Strong One-Dimensional Characteristics of Hole-Carriers in ReS2 and ReSe2.

Each plane of layered ReS2 and ReSe2 materials has 1D chain structure, from which intriguing properties such as 1D character of the exciton states and linearly polarized photoluminescence originate. However, systematic studies on the 1D character of charge carriers have not been done yet. Here, we report on systematic and comparative studies on the energy-momentum dispersion relationships of layered transition metal dichalcogenides ReS2 and ReSe2 by angle resolved photoemission. We found that the valence band maximum or the minimum energy for holes is located at the high symmetric Z-point for both materials. However, the out-of-plane ([Formula: see text]) dispersion for ReSe2 (20 meV) is found to be much smaller than that of ReS2 (150 meV). We observe that the effective mass of the hole carriers along the direction perpendicular to the chain is about 4 times larger than that along the chain direction for both ReS2 and ReSe2. Remarkably, the experimentally measured hole effective mass is about twice heavier than that from first principles calculation for ReS2 although the in-plane anisotropy values from the experiment and calculations are comparable. These observation indicate that bulk ReS2 and ReSe2 are unique semiconducting transition metal dichalcogenides having strong one-dimensional characters

Recurrence of Ganglion Cysts Following Re-excision

Previous studies have examined the recurrence of ganglion cysts after surgical excision at a rate of 4 to 40%. However, recurrence after revision surgical excision is unknown. The purpose of this study was to define the incidence of recurrent ganglion cysts in patients who underwent a 2nd excisional procedure.https://jdc.jefferson.edu/cwicposters/1032/thumbnail.jp

Device-Related Adverse Events From WATCHMAN FLX Implants As Reported By The Food And Drug Administration

https://scholarscompass.vcu.edu/gradposters/1147/thumbnail.jp

Superconductivity below 20 K in heavily electron-doped surface layer of FeSe bulk crystal

A superconducting transition temperature (T-c) as high as 100 K was recently discovered in one monolayer FeSe grown on SrTiO3. The discovery ignited efforts to identify the mechanism for the markedly enhanced T-c from its bulk value of 8 K. There are two main views about the origin of the T-c enhancement: interfacial effects and/or excess electrons with strong electron correlation. Here, we report the observation of superconductivity below 20 K in surface electron-doped bulk FeSe. The doped surface layer possesses all the key spectroscopic aspects of the monolayer FeSe on SrTiO3. Without interfacial effects, the surface layer state has a moderate T-c of 20 K with a smaller gap opening of 4.2 meV. Our results show that excess electrons with strong correlation cannot induce the maximum T-c, which in turn reveals the need for interfacial effects to achieve the highest T-c in one monolayer FeSe on SrTiO3.1116Ysciescopu

An M Theory Solution to the Strong CP Problem and Constraints on the Axiverse

We give an explicit realization of the "String Axiverse" discussed in Arvanitaki et. al \cite{Arvanitaki:2009fg} by extending our previous results on moduli stabilization in $M$ theory to include axions. We extend the analysis of \cite{Arvanitaki:2009fg} to allow for high scale inflation that leads to a moduli dominated pre-BBN Universe. We demonstrate that an axion which solves the strong-CP problem naturally arises and that both the axion decay constants and GUT scale can consistently be around $2\times 10^{16}$ GeV with a much smaller fine tuning than is usually expected. Constraints on the Axiverse from cosmological observations, namely isocurvature perturbations and tensor modes are described. Extending work of Fox et. al \cite{Fox:2004kb}, we note that {\it the observation of tensor modes at Planck will falsify the Axiverse completely.} Finally we note that Axiverse models whose lightest axion has mass of order $10^{-15}$ eV and with decay constants of order $5\times 10^{14}$ GeV require no (anthropic) fine-tuning, though standard unification at $10^{16}$ GeV is difficult to accommodate.Comment: 16 pages, 8 figures, v2 References adde

Inorganic-ligand exchanging time effect in PbS quantum dot solar cell

We investigate time-dependent inorganic ligand exchanging effect and photovoltaic performance of lead sulfide (PbS) nanocrystal films. With optimal processing time, volume shrinkage induced by residual oleic acid of the PbS colloidal quantum dot (CQD) was minimized and a crack-free film was obtained with improved flatness. Furthermore, sufficient surface passivation significantly increased the packing density by replacing from long oleic acid to a short iodide molecule. It thus facilities exciton dissociation via enhanced charge carrier transport in PbS CQD films, resulting in the improved power conversion efficiency from 3.39% to 6.62%. We also found that excess iodine ions on the PbS surface rather hinder high photovoltaic performance of the CQD solar cell

RGO/Nylon-6 composite mat with unique structural features and electrical properties obtained from electrospinning and hydrothermal process

In this work, the reduced graphene oxide (RGO) sheets were effectively uploaded through nylon-6 fibers using combined process of electrospinning and hydrothermal treatment. Good dispersion of graphene oxide (GO) with nylon-6 solution could allow to upload GO sheets through nylon-6 fibers and facilitate the formation of spider-wave-like nano-nets during electrospinning. GO sheets present on/into nylon-6 spider-wave-like nano-nets were further reduced to RGO using hydrothermal treatment. The impregnated GO sheets into nylon-6 nanofibers and their reduction during hydrothermal treatment were confirmed by FE-SEM, TEM, FT-IR and Raman spectra. The electrical characteristics of pristine nylon-6, GO/nylon-6 and RGO/nylon-6 nanofibers were investigated and it was found that RGO/nylon-6 composite mat had better electrical conductivity than others. The formation of spider-wave-like nano-nets as well as indirect route of incorporation of RGO sheets on electrospun nylon-6 mat may open a new direction for future graphene/polymer electronics. © 2013 The Korean Fiber Society and Springer Science+Business Media Dordrecht

Pheochromocytoma with IVC Invasion: Case Report & Systematic Review of Literature

Surgical management and outcome of pheochromocytoma with invasion of the inferior vena cava (IVC) has not been thoroughly reported or widely available in the literature. As determining the malignancy of pheochromocytoma has yet to be clearly defined and the experience of surgical resection of this condition is underrepresented, we include a case report and a systematic literature review on this condition. A literature search in PubMed was performed based on a recent review article by Kassahun et al. (2016). The search yielded 13 case reports between 1988 and 2014 from which data was extracted based on the following variables: patient’s age, gender, comorbidities, laboratory tests for pheochromocytoma diagnosis, size and laterality of the tumor, diagnostic test for IVC invasion, preoperative treatment and imaging, perioperative procedures, and oncological outcomes. The mean age of the patients was 49.4 years, with 38.5% being female (n=5) and 53.3% being male (n=8). 92% (n=12) of the cases were right-sided pheochromocytomas that invaded the IVC, with only one case of pheochromocytoma localized in the organ of Zuckerkandl. Only 46.7% (n=7) of the cases reported using laboratory tests to diagnose pheochromocytoma while only 53.3% (n=8) specifically reported using imaging techniques (CT, MRI, ultrasound, CTA, inferior venacavogram, MIBG-scintigraphy) to diagnose IVC invasion. Four of the surgical cases were performed without cardiopulmonary bypass while three specifically mentioned the use of the bypass technique. There was also further variance in surgical approach as some were performed via sternotomy, thoracophrenolaparotomy, or thoracoabdominal approach to completely resect the tumor and IVC, or to perform a cavotomy with no reconstruction of the IVC necessary. Follow-up of only 8 patients were noted, all of which revealed no evidence of disease, although at different time points post-op. The lack of a thorough and consistent report on pheochromocytoma cases with IVC invasion makes it difficult to compare the management of this condition. We hope a comprehensive review of these patient cases provides greater insight into the diagnosis of pheochromocytoma with IVC invasion and the characteristics and surgical procedure of this tumor invasion that would eliminate recurrence

Aging Logarithmic Conformal Field Theory : a holographic view

We consider logarithmic extensions of the correlation and response functions of scalar operators for the systems with aging as well as Schr\"odinger symmetry. Aging is known to be the simplest nonequilibrium phenomena, and its physical significances can be understood by the two-time correlation and response functions. Their logarithmic part is completely fixed by the bulk geometry in terms of the conformal weight of the dual operator and the dual particle number. Motivated by recent experimental realizations of Kardar-Parisi-Zhang universality class in growth phenomena and its subsequent theoretical extension to aging, we investigate our two-time correlation functions out of equilibrium, which show several qualitatively different behaviors depending on the parameters in our theory. They exhibit either growing or aging, i.e. power-law decaying, behaviors for the entire range of our scaling time. Surprisingly, for some parameter ranges, they exhibit growing at early times as well as aging at later times.Comment: 1+26 pages, 15 figure

Sexual reproduction and genetic polymorphism within the cosmopolitan marine diatom Pseudo-nitzschia pungens.

Different clades belonging to the cosmopolitan marine diatom Pseudo-nitzschia pungens appear to be present in different oceanic environments, however, a 'hybrid zone', where populations of different clades interbreed, has also been reported. Many studies have investigated the sexual reproduction of P. pungens, focused on morphology and life cycle, rather than the role of sexual reproduction in mixing the genomes of their parents. We carried out crossing experiments to determine the sexual compatibility/incompatibility between different clades of P. pungens, and examined the genetic polymorphism in the ITS2 region. Sexual reproduction did not occur only between clades II and III under any of experimental temperature conditions. Four offspring strains were established between clade I and III successfully. Strains established from offspring were found interbreed with other offspring strains as well as viable with their parental strains. We confirmed the hybrid sequence patterns between clades I and III and found novel sequence types including polymorphic single nucleotide polymorphisms (SNPs) in the offspring strains. Our results implicate that gene exchange and mixing between different clades are still possible, and that sexual reproduction is a significant ecological strategy to maintain the genetic diversity within this diatom species