5.?Diagnosis of Cancer by SPRThe activation of epidermal growth factor (EGF) receptor (EGFR) on epidermal cells, such as keratinocytes, causes a unique triphasic change of RA, whereas the activation of other receptors, such as the high affinity IgE receptor (Fc��RI) on mast cells and basophils, causes a monophasic increase of RA. Chinese hamster ovary (CHO) cells transfected with cDNA for EGFR also showed a triphasic change of RA. However, when CHO cells were transfected with cDNA for EGFR containing a mutation at its kinase domain, they showed a minimal change of RA. Moreover, a phosphatidylinositol 3-kinase inhibitor attenuated the third phase of RA change in CHO cells expressing wild-type EGFR. Furthermore, the pattern of RA change was independent of EGF concentration.

These results suggest that EGF induces the SPR signals via the phosphorylation of EGFR, and that an impaired pattern of SPR signal induced by EGF may reveal a disorder in intracellular signal transductions of abnormal cells, such as cancer cells. In fact, we found that five out of six carcinoma cell lines showed mono- or bi-phasic change of RA (Figure 3). These results suggest the potential for the SPR biosensor tobe applied to the real-time detection and/or diagnosis of malignant tumors [16].Figure 3.SPR signals (change of angle of resonance (AR)) in six cell lines established from different cancers. TMK-1 cells showed weak, but complete, triphasic changes of AR, whereas the other five cell lines showed unique incomplete patterns of SPR signals. Adapted …6.

?Optic Fiber SPRThe application of an optical fiber sensors-based SPR phenomenon has been reported for the analysis of liquid or gas samples [47,48]. To apply SPR biosensors for the inside of the body, we developed an optic fiber SPR for living cells analysis. The core of 200 ��m diameter with 1cm length of an optical fiber was coated by gold film with 50 nm thickness. The light provided by a white LED and attenuated due to an SPR phenomenon in the sensor part was analyzed using a spectrum detector. RIchanges on a gold surface were indicated by shifts of the wavelength of the maximal absorption (Figure 4). Using this sensor, the difference in solvents with various RI and protein bindings to the sensor chip was detected with sufficient Batimastat sensitivity. Moreover, when RBL-2H3 mast cells were fixed onto the sensor tip surface by means of the droplet method, it detected a sustained increase of RI in response to antigen [32].Figure 4.Construction and sensitivity of the optic fiber SPR sensor. (a) The optic fiber SPR sensor was composed of a light source (white LED), a plastic cladding multimode optical fiber with quartz core (200/230), fiber connecter (SC), a fiber coupler, a spectrometer, …7.

Compared with the other glasses, Er3+ doped silicate glass possesses higher chemical durability and thermal stability and it could be more easily fabricated into different products for use, such as Er3+ doped fiber optical sensor for temperature measurement because of perfect match of the compositions between fiber and our silicate sample. Moreover, extensive research of the photoluminescence (PL) properties of Er3+ doped silicate glass proved that silicate glass is more appropriate as the Er3+ doped matrix for it possesses improved fluorescence efficiency and decay time [13,14].In this paper, we present experimental results of green up-conversion emissions of Er3+ doped silicate glass in the temperature range of 296K-673K, in order to explore a developing possibility of optical high temperature sensor based on the FIR technique from the green up-conversion emissions.

2.?ExperimentalThe 100.000g powders with corresponding compositions of 9.41Er2O3-66.35SiO2- 10.75B2O3-3.07BaO-10.42Na2CO3 (g) were homogenized and compacted in 50ml corundum crucible, then heated at 1723K for 30min in the high-temperature furnace. When the glass stock of Er3+ doped took on molten state, it was poured into moulds and then moved into another furnace at 873K. After 10min, the samples were taken out of the moulds, put on asbestos web and maintained for 3h, then cooled down to room temperature naturally in the furnace. The 0.8at% Er3+ doped silicate glass samples were incised with dimension of 10mm��10mm��3mm and polished.The sample was placed in a furnace and its temperature from 296K to 673K with measurement error of ��1.

5K was monitored with a copper-constantan thermocouple set to its back-face. The green up-conversion emissions spectra in the wavelength range of 500nm- 600nm were detected from the sample using a 978nm semiconductor laser diode (LD) as an excitation source with excitation power of 0.8W, corresponding to a power density of 4.0��102 W cm-2. The green up-conversion emissions were focused onto a single-monochromator, and detected with a CR131 photomultiplier tube associated with a lock-in Drug_discovery amplifier. The spectral resolution of the experimental set-up was 0.1nm.3.?Results and DiscussionFigure 1 shows a simplified energy level diagram of the green up-conversion emissions for the Er3+ doped silicate glass by a 978 nm LD excitation [15,16]. The excited state absorption (ESA) of 4I11/2+a photon��4F7/2 and cross-relaxation (CR) of 4I11/2+4I11/2��4I15/2+4F7/2 populate the Er3+ on 4F7/2 level by following the ground state absorption (GSA) of 4I15/2+a photon��4I11/2, and a nonradiative decay from 4F7/2 to 2H11/2 and 4S3/2 levels produce the final green up-conversion emissions population of Er3+.

Such relationship is easy to apply, however, only valid for a single study site, under the condition that surface roughness remains constant over successive radar acquisitions [e.g., 17, 18]. The mostly used semi-empirical models, developed by Oh et al. [19] and Dubois et al. [20, 21], are based on a theoretical foundation, however, they still contain model parameters that are derived from experimental data. Conversely, theoretical models present an approximate physical description of wave scattering on rough surfaces. Amongst the mostly used physical approximations are the Small Perturbation Model (SPM) [22], the Kirchhoff Approximations [23] and the IEM [15, 16]. Despite their theoretical foundation, many of these models cannot be applied operationally because of their narrow validity ranges for the majority of natural surfaces.

The model with the largest validity range concerning roughness parameters is probably the IEM. Because of this, the IEM has become the most widely used scattering model for bare soil surfaces [24], which gives a sound justification for use in the present theoretical study.The single scattering approximation of the IEM calculates backscatter coefficients ��VV0 and ��HH0, given the dielectric constant �� of a bare soil, the radar frequency f (GHz), the incidence angle �� (��) and roughness parameters: s (cm), l (cm) and an ACF. Since many authors [e.g., 7, 8, 11, 25] found that for agricultural soils the ACF is well approximated by an exponential function, this type of ACF will be adopted in all further simulations.

Based on several experiments, the validity condition of the single scattering approximation of the IEM is often expressed by ks < 3 [e.g., 16], with k the wave number equal to 2��/�� and �� the wavelength. In many problems, soil moisture (dielectric constant) needs to be modelled based on observed backscatter coefficients, i.e. the IEM should be applied inversely. Several inversion algorithms have been developed, including Look-Up Tables (LUT) [e.g., 26], neural networks [e.g., 27], and the method of least squares [e.g., 28, 29]. Alternatively, the inversion problem can be solved iteratively [e.g., 30], which is preferred in this theoretical study because of its simplicity. To translate the dielectric constant into soil moisture, the four-component dielectric mixing model of Dobson et al. [2] is used.

Table 1 lists the input parameters for the IEM and the dielectric mixing model used in the remainder of this work. As was also applied by Verhoest et al. [31, 32], retrieved moisture contents above 45 vol% are set equal to 45 vol%, whereas moisture contents below 2 vol% are set to 2 vol%, in order to limit the retrieval results to plausible soil moisture contents o
A biosensor Batimastat is a device incorporating a biological sensing element either intimately connected to or integrated within a transducer.