Hydrothermal vents and their impact on paleoenvironmental proxies

Trace metals such as cobalt, copper, molybdenum, and uranium have been used as redox and productivity proxies to interpret paleoenvironments. However, the presence of a hydrothermal vent could potentially alter the interpretations if metal-rich fluids from these vents serve as another source for these specific trace metals into the sediment. To date, there are no published studies on the impact of hydrothermal vent deposits on paleoproxies. In this thesis the impact of hydrothermal vents on trace metal deposition in the surrounding sediments was investigated. Two cores were compared for their elemental composition applying a multi-acid total digestion and inductively coupled plasma mass spectrometry analysis. The comparison was carried out on samples collected during the RV Polarstern Expedition PS119 in the Scotia Sea, on a core collected on the east side of an ocean ridge containing a hydrothermal vent field and another core from the west side of the ridge. The direction of the Antarctic Circumpolar Current is from west to east in the Scotia Sea. Thus, only the site on the east side of the hydrothermal vent could potentially receive hydrothermal vent plume deposits. Concentrations of the proxies, specifically molybdenum, copper, and cobalt are higher in the core on the east side of the hydrothermal vent field than the core on the west side. While there are a few potential sources of the enrichment, the most likely cause is hydrothermal vent input. Other sources of metal enriched layers include volcanic ash deposits or diagenetic alteration. The findings of this study highlight that hydrothermal vent deposits need to be regarded in the interpretation of paleo-redox and productivity proxies in the ancient rocks deposited near active ocean ridges

Etymological Analyses of the German Christian Theological and Church Loanwords

У статті проведено етимологічний аналіз німецьких християнсько-богословських та церковних термінів-запозичень, виявлено способи їхнього проникнення та мови, які найбільше вплинули на формування німецької християнсько-богословської та церковної термінології. The article deals with etymological analyses of the German Christian theological and church loanwords. It shows the way of its penetration and the languages that mostly influenced the forming of the German Christian theological and church terminology

UNIDADES FRASEOLÓGICAS NA LINGUÍSTICA MODERNA: SISTEMATIZAÇÃO E ANÁLISE SEMÂNTICA

The development of speech culture and communication processes has been influenced significantly by the evolution of communication itself, marked by the incorporation of stable expressions, phrases, and fixed lexical combinations. This transformation has entailed a reevaluation of content and the author's intended message, particularly within the domain of phraseological units. A pivotal area of inquiry within contemporary linguistics involves the assessment of the quality of phraseological unit usage, the delineation of classification approaches, and the formulation of systematization methods tailored to the stylistic and contextual attributes of these linguistic constructs. This article undertakes an examination of the structural components inherent to phraseological units in modern linguistics. Furthermore, it investigates the intricacies of their semantic structure, their contextual utility, and their applications across diverse modes of communication. The article comprehensively considers the intricacies surrounding the evolution of language and the concurrent emergence of new phraseological units. It also addresses the influence of scientific and technological progress, which contributes to the development of novel forms and categories of phraseological units. The distinctiveness in the formation of phraseological units within various language groups can be attributed to a combination of factors, including folk traditions, the written cultural legacy, the creative endeavours of the populace, and the transformation of cultural paradigms. Furthermore, the article emphasizes the significance of systematizing phraseological units, with an emphasis on achieving a qualitative categorization of the most prevalent lexical constructions within the respective language groups under consideration. This article undertakes an in-depth examination of the mechanisms responsible for the generation of phraseological units, as well as the distinctive characteristics in comparing such units across diverse language groups. It also incorporates a comprehensive semantic analysis aimed at elucidating the content and avenues for reinterpretation inherent to phraseological units.O desenvolvimento da cultura da fala e dos processos de comunicação foi influenciado significativamente pela evolução da própria comunicação, marcada pela incorporação de expressões estáveis, frases e combinações lexicais fixas. Esta transformação implicou uma reavaliação do conteúdo e da mensagem pretendida pelo autor, particularmente no domínio das unidades fraseológicas. Uma área central de investigação na linguística contemporânea envolve a avaliação da qualidade do uso de unidades fraseológicas, o delineamento de abordagens de classificação e a formulação de métodos de sistematização adaptados aos atributos estilísticos e contextuais dessas construções linguísticas. Este artigo realiza um exame dos componentes estruturais inerentes às unidades fraseológicas na linguística moderna. Além disso, investiga os meandros da sua estrutura semântica, a sua utilidade contextual e as suas aplicações em diversos modos de comunicação. O artigo considera de forma abrangente as complexidades que cercam a evolução da linguagem e o surgimento simultâneo de novas unidades fraseológicas. Também aborda a influência do progresso científico e tecnológico, que contribui para o desenvolvimento de novas formas e categorias de unidades fraseológicas. A distinção na formação de unidades fraseológicas dentro de vários grupos linguísticos pode ser atribuída a uma combinação de fatores, incluindo tradições folclóricas, o legado cultural escrito, os esforços criativos da população e a transformação de paradigmas culturais. Além disso, o artigo enfatiza a importância da sistematização das unidades fraseológicas, com ênfase na obtenção de uma categorização qualitativa das construções lexicais mais prevalentes nos respectivos grupos linguísticos em consideração. Este artigo realiza um exame aprofundado dos mecanismos responsáveis pela geração de unidades fraseológicas, bem como das características distintivas na comparação de tais unidades em diversos grupos linguísticos. Também incorpora uma análise semântica abrangente que visa elucidar o conteúdo e os caminhos para a reinterpretação inerentes às unidades fraseológicas

Vénás mikroerek vazomotor funkciója hiperhomociszteinémiában = Vasomotor function of venous microvessels in hyperhomocysteinemia

Kutatásaink kiderítették a konstriktor prosztaglandinok döntő szerepét mind a vénás erek mind az agyi erek vasomotor működésében, egészséges és kóros körülmények között. Ez idáig úgy gondolták, hogy a konstriktor prosztaglandinoknak csak kóros szerepe van. A homocystein magas szintje csökkenti a vaszkuláris működést és thrombotikus irányban tereli az endothelium működését, ami felelős lehet a vénás thromboembolitikus elváltozások kialakulásában. Ugyanakkor kimutattuk, hogy a konstriktor prosztaglandinoknak fontos szerepe van az agyi autóreguláció kialakulásában. Feltehető, hogy ezen eredmények elméleti alapot szolgáltatnak új gyógyszertermékek kidolgozásához. | These investigations revealed the important role of constrictor prostaglandins, not only in diseased conditions, but in normal conditions, as well. These results draw the attention again the utmost importance of constrictor prostaglandins in the maintenance of normal and diseased vascular functions, especially to their role in antithrombotic events. In addition, we have shown that constrictor prostaglandins are importantly involved in the modulation of and autoregulation of cerebral circulation, which have not been known previously. These new pathways provide the theoretical basis for the development of new drugs

Post-stroke inhibition of induced NADPH oxidase type 4 prevents oxidative stress and neurodegeneration

Ischemic stroke is the second leading cause of death worldwide. Only one moderately effective therapy exists, albeit with contraindications that exclude 90% of the patients. This medical need contrasts with a high failure rate of more than 1,000 pre-clinical drug candidates for stroke therapies. Thus, there is a need for translatable mechanisms of neuroprotection and more rigid thresholds of relevance in pre-clinical stroke models. One such candidate mechanism is oxidative stress. However, antioxidant approaches have failed in clinical trials, and the significant sources of oxidative stress in stroke are unknown. We here identify NADPH oxidase type 4 (NOX4) as a major source of oxidative stress and an effective therapeutic target in acute stroke. Upon ischemia, NOX4 was induced in human and mouse brain. Mice deficient in NOX4 (Nox4(-/-)) of either sex, but not those deficient for NOX1 or NOX2, were largely protected from oxidative stress, blood-brain-barrier leakage, and neuronal apoptosis, after both transient and permanent cerebral ischemia. This effect was independent of age, as elderly mice were equally protected. Restoration of oxidative stress reversed the stroke-protective phenotype in Nox4(-/-) mice. Application of the only validated low-molecular-weight pharmacological NADPH oxidase inhibitor, VAS2870, several hours after ischemia was as protective as deleting NOX4. The extent of neuroprotection was exceptional, resulting in significantly improved long-term neurological functions and reduced mortality. NOX4 therefore represents a major source of oxidative stress and novel class of drug target for stroke therapy

Mechanisms of Endothelial Dysfunction in Resistance Arteries from Patients with End-Stage Renal Disease

The study focuses on the mechanisms of endothelial dysfunction in the uremic milieu. Subcutaneous resistance arteries from 35 end-stage renal disease (ESRD) patients and 28 matched controls were studied ex-vivo. Basal and receptor-dependent effects of endothelium-derived factors, expression of endothelial NO synthase (eNOS), prerequisites for myoendothelial gap junctions (MEGJ), and associations between endothelium-dependent responses and plasma levels of endothelial dysfunction markers were assessed. The contribution of endothelium-derived hyperpolarizing factor (EDHF) to endothelium-dependent relaxation was impaired in uremic arteries after stimulation with bradykinin, but not acetylcholine, reflecting the agonist-specific differences. Diminished vasodilator influences of the endothelium on basal tone and enhanced plasma levels of asymmetrical dimethyl L-arginine (ADMA) suggest impairment in NO-mediated regulation of uremic arteries. eNOS expression and contribution of MEGJs to EDHF type responses were unaltered. Plasma levels of ADMA were negatively associated with endothelium-dependent responses in uremic arteries. Preserved responses of smooth muscle to pinacidil and NO-donor indicate alterations within the endothelium and tolerance of vasodilator mechanisms to the uremic retention products at the level of smooth muscle. We conclude that both EDHF and NO pathways that control resistance artery tone are impaired in the uremic milieu. For the first time, we validate the alterations in EDHF type responses linked to kinin receptors in ESRD patients. The association between plasma ADMA concentrations and endothelial function in uremic resistance vasculature may have diagnostic and future therapeutic implications