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2021年第5版WHO中枢神经系统肿瘤新分类的胶质神经元和神经元肿瘤部分引入更多分子遗传学标准；新增了少突胶质细胞瘤样特征和核簇的弥漫性胶质神经元肿瘤、黏液样胶质神经元肿瘤、多结节空泡状神经元肿瘤；废弃了间变性神经节细胞胶质瘤；副神经节瘤归入颅神经及椎旁神经肿瘤。本文对以上变更作简要解读。.

Glioma is one of the most common central nervous system tumors in children.Increasing studies show that compared with adults, some gliomas in children have unique molecular genetic characteristics and completely different biological behaviors, although they are similar to adults in morphology and nomenclature. Therefore, pediatric glioma is by no means a "miniature version" of adults. In the 5th edition of WHO classification of central nervous system tumors published in the end of 2021, one of the most important revisions is the division of the classification into adult-type and pediatric-type diffuse gliomas, and the latter is further divided into pediatric-type diffuse low-grade gliomas and pediatric-type diffuse high-grade gliomas. In addition to histological morphology and clinical features, the basis of classification includes more molecular features. Therefore, in clinical practice, we need to pay more attention to the significance of molecular pathological diagnosis in the diagnosis and treatment of gliomas in children.胶质瘤是儿童常见的中枢神经系统肿瘤之一。越来越多的研究显示与成人相比，有些肿瘤尽管在形态学上与成人表现相似，诊断名称也一样，但却具有独特的分子遗传学特征及完全不同的生物学行为，因此儿童的脑胶质瘤绝非成人的“微缩版”。2021年末发布的第5版世界卫生组织中枢神经系统肿瘤分类中，相当重要的修订之一就是将儿童常见的一些弥漫性胶质瘤单独区分开来，并进一步分成了儿童型弥漫性低级别胶质瘤和儿童型弥漫性高级别胶质瘤两大类。而分类的依据除了组织学形态和临床特点，更多地包含了分子特征。因此医师在临床实践中，一定要重视分子病理诊断对儿童胶质瘤诊治的重要意义。.

Though the incidence of sudden sensorineural hearing loss (SSNHL) is relatively low, the disorder has a major impact on the quality of life of patients. Identifying biological markers for the disease will be useful, especially in resource-scarce areas. Our study aims to evaluate the correlation between the degree of hearing impairment and glycosylated hemoglobin (HbA1c) in patients with SSNHL.One hundred and thirty-eight patients with SSNHL and no history of diabetes were included in this study. The intravenous HbA1c content before treatment was correlated with the pure tone audiogram (PTA) average as per the criteria for SSNHL. Spearman correlation and the Receiver Operating Characteristic (ROC) curve were used to determine the HbA1c levels of the study participants. The critical value of HbA1c and its diagnostic implications for assessing the degree of hearing impairment in patients with SSNHL were noted.There was a significant positive correlation between HbA1c and PTA in patients with SSNHL (p0.05). In addition, the best HbA1c cutoff value for screening and referring an individual for a detailed audiometric evaluation of hearing impairment was 5.550%, as indicated by the ROC curve.The level of HbA1c in the circulation may affect the onset, duration, and progression of SSNHL. The same parameter may be used as a diagnostic and prognostic indicator for this condition.

Primary hepatocellular carcinoma is one of the most common high-grade malignant tumors in the world. Its incidence ranks fifth among malignant tumors in China, and various therapeutic measures have poor curative effect. Pyruvate kinase type M2 is a key enzyme in the glycolytic pathway, and its abnormal expression in liver cancer is closely related to the proliferation, metastasis, diagnosis, treatment, prognosis, as well as drug and radiation resistance. Therefore, multi-pathway targeted regulation of pyruvate kinase type M2 use is expected to become a new direction for the treatment of primary liver cancer.原发性肝细胞癌是世界上常见、恶性程度很高的肿瘤之一，在中国恶性肿瘤中发病率排第5位，肝癌的各种治疗措施疗效不佳。M2型丙酮酸激酶作为糖酵解途径关键酶，它的异常表达与肝癌的增殖、转移、诊断、治疗及预后密切相关，与肝癌药物治疗的耐药和放射线抗拒也有关联，采用多种途径靶向调控肝癌细胞的M2型丙酮酸激酶，有望成为治疗原发性肝癌的一个新方向。.

The isovalent-substituted iron pnictide compound SrFe$_{2}$(As$_{1-x}$P$_{x}$)$_{2}$ exhibits multiple evidence for nodal superconductivity via various experimental probes, such as the penetration depth, nuclear magnetic resonance and specific heat measurements. The direct identification of the nodal superconducting (SC) gap structure is challenging, partly because the presence of nodes is not protected by symmetry but instead caused by an accidental sign change of the order parameter, and also because of the three-dimensionality of the electronic structure. We have studied the SC gaps of SrFe$_{2}$(As$_{0.65}$P$_{0.35}$)$_{2}$ in three-dimensional momentum space by synchrotron and laser-based angle-resolved photoemission spectroscopy. The three hole Fermi surfaces (FSs) at the zone center have SC gaps with different magnitudes, whereas the SC gaps of the electron FSs at the zone corner are almost isotropic and $k_{z}$-independent. We propose that the SC gap of the outer hole FS changes sign around the Z-X [($0, 0, 2\pi$)-($\pi,\pi, 2\pi$)] direction., Comment: This is a pre-print of an article published in Scientific Reports. The final authenticated version is available online at: https://doi.org/10.1038/s41598-019-52887-y

随着神经影像学技术和神经外科技术尤其是外科手术机器人的发展和应用，立体定向活检手术逐渐成为神经系统疑难病例精确诊断的有力手段。病理科将接收越来越多的活检小标本，并面对各种各样的非肿瘤性病变以及处于早期的病变。病理医师如何迎接挑战，突破瓶颈？该文从神经病理基本病变的识别，紧密结合临床、影像及实验室检查以及密切关注分子生物学新进展三方面介绍作者在神经病理诊断实践中的体会。.

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.

临床神经病理学作为神经病学和病理学的桥梁学科，其亚专科建设是临床病理医师规范化培训和继续教育的重要组成部分，也在神经内科、神经外科及神经影像等相关专业医师的培训中起着重要的作用。本文从神经病理基本功的训练、病理与临床的结合、病理与影像的结合以及专业知识的更新四个方面阐述了临床神经病理学亚专科建设的重点。临床神经病理诊断水平的高低直接关系着神经系统疾病的临床诊疗效果，以及神经系统疾病相关科学研究的客观性和可信度。做好临床神经病理学亚专科的建设才能从根本上提升临床神经病理诊断的水平，助力我国脑科学的进步。.

Author(s): Sreedhar, SA; Rossi, A; Nayak, J; Anderson, ZW; Tang, Y; Gregory, B; Hashimoto, M; Lu, DH; Rotenberg, E; Birgeneau, RJ; Greven, M; Yi, M; Vishik, IM | Abstract: The lamellar cuprate superconductors exhibit the highest ambient-pressure superconducting transition temperatures (Tc), and after more than three decades of extraordinary research activity, continue to pose formidable scientific challenges. A major experimental obstacle has been to distinguish universal phenomena from materials- or technique-dependent ones. Angle-resolved photoemission spectroscopy (ARPES) measures momentum-dependent single-particle electronic excitations and has been invaluable in the endeavor to determine the anisotropic momentum-space properties of the cuprates. HgBa2CuO4+δ (Hg1201) is a single-CuO2-layer cuprate with a particularly high optimal Tc and a simple crystal structure, yet there exists little information from ARPES about the electronic properties of this model system. Here we present an ARPES study of doping-, temperature-, and momentum-dependent systematics of near-nodal dispersion anomalies in Hg1201. The data reveal a hierarchy of three distinct energy scales: a subgap low-energy kink, an intermediate-energy kink near 55 meV, and a peak-dip-hump structure. The first two features are attributed to the coupling of electrons to Ba-derived optical phonons and in-plane bond-stretching phonons, respectively. The nodal peak-dip-hump structure appears to have a common doping dependence in several single-layer cuprates and is interpreted as a manifestation of pseudogap physics at the node. These results establish several universal phenomena, both in terms of connecting multiple experimental techniques for a single material and in terms of connecting comparable spectral features in multiple structurally similar cuprates.

Quantum well states appear in metallic thin films due to the confinement of the wave function by the film interfaces. Using angle-resolved photoemission spectroscopy, we unexpectedly observe quantum well states in fractured single crystals of CeCoIn$_5$. We confirm that confinement occurs by showing that these states' binding energies are photon-energy independent and are well described with a phase accumulation model, commonly applied to quantum well states in thin films. This indicates that atomically flat thin films can be formed by fracturing hard single crystals. For the two samples studied, our observations are explained by free-standing flakes with thicknesses of 206 and 101 \r{A}. We extend our analysis to extract bulk properties of CeCoIn$_5$. Specifically, we obtain the dispersion of a three-dimensional band near the zone center along in-plane and out-of-plane momenta. We establish part of its Fermi surface, which corresponds to a hole pocket centered at $\Gamma$. We also reveal a change of its dispersion with temperature, a signature that may be caused by the Kondo hybridization., Comment: 11 pages, 8 figures

To explore the expression and biological functions of linc00337 in colorectal cancer (CRC), as well as its underlying mechanism.The relative expression of linc00337 in 47 cases of CRC tissues and cells was detected via quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR). The si-linc00337 interference sequences were designed and transiently transfected into CRC cells. The interference efficiency was detected via qRT-PCR. Regulatory effect of linc00337 on proliferation of CRC cells was detected via colony formation assay. Cell cycle distribution and apoptosis rate after interference in linc00337 expression were determined using flow cytometry. Moreover, the effects of linc00337 knockdown on cell migration and invasion were detected using transwell assay. At last, the effect of si-linc00337 on the MEK/ERK signaling pathway was detected using Western blotting.The results of qRT-PCR showed that among the 47 cases of CRC tissues, the expression of linc00337 was up-regulated in 40 cases. Similarly, it was highly expressed in CRC cell lines. The results of colony formation assay manifested that cell proliferation declined after interference in linc00337 expression. The results of flow cytometry and transwell assay showed that interference in linc00337 expression arrested the cell cycle in G1/G0 phase, increased the apoptosis rate, and inhibited the invasion and migration of CRC cells. According to the results of Western blotting, expressions of molecular markers in the MEK/ERK pathway after interference in linc00337 expression were significantly changed.Linc00337 is up-regulated in CRC tissues and cells. Interference in linc00337 expression can inhibit cell proliferation, migration, and invasion and promote apoptosis through the MEK/ERK pathway.

Homogenisation has been used to eliminate solute segregation of CrMnFeCoNi high-entropy alloys (HEAs) before thermomechanical processing. To overcome the deficiencies caused by high-temperature homogenisation, we cancelled the homogenisation and studied the solute segregation feature and its effect on the grain growth and the mechanical property. The HEA forms equiaxed grains with the solute segregation in the range of tens of micrometres after cold rolling and recrystallisation. The grain growth in recrystallisation still abides by the classical grain growth kinetics, but with a higher power index of 3.33 and activation energy of 392.4 kJ mol−1 than those of the homogenised HEA, indicating a solute-drag effect. The relationship between the yield stress and grain size follows the Hall–Petch dependence with a higher intrinsic strength.

As a promising engineering material, high-entropy alloys (HEAs) CrFeCoNi system has attracted extensive attention worldwide. Their cast alloys are of great importance because of their great formability of complex components, which can be further improved through the transition of the columnar to equiaxed grains and grain refinement. In the current work, the influence of C contents on the grain structures and mechanical properties of the as-cast high-entropy alloy CrFeCoNi was chosen as the target and systematically studied via a hybrid approach of the experiments and thermodynamic calculations. The alloys with various C additions were prepared by arc melting and drop cast. The as-cast macrostructure and microstructure were characterized using optical microscopy, scanning electron microscopy, and transmission electron microscopy. The cast HEAs transform from coarse columnar grains into equiaxed grains with the C level increased to ≥ 2 at. pct and the size of equiaxed grains is further decreased with the increasing C addition. It is revealed that the interdendritic segregation of Cr and C results in grain boundary precipitation of M23C6 carbides. The grain refinement is attributed to the additional constitutional supercoiling from the C addition. The yield stress and tensile strength at room temperature are improved due to the transition of columnar to equiaxed grains and grain refinement.

Within the ultra-relativistic quantum molecular dynamics (UrQMD) model, in which the Lorentz-covariant treatment of nuclear mean-field potential is considered, the fluctuations of net-baryon, net-charge and deuterons multiplicity distributions in Au+Au head-on collisions at $\sqrt{s_{NN}}=3.0-5.0$ GeV are calculated. The results show that the nuclear mean-field potential can significantly enhance the magnitude of baryon number fluctuations in narrow rapidity windows, and this enhancement rapidly weakens with increasing beam energy. However, for proton and net-charge number fluctuations, the mean-field effects are less noticeable than that for baryon number. In addition, for net-charge number fluctuations, the negative binomial distribution agrees well with the calculated results at mid-pseudorapidity window. Finally, the event-by-event fluctuations of deuteron number in the coalescence production picture are calculated as well, it is found that its cumulant ratios decrease linearly with increasing the average multiplicity of deuterons per event, i.e., increase with increasing beam energy.

The pseudogap, $d$-wave superconductivity and electron-boson coupling are three intertwined key ingredients in the phase diagram of the cuprates. ${\mathrm{Sr}}_{2}{\mathrm{IrO}}_{4}$ 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 ${\mathrm{Sr}}_{2}{\mathrm{IrO}}_{4}$: electron-boson coupling. A kink in nodal dispersion is observed with an energy scale of $\ensuremath{\sim}50\text{ }\text{ }\mathrm{meV}$. 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 shape evolutions of the even-even cadmium isotopes $^{110--116}\mathrm{Cd}$ are investigated in this work. The giant monopole resonances built on different shape isomeric states are studied using the quasiparticle random phase approximation, which is implemented with a finite amplitude method. We find the local minima corresponding to the prolate, oblate, and triaxial-deformed isomeric states in the even-even cadmium isotopes. Their responses to external monopole perturbations are quite different. Larger deformation tends to make the energy of the giant monopole resonance to shift lower. It is well known that the density functional models have some difficulties in predicting the right positions of the monopole resonances in cadmium isotopes: the centroid energies always seem too large compared to the experimental results. Our calculations show the giant monopole resonances built on the $\ensuremath{\gamma}$ soft isomeric states in the cadmium isotopes have centroid energies even lower than the experimental measurements. Therefore, if the isomeric branching of these $\ensuremath{\gamma}$ soft isomeric states turns out to be prominent, isomer mixing may be a good explanation to the longstanding puzzle.

横纹肌样肿瘤最初在肾脏被描述，之后报道了原发于中枢神经系统具有横纹肌样特征的肿瘤，并正式命名为不典型畸胎样/横纹肌样肿瘤，随着对此类肿瘤认识的不断提高及肿瘤分子机制的深入研究，2016年WHO颁布的新修订的中枢神经系统肿瘤分类又增加了上皮样型胶质母细胞瘤及具有横纹肌样特征的胚胎性肿瘤等新的肿瘤亚型。在中枢神经系统肿瘤的临床病理诊断中，这些不同类型的颅内肿瘤具有横纹肌样细胞形态特征，给病理医师的诊断及鉴别诊断带来了很多困扰。该文就具有这种形态的肿瘤进行分类阐述及讨论。.

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 pygmy dipole resonance (PDR) of $^{208}\mathrm{Pb}$ is studied with random phase approximation method. The effect of the neutron-proton mass splitting is discussed in the framework of relativistic mean field theory via including the scalar-isovector meson $\ensuremath{\delta}$ explicitly. The model is calibrated with nuclear bulk properties as well as finite nuclei data, and is further checked by terrestrial experimental and astrophysical constraints. The inclusion of $\ensuremath{\delta}$ meson reduces the neutron skin thickness of $^{208}\mathrm{Pb}$ as well as $^{48}\mathrm{Ca}$, which are turned out to be closely related. The energy of pygmy dipole resonance is in a large extent dominated by the excitations of neutrons near the Fermi surface. We found that the peak positions of the giant dipole resonance (GDR) and the PDR are sensitive to the nucleon-meson coupling in the scalar-isovector channel. A linear correlation between the neutron-proton effective mass splitting at saturation density and the relative offset of GDR and PDR is identified in $^{208}\mathrm{Pb}$.

In this study, the joints of dissimilar materials between S355JR carbon steel and 316L stainless steel were welded by gas tungsten arc welding (GTAW) multi-pass welding process. Characterisations of microstructure, mechanical properties and corrosion behaviours of dissimilar joint were investigated. The experimental results reveal that the microstructure of weld metal (WM) is austenite and vermiform δ-ferrite, and they cross-distribute in the weld seam. Moreover, there is a decarburisation layer on the interface of S355JR/WM, but the detrimental phase σ and M23C6 (chromium carbide) are not observed in the WM through X-ray diffraction. The fracture of the S355JR/316L welded joints always occurs in the S355JR heat affected zone during tensile test. Mechanical properties of the welded joints prepared by GTAW can meet the requirements of engineering application. The electrochemical corrosion test is also indicates that the corrosion resistance of WM decreases compared with the 316L base material. The corrosio...

Some mechanisms of creep, especially those involving dislocations for many crystalline materials, can be verified by direct microstructural examination. However, metallic glass thin films (MGTFs) are disordered materials lacking the long-range order of crystals. Even today, the creep mechanisms for amorphous alloys are far from being fully understood. The physical factors governing localization and instability during creep deformation are still elusive. In this work, Ni60Nb40 alloys with high kinetic stability were prepared by magnetron sputtering at different substrate temperatures to obtain MGTFs with different internal states. We report a close correlation between the internal states and the creep resistance of the MGTFs and reveal that altering the substrate temperature during magnetron sputtering can induce changes in the surface morphologies, plastic deformation resistance, and creep resistance of Ni60Nb40 MGTFs. The creep deformation mechanism is interpreted based on the shear transformation zone (STZ) model of amorphous alloys, and our results may have implications for understanding the role of STZs during creep deformation of MGTFs.

This paper studied the influences of mineral admixture content on the fluidity, compressive strength and vertical expansion rate of the cementitious grout, which based on a ternary composite cementitious material system of sulfoalminate cement, protland cement and gypsum. The influences of fly ash, slag powder and silica fume were investigated respectively. It was shown that: (1) The initial fluidity grew as the addition of fly ash content in the cementitious grout, 1 d compressive strength and 3 d compressive strength were reduced. (2) The slag powder had great impact on the fluidity, when the content of slag powder more than 18%, initial and 30 min fluidities declined. With the slag powder increased, 1 d, 3 d and 28 d compressive strengths decreased slightly, while 3 h vertical expansion rate increased. (3) The increased of silica fume content made the compressive strengths rised first and then fell. 1 d, 3 d and 28 d compressive strengths could reach their maximum values, when the amount of silica fume was 3.0%.

We studied the electronic structure of the heavy-fermion compound $\mathrm{Yb}{({\mathrm{Ru}}_{1\ensuremath{-}x}{\mathrm{Rh}}_{x})}_{2}{\mathrm{Ge}}_{2}$ with $x=0$ and nominally $x=0.125$ using ARPES and LDA calculations. We find a valence band structure of Yb corresponding to a noninteger valence close to $3+$. The three observed crystal electric field levels with a splitting of 32 and 75 meV confirm the suggested configuration with a quasiquartet ground state. The experimentally determined band structure of the conduction electrons with predominantly Ru $4d$ character is well reproduced by our calculations. ${\mathrm{YbRu}}_{2}{\mathrm{Ge}}_{2}$ undergoes a nonmagnetic phase transition into a ferroquadrupolar ordered state below 10.2 K and then to an antiferromagnetically ordered state below 6.5 K. A small hole Fermi surface shows nesting features in our calculated band structure and its size determined by ARPES is close to the magnetic ordering wave vector found in neutron scattering. The transitions are suppressed when ${\mathrm{YbRu}}_{2}{\mathrm{Ge}}_{2}$ is doped with 12.5% Rh. The electron doping leads to a shift of the band structure and successive Lifshitz transitions.

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.

We study the interface effects in strangelets adopting mean-field approximation (MFA). Based on an equivparticle model, the linear confinement and leading-order perturbative interactions are included with density-dependent quark masses. By increasing the confinement strength, the surface tension and curvature term of strange quark matter (SQM) become larger, while the perturbative interaction does the opposite. For those parameters constrained according to the 2 M⊙ strange star, the surface tension is ∼2.4 MeV/fm2, while unstable SQM indicates a slightly larger surface tension. The obtained results are then compared with those predicted by the multiple reflection expansion (MRE) method. In contrast to the bag model case, it is found that MRE method overestimates the surface tension and underestimates the curvature term. To reproduce our results, the density of states in the MRE approach should be modified by proper damping factors.

The pygmy dipole resonance (PDR) of $^{68}\mathrm{Ni}$ was measured by Wieland et al. [Phys. Rev. Lett. 102, 092502 (2009)] through virtual photon scattering and Rossi et al. [Phys. Rev. Lett. 111, 242503 (2013)] through a photoneutron reaction. However, the PDR peaks are observed at different positions: 11 and 9.55(17) MeV respectively. Our calculation based on the deformed relativistic random phase approximation suggests that the discrepancy between these two measurements might be induced by the effect of the shape-coexistence isomeric state in $^{68}\mathrm{Ni}$.

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.

The finite-amplitude method is a feasible numerical approach to large scale random phase approximation calculations. It avoids the storage and calculation of residual interaction elements as well as the diagonalization of the RPA matrix, which will be prohibitive when the configuration space is huge. In this work we finished the implementation of a finite-amplitude method in a relativistic meson exchange mean field model with axial symmetry. The direct variation approach makes our FAM scheme capable of being extended to the multipole excitation case.

In the past decade, topological materials have been continuously attracting the interest of the condensed-matter physics community because of their unique band structures and transport properties. Recently, ZrTe${}_{5}$ is becoming a promising platform to study topological phase transitions, as it could possibly be a 3D Dirac semimetal, a 3D weak topological insulator (TI), or a 3D strong TI, which are distinguished by whether there is a finite band gap and whether there is a topological surface state (TSS). This paper performs a systematic high-momentum-resolution photoemission study on ZrTe${}_{5}$ using 6 eV photon energy. The conduction and valence bands near $\mathrm{\ensuremath{\Gamma}}$ are measured with a gap between 18 and 29 meV. The gap size is smaller than former studies. This work also examines the spectral difference at different photon energies, which is attributed to final-state effects and the 3D nature of the band structure. By doing so, the authors confirm the gap is not due to some specific out-of-plane momentum, and conclude that there is no TSS. The final-state interpretation also reconciles the discrepancies of previous studies regarding the existence of the TSS. Hence, the results are consistent with ZrTe${}_{5}$ being a 3D weak topological insulator.

Single unit cell films of iron selenide (1UC FeSe) grown on SrTiO3 (STO) substrates have recently shown superconducting energy gaps opening at temperatures close to the boiling point of liquid nitrogen (77 K), a record for iron-based superconductors. Towards understanding why Cooper pairs form at such high temperatures, a primary question to address is the role, if any, of the STO substrate. Here, we report high resolution angle resolved photoemission spectroscopy (ARPES) results which reveal an unexpected and unique characteristic of the 1UC FeSe/STO system: shake-off bands suggesting the presence of bosonic modes, most likely oxygen optical phonons in STO, which couple to the FeSe electrons with only small momentum transfer. Such coupling has the unusual benefit of helping superconductivity in most channels, including those mediated by spin fluctuations. Our calculations suggest such coupling is responsible for raising the superconducting gap opening temperature in 1UC FeSe/STO. This discovery suggests a pathway to engineer high temperature superconductors., 25 pages, 12 figures

Rapid detection of red imported fire ant (Solenopsis invicta Buren; Hymenoptera: Formicidae) nests is important in assessing the control efforts and for monitoring dispersal of this pest. In this study, spectroscopic techniques were employed to characterize the reflectance spectra of fire ant nest soil and the areas surrounding the nests. The results showed significant differences between nest soil, grass, and bare soil not disturbed by fire ant at the 680 nm wavelength of the electromagnetic spectrum. The reflectance of nest soil was 10% to 15% lower than that of the surrounding non-nest bare soil at wavelengths of 780 to 1000 nm. Furthermore, the reflectance of nest soil was significantly correlated with soil water content (R2 = 0.962). La deteccion rapida de los nidos de la hormiga de fuego roja importada (Solenopsis invicta Buren; Hymenoptera: Formicidae) es importante en el monitoreo del control y dispersion de esta plaga. En este estudio, se utilizo la tecnica espectroscopica en los nidos de la hormiga de fuego para detectar el espectro del reflejo enl suelo de los nidos y su alrededor. Los resultados mostraron diferencias significativas entre el suelo de los nidos, la grama, y de los nidos de otras especies de hormigas en suelo esteril a los 680 nm de longitud de onda del espectro electromagnetico. El reflejo del suelo de los nidos fue del 10% a 15% menor que el suelo esteril alrededor del nido a longitudes de onda de 780-1000 nm. Ademas, el reflejo del suelo del nido fue significativamente correlacionado con el contenido de agua del suelo (R2 = 0.962). View this article in BioOne