These nuclear-encoded chloroplast

proteins are synthesised by cytoplasmatic ribosomes and transported post-translationally into the chloroplast. Some of them are assembled with the plastid-encoded PF-04929113 proteins to form functional complexes (e.g. Rubisco, ATP-synthase). For reliable measuring, the expression levels of photosynthetic genes, which can be nuclear- or plastid-encoded, selection of multiple appropriate reference genes for normalisation is very important. Gene expression levels have commonly been determined using northern blot analysis. However, this technique is time-consuming and requires a large quantity of RNA (Dean et al. 2002). The most widely used mRNA quantification methods nowadays are real-time fluorescence detection assays (Heid et al. 1996), due to their conceptual simplicity, sensitivity, practical ease and high-throughput capacity (Vandesompele et al. 2002; Bustin 2000). Mostly, normalisation of gene expression has been studied by using one selected MK-4827 “housekeeping gene” which is involved in basic cellular processes, and which is supposed to have a uniform level of expression across

different treatments, organs and developmental stages (Vandesompele et al. 2002). However, many studies have shown that the expression of these “housekeeping genes” can vary with the experimental conditions (Czechowski et al. 2005; Thellin et al. 1999; Gonçalves et al. 2005). Furthermore, as a new standard in real-time PCR, at least two or three housekeeping genes should be used as internal standards,

because the use of a single gene for normalisation can lead to large errors (Thellin et al. 1999; Vandesompele et al. 2002; Gutierrez et al. 2008). Studies on the identification of multiple reference genes mainly deal with human ever tissues, bacteria and viruses. Only a few publications exist for plants: for potato under biotic and abiotic stress (Nicot et al. 2005); for rice under hormone, salt and drought stress (Kim et al. 2003); for Arabidopsis selleck chemicals thaliana and tobacco under heat-stress and developmental changes (Volkov et al. 2003); for maritime pine during embryogenesis (Gonçalves et al. 2005) and for Arabidopsis thaliana under different environmental conditions and developmental stages (Czechowski et al. 2005; Remans et al. 2008). Reference genes for normalisation of plastid-encoded genes have not yet been determined. We selected from previous reports and micro-array data five nuclear-encoded and nine plastid-encoded reference genes and evaluated these in transgenic tobacco plants with increased (Pssu-ipt) and diminished cytokinin (35S:AtCKX1) content and their respective wild types, using the geNorm (Vandesompele et al. 2002) algorithm.

The oxygen for interface W oxidation should come from the La2O3 film. It was proposed that the oxygen in W may diffuse into the La2O3 film to fill up the oxygen vacancies there [14]. Oxygen vacancies are the major defect centers in La2O3 which result in several instability issues and enhance the gate leakage current [15–17]. The present result indicates that a reverse process may have been Selleck 3-deazaneplanocin A taken place in the present samples. That means a high-temperature process may

lead to the out-diffusion of oxygen to the W/La2O3 interface, and that increases oxygen vacancies in the La2O3 film. In addition, La-O-W bonding with a peak energy of 532.2 eV was found. For the case of WO x phase enhancement, it should not affect the EOT as it can be considered as part of the metal electrode; on the other hand, the effects of La-O-W bonding have never been explored, and it should have some impact in making the effective EOT thicker. Figure 1 W 4f XPS spectra with Gaussian

decomposition. This figure shows various oxidized states of tungsten near the W/La2O3 interface. (a) As-deposited film. (b) Sample with thermal annealing at 600°C for 30 min. check details A stronger WO x peak was observed. Figure 2 O 1s spectra taken near the W/La 2 O 3 interface. (a) Three oxidation states, corresponding to WO3, WO x , and La-O, were found for the as-deposited film. (b) After thermal annealing, an additional peak, attributing to La-O-W bonding, was found at an energy of 532.2 eV. Silicon/high-kinterface High-k can react, especially in the presence of a silicon oxide layer, with the silicon substrate, Phosphoprotein phosphatase and the electronic bonding structure at the La2O3/Si interface should be much more complicated than the SiO2/Si case. It was known that the interface bonding may lead to either an insulating layer (silicate bonding) or JNJ-26481585 conductive layer (silicide bonding) [1, 2]. Most of the high-k

silicides are conductive. The interfacial silicide layer will not affect the EOT but the interface metal-Si bonding in the interface trap precursors and results in the channel mobility degradation and other instabilities [1, 15, 16]. Most of the high-k materials including hafnium oxide and lanthanum oxide are only marginally stable against the formation of silicates. The device properties can be improved with the interfacial silicate layer [1]. However, this layer has much smaller k values and becomes the lower bound of the thinnest EOT, and needs to be minimized for the subnanometer EOT dielectric. Figure  3 shows the La 3d XPS spectra at different depths. The different depths were obtained by argon sputtering for 2.5 to 8 min, and all the XPS analyses were made at a take-off angle of 45°. This treatment should be able to minimize the artifacts due to ion knock-on effects. The bulk La 3d3/2 XPS spectra shows a main peak energy of 851.9 eV and a satellite peak energy of 855.6 eV [1]. As sputtered closer to the substrate, the main peak of La 3d3/2 shifts to an even higher energy side of 852.