134 research outputs found
Self-Assembled Fluorescent Block Copolymer Micelles with Responsive Emission
Responsive fluorescent materials offer a high potential for sensing and (bio‐)imaging applications. To investigate new concepts for such materials and to broaden their applicability, the previously reported non‐fluorescent zinc(II) complex [Zn(L)] that shows coordination‐induced turn‐on emission was encapsulated into a family of non‐fluorescent polystyrene‐block‐poly(4‐vinylpyridine) (PS‐b‐P4VP) diblock copolymer micelles leading to brightly emissive materials. Coordination‐induced turn‐on emission upon incorporation and ligation of the [Zn(L)] in the P4VP core outperform parent [Zn(L)] in pyridine solution with respect to lifetimes, quantum yields, and temperature resistance. The quantum yield can be easily tuned by tailoring the selectivity of the employed solvent or solvent mixture and, thus, the tendency of the PS‐b‐P4VP diblock copolymers to self‐assemble into micelles. A medium‐dependent off–on sensor upon micelle formation could be established by suppression of non‐micelle‐borne emission background pertinent to chloroform through controlled acidification indicating an additional pH‐dependent process
Magnetic NiFe₂O₄ Nanoparticles Prepared via Non-Aqueous Microwave-Assisted Synthesis for Application in Electrocatalytic Water Oxidation
Phase‐pure spinel‐type magnetic nickel ferrite (NiFe(2)O(4)) nanocrystals in the size range of 4 to 11 nm were successfully synthesized by a fast and energy‐saving microwave‐assisted approach. Size and accessible surface areas can be tuned precisely by the reaction parameters. Our results highlight the correlation between size, degree of inversion, and magnetic characteristics of NiFe(2)O(4) nanoparticles, which enables fine‐tuning of these parameters for a particular application without changing the elemental composition. Moreover, the application potential of the synthesized powders for the electrocatalytic oxygen evolution reaction in alkaline media was demonstrated, showing that a low degree of inversion is beneficial for the overall performance. The most active sample reaches an overpotential of 380 mV for water oxidation at 10 mA cm(−2) and 38.8 mA cm(−2) at 1.7 V vs. RHE, combined with a low Tafel slope of 63 mV dec(−1)
BKV, CMV, and EBV Interactions and their Effect on Graft Function One Year Post-Renal Transplantation: Results from a Large Multi-Centre Study
Background
BK virus (BKV), Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) reactivations are common after kidney transplantation and associated with increased morbidity and mortality. Although CMV might be a risk factor for BKV and EBV, the effects of combined reactivations remain unknown. The purpose of this study is to ascertain the interaction and effects on graft function of these reactivations.
Methods
3715 serum samples from 540 kidney transplant recipients were analysed for viral load by qPCR. Measurements were performed throughout eight visits during the first post-transplantation year. Clinical characteristics, including graft function (GFR), were collected in parallel.
Findings
BKV had the highest prevalence and viral loads. BKV or CMV viral loads over 10,000 copies·mL−1 led to significant GFR impairment. 57 patients had BKV-CMV combined reactivation, both reactivations were significantly associated (p = 0.005). Combined reactivation was associated with a significant GFR reduction one year post-transplantation of 11.7 mL·min−1·1.73 m−2 (p = 0.02) at relatively low thresholds (BKV > 1000 and CMV > 4000 copies·mL−1). For EBV, a significant association was found with CMV reactivation (p = 0.02), but no GFR reduction was found. Long cold ischaemia times were a further risk factor for high CMV load.
Interpretation
BKV-CMV combined reactivation has a deep impact on renal function one year post-transplantation and therefore most likely on long-term allograft function, even at low viral loads. Frequent viral monitoring and subsequent interventions for low BKV and/or CMV viraemia levels and/or long cold ischaemia time are recommended.
Fund
Investigator Initiated Trial; financial support by German Federal Ministry of Education and Research (BMBF).Peer Reviewe
Sex-Associated Differences in Cytomegalovirus Prevention: Prophylactic Strategy is Potentially Associated With a Strong Kidney Function Impairment in Female Renal Transplant Patients
Post-transplantation cytomegalovirus (CMV) syndrome can be prevented using the antiviral drug (val)ganciclovir. (Val)ganciclovir is typically administered following a prophylactic or a pre-emptive strategy. The prophylactic strategy entails early universal administration, the pre-emptive strategy, early treatment in case of infection. However, it is not clear which strategy is superior with respect to transplantation outcome; sex-specific effects of these prevention strategies are not known. We have retrospectively analyzed 540 patients from the multi-centre Harmony study along eight pre-defined visits: 308 were treated according to a prophylactic, 232 according to a pre-emptive strategy. As expected, we observed an association of prophylactic strategy with lower incidence of CMV syndrome, delayed onset and lower viral loads compared to the pre-emptive strategy. However, in female patients, the prophylactic strategy was associated with a strong impairment of glomerular filtration rate one year post-transplant (difference: -11.8 ± 4.3 ml min-1·1.73 m-2, p = 0.006). Additionally, we observed a tendency of higher incidence of acute rejection and severe BK virus reactivation in the prophylactic strategy group. While the prophylactic strategy was more effective for preventing CMV syndrome, our results suggest for the first time that the prophylactic strategy might lead to inferior transplantation outcomes in female patients, providing evidence for a strong association with sex. Further randomized controlled studies are necessary to confirm this potential negative effect
Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences
The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported
by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on
18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based
researchers who signed it in the short time span from 20 September to 6 October 2016
Risk factors for Epstein–Barr virus reactivation after renal transplantation: Results of a large, multi‐centre study
Epstein-Barr virus (EBV) reactivation is a very common and potentially lethal complication of renal transplantation. However, its risk factors and effects on transplant outcome are not well known. Here, we have analysed a large, multi-centre cohort (N = 512) in which 18.4% of the patients experienced EBV reactivation during the first post-transplant year. The patients were characterized pre-transplant and two weeks post-transplant by a multi-level biomarker panel. EBV reactivation was episodic for most patients, only 12 patients showed prolonged viraemia for over four months. Pre-transplant EBV shedding and male sex were associated with significantly increased incidence of post-transplant EBV reactivation. Importantly, we also identified a significant association of post-transplant EBV with acute rejection and with decreased haemoglobin levels. No further severe complications associated with EBV, either episodic or chronic, could be detected. Our data suggest that despite relatively frequent EBV reactivation, it had no association with serious complications during the first post-transplantation year. EBV shedding prior to transplantation could be employed as biomarkers for personalized immunosuppressive therapy. In summary, our results support the employed immunosuppressive regimes as relatively safe with regard to EBV. However, long-term studies are paramount to support these conclusions
Transformation des Energiesystems: Chancen des Ausbaus von Windenergie- und Photovoltaikanlagen für ländliche Räume nutzen ; Stellungnahme des Sachverständigenrats Ländliche Entwicklung (SRLE) beim Bundesministerium für Ernährung und Landwirtschaft (BMEL)
Demokratiestärkung in ländlichen Räumen vor dem Hintergrund rechtsextremistischer Demokratiegefährdung : Stellungnahme des Sachverständigenrats Ländliche Entwicklung (SRLE) beim Bundesministerium für Ernährung und Landwirtschaft (BMEL)
Nicht nur in Deutschland, sondern in ganz Europa und weltweit zeigen sich eine sinkende Zufriedenheit mit dem erlebten System Demokratie und ein Erstarken rechtsextremer Kräfte. In Teilen der Bevölkerung erodiert das Vertrauen in die politischen Repräsentant*innen und die Demokratie. Die staatliche Handlungsfähigkeit wird infrage gestellt. Auch das Vertrauen in den gesellschaftlichen Zusammenhalt schwindet seit geraumer Zeit. In Deutschland zeigte sich dies unter anderen an den stark gestiegenen Stimmenanteilen der AfD bei Kommunal-, Landtags- und Bundestagswahlen und deren zunehmender Radikalisierung. Die Europawahl 2024 spiegelt diese Entwicklung deutlich wider. Vor diesem Hintergrund und weiteren demokratiegefährdenden Entwicklungen begrüßt der Sachverständigenrat Ländliche Entwicklung ausdrücklich die im Mai 2024 verabschiedete „Strategie der Bundesregierung für eine starke, wehrhafte Demokratie und eine offene und vielfältige Gesellschaft“ (BMI 2024) und die darin vorgesehenen Maßnahmen. Die vorliegende Stellungnahme des SRLE zur Demokratiestärkung fokussiert auf die Demokratiegefährdung durch Rechtspopulismus/Rechtsextremismus, da Rechtsextremismus und Rechtsterrorismus laut BMI (2024) weiterhin die größte Bedrohung für das demokratische Gemeinwesen in Deutschland darstellen. Sie fokussiert zudem auf ländliche Räume und ergänzt damit die in der Demokratiestrategie der Bundesregierung aufgeführten Darlegungen. Der SRLE spricht folgende Empfehlungen für Bund, Länder und Kommunen aus: • Demokratiestrategie der Bundesregierung zügig und beständig umsetzen • Gleichwertige Lebensverhältnisse – ländliche Räume stärker in den Blick der Politik nehmen • Vertrauen in staatliche Institutionen stärken o Kommunale Handlungsfähigkeit verbessern o Gesetzgebung und Umsetzbarkeit verbessern • Zusammenhalt stärken – Gestaltungsprozesse vor Ort ausbauen • Geschlechtergerechtigkeit in der Politik fördern • Kinder-, Jugend- und Bildungsarbeit zur Demokratiestärkung ausbauen • Forschung zu raumwirksamen Bestimmungsfaktoren für rechtsextreme Einstellungen und Wahlpräferenzen ausbauen Die Empfehlungen des SRLE richten sich an die politischen Akteur*innen aller staatlichen Ebenen. Der SRLE ist sich aber bewusst, dass unser aller Handeln gefordert ist. Um es mit den Worten von Bundespräsident Frank-Walter Steinmeier in seiner Rede vom 21.01.2024 zu sagen: „Die Zukunft unserer Demokratie hängt nicht von der Lautstärke ihrer Gegner ab – sondern von der Stärke derer, die die Demokratie verteidigen.
Predictors of gallstone composition in 1025 symptomatic gallstones from Northern Germany
BACKGROUND: Gallstones represent a prevalent and costly health problem. The changing epidemiology and the emerging non-surgical interventions for gallstone disease necessitate the definition of target populations for future therapies. This study aimed to define patterns of gallstone composition and identify demographic predictors of gallstone composition in a large sample of symptomatic gallstones from Northern Germany. METHODS: One thousand and seventy-four post-cholecystectomy gallstone specimens were obtained. Demographic and clinical information was provided by questionnaire (N = 1025 independent individuals with complete information). Two samples from each gallstone were analyzed using Fourier transformed infrared spectrometry. RESULTS: The most prevalent substance was cholesterol, which was detected in 95.0% of gallstone specimens. Bilirubin and bilirubinate were present in 30.0% and calcium was detected in 10.0% of the spectra. Ninety-two percent of measurements from the same stone yielded the same "main" substances, indicating a homogenous stone composition in most cases. Female sex and higher body mass index (BMI) were associated with the presence of cholesterol as a main substance in the gallstones (p < 0.001). CONCLUSION: The changing epidemiology of gallstone disease is reflected by a marked shift in stone composition: Only two percent of stones in this study were pigment stones as compared to 91% percent of stones containing cholesterol as a main substance. Obese individuals from Germany with a BMI > 30 kg/m(2 )have in 95% cholesterol-dominant gallstones and represent a potential target population for non-surgical interventions for the prevention or treatment of cholesterol stones
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