gebhart/patrepeval huggingface dataset:
Controlling propagation and coupling of waveguide modes using phase-gradient metasurfaces (2017)

Research on two-dimensional designer optical structures, or metasurfaces, has mainly focused on controlling the wavefronts of light propagating in free space. Here, we show that gradient metasurface structures consisting of phased arrays of plasmonic or dielectric nanoantennas can be used to control guided waves via strong optical scattering at subwavelength intervals. Based on this design principle, we experimentally demonstrate waveguide mode converters, polarization rotators and waveguide devices supporting asymmetric optical power transmission. We also demonstrate all-dielectric on-chip polarization rotators based on phased arrays of Mie resonators with negligible insertion losses. Our gradient metasurfaces can enable small-footprint, broadband and low-loss photonic integrated devices.
Molecular modelling study of 2-phenylethynyladenosine (PEAdo) derivatives as highly selective A3 adenosine receptor ligands (2006)

A series of 2-phenylethynyladenosine (PEAdo) derivatives substituted in the N⁶- and 4'-position was synthesised and the new derivatives were tested at the four human adenosine receptors stably transfected into Chinese hamster ovary (CHO) cells, using radioligand binding studies (A₁, A(₂A), A₃) or adenylyl cyclase activity assay (A(₂B)). Binding studies showed that the presence of a phenyl ethynyl group in the 2 position of adenosine favoured the interaction with A₃ receptors, resulting in compounds endowed with high affinity and selectivity for the A₃ subtype. Additional substitution of the N⁶- and 4'-position increases both A₃ affinity and selectivity. The results showed that the new compounds have a good affinity for the A₃ receptor and in particular, the N⁶-methoxy-2-phenylethynyl-5'-N-methylcarboxamidoadenosine, with a K(i) at A₃ of 1.9 nM and a selectivity A₁/A₃ and A(₂A)/A₃ of 4,800- and 8,600-fold, respectively. Therefore, it is one of the most potent and selective agonists at the human A₃ adenosine receptor subtype reported so far. Furthermore, functional assays of inhibition of 10 μM forskolin-stimulated cAMP production via the adenosine A₃ receptor revealed that the new trisubstituted adenosine derivatives behave as full agonist of this receptor subtype. Docking analysis of these compounds was performed at a homology model of the human A₃ receptor based on the bovine rhodopsin crystal structure as template, and the results are in accordance with the biological data.
Tandem Diels—Alder/Fragmentation Approach to the Synthesis of Eleutherobin. (2003)

Abstract For Abstract see ChemInform Abstract in Full Text.
Design considerations for refractive solid immersion lens: Application to subsurface integrated circuit fault localization using laser induced techniques (2009)

With fast scaling and advancement of integrated circuit (IC) technology, circuitries have become smaller and denser. New materials and more sophisticated designs have evolved. These changes reduced the effectiveness of conventional laser induced fault localization techniques. Since IC fault localization is the most critical step in failure analysis, there are strong motivations to improve both spatial resolution and sensitivity of such systems to meet the new challenges from advanced technology. Refractive solid immersion lens (RSIL) is well known to enhance the laser spot size which directly affects resolution and sensitivity in back side fault localizations. In practice, it is difficult to operate RSIL at the ideal configurations to obtain the smallest spot resolution. It is necessary to understand the resolution performance at the other design focal planes. Besides resolution, there are also other factors that affect sensitivity in a RSIL enhanced system. This paper identifies and characterizes key RSIL design parameters to optimize RSIL performance on laser induced techniques. We report that the most efficient conditions are achieved close to aplanatic RSIL design to within 20-25 microm (for a 1 mm diameter lens), and the backing objective should be the minimum numerical aperture required for optimum resolution performance. The size of the mechanical clear aperture opening should be large enough (>80%) to exploit the advantage of aplanatic RSIL. RSIL is developed on a laser scanning optical microscope in this work, and a resolution of 0.3 microm (for a wavelength of 1340 nm) was achieved over a range of operating conditions. A quantitative resolution of 0.25 microm is achieved and a pitch structure of 0.4 microm is easily resolvable. Close to 15 times enhancement in laser induced signal is obtained.
Tonic Descending Facilitation from the Rostral Ventromedial Medulla Mediates Opioid-Induced Abnormal Pain and Antinociceptive Tolerance (2001)

Many clinical case reports have suggested that sustained opioid exposure can elicit unexpected, paradoxical pain. Here, we explore the possibility that (1) opioid-induced pain results from tonic activation of descending pain facilitation arising in the rostral ventromedial medulla (RVM) and (2) the presence of such pain manifests behaviorally as antinociceptive tolerance. Rats implanted subcutaneously with pellets or osmotic minipumps delivering morphine displayed time-related tactile allodynia and thermal hyperalgesia (i. e., opioid-induced "pain"); placebo pellets or saline minipumps did not change thresholds. Opioid-induced pain was observed while morphine delivery continued and while the rats were not in withdrawal. RVM lidocaine, or bilateral lesions of the dorsolateral funiculus (DLF), did not change response thresholds in placebo-pelleted rats but blocked opioid-induced pain. The intrathecal morphine antinociceptive dose-response curve (DRC) in morphine-pelleted rats was displaced to the right of that in placebo-pelleted rats, indicating antinociceptive "tolerance." RVM lidocaine or bilateral DLF lesion did not alter the intrathecal morphine DRC in placebo-pelleted rats but blocked the rightward displacement seen in morphine-pelleted animals. The subcutaneous morphine antinociceptive DRC in morphine-pelleted rats was displaced to the right of that in placebo-pelleted rats; this right shift was blocked by RVM lidocaine. The data show that (1) opioids elicit pain through tonic activation of bulbospinal facilitation from the RVM, (2) increased pain decreases spinal opioid antinociceptive potency, and (3) blockade of pain restores antinociceptive potency, revealing no change in antinociceptive signal transduction. These studies offer a mechanism for paradoxical opioid-induced pain and allow the development of approaches by which the loss of analgesic activity of opioids might be inhibited.
Photoluminescence Properties and Energy Transfer in Eu2+-Yb2+Codoped SrSi2O2N2Oxynitride Phosphor (2011)

Eu2+-Yb2+ codoped SrSi2O2N2 phosphors were prepared and their photoluminescence properties were investigated in comparison with the single Eu2+-doped and the single Yb2+-doped samples. Their photoluminescence properties were investigated as the factors of Yb2+ ion concentration, excitation wavelength, and temperature. Compared to the single Yb2+-doped sample, the Eu2+-Yb2+ codoped sample showed improved emission intensity, fluorescence lifetime, quantum efficiency, and thermal stability. An efficient energy transfer process from Eu2+ ions to Yb2+ ions was proposed to be responsible for the enhancement. The highest energy transfer efficiency was estimated to be 91.9%. A broadband yellow emission with full width at half maximum of ∼170 nm was also observed in the Eu2+-Yb2+ codoped sample, which could be assigned to the co-excitation of Eu2+ and Yb2+ ions. In view of too low quantum efficiency and the considerable thermal quenching of the emission at the operation temperature of high-power LED (>1 W/mm2), the SrSi2O2N2:Eu2+/Yb2+ phosphor might be only potential for low-power high Ra pc-white LED.
Safety and efficacy of carbon dioxide cryotherapy for treatment of neoplastic Barrett’s esophagus (2015)

Correction to: Safety and efficacy of carbon dioxide cryotherapy for treatment of neoplastic Barrett's esophagusEndoscopy 2015; 47(07): 582-591DOI: 10.1055/s-0034-1391734
Characterization of the surface immobilized synthetic heparin binding domain derived from human fibroblast growth factor‐2 and its effect on osteoblast differentiation (2007)

Fibroblast growth factor (FGF)-2 regulates a variety of cellular functions, such as proliferation and differentiation, by binding to cell surface FGF receptors (FGFRs) in the presence of heparin proteoglycans. FGF-2 is known as a heparin-binding growth factor, but the localization of the heparin binding site has not been fully investigated until now. We used two potential heparin binding domains of FGF-2, the residues 105-111 (F105, YKRSRYT) and 119-135 (F119, KRTGQYKLGSKTGPGQK). Peptides could be stably immobilized onto the surface of tissue culture plates. Using solid phase binding assays, we demonstrated that both peptides had higher binding affinity toward heparin compared with nonbinding control sequence. The biological significance of these sites was tested by cell attachment and osteoblast differentiation studies. Cell attachment to the peptides F105 and F119 increased in a dose-dependent manner. Heparin and heparinase treatments decreased cell adhesion to both F105 and F119. This demonstrates that both F105 and F119 interact with cell-surface heparan sulfate proteoglycans, suggesting that FGF-2 has two heparin binding sites. In addition, osteoblast differentiation, confirmed by ALPase activity and mineralization, was increased by surface immobilized peptide F105 and F119. Taken together, these heparin binding peptides could be applied as biological agents enhancing osteoblast differentiation as well as surface modification tools in the tissue regeneration area, especially for bone regeneration.
Status and prospects for SiC power MOSFETs (2002)

SiC electronic device technology has made rapid progress during the past decade. In this paper, we review the evolution of SiC power MOSFETs between 1992 and the present, discuss the current status of device development, identify the critical fabrication issues, and assess the prospects for continued progress and eventual commercialization.
3D MIMO Outdoor-to-Indoor Propagation Channel Measurement (2017)

The 3-D multiple-input multiple-output (3-D MIMO) systems have received great interest recently because of the spatial diversity advantage and capability for full-dimensional beamforming, making them promising candidates for practical realization of massive MIMO. In this paper, we present a low-cost test equipment (channel sounder) and post-processing algorithms suitable for investigating the 3-D MIMO channels as well as the results from a measurement campaign for obtaining elevation and azimuth characteristics in an outdoor-to-indoor (O2I) environment. Due to limitations in available antenna switches, our channel sounder consists of a hybrid switched/virtual cylindrical array with effectively 480 antenna elements at the base station. The virtual setup increased the overall MIMO measurement duration, thereby introducing phase drift errors in the measurements. Using reference antenna measurements, we estimate and correct for the phase errors during post-processing. We provide the elevation and azimuth angular spreads for the measurements done in an urban macro-cellular and urban micro-cellular environments, and study their dependence on the user equipment (UE) height. Based on the measurements done with UE placed on different floors, we study the feasibility of separating users in the elevation domain. The measured channel impulse responses are also used to study the channel hardening aspects of the massive MIMO and the optimality of the maximum ratio combining receiver.
Modeling Lift Hysteresis with a Modified Goman-Khrabrov Model on Pitching Airfoils (2015)

Wind tunnel experiments were conducted on two symmetric airfoils with different thickness ratios as a test of the ability of Goman-Khrabrov-type models to predict the lift coefficient history during pitching maneuvers. The primary difference between the two airfoils was that the thin airfoil had no hysteresis in its lift curve during quasi-steady maneuvers, but static hysteresis was observed with the thick airfoil over a range of 16 < α < 22. Both airfoils exhibited dynamic hysteresis in the lift coefficient when the wing was pitching. The existence of static hysteresis had a strong effect on the lift response during periodic pitching, and must be accounted for in the model. A modified version of the Goman-Khrabrov model was introduced that captured the static hysteresis behavior and the large-scale features of the dynamic hysteresis for the thick airfoil. Large-scale variations in the lift trajectory at different pitching frequencies are reproduced by the modified model, even when the thick airfoil is in a deep stall condition. Some deviations between model and experiment are observed at the highest angles of attack, which are attributed to the dynamic stall vortex and trailing edge vortex shedding.
Interactive Multimodal Volume Visualization for a Distributed Radiation- Treatment Planning Simulator (1994)

We describe the VISTAnet gigabit testbed&amp;apos;s visualization system, a parallel, interactive, multimodal renderer implemented on the Pixel-Planes 5 graphics engine. The system displays multiple superimposed data sets characterizing a 3D radiation treatment scenario. Its features are designed to facilitate comprehension of spatial relationships among geometrically complex anatomy and radiation dose structures. The algorithms and visualization options of this mature system are general and should be useful for other applications. The VISTAnet system is currently in clinical evaluation. 1.
Tumor Necrosis Factor-α Is Central to Acute Cigarette Smoke–induced Inflammation and Connective Tissue Breakdown (2002)

The role of tumor necrosis factor-alpha (TNF-alpha) as a mediator of cigarette smoke-induced disease is controversial. We exposed mice with knocked-out p55/p75 TNF-alpha receptors (TNF-alpha-RKO mice) to cigarette smoke and compared them with control mice. Two hours after smoke exposure, increases in gene expression of TNF-alpha, neutrophil chemoattractant, macrophage inflammatory protein-2, and macrophage chemoattractant, protein-1 were seen in control mice. By 6 hours, TNF-alpha, macrophage inflammatory protein-2, and macrophage chemoattractant protein-1 gene expression levels had returned to control values in control mice and stayed at control values through 24 hours. In TNF-alpha-RKO mice, no changes in gene expression of these mediators were seen at any time. At 24 hours, control mice demonstrated increases in lavage neutrophils, macrophages, desmosine (a measure of elastin breakdown), and hydroxyproline (a measure of collagen breakdown), whereas TNF-alpha-RKO mice did not. In separate experiments, pure strain 129 mice, which produce low levels of TNF-alpha, showed no inflammatory response to smoke at 24 hours or 7 days. We conclude that TNF-alpha is central to acute smoke-induced inflammation and resulting connective tissue breakdown, the precursor of emphysema. The findings support the idea that TNF-alpha promoter polymorphisms may be of importance in determining who develops smoke-induced chronic obstructive pulmonary disease.
Consequences of Folding a Water‐Soluble Polymer Around an Organocatalyst (2012)

Give 'em structure: The presence of structuring elements in polymers that were functionalized with catalytic units resulted in a new class of enzyme mimics, which are only active in the folded state (see picture). The conformationally adaptive hydrophobic environment that surrounds the catalytic site allows the very efficient catalysis of an aldol reaction in water with Michaelis–Menten kinetics.
Data from TTI-237: A Novel Microtubule-Active Compound with <i>In vivo</i> Antitumor Activity (2023)

&lt;div&gt;Abstract&lt;p&gt;5-Chloro-6-[2,6-difluoro-4-[3-(methylamino)propoxy]phenyl]-&lt;i&gt;N&lt;/i&gt;-[(1&lt;i&gt;S&lt;/i&gt;)-2,2,2-trifluoro-1-methylethyl]-[1,2,4]triazolo[1,5-&lt;i&gt;a&lt;/i&gt;]pyrimidin-7-amine butanedioate (TTI-237) is a microtubule-active compound of novel structure and function. Structurally, it is one of a class of compounds, triazolo[1,5a]pyrimidines, previously not known to bind to tubulin. Functionally, TTI-237 inhibited the binding of [&lt;sup&gt;3&lt;/sup&gt;H]vinblastine to tubulin, but it caused a marked increase in turbidity development that more closely resembled the effect observed with docetaxel than that observed with vincristine. The morphologic character of the presumptive polymer is unknown at present. When applied to cultured human tumor cells at concentrations near its IC&lt;sub&gt;50&lt;/sub&gt; value for cytotoxicity (34 nmol/L), TTI-237 induced multiple spindle poles and multinuclear cells, as did paclitaxel, but not vincristine or colchicine. Flow cytometry experiments revealed that, at low concentrations (20–40 nmol/L), TTI-237 produced sub-G&lt;sub&gt;1&lt;/sub&gt; nuclei and, at concentrations above 50 nmol/L, it caused a strong G&lt;sub&gt;2&lt;/sub&gt;-M block. The compound was a weak substrate of multidrug resistance 1 (multidrug resistance transporter or P-glycoprotein). In a cell line expressing a high level of P-glycoprotein, the IC&lt;sub&gt;50&lt;/sub&gt; of TTI-237 increased 25-fold whereas those of paclitaxel and vincristine increased 806-fold and 925-fold, respectively. TTI-237 was not recognized by the MRP or MXR transporters. TTI-237 was active &lt;i&gt;in vivo&lt;/i&gt; in several nude mouse xenograft models of human cancer, including LoVo human colon carcinoma and U87-MG human glioblastoma, when dosed i.v. or p.o. Thus, TTI-237 has a set of properties that distinguish it from other classes of microtubule-active compounds. [Cancer Res 2008;68(7):2292–300]&lt;/p&gt;&lt;/div&gt;
Utilization of Feline ELISPOT for Mapping Vaccine Epitopes (2011)

A commercial feline immunodeficiency virus (FIV) vaccine consisting of inactivated dual-subtype viruses was released in the USA in 2002 and released subsequently over the next 6 years in Canada, Australia, New Zealand, and Japan. Based on the genetic, morphologic, and biochemical similarities between FIV and human immunodeficiency virus-1 (HIV-1), FIV infection of domestic cats is being used as a small animal model of HIV/AIDS vaccine. Studies on prototype and commercial FIV vaccines provide new insights to the types of immunity and the vaccine epitopes required for an effective human HIV-1 vaccine. ELISPOT assays to detect cytokines, chemokines, and cytolytic mediators are widely used to measure the magnitude and the types of cellular immunity produced by vaccination. Moreover, such approach has identified regions on both HIV-1 and FIV proteins that induce robust antiviral cellular immunity in infected hosts. Using the same strategy, cats immunized with prototype and commercial FIV vaccines are being analyzed by feline interferon-γ and IL-2 ELISPOT systems to identify the vaccine epitope repertoire for prophylaxis.
Controlling H+ vs CO2 Reduction Selectivity on Pb Electrodes (2014)

Nanocrystalline Pb films prepared by reducing PbO2 precursors have up to 700-fold lower H+ reduction activity than polycrystalline Pb foil electrodes but maintain the ability to reduce CO2. As a result, these “oxide-derived” Pb (OD–Pb) electrodes have higher Faradaic efficiency for CO2 reduction to HCO2– in aqueous solutions with almost no competitive H+ reduction. Even with very low CO2 concentrations in N2-saturated NaHCO3 solution, OD–Pb converts CO2 derived from HCO3– decomposition to HCO2– with almost quantitative Faradaic efficiency while Pb foil has less than 10% efficiency. Electrokinetic data suggest that the difference in selectivity between the two electrodes is caused by a difference in the coverage of a surface layer—likely a metastable Pb oxide—that is passivating for H+ reduction but active for CO2 reduction.
TERM INFANT FORMULA SUPPLEMENTED WITH HUMAN MILK OLIGOSACCHARIDES (2'FUCOSYLLACTOSE AND LACTO‐NEOTETRAOSE) SHIFTS STOOM MICROBIOTA AND METABOLIC SIGNATURES CLOSER TO THAT OF BREASTFED INFANTS. (2016)

Human milk oligosaccharides (HMOs) are thought to influence early intestinal microbiota establishment and may thereby provide benefits to formula‐fed infants. We evaluated the effect of infant formula with 2 HMOs (2'Fucosyllactose [2'FL] and Lacto‐N‐ neo tetraose [LNnT]) on the establishment of the intestinal microbiota in infants ( ClinicalTrials.gov NCT01715246). Healthy term infants, who were 0–14 days old at enrolment, were randomized to intact protein cow's milk‐based infant formula (Control, n 87) or the same formula with 1.0 g/L 2'FL and 0.5 g/L LNnT (Test, n 88). Fully breastfed infants were also studied as a reference group ( n 38). Stool samples were collected at 3 months of age for microbiota assessment using 16S rRNA gene sequencing and metagenomics; metabolic signature in stool was assessed using proton NMR. The global average microbial composition profile was established for infants from whom stool samples were available and who adhered to the protocol. A similar formula‐fed pattern for Control ( n 65) and Test ( n 58) was seen at the genus level, although Test appeared closer to breastfed ( n 34) than Control. Calculation of microbial alpha diversity and comparison of the global microbiota composition using random permutations of the redundancy analysis (RDA) confirmed that Test was different from Control at genus level (p &lt; 0.001) and closer to the breastfed group. By statistical analyses we identified several taxa differentially present in Control and Test. These were Bifidobacterium (p = 0.01), Escherichia (p = 0.008), unclassified Coprobacillaceae (p = 0.01), unclassified Peptostreptococcaceae (p = 0.026), Dorea (p = 0.033), and Megamonas (p = 0.035). Correction for False Discovery Rate confirmed the first three taxa. Main discriminants between Test and Control by random forest analysis were Bifidobacterium , Escherichia and Peptostreptococcaceae . Clinically relevant pathogens were very rarely found; however, Clostridium difficile toxin A/B was detected in 14% of Test and 26% Control (OR 0.47, CI 0.17–1.27, p = 0.15). Multivariate stool metabolite analysis identified influential metabolites that discriminate between Test, Control and breastfed group. These were the amino acids phenylalanine, isoleucine, tyrosine, fecal organic acids and fucosylated compounds. Globally, the metabolic signatures observed in Test were more similar to those observed in stool of breastfed infants than Control. The observed profiles may indicate reduced protein fermentation in Test compared to Control. Together the stool microbiota and metabolic signature show that the addition of 2'FL and LNnT to a starter infant formula shift the stool microbiota towards that observed in breastfed infants, both in composition and function. Further studies are warranted to evaluate whether such a shift in gut ecology towards the breastfed standard leads to health benefits.