Search

Graphdiyne polymers have interesting electronic properties due to their π-conjugated structure and modular composition. Most of the known synthetic pathways for graphdiyne polymers yield amorphous solids because the irreversible formation of carbon–carbon bonds proceeds under kinetic control and because of defects introduced by the inherent chemical lability of terminal alkyne bonds in the monomers. Here, we present a one-pot surface-assisted deprotection/polymerisation protocol for the synthesis of crystalline graphdiynes over a copper surface starting with stable trimethylsilylated alkyne monomers. In comparison to conventional polymerisation protocols, our method yields large-area crystalline thin graphdiyne films and, at the same time, minimises detrimental effects on the monomers like oxidation or cyclotrimerisation side reactions typically associated with terminal alkynes. A detailed study of the reaction mechanism reveals that the deprotection and polymerisation of the monomer is promoted by Cu(ii) oxide/hydroxide species on the as-received copper surface. These findings pave the way for the scalable synthesis of crystalline graphdiyne-based materials as cohesive thin films., We present a one-pot deprotection/polymerisation protocol for the synthesis of crystalline graphdiynes on top of a copper surface starting with stable trimethylsilylated alkyne monomers.

We report on the temperature-dependent operation of fluorite-structure-based ferroelectric FET (FeFET) emerging memory. A temperature range (− 40 °C to 40 °C) is used to explore the FeFET characteristic relation to operating temperature. The memory window (MW) shows a modulated response that features a reciprocal MW dependence on temperature, such that a maximum of the MW is realized at − 40 °C. The gradual MW closure upon temperature increase is attributed to the ferroelectric (FE) polarization change with temperature. On the contrary, the FE coercive field shows a minor variation with operating temperature. The FeFET state readout shows a trend of ${V}_{\text {th}}$ shift with temperature such that the decrease in remnant polarization, as well as the substrate effects, causes a maximized shift for erase (ER) state compared to the program (PG) one. The benchmark of Si-doped hafnium oxide (HSO) and hafnium zirconium oxide (HZO) shows comparable trends for dependence on temperature. The temperature cycling by repetitive sweep from − 40 °C to 40 °C shows reproducible MW and PG/ER readout trends with a predictable FeFET response over temperature. This suggests system design techniques for mitigating the variation effects. The FeFET characteristics are explored with insight on physical mechanisms and FE response to temperature variation.

We thank the German Science Foundation (DFG) for financial support within the grants SFB 765 and SFB 658. M.F.G. and J.P.R. also acknowledge the support of the Cluster of Excellence “Matters of Activity. Image Space Material” funded by the DFG under Germany’s Excellence Strategy EXC 2025-390648296. Furthermore, A.T. acknowledges the DFG for funding within the project TH 1463/12-1. We thank Dr. Andreas Schäfer and Maiko Schulze for solid NMR experiments and we appreciate the effort of Vahid Ahmadi Soureshjani in MALDI-TOF experiments. We acknowledge M. Eng. Jörg M. Stockmann for operating the XPS instrument at the BAM and Prof. Stephanie Reich and Dr. Antonio Setaro for fruitful discussions. 2DTs-HRTEM and -EELS studies were conducted at the Laboratorio de Microscopias Avanzadas, Instituto de Nanociencia de Aragon, Universidad de Zaragoza, Spain. R.A. gratefully acknowledges the support from the Spanish Ministry of Economy and Competitiveness (MINECO) through project grant MAT2016-79776-P (AEI/FEDER, UE) and from the European Union H2020 programs ETN projects “Graphene Flagship” (785219 and 881603), FLAG-ERA - Graphene (MICINN) GATES (PCI2018-093137) and “ESTEEM3” (823717).

Crystalline semiconducting carbon nitrides are chemically and physically resilient, consist of earth abundant elements, and can be exfoliated into 2D atomically thin layers. In particular, poly(triazine imide) (PTI) is a highly crystalline semiconductor, and though no techniques exist to date that enable synthesis of macroscopic monolayers of PTI, it is possible to study it in thin layer device applications that are compatible with its polycrystalline, nanoscale morphology. In our study, we find that the by-product of conventional PTI synthesis is a C-C carbon rich phase that is detrimental for charge transport and photoluminescence. An optimised synthetic protocol yields a PTI material with an increased quantum yield, enabled photocurrent and electroluminescence. In addition, we report that protonation of the PTI structure happens preferentially at the pyridinic nitrogen atoms of the triazine (C 3 N 3 ) rings, is accompanied by exfoliation of PTI layers, and contributes to increases in quantum yield and exciton lifetimes. This study describes structure-property relationships in PTI that link (i) the nature of defects, their formation, and how to avoid them with (ii) the optical and electronic performance of PTI. On the basis of our findings, we create an OLED prototype with PTI as the active, metal-free material, and we lay the foundations for device integration of solution-processable graphitic carbon nitride dispersions in semiconductor devices.

Crystalline semiconducting carbon nitrides are chemically and physically resilient, consist of earth abundant elements, and can be exfoliated into 2D atomically thin layers. In particular, poly(triazine imide) (PTI) is a highly crystalline semiconductor, and though no techniques exist to date that enable synthesis of macroscopic monolayers of PTI, it is possible to study it in thin layer device applications that are compatible with its polycrystalline, nanoscale morphology. In our study, we find that the by-product of conventional PTI synthesis is a C-C carbon rich phase that is detrimental for charge transport and photoluminescence. An optimised synthetic protocol yields a PTI material with an increased quantum yield, enabled photocurrent and electroluminescence. In addition, we report that protonation of the PTI structure happens preferentially at the pyridinic nitrogen atoms of the triazine (C3N3) rings, is accompanied by exfoliation of PTI layers, and contributes to increases in quantum yield and exciton lifetimes. This study describes structure-property relationships in PTI that link (i) the nature of defects, their formation, and how to avoid them with (ii) the optical and electronic performance of PTI. On the basis of our findings, we create an OLED prototype with PTI as the active, metal-free material, and we lay the foundations for device integration of solution-processable graphitic carbon nitride dispersions in semiconductor devices.

A multi-level cell (MLC) operation as a 1–3 bit/cell of the FeFET emerging memory is reported by utilizing optimized Si doped hafnium oxide (HSO) and hafnium zirconium oxide (HZO) based on ferroelectric laminates. An alumina interlayer was used to achieve the thickness independent of the HSO and HZO-based stack with optimal ferroelectric properties. Various split thicknesses of the HSO and HZO were explored with lamination to increase the FeFET maximum memory window (MW) for a practical MLC operation. A higher MW occurred as the ferroelectric stack thickness increased with lamination. The maximum MW (3.5 V) was obtained for the HZO-based laminate, the FeFETs demonstrated a switching speed (300 ns), 10 years MLC retention, and 104 MLC endurance. The transition from instant switching to increased MLC levels was realized by ferroelectric lamination. This indicated an increased film granularity and a reduced variability through the interruption of ferroelectric columnar grains. The 2–3 bit/cell MLC levels and maximum MW were studied in terms of the size-dependent variability to indicate the impact of the ferroelectric area scaling. The impact of an alumina interlayer on the ferroelectric phase is outlined for HSO in comparison to the HZO material. For the same ferroelectric stack thickness with lamination, a lower maximum MW, and a pronounced wakeup effect was observed in HSO laminate compared to the HZO laminate. Both wakeup effect and charge trapping were studied in the context of an MLC operation. The merits of ferroelectric stack lamination are considered for an optimal FeFET-based synaptic device operation. The impact of the pulsing scheme was studied to modulate the FeFET current to mimic the synaptic weight update in long-term synaptic potentiation/depression.

The study of hydrogen bonding interactions at the level of functionalized nanoparticles remains highly challenging and poorly explored area. In this work, superparamagnetic iron oxide nanoparticles (SPIONs) were orthogonally functionalized using receptors bearing multiple hydrogen bonding motifs. Pristine SPIONs were modified by wet chemical processes with Hamilton receptors (hosts), or cyanurate‐guest molecules linked to phosphonic acid moieties for monolayer functionalization. The modified surfaces were fully characterized and the number of attached ligands on the surface were determined. The host‐guest interactions on the interface of modified SPIONs were investigated by using UV‐Vis spectroscopic titrations. Functionalized SPIONs demonstrated two to three magnitudes stronger binding affinities as compared to the related molecular interactions in solution due to synergistic effects on complex surface environment. Higher supramolecular binding ratios of host‐guest interactions on the modified surface were emerged. These studies provide fundamental insights into supramolecular complexations on the surface at solid‐liquid interface systems with applications in engineered nanomaterials, nano‐sensing devices, and drug delivery systems.

Background and Objectives Since there is no clear evidence in the literature to show how non-modified single-stranded DNA (ssDNA) drugs are metabolized in humans, we assessed the metabolism of BC 007, an ssDNA therapeutic, under development as a neutralizer of autoantibodies against G-protein-coupled receptors. In-vitro, investigating its stability in monkey plasma and serum, a successive 3′-exonuclease degradation resulting in several n–x degradation products has been previously reported. Here, we investigated the metabolism of BC 007 in humans after intravenous application to autoantibody-positive healthy subjects, in line with Phase I safety testing. Methods 1H-NMR was applied for n–x degradation product search and beta-aminoisobutyric acid (bAIBA) measurement in urine; ultra-performance liquid chromatography–mass spectrometry was also used for the latter. Colorimetric assays were used for quantification of uric acid in serum and urine. Results Fast degradation prohibited the detection of the intermediate n–x degradation products in urine using 1H-NMR. Instead, NMR revealed a further downstream degradation product, bAIBA, which was also detected in serum shortly after initial application. The purine degradation product, uric acid, confirmed this finding of fast metabolism. Conclusion Fast and full degradation of BC 007, shown by nucleic bases degradation products, is one of the first reports about the fate of a ssDNA product in humans.

Silicon-based anodes with lithium ions as charge carriers have the highest predicted charge density of 3579 mA h g-1 (for Li15Si4) while being comparatively safe. Contemporary electrodes do not achieve these theoretical values largely because production paradigms remained unchanged since their inception and rely on the mixing of weakly coordinated, multiple components. In this paper, we present the one-pot synthesis of high-performance anodes that reach the theoretical capacity of the fully lithiated state of silicon. Here, a semi-conductive triazine-based graphdiyne polymer network is grown around silicon nanoparticles directly on the current collector, a copper sheet. The current collector (Cu) acts as the catalyst for the formation of a semi-conductive triazine-based graphdiyne polymer network that grows around the inorganic, active material (Si). In comparison to established electrode assemblies, this process (i) omits any steps related to curing, drying, and annealing, (ii) does away with binders and conductivity-enhancing additives that decrease volumetric and gravimetric capacity, and (iii) cancels out the detrimental effects on performance, chemical and physical stability of conventional, three-component anodes (Si, binder, carbon black). This is because, the porous, semi-conducting organic framework (i) adheres to the current collector on which it grows via cooperative van der Waals interactions, (ii) acts effectively as conductor for electrical charges and binder of silicon nanoparticles via conjugated, covalent bonds, and (iii) enables selective transport of mass and charge-carriers (electrolyte and Li-ions) through pores of defined size. As a result, the anode shows extraordinarily high capacity at the theoretical limit of fully lithiated silicon, excellent performances in terms of cycling (exceeding 70% capacity retention after 100 cycles), and high mechanical and thermal stability. These high-performance anodes pave the way for use in flexible, wearable electronics and in environmentally demanding applications.

COVID-19 is a pandemic respiratory disease that is caused by the highly infectious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Anti-SARS-CoV-2 antibodies are essential weapons that a patient with COVID-19 has to combat the disease. When now repurposing a drug, namely an aptamer that interacts with SARS-CoV-2 proteins for COVID-19 treatment (BC 007), which is, however, a neutralizer of pathogenic autoantibodies in its original indication, the possibility of also binding and neutralizing anti-SARS-CoV-2 antibodies must be considered. Here, the highly specific virus-neutralizing antibodies have to be distinguished from the ones that also show cross-reactivity to tissues. The last-mentioned could be the origin of the widely reported SARS-CoV-2-induced autoimmunity, which should also become a target of therapy. We, therefore, used enzyme-linked immunosorbent assay (ELISA) technology to assess the binding of well-characterized publicly accessible anti-SARS-CoV-2 antibodies (CV07-209 and CV07-270) with BC 007. Nuclear magnetic resonance spectroscopy, isothermal calorimetric titration, and circular dichroism spectroscopy were additionally used to test the binding of BC 007 to DNA-binding sequence segments of these antibodies. BC 007 did not bind to the highly specific neutralizing anti-SARS-CoV-2 antibody but did bind to the less specific one. This, however, was a lot less compared to an autoantibody of its original indication (14.2%, range 11.0–21.5%). It was also interesting to see that the less-specific anti-SARS-CoV-2 antibody also showed a high background signal in the ELISA (binding on NeutrAvidin-coated or activated but noncoated plastic plate). These initial experiments suggest that the risk of binding and neutralizing highly specific anti-SARS CoV-2 antibodies by BC 007 should be low. Transfer-Bonuns

We report on antiferroelectric (AFE) hybrid charge trap (CT) memory with amplified tunnel oxide field via dynamic AFE hysteresis dipole switching. Memory window (4.5V), switching speed (

Improved characteristics of ferroelectric Si:HfO 2 (HSO) MFIS FeFETs by tuning the substrate implant doping concentration is reported. Shallow implant doping gives the possibility to control the FeFET readout range, whereas the deep implant affects the I off current, resulting in a higher I on -I off current ratio. Additionally, the implant tuning improves the switching MFIS field distribution enabling lower FeFET switching voltages. A transition from a charge trap dominated endurance to an endurance that is limited by the interface trap generation is observed when the substrate implant is tuned. An endurance of 105 cycles with approximately 4 orders of magnitude I on -I off residual current ratio is measured on the FeFET devices. The impact of tuning shallow and deep substrate implant profiles is studied with respect to changes of the MFIS stack characteristics and overall FeFET performance.

Increasing demands for new computer architectures may require embedded non-volatile memories as for example in-memory computing. Ferroelectric field-effect transistors (FeFETs) add further advantages besides their outstanding properties due to the availability of both n-type and p-type transistors. The latter favor a different channel materials, like SiGe, due to the low hole mobility in silicon. In this article, we demonstrate the integration of ferroelectric hafnium oxide on SiGe as well as working p-type FeFETs, possessing a large memory window of about 1.1 V and low variability. Such architectures were co-integrated into a standard high-k metal gate (HKMG) CMOS platform. Furthermore, we report on the impact of annealing temperature on the interface and ferroelectric layer, which appears to be universal for SiGe and Si substrates. Here, a growth of the interface layer during annealing at higher temperatures was observed as well as a reduction of the wake-up effect for the ferroelectric layer.

First functional acting autoantibodies against G protein-coupled receptors such as the beta2-adrenoceptor in e.g. asthmatic patients have already been discovered in the early 1980s of the last century using assays that show their functional activity. Today, almost 40 years later, the measurement of such autoantibodies is still a challenge. Bioassays able to show the functional activity of such autoantibodies against G protein-coupled receptors are still the ne plus ultra for their detection and also classification when additionally exploiting specific receptor blockers for the neutralisation of the effect. Bioassays based on living cells make specific demands on the laboratories and are, therefore not suitable for every routine laboratory. Routine diagnostics, therefore, ideally requires different assays based on e.g. solid-phase technology, such as enzyme-linked immunosorbent assay (ELISA) technology. Here, endeavours are going on, using either the exact epitopes of such autoantibodies, if known, for trapping the autoantibodies, or the complete receptor in biological or artificial membranes that are immobilised onto a plastic carrier (ELISA principle). Here, we question and discuss the outcome of such tests, especially, if no controls such as the non-coated plastic carrier or the corresponding receptor-free membrane coat is offered as control in parallel, in light of the manifold experiences already collected with even non-agonistic acting autoantibodies by Güven et al. (J Immunol Methods 403:26-36, 2014).

This study was performed to assess the relation between occupational exposure to N,N-dimethylformamide after an 8 h work shift in the acrylic fibre industry and its three biological markers N-methylformamide (NMFtotal), N-acetyl-S-(N-methylcarbamoyl)cysteine (AMCC), and N-methylcarbamoyl adduct at haemoglobin (MCVal). External DMF exposure of 220 workers was determined during the whole shift. A standardised questionnaire was used to obtain information about the worker’s general health status, medical treatment, smoking habits, protective measures, and possible symptoms caused by DMF exposure. NMF and AMCC were analysed in post-shift urine samples and MCVal in blood. For longitudinal assessment the average AMCC concentration was determined over a period of 4 weeks (weekly sampling) in a sub-collective of 89 workers. The median of DMF concentration in air was 3.19 mg/m3 (range

Combination treatment of molecular targeted and external radiotherapy is a promising strategy and was shown to improve local tumor control in a HNSCC xenograft model. To enhance the therapeutic value of this approach, this study investigated the underlying molecular response. Subcutaneous HNSCC FaDuDD xenografts were treated with single or combination therapy (X-ray: 0, 2, 4 Gy; anti-EGFR antibody (Cetuximab) (un-)labeled with Yttrium-90 (90Y)). Tumors were excised 24 h post respective treatment. Residual DNA double strand breaks (DSB), mRNA expression of DNA damage response related genes, immunoblotting, tumor histology, and immunohistological staining were analyzed. An increase in number and complexity of residual DNA DSB was observed in FaDuDD tumors exposed to the combination treatment of external irradiation and90Y-Cetuximab relative to controls. The increase was observed in a low oxygenated area, suggesting the expansion of DNA DSB damages. Upregulation of genes encoding p21cip1/waf1 (CDKN1A) and GADD45? (GADD45A) was determined in the combination treatment group, and immunoblotting as well as immunohistochemistry confirmed the upregulation of p21cip1/waf1. The increase in residual H2AX foci leads to the blockage of cell cycle transition and subsequently to cell death, which could be observed in the upregulation of p21cip1/waf1 expression and an elevated number of cleaved caspase-3 positive cells. Overall, a complex interplay between DNA damage repair and programmed cell death accounts for the potential benefit of the combination therapy using90Y-Cetuximab and external radiotherapy., TU Dresden Faculty of Medicine Carl Gustav Carus; MedDrive; European Union (EU); 6th Framework; EU-Project ‘‘BioCare”; German Federal Ministry of Education and Research; German Research Foundation

In the present study we investigated the internal exposure situation of infant patients to the plasticizers TEHTM (tri-2-ethylhexyl trimellitate) and DEHP (di-2-ethylhexyl phthalate). The study collective included 21 infant patients aged 2–22 months that had to undergo cardiac surgery using cardio pulmonary bypass (CPB). Each patient, but one, received blood products during surgery. A special feature was that the used CPB tubings were exclusively plasticized with the alternative plasticizer TEHTM and were free of the standard plasticizer DEHP, that raises increasing toxicological concern. The blood products were stored in DEHP plasticized blood bags. Blood and urine samples of each infant patient were analysed before and after the surgery for the levels of the plasticizers DEHP and TEHTM and their metabolites. In general, the plasticizers were detected in the post-surgery blood samples only, with TEHTM in low levels (median 18.4 μg/L) and DEHP in rather elevated levels (median 1046 μg/L). With respect to the urine samples, TEHTM metabolites were not detected in any of the samples. DEHP metabolites were found in all urine samples, however, in significantly increased median levels in the post-surgery urine samples of the infants (increase factor 5–26). Thus, the present study clearly demonstrates the strong contribution of standard medical procedures to the internal plasticizer burden of patients. Particularly with regard to the suspected endocrine disrupting activities of the phthalate plasticizer DEHP, the elevated internal levels of this plasticizer and its metabolites in infants following cardiac surgery are alarming.

Infrared (IR) spectroscopy of liquid biopsies shows high potential to become a non-invasive, cost-efficient and fast diagnostic tool for several types of cancers, acute myocardial infarction, Alzheimer's disease as well as possibly other pathologies [1]. However, interpretation of the disease-induced changes in an IR absorption spectrum remains challenging due to high molecular complexity of the samples. Here we perform for the first time Fourier-Transform IR (FTIR) absorption and non-targeted mass spectrometry (MS) based proteomic measurements of the very same set of human blood plasma samples, collected from lung cancer patients and a control group. This combination shows that the IR spectroscopic fingerprint of lung cancer is caused by differential regulation of a number of plasma proteins. Generally, quantitative analysis of cancer-induced changes in blood composition is of paramount importance for cancer diagnostics, and for improving IR spectroscopic fingerprinting approaches in particular.

We present a new custom-built cell for high-resolution absorption spectroscopy of hazardous gases. The use of an aluminum light-pipe enables sensitive detection due to the small tube diameter and an increased particle density in the interaction volume for a limited analyte amount in the cell, while avoiding additional surfaces such as mirrors. To demonstrate this, we have used the cell to measure tritiated water isotopologues (HTO and traces of T2O) for which spectroscopic data is scarce, due to the challenge of performing spectroscopy of these highly radio-chemical aggressive substances. For this purpose, the new cell also features the efficient inline-production of tritiated water. In this paper we present the concept of the light-pipe cell and demonstrate its performance with a high-resolution absorption spectrum of gaseous HTO generated inside of this cell.

Bioremediation via floating treatment wetlands/islands (FTW/I) is a sustainable, upcoming strategy to clean over-fertilized waters. Heavy metal pollution could be addressed in the same system. For implementing this feature, heavy-metal-adsorbing filter papers were prepared in a scalable procedure. Polyamine-functionalized papers based on the grafting of polyethyleneimine (PEI) and chitosan were prepared in aqueous immersion baths and tested for their heavy metal adsorption capability. Compared to untreated cellulose, the prepared filter papers exhibited great heavy metal reduction in a filtration setup. Compellingly, the natural biopolymer functionalization with chitosan adsorbed similar or even higher amounts (80% Ni, 65% Co, 100% Cu, 85% Fe, 40% Cr, 90% Cd, and 66% Zn of the 5 ppm heavy metal sulfate solutions) compared to the PEI filters (48% Ni, 36% Co, 89% Cu, 96% Fe, 45% Cr, 84% Cd, and 62% Zn) at pH 6.5. Moreover, the filters can be re-used simply by acidic washing to desorb the heavy metals, which was demonstrated in five repeating cycles. The presented chitosan–cellulose papers were prepared from renewable resources in a 3-step production lane and are a sustainable choice for various heavy-metal-removing applications. The papers can be implemented into floating treatment wetland systems to protect plants and microorganisms during phytoremediation processes and to add the additional feature of heavy metal removal for FTWs.

We present a simple but accurate algorithm to calculate the flow and shear rate profile of shear thinning fluids, as typically used in biofabrication applications, with an arbitrary viscosity-shear rate relationship in a cylindrical nozzle. By interpolating the viscosity with a set of power-law functions, we obtain a mathematically exact piecewise solution to the incompressible Navier-Stokes equation. The algorithm is validated with known solutions for a simplified Carreau-Yasuda fluid, full numerical simulations for a realistic chitosan hydrogel as well as experimental velocity profiles of alginate and chitosan solutions in a microfluidic channel. We implement the algorithm in an easy-to-use Python tool, included as Supplementary Material, to calculate the velocity and shear rate profile during the printing process, depending on the shear thinning behavior of the bioink and printing parameters such as pressure and nozzle size. We confirm that the shear stress varies in an exactly linear fashion, starting from zero at the nozzle center to the maximum shear stress at the wall, independent of the shear thinning properties of the bioink. Finally, we demonstrate how our method can be inverted to obtain rheological bioink parameters in-situ directly before or even during printing from experimentally measured flow rate versus pressure data.

The plasticizer di(2-ethylhexyl)phthalate (DEHP) is often used for PVC medical devices, that are also largely used for intensive care medical treatments, like extracorporeal membrane oxygenation (ECMO) therapy. Due to the toxicological potential of DEHP, the inner exposure of patients with this plasticizer is a strong matter of concern as many studies have shown a high leaching potential of DEHP into blood. In this study, the inner DEHP exposure of patients undergoing ECMO treatment was investigated. The determined DEHP blood levels of ECMO patients and the patients of the control group ranged from 31.5 to 1009 μg/L (median 156.0 μg/L) and from 19.4 to 75.3 μg/L (median 36.4 μg/L), respectively. MEHP blood levels were determined to range from < LOD to 475 μg/L (median 15.9 μg/L) in ECMO patients and from < LOD to 9.9 μg/L (median 3.7 μg/L) in the control group patients, respectively. Increased DEHP exposure was associated with the number of cannulas and membranes of the ECMO setting, whereas residual diuresis decreased the exposure. Due to the suspected toxicological potential of DEHP, its use in medical devices should be further investigated, in particular for ICU patients with long-term exposure to PVC, like in ECMO therapy.

Agonistically acting autoantibodies directed against the adrenergic beta-1 receptor (beta1-AABs) are a pathogenic factor in diseases of the heart and circulatory system such as dilated cardiomyopathy. Here we describe the detection of such functionally active beta1-AABs from serum samples using spontaneously beating neonatal rat cardiomyocytes, which express the fully functional adrenergic beta-1 receptor coupled with the signal transduction pathway that induces chronotropy. With serum samples added (containing beta1-AABs), an increased positive chronotropic effect is caused that can be blocked by the subsequent addition of specific beta-blockers (abolishing this chronotropic response). The return to the basal beat rate of the cells by the addition of a beta-blocker proves the adrenergic beta-1 receptor specificity of the serum sample.

Possible unwanted folding of biopharmaceuticals during manufacturing and storage has resulted in analysis schemes compared to small molecules that include bioanalytical characterization besides chemical characterization. Whether bioanalytical characterization is required for nucleotide-based drugs, may be decided on a case-by-case basis. Nucleotide-based pharmaceuticals, if chemically synthesized, occupy an intermediate position between small-molecule drugs and biologics. Here, we tested whether a physicochemical characterization of a nucleotide-based drug substance, BC 007, was adequate, using circular dichroism (CD) spectroscopy. Nuclear magnetic resonance confirmed CD data in one experimental setup. BC 007 forms a quadruplex structure under specific external conditions, which was characterized for its stability and structural appearance also after denaturation using CD and nuclear magnetic resonance. The amount of the free energy (ΔG 0 ) involved in quadruplex formation of BC 007 was estimated at +8.7 kJ/mol when dissolved in water and +1.4 kJ/mol in 154 mM NaCl, indicating structural instability under these conditions. However, dissolution of the substance in 5 mM of KCl reduced the ΔG 0 to −5.6 kJ/mol due to the stabilizing effect of cations. These results show that positive ΔG 0 of quadruplex structure formation in water and aqueous NaCl prevents BC 007 from preforming stable 3-dimensional structures, which could potentially affect drug function.

A wealth of studies have confirmed that the low-field hysteresis behaviour of ferroelectric bulk ceramics and thin films can be described using Rayleigh relations, and irreversible domain wall motion across the array of pining defects has been commonly accepted as the underlying micro-mechanism. Recently, HfO2 thin films incorporated with various dopants were reported to show pronounced ferroelectricity, however, their microscopic domain structure remains unclear till now. In this work, the effects of the applied electric field amplitude, frequency and temperature on the sub-coercive polarization reversal properties were investigated for 10 nm thick Si-doped HfO2 thin films. The applicability of the Rayleigh law to ultra-thin ferroelectric films was first confirmed, indicating the existence of a multi-domain structure. Since the grain size is about 20–30 nm, a direct observation of domain walls within the grains is rather challenging and this indirect method is a feasible approach to resolve the domain structure. (© 2015 WILEY-VCH Verlag GmbH &Co. KGaA, Weinheim)

The working group “Analyses in Biological Materials” of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area verified the present biomonitoring method. The described method allows the simultaneous determination of the metabolites of hexamethylene diisocyanate (HDI), 2,4-toluenediamine and 2,6-toluene diisocyanate (TDI), isophorone diisocyanate (IPDI) and methylene diphenyl diisocyanate (MDI) in human urine. After acid hydrolysis the released amines, hexamethylenediamine (HDA), 2,4-, and 2,6-toluenediamine (TDA), isophorone diamine (IPDA) and 4,4′-methylenedianiline (4,4′-MDA) are extracted from urine, derivatised using heptafluorobutyric anhydride and quantified by NCI-GC-MS. The method was extensively validated and the reliability data were confirmed by independent laboratories, which have established and cross-checked the whole procedure Keywords: Hexamethylendiisocyanat; HDI; 2,4-Toluylendiisocyanat; 2,4-TDI; 2,6-Toluylendiisocyanat; 2,6-TDI; Isophorondiisocyanat; IPDI; Diphenylmethan-4,4′-diisocyanat; MDI; Hexamethylendiamin; HDA; 2,4-Toluylendiamin; 2,4-TDA; 2,6-Toluylendiamin; 2,6-TDA; Isophorondiamin; IPDA; 4,4′-Diaminodiphenylmethan; MDA; Urin; Biomonitoring; Analysen in biologischem Material; Gaschromatographie

The working group “Analyses in Biological Materials” of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area verified the present biomonitoring method. The described method allows the simultaneous determination of the metabolites of hexamethylene diisocyanate (HDI), 2,4-toluene diisocyanate and 2,6-toluene diisocyanate (TDI), isophorone diisocyanate (IPDI) and methylene diphenyl diisocyanate (MDI) in human urine. After acid hydrolysis the released amines, hexamethylenediamine (HDA), 2,4-toluenediamine, and 2,6-toluenediamine (TDA), isophorone diamine (IPDA) and 4,4′-methylenedianiline (4,4′-MDA) are extracted from urine, derivatised using heptafluorobutyric anhydride and quantified by NCI-GC-MS. The method was extensively validated and the reliability data were confirmed by independent laboratories, which have established and cross-checked the whole procedure. Keywords: hexamethylene diisocyanate; HDI; 2,4-toluene diisocyanate; 2,4-TDI; 2,6-toluene diisocyanate; 2,6-TDI; isophorone diisocyanate; IPDI; methylene diphenyl diisocyanate; MDI; hexamethylenediamine; HDA; 2,4-toluenediamine; 2,4-TDA; 2,6-toluenediamine; 2,6-TDA; isophorone diamine; IPDA; 4,4′-methylene dianiline; MDA; urine; biomonitoring; analyses in biological materials; gas chromatography

A new and fast HPLC-method for the simultaneous determination of tri-(2-ethylhexyl) trimellitate (TOTM or TEHTM), its diesters 2,4-di-(2-ethylhexyl) trimellitate (2,4-DEHTM), 1,4-di-(2-ethylhexyl) trimellitate (1,4-DEHTM), 1,2-di-(2-ethylhexyl) trimellitate (1,2-DEHTM) and monoesters 1-mono-(2-ethylhexyl) trimellitate (1-MEHTM), 2-mono-(2-ethylhexyl) trimellitate (2-MEHTM) and 4-mono-(2-ethylhexyl) trimellitate (4-MEHTM) together with di-(2-ethylhexyl) phthalate (DEHP) and its primary metabolite mono-(2-ethylhexyl) phthalate (MEHP) in blood was developed and validated. The analytes are extracted from blood using liquid–liquid extraction and are chromatographically separated by reversed-phase HPLC using core shell material. Quantitative assessment was performed by ESI-tandem mass spectrometry in negative ionization mode using stable isotope dilution. In less than 30 min six postulated primary metabolites of TOTM along with the DEHP metabolite MEHP can be selectively and sensitively quantified. Additionally, the method enables the determination of the parent plasticizers TOTM and DEHP. The detection limits in blood were found to range between 0.7–5.5 μg/L for all TOTM analytes. Precision and repeatability of the method were proven by relative standard deviations between 0.9% and 8.7%. TOTM, an alternative plasticizer to DEHP, is already increasingly used for medical devices. Nevertheless, data about the human metabolism of TOTM are still limited. The presented method is the first one enabling the simultaneous determination of the parent plasticizers TOTM and DEHP together with their primary degradation products (DEHTM, MEHTM, MEHP) and can thus be applied manifold including the investigation of the human metabolism of TOTM.

Static domain structures and polarization dynamics of silicon doped HfO2 are explored. The evolution of ferroelectricity as a function of Si-doping level driving the transition from paraelectricity via ferroelectricity to antiferroelectricity is investigated. Ferroelectric and antiferroelectric properties can be observed locally on the pristine, poled and electroded surfaces, providing conclusive evidence to intrinsic ferroic behavior.

The ferroelectric behaviour of silicon doped hafnium oxide has been investigated using metal–insulator–metal capacitor structures for film thicknesses of 9 and 27 nm, annealing temperatures between 450 and 1000 °C and silicon contents from 0 to 8.5 cat%. For the 9 nm thick films, an improvement of the ferroelectric remanent polarization was revealed for decreasing silicon content and increasing annealing temperature, which corresponds well with the HfO 2 structural phases observed by x-ray diffraction. An increase of the film thickness up to 27 nm induced an apparent decrease of the remanent polarization and modified the temperature dependence. This change in the ferroelectric properties was shown to be determined by the different crystallization behaviour of the thick films with respect to the thin films.

Analysis of organic residues in pottery vessels has been successful in detecting a range of animal and plant products as indicators of food preparation and consumption in the past. However, the identification of plant remains, especially grain crops in pottery, has proved elusive. Extending the spectrum is highly desirable, not only to strengthen our understanding of the dispersal of crops from centres of domestication but also to determine modes of food processing, artefact function and the culinary significance of the crop. Here, we propose a new approach to identify millet in pottery vessels, a crop that spread throughout much of Eurasia during prehistory following its domestication, most likely in northern China. We report the successful identification of miliacin (olean-18-en-3β-ol methyl ether), a pentacyclic triterpene methyl ether that is enriched in grains of common/broomcorn millet (Panicum miliaceum), in Bronze Age pottery vessels from the Korean Peninsula and northern Europe. The presence of millet is supported by enriched carbon stable isotope values of bulk charred organic matter sampled from pottery vessel surfaces and extracted n-alkanoic acids, consistent with a C4 plant origin. These data represent the first identification of millet in archaeological ceramic vessels, providing a means to track the introduction, spread and consumption of this important crop.

Addendum to: Di(2-ethylhexyl) phthalate (DEHP) metabolites in urine Mono-n-butyl phthalate (MnBP) and monoiso-butyl phthalate (MiBP) in urine The documentation presents the determination of mono-n-butyl phthalate (MnBP) and mono-iso-butyl phthalate (MiBP) in urine, which are metabolites of the prominent plasticizers di-n-butyl phthalate (DnBP) and diisobutyl phthalate (DiBP). The urine samples are buffered to pH = 6.5 and subjected to enzymatic hydrolysis, together with the deuterium-labelled internal standard. An arylsulfatase-free β-glucuronidase is used for hydrolysis. After separation of possible precipitates by centrifugation, the hydrolysate is injected into the LC–MS/MS system. The analytes are concentrated and higher molecular matrix compounds and more polar substances are separated using a RAM phase column. By employing a backflush, the analytes are rinsed off onto an analytical phenyl-hexyl column where they are chromatographically separated. Tandem mass spectrometry allows for highly selective detection of the analytes. For calibration, aqueous standard solutions with known concentrations of MnBP and MiBP are used and processed in the same way as the urine samples. For quality control, pooled urines containing high and low native MnBP and MiBP levels were used. The procedure for the determination of DnBP and DiBP metabolites corresponds to the HPLC–MS/MS method for the determination of the main metabolites of Di(2-ethylhexyl) phthalate (DEHP) in the urine of occupationally or environmentally exposed persons. The present method is therefore an addendum to the procedure for the determination of the DEHP metabolites. Keywords: Di(2-ethylhexyl)phthalat; DEHP; Di-n-butylphthalat; DnBP; Metabolite; Urin; Mono-n-butylphthalat; MnBP; Mono-iso-butylphthalat; MiBP; Di-n-butylphthalat; Di-iso-butylphthalat; DiBP; Biomonitoring; Biologisches Monitoring; LC-MS/MS

Monotremes are the most basal egg-laying mammals comprised of two extant genera, which are largely nocturnal. Visual pigments, the first step in the sensory transduction cascade in photoreceptors of the eye, have been examined in a variety of vertebrates, but little work has been done to study the rhodopsin of monotremes. We isolated the rhodopsin gene of the nocturnal short-beaked echidna (Tachyglossus aculeatus) and expressed and functionally characterized the proteinin vitro. Three mutants were also expressed and characterized: N83D, an important site for spectral tuning and metarhodopsin kinetics, and two sites with amino acids unique to the echidna (T158A and F169A). Theλmaxof echidna rhodopsin (497.9 ± 1.1 nm) did not vary significantly in either T158A (498.0 ± 1.3 nm) or F169A (499.4 ± 0.1 nm) but was redshifted in N83D (503.8 ± 1.5 nm). Unlike other mammalian rhodopsins, echidna rhodopsin did react when exposed to hydroxylamine, although not as fast as cone opsins. The retinal release rate of light-activated echidna rhodopsin, as measured by fluorescence spectroscopy, had a half-life of 9.5 ± 2.6 min−1, which is significantly shorter than that of bovine rhodopsin. The half-life of the N83D mutant was 5.1 ± 0.1 min−1, even shorter than wild type. Our results show that with respect to hydroxylamine sensitivity and retinal release, the wild-type echidna rhodopsin displays major differences to all previously characterized mammalian rhodopsins and appears more similar to other nonmammalian vertebrate rhodopsins such as chicken and anole. However, our N83D mutagenesis results suggest that this site may mediate adaptation in the echidna to dim light environments, possiblyviaincreased stability of light-activated intermediates. This study is the first characterization of a rhodopsin from a most basal mammal and indicates that there might be more functional variation in mammalian rhodopsins than previously assumed.

Haemoglobin adducts are highly valuable biomarkers of cumulative exposure to carcinogenic substances. We have developed and applied an analytical method for the simultaneous quantification of five haemoglobin adducts of important occupational and environmental carcinogens. The N-terminal adducts were determined with gas chromatography as pentafluorophenylthiohydantoine derivatives according to the modified Edman-procedure and subsequent acetonization of the glycidamide adduct N-(R,S)-2-hydroxy-2-carbamoylethylvaline (GAVal). The use of self-synthesized labelled internal standards in combination with tandem mass spectrometry using negative chemical ionisation guarantees both high accuracy and sensitivity of our determination. The limit of detection for N-2-hydroxyethylvaline (HEVal), N-(R,S)-2-hydroxypropylvaline (HPVal), N-2-carbamoylethylvaline (AAVal) and N-(R,S)-2-hydroxy-2-carbamoylethylvaline (GAVal) was 2 pmol/g globin, for N-2-cyanoethylvaline (CEVal) it was determined as 0.5 pmol/g globin, which was sufficient to determine the background levels of these adducts in the non-smoking general population. The between-day-precision for all analytes using a human blood sample as quality control material ranged from 4.7 to 12.3%. We investigated blood samples of a small group (n = 104) of non-smoking persons of the general population for the background levels of these haemoglobin adducts. The median values for HEVal, HPVal, CEVal, AAVal and GAVal in a group of 92 non-smoking persons were 18.1, 4.1

The recent discovery of ferroelectricity in thin film HfO2 materials renewed the interest in ferroelectric FET (FeFET) as an emerging nonvolatile memory providing a potential high speed and low power Flash alternative. Here, we report more insight into FeFET performance by integrating two types of ferroelectric (FE) materials and varying their properties. By varying the material type [HfO2 (HSO) versus hafnium zirconium oxide (HZO)], optimum content (Si doping/mixture ratio), and film thickness, a material relation to FeFET device physics is concluded. As for the material type, an improved FeFET performance is observed for HZO integration with memory window (MW) comparable to theoretical values. For different Si contents, the HSO based FeFET exhibited a MW trend with different stabilized phases. Similarly, the HZO FeFET shows MW dependence on the Hf:Zr mixture ratio. A maximized MW is obtained with cycle ratios of 16:1 (HfO2:Si) and 1:1 (Hf:Zr) as measured on HSO and HZO based FeFETs, respectively. The thickness variation shows a trend of increasing MW with the increased FE layer thickness confirming early theoretical predictions. The FeFET material aspects and stack physics are discussed with insight into the interplay factors, while optimum FE material parameters are outlined in relation to performance.

Cell-based analytics for the detection of the beta1-adrenoceptor autoantibody (beta1-AAB) are functional, yet difficult to handle, and should be replaced by easily applicable, routine lab methods. Endeavors to develop solid-phase-based assays such as ELISA to exploit epitope moieties for trapping autoantibodies are ongoing. These solid-phase-based assays, however, are often unreliable when used with human patient material, in contrast to animal derived autoantibodies. We therefore tested an immunogen peptide-based ELISA for the detection of beta1-AAB, and compared commercially available goat antibodies against the 2nd extracellular loop of human beta1-adrenoceptor (ADRB1-AB) to autoantibodies enriched from patient material. The functionality of these autoantibodies was tested in a cell based assay for comparison and their structural appearance was investigated using 2D gel electrophoresis. The ELISA showed a limit of detection for ADRB1-AB of about 1.5 nmol antibody/L when spiked in human control serum and only about 25 nmol/L when spiked in species identical (goat) matrix material. When applied to samples of human origin, the ELISA failed to identify the specific beta1-AABs. A low concentration of beta1-AAB, together with structural inconsistency of the patient originated samples as seen from the 2D Gel appearance, might contribute to the failure of the peptide based ELISA technology to detect human beta1-AABs.

A crucial challenge for including biophysical photosynthesis–transpiration models into complex crop growth models is to integrate the plasticity of photosynthetic processes that is related to factors like nitrogen (N) content, age, and rank of leaves, or to the adaptation of plants to growth temperature ( T g ). Here we present a new version of the combined photosynthesis-stomatal conductance model LEAFC3-N [Muller, J., Wernecke, P., Diepenbrock, W., 2005. LEAFC3-N: a nitrogen sensitive extension of the CO 2 and H 2 O gas exchange model LEAFC3 parameterised and tested for winter wheat ( Triticum aestivum L.). Ecological Modelling 183, 183–210.] that was revised, extended and completely re-parameterised for barley ( Hordeum vulgare L.) with special regard for these factors to facilitate the use of the model in ecophysiological studies and in crop modelling. The analysis is based on novel comprehensive data on photosynthetic CO 2 and light response curves measured at two oxygen concentrations and different temperatures on leaves of barley ( H. vulgare L.) differing in leaf N and chlorophyll content. Plants were grown in climatic chambers or in the field at different N and T g . We thoroughly revised the existing and introduced new nitrogen relations for key model parameters that account for a linear increase with leaf N of V max , J max, T p , and R dmax (maximum rates of carboxylation, electron transport, triose phosphate export, and mitochondrial respiration), a saturation-type increase of φ (quantum yield of electron transport), and a non-linear decrease of θ and m (curvature of the light dependence of electron transport rate, scaling factor of the stomata model). The adaptation of photosynthetic characteristics to T g was included into the model by linear relations that were observed between T g and the activation energy Δ H a of the temperature response characteristics of V max , J max , and T p as well as of the nitrogen dependency of these characteristics. Based on an analysis of diurnal time courses of gas exchange rates it was found necessary including not only the relation between leaf water potential ( Ψ ) and stomatal conductance as used originally in LEAFC3, but additional effects on V max and J max . With the above-listed extensions, the model was capable to reproduce the observed plasticity and the recorded diurnal time courses of gas exchange rates fairly well. Thus, we conclude that the new model version can be used under a broad range of conditions, both for ecophysiological studies and as a submodel of crop growth models. The results presented here for barley will facilitate adapting photosynthesis models like LEAFC3-N to other C 3 -species as well. The modelling of the effects of drought stress should be further elaborated in future based on more specific experiments.

Polarity asymmetries in J-V and C-V characteristics of symmetrical MIM capacitors with amorphous and crystalline Zr"("1"-"x")Al"xO"2 films and TiN electrodes are evaluated. Physical analysis of the interface between the TiN bottom electrode and the ZrO"2 layer reveals that the TiN bottom electrode undergoes enhanced oxidation during crystallization of ZrO"2. Simultaneously, nitrogen is incorporated into ZrO"2 near the TiN interface, and an intermixing of ZrO"2 and TiO"2 was identified by AR-XPS and SIMS. This asymmetry results in significant band offset differences for top and bottom electrodes of the crystalline MIM capacitor. Conduction mechanisms are correlated to amorphous vs. crystalline film properties. In addition, asymmetrical charge trapping and a higher trap density is found for crystalline Zr"("1"-"x")Al"xO"2 compared to amorphous films, leading to a polarity dependence in the leakage currents.

Summary: Cells of Saccharomyces cerevisiae 21 (S. uvarum) and Candida albicans which were grown in a chemically defined medium with and without additional calcium ions for 12 h and treated with zymolyase turned into protoplasts. But when grown under calcium deficiency for 24 h only C. albicans formed protoplasts, whereas S. cerevisiae 21 failed to do so. In this specific strain other physiological and ultrastructural changes are observed too. The results may lead to the conclusion that calcium deficiency specifically induces marked changes of the cell wall surface in certain yeast strains thereby masking the lytic sites or making them unaccessible for the enzyme. Zusammenfassung: Zellen von Saccharomyces cerevisiae 21 (S. uvarum) und Candida albicans, die 12 h lang in einem chemisch definierten Medium mit und ohne Kalzium-Ionen gewachsen und mit Zymolyase behandelt worden waren, wandelten sich in Protoplasten um. Wurden die Zellen dagegen 24 h unter Kalzium-Mangel gehalten, wandelten sich nur die Candida albicans-Zellen, nicht jedoch S. cerevisiae, in Protoplasten um. In dem letztgenannten Stamm wurden auch andere physiologische und ultra-strukturelle Eigenschaften beobachtet. Die Ergebnisse lassen den Schlus zu, das Kalzium-Mangel in bestimmten Hefestammen zu deutlichen Veranderungen der Zellwandoberflache fuhrt, wodurch die Lyse-Angriffspositionen maskiert oder fur das Enzym unzuganglich gemacht werden.

Summary. Yeast cultures of Histoplasma capsulatum var. duboisii and H. capsulatum var. capsulatum in collagen containing defined, semi-defined and complex media produced extracellular collagenolytic proteinases, assayed using 4-phenylazo-benzyloxycarbonyl-L-propyl-L-leucyl-glycyl-L-propyl-D-arginine, a specific collagenase substrate. Significant levels of hydroxyproline were measured in the cultures and clear zones of hydrolysis were produced in collagen buffer agar by the crude enzyme preparations. Hydrolysis of casein and bovine serum albumin at pH 8 suggests the presence, in the crude enzymes, of multiple proteinases rather than a collagenase with broad substrate specificity since collagenolytic activity was not detected at pH 5 and above. Collagenolytic activities in the crude enzymes of both fungi were optimal at pH 4, 40 °C and were inhibited by EDTA, phosphoramidion and aprotinin indicating a metallo-serine nature. The molecular weights, estimated by column chromatography, were both 17 kD. The enzymes probably constitute a shared antigen. A probable role in the pathogenesis of histoplasmosis is discussed. Zusammenfassung. Histoplasma capsulatum var. duboisii und H. capsulatum var. capsulatum, in der Hefephase in Collagen-haltigen definierten, semidefinierten und komplexen Kulturmedien kultiviert, bildeten extrazellulare collagen-olytische Proteinasen; diese wurden mittels 4-Phenylazo-benzyloxycarbonyl-L-propyl-L-leucyl-glycyl-L-propyl-D-arginin, einem spezifischen Collagenase-Substrat, nachgewiesen. In den Kulturen wurden signifikante Mengen von Hydroxy-prolin gemessen, und in gepuffertem Collagen-Agar verursachten Rohenzympraparationen klare Hydrolyse-Zonen. Die Hydrolyse von Casein und Rinderserumalbumin bei pH 8 last in den Rohenzympraparationen die Anwesenheit noch weiterer Proteinasen vermuten; die Existenz einer einzigen Collagenase mit breiter Substratspezifi-tat erscheint dagegen eher unwahrscheinlich, da bei pH 5 und daruber collagenolytische Aktivitat nicht nachgewiesen werden konnte. Die collagenolytische Aktivitat in den Rohenzympraparaten beider Pilzarten war bei 40 °C und pH 4 optimal ausgepragt und konnte durch EDTA, Phosphoramidion und Aprotinin gehemmt werden, was fur eine Metalloserin-Natur des Enzyms spricht. Das saulenchromatographisch bestimmte Molekulargewicht betrug beide Male 17 kD. Die Enzyme stellen wahrscheinlich ein beiden Arten gemeinsames Antigen dar. Ihre mogliche Rolle in der Pathogenese der Histoplasmose wird diskutiert.

Zusammenfassung: Asteroid Bodies an Candida-Zellen sind haufig in Vaginalmaterial von Kolpitis-Patientinnen zu beobachten. Die Asteroid Bodies stellen die morphologisch extreme Auspragung des umfassenderen Phanomens der Bildung von Antigen-Antikorper-Prazipitaten auf der Ausenseite der Pilzzellwand in der chronischen Infektsituation dar. Derartige Zellwandauflagen sind pathognomonisch. Das Antigenmaterial ist im Uberschus vorhanden. Antigen-Antikorper-Komplexe werden in das Infektionsmilieu in betrachtlichen Quantitaten freigesetzt. Bei der selten beobachteten Phagocytose der Pilzzellen geht die massive Antigen-Antikorper-Schicht der Zellwandoberflache verloren. Summary: Candida asteroid bodies can often be observed in vaginal scrapings of colpitis patients. Asteroid bodies are the morphologically extreme expression of the more common phenomenon of building up of antigen-antibody precipitates on the external surface of fungal cells in chronic infections. Such external cell wall layers are pathognomonic. Antigenic material is present in excess. Antigen-antibody complexes are liberated into the site of infection in remarkable quantities. The external cell wall layer is liberated from the Candida cells during phagocytosis – a process which can only rarely be observed.

Ten saturated and three unsaturated fatty acids over a wide spectrum of their carbon chain length were tested for their fungitoxicity against five dermatophytes. The experiments showed that short chain saturated fatty acids (C 7:0-C 11:0) are more toxic to dermatophytes than long chain ones (> C 12:0). The antifungal activity decreases with increasing carbon chain length in the even-numbered carbon chain series. Odd-numbered carbon fatty acids show irregularities in these respects. Undecanoic acid (C 11:0) is outstandingly most toxic in the C 7:0-C 18:0 series. Polyunsaturated fatty acids are more toxic than their corresponding saturated acids. The per cent growth inhibition decreased from day 4 to day 12 at all concentrations suggesting the degradation and/or utilization of fatty acids by the fungi during the observation period. The results are discussed on the background of the biochemistry of fatty acids.

Summary. Extracellular elastolytic proteinase was produced by yeast cultures of Histoplasma capsulatum var. duboisii and H. capsulatum var. capsulatum in three different induction media, assayed using elastin-orcein as the substrate. Medium-dependent variations in the time-course for enzyme production were observed and no peak was recorded. The proteinases hydrolysed both casein and bovine serum albumin indicating a broad substrate specificity. Both elastolytic proteinases had similar optimum pH (pH 8) and temperature (35 °C); over 90% residual elastolytic activity was measured in the crude enzymes of v. duboisii and v. capsulatum after incubation in the pH ranges 4.5–8.0 and 4.0–7.0 respectively, at 4 °C for 24 h. The proteinases were not significantly inhibited by any of the tested proteinase inhibitors. The molecular weights, estimated by column chromatography, were 23 kD. A probable role in the pathogenesis of histoplasmosis is discussed. Zusammenfassung. Extrazellulare, elastoly-tische Proteinasen wurden von Histoplasma capsulatum var. duboisii und H. capsulatum var. capsulatum gebildet, die in drei unterschiedlichen Induktionsmedien kultiviert wurden; die Enzyme wurden mittels Elastin-Orcein als Substrat nachgewiesen. Es wurden medienabhangige Variationen im Zeitablauf der Enzymproduktion beobachtet, jedoch wurde kein Sattigungsniveau erreicht. Beide Proteinase-Praparationen hydrolysierten Casein und Rinderserumalbumin und zeigten somit breite Substratspezifitat. Beide elastoly-tische Proteinasen hatten mit pH 8 ein ahnliches pH-Optimum und mit 35 °C gleiche Optimaltemperaturen. Nach Inkubation in den pH-Bereichen 4.5–8.0, bzw. 4.0–7.0 uber 24 h lang bei 4 °C wurde in den Rohenzympraparaten noch uber 90% elastolytische Restaktivitat gemessen. Die Proteinasen wurden von keinen der getesteten Proteinase-Inhibitoren signifikant gehemmt. Das saulenchromatographisch bestimmte Molekulargewicht betrug fur beide Arten 23 kD. Eine mogliche Rolle in der Pathogenese der Histoplasmose wird diskutiert.

Zusammenfassung Der Ort von Antigen-Antikorper-Reaktionen wird mit der indirekten Immunoferritin-Methode elektronenmikroskopish dargestellt. Die Spezifitat der Reaktion wird belegt. Das Verteilungsmuster der Antikorper auf der Candida-Zelloberflache wird uncer Bezug auf die Struktur der ausersten Oberflachenshicht diskutiert. Die raumlichen Beziehungen agglutinierter Candida-Zellen werden untersuht. Die Methode kann uber die Verwendung monospezifischer, ferritin-markiertet Anti- Candida-Seren im direkten Immunoferritin-Test zur Untersuchung der Antigen-Topo- graphie der Pilzzellwand verwendet werden. Der indirekte Immunoferritin-Test — wie er hier vorgestellt wird — ermoglicht Untersumungen uber die Bedeutung der gegen Candidu-Antigene gerichteten Antikorper im Zuge der Wirt-Parasit-Auseinandersetzung bei Infektionsprozessen. Summary The sites of antigen-antibody reactions are made evident by the indirect immunoferritin method. The specifity of the reaction is proved. The distribution pattern of the antibodies on the Candida cell surface is discussed with relation to the structure of the external surface layer. The stereometric relations of agglutinated Candida cells are examined. The method is useful for the investigation of the topography of antigens composing the fungal cell wall by utilization of monospecific ferritin-labeled anti-Candida-sera in the direct immunoferritin test. The indirect immunferritin testndashas demonstrated in this studyndashenables to investigate the significance of antibodies against Candida antigens in the course of the hostparasite relationship during infectious processes.

Zusammenfassung: Ziel der Studie war die Pruning der Freisetzung von zwei verschiedenen Antimykotika aus sieben verschiedenen Salbengrundlagen, teils Grundlagen industriell konfektionierter Zubereitungen, teils DAB-Grundlagen. Die Pruning wurde vergleichend auf isolierter Schweinehaut, uber die bereits Erfahrungen anderer Autoren vorliegen, und auf einem selbst entwickelten Lipid-Agar vorgenommen, der Gelatine, Lecithin, synthetisches Schweineschmalz (Capryl/Caprin-/Stearinsaure Trigrycerid) und Hornmehl enthali Als Prufstanun wurde Trichophyton mentagrophytes 100/25 Hoechst verwendet. Vorlaufige Ergebnisse zeigen eine gute Korrelation zwischen den beiden Prufsystemen. Von zwei gepruften handelsublichen Antimykotika-Salben erwies sich ein Praparat als hinsichtlich der Wirkstoffliberation galenisch optimal formuliert; das weitere lies eine nicht-optimale Wirkstoffliberation erkennen. Die praktische Bedeutung dieser Befunde wird diskutiert. Summary: Purpose of this study was to test the release of two different antimycotics from seven different ointment bases. The bases were industrial preparations or ointment bases according to DAB (Deutsches Arzneibuch). The tests were made on samples of isolated pig skins, as described previously by other authors, and on a newly developed lipid-agar, which contains gelatine, lecithin, synthetic pig lard (Caprylic/Capric/Stearic Triglyceride) and hoof powder. Trichophyton mentagrophytes 100/25 Hoechst was used as test strain. The results show a good correlation between the two test-systems. One of two antimycotic preparations tested showed an optimal drug release, the other one was not satifactory in this respect. The practical use of these results is discussed.