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51.
J Lohi T Tani I Leivo A Linnala L Kangas RE Burgeson VP Lehto I Virtanen 《Canadian Metallurgical Quarterly》1996,68(3):364-371
We studied the expression of laminin (Ln) chains (alpha1-alpha3, beta1-beta3, gamma1) in human renal-cell carcinomas (RCC), papillary renal neoplasms (PRN) and oncocytomas, in RCC cell lines and their xenografts. In RCCs the basement membranes (BM) showed immunoreactivity for chains of Ln-1 (alpha1-beta1-gamma1). Only in well-differentiated RCCs could vessel BMs be distinguished from those of carcinoma cell islets. RCCs and oncocytomas also exhibited an abundant immunoreactivity for Ln beta2 chain in both vessel and tumor cell BMs, while Ln alpha2 chain was not seen in any renal tumors. In distinction from RCCs, PRNs presented a strong BM immunoreactivity for Ln alpha3 and beta3 chains and for Ln-5, as well as lack of Ln beta2 chain. A more variable reactivity for Ln-5 was seen in oncocytomas. As PRNs and oncocytomas have been suggested to originate from collecting ducts, it is notable that in normal human kidney, we could detect immunoreactivity for Ln-5 and its chains only in BM of the tubules of the loop of Henle. In immunoprecipitation experiments, an abundant production of Ln-1, but not of Ln-5, was seen in cultured RCC cells, while in xenografts of the same cells BM-confined immunoreactivity for both Ln-1 and Ln-5 was seen. Ln beta2 chain was produced by 2 of the 4 RCC cell lines in culture but was found only in 1 of the xenografted tumors. 相似文献
52.
Garmo OA Lehto NJ Zhang H Davison W Røyset O Steinnes E 《Environmental science & technology》2006,40(15):4754-4760
Sampling of metals with the technique of diffusive gradients in thin-films (DGT) depends on the rates of diffusion and on the kinetics of interconversion of the species present. In this study the discrimination between metal complexes with different dissociation kinetics is investigated. Samplers with differentthicknesses of diffusive and resin gels were deployed in solutions containing 10 microg/L of each metal in the lanthanide (Ln) series (except Pm) and 2.0 x 10(-6) M of the ligand quin2 at an ionic strength of 0.1 M (KNO3) and pH 7.0. Diffusion coefficients of Ln3+ ions and Ln-quin2 complexes were determined in a diffusion cell experiment. The equilibrium speciation of the metals was calculated from available stability constants. The sampling rate (mass/time) was highly dependent on the dissociation-rate constant of the complexes. For complexes with dissociation kinetics that appreciably limited the uptake, the sampling rate decreased significantly with increasing deployment times (12, 24, and 76 h) and was virtually independent of the thickness of the diffusive gel. Placing a layer of diffusive gel behind the resin did not influence the accumulation of Lns in the resin gel, but doubling the thickness of the layer containing resin increased the uptake, and more so for the Lns forming less labile complexes. The Lns forming more labile complexes were enriched in the outer layer of the resin, and there was a trend toward even distribution between the outer and deeper parts of the resin layer for the Lns forming less labile complexes. The measured DGT sampling rates (mass/ time) were reasonably well predicted by a dynamic model that used independently determined kinetic constants. This new knowledge of how metal complexes behave in the sampling process paves the way for using DGT to obtain in situ kinetic information in natural waters. 相似文献
53.
Arto O. Lehto Antti V. Räisänen 《Journal of Infrared, Millimeter and Terahertz Waves》1983,4(4):609-628
Using scaled model measurements at 2.5–12 GHz the embedding network of a 3 mm Schottky diode mixer has been developed. The noise performance of a cryogenic millimeter wave receiver was simulated by computer applying the developed equivalent circuit and diode parameters. The effects of impedance match at the fundamental frequency as well as at harmonic frequencies were studied. Also the effect of diode I-V-curve steepness was studied. The calculated results were compared with the experimental noise performance. 相似文献
54.
Maria Saarenhovi Pia Salo Mika Scheinin Jussi Lehto Zsófia Lovró Kirsti Tiihonen Markus J. Lehtinen Jouni Junnila Oliver Hasselwander Anneli Tarpila Olli T. Raitakari 《Nutrition journal》2017,16(1):73
Background
The primary aim of this study was to test the hypothesis that an orally ingested apple polyphenol extract rich in epicatechin and flavan-3-ol oligomers improves endothelium-dependent brachial artery flow-mediated vasodilatation (FMD) in volunteers with borderline hypertension. The secondary aim of the study was to test whether the investigational product would improve endothelium-independent nitrate-mediated vasodilatation (NMD).Methods
This was a single centre, repeated-dose, double-blind, placebo-controlled, crossover study in 60 otherwise healthy subjects (26 men, 34 women; aged 40-65 years) with borderline hypertension (blood pressure 130-139/85-89 mmHg) or unmedicated mild hypertension (blood pressure 140-165/90-95 mmHg). The subjects were randomised to receive placebo or the apple polyphenol extract to provide a daily dose of 100 mg epicatechin for 4 weeks, followed by a four to five-week wash-out period, and then 4 weeks intake of the product that they did not receive during the first treatment period. FMD and NMD of the left brachial artery were investigated with ultrasonography at the start and end of both treatment periods, and the per cent increase of the arterial diameter (FMD% and NMD%) was calculated.Results
With the apple extract treatment, a significant acute improvement was detected in the mean change of maximum FMD% at the first visit 1.16 (p = 0.04, 95% CI: 0.04; 2.28), last visit 1.37 (p = 0.02, 95% CI: 0.22; 2.52) and for both visits combined 1.29 (p < 0.01, 95% CI: 0.40; 2.18). However, such improvement was not statistically significant when apple extract was compared with placebo. The overall long-term effect of apple extract on FMD% was not different from placebo. No statistically significant differences between the apple extract and placebo treatments were observed for endothelium-independent NMD.Conclusions
A significant acute improvement in maximum FMD% with apple extract administration was found. However, superiority of apple extract over placebo was not statistically significant in our study subjects with borderline hypertension or mild hypertension. The study raised no safety concerns regarding the daily administration of an apple polyphenol extract rich in epicatechin.Trial registration
The trial is registered at http://clinicaltrials.gov (identifier: NCT01690676). Registered 25th May 2012.55.
A method is presented to synthesize wideband linear-phase finite-impulse-response (FIR) filters with a piecewise-polynomial-sinusoidal
impulse response. The method is based on merging the earlier synthesis scheme proposed by the authors to design piecewise-polynomial
filters with the method proposed by Chu and Burrus. The method uses an arbitrary number of separately generated center coefficients
instead of only one or none as used in the method by Chu–Burrus. The desired impulse response is created by using a parallel
connection of several filter branches and by adding an arbitrary number of center coefficients to form it. This method is
especially effective for designing Hilbert transformers by using Type 4 linear-phase FIR filters, where only real-valued multipliers
are needed in the implementation. The arithmetic complexity is proportional to the number of branches, the common polynomial
order for each branch, and the number of separate center coefficients. For other linear-phase FIR filter types the arithmetic
complexity depends additionally on the number of complex multipliers. Examples are given to illustrate the benefits of this
method compared to the frequency-response masking (FRM) technique with regard to reducing the number of coefficients as well
as arithmetic complexity. 相似文献
56.
Nieminen TT Vihavainen E Paloranta A Lehto J Paulin L Auvinen P Solismaa M Björkroth KJ 《International journal of food microbiology》2011,144(3):360-366
Characterization of psychrotrophic lactic acid bacteria (LAB) and Brochothrix thermosphacta communities is needed to understand the microbial ecology of spoilage of modified atmosphere-packed (MAP) meats. To overcome the limitations of the currently used methods for the characterization of psychrotrophic bacterial communities in meat, we developed a culture-independent, 16S rRNA gene-targeted terminal restriction fragment length polymorphism (T-RFLP) method. An identification library consisting of 100 Gram-positive and 30 Gram-negative meat-associated bacterial strains was set up to identify the terminal restriction fragments derived from the communities. The taxonomic resolution level of the T-RFLP method was in between genus and species within the investigated LAB strains and within family and genus within the investigated Gram-negative strains. The established library was applied to identify the members of bacterial communities in MAP minced meat at the end of the shelf life. The T-RFLP results and plate counts on Man-Rogosa-Sharpe, Violet Red Bile Glucose, and Streptomycin sulfate thallium acetate actidione agars indicated that LAB and B. thermosphacta predominated in meat. The bacterial taxa associated with the T-RFLP results were compared to those identified among plate-grown LAB isolates by numerical ribopattern analysis. Both methods agreed that Leuconostoc spp. and Carnobacterium spp. prevailed in the LAB community in minced meat followed by Lactobacillus algidus, Lactococcus spp. and Weissella spp. Colony identification revealed that Leuconostoc gasicomitatum, L. gelidum, Carnobacterium divergens and C. maltaromaticum were the predominant LAB species. The T-RFLP results were shown to correlate with viable counts of Leuconostoc spp. and B. thermosphacta. The T-RFLP method was found to be a useful tool enabling rapid and high-throughput characterization of psychrotrophic bacteria prevailing in MAP meat. 相似文献
57.
58.
Brent J. Bellinger Terri M. Jicha LaRae P. Lehto Lindsey R. Seifert-Monson David W. Bolgrien Matthew A. Starry Theodore R. Angradi Mark S. Pearson Colleen Elonen Brian H. Hill 《Journal of Great Lakes research》2014
Inorganic nitrogen (N) transformations and removal in aquatic sediments are microbially mediated, and rates influence N-transport. In this study we related physicochemical properties of a large Great Lakes embayment, the St. Louis River Estuary (SLRE) of western Lake Superior, to sediment N-transformation rates. We tested for associations among rates and N-inputs, vegetation biomass, and temperature. We measured rates of nitrification (NIT), unamended base denitrification (DeNIT), and potential denitrification [denitrifying enzyme activity (DEA)] in 2011 and 2012 across spatial and depth zones. In vegetated habitats, NIT and DeNIT rates were highest in deep (ca. 2 m) water (249 and 2111 mg N m− 2 d− 1, respectively) and in the upper and lower reaches of the SLRE (> 126 and 274 mg N m− 2 d− 1, respectively). Rates of DEA were similar among zones. In 2012, NIT, DeNIT, and DEA rates were highest in July, May, and June, respectively. System-wide, we observed highest NIT (223 and 287 mg N m− 2 d− 1) and DeNIT (77 and 64 mg N m− 2 d− 1) rates in the harbor and from deep water, respectively. Amendment with NO3− enhanced DeNIT rates more than carbon amendment; however, DeNIT and NIT rates were inversely related, suggesting the two processes are decoupled in sediments. Average proportion of N2O released during DEA (23–54%) was greater than from DeNIT (0–41%). Nitrogen cycling rates were spatially and temporally variable, but we modeled how alterations to water depth and N-inputs may impact DeNIT rates. A large flood occurred in 2012 which temporarily altered water chemistry and sediment nitrogen cycling. 相似文献
59.
J. I. Villegas N. Kumar T. Heikkilä V.-P. Lehto T. Salmi D. Yu. Murzin 《Topics in Catalysis》2007,45(1-4):187-190
New restrictions on gasoline in some part of the world implies that oxygenates such as MTBE and aromatics should be replaced
by other high-octane components. The dimerization of 1-butene, which is a step in the production of “Green” gasoline, is evaluated
under liquid phase reaction conditions over acidic Beta zeolites synthesized with different synthesis time. There are substantial
differences between Beta zeolites obtained at synthesis times 96 and 240 h leading to different physico-chemical properties
and, furthermore, catalytic performances. More acidic Beta zeolites lead to higher yields to light olefins while less acidic
samples produce more oligomers, i.e. C12–C14 fraction. Interestingly, it was also observed that strong acid sites catalyze cracking reactions, while the weak ones, oligomerization. 相似文献
60.
Ala-Laurinaho J. Hirvonen T. Piironen P. Lehto A. Tuovinen J. Raisanen A.V. Frisk U. 《Antennas and Propagation, IEEE Transactions on》2001,49(9):1264-1270
Development work of a 119 GHz compact antenna test range (CATR), based on a 2.4 m×2.0 m hologram and its application on the Odin telescope tests are described. The hologram element comprises seven parts, which are fabricated using silk-screen printing techniques. Comparison between the theoretical and the measured quiet-zone fields of the hologram CATR is made, which demonstrates the correctness of the analysis method and also the importance of high quality physical joints between the hologram parts. The CATR has been successfully used in the measurement of a 1.1-m offset reflector antenna onboard the Odin spacecraft. The measured and calculated antenna radiation patterns are in good agreement in the main beam region. The effects of the imperfections in the quiet-zone field and in the aperture field of the antenna on the measurement results are simulated 相似文献