1,532 research outputs found
Staggered local density-of-states around the vortex in underdoped cuprates
We have studied a single vortex with the staggered flux (SF) core based on
the SU(2) slave-boson theory of high superconductors. We find that
whereas the center in the vortex core is a SF state, as one moves away from the
core center, a correlated staggered modulation of the hopping amplitude
and pairing amplitude becomes predominant. We predict that in this
region, the local density-of-states (LDOS) exhibits staggered modulation when
measured on the bonds, which may be directly detected by STM experiments.Comment: 4 pages, 3 figure
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Cathelicidin preserves intestinal barrier function in polymicrobial sepsis.
ObjectivesThe intestinal epithelium compartmentalizes the sterile bloodstream and the commensal bacteria in the gut. Accumulating evidence suggests that this barrier is impaired in sepsis, aggravating systemic inflammation. Previous studies reported that cathelicidin is differentially expressed in various tissues in sepsis. However, its role in sepsis-induced intestinal barrier dysfunction has not been investigated.DesignTo examine the role of cathelicidin in polymicrobial sepsis, cathelicidin wild-(Cnlp+/+) and knockout (Cnlp-/-) mice underwent cecal-ligation and puncture (CLP) followed by the assessment of septic mortality and morbidity as well as histological, biochemical, immunological, and transcriptomic analyses in the ileal tissues. We also evaluated the prophylactic and therapeutic efficacies of vitamin D3 (an inducer of endogenous cathelicidin) in the CLP-induced murine polymicrobial sepsis model.ResultsThe ileal expression of cathelicidin was increased by three-fold after CLP, peaking at 4 h. Knockout of Cnlp significantly increased 7-day mortality and was associated with a higher murine sepsis score. Alcian-blue staining revealed a reduced number of mucin-positive goblet cells, accompanied by reduced mucin expression. Increased number of apoptotic cells and cleavage of caspase-3 were observed. Cnlp deletion increased intestinal permeability to 4kD fluorescein-labeled dextran and reduced the expression of tight junction proteins claudin-1 and occludin. Notably, circulating bacterial DNA load increased more than two-fold. Transcriptome analysis revealed upregulation of cytokine/inflammatory pathway. Depletion of Cnlp induced more M1 macrophages and neutrophils compared with the wild-type mice after CLP. Mice pre-treated with cholecalciferol (an inactive form of vitamin D3) or treated with 1alpha, 25-dihydroxyvitamin D3 (an active form of VD3) had decreased 7-day mortality and significantly less severe symptoms. Intriguingly, the administration of cholecalciferol after CLP led to worsened 7-day mortality and the associated symptoms.ConclusionsEndogenous cathelicidin promotes intestinal barrier integrity accompanied by modulating the infiltration of neutrophils and macrophages in polymicrobial sepsis. Our data suggested that 1alpha, 25-dihydroxyvitamin D3 but not cholecalciferol is a potential therapeutic agent for treating sepsis
Fractal Profit Landscape of the Stock Market
We investigate the structure of the profit landscape obtained from the most
basic, fluctuation based, trading strategy applied for the daily stock price
data. The strategy is parameterized by only two variables, p and q. Stocks are
sold and bought if the log return is bigger than p and less than -q,
respectively. Repetition of this simple strategy for a long time gives the
profit defined in the underlying two-dimensional parameter space of p and q. It
is revealed that the local maxima in the profit landscape are spread in the
form of a fractal structure. The fractal structure implies that successful
strategies are not localized to any region of the profit landscape and are
neither spaced evenly throughout the profit landscape, which makes the
optimization notoriously hard and hypersensitive for partial or limited
information. The concrete implication of this property is demonstrated by
showing that optimization of one stock for future values or other stocks
renders worse profit than a strategy that ignores fluctuations, i.e., a
long-term buy-and-hold strategy.Comment: 12 pages, 4 figure
Leptonic Decays of the W-Boson in a Strong Electromagnetic Field
The probability of W-boson decay into a lepton and a neutrino in a strong
electromagnetic field is calculated. On the basis of the method for deriving
exact solutions to relativistic wave equations for charged particles, an exact
analytic expression is obtained for the partial W-decay width at an arbitrary
value of the external field strength. It is found that, in the region of
comparatively weak fields, field-induced corrections to the standard decay
width of the W-boson in a vacuum are about a few percent. In these conditions
at first we observe the decrease of the W-boson partial decay width with the
increase of the external field strength parameter. At absolute minimum the
W-width deviates from the corresponding vacuum value by a factor 0,926. Then
with further augmentation of the background field intensity the W-boson decay
width grows monotonously. In superstrong fields the partial W-width is greater
than the corresponding one in vacuum in a dozen of times.Comment: LaTex file, 19 pages, 2 Postscript figur
Signature of the staggered flux state around a superconducting vortex in underdoped cuprates
Based on the SU(2) lattice gauge theory formulation of the t-J model, we
discuss possible signature of the unit cell doubling associated with the
staggered flux (SF) state in the lightly doped spin liquid. Although the SF
state appears only dynamically in a uniform d-wave superconducting (SC) state,
a topological defect [SU(2) vortex] freezes the SF state inside the vortex
core. Consequently, the unit cell doubling shows up in the hopping
() and pairing () order parameters of physical
electrons. We find that whereas the center in the vortex core is a SF state, as
one moves away from the core center, a correlated staggered modulation of
and becomes predominant. We predict that over the
region outside the core and inside the internal gauge field penetration depth
around a vortex center, the local density-of-states (LDOS) exhibits staggered
peak-dip (SPD) structure inside the V-shaped profile when measured on the
bonds. The SPD structure has its direct origin in the unit cell doubling
associated with the SF core and the robust topological texture, which has
little to do with the symmetry of the d-wave order parameter. Therefore the
structure may survive the tunneling matrix element effects and easily be
detected by STM experiment.Comment: 27 pages, 14 figures in GIF format, typo correcte
Dual-gated bilayer graphene hot electron bolometer
Detection of infrared light is central to diverse applications in security,
medicine, astronomy, materials science, and biology. Often different materials
and detection mechanisms are employed to optimize performance in different
spectral ranges. Graphene is a unique material with strong, nearly
frequency-independent light-matter interaction from far infrared to
ultraviolet, with potential for broadband photonics applications. Moreover,
graphene's small electron-phonon coupling suggests that hot-electron effects
may be exploited at relatively high temperatures for fast and highly sensitive
detectors in which light energy heats only the small-specific-heat electronic
system. Here we demonstrate such a hot-electron bolometer using bilayer
graphene that is dual-gated to create a tunable bandgap and
electron-temperature-dependent conductivity. The measured large electron-phonon
heat resistance is in good agreement with theoretical estimates in magnitude
and temperature dependence, and enables our graphene bolometer operating at a
temperature of 5 K to have a low noise equivalent power (33 fW/Hz1/2). We
employ a pump-probe technique to directly measure the intrinsic speed of our
device, >1 GHz at 10 K.Comment: 5 figure
Development of a LAMP assay for detection of Leishmania infantum infection in dogs using conjunctival swab samples
Background: Leishmania infantum infections in dogs play a crucial role in the transmission of pathogens causing visceral leishmaniasis to humans in the Gansu province, northwest China. To be able to control zoonotic transmission of the parasite to humans, a non-invasive loop-mediated isothermal amplification (LAMP) assay to specifically detect L. infantum infections in dogs was developed. Methods: The primers used in the LAMP assay were designed to target kinetoplast DNA minicircle sequences of the L. infantum isolate MCAN/CN/90/SC and tested using DNA isolated from promastigotes of different Leishmania species. The LAMP assay was evaluated with conjunctional swab samples obtained from 111 and 33 dogs living in an endemic and a non-endemic region of zoonotic visceral leishmaniasis in the Gansu province, respectively. The LAMP assay was also compared with conventional PCR, ELISA and microscopy using conjunctional swab, serum and bone marrow samples from the dogs, respectively. Results: The LAMP assay detected 1 fg of L. infantum DNA purified from cultured promastigotes which was 10-fold more sensitive than a conventional PCR test using Leishmania genus-specific primers. No cross reaction was observed with DNA isolated from promastigotes of L. donovani, L. major, L. tropica, and L. braziliensis, and the L. infantum reference strain MHOM/TN/80/IPT1. The L. infantum-positive rates obtained for field-collected samples were 61.3%, 58.6%, 40.5% and 10.8% by LAMP, PCR, ELISA and microscopy, respectively. As only one out of the 33 samples from control dogs from the non-endemic region of zoonotic visceral leishmaniasis was positive by the LAMP assay and the PCR test, the observed true negative rate (specificity) was 97% for both methods. Conclusion: This study has shown that the non-invasive, conjunctional swab-based LAMP assay developed was more sensitive in the detection of leishmaniasis in dogs than PCR, ELISA and microscopy. The findings indicate that the LAMP assay is a sensitive and specific method for the field surveillance of domestic dogs, particularly of asymptomatic canines, in ZVL-endemic areas in western China
Multi-factor service design: identification and consideration of multiple factors of the service in its design process
Service design is a multidisciplinary area that helps innovate services by bringing new ideas to customers through a design-thinking approach. Services are affected by multiple factors, which should be considered in designing services. In this paper, we propose the multi-factor service design (MFSD) method, which helps consider the multi-factor nature of service in the service design process. The MFSD method has been developed through and used in five service design studies with industry and government. The method addresses the multi-factor nature of service for systematic service design by providing the following guidelines: (1) identify key factors that affect the customer value creation of the service in question (in short, value creation factors), (2) define the design space of the service based on the value creation factors, and (3) design services and represent them based on the factors. We provide real stories and examples from the five service design studies to illustrate the MFSD method and demonstrate its utility. This study will contribute to the design of modern complex services that are affected by varied factors
Facile Synthesis of Three-Dimensional ZnO Nanostructure: Realization of a Multifunctional Stable Superhydrophobic Surface
BACKGROUND: After comprehensive study of various superhydrophobic phenomena in nature, it is no longer a puzzle for researchers to realize such fetching surfaces. However, the different types of artificial surfaces may get wetted and lose its water repellence if there exist defects or the liquid is under pressure. With respect to the industry applications, in which the resistance of wetting transition is critical important, new nanostructure satisfied a certain geometric criterion should be designed to hold a stable gas film at the base area to avoid the wet transition. METHODOLOGY: A thermal deposition method was utilized to produce a thin ZnO seeds membrane on the aluminum foil. And then a chemical self-assemble technology was developed in present work to fabricate three-dimensional (3D) hierarchical dune-like ZnO architecture based on the prepared seeds membrane. RESULTS: Hierarchical ZnO with micro scale dune-like structure and core-sharing nanosheets was generated. The characterization results showed that there exist plenty of gaps and interfaces among the micro-dune and nanosheets, and thus the surface area was enlarged by such a unique morphology. Benefited from this unique 3D ZnO hierarchical nanostructure, the obtained surface exhibited stable water repellency after modification with Teflon, and furthermore, based on solid theory analysis, such 3D ZnO nanostructure would exhibit excellent sensing performance
Allogeneic hematopoietic stem cell transplantation in China: where we are and where to go
Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an effective and sometimes the only curative therapy for patients with certain hematological diseases. Allo-HSCT has been practiced in China for approximately 30 years, and great improvements have been made within the past decade, particularly in fields such as the haploidentical HSCT system, strategies to overcome relapse and GVHD, and modified HSCT for elderly patients. This review will describe the current situation and provide a prospective of these unique aspects of Allo-HSCT in China
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