promising targets for suppressing metastasis, yet drug discovery efforts have remained elusive. Here, we report the identification and characterization of adhibin, a synthetic allosteric inhibitor of RhoGAP class-IX myosins that abrogates ATPase and motor function, suppressing RhoGTPase-mediated modes of cancer cell metastasis. In human and murine adenocarcinoma and melanoma cell models, including three-dimensional spheroid cultures, we reveal anti-migratory and anti-adhesive properties of adhibin that originate from local disturbances in RhoA/ROCK-regulated signalling, affecting actin-dynamics and actomyosin-based cell-contractility. Adhibin blocks membrane protrusion formation, disturbs remodelling of cell-matrix adhesions, affects contractile ring formation, and disrupts epithelial junction stability; processes severely impairing single/collective cell migration and cytokinesis. Combined with the non-toxic, non-pathological signatures of adhibin validated in organoids, mouse and Drosophila models, this mechanism of action provides the basis for developing anti-metastatic cancer therapies.
Background: The global rate of Caesarean section (CS) is 21.1 % (2021) and is rising worldwide. CS presents the third highest cumulative incidence for surgical site infections. Maternal infections around the time of childbirth account for 1 out of 10 maternal deaths worldwide. Therefore, perioperative antibiotic prophylaxis (PAP) during CS is common standard of care and part of numerous recommendations from expert bodies such as the World Health Organization (WHO) and different national gynecological professional associations. According to these, first and second generation cephalosporins like cefuroxime are the agents of choice for this indication. In fact, the use of PAP significantly reduces maternal morbidity and mortality rates. Whereas the side effect of this measure on the microbiome of the newborn has been the subject of repeated clinical studies, data on specific and especially long-term effects on the gut microbiome of the mothers are still lacking. MAMA is the first study to specifically and systematically investigate this question.
The epithelial sodium channel (ENaC) plays a key role in osmoregulation in tetrapod vertebrates and is a candidate receptor for salt taste sensation. There are four ENaC subunits (alpha, beta, gamma, & delta) which form alpha beta gamma or delta beta gamma-ENaCs. While alpha beta gamma-ENaC is a maintenance protein controlling sodium and potassium homeostasis, delta beta gamma-ENaC might represent a stress protein monitoring high sodium concentrations. The delta-subunit emerged with water-to-land transition of tetrapod vertebrate ancestors. We investigated the evolutionary path of ENaC-coding genes in Cetartiodactyla, a group comprising even-toed ungulates and the cetaceans (whales/dolphins) which transitioned from terrestrial to marine environments in the Eocene. The genes SCNN1A (alpha-ENaC), SCNN1B (beta-ENaC) and SCNN1G (gamma-ENaC) are intact in all 22 investigated cetartiodactylan families. While SCNN1D (delta-ENaC) is intact in terrestrial Artiodactyla, it is a pseudogene in 12 cetacean families. A fusion of SCNN1D exons 11 and 12 under preservation of the open reading frame was observed in the Antilopinae, representing a new feature of this clade. Transcripts of SCNN1A, SCNN1B and SCNN1G were present in kidney and lung tissues of Bottlenose dolphins, highlighting alpha beta gamma-ENaC's role as a maintenance protein. Consistent with SCNN1D loss, Bottlenose dolphins and Beluga whales did not show behavioural differences to stimuli with or without sodium in seawater-equivalent concentrations. These data suggest a function of delta-ENaC as a sodium sensing protein which might have become obsolete in cetaceans after the migration to high-salinity marine environments. Consistently, there is reduced selection pressure or pseudogenisation of SCNN1D in other marine mammals, including sirenians, pinnipeds and sea otter.
The lysosomal cation channel TMEM175 is crucial for maintaining lysosomal function and pH homeostasis, and its aberrant function is linked to Parkinson’s disease (PD). While TMEM175 activity was first interpreted in the context of its potassium (K+) selective conductance, subsequent studies revealed also a substantial permeability to protons (H+). Here we dissect the complex changes in TMEM175 conductance and current reversal voltages in response to pH jumps on the luminal side of the channel protein. In whole-cell patch clamp experiments with plasma membrane redistributed TMEM175 we show that a pH jump from symmetrical pH 7.4 to pH 4.7 on the luminal side triggers a continuous rise in inward and outward current, concomitant with a transient positive excursion of the reversal voltage (Erev). The peak Erev shift remains almost 100 mV below the estimated equilibrium voltage for protons and shows little sensitivity to the K+ gradient. The data are consistent with a scenario in which a TMEM175 mediated proton flux elicits a fast collapse of the pH gradient. In MD simulations we identify the luminal H57 as titratable partner for the formation of intra- and inter-subunit salt bridges with D279 and E282 for stabilizing the channel open state. This presumed gating function is confirmed by mutational studies and lysosomal patch-clamp experiments in which a H57Y mutant exhibits a reduced pH dependency of activation. Our findings contribute to a better comprehension of TMEM175’s complex electrophysiological properties and foster understanding of TMEM175 as a pharmacological target for neurodegenerative disease therapy.
Effects of Stretch-Bending Straightening on the Tensile Properties of Cold Rolled Packaging Steel
(2024)
Achieving perfect flatness, tension-free surfaces, and exceptional resistance to spring back are important characteristics of packaging steel, setting the standard for high-quality material performance. To guarantee these crucial parameters, the implementation of the stretch-bending process at the final stage of the production route is indispensable. Besides improving the flatness properties, the induced plastic deformation results in an accompanying change in the mechanical properties. This investigation focuses on understanding this change in mechanical properties due to different stretch-bending straightening process parameters. A multivariate predictive model is created to calculate a process window for achieving the desired flatness and also mechanical properties in the production of packaging steel. This model is validated by experiments with a laboratory facility.
Modern forensic DNA quantitation assays provide information on the suitability of a DNA extract for a particular type of analysis, on the amount of sample to put into the analysis in order to yield an optimal (or best possible) result, and on the requirement for optional steps to improve the analysis. To achieve a high sensitivity and specificity, these assays are based on quantitative PCR (qPCR) and analyze target DNA loci that are present in multiple copies distributed across the genome. These target loci allow the determination of the amount of DNA, the degree of DNA degradation, and the proportion of DNA from male contributors. In addition, internal control DNA of a known amount is analyzed in order to inform about the presence of PCR inhibitors. These assays are nowadays provided as commercial kits that have been technically validated and are compatible with common qPCR instruments. In this review, the principles of forensic qPCR assays will be explained, followed by information on the nature of DNA loci targeted by modern forensic qPCR assays. Finally, we critically draw attention to the current trend of manufacturers not to disclose the exact nature of the target loci of their commercial kits.
Design and characterization of geopolymer foams reinforced with Miscanthus x giganteus fibres
(2024)
This paper presents the results of the optimisation and characterization of Miscanthus fibre reinforced geopolymer foams based on fly ash and represents an important step forward in the development of a sustainable and environmentally friendly insulation material. Miscanthus belongs to a promising group of renewable raw materials with favourable thermal insulation properties. Design of experiment (DoE) were used to optimize the thermal conductivity and compressive strength of Miscanthus x giganteus reinforced geopolymer foams. In addition, the samples was analyzed using X-ray diffraction (XRD), Field emission scanning electron microscopy (SEM) and Fourier-Transform Infrared Spectroscopy (FTIR). Mixtures with a low thermal conductivity of 0.056 W (m K)−1 and a porosity of 79 vol% achieved a compressive strength of only 0.02 MPa. In comparison, mixtures with a thermal conductivity of 0.087 W (m K)−1 and a porosity of 58 vol% achieved a compressive strength of 0.45 MPa. Based on the determined parameters especially due to the low compressive strength, an application as cavity insulation or insulation between rafters is possible.
The goal of this study was to explore a route for introducing functionalities into agarose-based hydrogels to tune the physical, chemical, and biological properties. Several agarose derivatives were prepared by homogeneous synthesis, including anionic agarose sulfates (ASs), reactive azido agaroses (AZAs), and cationic agarose carbamates (ACs), as well as agarose tosylates (ATOSs) and agarose phenyl carbonates (APhCs). The products were characterized in terms of their molecular structure and solubility behavior. The results suggest that the native gel-forming ability of agarose is retained if the introduced functionalities are hydrophilic, and the overall degree of substitution is low (DS < 0.5). Thus, functional hydrogels from several agarose derivatives could be obtained. The mechanical stability of the functional hydrogels was decreased compared to native agarose gels but was still in a range that enables safe handling. An increase in mechanical strength could be achieved by blending functional agarose derivatives and agarose into composite hydrogels. Finally, it was demonstrated that the novel functional agarose hydrogels are biocompatible and can potentially stimulate interactions with cells and tissue.
The autocatalyzed ethanolic organosolv process is gaining increasing attention for the sulfur-free isolation of lignin, which is subsequently used as a renewable substitute for various fossil-based applications. For the first time, the mechanochemical influence of seven different particle sizes of two different biomasses on the respective organosolv lignin structure is examined. Wine pruning (Pinot Noir) and wine pomace (Accent) are used for organosolv process with particle sizes ranging from 2.0–1.6 mm to less than 0.25 mm. As particle size decreases, the weight-average molecular weight increases, while the total phenol content decreases significantly. Additionally, the distribution of the lignin-typical monolignols and relevant substructures, as determined by two-dimensional heteronuclear nuclear magnetic resonance spectra single quantum coherence (HSQC), is observed. The degree of grinding of the biomass has a clear chemical–structural influence on the isolated HG and HGS organosolv lignins. Therefore, it is crucial to understand this influence to apply organosolv lignins in a targeted manner. In the future, particle size specifications in the context of the organosolv process should be expressed in terms of distribution densities rather than in terms of a smaller than specification.
The treatment of ultrapure water with electrochemically produced O3 is a common means for disinfection yet leads to the formation of a variety of reactive oxygen species (ROS). The present study draws a comprehensive comparison between three commonly used photometric and fluorometric assays for ROS analysis and quantifies the individual signal responses for dissolved O3, ·OH and H2O2, respectively, to account for cross-sensitivities. By calibrating all combinations of assays and analytes, we developed a quantification procedure to reliably determine the actual ROS composition in ultrapure water environments for different operation conditions of a membrane water electrolyzer with PbO2 anodes down to concentrations of 0.97 μg L−1. While the ·OH formation rate can be described linearly over the observed current density range, substantial O3 evolution is only found for current densities of 0.75 A cm−2 and above (up to 3.7 μmol h−1 for J = 1.25 A cm−2). The formation of H2O2 is only observed when an organic carbon source is introduced into the solution. We further quantify the interference of H2O2 with the reading of the oxidation-reduction potential as a common water parameter and elaborate on its validity to monitor the peroxone process when both H2O2 and O3 are present simultaneously.
To respond to the increasing demand for hyaluronic acid (HA) in dietary supplements (DSs) and nutricosmetics marketed for the treatment of osteoarthritis or moistening, it is essential to have an accurate and reliable method for its analysis in the final products. The study aimed to develop and validate alternative method for the quality control of HA in DSs using low-field (LF) and high-field (HF) nuclear magnetic resonance (NMR) spectroscopy at 80 MHz and 600 MHz, respectively. Moreover, chondroitin sulphate (CH), another active ingredient in DSs, can be simultaneously quantified. The 1H-NMR methods have been successfully validated in terms of limit of detection (LOD) and limit of quantitation (LOQ), which were found to be 0.1 mg/mL and 0.2 mg/mL (80 MHz) as well as 0.2 mg/mL and 0.6 mg/mL (600 MHz). Recovery rates were estimated to be between 92 and 120% on both spectrometers; precision including sample preparation was found to be 4.2% and 8.0% for 600 MHz and 80 MHz, respectively. Quantitative results obtained by HF and LF NMR were comparable for 16 DSs with varying matrix. HF NMR experiments at 70 ℃ serve as a simple and efficient quality control tool for HA and CH in multicomponent DSs. Benchtop NMR measurements, upon preceding acid hydrolysis, offer a cost-effective and cryogen-free alternative for analyzing DSs in the absence of CH and paramagnetic matrix components.