Impact of High-Molecular-Weight Hyaluronic Acid on Gene Expression in Rabbit Achilles Tenocytes In Vitro

(1) Background: Surgical tendon repair often leads to adhesion formation, leading to joint stiffness and a reduced range of motion. Tubular implants set around sutured tendons might help to reduce peritendinous adhesions. The lubricant hyaluronic acid (HA) is a viable option for optimizing such tubes with the goal of further enhancing the anti-adhesive effect. As the implant degrades over time and diffusion is presumed, the impact of HA on tendon cells is important to know. (2) Methods: A culture medium of rabbit Achilles tenocytes was supplemented with high-molecular-weight (HMW) HA and the growth curves of the cells were assessed. Additionally, after 3, 7 and 14 days, the gene expression of several markers was analyzed for matrix assembly, tendon differentiation, fibrosis, proliferation, matrix remodeling, pro-inflammation and resolution. (3) Results: The addition of HA decreased matrix marker genes, downregulated the fibrosis marker α-SMA for a short time and slightly increased the matrix-remodeling gene MMP-2. Of the pro-inflammatory marker genes, only IL-6 was significantly upregulated. IL-6 has to be kept in check, although IL-6 is also needed for a proper initial inflammation and efficient resolution. (4) Conclusions: The observed effects in vitro support the intended anti-adhesion effect and therefore, the use of HMW HA is promising as a biodegradable implant for tendon repair.     

Improving the Design of Greek Hollow Clay Bricks

The hollow clay brick is the typical building unit that is employed not only over the whole Greece but also in many other Mediterranean countries. Nevertheless, its design is completely empirical. In this study, the design of the hollow clay brick is analyzed by employing a finite element package. To carry out this analysis, the thermal conductivity of the solid clay is measured by the transient hot-wire technique. As a consequence of the analysis, an improvement of 24 % in the design of the hollow clay brick is proposed.     

Two-dimensional linear-combination model fitting of magnetic resonance spectra to define the macromolecule baseline using FiTAID,a Fitting Tool for Arrays of Interrelated Datasets

Object  

To propose the determination of the macromolecular baseline (MMBL) in clinical 1H MR spectra based on T₁ and T₂ differentiation using 2D fitting in FiTAID, a general Fitting Tool for Arrays of Interrelated Datasets.     

New sources of resistance to Acanthoscelides obtectus (Say) and Zabrotes subfasciatus Boheman (Coleoptera: Bruchidae) in mature seeds of five species of Phaseolus

The importance of carefully applied bioassay techniques is highlighted for identifying resistance of Phaseolus spp to the bruchids Acanthoscelides obtectus (Say) and Zabrotes subfasciatus Boheman. Two potential sources of resistance are identified amongst the varieties of P. vulgaris screened. In one the presence of a lectin-like protein (LLP) was identified, which has previously been associated with resistance, while in the other, resistance may be linked to the presence of a novel protein, similar to but not the same as LLP. The use of anti-LLP antibodies are suggested as a useful tool for distinguishing between resistant and susceptible varieties. Five varieties of P. lunatus and six of P. acutifolius are shown to be resistant to A. obtectus, and the potential is recognized for transferring resistant genes to P. vulgaris via interspecific crosses.     

Direct Determination of Energy Band Alignments of Ni/Al2O3/GaN MOS Structures Using Internal Photoemission Spectroscopy

The energy band alignments of Ni/Al₂O₃/GaN heterostructures have been explored by internal photoemission (IPE) and capacitance–voltage (CV) measurements. By performing IPE measurements at both reverse- and forward-bias conditions, the Ni/Al₂O₃ Schottky barrier is found to be 2.9 ± 0.1 eV with the presence of a strong image force lowering effect, while the Al₂O₃/GaN conduction-band offset is determined to be 2.2 ± 0.1 eV and is insensitive to oxide electrical field. CV-based flat-band voltage analysis has further been performed on samples with different oxide thicknesses, not only confirming the IPE-measured band alignment but also revealing the presence of 3.0 × 10¹² cm^-2 net positive charge at the Al₂O₃/GaN interface.     

Long time reliability study of soldered flip chips on flexible substrates

Due to the requirements of new light, mobile, small and multifunctional electronic products the density of electronic packages continues to increase. Especially in medical electronics like pace makers the minimisation of the whole product size is an important factor. So flip chip technology becomes more and more attractive to reduce the height of an electronic package. At the same time the use of flexible and foldable substrates offers the possibility to create complex electronic devices with a very high density. In terms of human health the reliability of electronic products in medical applications has top priority.In this work flip chip interconnections to a flexible substrate are studied with regard to long time reliability. Test chips and substrates have been designed to give the possibility for electrical measurements. Solder was applied using conventional stencil printing method. The flip chip contacts on flexible substrates were created in a reflow process and underfilled subsequently.The assemblies have been tested according to JEDEC level 3. The focus in this paper is the long time reliability up to 10,000 h in thermal ageing at 125 °C and temperature/humidity testing at 85 °C/85% relative humidity as well as thermal cycling (0 °C/+100 °C) up to 5000 cycles. Daisy chain and four point Kelvin resistances have been measured to characterise the interconnections and monitor degradation effects.The failures have been analysed in terms of metallurgical investigations of formation and growing of intermetallic phases between underbump metallisation, solder bumps and conductor lines. CSAM was used to detect delaminations at the interfaces underfiller/chip and underfiller/substrate respectively.     

Ligand‐Free Synthesis of Aluminum‐Doped Zinc Oxide Nanocrystals and their Use as Optical Spacers in Color‐Tuned Highly Efficient Organic Solar Cells

The color of polymer solar cells using an opaque electrode is given by the reflected light, which depends on the composition and thickness of each layer of the device. Metal‐oxide‐based optical spacers are intensively studied in polymer solar cells aiming to optimize the light absorption. However, the low conductivity of materials such as ZnO and TiO₂ limits the thickness of such optical spacers to tenths of nanometers. A novel synthesis route of cluster‐free Al‐doped ZnO (AZO) nanocrystals (NCs) is presented for solution processing of highly conductive layers without the need of temperature annealing, including thick optical spacers on top of polymer blends. The processing of 80 nm thick optical spacers based on AZO nanocrystal solutions on top of 200 nm thick polymer blend layer is demonstrated leading to improved photocurrent density of 17% compared to solar cells using standard active layers of 90 nm in combination with thin ZnO‐based optical spacers. These AZO NCs also open new opportunities for the processing of high‐efficiency color tuned solar cells. For the first time, it is shown that applying solution‐processed thick optical spacer with polymer blends of different thicknesses can process solar cells of similar efficiency over 7% but of different colors.     

A review and assessment of numerical shade sorting methods

The properties of current shade sorting geometries are evaluated on a mathematically generated, spherical population of normally distributed data points. The results compare well with those obtained from preuiously cited populations of textile production goods. Thefixed-grid geometries (cubic, rhombic dodecahedra1 and truncated octahedral) are not as efficient in terms of the numbers and uniformity of shade sorting groups as the grid-free spherical clusters employed by Clemson Color Clustering (CCC).     

Dihydroazulene Photoswitch Operating in Sequential Tunneling Regime: Synthesis and Single‐Molecule Junction Studies

Molecular switches play a central role for the development of molecular electronics. In this work it is demonstrated that the reproducibility and robustness of a single‐molecule dihydroazulene (DHA)/vinylheptafulvene (VHF) switch can be remarkably enhanced if the switching kernel is weakly coupled to electrodes so that the electron transport goes by sequential tunneling. To assure weak coupling, the DHA switching kernel is modified by incorporating p‐MeSC₆H₄ end‐groups. Molecules are prepared by Suzuki cross‐couplings on suitable halogenated derivatives of DHA. The synthesis presents an expansion of our previously reported bromination–elimination–cross‐coupling protocol for functionalization of the DHA core. For all new derivatives the kinetics of DHA/VHF transition has been thoroughly studied in solution. The kinetics reveals the effect of sulfur end‐groups on the thermal ring‐closure of VHF. One derivative, incorporating a p‐MeSC₆H₄ anchoring group in one end, has been placed in a silver nanogap. Conductance measurements justify that transport through both DHA (high resistivity) and VHF (low resistivity) forms goes by sequential tunneling. The switching is fairly reversible and reenterable; after more than 20 “ON‐OFF” switchings, both DHA and VHF forms are still recognizable, albeit noticeably different from the original states.     

Investigation of physical and chemical property changes of ultra low-κ SiOCH in aspect of cleaning and chemical repair processes

The physical and chemical property changes of chemical vapor deposited ultra low-κ (ULK) SiOCH dielectric films due to different post ash treatments were studied by Auger electron spectroscopy, ellipsometric porosimetry and surface free energy evaluation. Structural changes in the ULK layer with respect to the carbon content were analyzed. Using a downstream and a reactive ion etch process for photo resist removal a reduction of carbon was observed. For different plasma gas chemistries the pore size reduction depends first on the process condition (downstream or reactive ion etch) and then on the gas. Differences in the pore size then also influence the amount of carbon depletion besides the influence of the gases used for photo resist processes. The damage at the surfaces was characterized by contact angle measurements providing both the polar and dispersive part of the surface free energy. The wettability of different solvents and repair chemicals was classified calculating their surface free energies and comparing those energies with the surface free energies of modified ULK surface. It is shown that especially reducing gases provide a surface free energy with a higher dispersive part compared to oxidative plasma treatments. Furthermore it was found that the wettability of repair chemicals and solvents strongly changes for reductive based strip processes with plasma exposure time, since a high variation of the surface free energy occur.