A fast, primary Coulomb blockade thermometer

We have measured the third derivative of the current-voltage characteristics, d^3I/dV^3, in a two-dimensional array of small tunnel junctions using a lock-in amplifier. We show that this derivative is zero at a voltage which scales linearly with the temperature and depends only on the temperature and natural constants, thus providing a primary thermometer. We demonstrate a measurement method which extracts the zero crossing voltage directly using a feedback circuit. This method requires only one voltage measurement, which makes it substantially faster than the original Coulomb blockade thermometry method.Comment: 3 pages, 4 figures. This article has been submitted to Applied Physics Letters (http://ojps.aip.org/aplo

Systematic evaluation of agarose- and agar-based bioinks for extrusion-based bioprinting of enzymatically active hydrogels

Extrusion-based 3D bioprinting enables the production of customized hydrogel structures that can be employed in flow reactors when printing with enzyme-containing inks. The present study compares inks based on either low-melt agarose or agar at different concentrations (3–6%) and loaded with the thermostable enzyme esterase 2 from the thermophilic organism Alicyclobacillus acidocaldarius (AaEst2) with regard to their suitability for the fabrication of such enzymatically active hydrogels. A customized printer setup including a heatable nozzle and a cooled substrate was established to allow for clean and reproducible prints. The inks and printed hydrogel samples were characterized using rheological measurements and compression tests. All inks were found to be sufficiently printable to create lattices without overhangs, but printing quality was strongly enhanced at 4.5% polymer or more. The produced hydrogels were characterized regarding mechanical strength and diffusibility. For both properties, a strong correlation with polymer concentration was observed with highly concentrated hydrogels being more stable and less diffusible. Agar hydrogels were found to be more stable and show higher diffusion rates than comparable agarose hydrogels. Enzyme leaching was identified as a major drawback of agar hydrogels, while hardly any leaching from agarose hydrogels was detected. The poor ability of agar hydrogels to permanently immobilize enzymes indicates their limited suitability for their employment in perfused biocatalytic reactors. Batch-based activity assays showed that the enzymatic activity of agar hydrogels was roughly twice as high as the activity of agarose hydrogels which was mostly attributed to the increased amount of enzyme leaching. Agarose bioinks with at least 4.5% polymer were identified as the most suitable of the investigated inks for the printing of biocatalytic reactors with AaEst2. Drawbacks of these inks are limited mechanical and thermal stability, not allowing the operation of a reactor at the optimum temperature of AaEst2 which is above the melting point of the employed low-melt agarose

3D‐Printed Phenacrylate Decarboxylase Flow Reactors for the Chemoenzymatic Synthesis of 4‐Hydroxystilbene

Continuous flow systems for chemical synthesis are becoming a major focus in organic chemistry and there is a growing interest in the integration of biocatalysts due to their high regio‐ and stereoselectivity. Methods established for 3D bioprinting enable the fast and simple production of agarose‐based modules for biocatalytic reactors if thermally stable enzymes are available. We report here on the characterization of four different cofactor‐free phenacrylate decarboxylase enzymes suitable for the production of 4‐vinylphenol and test their applicability for the encapsulation and direct 3D printing of disk‐shaped agarose‐based modules that can be used for compartmentalized flow microreactors. Using the most active and stable phenacrylate decarboxylase from Enterobacter spec. in a setup with four parallel reactors and a subsequent palladium(II) acetate‐catalysed Heck reaction, 4‐hydroxystilbene was synthesized from p‐coumaric acid with a total yield of 14.7 % on a milligram scale. We believe that, due to the convenient direct immobilization of any thermostable enzyme and straightforward tuning of the reaction sequence by stacking of modules with different catalytic activities, this simple process will facilitate the establishment and use of cascade reactions and will therefore be of great advantage for many research approaches

Behandlung komorbider Störungen, Syndrome und Symptome der Posttraumatischen Belastungsstörung nach Missbrauchserfahrungen in der Kindheit mit STAIR-NT. Klinische Empfehlungen und Herausforderungen

Background: Early interpersonal traumatic events, such as childhood maltreatment, increase the risk of developing complex posttraumatic stress symptoms. The biphasic treatment program STAIR-NT (Skills Training for Affective and Interpersonal Regulation with Narrative Therapy), developed specifically for this patient group, combines interventions to improve emotion regulation and interpersonal skills with narrative therapy. Objective: Many affected patients with PTSD after childhood maltreatment also suffer from various comorbid mental disorders and symptoms that can affect and impede the course and outcome of treatment with STAIR-NT. Method: Based on experience from a current treatment study, we provide recommendations for integrating treatment of comorbid mental symptoms into STAIR-NT. Results / Conclusion: Training affective and interpersonal regulation skills in the first treatment phase offers various interventions to efficiently adapt transdiagnostic mechanisms such as emotion dysregulation. In cases of severe comorbid mental disorders or symptoms, adding disorder-specific interventions to STAIR-NT may be indicated.Hintergrund: Frühe interpersonelle traumatische Erfahrungen, wie Misshandlung und Missbrauch in Kindheit und Jugend, erhöhen das Risiko eine komplexe posttraumatische Belastungssymptomatik zu entwickeln. Das zwei-phasische Therapieprogramm STAIR-NT (Skillstraining zur affektiven und interpersonellen Regulation mit narrativer Therapie), das speziell für diese Gruppe von Patient_innen entwickelte wurde, kombiniert Interventionen zur Verbesserung der Emotionsregulation und der interpersonellen Fähigkeiten mit einer narrativen Therapie. Fragestellung: Viele der Betroffenen mit einer PTBS nach Misshandlung und Missbrauch in der Kindheit leiden unter einer Vielzahl komorbider psychischer Symptome, die den Verlauf und das Ergebnis der Behandlung mit STAIR-NT beeinflussen und behindern können. Methode: Basierend auf den Erfahrungen aus einer aktuellen Therapiestudie werden hier Empfehlungen für die Integration der Behandlung komorbider psychischer Symptomatik in STAIR-NT gegeben. Ergebnis / Schlussfolgerung: Vor allem das Training affektiver und interpersoneller Regulationsfähigkeiten in der ersten Therapiephase bietet vielfältige Interventionen zur Veränderung störungsübergreifender Mechanismen wie Emotionsdysregulation. Bei besonders schwerwiegender komorbider Symptomatik kann die zusätzliche Anwendung von störungsspezifischen Interventionen zur STAIR-NT indiziert sein

Böden und gentechnisch veränderter Mais (Bt-Mais) Teil I - Quantifizierung der Sorption von Cry3Bb1 an Bodenfraktionen einer Freisetzungsfläche

Die Sorption des Cry3Bb1 Proteins aus Bt-Mais an drei Größenfraktionen der Böden einer Freisetzungsfläche und der Einfluss von pH-Wert und Ionenstärke auf die Sorption von Cry3Bb1 wurden untersucht. Die Ergebnisse zeigen eine deutliche Abhängigkeit der Sorption von der Partikelgröße. Der pH-Werte zeigte einen unklaren Einfluss, während die Sorption in Anwesenheit von Calcium in der Hintergrundlösung stark zunahm

Böden und gentechnisch veränderter Mais (Bt-Mais)- Teil II - Effekt der physico-chemischen Parameter der Böden auf die Retardation von Cry3Bb1

Während der Vegetationsperiode gelangen Bt-Proteine, die in gentechnisch verändertem Mais (Bt-Mais) exprimiert werden, sowohl über Erntereste als auch über Polleneintrag und Wurzelexsudate in die Böden und werden dort an Bodenpartikeln sorbiert. Vor dem Hintergrund, dass Bt-Mais zunehmend angebaut wird, erfolgten Untersuchungen zur Sorption des Proteins Cry3Bb1 unter anderem an Proben der Tonfraktionen einer Freisetzungsfläche, auf der Bt-Mais angebaut wurde (siehe „Böden und gentechnisch veränderter Mais (Bt-Mais) - Teil I“). Der Mechanismus der Cry3Bb1-Sorption muss zudem näher erfasst werden, um letztendlich Informationen über die Verfügbarkeit der Bt-Proteine zu erhalten. Daher wurden die Böden der Freisetzungsfläche zusätzlich auf ihre oberflächenchemischen und chemisch-mineralogischen Eigenschaften hin-reichend untersucht. In Zusammenarbeit mit dem Institut für Biostatistik der Leibniz Universität Hannover (Frank Schaarschmidt) wurden diese gewonnenen Daten mit den jeweiligen Verteilungs-koeffizienten (k), die mathematisch aus der linearen Sorptionsisotherme berechnet wurden, in Beziehung gebracht und statistisch ausgewertet. Anhand eines Scatterplots wurde der Zusammenhang zwischen k und den jeweiligen bodenkundlichen Parametern der Tonfraktion dargestellt. Zwischen k und dem Corg-Gehalt der Tonfraktion des Oberbodens wurde ein positiver Zusam-menhang festgestellt. Dahingegen zeigte die Tonfraktion des Unterbodens mit abnehmendem Corg-Gehalt eine höhere Affinität zu Cry3Bb1, was den Ergebnissen zur Cry1Ab-Sorption entspricht (Pagel-Wieder et al., 2004, 2007)

Biological Reconstruction of Localized Full-Thickness Cartilage Defects of the Knee: A Systematic Review of Level 1 Studies with a Minimum Follow-Up of 5 Years

Objective The objective of this study was to evaluate the best available mid- to long-term evidence of surgical procedures for the treatment of localized full-thickness cartilage defects of the knee. Design Systematic review using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines of Level 1 randomized clinical trials (RCTs), meta-analyses of RCTs and systematic reviews with a minimum follow-up of 5 years. Data extracted included patient demographics, defect characteristics, clinical and radiological outcomes, as well as treatment failures. Results Six RCTs and 3 Level 1 systematic reviews were included. Two RCTs compared microfracture (MFx) to periosteum-covered autologous chondrocyte implantation (ACI-P), 1 to matrix-associated ACI (M-ACI) and 2 to osteochondral autograft transplantation (OAT). One study compared OAT to collagen membrane covered ACI (ACI-C). The 3 Level 1 systematic reviews/meta-analyses assessed the outcome of MFx, OAT, and various ACI methods in RCTs. OAT showed significantly better outcomes compared with MFx. In the 2 RCTs comparing ACI-P and MFx, no significant differences in clinical outcomes were seen, whereas significantly better outcomes were reported for M-ACI versus MFx in 1 study including patients with larger defects (5 cm2), and for ACI-C versus OAT in terms of Cincinnati Score. Higher failure rates were reported for MFx compared with OAT and for OAT compared with ACI-C, while no significant differences in failure rates were observed for ACI-P compared to MFx. Conclusion Restorative cartilage procedures (ACI-C or M-ACI and OAT) are associated with better long-term clinical outcomes including lower complication and failure rates when compared with reparative techniques (MFx). Among the restorative procedures, OAT seems to be inferior to ACI especially in larger defects after longer follow-up periods. Level of evidence: Level I: Systematic review of Level I studie

The SARS-coronavirus-host interactome

Coronaviruses (CoVs) are important human and animal pathogens that induce fatal respiratory, gastrointestinal and neurological disease. The outbreak of the severe acute respiratory syndrome (SARS) in 2002/2003 has demonstrated human vulnerability to (Coronavirus) CoV epidemics. Neither vaccines nor therapeutics are available against human and animal CoVs. Knowledge of host cell proteins that take part in pivotal virus-host interactions could define broad-spectrum antiviral targets. In this study, we used a systems biology approach employing a genome-wide yeast-two hybrid interaction screen to identify immunopilins (PPIA, PPIB, PPIH, PPIG, FKBP1A, FKBP1B) as interaction partners of the CoV non-structural protein 1 (Nsp1). These molecules modulate the Calcineurin/NFAT pathway that plays an important role in immune cell activation. Overexpression of NSP1 and infection with live SARS-CoV strongly increased signalling through the Calcineurin/NFAT pathway and enhanced the induction of interleukin 2, compatible with late-stage immunopathogenicity and long-term cytokine dysregulation as observed in severe SARS cases. Conversely, inhibition of cyclophilins by cyclosporine A (CspA) blocked the replication of CoVs of all genera, including SARS-CoV, human CoV-229E and -NL-63, feline CoV, as well as avian infectious bronchitis virus. Non-immunosuppressive derivatives of CspA might serve as broad-range CoV inhibitors applicable against emerging CoVs as well as ubiquitous pathogens of humans and livestock