Strong band renormalization and emergent ferromagnetism induced by electron-antiferromagnetic-magnon coupling.

The interactions between electrons and antiferromagnetic magnons (AFMMs) are important for a large class of correlated materials. For example, they are the most plausible pairing glues in high-temperature superconductors, such as cuprates and iron-based superconductors. However, unlike electron-phonon interactions (EPIs), clear-cut observations regarding how electron-AFMM interactions (EAIs) affect the band structure are still lacking. Consequently, critical information on the EAIs, such as its strength and doping dependence, remains elusive. Here we directly observe that EAIs induce a kink structure in the band dispersion of Ba1-xKxMn2As2, and subsequently unveil several key characteristics of EAIs. We found that the coupling constant of EAIs can be as large as 5.4, and it shows strong doping dependence and temperature dependence, all in stark contrast to the behaviors of EPIs. The colossal renormalization of electron bands by EAIs enhances the density of states at Fermi energy, which is likely driving the emergent ferromagnetic state in Ba1-xKxMn2As2 through a Stoner-like mechanism with mixed itinerant-local character. Our results expand the current knowledge of EAIs, which may facilitate the further understanding of many correlated materials where EAIs play a critical role.

[Effect of dyslipidemia on clinical outcome of infertility patients receiving donor eggs].

Objective: To explore the effect of dyslipidemia on the clinical outcome of intracytoplasmic sperm injection-embryo transfer (ICSI-ET) in infertility patients receiving donor eggs. Methods: A total of 118 patients were selected to receive egg donors and ICSI-ET at the First Affiliated Hospital of Nanjing Medical University between April 2007 and December 2020. According to the levels of triacylglycerol, serum cholesterol, high density lipoprotein (HDL), and low density lipoprotein, they were divided into dyslipidemia group (35 cases) and normal blood lipids group (83 cases). The influence of body mass index (BMI) and age was adjusted by 1∶1 propensity score matching, and the general condition and clinical outcome of the two groups were analyzed retrospectively. Finally, the relationship between lipid composition and clinical outcome was analyzed according to patients' age and BMI. Results: (1) Comparing the pre-matching dyslipidemia group with the normal blood lipids group, the BMI of the dyslipidemia group was significantly higher than that of the normal blood lipids group [(23.5±2.4) vs (22.4±2.7) kg/m2], and the embryo implantation rate was significantly lower than that of the normal blood lipids group [13.6% (8/59) vs 27.3% (36/132)], the differences were statistically significant (both P<0.05). (2) There were no significant differences in years of infertility, number of pregnancies, number of abortions, number of transplanted embryos, protocol of endometrial preparation, endometrial thickness on transplantation day and high quality embryo rate between the two groups, through propensity score matching (all P>0.05). The biochemical pregnancy rate [28.6% (10/35)], embryo implantation rate [13.6% (8/59)] and live birth rate [20.0% (7/35)] in dyslipidemia group were significantly lower than those in the normal blood lipids group (P<0.05). The clinical pregnancy rate was lower than that of the normal blood lipids group (P>0.05). (3) The results of stratified analysis showed that the level of HDL in the clinically non-pregnant group was significantly lower than that in the pregnant group in patients ≤ 35 years old [(1.5±0.3) vs (1.8±0.5) mmol/L; P<0.05]. In the overweight recipient patients, the level of HDL of the clinically non-pregnant group was lower than that of the pregnant group (P>0.05). Conclusions: Dyslipidemia significantly reduces the biochemical pregnancy rate, embryo implantation rate and live birth rate in patients with receiving donor eggs. Especially in patients aged ≤35 years old, the reduction of HDL is closely related to adverse pregnancy outcomes.

Distinct Kondo Screening Behaviors in Heavy Fermion Filled Skutterudites with 4f

CeOs_{4}Sb_{12} (COS) and PrOs_{4}Sb_{12} (POS) are two representative compounds that provide the ideal vantage point to systematically study the physics of multi-f-electron systems. COS with Ce 4f^{1}, and POS with Pr 4f^{2} configurations show distinct properties of Kondo insulating and heavy fermion superconductivity, respectively. We unveiled the underlying microscopic origin by angle-resolved photoemission spectroscopy studies. Their eV-scale band structure matches well, representing the common characters of conduction electrons in ROs_{4}Sb_{12} systems (R=rare earth). However, f electrons interact differently with conduction electrons in COS and POS. Strong hybridization between conduction electrons and f electrons is observed in COS with band dependent hybridization gaps, and the development of a Kondo insulating state is directly revealed. Although the ground state of POS is a singlet, finite but incoherent hybridization exists, which can be explained by the Kondo scattering with the thermally excited triplet crystalline electric field state. Our results help us to understand the intriguing properties in COS and POS, and provide a clean demonstration of the microscopic differences in heavy fermion systems with 4f^{1} and 4f^{2} configurations.

[Hepatitis B virus antigen peptide presentation by Epstein-Barr virus-transformed peripheral blood B cells].

Objective: To establish an Epstein-Barr virus-transformed peripheral blood B cell line (BCL), and explore its phenotypic characteristics, the ability to secrete antibodies and cytokines, and the ability to present hepatitis B virus (HBV) antigen peptide. Methods: Peripheral blood mononuclear cells (PBMCs) were isolated from patients with HBV infection. Epstein-Barr virus supernatant was incubated to construct BCL. The expression of CD19, CD138, CD38, CD27 and the production levels of IFN - γ, IL-10, IL-6 were detected by flow cytometry. BCL loaded with HBV antigen peptide was incubated with in vitro-expanded autologous T cells. Intracellular staining was used to detect the level of interferon-gamma produced by T cells. Results: Compared with untransformed peripheral blood B cells, BCL had high expression levels of CD138, CD38 and CD27, and the difference was statistically significant (P < 0.05), while the level of IL-6 production was decreased, and the difference was statistically significant (P < 0.01). BCL loaded with HBV antigen peptide had significantly enhanced the production of interferon-gamma by in vitro-expanded autologous T cells, and the difference was statistically significant (P < 0.01). Conclusion: BCL highly expresses CD138, CD38 and CD27, but its ability to produce IL-6 decreases. BCL can improve the immune response efficiency of HBV-specific T cells to HBV antigen peptide, and serve as a new tool for hepatitis B immune research.

Evidence of cooperative effect on the enhanced superconducting transition temperature at the FeSe/SrTiO3 interface.

At the interface between monolayer FeSe films and SrTiO3 substrates the superconducting transition temperature (Tc) is unexpectedly high, triggering a surge of excitement. The mechanism for the Tc enhancement has been the central question, as it may present a new strategy for seeking out higher Tc materials. To reveal this enigmatic mechanism, by combining advances in high quality interface growth, 16O [Formula: see text] 18O isotope substitution, and extensive data from angle resolved photoemission spectroscopy, we provide striking evidence that the high Tc in FeSe/SrTiO3 is the cooperative effect of the intrinsic pairing mechanism in the FeSe and interactions between the FeSe electrons and SrTiO3 phonons. Furthermore, our results point to the promising prospect that similar cooperation between different Cooper pairing channels may be a general framework to understand and design high-temperature superconductors.

Unveiling the Superconducting Mechanism of Ba_{0.51}K_{0.49}BiO_{3}.

The mechanism of high superconducting transition temperatures (T_{c}) in bismuthates remains under debate despite more than 30 years of extensive research. Our angle-resolved photoemission spectroscopy studies on Ba_{0.51}K_{0.49}BiO_{3} reveal an unexpectedly 34% larger bandwidth than in conventional density functional theory calculations. This can be reproduced by calculations that fully account for long-range Coulomb interactions-the first direct demonstration of bandwidth expansion due to the Fock exchange term, a long-accepted and yet uncorroborated fundamental effect in many body physics.Furthermore, we observe an isotropic superconducting gap with 2Δ_{0}/k_{B}T_{c}=3.51±0.05, and strong electron-phonon interactions with a coupling constant λ∼1.3±0.2. These findings solve a long-standing mystery-Ba_{0.51}K_{0.49}BiO_{3} is an extraordinary Bardeen-Cooper-Schrieffer superconductor, where long-range Coulomb interactions expand the bandwidth, enhance electron-phonon coupling, and generate the high T_{c}. Such effects will also be critical for finding new superconductors.

Charge Transfer Effects in Naturally Occurring van der Waals Heterostructures (PbSe)_{1.16}(TiSe_{2})_{m} (m=1, 2).

van der Waals heterostructures (VDWHs) exhibit rich properties and thus has potential for applications, and charge transfer between different layers in a heterostructure often dominates its properties and device performance. It is thus critical to reveal and understand the charge transfer effects in VDWHs, for which electronic structure measurements have proven to be effective. Using angle-resolved photoemission spectroscopy, we studied the electronic structures of (PbSe)_{1.16}(TiSe_{2})_{m} (m=1, 2), which are naturally occurring VDWHs, and discovered several striking charge transfer effects. When the thickness of the TiSe_{2} layers is halved from m=2 to m=1, the amount of charge transferred increases unexpectedly by more than 250%. This is accompanied by a dramatic drop in the electron-phonon interaction strength far beyond the prediction by first-principles calculations and, consequently, superconductivity only exists in the m=2 compound with strong electron-phonon interaction, albeit with lower carrier density. Furthermore, we found that the amount of charge transferred in both compounds is nearly halved when warmed from below 10 K to room temperature, due to the different thermal expansion coefficients of the constituent layers of these misfit compounds. These unprecedentedly large charge transfer effects might widely exist in VDWHs composed of metal-semiconductor contacts; thus, our results provide important insights for further understanding and applications of VDWHs.

Band Dependent Interlayer f-Electron Hybridization in CeRhIn_{5}.

A key issue in heavy fermion research is how subtle changes in the hybridization between the 4f (5f) and conduction electrons can result in fundamentally different ground states. CeRhIn_{5} stands out as a particularly notable example: when replacing Rh with either Co or Ir, antiferromagnetism gives way to superconductivity. In this photoemission study of CeRhIn_{5}, we demonstrate that the use of resonant angle-resolved photoemission spectroscopy with polarized light allows us to extract detailed information on the 4f crystal field states and details on the 4f and conduction electron hybridization, which together determine the ground state. We directly observe weakly dispersive Kondo resonances of f electrons and identify two of the three Ce 4f_{5/2}^{1} crystal-electric-field levels and band-dependent hybridization, which signals that the hybridization occurs primarily between the Ce 4f states in the CeIn_{3} layer and two more three-dimensional bands composed of the Rh 4d and In 5p orbitals in the RhIn_{2} layer. Our results allow us to connect the properties observed at elevated temperatures with the unusual low-temperature properties of this enigmatic heavy fermion compound.

Cell transfer technique for constructing cytological microarrays for immunocytochemical analysis.

OBJECTIVE: To evaluate the utility of a proposed cell transfer technique for constructing cytological smear microarrays and its potential applications in multiplex immunocytochemical (ICC) staining. METHODS: Ninety-six cytology smears, including two pericardial effusions, 22 ascites and 72 pleural effusions, were transferred to a 33-plex cytological microarray. Paired staining of thyroid transcription factor-1 (TTF-1) and calretinin ICC was performed in duplicate slides. RESULTS: Most of the smeared cells selected for transfer could be removed from the original slides with a minimal loss of cells and with no change in morphological features or immunoreactivity. Comparison of the staining results with immunohistochemical staining results, clinical history and histopathological reports available for each patient revealed that TTF-1 was positive in 32/33 metastatic pulmonary adenocarcinomas (PACs), 1/15 non-pulmonary adenocarcinomas and 0/45 benign effusions. The ICC results for TTF-1 on a transferred cytological microarray revealed high (97%) sensitivity and high (96.7%) specificity for the detection of metastatic PAC. CONCLUSION: Cytology microarrays can be constructed by transferring cells from serous fluid cytological smears, and cells transferred to the microarray retain their morphological integrity and immunoreactivity. Researchers can use the technique for simultaneous immunostaining of multiple specimens in studies of neoplastic or non-neoplastic diseases when available tissue samples are limited.

Anomalous correlation effects and unique phase diagram of electron-doped FeSe revealed by photoemission spectroscopy.

FeSe layer-based superconductors exhibit exotic and distinctive properties. The undoped FeSe shows nematicity and superconductivity, while the heavily electron-doped KxFe2-ySe2 and single-layer FeSe/SrTiO3 possess high superconducting transition temperatures that pose theoretical challenges. However, a comprehensive study on the doping dependence of an FeSe layer-based superconductor is still lacking due to the lack of a clean means of doping control. Through angle-resolved photoemission spectroscopy studies on K-dosed thick FeSe films and FeSe0.93S0.07 bulk crystals, here we reveal the internal connections between these two types of FeSe-based superconductors, and obtain superconductivity below ∼ 46 K in an FeSe layer under electron doping without interfacial effects. Moreover, we discover an exotic phase diagram of FeSe with electron doping, including a nematic phase, a superconducting dome, a correlation-driven insulating phase and a metallic phase. Such an anomalous phase diagram unveils the remarkable complexity, and highlights the importance of correlations in FeSe layer-based superconductors.

Effects of Surface Electron Doping and Substrate on the Superconductivity of Epitaxial FeSe Films.

Superconductivity in FeSe is greatly enhanced in films grown on SrTiO3 substrates, although the mechanism behind remains unclear. Recently, surface potassium (K) doping has also proven able to enhance the superconductivity of FeSe. Here, by using scanning tunneling microscopy, we compare the K doping dependence of the superconductivity in FeSe films grown on two substrates: SrTiO3 (001) and graphitized SiC (0001). For thick films (20 unit cells (UC)), the optimized superconducting (SC) gaps are of similar size (∼9 meV) regardless of the substrate. However, when the thickness is reduced to a few UC, the optimized SC gap is increased up to ∼15 meV for films on SrTiO3, whereas it remains unchanged for films on SiC. This clearly indicates that the FeSe/SrTiO3 interface can further enhance the superconductivity, beyond merely doping electrons. Intriguingly, we found that this interface enhancement decays exponentially as the thickness increases, with a decay length of 2.4 UC, which is much shorter than the length scale for relaxation of the lattice strain, pointing to interfacial electron-phonon coupling as the likely origin.

Electronic structure of a new layered bismuth oxyselenide superconductor: LaO0.5F0.5BiSe2.

LaO(0.5)F(0.5)BiSe(2) is a new layered superconductor discovered recently, which shows the superconducting transition temperature of 3.5 K. With angle-resolved photoemission spectroscopy, we study the electronic structure of LaO(0.5)F(0.5)BiSe(2) comprehensively. Two electron-like bands are located around the X point of the Brillouin zone, and the outer pockets connect with each other and form large Fermi surface around Γ and M. These bands show negligible k(z) dispersion, indicating their two-dimensional nature. Based on the Luttinger theorem, the carrier concentration is about 0.53 e(-) per unit cell, close to its nominal value. Moreover, the photoemission data and the band structure calculations agree very well, and the renormalization factor is nearly 1.0, indicating the electron correlations in this material are rather weak. Our results suggest that LaO(0.5)F(0.5)BiSe(2) is a conventional BCS superconductor without strong electron correlations.

Tuning the band structure and superconductivity in single-layer FeSe by interface engineering.

The interface between transition metal compounds provides a rich playground for emergent phenomena. Recently, significantly enhanced superconductivity has been reported for single-layer FeSe on Nb-doped SrTiO3 substrate. Yet it remains mysterious how the interface affects the superconductivity. Here we use in situ angle-resolved photoemission spectroscopy to investigate various FeSe-based heterostructures grown by molecular beam epitaxy, and uncover that electronic correlations and superconducting gap-closing temperature (Tg) are tuned by interfacial effects. Tg up to 75 K is observed in extremely tensile-strained single-layer FeSe on Nb-doped BaTiO3, which sets a record high pairing temperature for both Fe-based superconductor and monolayer-thick films, providing a promising prospect on realizing more cost-effective superconducting device. Moreover, our results exclude the direct correlation between superconductivity and tensile strain or the energy of an interfacial phonon mode, and highlight the critical and non-trivial role of FeSe/oxide interface on the high Tg, which provides new clues for understanding its origin.

Micronucleus scoring in liver fine needle aspiration cytology.

OBJECTIVE: This study evaluated the role of the micronucleus (MN) in liver fine needle aspiration (FNA) cytology. METHODS: Histological features of 75 cases of hepatocellular carcinoma (HCC), of which 25 were well differentiated, 37 moderately differentiated and 13 poorly differentiated, and 58 benign hepatic lesions (total, 133 cases) were correlated with MN expression observed in FNA smears reported as benign (n =40), atypical (n = 14), suspicious (n = 30) and malignant (n =49). RESULTS: Stepwise increases in the MN score (0.4 ± 0.6, 1.2 ± 1.3, 6.3 ± 4.2 and 14.8 ± 8.8) correlated with the degree of cytological abnormality: benign, atypia, suspicious and malignant, respectively. The mean MN scores for well-, moderately and poorly differentiated HCC were 5.4 ± 2.2, 11.5 ± 4.5 and 24.9 ± 9.1, respectively, which was significantly different between malignant and suspicious (P < 0.0001), between suspicious and atypical (P= 0.008) but not between atypical and benign. The MN scores differed significantly between all degrees of differentiation of HCC and between the HCC and benign hepatic lesions (P < 0.0001). High sensitivity, specificity and accuracy of liver FNA for diagnosing HCC (96%, 98%, and 96%, respectively) were obtained at a cutoff of three for the MN score. CONCLUSIONS: The MN score is an effective HCC biomarker and has a good potential use as an ancillary tool for diagnosing HCC using FNA cytology.

Modelling and inference for epidemic models featuring non-linear infection pressure.

We consider a Susceptible-Infective-Removed (SIR) stochastic epidemic model in which the infection rate is of the form ßN⁻¹X(t)Y(t)(α). It is demonstrated that both the threshold behaviour of this model and the behaviour of the corresponding deterministic model differ markedly from the standard SIR model (i.e. α=1). Methods of statistical inference for this model are described, given outbreak data, and the extent to which all three model parameters can be estimated is considered.

Hyperglycaemic conditions decrease cultured keratinocyte mobility: implications for impaired wound healing in patients with diabetes.

BACKGROUND: Elevated blood glucose in patients with diabetes mellitus (DM) leads to complications including poor wound healing. Proper keratinocyte migration and proliferation are the crucial steps during re-epithelialization. We hypothesize that the impaired wound healing in patients with DM is due to the disruption of proper re-epithelialization. OBJECTIVES: We aimed to explore the effects of high glucose on keratinocytes in terms of cell migration and proliferation. METHODS: Keratinocytes were cultivated in normal and high glucose conditions. Their viability was evaluated by MTS assay. Transwell migration and in vitro scratch assays were used to evaluate their mobility. The mRNA expressions and activities of matrix metalloproteinase (MMP)-2 and MMP-9 were determined. The mRNA of their respective physiological inhibitors, tissue inhibitor of MMP (TIMP)-1 and TIMP-2, was also evaluated. Immunofluorescent staining and Western blotting were used to examine the expression of phosphorylated focal adhesion kinase (pp125(FAK)). The impacts of high glucose on keratinocyte proliferation were assessed by 5-bromo-2'-deoxyuridine incorporation assay. RESULTS: High glucose treatment did not affect keratinocyte viability up to 3 days. In contrast, the mobility of keratinocytes, the activities and gene expressions of MMP-2 and MMP-9, the expression of pp125(FAK), and the cell proliferation after 5 days were significantly downregulated after hyperglycaemic treatments while the mRNA expression of TIMP-1 increased. CONCLUSIONS: Under hyperglycaemic conditions, keratinocytes demonstrate reduced migration and decreased proliferation capacities. These impairments of keratinocyte functions are likely to result in inadequate re-epithelialization. These defective physiological events provide a reasonable explanation for the poor wound healing commonly observed in patients with DM.

Orthogonal subspace projection-based approaches to classification of MR image sequences.

Orthogonal subspace projection (OSP) approach has shown success in hyperspectral image classification. Recently, the feasibility of applying OSP to multispectral image classification was also demonstrated via SPOT (Satellite Pour 1'Observation de la Terra) and Landsat (Land Satellite) images. Since an MR (magnetic resonance) image sequence is also acquired by multiple spectral channels (bands), this paper presents a new application of OSP in MR image classification. The idea is to model an MR image pixel in the sequence as a linear mixture of substances (such as white matter, gray matter, cerebral spinal fluid) of interest from which each of these substances can be classified by a specific subspace projection operator followed by a desired matched filter. The experimental results show that OSP provides a promising alternative to existing MR image classification techniques.

Consulting with radiologists outside the hospital by using Java.

A Java-based teleradiology system that makes use of the Internet has been developed. Using this system, an on-call, off-duty radiologist can make diagnoses and perform consultations easily by reviewing the transferred images at home. The image accessibility of the system allows a hospital with such a system to assist an affiliated rural hospital without a full-time radiologist. The system consists of three components: the image server subsystem, the database server subsystem, and the client subsystem. All client subsystems of the system are designed to be symmetric. Users may retrieve images, manipulate them, and perform remote consultations. In addition, a user may add annotations to an image area of interest. Screen synchronization is achieved by means of the command-passing technique and local command execution to reduce the network bandwidth and transmission demands; user interaction is achieved by means of a synchronized indicator for pointing out areas of interest and dialog windows for conversation. Because Java programs can run on heterogeneous platforms, the need for system maintenance and user training is minimized. Although the drawback of Internet bandwidth still exists, the system enables platform-independent teleradiology via the Internet and allows easy and cost-effective remote consultation.