Search

Research over the last ten years has resulted in attempts toward single-chip CMOS RF circuits for Bluetooth, global positioning system, digital enhanced cordless telecommunications and cellular applications. An overview of the use of CMOS for low-cost integration of a high-end cellular RF transceiver front-end is presented. Some fundamental pitfalls and limitations of RF CMOS are discussed. To circumvent these obstacles, the choice of transceiver architecture, circuit topology design, and systematic optimization of the different transceiver blocks is necessary. Moreover, optimization of the transceiver as one single block by minimizing the number of power-hungry interface circuits is emphasized. As examples, a fully integrated cellular transceiver front-end, a low-power extremely low noise-figure low-noise amplifier, and a very efficient power amplifier are demonstrated. Index Terms--CMOS, low power, low voltage, receiver, RF, transceiver, wireless.

Insertion loop 256-268 in coagulation factor IX is discussed. It restricts enzymatic activity where factor VIII is absent. a study has shown that the loop restricts the activity of factor IXa toward synthetic and natural substrates. Complex formation of factor VIIIa cuts back on the inhibitory effect of the insertion loop on activation of FX.

The interaction between plasminogen activator inhibitor 1 (PAI-1), thrombin and glycosaminoglycans was investigated. It was shown that only high molecular weight heparin, containing at least 14 monosaccharide units, acts as an efficient cofactor for thrombin inhibition by PAI-1. A dye displacement assay was used to measure difference spectra between haprin/proflavine vs proflavine. The displacement of the dye by thrombin, but not by PAI-1, indicated that high molecular weight heparin accomodates separate binding sites for thrombin and PAI-1.

Abstract Background The increasing incidence of hepatocellular carcinoma in Western countries has led to an expanding interest of scientific research in this field. Therefore, a vast need of experimental models that mimic the natural pathogenesis of hepatocellular carcinoma (HCC) in a short time period is present. The goal of our study was (1) to develop an efficient mouse model for HCC research, in which tumours develop in a natural background of fibrosis and (2) to assess the time-dependent angiogenic changes in the pathogenesis of HCC. Methods Weekly intraperitoneal injections with the hepatocarcinogenic compound N-nitrosodiethylamine was applied as induction method and samples were taken at several time points to assess the angiogenic changes during the progression of HCC. Results The N-nitrosodiethylamine-induced mouse model provides well vascularised orthotopic tumours after 25 weeks. It is a representative model for human HCC and can serve as an excellent platform for the development of new therapeutic targets.

The role of interface between the second epidermal growth factor (EGF2) domain and the protease domain of activated factor IX (FIXa) was studied with particular focus on the putative interdomain contacts in the FIXa structure and for this recombinant FIX variants with mutations at residue Asn92, Phe98, Tyr295 and Phe299 were analyzed. Results suggest that putative interdomain contacts involving residues Asn92, Phe98, Tyr295 and Phe299 affect reactivity toward activate factor (FX).

In perennial ryegrass breeding programmes, dry‐matter yield (DMY) of individual plots is monitored destructively at the different cuts or derived from non‐destructive canopy height measurements using devices like rising plate meters (RPM). These approaches both have constraints. Destructive sampling implies low temporal resolution, restraining the study of dry‐matter accumulation rates, while RPM measurements are influenced by the canopy structure and limit intra‐field variability identification. We present a phenotyping methodology, based on the use of an affordable RGB camera mounted on an unmanned aerial vehicle (UAV), to monitor the spatial and temporal evolution of canopy height and to estimate DMY. Weekly flights were carried out from April to October above a field comprising a diverse set of accessions. To test the capacity of UAV imagery to estimate canopy height, 8 ground control points and 28 artificial height references were placed at different locations. Accurate flights with an RMSE as low as 0.94 cm were achieved. In addition, canopy height was recorded using an RPM and destructive biomass samples were collected. Different models (linear, multiple linear, principal components, partial least squares regression and random forest) were used to predict DMY, and their performance was evaluated. The best estimations were obtained by combining variables including canopy height, vegetation indices and environmental data in a multiple linear regression (R2 = .81). All models built using UAV data obtained a lower RMSE than the one using RPM data. The approach presented is a possibility for breeders to incorporate new information in their selection process. [ABSTRACT FROM AUTHOR]

The D0-D3 fragment of von Willebrand factor (VWF) can be divided into TIL0-E0-VWD3-C8_3-TIL3-E3 subdomains of which TIL0-E0-VWD3 comprises the main factor VIII (FVIII)-binding region. Yet, von Willebrand disease (VWD) Type 2 Normandy (2N) mutations, associated with impaired FVIII interaction, have been identified in C8_3-TIL3-E3. We now assessed the role of the VWF (sub)domains for FVIII binding using isolated D0, D3 and monomeric C-terminal subdomain truncation variants of D0-D3. Competitive binding assays and surface plasmon resonance analysis revealed that D0 requires the presence of D3 for effective interaction with FVIII. The isolated D3 domain, however, did not show any FVIII binding. Results indicated that the E3 subdomain is dispensable for FVIII binding. Subsequent deletion of the other subdomains from D3 resulted in a progressive decrease in FVIII-binding affinity. Chemical footprinting mass spectrometry suggested increased conformational changes at the N-terminal side of D3 upon subsequent subdomain deletions at the C-terminal side of the D3. A D0-D3 variant with a VWD type 2N mutation in VWD3 (D879N) or C8_3 (C1060R) also revealed conformational changes in D3, which were proportional to a decrease in FVIII-binding affinity. A D0-D3 variant with a putative VWD type 2N mutation in the E3 subdomain (C1225G) showed, however, normal binding. This implies that the designation VWD type 2N is incorrect for this variant. Results together imply that a structurally intact D3 in D0-D3 is indispensable for effective interaction between D0 and FVIII explaining why specific mutations in D3 can impair FVIII binding. [ABSTRACT FROM AUTHOR]

Centrifugal fertilizer spreaders are by far the most commonly used granular fertilizer spreader type in Europe. Their spread pattern however is error-prone, potentially leading to an undesired distribution of particles in the field and losses out of the field, which is often caused by poor calibration of the spreader for the specific fertilizer used. Due to the large environmental impact of fertilizer use, it is important to optimize the spreading process and minimize these errors. Spreader calibrations can be performed by using collection trays to determine the (field) spread pattern, but this is very time-consuming and expensive for the farmer and hence not common practice. Therefore, we developed an innovative multi-camera system to predict the spread pattern in a fast and accurate way, independent of the spreader configuration. Using high-speed stereovision, ejection parameters of particles leaving the spreader vanes were determined relative to a coordinate system associated with the spreader. The landing positions and subsequent spread patterns were determined using a ballistic model incorporating the effect of tractor motion and wind. Experiments were conducted with a commercial spreader and showed a high repeatability. The results were transformed to one spatial dimension to enable comparison with transverse spread patterns determined in the field and showed similar results. [ABSTRACT FROM AUTHOR]

Better characterization of the fertilizer spreading process, especially the fertilizer pattern distribution on the ground, requires an accurate measurement of individual particle properties and dynamics. Both 2D and 3D high speed imaging techniques have been developed for this purpose. To maximize the accuracy of the predictions, a specific illumination level is required. This paper describes the development of a high irradiance LED system for high speed motion estimation of fertilizer particles. A spectral sensitivity factor was used to select the optimal LED in relation to the used camera from a range of commercially available high power LEDs. A multiple objective genetic algorithm was used to find the optimal configuration of LEDs resulting in the most homogeneous irradiance in the target area. Simulations were carried out for different lenses and number of LEDs. The chosen configuration resulted in an average irradiance level of 452 W/m2 with coefficient of variation less than 2%. The algorithm proved superior and more flexible to other approaches reported in the literature and can be used for various other applications. [ABSTRACT FROM AUTHOR]