Thermal stability of glued wood joints measured by shear tests

The thermal stability of glued wood joints is an important criterion to determine the suitability of adhesives in the field of engineered wood. During their product life, glued wood joints can be exposed to high temperatures in various ways (direct exposure to the sun, fire, etc.). Thereby the cohesiveness of the adhesive must not degrade. This raises the question of how the strength of bonding changes under thermal load. The current investigation covers the influence of temperature (T=20 to 220°C) on the shear strength of glued wood joints. Different adhesive systems were investigated. With increasing temperature, the shear strength of solid wood and also of glued wood joints decreased. There were big differences in thermal stability and failure behaviour between the adhesive systems as well as within the polyurethane group. The thermal stability of one-component polyurethane systems can be greatly varied by modifying their chemical structure. Well adapted one-component polyurethane adhesives reach a strength similar to that of phenol resorcinol resi

The epidemiology of uveal melanoma in Germany: a nationwide report of incidence and survival between 2009 and 2015

Purpose: To calculate the overall incidence of uveal melanoma in Germany and to compare incidences in different German states. In addition, we computed the overall and cancer-specific survival rates nationwide. Methods: Incidence data for the period between 2009 and 2015, covering the entire German population, was collected through the German Center for Cancer Registry. ICD-O-3 topography codes C69.3-C69.4 and histology codes for melanoma subtypes were used to collect the incidence data. Confidence Intervals with a level of 95% (95% CI) were calculated for rates. Survival was calculated using the Kaplan–Meier. The log-rank test was used for survival comparisons. Results: This study comprised 3654 patients with uveal melanomas, including 467 (12.8%) with iridial and ciliary body tumors. The overall age-standardized incidence rate (ASIR) was 6.41 person per million. Generally, the ASIR was higher in males than females (6.67 (95% CI 6.37–6.98) vs. 6.16 (95% CI 5.88–6.45 per million). Higher crude incidence rates were noted in the northeastern states (12.5 per million (95% CI 10.5–14.7) in Mecklenburg-Vorpommern) compared with the southwestern states (2.1 per million (95% CI 1.7–2.6) in Hessen). The 5-year overall survival stood at 47%, while the cancer-specific survival stood at 84%. Multivariate analysis showed that women, younger patients, and patients living in Berlin achieved significantly higher overall survival. Conclusion: Overall ASIR of uveal melanoma in Germany indicates that the disease is more common in males and that it follows the same geographical distribution previously noted in central European countries, with the highest incidence in northern parts of Germany

An Algorithmic View on OVSF Code Assignment

Orthogonal Variable Spreading Factor (OVSF) codes are used in UMTS to share the radio spectrum among several connections of possibly different bandwidth requirements. The combinatorial core of the OVSF code assignment problem is to assign some nodes of a complete binary tree of height h (the code tree) to n simultaneous connections, such that no two assigned nodes (codes) are on the same root-to-leaf path. A connection that uses a 2-d fraction of the total bandwidth requires some code at depth d in the tree, but this code assignment is allowed to change over time. Requests for connections that would exceed the total available bandwidth are rejected. We consider the one-step code assignment problem: Given an assignment, move the minimum number of codes to serve a new request. Minn and Siu propose the so-called DCA algorithm to solve the problem optimally. In contrast, we show that DCA does not always return an optimal solution, and that the problem is NP-hard. We give an exact nO(h)-time algorithm, and a polynomial-time greedy algorithm that achieves approximation ratio Θ(h). A more practically relevant version is the online code assignment problem, where future requests are not known in advance. Our objective is to minimize the overall number of code reassignments. We present a Θ(h)-competitive online algorithm, and show that no deterministic online algorithm can achieve a competitive ratio better than 1.5. We show that the greedy strategy (minimizing the number of reassignments in every step) is not better than Ω(h) competitive. We give a 2-resource augmented online algorithm that achieves an amortized constant number of (re-)assignments. Finally, we show that the problem is fixed-parameter tractabl

On competition and transparency in public procurement during the COVID-19 pandemic in the European Union

Government expenditures on acquiring services, goods, and work through public procurement represent a substantial proportion of the EU’s GDP. Competitive and transparent tendering procedures are generally believed to promote achieving the primary goals of public procurement: maximising value for money and reducing corruption. However, during the crisis, procurement rules allow a temporary departure from transparency standards toward fast and more discretionary procurement procedures justified by force majeure, possibly restricting competitiveness and information availability in the whole procurement process. The presented paper examines emergency response procurement measures by EU countries in the aftermath of the COVID-19 outbreak in the spring of 2020 and their impact on competition. Using an extensive dataset of contracts for medical supplies and PPE obtained from Tenders Electronic Daily, we document the rapid increase of direct and negotiated contracts in the first two months of the pandemic outbreak. We found that firms, in general, were more likely to participate in procurement procedures with a prior call for tenders, such as open procedure and restricted procedure. On the other hand, the significant share of contracts obtained by small and medium enterprises without competition, hence by single bid procurement, suggests that public authorities tend to use their discretion in favour of SMEs. Moreover, overall emergency procurement setting and its effects on competition vary across countries regardless of how intensely the pandemic hit, indicating an institutional context for the increased discretion effects on procurement outcome

Analysis of 39 drugs and metabolites, including 8 glucuronide conjugates, in an upstream wastewater network via HPLC-MS/MS

© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Foppe, K. S., Kujawinski, E. B., Duvallet, C., Endo, N., Erickson, T. B., Chai, P. R., & Matus, M. Analysis of 39 drugs and metabolites, including 8 glucuronide conjugates, in an upstream wastewater network via HPLC-MS/MS. Journal of Chromatography B, 1176, (2021): 122747, https://doi.org/10.1016/j.jchromb.2021.122747.Pharmaceutical compounds ingested by humans are metabolized and excreted in urine and feces. These metabolites can be quantified in wastewater networks using wastewater-based epidemiology (WBE) methods. Standard WBE methods focus on samples collected at wastewater treatment plants (WWTPs). However, these methods do not capture more labile classes of metabolites such as glucuronide conjugates, products of the major phase II metabolic pathway for drug elimination. By shifting sample collection more upstream, these unambiguous markers of human exposure are captured before hydrolysis in the wastewater network. In this paper, we present an HPLC-MS/MS method that quantifies 8 glucuronide conjugates in addition to 31 parent and other metabolites of prescription and synthetic opioids, overdose treatment drugs, illicit drugs, and population markers. Calibration curves for all analytes are linear (r2 > 0.98), except THC (r2 = 0.97), and in the targeted range (0.1–1,000 ng mL−1) with lower limits of quantification (S/N = 9) ranging from 0.098 to 48.75 ng mL−1. This method is fast with an injection-to-injection time of 7.5 min. We demonstrate the application of the method to five wastewater samples collected from a manhole in a city in eastern Massachusetts. Collected wastewater samples were filtered and extracted via solid-phase extraction (SPE). The SPE cartridges are eluted and concentrated in the laboratory via nitrogen-drying. The method and case study presented here demonstrate the potential and application of expanding WBE to monitoring labile metabolites in upstream wastewaterThis work was supported by the National Institute on Drug Abuse of the National Institutes of Health award number R44DA051106 to MM and PC. TE, PC and MM are funded by research grants from the Massachusetts Consortium on Pathogen Readiness and NIH R44DA051106. PRC is funded by NIH K23DA044874, independent research grants from e-ink corporation and Hans and Mavis Lopater Psychosocial Foundation

Oxidation and Release of Ruthenium from Short Fuel Rods above 1500oC

The fission product ruthenium is radiotoxic and in oxidized form as ruthenium-tetroxide (RuO4) also chemical toxic. During fuel element change or in case of a leakage in fuel storages, air flows in the containment or fuel storage. If the circulation pump fails, the fuel elements are heated-up, and at high temperatures gaseous ruthenium oxides are formed and rapidly released from the fuel. Due to the significant higher volatility of RuO4 in the Chernobyl Catastrophe the measured concentration of the Ru-isotopes in the fall-outs was comparable to those of iodine and caesium. In order to get more insight in the chemical and physical behaviour of this fission product under severe accident conditions, the Ruthenium release was studied in a series of Separate Effect Tests (RUSET). In the test short fuel rod segments were used and exposed to air and steam atmosphere at high temperatures. The experiments in air atmosphere showed, that the partial pressures of the released Ru-oxides was two orders of magnitudes lower compared to those measured in previous tests with Ru-powder diluted in a ZrO2 matrix. It was found that ruthenium was not released in steam atmosphere in the examined temperature range. Furthermore, the temperature dependence of the deposition was detected by XRF analysis.JRC.F.4-Nuclear design safet

Optimized unconventional superconductivity in a molecular Jahn-Teller metal

Understanding the relationship between the superconducting, the neighboring insulating, and the normal metallic state above Tc is a major challenge for all unconventional superconductors. The molecular A3C60 fulleride superconductors have a parent antiferromagnetic insulator in common with the atom-based cuprates, but here, the C603– electronic structure controls the geometry and spin state of the structural building unit via the on-molecule Jahn-Teller effect. We identify the Jahn-Teller metal as a fluctuating microscopically heterogeneous coexistence of both localized Jahn-Teller–active and itinerant electrons that connects the insulating and superconducting states of fullerides. The balance between these molecular and extended lattice features of the electrons at the Fermi level gives a dome-shaped variation of Tc with interfulleride separation, demonstrating molecular electronic structure control of superconductivity

Cardiac connexin-43 hemichannels and pannexin1 channels: Provocative antiarrhythmic targets

Cardiac connexin-43 (Cx43) creates gap junction channels (GJCs) at intercellular contacts and hemi-channels (HCs) at the peri-junctional plasma membrane and sarcolemmal caveolae/rafts compartments. GJCs are fundamental for the direct cardiac cell-to-cell transmission of electrical and molecular signals which ensures synchronous myocardial contraction. The HCs and structurally similar pannexin1 (Panx1) channels are active in stressful conditions. These channels are essential for paracrine and autocrine communication through the release of ions and signaling molecules to the extracellular environment, or for uptake from it. The HCs and Panx1 channel-opening profoundly affects intracellular ionic homeostasis and redox status and facilitates via purinergic signaling pro-inflammatory and pro-fibrotic processes. These conditions promote cardiac arrhythmogenesis due to the impairment of the GJCs and selective ion channel function. Crosstalk between GJCs and HCs/Panx1 channels could be crucial in the development of arrhythmogenic substrates, including fibrosis. Despite the knowledge gap in the regulation of these channels, current evidence indicates that HCs and Panx1 channel activation can enhance the risk of cardiac arrhythmias. It is extremely challenging to target HCs and Panx1 channels by inhibitory agents to hamper development of cardiac rhythm disorders. Progress in this field may contribute to novel therapeutic approaches for patients prone to develop atrial or ventricular fibrillation.Fil: Andelova, Katarina. Slovak Academy of Sciences. Institute for Heart Research; EslovaquiaFil: Benova, Tamara Egan. Slovak Academy of Sciences. Institute for Heart Research; EslovaquiaFil: Bacova, Barbara Szeiffova. Slovak Academy of Sciences. Institute for Heart Research; EslovaquiaFil: Sykora, Matus. Slovak Academy of Sciences. Institute for Heart Research; EslovaquiaFil: Prado, Natalia Jorgelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Diez, Emiliano Raúl. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Hlivak, Peter. National Institute Of Cardiovascular Diseases; EslovaquiaFil: Tribulova, Narcis. Slovak Academy of Sciences. Institute for Heart Research; Eslovaqui

Prognostic Factors in Patients with Persistent Full-Thickness Idiopathic Macular Holes Treated with Re-Vitrectomy with Autologous Platelet Concentrate

Purpose: To identify the predictors for anatomical and functional outcome after re-vitrectomy with application of autologous platelet concentrate (APC) in eyes with persistent idiopathic macular hole (MH). Methods: Retrospective study of 103 eyes with persistent MHs after vitrectomy with peeling of internal limiting membrane (ILM) and expansive gas. All patients underwent re-vitrectomy with APC and endotamponade. The anatomical MH closure rate and postoperative best-corrected visual acuity (BCVA) were evaluated. Further, predictive factors influencing the success of the surgery were analyzed. Results: Median BCVA (logMAR) before the surgery was 1.00 (interquartile range [IQR] 0.80–1.30) and the median of minimum diameter between hole edges was 508 μm (IQR 387–631). The final closure rate after re-vitrectomy with APC was 60.2% (62 of 103 eyes). The following predictors were identified to significantly influence the closure rate: tractional hole index (THI), axial length, time between first and second surgery, and the experience of the surgeon (p < 0.05). Conclusions: Re-vitrectomy with APC led to the closure of 60.2% of the persistent MHs. The closure rate negatively correlates with increasing axial length, time between the first and second surgery, and the decreased THI. Further, experienced surgeons (with a history of > 100 pars plana vitrectomies with ILM peeling) had significantly higher closure rates