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The recent discovery of superconductivity in Nd$_{1-x}$Sr$_{x}$NiO$_2$ has drawn significant attention in the field. A key open question regards the evolution of the electronic structure with respect to hole doping. Here, we exploit x-ray absorption spectroscopy (XAS) and resonant inelastic x-ray scattering (RIXS) to probe the doping dependent electronic structure of the NiO$_2$ planes. Upon doping, a higher energy feature in Ni $L_3$ edge XAS develops in addition to the main absorption peak. By comparing our data to atomic multiplet calculations including $D_{4h}$ crystal field, the doping induced feature is consistent with a $d^8$ spin singlet state, in which doped holes reside in the $d_{x^2-y^2}$ orbitals, similar to doped single band Hubbard models. This is further supported by orbital excitations observed in RIXS spectra, which soften upon doping, corroborating with Fermi level shift associated with increasing holes in the $d_{x^2-y^2}$ orbital., 6 pages, 4 figures. Supplemental material included

Author(s): Pfau, H; Chen, SD; Hashimoto, M; Gauthier, N; Rotundu, CR; Palmstrom, JC; Fisher, IR; Mo, SK; Shen, ZX; Lu, D | Abstract: The hallmark of nematic order in iron-based superconductors is a resistivity anisotropy but it is unclear to which extent quasiparticle dispersions, lifetimes, and coherence contribute. While the lifted degeneracy of the Fe dxz and dyz dispersions has been studied extensively, only little is known about the two other factors. Here, we combine in situ strain tuning with ARPES and study the nematic response of the spectral weight in BaFe2As2. The symmetry analysis of the ARPES spectra demonstrates that the dxz band gains quasiparticle spectral weight compared to the dyz band for negative antisymmetric strain Δϵyy suggesting the same response inside the nematic phase. Our results are compatible with a different coherence of the dxz and dyz orbital within a Hund's metal picture. We also discuss the influence of orbital mixing.

We report time- and angle-resolved photoemission spectroscopy measurements on the Sb(111) surface. We observe band- and momentum-dependent binding-energy oscillations in the bulk and surface bands driven by $A_{1g}$ and $E_{g}$ coherent phonons. While the bulk band shows simultaneous $A_{1g}$ and $E_{g}$ oscillations, the surface bands show either $A_{1g}$ or $E_{g}$ oscillations. The observed behavior is reproduced by frozen-phonon calculations based on density-functional theory. This evidences the connection between electron-phonon coupling and coherent binding energy dynamics.

Heavy metal pollution in fine particulate matter (PM

The pseudogap, d-wave superconductivity and electron-boson coupling are three intertwined key ingredients in the phase diagram of the cuprates. Sr_{2}IrO_{4} is a 5d-electron counterpart of the cuprates in which both the pseudogap and a d-wave instability have been observed. Here, we report spectroscopic evidence for the presence of the third key player in electron-doped Sr_{2}IrO_{4}: electron-boson coupling. A kink in nodal dispersion is observed with an energy scale of ∼50 meV. The strength of the kink changes with doping, but the energy scale remains the same. These results provide the first noncuprate platform for exploring the relationship between the pseudogap, d-wave instability, and electron-boson coupling in doped Mott insulators.

The superconducting dome of most iron-based superconductors emerges from a phase with nematic and magnetic ordering. However, the multiband and multiorbital nature of iron-based superconductors as well as twinning effects pose challenges to fully characterize the implications of these two ordering phenomena for the band structure. Here, the authors report high-quality ARPES measurements on twinned and detwinned BaFe${}_{2}$As${}_{2}$ and present a comprehensive and systematic overview of the band structure in the normal and the magnetically ordered states of this prototype parent compound.

We report an angle-resolved photoemission spectroscopy study of the iron-based superconductor family, Ba_{1-x}Na_{x}Fe_{2}As_{2}. This system harbors the recently discovered double-Q magnetic order appearing in a reentrant C_{4} phase deep within the underdoped regime of the phase diagram that is otherwise dominated by the coupled nematic phase and collinear antiferromagnetic order. From a detailed temperature-dependence study, we identify the electronic response to the nematic phase in an orbital-dependent band shift that strictly follows the rotational symmetry of the lattice and disappears when the system restores C_{4} symmetry in the low temperature phase. In addition, we report the observation of a distinct electronic reconstruction that cannot be explained by the known electronic orders in the system.

Author(s): He, Y; Wu, S; Song, Y; Lee, WS; Said, AH; Alatas, A; Bosak, A; Girard, A; Souliou, SM; Ruiz, A; Hepting, M; Bluschke, M; Schierle, E; Weschke, E; Lee, JS; Jang, H; Huang, H; Hashimoto, M; Lu, DH; Song, D; Yoshida, Y; Eisaki, H; Shen, ZX; Birgeneau, RJ; Yi, M; Frano, A | Abstract: We report a persistent low-energy phonon broadening around qB∼0.28 reciprocal lattice unit (r.l.u.) along the Cu-O bond direction in the high-Tc cuprate Bi2Sr2CaCu2O8+δ (Bi-2212). We show that such broadening exists both inside and outside the conventional charge-density wave (CDW) phase, via temperature-dependent measurements in both underdoped and heavily overdoped samples. Combining inelastic hard x-ray scattering, diffuse scattering, angle-resolved photoemission spectroscopy, and resonant soft x-ray scattering at the Cu L3-edge, we exclude the presence of a CDW in the heavily overdoped Bi-2212 similar to that observed in the underdoped systems. Finally, we discuss the origin of such anisotropic low-energy phonon broadening and its potential precursory role to the CDW phase in the underdoped region.

High temperature cuprate superconductors consist of stacked CuO2 planes, with primarily two dimensional electronic band structures and magnetic excitations, while superconducting coherence is three dimensional. This dichotomy highlights the importance of out-of-plane charge dynamics, believed to be incoherent in the normal state, yet lacking a comprehensive characterization in energy-momentum space. Here, we use resonant inelastic x-ray scattering (RIXS) with polarization analysis to uncover the pure charge character of a recently discovered collective mode in electron-doped cuprates. This mode disperses along both the in- and, importantly, out-of-plane directions, revealing its three dimensional nature. The periodicity of the out-of-plane dispersion corresponds to the CuO2 plane distance rather than the crystallographic c-axis lattice constant, suggesting that the interplane Coulomb interaction drives the coherent out-of-plane charge dynamics. The observed properties are hallmarks of the long-sought acoustic plasmon, predicted for layered systems and argued to play a substantial role in mediating high temperature superconductivity., Comment: This is the version of first submission. The revised manuscript according to peer reviews is now accepted by Nature and will be published online on 31st Oct., 2018

We present a combined ultrafast optical pump-probe and ultrafast x-ray diffraction measurement of the CDW dynamics in SmTe$_3$ at 300 K. The ultrafast x-ray diffraction measurements, taken at the Linac Coherent Light Source reveal a $\sim 1.55$ THz mode that becomes overdamped with increasing fluence. We identify this oscillation with the lattice component of the amplitude mode. Furthermore, these data allow for a more clear identification of the frequencies present in the optical pump-probe data. In both, reflectivity and diffraction, we observe a crossover of the response from linear (for small displacements) to quadratic in the amplitude of the order parameter displacement. Finally, a time-dependent Ginzburg-Landau model captures the essential features of the experimental observations., Comment: 7 pages, 5 figures

Fibroblast growth factor 23(FGF23) is a bone-derived hormone which regulates mineral homeostasis but may also have a role in cardiovascular disease. Here, we found that higher plasma FGF23 was independently associated with decreased heart rate variability in stage 5 CKD patients and parathyroidectomy may reverse these abnormal indicators. Lower heart rate variability (HRV) in patients with chronic kidney disease (CKD) compared with healthy controls is associated with increased risk of cardiovascular disease (CVD). Higher levels of plasma FGF23 also predict higher risk of CVD. Here, we aimed to evaluate the relationship between plasma FGF23 levels and HRV in patients with stage 5 CKD and to investigate longitudinal changes of them together with the correlation between their changes in two severe secondary hyperparathyroidism (SHPT) subgroups with successful parathyroidectomy (PTX) and persistent SHPT. This cross-sectional study included 100 stage 5 CKD patients, 78 controls, and a prospective study in two PTX subgroups classified as successful PTX (n = 24) and persistent SHPT (n = 4) follow-up. Blood examination and 24-h Holter monitoring for HRV were measured. Most HRV indices were lower in stage 5 CKD patients than in healthy controls, and plasma FGF23 levels were higher. In multivariate stepwise regression models, levels of plasma FGF23 and serum parathyroid hormone (PTH) were correlated with HRV. The successful PTX subgroup had significant improvements over baseline in HRV indices. Persistent SHPT subgroup had numerically similar changes in HRV indices. However, plasma FGF23 levels decreased in both subgroups. Plasma FGF23 levels were higher in CKD patients than in controls, much higher in patients with severe SHPT. FGF23 was independently associated with decreased HRV in stage 5 CKD. Successful PTX may reverse these abnormal indicators and contribute to decreases in the risk of cardiovascular disease.

Summary Length–weight relationships (LWRs) of three Chinese endemic fish species (Gymnocypris eckloni eckloni Herzenstein, 1891, Platypharodon extremus Herzenstein, 1891 and Triplophysa pseudoscleroptera (Zhu & Wu, 1981)) were analyzed, collecting from the upper Yellow River (Xunhua and Guide Counties, Qinghai Province). Totally 347 specimens monthly collected by gill nets with 40 mm mesh size and traps with 5 m length from August to October 2014, were used to estimate the relationship parameters. The allometric factor b values ranged from 2.96 in T. pseudoscleroptera to 3.33 in G. eckloni eckloni. The condition factor a values varies between 0.0063 and 0.0175 in three species. Three WLRs of fishes distributed in the upper Yellow River were firstly reported and will fill in some of the empty spaces on endemic species in the Fishbase.

We use ultrafast resonant x-ray diffraction to study the magnetic order in CuO under conditions of high electronic excitation. By measuring changes in the spectral shape of the Cu2+ magnetic (1/2 0 â1/2) reflection we investigate how an intense optical pump pulse perturbs the electronic and magnetic states. We observe an energy shift in the magnetic resonance at short times after the pump pulse. This shift is compared with expectations from band structure calculations at different electronic temperatures. This spectral line shift indicates that although the electrons are heated to effective electron temperatures far above TN on a time scale faster than the experimental resolution, magnetic order persists in this highly excited state for several hundred femtoseconds. © 2014 American Physical Society.

The relationship between the superconducting gap and the pseudogap has been the subject of controversies. In order to clarify this issue, we have studied the superconducting gap and pseudogap of the $\text{high}\ensuremath{-}{T}_{c}$ superconductor ${\mathrm{La}}_{2\ensuremath{-}x}{\mathrm{Sr}}_{x}{\mathrm{CuO}}_{4}$ ($x=0.10,14$) by angle-resolved photoemission spectroscopy (ARPES). Through the analysis of the ARPES spectra above and below ${T}_{c}$, we have identified a superconducting coherence peak even in the antinodal region on top of the pseudogap of a larger energy scale. The superconducting peak energy nearly follows the pure $d$-wave form. The $d$-wave order parameter ${\mathrm{\ensuremath{\Delta}}}_{0}$ [defined by $\mathrm{\ensuremath{\Delta}}(k)={\mathrm{\ensuremath{\Delta}}}_{0}(cos{k}_{x}a\ensuremath{-}cos{k}_{y}a)$ ] for $x=0.10$ and 0.14 are nearly the same, ${\mathrm{\ensuremath{\Delta}}}_{0}\ensuremath{\sim}12--14\phantom{\rule{0.28em}{0ex}}\mathrm{meV}$, leading to strong coupling $2{\mathrm{\ensuremath{\Delta}}}_{0}/{k}_{B}{T}_{c}\ensuremath{\sim}10$. The present result indicates that the pseudogap and the superconducting gap are distinct phenomena and can be described by the ``two-gap'' scenario.

We present a systematic angle-resolved photoemission spectroscopy study of the substitution dependence of the electronic structure of Rb_{0.8}Fe_{2}(Se_{1-z}S_{z})_{2} (z=0, 0.5, 1), where superconductivity is continuously suppressed into a metallic phase. Going from the nonsuperconducting Rb_{0.8}Fe_{2}S_{2} to superconducting Rb_{0.8}Fe_{2}Se_{2}, we observe little change of the Fermi surface topology, but a reduction of the overall bandwidth by a factor of 2. Hence, for these heavily electron-doped iron chalcogenides, we have identified electron correlation as explicitly manifested in the quasiparticle bandwidth to be the important tuning parameter for superconductivity, and that moderate correlation is essential to achieving high T_{C}.

We show that graphene deposited on a substrate has a non-negligible density of atomic scale defects. This is evidenced by a previously unnoticed D peak in the Raman spectra with intensity of about 1% with respect to the G peak. We evaluated the effect of such impurities on electron transport by mimicking them with hydrogen adsorbates and measuring the induced changes in both mobility and Raman intensity. If the intervalley scatterers responsible for the D peak are monovalent, their concentration is sufficient to account for the limited mobilities achievable in graphene on a substrate., version 2: several comments are taken into account and refs added

Single-crystal tetragonal α-MnO2 nanotubes have been successfully synthesized by a facile hydrothermal treatment of KMnO4 in the hydrochloric acid solution. The sample has been characterized by X-ray powder diffraction, field emission scanning electron microscopy, transmission electron microscopy, and orientation dependent Raman spectroscopy, which indicates the nanotubes have high-quality crystalline and shape-dependent optical properties. The morphology evolution of the sample reveals that the nanotubes are formed via the solid nanorod by a chemical etching process.

The objective of this study is to evaluate the long-term efficacy and safety of rituximab combined with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) in Chinese patients with newly diagnosed diffuse large B cell lymphoma (DLBCL). The study comprised a retrospective analysis of patients treated at a single center. Patients received four to six infusions of rituximab (375 mg/m(2) per dose) on day 1 of each cycle of CHOP chemotherapy. CHOP was initiated on day 3 of each cycle; cycles were repeated at 21-day intervals. A total of 82 patients with a median age of 45 years (range 18-76 years) was included. The overall response (OR) and complete response (CR) rates were 90.2 and 70.7%, respectively. The estimated 5-year progression-free survival (PFS) and overall survival (OS) rates were 56.4 +/- 8.3% and 74.1 +/- 7.4%, respectively. Patients with International Prognostic Index (IPI) scoresor = 2 had significantly higher OR, CR, PFS, and OS rates (p = 0.01, p = 0.02, p = 0.01, p0.001, respectively) compared with patients with IPI scores2. The hematologic toxicity was mild. Five patients with a history of chronic hepatitis B experienced a reactivation of viral hepatitis. The rituximab-CHOP combination was effective and well tolerated in Chinese patients with newly diagnosed DLBCL.

We present oxygen abundances of dwarfs in the young open cluster IC 4665 deduced from the OI $\lambda$7774 triplet lines and of dwarfs in the open cluster Pleiades derived from the [OI] $\lambda$6300 forbidden line. Stellar parameters and oxygen abundances were derived using the spectroscopic synthesis tool SME (Spectroscopy Made Easy). We find a dramatic increase in the upper boundary of the OI triplet abundances with decreasing temperature in the dwarfs of IC 4665, consistent with the trend found by Schuler et al. in the open clusters Pleiades and M 34, and to a less extent in the cool dwarfs of Hyades (Schuler et al. 2006a) and UMa (King & Schuler 2005). By contrast, oxygen abundances derived from the [OI] $\lambda$6300 forbidden line for stars in Pleiades and Hyades (Schuler et al. 2006b) are constant within the errors. Possible mechanisms that may lead a varying oxygen triplet line abundance are examined, including systematic errors in the stellar parameter determinations, the NLTE effects, surface activities and granulation. The age-related effects stellar surface activities (especially the chromospheric activities) are suggested by our analysis to blame for the large spreads of oxygen triplet line abundances., Comment: 11 pages, 5 figures. ApJ in press

A tunable flat lens is demonstrated based on reconfigurable metasurface, which is realized via changing the phase gradient of the metasurface in sub-wavelength level. The sub-wavelength metamolecules are formed by enclosing a liquid metal plug within microfluidic cavities, which can be tuned by changing the geometry of the metamolecules. The tunable flat lens is consisted of soft material with controllable functionalities. In simulation, the tuning of the focal length from 5 λ to 7 λ is demonstrated as the proof of concept. This reconfigurable metasurface can be used as a standard guideline to design different electromagnetic wave manipulation systems in realizing the dynamic control of beam steering, anti-reflection and focusing functionalities etc.

We present a systematic angle-resolved photoemission spectroscopy study of the substitution dependence of the electronic structure of Rb_{0.8}Fe_{2}(Se_{1-z}S_{z})_{2} (z=0, 0.5, 1), where superconductivity is continuously suppressed into a metallic phase. Going from the nonsuperconducting Rb_{0.8}Fe_{2}S_{2} to superconducting Rb_{0.8}Fe_{2}Se_{2}, we observe little change of the Fermi surface topology, but a reduction of the overall bandwidth by a factor of 2. Hence, for these heavily electron-doped iron chalcogenides, we have identified electron correlation as explicitly manifested in the quasiparticle bandwidth to be the important tuning parameter for superconductivity, and that moderate correlation is essential to achieving high T_{C}.

Recently, novel endothelins like zibotentan and atrasentan and other novel taxanes have been introduced to treat prostate cancer. This study reviews zibotentan in the treatment of castration-resistant prostate cancer (CRPC) and derives a more precise estimate of their effect of treatment.Two reviewers searched and extracted data of the published trials and review articles on zibotentan for prostate cancer using the Medline, Embase and Cochrane Controlled Trials Register database. We used hazard ratios (HRs) to assess the effects on overall survival (OS), progression-free survival (PFS), or time to PSA progression (TTP), and relative risk (RR) for the different types of toxicity. Four randomized controlled trials were identified.The pooled HR showed that zibotentan did not improve OS and PFS (HR = 0.92, 95%CI = 0.82-1.03, p = 0.161, HR = 0.98, 95% CI = 0.89-1.08, p = 0.714). Zibotentan had modest benefits on TTP (HR = 0.94, 95% CI = 0.91-0.97, p = 0.001). In addition, zibotentan led to more peripheral edema, anemia, cardiac failure and pneumonia.Our study concludes that zibotentan is not an attractive option for CRPC patients. However, additional studies on other novel therapies are needed to improve patient outcomes.

We report the detection of a cool stellar component at the center of the planetary nebula (PN) Me 1-1 and present optical spectra of the system. From measurements of nebular emission lines, we have derived electron temperature, density and chemical composition. Heavy elemental abundances deduced from collisionally excited lines (CELs) are compared with those derived from optical recombination lines (ORLs). The electron temperature and density deduced from the nebular analysis were used to calculate the nebular continuum emission, which was then subtracted from the observed spectrum in order to obtain the spectrum of the cool stellar component apparent in the observed spectrum. We calculate B and V magnitudes of the cool companion and obtain a color index of B − V = 1.20. By comparing the spectrum of the cool star with standard spectra in Pickles's 1998 Stellar Flux Library, we find that the cool component has the spectral type of a K3-4 bright giant. Our analysis suggests that Me 1-1 is probably a yellow symbiotic system.

Electronic evolution from an antiferromagnet to a high-Tc superconductor is revealed by angle-resolved photoemission experiments on tetragonal Ca(1.9)Na(0.1)CuO(2)Cl(2) single crystals, which were successfully grown for the first time under high pressures. In this underdoped superconductor, we found clear fingerprints of the parent insulator: a shadow band and a large pseudo-gap. These observations are most likely described by a "chemical potential shift", which contrasts clearly with the prevailing wisdom of the "pinned chemical potential" learned from the prototype La(2-x)Sr(x)CuO(4), demonstrating that the route to a high-Tc superconductor is not unique., Comment: 4 pages, 4 figures

Raman spectroscopy was applied to study β-haematin, normal erythrocytes, parasite-infected erythrocytes, and lysed samples of the parasite-infected erythrocytes. Differences were observed between spectra excited by the Ar+ laser and those excited by the HeNe laser. The significant difference lies in the fact that with the HeNe laser excitation at 632.8 nm, band absorption is a result of the charge transfer, while laser excitation in Qv-absorption bands of the active site of the haem1 occurs for the Ar+ laser. Similarity in the spectra of β-haematin and parasite-infected erythrocyte was observed with the HeNe laser. The differences between the normal erythrocyte and the parasite-infected erythrocyte may still be distinguished by the band at 754 cm−1 for the parasite-infected erythrocyte. In addition, with the HeNe laser, the band at 1080 cm−1 may also be used as a reference to whether the erythrocyte has been infected.

We have performed an angle-resolved photoemission spectroscopy (ARPES) study of ${\mathrm{BaNi}}_{2}{P}_{2}$ that shows a superconducting transition at ${T}_{c}$ $\ensuremath{\sim}$ 2.5 K. We observed hole and electron Fermi surfaces (FSs) around the Brillouin zone center and corner, respectively, and the shapes of the hole FSs dramatically changed with photon energy, indicating strong three dimensionality. The observed FSs are consistent with band-structure calculations and de Haas-van Alphen measurements. The mass enhancement factors estimated in the normal state were ${m}^{*}$/${m}_{b}$ $\ensuremath{\le}$ 2, indicating weak electron correlation compared to typical iron-pnictide superconductors. An electronlike Fermi surface around the $Z$ point was observed in contrast with BaNi${}_{2}$As${}_{2}$ and may be related to the higher ${T}_{c}$ of ${\mathrm{BaNi}}_{2}{P}_{2}$.

We report findings of strong anomalies in both mutual inductance and inelastic Raman spectroscopy measurements of single-unit-cell FeSe film grown on Nb-doped SrTiO3, which occur near the temperature where the superconductinglike energy gap opens. Analysis suggests that the anomaly is associated with a broadened ferroelectric transition in a thin layer near the FeSe/SrTiO3 interface. The coincidence of the ferroelectric transition and gap-opening temperatures adds credence to the central role played by the film-substrate interaction on the strong Cooper pairing in this system. We discuss scenarios that could explain such a coincidence.

We report particle-hole pair excitations in a cuprate insulator in the intermediate regimes of momentum-transfers using high energy inelastic x-ray scattering. The excitation spectra show dispersive features near the Mott edge which shed light on the momentum structure of the upper Hubbard band in cuprates. We briefly discuss the potential use of such a technique to study the momentum dependence of unoccupied bands and q-dependent charge fluctuations in complex insulators.

The electronic structure of heavily overdoped Bi2Sr2CaCu2O8+delta is investigated by angle-resolved photoemission spectroscopy. The long-sought bilayer band splitting in this two-plane system is observed in both normal and superconducting states, which qu

With significantly improved sample quality and instrumental resolution, we clearly identify in the ( pi,0) photoemission spectra from YBa(2)Cu(3)O(6.993), in the superconducting state, the long-sought "peak-dip-hump" structure. This advance allows us to investigate the large a-b anisotropy of the in-plane electronic structure including, in particular, a 50% difference in the magnitude of the superconducting gap that scales with the energy position of the hump feature. This anisotropy, likely induced by the presence of the CuO chains, raises serious questions about attempts to quantitatively explain the YBa(2)Cu(3)O(7-delta) data from various experiments using models based on a perfectly square lattice.

The charge dynamics in weakly hole doped high temperature superconductors is studied in terms of the accurate numerical solution to a model of a single hole interacting with a quantum lattice in an antiferromagnetic background, and accurate far-infrared ellipsometry measurements. The experimentally observed two electronic bands in the infrared spectrum can be identified in terms of the interplay between the electron correlation and electron-phonon interaction resolving the long standing mystery of the mid-infrared band.

We have performed angle-resolved photoemission spectroscopy study of the electronic structure of the tri-layer high- T c cuprate superconductor Bi 2 Sr 2 Ca 2 Cu 3 O 10 + δ and observed separate band dispersions and Fermi surfaces corresponding to the outer and inner CuO2 planes. From the band dispersions, the c-axis hopping parameter t ⊥ between the outer and inner CuO2 planes is estimated to be ∼56 meV.