947 research outputs found
Adaptive control with neural networks-based disturbance observer for a spherical UAV
This paper develops a control scheme for a Spherical Unmanned Aerial Vehicle (UAV) which can be used in complex scenarios where traditional navigation and communications systems would not succeed. The proposed scheme is based on the nonlinear control theory combined with Adaptive Neural-Networks Disturbance Observer (NN-DOB) and controls the attitude and altitude of the UAV in presence of model uncertainties and external disturbances. The NN-DOB can effectively estimate the uncertainties without the knowledge of their bounds and the control system stability is proven using Lyapunov’s stability theorems. Numerical simulation results demonstrate the validity of the proposed method on the UAV under model uncertainties and external disturbances
Universal quantum control of an atomic spin qubit on a surface
Scanning tunneling microscopy (STM) enables the bottom-up fabrication of tailored spin systems on a surface that are engineered with atomic precision. When combining STM with electron spin resonance (ESR), these single atomic and molecular spins can be controlled quantum-coherently and utilized as electron-spin qubits. Here we demonstrate universal quantum control of such a spin qubit on a surface by employing coherent control along two distinct directions, achieved with two consecutive radio-frequency (RF) pulses with a well-defined phase difference. We first show transformations of each Cartesian component of a Bloch vector on the quantization axis, followed by ESR-STM detection. Then we demonstrate the ability to generate an arbitrary superposition state of a single spin qubit by using two-axis control schemes, in which experimental data show excellent agreement with simulations. Finally, we present an implementation of two-axis control in dynamical decoupling. Our work extends the scope of STM-based pulsed ESR, highlighting the potential of this technique for quantum gate operations of electron-spin qubits on a surface
Physical properties of metal-doped zinc oxide films for surface acoustic wave application
Metal-doped ZnO [MZO] thin films show changes of the following properties by a dopant. First, group III element (Al, In, Ga)-doped ZnO thin films have a high conductivity having an n-type semiconductor characteristic. Second, group I element (Li, Na, K)-doped ZnO thin films have high resistivity due to a dopant that accepts a carrier. The metal-doped ZnO (M = Li, Ag) films were prepared by radio frequency magnetron sputtering on glass substrates with the MZO targets. We investigated on the optical and electrical properties of the as-sputtered MZO films as dependences on the doping contents in the targets. All the MZO films had shown a preferred orientation in the [002] direction. As the quantity and the variety of metal dopants were changed, the crystallinity and the transmittance, as well as optical band gap were changed. The electrical resistivity was also changed with changing metal doping amounts and kinds of dopants. An epitaxial Li-doped ZnO film has a high resistivity and very smooth surface; it will have the most optimum conditions which can be used for the piezoelectric devices
Application of Neuroanatomical Ontologies for Neuroimaging Data Annotation
The annotation of functional neuroimaging results for data sharing and re-use is particularly challenging, due to the diversity of terminologies of neuroanatomical structures and cortical parcellation schemes. To address this challenge, we extended the Foundational Model of Anatomy Ontology (FMA) to include cytoarchitectural, Brodmann area labels, and a morphological cortical labeling scheme (e.g., the part of Brodmann area 6 in the left precentral gyrus). This representation was also used to augment the neuroanatomical axis of RadLex, the ontology for clinical imaging. The resulting neuroanatomical ontology contains explicit relationships indicating which brain regions are “part of” which other regions, across cytoarchitectural and morphological labeling schemas. We annotated a large functional neuroimaging dataset with terms from the ontology and applied a reasoning engine to analyze this dataset in conjunction with the ontology, and achieved successful inferences from the most specific level (e.g., how many subjects showed activation in a subpart of the middle frontal gyrus) to more general (how many activations were found in areas connected via a known white matter tract?). In summary, we have produced a neuroanatomical ontology that harmonizes several different terminologies of neuroanatomical structures and cortical parcellation schemes. This neuroanatomical ontology is publicly available as a view of FMA at the Bioportal website1. The ontological encoding of anatomic knowledge can be exploited by computer reasoning engines to make inferences about neuroanatomical relationships described in imaging datasets using different terminologies. This approach could ultimately enable knowledge discovery from large, distributed fMRI studies or medical record mining
Small anisotropy of the lower critical field and -wave two-gap feature in single crystal LiFeAs
The in- and out-of-plane lower critical fields and magnetic penetration
depths for LiFeAs were examined. The anisotropy ratio is
smaller than the expected theoretical value, and increased slightly with
increasing temperature from 0.6 to . This small degree of anisotropy
was numerically confirmed by considering electron correlation effect. The
temperature dependence of the penetration depths followed a power
law() below 0.3, with 3.5 for both and
. Based on theoretical studies of iron-based superconductors, these
results suggest that the superconductivity of LiFeAs can be represented by an
extended -wave due to weak impurity scattering effect. And the
magnitudes of the two gaps were also evaluted by fitting the superfluid density
for both the in- and out-of-plane to the two-gap model. The estimated values
for the two gaps are consistent with the results of angle resolved
photoemission spectroscopy and specific heat experiments.Comment: 10 pages, 5 figure
Heterogeneous nuclear ribonucleoprotein A1 regulates rhythmic synthesis of mouse Nfil3 protein via IRES-mediated translation.
Nuclear factor, interleukin 3, regulated (Nfil3, also known as E4 Promoter-Binding Protein 4 (E4BP4)) protein is a transcription factor that binds to DNA and generally represses target gene expression. In the circadian clock system, Nfil3 binds to a D-box element residing in the promoter of clock genes and contributes to their robust oscillation. Here, we show that the 5'-untranslated region (5'-UTR) of Nfil3 mRNA contains an internal ribosome entry site (IRES) and that IRES-mediated translation occurs in a phase-dependent manner. We demonstrate that heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) binds to a specific region of Nfil3 mRNA and regulates IRES-mediated translation. Knockdown of hnRNP A1 almost completely abolishes protein oscillation without affecting mRNA oscillation. Moreover, we observe that intracellular calcium levels, which are closely related to bone formation, depend on Nfil3 levels in osteoblast cell lines. We suggest that the 5'-UTR mediated cap-independent translation of Nfil3 mRNA contributes to the rhythmic expression of Nfil3 by interacting with the RNA binding protein hnRNP A1. These data provide new evidence that the posttranscriptional regulation of clock gene expression is important during bone metabolism.1131Ysciescopu
Wide-field extended-resolution fluorescence microscopy with standing surface-plasmon-resonance waves
The resolution of conventional SPR imaging has been limited by the diffraction nature of light. A wide-field extended-resolution optical imaging technique, standing-wave surface plasmon resonance fluorescence (SW-SPRF) microscopy, has been developed. Based on evanescent SPR standing waves, SW-SPRF provides lateral resolution approaching 100 nm and offers the advantages of significant signal enhancement and background noise reduction. SW-SPRF has the potential for sensitive biomolecular detection, nanoscale imaging, and lithographic applications
Treatment Choices Based on Onco type
Introduction. This study aimed to evaluate whether OncotypeDx test results predict receipt of adjuvant chemotherapy in breast cancer patients who received an OncotypeDx recurrence score (RS). Materials and Methods. Pathology records were used to identify breast cancer patients who had OncotypeDx testing between December 2004 and January 2009 (n=118). Patient sociodemographic information, tumor characteristics, RS, and treatment-specific data were collected via chart review. RS was classified as follows: low (RS≤17), intermediate (RS = 18–30), or high (RS≥31). Bivariate analyses were conducted to investigate the relationship between adjuvant chemotherapy receipt and each sociodemographic and clinical characteristic; significant sociodemographic and clinical variables were included in a multivariable logistic regression model. Results. In multivariable analysis controlling for tumor size, histologic grade, and nuclear grade, only RS remained significantly associated with chemotherapy uptake. Relative to low RS, an intermediate (adjusted odds ratio [AOR], 21.24; 95% confidence interval [CI], 3.62–237.52) or high (AOR, 15.07; 95% CI, 1.28–288.21) RS was associated with a greater odds of chemotherapy uptake. Discussion. Results indicate that RS was significantly associated with adjuvant chemotherapy uptake, suggesting that OncotypeDx results were used to inform treatment decision making, although it is unclear if and how the information was conveyed to patients
Predictors of high-cost hospitalization in the treatment of acute coronary syndrome in Asia: findings from EPICOR Asia.
BACKGROUND: The EPICOR Asia (long-tErm follow-uP of antithrombotic management patterns In acute CORonary syndrome patients in Asia) study (NCT01361386) was an observational study of patients hospitalized for acute coronary syndromes (ACS) enrolled in 218 hospitals in eight countries/regions in Asia. This study examined costs, length of stay and the predictors of high costs during an ACS hospitalization. METHODS AND RESULTS: Data for patients hospitalized for an ACS (n = 12,922) were collected on demographics, medical history, event characteristics, socioeconomic and insurance status at discharge. Patients were followed up at 6 weeks' post-hospitalization for an ACS event to assess associated treatment costs from a health sector perspective. Primary outcome was the incurring of costs in the highest quintile by country and index event diagnosis, and identification of associated predictors. Cost data were available for 10,819 patients. Mean length of stay was 10.1 days. The highest-cost countries were China, Singapore, and South Korea. Significant predictors of high-cost care were age, male sex, income, country, prior disease history, hospitalization in 3 months before index event, no dependency before index event, having an invasive procedure, hospital type and length of stay. CONCLUSIONS: Substantial variability exists in healthcare costs for hospitalized ACS patients across Asia. Of concern is the observation that the highest costs were reported in China, given the rapidly increasing numbers of procedures in recent years. TRIAL REGISTRATION: NCT01361386
Protective Effect of the Fruit Hull of Gleditsia sinensis on LPS-Induced Acute Lung Injury Is Associated with Nrf2 Activation
The fruit hull of Gleditsia sinensis (FGS) has been prescribed as a traditional eastern Asian medicinal remedy for the treatment of various respiratory diseases, but the efficacy and underlying mechanisms remain poorly characterized. Here, we explored a potential usage of FGS for the treatment of acute lung injury (ALI), a highly fatal inflammatory lung disease that urgently needs effective therapeutics, and investigated a mechanism for the anti-inflammatory activity of FGS. Pretreatment of C57BL/6 mice with FGS significantly attenuated LPS-induced neutrophilic lung inflammation compared to sham-treated, inflamed mice. Reporter assays, semiquantitative RT-PCR, and Western blot analyses show that while not affecting NF-κB, FGS activated Nrf2 and expressed Nrf2-regulated genes including GCLC, NQO-1, and HO-1 in RAW 264.7 cells. Furthermore, pretreatment of mice with FGS enhanced the expression of GCLC and HO-1 but suppressed that of proinflammatory cytokines in including TNF-α and IL-1β in the inflamed lungs. These results suggest that FGS effectively suppresses neutrophilic lung inflammation, which can be associated with, at least in part, FGS-activating anti-inflammatory factor Nrf2. Our results suggest that FGS can be developed as a therapeutic option for the treatment of ALI
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