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Quantum control in size selected semiconductor quantum dot thin films
No full textWe introduce a novel technique for coherent control that employs resonant internally generated fields in CdTe quantum dot (QD) thin films at the L-point. The bulk band gap of CdTe at the L-point amounts to 3.6 eV, with the transition marked by strong Coulomb coupling. Third harmonic generation (λ_3 = 343 nm, hν = 3.61 eV) for a fundamental wavelength of λ_1 = 1,030 nm is used to control quantum interference of three-photon resonant paths between the valence and conduction bands. Different thicknesses of the CdTe QDs are used to manipulate the phase relationship between the external fundamental and the internally generated third harmonic, resulting in either suppression or strong enhancement of the resonant third harmonic, while the nonresonant components remain nearly constant. This development could pave the way for new quantum interference–based applications in ultrafast switching of nanophotonic devices
Semen analyses and histological evaluation of male germ cells of healthy aging men
No full textDie Auswirkungen des elterlichen Alters auf die reproduktive Gesundheit gewinnen in alternden Gesellschaften an Bedeutung. Während der Einfluss des mütterlichen Alters gut untersucht ist, bleibt der Einfluss des väterlichen Alters unklar. Um die reinen Effekte des Alterns auf die reproduktive Gesundheit zu erfassen, untersuchte die longitudinale FAMe-Studie ausschließlich gesunde Männer. Die meisten Parameter wie Ejakulatwerte, Hormonspiegel, Hodenvolumen und Marker akzessorischer Geschlechtsdrüsen blieben trotz einzelner Veränderungen im Normbereich, einzig das Prostatavolumen überschritt altersabhängig die Norm. Histologische Analysen von Hodengewebe mit normaler Spermatogenese zeigten weder einen altersbedingten Anstieg von DNA-Doppelstrangbrüchen (γH2AX) noch Veränderungen in den Proteinen SSX2B und PENK. Die Ergebnisse unterstreichen die Widerstandsfähigkeit der männlichen Reproduktionsfunktion und die klinische Kompensation molekularer Alterungsprozesse bei gesunden Männern.The effects of parental age on reproductive health are becoming increasingly important in aging societies. While the impact of maternal age is well studied, the influence of paternal age remains unclear. To assess the pure effects of aging on reproductive health, the longitudinal FAMe study examined exclusively healthy men. Most parameters, including semen values, hormone levels, testicular volume, and markers of accessory sex glands, remained within the normal range despite some slight age-related changes; only prostate volume exceeded the normal range with age. Histological analyses of testicular tissue with normal spermatogenesis showed neither an age-related increase in DNA double-strand breaks (γH2AX) nor changes in the proteins SSX2B and PENK. These findings highlight the resilience of male reproductive function and the clinical compensation of molecular aging processes in healthy men
Thioredoxins m regulate plastid glucose-6-phosphate dehydrogenase activity in Arabidopsis roots under salt stress
No full textPlants contain several NADPH-producing enzymes including glucose-6-phosphate dehydrogenases (G6PDH) with different sub-cellular localizations. The activity of plastidial G6PDHs is redox-regulated by thioredoxins (TRX). Although specific TRXs are known to regulate chloroplastic isoforms of G6PDH, little information is available for plastidic isoforms found in heterotrophic organs or tissues. Here, we investigated TRX regulation of the two G6PDH plastidic isoforms of Arabidopsis roots during exposure to a mild salt stress. We report that 'in vitro' m-type TRXs are the most efficient regulators of the G6PDH2 and G6PDH3 mainly found in Arabidopsis roots. While expression of the corresponding 'G6PD' and plastidic 'TRX' genes was marginally affected by salt, it impaired root growth of several of the corresponding mutant lines. Using an 'in situ' assay for G6PDH, G6PDH2 was found to be the major contributor to salt-induced increases in activity, while data from ROS assays further provide 'in vivo' evidence that TRX m acts in redox regulation during salt stress. Taken together, our data suggest that regulation of plastid G6PDH activity by TRX m may be an important player regulating NADPH production in Arabidopsis roots undergoing salt stress
TRPC1 links calcium signaling to cellular senescence in the protection against posttraumatic osteoarthritis
No full textTransient receptor potential channel 1 (TRPC1) is a widely expressed mechanosensitive ion channel located within the endoplasmic reticulum membrane, crucial for refilling depleted internal calcium stores during activation of calcium-dependent signaling pathways. Here, we have demonstrated that TRPC1 activity is protective within cartilage homeostasis in the prevention of cellular senescence–associated cartilage breakdown during mechanical and inflammatory challenge. We revealed that TRPC1 loss is associated with early stages of osteoarthritis (OA) and plays a nonredundant role in calcium signaling in chondrocytes. Trpc1^–/– mice subjected to destabilization of the medial meniscus–induced OA developed a more severe OA phenotype than WT controls. During early OA development, Trpc1^–/– mice displayed an increased chondrocyte survival rate; however, remaining cells displayed features of senescence including p16^INK4a expression and decreased Sox9. RNA-Seq identified differentially expressed genes related to cell number, apoptosis, and extracellular matrix organization. Trpc1^–/– chondrocytes exhibited accelerated dedifferentiation, while demonstrating an increased susceptibility to cellular senescence. Targeting the mechanism of TRPC1 activation may be a promising therapeutic strategy in OA prevention
Environmental Impacts of Pyro- and Hydrometallurgical Recycling for Lithium-Ion Batteries - A Review
No full textGroup-specific cellular metabolism in Medulloblastoma
No full textBackground: Cancer metabolism influences multiple aspects of tumorigenesis and causes diversity across malignancies. Although comprehensive research has extended our knowledge of molecular subgroups in medulloblastoma (MB), discrete analysis of metabolic heterogeneity is currently lacking. This study seeks to improve our understanding of metabolic phenotypes in MB and their impact on patients’ outcomes. Methods: Data from four independent MB cohorts encompassing 1,288 patients were analysed. We explored metabolic characteristics of 902 patients (ICGC and MAGIC cohorts) on bulk RNA level. Moreover, data from 491 patients (ICGC cohort) were searched for DNA alterations in genes regulating cell metabolism. To determine the role of intratumoral metabolic differences, we examined single-cell RNA-sequencing (scRNA-seq) data from 34 additional patients. Findings on metabolic heterogeneity were correlated to clinical data. Results: Established MB groups exhibit substantial differences in metabolic gene expression. By employing unsupervised analyses, we identified three clusters of group 3 and 4 samples with distinct metabolic features in ICGC and MAGIC cohorts. Analysis of scRNA-seq data confirmed our results of intertumoral heterogeneity underlying the according differences in metabolic gene expression. On DNA level, we discovered clear associations between altered regulatory genes involved in MB development and lipid metabolism. Additionally, we determined the prognostic value of metabolic gene expression in MB and showed that expression of genes involved in metabolism of inositol phosphates and nucleotides correlates with patient survival.
Conclusion: Our research underlines the biological and clinical relevance of metabolic alterations in MB. Thus, distinct metabolic signatures presented here might be the first step towards future metabolism-targeted therapeutic options
Impact of intensified contact precautions while treating hematopoietic stem cell transplantation recipients during aplasia
No full textBackground: Bacterial infections are a major complication for patients undergoing allogeneic hematopoietic stem cell transplantation (HCT). Therefore, protective isolation is considered crucial to prevent nosocomial infections in this population. Here, the impact of intensified contact precautions on environmental contamination and the occurrence of bloodstream infections (BSI) in patients on a HCT unit were compared between two contact precaution measures. Methods: A 2-year retrospective observational study was performed. In the first year, strict contact precaution measures were applied (i.e., protective isolation, the use of sterile personal protective equipment (PPE) by healthcare workers and visitors and sterilization of linen and objects that entered the patient’s room). After one year, contact precautions were reduced (i.e., no use of sterile PPE, no sterilization of linen and objects that entered the patient’s room). Environmental contamination in randomly selected patient rooms was monitored by sampling six standardized environmental sites in the respective patient treatment units. In a before-and-after study, the number of BSI episodes of those patients, who were accommodated in the monitored rooms was compared. Results: In total, 181 treatment units were monitored. No significant difference in the contamination of anterooms and patient’s rooms between both groups was found. A total of 168 patients were followed for the occurrence of BSI during the entire study period (before: 84 patients, after: 84 patients). The total count of patients with BSI episodes showed a higher incidence in the period with reduced contact precautions (30/84 vs. 17/84, p = 0.039). The cause of this increasing number of BSI can be traced back to BSI episodes with common commensal bacteria (17/84 vs. 5/84, p = 0.011). Conclusions: The implementation of maximal barrier measures did not reduce the bacterial contamination of the patients’ environment. The impact on the patients' outcomes remain controversial. Further research is needed to investigate the impact of infection prevention measures on the clinical outcome of patients undergoing HCT
Investing in ETFs - A digital-based modelling task for mathematics lessons
No full textThere is a growing interest in financial education among young people, including many schoolchildren. This is demonstrated in the popularity of YouTube channels such as "Finanzfluss" or "Finanztip" among this target group. At the same time, many school leavers criticise the fact that school does not provide sufficient preparation for personal investment and financial planning. Working on reality-based tasks in mathematics lessons can help to close this gap. For this reason, a digital-based modelling task on the topic of "Investing in ETFs" was developed. The task asks learners to analyse the performance of an ETF using mathematical concepts such as slope triangles, exponential functions and spreadsheets. The task offers the opportunity to address the risks associated with stock market products and to encourage learners to think critically in this context
Severance Payments to Members of Executive Boards without and with Limits
No full textEmpfehlungen zur Beschränkung von Abfindungen an vorzeitig ausscheidende Vorstandsmitglieder werden häufig nicht eingehalten. Solange Vorstandsmitglieder nicht gegen ihren Willen entlassen werden dürfen, ist eine Beschränkung der Abfindungen weder im Interesse der Unternehmen noch effizient. Eine solche Entlassungsmöglichkeit sollte geschaffen werden mit festem Abfindungsanspruch.Recommendations on the limitation of severance payments to board members leaving early are often not followed. As long as board members cannot be dismissed against their will, limiting the severance payments is neither in the interests of the company nor efficient. Such a dismissal option should be created with a fixed entitlement to severance pay
A model of porcine polymicrobial septic shock
No full textBackground: Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. Mortality of patients with sepsis is high and largely unchanged throughout the past decades. Animal models have been widely used for the study of sepsis and septic shock, but translation into effective treatment regimes in the clinic have mostly failed. Pigs are considered as suitable research models for human diseases due to their high comparability and similarity to human anatomy, genetics, and the immune system. We here evaluated the previously reported models of septic shock in pigs and established a novel model of polymicrobial sepsis that meets the clinical criteria of septic shock in pigs.
Materials and methods: The literature search was performed using the keywords “pig”, “sepsis” and “septic shock”. For the establishment of septic shock in n = 10 German landrace pigs, mechanical ventilation was initiated, central venous and arterial lines and invasive hemodynamic monitoring via pulse contour cardiac output measurement (PiCCO) established. Peritoneal polymicrobial faecal sepsis was induced by application of 3 g/kg body weight faeces into the abdominal cavity. Septic shock was defined according to the third international consensus definitions (Sepsis-3). Upon shock, pigs underwent the 1-h bundle for the treatment of human sepsis. Cytokine levels were measured by ELISA.
Results: Published porcine sepsis models exhibited high methodological variability and did not meet the clinical criteria of septic shock. In our model, septic shock developed after an average of 4.8 ± 0.29 h and was associated with a reproducible drop in blood pressure (mean arterial pressure 54 ± 1 mmHg) and significant hyperlactatemia (3.76 ± 0.65 mmol/L). Septic shock was associated with elevated levels of interleukin-6 (IL6) and initial cardiac depression followed by a hyperdynamic phase with significant loss of systemic vascular resistance index after initial resuscitation. In addition, organ dysfunction (acute kidney injury) occurred. Conclusions: We here established a model of septic shock in pigs that meets the clinical criteria of septic shock utilized in human patients. Our model may thus serve as a reference for clinically relevant sepsis research in pigs