Combining Electrochemical Impedance Spectroscopy and Surface Plasmon Resonance into one Simultaneous Read-Out System for the Detection of Surface Interactions

In this article we describe the integration of impedance spectroscopy (EIS) and surface plasmon resonance (SPR) into one surface analytic device. A polydimethylsiloxane (PDMS) flow cell is created, matching the dimensions of a commercially available sensor chip used for SPR measurements. This flow cell allowed simultaneous measurements between an EIS and a SPR setup. After a successful integration, a proof of principle study was conducted to investigate any signs of interference between the two systems during a measurement. The flow cell was rinsed with 10 mM Tris-HCl and 1× PBS buffer in an alternating manner, while impedance and shifts of the resonance angle were monitored. After achieving a successful proof of principle, a usability test was conducted. It was assessed whether simultaneous detection occurred when: (i) Protein A is adsorbed to the gold surface of the chip; (ii) The non-occupied zone is blocked with BSA molecules and (iii) IgG1 is bound to the Protein A. The results indicate a successful merge between SPR and EIS.status: publishe

Design and Synthesis of Building Blocks for PPII-Helix Secondary-Structure Mimetics: A Stereoselective Entry to 4-Substituted 5-Vinylprolines (vol 2018, pg 455, 2018)

In the course of our studies towards the synthesis of proline-based secondary-structure mimetics, we developed a straightforward methodology for the diastereoselective preparation of 4-alkyl-5-vinyl-substituted proline derivatives. Starting from N-Boc-protected tert-butyl pyroglutamate, -alkylation, lactam reduction and acid-catalyzed methanolysis afforded 4-alkyl-5-methoxyproline derivatives. After BF3-induced formation of an N-acyl-iminium intermediate, the introduction of the 5-vinyl side chain was achieved with high diastereoselectivity by using vinylmagnesium bromide in the presence of AlCl3 or CuBrSMe2 to afford either the cis- or the trans-product, respectively. The utility of the method was demonstrated in the rapid and efficient construction of new diproline mimetics rigidified in a polyproline-type II helix (PPII) conformation

Effect of Oenothera odorata Root Extract on Microgravity and Disuse-Induced Muscle Atrophy

Muscle atrophy, a reduction of muscle mass, strength, and volume, results from reduced muscle use and plays a key role in various muscular diseases. In the microgravity environment of space especially, muscle atrophy is induced by muscle inactivity. Exposure to microgravity induces muscle atrophy through several biological effects, including associations with reactive oxygen species (ROS). This study used 3D-clinostat to investigate muscle atrophy caused by oxidative stress in vitro, and sciatic denervation was used to investigate muscle atrophy in vivo. We assessed the effect of Oenothera odorata root extract (EVP) on muscle atrophy. EVP helped recover cell viability in C2C12 myoblasts exposed to microgravity for 24 h and delayed muscle atrophy in sciatic denervated mice. However, the expressions of HSP70, SOD1, and ceramide in microgravity-exposed C2C12 myoblasts and in sciatic denervated mice were either decreased or completely inhibited. These results suggested that EVP can be expected to have a positive effect on muscle atrophy by disuse and microgravity. In addition, EVP helped characterize the antioxidant function in muscle atrophy

Effects of Diamond Nanoparticles Immobilisation on the Surface of Yeast Cells: A Phenomenological Study

An interesting development of biotechnology has linked microbial cell immobilisation with nanoparticles. The main task of our research was to reveal the possible influences of differently electrically charged diamond nanoparticles upon physiological characteristics of the yeast Saccharomyces cerevisiae. It was revealed that the adverse impact of these nanoparticles can manifest not only against prokaryotes, but also against eukaryotic yeast cells. However, the obtained results also indicate that it is possible to reduce and, most likely, completely eliminate the dangerous effects of nanoparticles to cells by using special physical approaches. Comparison of non-arylated and arylated nanoparticles showed that in terms of changes in the physiological activity of cells, which are important to biotechnology and biomedicine, the selection of certain nanoparticles (non-arylated or arylated) may be necessary in each specific case, depending on the purpose of their use

Synthesis and characterization of carbon nanowalls on different substrates by radio frequency plasma enhanced chemical vapor deposition

A radio frequency plasma enhanced chemical vapor deposition system was used for the successful growth of thin vertical carbon nanowalls, also known as vertical graphene, on various substrates. Transmission electron microscopy studies confirmed the presence of vertical graphene walls, which are tapered, typically consisting of 10 layers at the base tapering off to 2 or 3 layers at the top. The sides of the walls are facetted at quantized angles of 30 and the facetted sides are usually seamless. Growth occurs at the top open edge which is not facetted. Hydrogen induced etching allows for nucleation of branch walls apparently involving a carbon onion-like structure at the root base. Characterization by a superconducting quantum interference device showed magnetic hysteresis loops and weak ferromagnetic responses from the samples at room temperature and below. Temperature dependence of the magnetization revealed a magnetic phase transition around T = 50 K highlighting the coexistence of antiferromagnetic interactions as well as ferromagnetic order.147491sciescopu

Sediment-filled karst depressions and riyad - key archaeological environments of south Qatar

Systematic archaeological exploration of southern Qatar started in the 1950s. However, detailed local and regional data on climatic fluctuations and landscape changes during the Holocene, pivotal for understanding and reconstructing human-environment interactions, are still lacking. This contribution provides an overview on the variability of geomorphic environments of southern Qatar with a focus on depression landforms, which reveal a rich archaeological heritage ranging from Palaeolithic(?) and Early Neolithic times to the Modern era. Based on a detailed geomorphic mapping campaign, sediment cores and optically stimulated luminescence data, the dynamics of riyad (singular rawdha; shallow, small-scale, sediment-filled karst depressions clustering in the central southern peninsula) and the larger-scale Asaila depression near the western coast are studied in order to put archaeological discoveries into a wider environmental context. Geomorphic mapping of the Asaila basin shows a much greater geomorphic variability than documented in literature so far with relict signs of surface runoff. An 8 m long sediment core taken in the sabkha-type sand flats of the western basin reveals a continuous dominance of aeolian morphodynamics during the early to mid-Holocene. Mounds preserved by evaporite horizons representing capillarites originally grown in the vadose zone are a clear sign of groundwater-level drop after the sea-level highstand ca. 6000-4500 years ago. Deflation followed the lowering of the Stokes surface, leaving mounds where the relict capillarites were able to fixate and preserve the palaeo-surface. Abundant archaeological evidence of Early and Middle Neolithic occupation - the latter with a clear focus inside the central Asaila basin - indicate more favourable living conditions than today. In contrast, the sediment record of the investigated riyad in the south is very shallow, younger and controlled by surface discharge, deflation and the constantly diminishing barchan dune cover in Qatar over the Middle and Late Holocene. The young age of the infill (ca. 1500 to 2000 years) explains the absence of findings older than the Late Islamic period. Indicators of current net deflation may relate to a decrease in surface runoff and sediment supply only in recent decades to centuries. In the future, geophysical prospection of the riyad may help to locate thicker sedimentary archives and the analysis of grain size distribution, micromorphology, phytoliths or even pollen spectra may enhance our understanding of the interplay of regional environmental changes and cultural history

Effect of Chemically Modified Carbon-Coated Iron Nanoparticles on the Structure of Human Atherosclerotic Plaques Ex Vivo and on Adipose Tissue in Chronic Experiment In Vivo

The high mortality rate caused by atherosclerosis makes it necessary to constantly search for new and better treatments. In previous reports, chemically modified carbon-coated iron nanoparticles (Fe@C NPs) have been demonstrated a high biocompatibility and promising anti-plaque properties. To further investigate these effects, the interaction of these nanoparticles with the adipose tissue of Wistar rats (in vivo) and human atherosclerotic plaques (ex vivo) was studied. For the in vivo study, cobalt–chromium (CoCr) alloy tubes, which are used for coronary stent manufacturing, were prepared with a coating of polylactic acid (PLA) which contained either modified or non-modified Fe@C NPs in a 5% by weight concentration. The tubes were implanted into an area of subcutaneous fat in Wistar rats, where changes in the histological structure and functional properties of the surrounding tissue were observed in the case of coatings modified with Fe@C NPs. For the ex vivo study, freshly explanted human atherosclerotic plaques were treated in the physiological solution with doses of modified Fe@C NPs, with mass equal to 5% or 25% relative to the plaques. This treatment resulted in the release of cholesterol-like compounds from the surface of the plaques into the solution, thus proving a pronounced destructive effect on the plaque structure. Chemically modified Fe@C NPs, when used as an anti-atherosclerosis agent, were able to activate the activity of macrophages, which could lead to the destruction of atherosclerotic plaques structures. These findings could prove the fabrication of next-generation vascular stents with built-in anti-atherosclerotic agents

Enhanced properties of poly(ε-caprolactone)/polyvinylpyrrolidone electrospun scaffolds fabricated using 1,1,1,3,3,3-hexafluoro-2-propanol

Poly(ε-caprolactone)/polyvinylpyrrolidone (PCL/PVP) scaffolds with various composition were fabricated from 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) solution using the same electrospinning parameters in order to reveal the effect of polymer ratio on the material properties. The obtained materials were characterized using scanning electron microscopy, contact angle measurements, X-ray diffraction, Fourier-transformed infrared spectroscopy, and tensile testing. The strengthening effect of PVP was observed: Young modulus of PCL/PVP scaffold with 50/50 polymer ratio was found at 105.4 ± 8.4 MPa which is six times higher comparing to those of PCL scaffold. PVP-containing scaffolds were extremely hydrophilic with PVP concentration of 5 wt% (vs. 25 wt% in previous reports) leading to full wetting of the material. in vitro studies showed an improved viability of HeLa cells cultured with the composites containing higher concentrations of PVP. Owing to the application of HFIP, PCL-based materials were loaded with cyclophosphamide for the first time and the PVP-containing materials demonstrated the intensified initial release of the model compound. Utilizing HFIP for the fabrication of PCL/PVP scaffolds significantly widens their application for drug delivery systems due to a good solubility of proteins, drugs, and other biologically active compounds in this solvent

Tricuspid valve insufficiency Position paper of the DGK

In the majority of cases patients with high-grade tricuspid valve insufficiency (TI) represent a high-risk population and the treatment is particularly complex. Therefore, selection of an appropriate therapeutic pathway for affected individuals first requires precise characterization of the genesis of the vitium. This includes transthoracic and transesophageal echocardiography, right heart and left heart catheterization and additional imaging by CT and MRI as needed. Treatment requires interdisciplinary discussion, including optimization of drug treatment for left heart failure, discussion of antiarrhythmic treatment procedures for atrial genesis of TI, exclusion of pathologies of the heart requiring surgical treatment, and exclusion of indications for targeted therapy for pulmonary arterial hypertension (PAH). Interventional treatment now has an important place, particularly because of the very frequent comorbidity of patients. The 2021 ESC guidelines recommended catheter-based reconstruction for the first time. The still limited experience with this complex form of treatment, the lack of randomized prospective studies on its effectiveness, and challenges in periprocedural imaging have prompted the DGK to formulate these recommendations in anticipation of concrete criteria for future center certification when providing a program for interventional treatment of tricuspid regurgitation. This paper is intended to contribute to the provision of this important treatment to patients in Germany under the premise of the best possible quality