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Early detection and treatment are important for the successful eradication of various cancers; therefore, the development of economical, noninvasive novel cancer screening systems is critical. Previous reports using canine scent detection have demonstrated the existence of cancer-specific odors. However, it is difficult to introduce canine scent recognition into clinical practice because of the need to maintain accuracy. In this study, we developed a Nematode-Nose (N-NOSE) test using Caenorhabditis elegans to provide a novel, highly accurate cancer detection system that is economical, painless, rapid, and convenient. We demonstrated that wild-type C. elegans displayed attractive chemotaxis toward human cancer cell secretions, cancer tissues, and urine from cancer patients but avoided control urine. In parallel, C. elegans olfactory neurons showed a significantly stronger response to urine from cancer patients than to control urine. In contrast, G protein α mutants and animals with ablated olfactory neurons were not attracted to urine from cancer patients, suggesting that they sense odors in urine. We tested 242 samples to measure the performance of the N-NOSE test and found that the sensitivity was 95.8%, which is markedly higher than that of other existing tumor markers. Furthermore, the specificity was 95.0%. Importantly, this test could detect various cancer types tested at the early stage (stage 0 or 1). C. elegans scent-based analyses therefore might provide a new strategy for the detection and study of disease-associated scents.

We examine electronic and crystal structures of iron-based superconductors

Cell morphology is recognized as an important hallmark of neural cells. During the differentiation of human pluripotent stem cells (hPSCs) into neural cells, cell morphology changes dynamically. Therefore, characterization of the morphology of cells during this period is important to improve our understanding of the differentiation and development of neural cells. General methods for the directed induction of hPSCs include the steps of multi-cellular aggregation or high-density cell culture, particularly at the early phase of neural differentiation, and therefore, the morphology of each differentiating cell is difficult to recognize. Here, we have developed a new method for the directed differentiation of neuroepithelial-like cells (NELCs) from hPSCs at a low cell density in an adherent monolayer culture, as well as an image-processing algorithm to evaluate the cell morphology of differentiating NELCs, in order to follow cell morphology during the differentiation of hPSCs into NELCs. Using these methods, the morphological transition of differentiating cells was observed in real time using phase contrast imaging and then quantified. Because cell morphology is also considered an inherent biological marker of neural cells cultured in vitro, this method is potentially useful to study the mechanisms underlying neural cell differentiation.

We have investigated bulk-derived electronic structure of the valence transition system Eu(Rh 1– x Co x ) 2 Si 2 with x = 0 and 0.4 by means of hard x-ray photoemission spectroscopy. The Eu mean valence evaluated from the Eu 3 d spectrum for x = 0.4 gradually changes from 2.57 at 300 K to 2.92 at 20 K. On the other hand, the valence for x = 0 retains ∼2.1 in the temperature range from 300 to 20 K. Furthermore, the Eu 2+ 4 f component in the valence band for x = 0.4 was shifted by 150 meV towards the Fermi level compared to that for x = 0. Present results suggest that the increase in the hybridization strength between Eu 4 f and conduction electrons induces the valence transition, which is consistent with the Kondo volume collapse model.

From the recent advances, there are growing expectations toward the mass production of induced pluripotent stem cells (iPSCs) for varieties of applications. For such type of industrial cell manufacturing, the technology which can stabilize the production efficiency is strongly required. Since the present iPSC culture is covered by delicate manual operations, there are still quality differences in produced cells from same culture protocols. To monitor the culture process of iPSCs with the quantified data to evaluate the culture status, we here introduce image-based visualization method of morphological diversity of iPSC colonies. We have set three types of experiments to evaluate the influential factors in iPSC culture technique that may disturb the undifferentiation status of iPSC colonies: (Exp. 1) technical differences in passage skills, (Exp. 2) technical differences in feeder cell preparation, and (Exp. 3) technical differences in maintenance skills (medium exchange frequency with the combination of manual removal of morphologically irregular colonies). By measuring the all existing colonies from real-time microscopic images, the heterogenous change of colony morphologies in the culture vessel was visualized. By such visualization with morphologically categorized Manhattan chart, the difference between technical skills could be compared for evaluating appropriate cell processing.

Background/aim Early detection of gastrointestinal cancer may reduce mortality. Recently, Caenorhabditis elegans has been reported to be capable of differentiating patients with cancers from healthy persons by the smell of urine. This novel technique using C. elegans olfaction has been named as Nematode-NOSE (N-NOSE). Materials and methods We collected 180 urine samples from patients with gastrointestinal cancer and 76 samples from healthy subjects. N-NOSE test was performed using these samples and N-NOSE index was obtained. Quantification of the olfactory behavior of C. elegans was performed as established in past studies. By receiver operating characteristic (ROC) analysis, we examined the diagnostic capability of N-NOSE. Results ROC analysis revealed that N-NOSE showed an area under the curve value of more than 0.80, even in early-stage cancers. Conclusion C. elegans olfaction enabled the detection of gastrointestinal cancers from urine with high sensitivity, which can provide the basis for the development of N-NOSE as a gastrointestinal cancer screening test.

The photoinduced valence dynamics of ${\mathrm{EuNi}}_{2}{({\mathrm{Si}}_{0.21}{\mathrm{Ge}}_{0.79})}_{2}$ were investigated using time-resolved x-ray absorption spectroscopy for Eu ${M}_{5}$ edge. Through the pump-probe technique with synchrotron x-ray and Ti:sapphire laser pulses, a photoinduced valence transition was observed from ${\mathrm{Eu}}^{3+}$ to ${\mathrm{Eu}}^{2+}$. Because the lifetime of a photoinduced state can be up to 3 ns, a metastable state is considered to be realized. By comparing the experimental results with the theoretical calculations, the photoinduced valence transition between Eu $4f$ and conduction electrons was quantitatively evaluated.

We examine electronic and crystal structures of iron-based superconductors LnFeAsO1−x H x (Ln = La, Sm) under pressure by means of x-ray absorption spectroscopy (XAS), x-ray emission spectroscopy (XES), and x-ray diffraction. In LaFeAsO the pre-edge peak on high-resolution XAS at the Fe-K absorption edge gains in intensity on the application of pressure up to 5.7 GPa and it saturates in the higher pressure region. We found integrated-absolute difference values on XES for Ln = La, corresponding to a spin state, decline on the application of pressure, and then it is minimized when the T c approaches the maximum at around 5 GPa. In contrast, such the optimum value was not detected for Ln = Sm. We reveal that the superconductivity is closely related to the lower spin state for Ln = La unlike Sm case. We observed that As height from the Fe basal plane and As–Fe–As angle on the FeAs4 tetrahedron for Ln = La deviate from the optimum values of the regular tetrahedron in superconducting (SC) phase, which has been widely accepted structural guide to SC thus far. In contrast, the structural parameters were held near the optimum values up to ∼15 GPa for Ln = Sm.

X-ray photoemission spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) are powerful techniques for revealing Hamiltonian parameters in strongly correlated electron systems. XPS and XAS spec...

Electronic structures of the temperature-induced valence transition system EuNi2(Si1–xGex)2 with x = 0.70, 0.79, 0.82 have been investigated by means of high-energy resolution fluorescence detection X-ray absorption spectroscopy (HERFD-XAS). The HERFD-XAS spectra clearly change their intensities of Eu2+ and Eu3+ components which directly reflect the temperature-induced valence transition. For x = 0.70, gradual spectral change exhibits a continuous valence transition, while drastic changes for x = 0.79 and 0.82 indicate first-order valence transitions. High-energy resolution measurements made it possible to observe additional fine structures which are recognized more clearly below the transition temperature. Existence of these fine structures suggests that many-body effect plays an important role in the temperature-induced valence transition of this system. The variation of Eu mean valence estimated from the HERFD-XAS spectra for each x correlates with that of magnetic susceptibility.

We present a computational study of $L$-edge resonant inelastic x-ray scattering (RIXS) in correlated 3$d$ transition-metal oxides using an $ab$ $initio$ method based on local density approximation + dynamical mean-field theory (DMFT). The present method, building on Anderson impurity model with an optimized continuum bath within DMFT, is an extension of the cluster model to include unbound electron-hole pair excitations as well as material-specific charge-transfer excitations with less empirical parameters. We find a good agreement with available experimental data. The relationship between correlated bands and fluorescence-like feature in the RIXS spectra is discussed.

While the charge transfer between the transition metal and oxygen sites in transition metal oxides has been studied by resonant inelastic soft X-ray scattering, the charge transfer between transition metal sites has not been studied as of yet. In this study, we have measured the Ti 2p edge resonant inelastic X-ray scattering spectra of MTiO3 (M = Mn, Fe, Co, and Ni) in order to investigate the intermetallic M 3d–Ti 3d charge transfer. We found the peak around −4.5 eV in the energy loss scale for all MTiO3, which is attributed to the M 3d–Ti 3d charge transfer; whereas only FeTiO3 exhibits an additional intermetallic charge transfer peak at −2.5 eV. We attributed that the existence of the additional peak in FeTiO3 reflects the relation of M 3d and Ti 3d energy levels.

The Ras-MAP kinase signaling pathway plays important roles for the olfactory reception in olfactory neurons in Caenorhabditis elegans. However, given the absence of phosphorylation targets of MAPK in the olfactory neurons, the mechanism by which this pathway regulates olfactory function is unknown. Here, we used proteomic screening to identify the mitochondrial voltage-dependent anion channel VDAC-1 as a candidate target molecule of MAPK in the olfactory system of C. elegans. We found that Amphid Wing "C" (AWC) olfactory neuron-specific knockdown of vdac-1 caused severe defects in chemotaxis toward AWC-sensed odorants. We generated a new vdac-1 mutant using the CRISPR-Cas9 system, with this mutant also showing decreased chemotaxis toward odorants. This defect was rescued by AWC-specific expression of vdac-1, indicating that functions of VDAC-1 in AWC neurons are essential for normal olfactory reception in C. elegans. We observed that AWC-specific RNAi of vdac-1 reduced AWC calcium responses to odorant stimuli and caused a decrease in the quantity of mitochondria in the sensory cilia. Behavioral abnormalities in vdac-1 knockdown animals might therefore be due to reduction of AWC response, which might be caused by loss of mitochondria in the cilia. Here, we showed that the function of VDAC-1 is regulated by phosphorylation and identified Thr175 as the potential phosphorylation site of MAP kinase.

We investigated the electronic structure of BaFeO3 by using HAXPES and XAS measurements and first principle studies. The experimental and theoretical results indicated that BaFeO3 is a negative charge transfer compound. We concluded that the on-site Coulomb energy and the strong hybridization between Fe-3d and O-2p orbitals play a very important role of emergence of negative charge transfer. And we found the new structure in the Fe-2p XPS spectrum and concluded this structure is originated from non-local screening. (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

We present a computational study of 2$p$ core-level X-ray photoemission spectra of transition metal monoxides MO (M=Ni, Co, Mn) and sesquioxides M$_2$O$_3$ (M=V, Cr, Fe) using a theoretical framework based on the local-density approximation (LDA) $+$ dynamical mean-field theory (DMFT). We find a very good description of the fine spectral features, which improves considerably over the conventional cluster model. We analyze the role of the non-local screening and its relationship to the long-range magnetic order and the lattice geometry. Our results reveal the potential of the present method for the analysis and interpretation of the modern high-energy-resolution experiments., Comment: 9 pages, 8 figures

We investigated the bulk-derived electronic structure of the temperature-induced valence transition system ${\mathrm{EuNi}}_{2}$(${\mathrm{Si}}_{1\ensuremath{-}x}{\mathrm{Ge}}_{x}$)${}_{2}$ ($x=0.70$, 0.79, and 0.82) by means of hard x-ray photoemission spectroscopy (HAXPES). The HAXPES spectra clearly show distinct temperature dependencies in the spectral intensities of the ${\mathrm{Eu}}^{2+}$ and ${\mathrm{Eu}}^{3+}\phantom{\rule{4pt}{0ex}}3d$ components. For $x=0.70$, the changes in the ${\mathrm{Eu}}^{2+}$ and ${\mathrm{Eu}}^{3+}\phantom{\rule{4pt}{0ex}}3d$ spectral components with temperature reflect a continuous valence transition, whereas the sudden changes for $x=0.79$ and 0.82 reflect first-order valence transitions. The Eu $3d$ spectral shapes for all $x$ and particularly the drastic changes in the ${\mathrm{Eu}}^{3+}\phantom{\rule{4pt}{0ex}}3d$ feature with temperature are validated by a theoretical calculation based on the single-impurity Anderson model (SIAM). SIAM analysis reveals that the valence transition for each $x$ is controlled by the $c\ensuremath{-}f$ hybridization strength and the charge-transfer energy. Furthermore, the $c\ensuremath{-}f$ hybridization strength governs the valence transition of this system, which is either first order or continuous, consistent with Kondo volume collapse.

The charge ordering of Fe 2+ and Fe 3+ ions in LuFe 2 O 4 induces ferroelectricity below 330 K. In this study, the X-ray absorption spectra (XAS) at the Fe L 2,3 -edge are investigated to study charge ordered- and disordered-states. The polarization dependence of XAS revealed that the energy level of ( d xy , d x 2– y 2 ) is lower than that of ( d yz , d zx ). In the charge-ordered state, the Fe L 3 -XAS shows a double-peak structure, which is a characteristic of Fe 2+ and Fe 3+ ions. In the high-temperature region, the double-peak structure becomes a broad single peak, because of overlap with the thermally excited state.

Perovskite PbCoO

The technique used for cancer monitoring is essential for effective cancer therapy. Currently, several methods such as diagnostic imaging and biochemical markers have been used for cancer monitoring, but these are invasive and show low sensitivity. A previous study reported that Caenorhabditis elegans sensitively discriminated patients with cancer from healthy subjects, based on the smell of a urine sample. However, whether C. elegans olfaction can detect the removal of cancerous tumours remains unknown. This study was conducted to examine C. elegans olfactory behaviour to urine samples collected from 78 patients before and after surgery. The diagnostic ability of the technique termed Nematode-NOSE (N-NOSE) was evaluated by receiver operating characteristic (ROC) analysis. The ROC curve of N-NOSE was higher than those of classic tumour markers. Furthermore, we examined the change in C. elegans olfactory behaviour following exposure to preoperative and postoperative samples. The results suggest that a reduction in attraction indicates the removal of the cancerous tumour. This study may lead to the development of a noninvasive and highly sensitive tool for evaluating postoperative cancer patients.

Visual Abstract, Human neurons expressing mutations associated with neurodegenerative disease are becoming more widely available. Hence, developing assays capable of accurately detecting changes that occur early in the disease process and identifying therapeutics able to slow these changes should become ever more important. Using automated live-cell imaging, we studied human motor neurons in the process of dying following neurotrophic factor withdrawal. We tracked different neuronal features, including cell body size, neurite length, and number of nodes. In particular, measuring the number of nodes in individual neurons proved to be an accurate predictor of relative health. Importantly, intermediate phenotypes were defined and could be used to distinguish between agents that could fully restore neurons and neurites and those only capable of maintaining neuronal cell bodies. Application of live-cell imaging to disease modeling has the potential to uncover new classes of therapeutic molecules that intervene early in disease progression.

Resonant inelastic X-ray scattering (RIXS) spectra for Ni 2 p to 3 d excitation and 3 d to 2 p de-excitation of NiO are studied both theoretically and experimentally. Theoretical calculations with a single impurity Anderson model (SIAM) describe the charge transfer (CT) and d – d excitations in RIXS, and detailed study is made for the CT energy. High resolution RIXS measurements reveal the precise d – d excitation structure and its polarization dependence, and they are well reproduced by the SIAM calculation.

We have investigated the effect of interface states on the performance of a field-effect transistor composed of a SrTiO 3 (100) single crystal as a channel and an amorphous CaHfO 3 layer as a gate insulator. The amorphous CaHfO 3 gate insulator layer, which was grown at a pressure above 1 mTorr by pulsed laser deposition (PLD), had a breakdown field of over 5 MV/cm. The transistors deposited under “hard” ablation conditions, at a laser fluence of ∼1.2 J/cm 2 , showed a normally on conducting behavior even at zero gate bias. An annealing treatment was found to decrease the interface conductivity by filling oxygen vacancies and the annealed devices exhibited clear enhancement-type transistor action.

We analyze Ni 2 p →3 d →2 p resonant X-ray emission spectroscopy (RXES) of NiO with the impurity Anderson model. We pay attention to the inelastic X-ray scattering structures arising from the interatomic charge transfer (CT) from ligand state to 3 d state. We take into account a finite width of the O 2 p valence band in order to reproduce the experimental CT excitations in RXES, where two different CT structures are observed depending on the incident photon energy set in the CT satellite region of X-ray absorption spectra. The origin of these two CT excitation peaks is ascribed to the lower and upper edges of the 3 d 9 L nonbonding band in the final state of RXES. The value of CT energy Δ is estimated from our calculation. By analyzing XAS and RXES simultaneously with changing Δ from 2.0 eV to 6.5 eV by the step of 0.5 eV, we conclude that the most appropriate value of Δ is 3.5 eV. Also, in our calculation two different geometrical configurations are considered, which are called polarized and depolarized ...

K-edge X-ray absorption and 2p-XPS spectra of 3d-element oxides present spectral features which cannot be explained within a simple one-electron model. These features reveal the fine electronic structure of transition metal (TM) oxides valence states resulting from hybridized TM-3d and O-2p states, and the correlations between these valence electrons. In this paper, we show how resonant electronic spectroscopy (resonant Auger or resonant photoelectron spectroscopy) around the TM K-edge can be used to interpret the structures of the threshold and, with the help of theoretical calculation, to determine the electronic configuration of the excited ion. Quadrupolar transitions towards localized 3d orbitals are hence detected and quantitatively characterized in the titanium K-edge prepeaks in TiO2 and in the Ni K-edge prepeaks in NiO by angular-dependent resonant KLL Auger measurements. Valuable information also seems to be available in the resonant behavior of 2p-XPS spectra of NiO and Fe2O3.

Ti-K pre-peaks and Ti KL 23 L 23 resonant Auger spectra are theoretically investigated by means of a combined model between a TiO 6 charge-transfer cluster with full-multiplet interactions and an LCAO density-of-state calculation for a Ti 445 O 890 cluster. The results for Ti-K pre-peaks excellently reproduce both the spectral shape and incident-photon polarization dependence observed in the experiment by Danger et al. The present work corresponds to an improved calculation as compared to our previous study. The results for Ti KL 23 L 23 resonant Auger spectra also reproduce the features observed by Danger et al., especially the incident-photon energy and polarization dependence of the energy positions and the intensities of the Auger peaks. These facts mean that the mechanism for Ti-K pre-peaks, which we proposed earlier, is also applicable to the KL 23 L 23 resonant Auger processes.

Theoretical calculations of the Sc 2p → 3d → 2p resonant X-ray emission spectroscopy (RXES) in ScF3, ScCl3 and ScBr3 are performed with a ScX6 (X = F, Cl and Br) cluster model. Effects of incident photon polarization, intra-atomic multiplet coupling and interatomic hybridization are taken into account. We pay attention to the intensity ratio of the RXES spectra arising from nonbonding states, which has mainly two peaks due to the crystal field splitting. From the change of the spectral intensity in RXES we can find that the highest energy structure of the main peaks in X-ray absorption spectroscopy (XAS) varies from almost pure eg state to the eg and t2g mixed state according to the strength of multiplet effect and hybridization effect. © 2004 Elsevier B.V. All rights reserved.

A formalism is proposed to investigate quantum dynamics of localized states involving highly non-adiabatic time-evolution of electron–lattice systems. The effect of electron itinerancy is projected onto the dynamics of local variables through an integral kernel of Volterra's integral equation. The method is applied to the problem of thermal emission of carriers at deep level centers in semiconductors. It is shown that the real situation is in the adiabatic limit, and the probability of thermal emission of the trapped carriers is one per a single lattice oscillation, if the amplitude of the oscillation exceeds a critical value but zero if not.

Resonant electronic spectroscopy consists in measuring a non-radiative decay process (Auger or autoionization process) excited with photon energies around an absorption edge. The resonant spectra carry information both on the nature of the electronic transitions near the absorption edge by scanning the very first empty orbitals above the Fermi level (through the absorption process), and, on the other hand, on the atomic electronic configuration through the lineshape of the observed decay process. In this paper, after a quick review of the pioneering works in this field, we show that resonant measurements and their theoretical modeling can be used to precisely interpret complex absorption spectra. Hence, Ce resonant 3d photoemission spectra allow, in the Ce-L3 edge, to attribute the two white lines to 4f1 and 4f0 final state electronic configurations and to evidence the presence of a hidden 4f2 structure in the rise of the absorption threshold. Quadrupolar transitions towards localized 3d orbitals are also detected and quantitatively characterized in the titanium K-edge prepeaks in TiO2, thanks to angular dependent resonant Ti-KLL Auger measurements.

Various effects which cause the spin polarization in L 3 M 23 M 23 and L 3 M 1 M 45 Auger spectra of 3d transition metal systems are systematically studied by means of an atomic-model calculation including the full-multiplet coupling effect. We consider the following effects: (i) incident-photon polarization, (ii) 3d-core interactions in the intermediate and final states, (iii) resonance effect and (iv) configuration interaction between the L 3 M 23 M 23 and L 3 M 1 M 45 Auger final states. The model calculations are also compared with experimental data for ferromagnetic Fe metal films and it is shown that the agreement is fair. We also investigate theoretically the antiferromagnetically ordered system and show that the spin polarization is possible even for the antiferromagnetic case if the circularly polarized light is used.

Theoretical calculations of the Sc 2 p →3 d →2 p resonant X-ray emission spectroscopy (RXES) in ScF 3 , ScCl 3 and ScBr 3 are performed with a ScX 6 (X = F, Cl and Br) cluster model. Effects of int...

Resonant soft X-ray emission (RSXE) spectra of NaV2O5, MoxV1-xO2 and V2O3 have been recorded for a series of excitation energies at resonances of the V L- and O K-absorption band. Resonant excitation allows us, firstly, to separate V 3d and O 2p projected density-of-states of the valence band and, secondly, to study charge-neutral low-energy excitations due to resonant inelastic X-ray scattering (RIXS). We found that both the V L- and the O K-emission spectra clearly show components originating from O 2p- and V 3d-states, reflecting the high degree of hybridization of the valence band in all compounds. At threshold excitation we observed that NaV2O5 spectra are dominated by RIXS whereas MoxV1-xO2 and V2O3 spectra show bandlike features, which may be due to differences in the correlation effects of the compounds. We compared the RSXE spectra with cluster model calculations, which gives a good account for NaV2O5 whereas the RSXE spectra of the other compounds show RIXS only at certain energies well above the threshold. In fact, we interpret the trend in the RSXE spectra of the MoxV1-xO2 compound system as a successive filling of the (rigid) V 3d band with increasing Mo content. (C) 2003 Elsevier B.V. All rights reserved. (Less)

Co 3d → 2p X-ray emission spectra of LaCoO 3 in the Co 2p photoabsorption region are measured at 40 and 300 K. The spectra mainly reveal features nearly independent of excitation photon energy. This indicates the highly covalent or strongly hybridized nature of the Co 3d state. The emission component showing resonant behavior is also observed. The temperature dependence of the resonant emission confirms that the wave function of Co 3d electrons is totally symmetric in the low-spin ground state and that for the spin state excited thermally through the magnetic transition around 100 K is not.

Detailed resonant X-ray emission spectra (XES) and these polarization dependences of Ti2O3 were obtained by excitation at the Ti 2p absorption edge. About 100 XES spectra were observed in different polarization configurations. X-ray Raman scattering spectra showed two types of crystal field (dd) excitations as well as charge-transfer (CT) excitations. Bulk states of the powder sample were obtained by the XES measurement, which is the photon-in/photon-out method. Partial photon yields (PPYs) of some elementary excitations were extracted from the XES spectra. The CT excitations were hidden in total electron yield spectra, but these were revealed by PPY measurements. Symmetry information of these excitations was acquired on the basis of polarization dependences.

The polarization dependence of 2 p →3 d →2 p resonant X-ray emission spectroscopy (RXES) in 3 d 1 , 3 d 2 and 3 d 3 systems (TiF 3 , VF 3 and Cr 2 O 3 , respectively) is measured and analyzed by means of the MX 6 (M denotes a transition metal and X denotes a ligand, respectively) cluster model. The results are compared with a previous one for the 3 d 0 system (TiO 2 ). Generally, with increasing 3 d electron number, the spectral structure of RXES becomes more complicated by the influence of the crystal field and the multiplet coupling effect. Moreover, we point out that the selection rules on the polarization dependence of RXES change with the 3 d electron number and that a drastic resonance enhancement corresponding to the excitation to an antibonding state in the 3 d 0 system is almost absent for the 3 d n systems with n = 1, 2 and 3.

The spectral change in the 3d resonant X-ray inelastic scattering (RIXS) induced by the spin-state transition between Kondo singlet (KS) and localized spin (LS) state is theoretically investigated for γ-like Ce intermetallics by means of a single impurity Anderson model. The basis configurations with an electron–hole pair are included in the calculation within the configuration interaction scheme, in addition to the intra-atomic full multiplet coupling of the Ce impurity. A distinct spectral change is found across the KS–LS transition in the RIXS excited at the charge-transfer satellite of the 3d X-ray absorption spectrum (XAS) under a polarized geometry. In contrast, the 3d XAS and RIXS spectra under a depolarized geometry are rather insensitive to the spin-state transition.

Partial fluorescence yield (PFY) spectroscopy, which corresponds to a high-resolution version of the X-ray absorption spectroscopy (XAS), is experimentally performed at the Ce L3 edge of CeO2, and the result is theoretically analyzed using an impurity Anderson model (IAM). In order to estimate the Ce 4f–5d interaction Ufd, we employ a semi-empirical IAM framework based on the local density approximation+U method; Slater–Koster parameters describing the valence of CeO2 are estimated by band mapping within the linear combination of atomic orbitals scheme, and the resulting realistic valence structure is considered in the IAM analysis. The global structure of the PFY-XAS result, which consists of the Ce 2p3/2 → 5d dipole transition and the Ce 2p3/2 → 4f quadrupole transition, is excellently reproduced by the calculation. The Ufd value is estimated to be 3.0 eV. We emphasize that the sensitivity of PFY-XAS to Ufd makes it a good ruler for obtaining the Ufd values of Ce compounds.

Polycrystalline CaCu3Rh4O12 is prepared from a stoichiometric mixture of CaO, CuO, Rh2O3, and KClO4 under high-pressure and high-temperature conditions (Pt capsule, 1273 K, 15 GPa, 30 min).

A novel perovskite oxide, CaCu3Rh4O12, has been synthesized under high-pressure and high-temperature conditions (15 GPa and 1273 K). Rietveld refinement of synchrotron X-ray powder diffraction data indicates that this compound crystallizes in a cubic AA'3B4O12-type perovskite structure. Synchrotron X-ray absorption and photoemission spectroscopy measurements reveal that the Cu and Rh valences are nearly trivalent. The spectroscopic analysis based on calculations suggests that the appropriate ionic model of this compound is Ca(2+)Cu(∼2.8+)3Rh(∼3.4+)4O12, as opposed to the conventional Ca(2+)Cu(2+)3Rh(4+)4O12. The uncommon valence state of this compound is attributed to the relative energy levels of the Cu 3d and Rh 4d orbitals, in which the large crystal-field splitting energy of the Rh 4d orbitals is substantial.

Core-level photoemission spectra of NiO and cuprates are theoretically investigated by means of an impurity Anderson model optimized within a dynamical mean-field theory considering realistic crystal structures. A characteristic double-peak structure of the Ni 2p3/2 main line is excellently reproduced by the calculation, where both antiferromagnetic ordering and final-state nonlocal screening accompanied by a Zhang-Rice doublet bound state play crucial roles in the formation of the double peaks. The analysis suggests the first ionization state of NiO to be the Zhang-Rice doublet bound state. A rich variety found in Cu 2p3/2 main-line shape of undoped and carrier-doped cuprates is qualitatively explained as a band reconstruction effect induced by carrier doping, besides the finalstate nonlocal screening from the Zhang-Rice singlet band.

Olfactory systems sense and respond to various odorants. Olfactory receptors, which in most organisms are G protein (heterotrimeric guanine nucleotide-binding protein)-coupled receptors, directly bind volatile or soluble odorants. Compared to the genomes of mammals, the genome of the nematode Caenorhabditis elegans contains more putative olfactory receptor genes, suggesting that in nematodes there may be combinatorial complexity to the receptor-odor relationship. We used RNA interference (RNAi) screening to identify nematode olfactory receptors necessary for the response to specific odorants. This screening identified 194 candidate olfactory receptor genes linked to 11 odorants. Additionally, we identified SRI-14 as being involved in sensing high concentrations of diacetyl. Rescue and neuron-specific RNAi experiments demonstrated that SRI-14 functioned in ASH neurons, specific chemosensory neurons, resulting in avoidance responses. Calcium imaging revealed that ASH neurons responded to high diacetyl concentrations only, whereas another class of chemosensory neurons, AWA neurons, reacted to both low and high concentrations. Loss of SRI-14 function hampered ASH responses to high diacetyl concentrations, whereas loss of ODR-10 function reduced AWA responses to low odorant concentrations. Chemosensory neurons ectopically expressing SRI-14 responded to a high concentration of diacetyl. Thus, nematodes have concentration-dependent odor-sensing mechanisms that are segregated at the olfactory receptor and sensory neuron levels.