478 research outputs found

    Role of remote interfacial phonons in the resistivity of graphene

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    The temperature (T\it T) dependence of electrical resistivity in graphene has been experimentally investigated between 10 and 400 K for samples prepared on various substrates; HfO2_2, SiO2_2 and h-BN. The resistivity of graphene shows a linear T\it T-dependence at low T\it T and becomes superlinear above a substrate-dependent transition temperature. The results are explained by remote interfacial phonon scattering by surface optical phonons at the substrates. The use of an appropriate substrate can lead to a significant improvement in the charge transport of graphene

    Stabilized electron emission from silicon coated carbon nanotubes for a high-performance electron source

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    The authors show that carbon nanotubes (CNTs) coated with an amorphous silicon layer around their periphery show enhanced and stable electron emission. The CNT-field emitter array was grown on silicon substrate through a resist-assisted patterning process. The CNTs become coated with silicon from the substrate, which is etched and redeposited onto the CNTs. The authors obtained enhanced and stabilized electron emission from the silicon coated CNTs with a turn-on field of 2 V/μm at an emission current density of 1 μA/ cm 2. The structure and electron emission properties of the functionalized emitters are discussed

    Electromagnetic String Fluid in Rolling Tachyon

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    We study Born-Infeld type effective action for unstable D3-brane system including a tachyon and an Abelian gauge field, and find the rolling tachyon with constant electric and magnetic fields as the most general homogeneous solution. Tachyonic vacua are characterized by magnitudes of the electric and magnetic fields and the angle between them. Analysis of small fluctuations in this background shows that the obtained configuration may be interpreted as a fluid consisting of string-like objects carrying electric and magnetic fields. They are stretched along one direction and the rolling tachyon move in a perpendicular direction to the strings. Direction of the propagating waves coincides with that of strings with velocity equal to electric field.Comment: LaTeX, 18 pages, 1 figure, minor correction

    Clinical and genomic assessment of PD-L1 SP142 expression in triple-negative breast cancer

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    Purpose: The SP142 PD-L1 assay is a companion diagnostic for atezolizumab in metastatic triple-negative breast cancer (TNBC). We strove to understand the biological, genomic, and clinical characteristics associated with SP142 PD-L1 positivity in TNBC patients. Methods: Using 149 TNBC formalin-fixed paraffin-embedded tumor samples, tissue microarray (TMA) and gene expression microarrays were performed in parallel. The VENTANA SP142 assay was used to identify PD-L1 expression from TMA slides. We next generated a gene signature reflective of SP142 status and evaluated signature distribution according to TNBCtype and PAM50 subtypes. A SP142 gene expression signature was identified and was biologically and clinically evaluated on the TNBCs of TCGA, other cohorts, and on other malignancies treated with immune checkpoint inhibitors (ICI). Results: Using SP142, 28.9% of samples were PD-L1 protein positive. The SP142 PD-L1-positive TNBC had higher CD8+ T cell percentage, stromal tumor-infiltrating lymphocyte levels, and higher rate of the immunomodulatory TNBCtype compared to PD-L1-negative samples. The recurrence-free survival was prolonged in PD-L1-positive TNBC. The SP142-guided gene expression signature consisted of 94 immune-related genes. The SP142 signature was associated with a higher pathologic complete response rate and better survival in multiple TNBC cohorts. In the TNBC of TCGA, this signature was correlated with lymphocyte-infiltrating signature scores, but not with tumor mutational burden or total neoantigen count. In other malignancies treated with ICIs, the SP142 genomic signature was associated with improved response and survival. Conclusions: We provide multi-faceted evidence that SP142 PDL1-positive TNBC have immuno-genomic features characterized as highly lymphocyte-infiltrated and a relatively favorable survival

    Metagenes Associated with Survival in Non-Small Cell Lung Cancer

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    NSCLC (non-small cell lung cancer) comprises about 80% of all lung cancer cases worldwide. Surgery is most effective treatment for patients with early-stage disease. However, 30%–55% of these patients develop recurrence within 5 years. Therefore, markers that can be used to accurately classify early-stage NSCLC patients into different prognostic groups may be helpful in selecting patients who should receive specific therapies

    Carotid Intima-Media Thickness Progression as Surrogate Marker for Cardiovascular Risk Meta-Analysis of 119 Clinical Trials Involving 100 667 Patients

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    Background: To quantify the association between effects of interventions on carotid intima-media thickness (cIMT) progression and their effects on cardiovascular disease (CVD) risk. Methods: We systematically collated data from randomized, controlled trials. cIMT was assessed as the mean value at the common-carotid-artery; if unavailable, the maximum value at the common-carotid-artery or other cIMT measures were used. The primary outcome was a combined CVD end point defined as myocardial infarction, stroke, revascularization procedures, or fatal CVD. We estimated intervention effects on cIMT progression and incident CVD for each trial, before relating the 2 using a Bayesian meta-regression approach. Results: We analyzed data of 119 randomized, controlled trials involving 100 667 patients (mean age 62 years, 42% female). Over an average follow-up of 3.7 years, 12 038 patients developed the combined CVD end point. Across all interventions, each 10 μm/y reduction of cIMT progression resulted in a relative risk for CVD of 0.91 (95% Credible Interval, 0.87–0.94), with an additional relative risk for CVD of 0.92 (0.87–0.97) being achieved independent of cIMT progression. Taken together, we estimated that interventions reducing cIMT progression by 10, 20, 30, or 40 μm/y would yield relative risks of 0.84 (0.75–0.93), 0.76 (0.67–0.85), 0.69 (0.59–0.79), or 0.63 (0.52–0.74), respectively. Results were similar when grouping trials by type of intervention, time of conduct, time to ultrasound follow-up, availability of individual-participant data, primary versus secondary prevention trials, type of cIMT measurement, and proportion of female patients. Conclusions: The extent of intervention effects on cIMT progression predicted the degree of CVD risk reduction. This provides a missing link supporting the usefulness of cIMT progression as a surrogate marker for CVD risk in clinical trials

    Production of Coturnix quail immunoglobulins Y (IgYs) against Vibrio parahaemolyticus and Vibrio vulnificus

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    This research article published by Springer Nature Switzerland AG., 2011Production of chicken immunoglobulins Y (IgYs) and their applications in prophylactic, therapeutic, detection of microbial contaminants and as a diagnostic tool has been widely studied with limited information from other avians. This study produced Coturnix quail (Coturnix coturnix japonica) egg yolk IgYs against Vibrio parahaemolyticus and Vibrio vulnificus. Formalin inactivated (FIVP, FIVV, mixed FI-VP/VV) and heat inactivated (HIVP, HIVV, mixed HI-VP/VV) Vibrio immunogens (109 CFU/mL) were intramuscularly immunized into quail through thigh muscles. Egg yolk IgY was purified by water dilution-ammonium sulfate precipitation method and the activity was determined by enzyme-linked immunosorbent assay (ELISA). Formalin inactivated immunogens induced high humoral immune response for both V. parahaemolyticus and V. vulnificus over heat inactivated immunogens. However, IgYs resulted from HIVP and FIVV immunogens, showed high specificity to V. parahaemolyticus and V. vulnificus respectively. Detection limits of the indirect ELISA using the produced IgYs were 105 CFU/mL for V. parahaemolyticus and 106 CFU/mL for V. vulnificus. The developed antibodies showed high binding affinity to their corresponding immunogens, very little cross reactivity to Staphylococcus aureus and not other bacteria strains (p<0.05), a phenomenon which was also observed in Western blot
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