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31.
Katja Myllymaa Sami Myllymaa Hannu Korhonen Mikko J. Lammi Hanna Saarenpää Mika Suvanto Tapani A. Pakkanen Virpi Tiitu Reijo Lappalainen 《Journal of materials science. Materials in medicine》2009,20(11):2337-2347
The adhesion and contact guidance of human primary osteogenic sarcoma cells (Saos-2) were characterized on smooth, microstructured
(MST) and micro- and nano-structured (MNST) polypropylene (PP) and on the same samples with a silicon-doped carbon nitride
(C3N4-Si) coating. Injection molding was used to pattern the PP surfaces and the coating was obtained by using ultra-short pulsed
laser deposition (USPLD). Surfaces were characterized using atomic force microscopy and surface energy components were calculated
according to the Owens-Wendt model. The results showed C3N4-Si coated surfaces to be significantly more hydrophilic than uncoated ones. In addition, there were 86% more cells in the
smooth C3N4-Si coated PP compared to smooth uncoated PP and 551%/476% more cells with MST/MNST C3N4-Si coated PP than could be obtained with MST/MNST uncoated PP. Thus the adhesion, spreading and contact guidance of osteoblast-like
cells was effectively improved by combining surface texturing and deposition of osteocompatible C3N4-Si coating. 相似文献
32.
Heat transfer and pressure drop of a fin-and-tube heat exchanger are studied by taking into account the conjugated heat transfer between the flow and the fin. The temperature distribution of the fin is calculated in respect to the convective heat transfer of the air flowing through the tube bank channel. Contemporary enhancement methods emphasize the importance of local turbulence augmentation which effects the convective heat transfer. In this paper, the importance of conjugated heat transfer, where the temperature of the flow and fin are coupled together is emphasized and compared with a constant surface temperature boundary condition simulation and experiment, which are found in the literature. 相似文献
33.
Effects of Juice Matrix and Pasteurization on Stability of Black Currant Anthocyanins during Storage 下载免费PDF全文
Gary Dobson Gordon J. McDougall Derek Stewart Miguel Ángel Cubero Reijo O. Karjalainen 《Journal of food science》2017,82(1):44-52
The effects of juice matrix and pasteurization on the stability of total phenols and especially total and individual anthocyanins were examined in black currant (BC) juice and mixtures with apple, persimmon, and peach juices at 4 °C and 20 °C. Total phenol content decreased in all juices at both temperatures but there was a trend to lower levels in unpasteurized over pasteurized juices. Differences in the decline of total anthocyanins between pasteurized and unpasteurized juices varied according to the juice type and the storage temperature. At 4 °C storage, anthocyanins declined in all juices according to pseudo 1st‐order kinetics and there were only small differences in the rates between pasteurized and unpasteurized juices. However, at 20 °C, although pasteurized and unpasteurized BC juices and pasteurized mixed juices followed pseudo 1st‐order kinetics, there was a different pattern in unpasteurized mixed juices; a rapid initial decline was followed by a slowing down. The effect of the added juice on anthocyanin decline was also different at either temperature. At 4 °C, the anthocyanins decreased faster in mixed juices than BC juice alone, but at 20 °C, at least in pasteurized mixed juices, the decline was similar or even slower than in BC juice; there were only small differences among the 3 mixed juices. At 20 °C, in pasteurized and unpasteurized BC juices, the rate of decrease was essentially the same for all 4 individual anthocyanins but in the mixed juices the 2 glucosides decreased significantly faster than the 2 rutinosides. 相似文献
34.
Niina MM Saviranta Riitta Julkunen‐Tiitto Elina Oksanen Reijo O Karjalainen 《Journal of the science of food and agriculture》2010,90(3):418-423
BACKGROUND: Phenolic compounds have recently received considerable attention for their ability to protect plant and human cells from oxidative stress‐induced damage. Red clover (Trifolium pratense L.) is a rich source of isoflavonoids with multiple potential protective functions. The aim of this study was to identify and characterise phenolic compounds in red clover roots by high‐performance liquid chromatography and mass spectrometry and to study the effects of stress factors and growth stage on root phenolics. RESULTS: A total of 28 phenolic compounds were tentatively identified in red clover roots. The most abundant phenolics in pot‐grown roots were formononetin glycoside malonate (G‐M) (1.51–4.26 mg g?1), formononetin (2.21–3.57 mg g?1) and biochanin A (1.73–2.17 mg g?1), whereas field‐grown roots were rich in formononetin‐G‐M (3.90–4.27 mg g?1), maackiain‐G‐M (2.35–3.02 mg g?1) and pseudobaptigenin‐G‐M (1.80–2.58 mg g?1). Concentrations were affected by the growth stage. Ozone exposure slightly affected the total phenolic content in roots and also had minor effects on individual compounds. CONCLUSION: Elevated ozone, cultivation regime and growth stage affected the levels of phenolics in red clover roots, suggesting sensitivity of root phenolics to biotic and abiotic stress conditions. The high levels of phenolics found in roots even in late autumn may be utilised in many applications. Copyright © 2009 Society of Chemical Industry 相似文献
35.
Non‐targeted metabolite profiling highlights the potential of strawberry leaves as a resource for specific bioactive compounds 下载免费PDF全文
36.
Ion plating and plasma nitriding at low pressures with a glow discharge supported by a hot electron-emitting filament are studied. The properties and applications of titanium nitride coatings are discussed. Examples of their use for wear reduction in cutting are presented and their frictional properties are investigated. The triode technique is also applied in plasma nitriding and the effects on nitrogen penetration are discussed. In a steel with low contents of carbon and chromium considerable increase in the thickness of the diffusion zone is obtained by using the triode system. Further, it is shown that plasma nitriding can be combined with subsequent ion plating in order to prevent abrasive wear. 相似文献
37.
Sulonen K. Suvikunnas P. Vuokko L. Kivinen J. Vainikainen P. 《Selected Areas in Communications, IEEE Journal on》2003,21(5):703-712
This paper presents the results achieved with a dual-polarized multiple-input multiple-output (MIMO) measurement system in the 2 GHz range. Results from continuous measurement routes were used in evaluating and comparing different MIMO antenna configurations. Different pattern and polarization diversity possibilities were studied using two methods: elements were selected from the antenna arrays used in measurements, and as another option, in the mobile station the incident waves were estimated and used in different dipole antenna arrays. The capacity limit seems to be higher in an indoor picocell than in an outdoor microcell environment. At the mobile station, directive elements result in 35% higher average capacities than those of the omnidirectional elements; however, the capacity of the directive elements also depends on the azimuth direction of arrival of the incident field. Dual-polarized antenna configurations have approximately 14% higher capacities than copolarized configurations. Increasing the number of mobile antenna elements increases the capacity in those environments where the angular spread of the incident field is large. Increasing the distance between elements at the fixed station increases the capacity - especially in microcells where signals arrive from specific directions. 相似文献
38.
Soininen A Levon J Katsikogianni M Myllymaa K Lappalainen R Konttinen YT Kinnari TJ Tiainen VM Missirlis Y 《Journal of materials science. Materials in medicine》2011,22(3):629-636
This study compares the ability of selected materials to inhibit adhesion of two bacterial strains commonly implicated in
implant-related infections. These two strains are Staphylococcus aureus (S-15981) and Staphylococcus epidermidis (ATCC 35984). In experiments we tested six different materials, three conventional implant metals: titanium, tantalum and
chromium, and three diamond-like carbon (DLC) coatings: DLC, DLC–polydimethylsiloxane hybrid (DLC–PDMS-h) and DLC–polytetrafluoroethylene
hybrid (DLC–PTFE-h) coatings. DLC coating represents extremely hard material whereas DLC hybrids represent novel nanocomposite
coatings. The two DLC polymer hybrid films were chosen for testing due to their hardness, corrosion resistance and extremely
good non-stick (hydrophobic and oleophobic) properties. Bacterial adhesion assay tests were performed under dynamic flow conditions
by using parallel plate flow chambers (PPFC). The results show that adhesion of S. aureus to DLC–PTFE-h and to tantalum was significantly (P < 0.05) lower than to DLC–PDMS-h (0.671 ± 0.001 × 107/cm2 and 0.751 ± 0.002 × 107/cm2 vs. 1.055 ± 0.002 × 107/cm2, respectively). No significant differences were detected between other tested materials. Hence DLC–PTFE-h coating showed
as low susceptibility to S. aureus adhesion as all the tested conventional implant metals. The adherence of S. epidermidis to biomaterials was not significantly (P < 0.05) different between the materials tested. This suggests that DLC–PTFE-h films could be used as a biomaterial coating
without increasing the risk of implant-related infections. 相似文献
39.
Stefan Grönroos Kristian Nybom Jerker Björkqvist Juhani Hallio Jani Auranen Reijo Ekman 《Journal of Signal Processing Systems》2016,85(1):5-21
Lattice Reduction aided MIMO detectors have been demonstrated to offer a promising gain by providing near-optimal performance. This paper presents a C-programmable ASIP baseband processor, for near-optimal MIMO detection targeting a 4×4 LTE system. The detector supports multiple MIMO detection modes, with both hard and soft output. In order to improve implementation efficiency, the previously reported MIMO detection algorithm Multi-Tree Selective Spanning Detector (MTSS) is modified to use orthogonal real-valued decomposition (ORVD). Afterwards, a low-complexity log-likelihood-ratio (LLR) improvement technique called counter-ML bit-flipping algorithm is proposed. The proposed LLR generation algorithm has been designed to take advantage of MTSS, by maximizing the reuse of computations. Performance of the proposed solution can be tuned ranging from SIC to near-ML to near-MAP. The baseband processor is designed using 40 nm process technology with an equivalent gate-count (GE) of 68.41 kGE. Operating at 600 MHz for a 4×4 QAM-64 LTE system, the processor delivers peak-throughputs of 3.6 Gbps and 2.05 Gbps in case of hard and soft output MIMO detection, with 13.03 mW and 22.99 mW respective power consumption. The corresponding energy efficiency is 3.61 pJ/bit and 11.17 pJ/bit. In terms of energy efficiency, the proposed reconfigurable solution is comparable to recently reported ASIC MIMO detectors, while providing multiple-modes of operation and the flexilibility of C-programming. 相似文献
40.
Markku Tiitta Laura Tomppo Helena Järnström Mia Löija Tapio Laakso Anni Harju Martti Venäläinen Hanna Iitti Leena Paajanen Pekka Saranpää Reijo Lappalainen Hannu Viitanen 《Holz als Roh- und Werkstoff》2009,67(2):151-158
Scots pine heartwood specimens were exposed to mould in controlled humid atmosphere (RH 95%, T?=20 °C) and the responses of electrical impedance and Fourier transform infrared spectroscopy (EIS and FTIR) methods were studied. The concentration of methanol soluble heartwood extractives and the emission of volatile organic compounds (VOC) were determined from the parallel samples. Results show that the spectral responses and VOC emissions were related to the mould development. According to this study, VOC emissions might be used for discriminating mould susceptible and resistant samples. FTIR spectra showed that the relation of amide (1655 cm-1) and carbonyl peaks (1736 cm-1) was significantly affected by mould. In the EIS analyses, there also were electrical parameters, which were significantly affected by mould. In conclusion, both spectral methods hold potential for non-destructive mould detection and monitoring of mould development. 相似文献