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Topological phases of matter offer exciting possibilities to realize lossless charge and spin information transport on ultrafast time scales. However, this requires detailed knowledge of their nonequilibrium properties. Here, we employ time-, spin- and angle-resolved photoemission to investigate the ultrafast response of the Sb(111) spin-polarized surface state to femtosecond-laser excitation. The surface state exhibits a giant mass enhancement which is observed as a kink structure in its energy-momentum dispersion above the Fermi level. The kink structure, originating from the direct coupling of the surface state to the bulk continuum, is characterized by an abrupt change in the group velocity by ~70%, in agreement with our GW-based band structure calculations. Our observation of this connectivity in the transiently occupied band structure enables the unambiguous experimental verification of the topological nature of the surface state. The influence of bulk-surface coupling is further confirmed by our measurements of the electron dynamics, which show that bulk and surface states behave as a single thermalizing electronic population with distinct contributions from low-k electron-electron and high-k electron-phonon scatterings. These findings are important for future applications of topological semimetals and their excitations in ultrafast spintronics. Understanding the coupling between spin-polarised topological surface states and the bulk provides insight into ultrafast spin dynamics. Here, this coupling is shown to be accompanied by a large mass enhancement in the Sb(111) surface electronic structure, leading to unusual dynamics.

Most traditional semiconductor materials are based on the control of doping densities to create junctions and thereby functional and efficient electronic and optoelectronic devices. The technology development for halide perovskites had initially only rarely made use of the concept of electronic doping of the perovskite layer and instead employed a variety of different contact materials to create functionality. Only recently, intentional, or unintentional doping of the perovskite layer is more frequently invoked as an important factor explaining differences in photovoltaic or optoelectronic performance in certain devices. Here we use numerical simulations to study the influence of doping and photodoping on photoluminescence quantum yield as well as other device relevant metrics. We find that doping can improve the photoluminescence quantum yield by making radiative recombination faster. This effect can benefit or harm photovoltaic performance given that the improvement of photoluminescence quantum efficiency and open-circuit voltage is accompanied by a reduction of the diffusion length. This reduction will eventually lead to inefficient carrier collection at high doping densities. The photovoltaic performance might improve at an optimum doping density which depends on a range of factors such as the mobilities of the different layers and the ratio of the capture cross sections for electrons and holes., 27 Pages, 9 Figures, supporting information inclused

The formation of large polarons has been proposed as reason for the high defect tolerance, low mobility, low charge carrier trapping and low nonradiative recombination rates of lead halide perovskites. Recently, direct evidence for large-polaron formation has been reported from a 50% effective mass enhancement in angle-resolved photoemission of CsPbBr3 over theory for the orthorhombic structure. We present in-depth band dispersion measurements of CsPbBr3 and GW calculations which lead to almost identical effective masses at the valence band maximum of 0.203+/-0.016 m0 in experiment and 0.226 m0 in orthorhombic theory. We argue that the effective mass can be explained solely on the basis of electron-electron correlation and large-polaron formation cannot be concluded from photoemission data., Comment: Version 2 contains more precise theoretical values and supplemental material

Physical review / B 104(24), 245105 (2021). doi:10.1103/PhysRevB.104.245105, In this work, we studied the bulk band structure of a topological insulator (TI) Bi$_2$Se$_3$ and determinedthe contributions of the Bi and Se orbital states to the valence bands using standing-wave excited hard x-rayphotoemission spectroscopy (SW-HAXPES). This SW technique can provide the element-resolved informationand extract individual Bi and Se contributions to the Bi$_2$Se$_3$ valence band. Comparisons with density-functionaltheory calculations (local density approximation and GW) reveal that the Bi 6s, Bi 6p, and Se 4p states aredominant in the Bi$_2$Se$_3$ HAXPES valence band. These findings pave a way for studying the element-resolvedband structure and orbital contributions of this class of TIs., Published by Inst., Woodbury, NY

Emerging evidence indicates that adipose stromal cells (ASC) are recruited to enhance cancer development. In this study, we examined the role these adipocyte progenitors play relating to intercellular communication in obesity-associated endometrial cancer. This is particularly relevant given that gap junctions have been implicated in tumor suppression. Examining the effects of ASCs on the transcriptome of endometrial epithelial cells (EEC) in an in vitro coculture system revealed transcriptional repression of GJA1 (encoding the gap junction protein Cx43) and other genes related to intercellular communication. This repression was recapitulated in an obesity mouse model of endometrial cancer. Furthermore, inhibition of plasminogen activator inhibitor 1 (PAI-1), which was the most abundant ASC adipokine, led to reversal of cellular distribution associated with the GJA1 repression profile, suggesting that PAI-1 may mediate actions of ASC on transcriptional regulation in EEC. In an endometrial cancer cohort (n = 141), DNA hypermethylation of GJA1 and related loci TJP2 and PRKCA was observed in primary endometrial endometrioid tumors and was associated with obesity. Pharmacologic reversal of DNA methylation enhanced gap-junction intercellular communication and cell–cell interactions in vitro. Restoring Cx43 expression in endometrial cancer cells reduced cellular migration; conversely, depletion of Cx43 increased cell migration in immortalized normal EEC. Our data suggest that persistent repression by ASC adipokines leads to promoter hypermethylation of GJA1 and related genes in the endometrium, triggering long-term silencing of these loci in endometrial tumors of obese patients. Significance: Studies reveal that adipose-derived stem cells in endometrial cancer pathogenesis influence epigenetic repression of gap junction loci, which suggests targeting of gap junction activity as a preventive strategy for obesity-associated endometrial cancer.

Quantum well states formed by d electrons in metallic thin films are responsible for many fundamental phenomena that oscillate with layer thickness, such as magnetic anisotropy or magnetoresistance. Using momentum microscopy and angle-resolved photoemission, we mapped in unprecedented detail the quantized electronic states of Fe(001) in a broad photon energy range starting from soft x-ray (160 eV) down to vacuum ultraviolet (8.4 eV). We show that it is possible to simulate the experimentally observed photoemission spectra with high accuracy by using the ab initio electronic bulk band structure as the initial state, taking into account that free electron final electronic states are intrinsically broadened along the wave vector direction perpendicular to the sample surface. To simulate the thin-film case, we take into account a subset of the initial electronic states, which results in the reproduction of the quantized electronic structure observed in the experiment. In addition, we present results of the spin-sensitive measurements, which are confronted with the photoemission simulation that takes into account the spin degree of freedom. We demonstrate electronic states that can be responsible for the oscillations of the magnetic anisotropy in Fe(001) thin films with periods of about 5 and 9 monolayers. We show that these quantum well states change position in reciprocal space depending on the magnetization direction. Our photoemission simulation reproduces this effect, which highlights its origin in the relativistic bulk electronic band structure of bcc Fe. We also observed magnetization-dependent spin-orbit gaps with the symmetry lower than the bulk symmetry. We believe that the same method of simulating photoemission spectra might facilitate interpretation of the photoemission intensities measured for other three-dimensional materials, especially when the spin-polarized quantized electronic states are considered.

While first-principles calculations with different levels of sophistication predict a topologically trivial ${\mathbb{Z}}_{2}$ state for bulk bismuth, some photoemission experiments show surface states consistent with the interpretation of bismuth being in a topologically nontrivial ${\mathbb{Z}}_{2}$ state. We resolve this contradiction between theory and experiment by showing, based on quasiparticle self-consistent $GW$ calculations, that the experimental surface states interpreted as supporting a nontrivial phase are actually consistent with a trivial ${\mathbb{Z}}_{2}$ invariant. We identify this contradiction as the result of a crosstalk effect arising from the extreme penetration depth of the surface states into the bulk of Bi. A film of Bi can be considered bulklike only for thicknesses of about 1000 bilayers ($\ensuremath{\approx}400$ nm) and more.

Materials advances (2021). doi:10.1039/D0MA00902D, Published by Royal Society of Chemistry, Cambridge

Slow nonradiative recombination is a key factor in achieving high open-circuit voltages or high luminescence yields in any optoelectronic material. Whether a defect is contributing substantially to nonradiative recombination is often estimated by defect statistics based on the model by Shockley, Read, and Hall. However, defect statistics are agnostic to the origin of the capture coefficients and therefore conclude that essentially every defect between the two quasi-Fermi levels is equally likely to be a recombination-active defect. Here, we combine Shockley-Read-Hall statistics with microscopic models for defect-assisted recombination to study how the microscopic properties of a material affect how recombination active a defect is depending on its energy level. We then use material parameters representative of typical photovoltaic absorber materials ($\mathrm{C}{\mathrm{H}}_{3}\mathrm{N}{\mathrm{H}}_{3}\mathrm{Pb}{\mathrm{I}}_{3}$, Si, and GaAs) to illustrate the relevance, but also the limitations of our model.

We show that, although the equilibrium band dispersion of the Shockley-type surface state of two-dimensional Au(111) quantum films grown on W(110) does not deviate from the expected free-electron-like behavior, its nonequilibrium energy-momentum dispersion probed by time- and angle-resolved photoemission exhibits a remarkable kink above the Fermi level due to a significant enhancement of the effective mass. The kink is pronounced for certain thicknesses of the Au quantum well and vanishes in the very thin limit. We identify the kink as induced by the coupling between the Au(111) surface state and emergent quantum-well states which probe directly the buried gold-tungsten interface. The signatures of the coupling are further revealed by our time-resolved measurements which show that surface state and quantum-well states thermalize together behaving as dynamically locked electron populations. In particular, relaxation of hot carriers following laser excitation is similar for both surface state and quantum-well states and much slower than expected for a bulk metallic system. The influence of quantum confinement on the interplay between elementary scattering processes of the electrons at the surface and ultrafast carrier transport in the direction perpendicular to the surface is shown to be the reason for the slow electron dynamics. Nanyang Technological University Published version Financial support from the Impuls-und Vernetzungsfonds der Helmholtz-Gemeinschaft under Grant No. HRSF-0067 (Helmholtz-Russia Joint Research Group) is gratefully acknowledged. M.B. gratefully acknowledges financial support from the Nanyang Technological University, NAP-SUG.

Endometrial cancer is the most common gynecological cancer in the United States. We wanted to identify epigenetic aberrations involving microRNAs (miRNAs), whose genes become hypermethylated in endometrial primary tumors. By integrating known miRNA sequences from the miRNA database (miRBase) with DNA methylation data from methyl-CpG-capture sequencing, we identified 111 differentially methylated regions (DMRs) associated with CpG islands (CGIs) and miRNAs. Among them, 22 DMRs related to 29 miRNAs and within 8 kb of CGIs were hypermethylated in endometrial tumors but not in normal endometrium. miR-137 was further validated in additional endometrial primary tumors. Hypermethylation of miR-137 was found in both endometrioid and serous endometrial cancer (P

Obesity increases cancer risk including breast cancer (BC). However, the direct regulatory mechanisms by which obesity promotes BC progression remain largely unknown. We show that lysophosphatidic acid/protein kinase D1 (LPA/PKD-1)-CD36 signaling is a bona fide breast cancer promoter via stimulating microvascular remodeling in chronic diet-induced obesity (DIO). We observed that the growth of an estrogen receptor (ER) positive breast cancer was markedly increased when compared to the lean control, and specifically accompanied by increased microvascular remodeling in a syngeneic BC model in female DIO mice. The tumor neovessels in DIO mice demonstrated elevated levels of alpha smooth muscle actin (α-SMA), vascular endothelial growth factor receptor 2 (VEGFR 2) and endothelial differentiation gene 2/LPA receptor1 (Edg2/LPA1), enhanced PKD-1 phosphorylation, and reduced CD36 expression. Tumor associated endothelial cells (TAECs) exposed to LPA demonstrated sustained nuclear PKD-1 phosphorylation, and elevated mRNA levels of ephrin B2, and reduced mRNA expression of CD36. TAEC proliferation also increased in response to LPA/PKD-1 signaling. These studies suggest that the LPA/PKD-1-CD36 signaling axis links DIO to malignant progression of BC via stimulation of de novo tumor arteriogenesis through arteriolar remodeling of microvasculature in the tumor microenvironment. Targeting this signaling axis could provide an additional novel therapeutic strategy.

The authors investigate the electronic and spin structure of topological surface states across a topological quantum phase transition. They find a surface band gap opening at the Dirac point of the topological surface states, giving rise to massive fermions with nonzero spin polarization on both sides of the phase transition. A mechanism of bulk-mediated scattering processes that increase with decreasing spin-orbit coupling strength is proposed as an explanation for the problem of the unconventional transformation between spin Dirac phases.

Emerging evidence indicates that adipose stromal cells (ASC) are recruited to enhance cancer development. In this study, we examined the role these adipocyte progenitors play relating to intercellular communication in obesity-associated endometrial cancer. This is particularly relevant given that gap junctions have been implicated in tumor suppression. Examining the effects of ASCs on the transcriptome of endometrial epithelial cells (EEC) in an in vitro co-culture system revealed transcriptional repression of GJA1 (encoding the gap junction protein Cx43) and other genes related to intercellular communication. This repression was recapitulated in an obesity mouse model of endometrial cancer. Furthermore, inhibition of plasminogen activator inhibitor 1 (PAI-1), which was the most abundant ASC adipokine, led to reversal of cellular distribution associated with the GJA1 repression profile, suggesting that PAI-1 may mediate actions of ASC on transcriptional regulation in EEC. In an endometrial cancer cohort (n=141), DNA hypermethylation of GJA1 and related loci TJP2 and PRKCA was observed in primary endometrial endometrioid tumors and was associated with obesity. Pharmacologic reversal of DNA methylation enhanced gap junction intercellular communication and cell-cell interactions in vitro. Restoring Cx43 expression in endometrial cancer cells reduced cellular migration; conversely, depletion of Cx43 increased cell migration in immortalized normal EEC. Our data suggest that persistent repression by ASC adipokines leads to promoter hypermethylation of GJA1 and related genes in the endometrium, triggering long-term silencing of these loci in endometrial tumors of obese patients.

Polymorphous sweat gland carcinoma is an uncommon low-grade malignant adnexal tumor with a marked predilection for the distal extremities. Histologically, the lesions are characterized by a cellular proliferation showing a combination of growth patterns, including trabecular, solid, tubular, cribriform, or adenoid cystic and pseudopapillary. The immunohistochemical and molecular profile of these tumors has not yet been properly addressed. We have studied 3 cases of polymorphous sweat gland carcinoma using a broad panel of immunohistochemical markers including cytokeratin AE1/AE3, CK5/6, MOC31, p40, p63, p16, chromogranin, synaptophysin, CD56, MIB-1, estrogen receptor, progesterone receptor, androgen receptor, BER-EP4, smooth muscle actin, epithelial membrane antigen, carcinoembryonic antigen, CD117, S100 protein, HBME-1, DOG1, vimentin, and mammaglobin. We also examined for the MYB-NFIB fusion by fluorescent in situ hybridization (ISH) and for human papilloma virus by ISH. Our studies show that cytokeratin AE1/AE3, CK5/6, p40, p63, p16, chromogranin, and CD56 stains were positive in all 3 cases. All 3 cases were negative for MYB-NFIB fusion by fluorescent ISH which rules out adenoid cystic carcinoma. DNA ISH studies for high-risk human papilloma virus were negative in all cases. MIB-1 proliferation index was very high (30%-70% nuclear positivity), supporting a malignant phenotype. The positivity for chromogranin and CD56 suggests partial neuroendocrine differentiation. The differential diagnosis includes metastases from internal malignancies, basal cell carcinoma, and other benign and malignant adnexal neoplasms such as adenoid cystic carcinoma, ductal eccrine carcinoma, and microcystic carcinoma. Positivity for p16 in combination with chromogranin and CD56 may be potentially good markers for differentiating this tumor from other adnexal tumors.

Intrinsic or acquired chemoresistance is a hurdle in oncology. Only 7%-16% of estrogen receptor α (ERα) positive breast cancer cases achieve a pathological complete response (pCR) after neo-adjuvant chemotherapy. Nogo-B receptor (NgBR) is a cell surface receptor that binds farnesylated Ras and promotes Ras translocation to the plasma membrane. Here, we demonstrate NgBR as a potential therapeutic target for ERα positive breast cancer patients to attenuate paclitaxel resistance. NgBR knockdown enhanced paclitaxel-induced cell apoptosis by modulating expression of p53 and survivin in ERα positive breast cancer cells via NgBR-mediated PI3K/Akt and MAPK/ERK signaling pathways. NgBR knockdown attenuated either 17β-estradiol or epidermal growth factor stimulated phosphorylation of ERα at Serine 118 residue. The ChIP-PCR assay further demonstrated that NgBR knockdown decreased ERα binding to the estrogen response element (ERE) of the ERα target gene and increased the binding of p53 to the promoter region of survivin to attenuate survivin transcription. In summary, our data suggest that NgBR expression is essential to promoting ERα positive breast cancer cell resistance to paclitaxel. Findings from this study implicate a novel therapeutic target for treating ERα positive breast cancer in neo-adjuvant/adjuvant chemotherapy.

We report on the systematic study of infrared/terahertz spectra of photocurrents in (Bi, Sb) Te based three-dimensional topological insulators. We demonstrate that in a wide range of frequencies, ranging from fractions up to tens of terahertz, the photocurrent is caused by the linear photogalvanic effect (LPGE) excited in the surface states. The photocurrent spectra reveal that at low frequencies the LPGE emerges due to free carrier Drude-like absorption. The spectra allow us to determine the room temperature carrier mobilities in the surface states despite the presence of thermally activated residual impurities in the material bulk. In a number of samples we observed an enhancement of the linear photogalvanic effect at frequencies between 30 and 60 THz, which is attributed to the excitation of electrons from helical surface to bulk conduction band states. Under this condition and applying oblique incidence we also observed the circular photogalvanic effect driven by the radiation helicity.

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Quantum-phase transitions between trivial insulators and topological insulators differ from ordinary metal-insulator transitions in that they arise from the inversion of the bulk band structure due to strong spin–orbit coupling. Such topological phase transitions are unique in nature as they lead to the emergence of topological surface states which are characterized by a peculiar spin texture that is believed to play a central role in the generation and manipulation of dissipationless surface spin currents on ultrafast timescales. Here, we provide a generalized G W +Boltzmann approach for the description of ultrafast dynamics in topological insulators driven by electron–electron and electron–phonon scatterings. Taking the prototypical insulator Bi 2 Te 3 as an example, we test the robustness of our approach by comparing the theoretical prediction to results of time- and angle-resolved photoemission experiments. From this comparison, we are able to demonstrate the crucial role of the excited spin texture in the subpicosecond relaxation of transient electrons, as well as to accurately obtain the magnitude and strength of electron–electron and electron–phonon couplings. Our approach could be used as a generalized theory for three-dimensional topological insulators in the bulk-conducting transport regime, paving the way for the realization of a unified theory of ultrafast dynamics in topological materials.

Background: Obesity increases breast cancer (BC) risk. However, the molecular links by which obesity promotes BC progression remain largely unknown. Lysophosphatidic acid (LPA) produced excessively in obesity is a lipid signaling mediator essential for vascular remodeling, angiogenesis and BC progression, in which protein kinase D1 (PKD-1) and angiogenic regulator CD36 play an important role. Hypothesis: Obesity promotes microvascular remodeling and angiogenesis for BC progression via LPA/PKD-1-CD36 signaling axis. Methods: The hypothesis was tested in tumor-associated endothelial cells (TAECs), BC cells and a diet-induced obesity (DIO) mouse model. Lentiviral transduction, qPCR, Western blotting and Halo pull-down assays, angiogenesis profiling and immunofluorescence and immunohistochemical assays were applied for analysis of gene and protein expression, and relevant signaling pathways. Seahorse Bioscience Extracellular Flux Analyzer was used to detect cellular mitochondrial respiration. Results: LPA/PKD-1-CD36 signaling was a bona fide BC promoter via stimulating microvascular remodeling in chronic DIO. ER + breast cancer grew faster and larger in the DIO mice than in the lean control, specifically accompanied by enhanced microvascular remodeling in a syngeneic ER + BC model. The expression of vascular endothelial cell growth receptor 2, and endothelial differentiation gene 2/LPA receptor 1 (Edg2/LPA 1 ), and phospho-PKD-1 also increased, accompanied by CD36 downregulation in the tumor endothelium. TAECs exposed to LPA showed sustained nuclear PKD-1 phosphorylation, and elevated mRNA levels of ephrin B2, and reduced CD36 mRNA expression, along with increased proliferation, which was inhibited by a selective PKD inhibitor. Finally, LPA/PKD-1 signaling changed mitochondrial respiration in ECs and breast adenocarcinoma cells. Conclusion: These studies suggest that LPA/PKD-1-CD36 signaling axis links DIO to BC progression via stimulation of arteriolar remodeling of microvasculature in the tumor microenvironment. The axis-mediated changes in cellular metabolism may promote the microvascular remodeling process. Targeting this signaling axis could provide an additional novel therapeutic strategy against breast cancer.

ReS2 is considered as a promising candidate for novel electronic and sensor applications. The low crystal symmetry of this van der Waals compound leads to a highly anisotropic optical, vibrational, and transport behavior. However, the details of the electronic band structure of this fascinating material are still largely unexplored. We present a momentum-resolved study of the electronic structure of monolayer, bilayer, and bulk ReS2 using k-space photoemission microscopy in combination with first-principles calculations. We demonstrate that the valence electrons in bulk ReS2 are—contrary to assumptions in recent literature—significantly delocalized across the van der Waals gap. Furthermore, we directly observe the evolution of the valence band dispersion as a function of the number of layers, revealing the transition from an indirect band gap in bulk ReS2 to a direct gap in the bilayer and the monolayer. We also find a significantly increased effective hole mass in single-layer crystals. Our results establish bilayer ReS2 as an advantageous building block for two-dimensional devices and van der Waals heterostructures.

Scope The chemopreventive effects of black raspberries (BRBs) have not been studied in endometrial tumorigenesis. Here, they are examined in a mouse model of endometrial cancer. Methods and results Wild-type and Pten heterozygous (+/-) female mice are weaned at 3 weeks and fed with four AIN-93G diets: 93G; 93G+5% BRBs powder; high-fat (HF); and HF+5% BRBs. Body weight and diet consumption are recorded weekly until the mice are euthanized at 28 weeks of age. Mice fed with HF diets are found to significantly gain body weight over time. BRBs are not found to affect the development of obesity. Mice in the HF+BRBs group consume less food than the HF-only mice. HF+BRBs diets suppress uterine tumor initiation and promotion more than the HF-only diet by inhibiting cell proliferation. It also reduces HF-induced levels of plasma leptin and 17β-estradiol (E2). Urolithin A, a metabolite of BRBs, suppresses cell proliferation induced by leptin and E2. Conclusion BRBs are preventive in HF-mediated uterine tumorigenesis because they suppress cell growth and plasma leptin and E2 levels.

The management of endocervical adenocarcinoma is largely based on tumor size and depth of invasion (DOI); however, DOI is difficult to measure accurately. The surgical treatment includes resection of regional lymph nodes, even though most lymph nodes are negative and lymphadenectomies can cause significant morbidity. We have investigated alternative parameters to better identify patients at risk of node metastases. Cases of invasive endocervical adenocarcinoma from 12 institutions were reviewed, and clinical/pathologic features assessed: patients' age, tumor size, DOI, differentiation, lymph-vascular invasion, lymph node metastases, recurrences, and stage. Cases were classified according to a new pattern-based system into Pattern A (well-demarcated glands), B (early destructive stromal invasion arising from well-demarcated glands), and C (diffuse destructive invasion). In total, 352 cases (FIGO Stages I-IV) were identified. Patients' age ranged from 20 to 83 years (mean 45), DOI ranged from 0.2 to 27 mm (mean 6.73), and lymph-vascular invasion was present in 141 cases. Forty-nine (13.9%) demonstrated lymph node metastases. Using this new system, 73 patients (20.7%) with Pattern A tumors (all Stage I) were identified. None had lymph node metastases and/or recurrences. Ninety patients (25.6%) had Pattern B tumors, of which 4 (4.4%) had positive nodes; whereas 189 (53.7%) had Pattern C tumors, of which 45 (23.8%) had metastatic nodes. The proposed classification system can spare 20.7% of patients (Pattern A) of unnecessary lymphadenectomy. Patients with Pattern B rarely present with positive nodes. An aggressive approach is justified in patients with Pattern C. This classification system is simple, easy to apply, and clinically significant.

cope Obese and overweight women are at high risk of developing endometrial cancer; indeed, many of endometrial cancer patients are obese. The increased number and size of adipocytes due to obesity elevate levels of circulating estrogens that stimulate cell proliferation in the endometrium. However, black raspberries are a promising approach to preventing endometrial cancer. Methods and results We examined 17 black raspberry constituents and metabolites (10 μM or 10 μg/mL, 48 h) for their ability to prevent endometrial cancer cells from proliferating. Urolithin A (UA) was most able to suppress proliferation in a time- and dose-dependent manner (p < 0.05). It arrested the G2/M phase of the cell cycle by upregulating cyclin-B1, cyclin-E2, p21, phospho-cdc2, and CDC25B. UA also acted as an estrogen agonist by modulating estrogen receptor-α (ERα) dependent gene expression in ER-positive endometrial cancer cells. UA enhanced the expression of ERβ, PGR, pS2, GREB1 while inhibiting the expression of ERα and GRIP1. Coincubating UA-treated cells with the estrogen antagonist ICI182,780 abolished UA's estrogenic effects. Knocking down ERα suppressed PGR, pS2, and GREB gene expression but increased GRIP1 expression. Thus, UA's actions appear to be mediated through ERα. Conclusion This study suggests that UA modulates ERα-dependent gene expression, thereby inhibiting endometrial cancer proliferation.

We perform ultrahigh-resolution angle-resolved photoemission experiments at a temperature $T=0.8$ K on the type-II Weyl semimetal candidate ${\mathrm{WTe}}_{2}$. We find a surface Fermi arc connecting the bulk electron and hole pockets on the (001) surface. Our results show that the surface Fermi arc connectivity to the bulk bands is strongly mediated by distinct surface resonances dispersing near the border of the surface-projected bulk band gap. By comparing the experimental results to first-principles calculations, we argue that the coupling to these surface resonances, which are topologically trivial, is compatible with the classification of ${\mathrm{WTe}}_{2}$ as a type-II Weyl semimetal hosting topological Fermi arcs. We further support our conclusion by a systematic characterization of the bulk and surface character of the different bands and discuss the similarity of our findings to the case of topological insulators.

The potential of vanadium substituted In2S3 as the active material in intermediate band solar cells (IBSCs) is investigated. The study is performed with a detailed balance model developed by Cuadra et al. that takes into account the shape and overlap of the absorption coefficients. Despite having values of the band gaps that could in principle lead to highly efficient IBSCs, it is found that cells with a practical thickness made of V2In14S24 have a lower efficiency limit than conventional single band gap solar cell materials. It has previously been explained why overlapping absorption coefficients requires the cell thickness to be optimized. In this work it is shown that the thickness dependency of the cell efficiency can have two peaks. In this particular case the two peaks occur at cell thicknesses around 1 μ m and 1 m. The reason for this double peaked dependency is processes where photons are emitted over one band gap and reabsorbed over another. Some of these processes can happen at very low rates and thus not give a significant contribution before a very thick cell is considered. For cells with a reasonable thickness, maximum efficiencies of 20.8% and 26.4% are found for light intensities corresponding to 1 and 1000 suns.

We present absorption properties enhancement for two CuGaS2-based intermediate-band materials, as promising compounds for high efficiency, lower-cost photovoltaic devices. Previous band diagrams calculations predicted that these materials present a partially filled localized band within the band gap of the host semiconductor, which would increase the absorption of low-energy photons, creating additional electron–hole pairs respect to a conventional semiconductor. This could ideally result in an increase of the photocurrent of the cell without the fall of the open-circuit voltage. In this paper we show, using density functional methods, the effect of this intermediate band on the optical properties of the derived alloys. We highlight the significant enhancement of the absorption coefficient observed in the most intense range of the solar emission and we study the reflectance and transmittance properties of the materials in order to understand the effect of the thickness of the sample on the optical properties. We compare two different substituents of the Ga atoms in CuGaS2, namely, Ti and Cr atoms, able to form the intermediate-band material, and their interest for photovoltaic applications.

ZnO doped with some transitions metals (ZnO:M) has several significant potential application. ZnO:Co is proposed to be used in advanced spintronic devices due to its high Curie temperature and large magnetic moments per transition metal. ZnO:Cd has potential applications in short-wavelength optoelectronic devices. This work focuses on an ab-initio study of the electronic and optical properties of ZnO:M doped with Co, and Cd. Theoretical calculations have been done with different computational codes, using the density functional theory (DFT) at the GGA and GGA+U level. The latter introduces a Hubbard term correction in the “d” levels of the Zn and Co. We used different supercells in order to have different realistic dilution levels which can be achieved in experiments. Doping effects on the features of the optical absorption are also studied and analysed in this work.

e12662Background: Androgen receptor (AR) expression has recently emerged as a potential prognostic and predictive marker in patients with triple negative breast cancer (TNBC). We conducted a retros...

e12663Background: Obesity has been suggested as a risk factor for development of triple negative breast cancer (TNBC) in a meta-analysis. However, the impact of obesity on TNBC outcomes is still un...

In this work, we present frozen phonon and linear response ab-initio research into the vibrational properties of the CuGaS2 chalcopyrite and transition metal substituted (CuGaS2)M alloys. These systems are potential candidates for developing a novel solar-cell material with enhanced optoelectronic properties based in the implementation of the intermediate-band concept. We have previously carried out ab-initio calculations of the electronic properties of these kinds of chalcopyrite metal alloys showing a narrow transition metal band isolated in the semiconductor band gap. The substitutes used in the present work are the 3d metal elements, Titanium and Chromium. For the theoretical calculations we use standard density functional theory at local density and generalized gradient approximation levels. We found that the optical phonon branches of the transition metal chalcopyrite, are very sensitive to the specific bonding geometry and small changes in the transition metal environment.

Background: Obesity increases breast cancer (BC) risk but mechanisms by which obesity promotes BC progression remain largely unknown. Nutritional obesity is accompanied by increasing phospholipid lysophosphatidic acid (LPA), which stimulates angiogenesis by turning off CD36 antiangiogenic switch in microvascular endothelial cells (MVECs) via protein kinase D (PKD-1) signaling pathway that was reported to regulate mitochondrial function. CD36 impacts cellular energy metabolism as it is known to function as a fatty acid transporter. Hypothesis Obesity-derived LPA promotes angiogenesis and BC progression by modifying mitochondrial bioenergetics in cancer and endothelial cells via PKD-1 signaling. Methods: MVECs and breast adenocarcinoma cells were used for elucidating key signaling pathway and detecting mitochondrial respiration. BC angiogenesis model was established in diet-induced obese and lean mice. Results: LPA enhanced mitochondrial respiration in breast adenocarcinoma cells transduced with PKD-1, leading to elevations in oxygen consumption rate (OCR) and ATP-linked OCR, but not in extracellular acidification rate (ECAR). The cancer cells exposed to conditional medium from MVECs transduced with PKD-1 showed reduced level of basal OCR, ATP-linked OCR, and ECAR. Tumor-associated ECs exposed to LPA decreased CD36 expression whereas LPA exposure reduced not only basal OCR and ATP-linked mitochondrial respiration but also basal ECAR. Overexpressing PKD-1 also reduced basal OCR and ATP-linked mitochondrial respiration in these cells. In syngeneic breast adenocarcinoma model, BC grew larger in diet induced obese mice when compared with that in lean controls (p < 0.01). The tumor endothelium in diet-induced obese mice showed increased LPA receptor 1 expression, along with reduced CD36 expression and enhanced PKD-1 phosphorylation. Concurrently, the quantity of periphery vessels was increased, with elevations in plasma level of angiogenic proteins leptin and PAI 1. Conclusion: LPA/PKD-CD36 signaling may regulate angiogenesis and promote BC progression by controlling mitochondrial respiration via modulating cellular bioenergetics. Targeting LPA/PKD-CD36-metabolic signaling axis might provide a novel therapeutic strategy.

Time reversal dictates that nonmagnetic, centrosymmetric crystals cannot be spin-polarized as a whole. However, it has been recently shown that the electronic structure in these crystals can in fact show regions of high spin-polarization, as long as it is probed locally in real and in reciprocal space. In this article we present the first observation of this type of compensated polarization in MoS$_2$ bulk crystals. Using spin- and angle-resolved photoemission spectroscopy (ARPES) we directly observed a spin-polarization of more than 65% for distinct valleys in the electronic band structure. By additionally evaluating the probing depth of our method we find that these valence band states at the $\overline{\text{K}}$ point in the Brillouin zone are close to fully polarized for the individual atomic trilayers of MoS$_2$, which is confirmed by our density functional theory calculations. Furthermore, we show that this spin-layer locking leads to the observation of highly spin-polarized bands in ARPES since these states are almost completely confined within two dimensions. Our findings prove that these highly desired properties of MoS$_2$ can be accessed without thinning it down to the monolayer limit.

Under the terms of the Creative Commons Attribution License 3.0 (CC-BY).-- et al., We report first-principles GW results on the dispersion of the bulk band-gap edges in the three-dimensional topological insulator Sb2Te3. We find that, independently of the reference density-functional-theory band structure and the crystal-lattice parameters used, the one-shot GW corrections enlarge the fundamental band gap, bringing its value in close agreement with experiment. We conclude that the GW corrections cause the displacement of the valence-band maximum (VBM) to the Γ point, ensuring that the surface-state Dirac point lies above the VBM. We extend our study to the analysis of the electron-energy-loss spectrum (EELS) of bulk Sb2Te3. In particular, we perform energy-filtered transmission electron microscopy and reflection EELS measurements. We show that the random-phase approximation with the GW quasiparticle energies and taking into account virtual excitations from the semicore states leads to good agreement with our experimental data., We acknowledge funding from the University of Basque Country UPV/EHU (IT-756-13), the Departamento de Educacion del Gobierno Vasco, the Tomsk State University Competitiveness Improvement Program, the Spanish Ministry of Economy and Competitiveness MINECO (Grant No. FIS2013-48286-C2-1-P), the Science Development Foundation under the President of the Republic of Azerbaijan [Grant No. EIF-2011-1(3)-82/69/4-M-50], and Saint Petersburg State University (Project No. 11.50.202.2015). The energy-filtered TEM experiment was performed at Beyond-Nano (PON a3-00363). The EELS experiment was performed at UNIMORE, and acknowledges partial support from PRIN GRAF 20105ZZTSE-008. The work was also supported by the Alexander von Humboldt Foundation through a postdoctoral fellowship, and by the Helmholtz Association through the Virtual Institute for Topological Insulators (VITI).

The bulk band structure of Bi$_2$Te$_3$ has been determined by angle-resolved photoemission spectroscopy and compared to first-principles calculations. We have performed calculations using the local density approximation (LDA) of density functional theory and the one-shot $GW$ approximation within the all-electron full-potential linearized augmented-plane-wave (FLAPW) formalism, fully taking into account spin-orbit coupling. Quasiparticle effects produce significant changes in the band structure of \bite~when compared to LDA. Experimental and calculated results are compared in the spectral regions where distinct differences between the LDA and $GW$ results are present. Overall a superior agreement with $GW$ is found, highlighting the importance of many-body effects in the band structure of this family of topological insulators., 8 pages, 5 Figures

We proposed in our previous work V-substituted In2S3 as an intermediate band (IB) material able to enhance the efficiency of photovoltaic cells by combining two photons to achieve a higher energy electron excitation, much like natural photosynthesis. Here this hyper-doped material is tested in a photocatalytic reaction using wavelength-controlled light. The results evidence its ability to use photons with wavelengths of up to 750 nm, i.e. with energy significantly lower than the bandgap (=2.0 eV) of non-substituted In2S3, driving with them the photocatalytic reaction at rates comparable to those of non-substituted In2S3 in its photoactivity range (λ ≤ 650 nm). Photoluminescence spectra evidence that the same bandgap excitation as in V-free In2S3 occurs in V-substituted In2S3 upon illumination with photons in the same sub-bandgap energy range which is effective in photocatalysis, and its linear dependence on light intensity proves that this is not due to a nonlinear optical property. This evidences for the first time that a two-photon process can be active in photocatalysis in a single-phase material. Quantum calculations using GW-type many-body perturbation theory suggest that the new band introduced in the In2S3 gap by V insertion is located closer to the conduction band than to the valence band, so that hot carriers produced by the two-photon process would be of electron type; they also show that the absorption coefficients of both transitions involving the IB are of significant and similar magnitude. The results imply that V-substituted In2S3, besides being photocatalytically active in the whole visible light range (a property which could be used for the production of solar fuels), could make possible photovoltaic cells of improved efficiency., This work was supported by programme NUMANCIA-2 (nr. S2009ENE-1477) from the Comunidad de Madrid. Authors thankfully acknowledge the computer resources, technical expertise and assistance provided by the Centro de Supercomputación y Visualización de Madrid (CeSViMa) and the Spanish Supercomputing Network. R. L. also thanks CSIC for an I3P PhD grant.

We present one-shot $GW$ calculations of the bulk electronic structure of the topological insulators Bi${}_{2}$Se${}_{3}$ and Bi${}_{2}$Te${}_{3}$ within the all-electron full-potential linearized augmented-plane-wave formalism. We compare three different ways of treating the spin-orbit interaction in calculating the quasiparticle energies: (i) The spin-orbit coupling (SOC) is already incorporated in the noninteracting system that serves as starting point for the quasiparticle correction. (ii) The SOC is added in a second-variation approach only after the quasiparticle calculation has been performed in the absence of SOC. We found that the approximate treatment (ii) yields most quasiparticle bands with reasonable accuracy but does fail in the important band-gap region, where the SOC gives rise to a band inversion relevant for the topological properties of these materials. For example, Bi${}_{2}$Se${}_{3}$ is just on the brink of becoming a trivial semiconductor within this approximate approach, while it maintains its topological properties in the case of the consistent treatment (i). Finally, we consider another approach (iii), in which the SOC is included in the Green function $G$ as in (i), but neglected in the calculation of the screened Coulomb potential $W$. This approach gives results in very good agreement with the full treatment (i), but with a smaller numerical effort. We conclude that, in the high-symmetry directions studied, bulk Bi${}_{2}$Se${}_{3}$ is a direct-gap and Bi${}_{2}$Te${}_{3}$ an indirect-gap semiconductor with band gaps of 0.20 and 0.19 eV, respectively.

The management of endocervical adenocarcinoma is largely based on tumor size and depth of invasion (DOI); however, DOI is difficult to measure accurately. The surgical treatment includes resection of regional lymph nodes, even though most lymph nodes are negative and lymphadenectomies can cause significant morbidity. We have investigated alternative parameters to better identify patients at risk of node metastases. Cases of invasive endocervical adenocarcinoma from 12 institutions were reviewed, and clinical/pathologic features assessed: patients' age, tumor size, DOI, differentiation, lymph-vascular invasion, lymph node metastases, recurrences, and stage. Cases were classified according to a new pattern-based system into Pattern A (well-demarcated glands), B (early destructive stromal invasion arising from well-demarcated glands), and C (diffuse destructive invasion). In total, 352 cases (FIGO Stages I-IV) were identified. Patients' age ranged from 20 to 83 years (mean 45), DOI ranged from 0.2 to 27 mm (mean 6.73), and lymph-vascular invasion was present in 141 cases. Forty-nine (13.9%) demonstrated lymph node metastases. Using this new system, 73 patients (20.7%) with Pattern A tumors (all Stage I) were identified. None had lymph node metastases and/or recurrences. Ninety patients (25.6%) had Pattern B tumors, of which 4 (4.4%) had positive nodes; whereas 189 (53.7%) had Pattern C tumors, of which 45 (23.8%) had metastatic nodes. The proposed classification system can spare 20.7% of patients (Pattern A) of unnecessary lymphadenectomy. Patients with Pattern B rarely present with positive nodes. An aggressive approach is justified in patients with Pattern C. This classification system is simple, easy to apply, and clinically significant.

We present $GW$ calculations of the topological insulators Bi${}_{2}$Se${}_{3}$, Bi${}_{2}$Te${}_{3}$, and Sb${}_{2}$Te${}_{3}$ within the all-electron full-potential linearized augmented-plane-wave formalism. Quasiparticle effects produce significant qualitative changes in the band structures of these materials when compared to density functional theory (DFT), especially at the $\ensuremath{\Gamma}$ point, where band inversion takes place. There, the widely used perturbative one-shot $GW$ approach can produce unphysical band dispersions, as the quasiparticle wave functions are forced to be identical to the noninteracting single-particle states. We show that a treatment beyond the perturbative approach, which incorporates the off-diagonal $GW$ matrix elements and thus enables many-body hybridization to be effective in the quasiparticle wave functions, is crucial in these cases to describe the characteristics of the band inversion around the $\ensuremath{\Gamma}$ point in an appropriate way. In addition, this beyond one-shot $GW$ approach allows us to calculate the values of the ${Z}_{2}$ topological invariants and compare them with those previously obtained within DFT.

Using angle-resolved photoelectron spectroscopy and ab initio $GW$ calculations, we unambiguously show that the widely investigated three-dimensional topological insulator Bi${}_{2}$Se${}_{3}$ has a direct band gap at the $\ensuremath{\Gamma}$ point. Experimentally, this is shown by a three-dimensional band mapping in large fractions of the Brillouin zone. Theoretically, we demonstrate that the valence-band maximum is located at the $\ensuremath{\Gamma}$ point only if many-body effects are included in the calculation. Otherwise, it is found in a high-symmetry mirror plane away from the zone center.