gebhart/patrepeval huggingface dataset:
Synthesis and Anion‐Binding Properties of Novel Redox‐Active Calixarene Receptors (2008)

Abstract A novel synthetic approach towards redox‐active calixarene‐based receptors is described in which ferrocene fragments were introduced at the lower rim through anion‐binding urea or amide connections. These derivatives were prepared in one pot by treating an amine‐containing calixarene with ferrocenecarboxylic acid in the presence of diphenylphosphoryl azide and diisopropylethylamine. This method allows a convergent approach to these receptors and is readily adaptable to the introduction of other urea substituents. The anion‐binding properties of these artificial receptors have been revealed by NMR spectroscopy and thoroughly investigated by electrochemical methods. We have assessed the importance of the urea–phosphate bonds in the observed electrochemical response by studying receptors in which the ferrocene reporters and binding fragments are closely associated or fully disconnected through a long alkyl chain. The experimental results clearly show the utmost importance of ion‐pairing effects in the electrochemical recognition process, which account for most of the transduction signal in organic apolar media. (© Wiley‐VCH Verlag GmbH &amp; Co. KGaA, 69451 Weinheim, Germany, 2008)
Superconductivity and the Metal-Nonmetal Transition in Hg-Xe Films (1979)

The electrical conductivities and transition temperatures of films consisting of random mixtures of Hg and Xe condensed onto substrates held at 4.2 K have been measured. A metal-nonmetal transition in which the temperature coefficient of resistance changes from positive to negative has been found near a volume fraction close to that expected for random percolation. This transition is accompanied by a substantial drop in the superconducting transition temperature which is measured resistively.
Computer‐aided navigation for arthroscopic hip surgery using encoder linkages for position tracking (2006)

This navigation system for arthroscopic hip surgery can be used as a tool to address the challenges of joint navigation and portal placement in arthroscopic hip surgery by visually supplementing the limiting view from the arthroscope. The introduction of a tracking linkage shows significant potential as an alternative to other tracking systems. Positive feedback about the completed demo system was obtained from surgeons who perform arthroscopic procedures.
A Method for the Preparation of High-Molecular-Weight DNA from Marine and Freshwater Triclads (Platyhelminthes, Turbellaria) (1990)

Although the last decade has seen much activity devoted to the phylogeny of the Platyhelminthes, such activity has relied in the main on traditional anatomical, ultrastructural, and developmental data. Extension of these studies to the molecular level has been impeded by the lack of a reliable method for the isolation of DNA from these organisms, especially marine triclads whose DNA is particularly difficult to isolate using methods currently used with other eukaryotic or prokaryotic organisms. We report here the details of a method that results in the rapid isolation of relatively pure DNA in good yields from small amounts of material. The method involves the treatment of the animals with high concentrations of NaDodSO4 followed by phenol extraction, resulting in a product that is an excellent substrate for restriction endonuclease digestion and Southern blotting.
Standardised terminology for the description and analysis of equine locomotion (1984)

Terminology for the analysis of equine locomotion is reviewed and the most appropriate terms selected for use by research workers in this field. Each cycle of limb movement comprises a stance phase, when the hoof is in contact with the ground, alternating with a swing phase. The stance phase is subdivided at the mid-stance position into an initial decelerative phase followed by a propulsive phase. When the stance phases of different limbs occur concurrently, the term overlap refers to the duration of simultaneous ground contact. Single support is the term used to describe the phase when the limb is in its stance phase unaided by any other limb. A gait consists of a limb coordination pattern repeated at each stride. The start and finish of the stride must be designated as a prerequisite to the determination of stride length, stride duration and stride frequency. In asymmetrical gaits, such as the gallop, the stride as a whole will have a stride stance phase, when one or more limbs are in contact with the ground, and a suspension phase. In symmetrical gaits, such as the trot and pace, the stride consists of left and right stance phases and suspension phases. Advanced placement and advanced lift off measure the time between ground placement and lift off respectively of consecutive limbs. The line of motion indicates the progressive movement of the centre of gravity in the X-Y plane. Measurements in th Y-Z plane, such as line gait and overcrossing, describe the ground placement of the hooves relative to the line of motion. Diagonal width is the distance between diagonal limb pairs in this plane.
Microstructure and morphology of self‐assembling multiblock poly(ethylene‐1‐butene)‐n copolymers in solution studied by wide‐Q small‐angle neutron scattering and microscopy (2010)

Abstract Multiblock ethylene‐1‐butene copolymers (PEB‐ n ) with graded ethylene content (where n is the number of ethyl branches per 100 backbone carbons) represent efficient cold filter plugging point (CFPP) depressants for crude oils and middle distillates. The aggregation behavior and the interaction with wax molecules of a tetrablock PEB‐2.6/PEB‐6.0/PEB‐10.9/PEB‐13.2 and triblock PEB‐6.5/PEB‐8.9/PEB‐10.1 copolymers in decane solutions were investigated over a wide temperature range by combining different small‐angle neutron scattering techniques and optical microscopy. The experimental results revealed in the decrease of temperature formation and evolution of multisized structural levels showing a hierarchical organization on the length scale from 1 nm up to 10 μm. One‐dimensional polymer aggregates arising as initial structures associate and branch that lead to the occurrence of complex macroaggregates with diffusive interfaces and sizes of several microns. The one‐dimensional copolymer structure shows longitudinal density modulation and micellar‐like substructures in neat polymer solutions. When wax is added, this structure becomes more homogeneous in decrease of temperature as a consequence of the cocrystallization of wax and copolymer. The wax crystallization in board‐like objects of much smaller size than required by the CFPP criterion of oil and refinery industry (filter mesh size of 45 μm) is templated and controlled by the assembling features of the crystalline–amorphous PEB‐ n multiblock copolymers. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011
Surface Chemistry of III-V Semiconductors After Wet Etching with HCl and H2O2 (2015)

GaAs(100) was immersed in water and aqueous mixtures of isopropyl alcohol, ethylene glycol, acetic acid, glycolic acid, tartaric acid, and HCl with and without the addition of H 2 O 2 to understand the etching mechanism. The surface composition after etching was characterized using x-ray photoelectron spectroscopy (XPS) and temperature programmed desorption (TPD). Ga and As oxides with high oxidation states dissolve in water, but acids are needed to remove the oxides with low oxidation states. H 2 O 2 oxidized the bulk substrate, and only the acids that have pK a values lower than 4 supported etching. After etching with HCl, the surface is terminated by arsenic chloride (As-Cl).
Design considerations and experimental analysis of high-voltage SiC Schottky barrier rectifiers (1998)

Practical design of high-voltage SiC Schottky rectifiers requires an understanding of the device physics that affect the key performance parameters. Forward characteristics of SiC Schottky rectifiers follow thermionic emission theory and are relatively well understood. However, the reverse characteristics are not well understood and have not been experimentally investigated in-depth. In this paper we report the analysis and experimental results of both the forward and reverse characteristics of high-voltage SiC Schottky rectifiers. Ti and Ni Schottky rectifiers with boron implant edge termination were fabricated on n-type 4H SiC samples. Ni Schottky rectifiers fabricated on a 13-/spl mu/m thick 3.5/spl times/10/sup 15/ cm/sup -3/ epilayer have a current density of 100 A/cm/sup 2/ at approximately 2 V forward bias and a reverse leakage current density of less than 0.1 A/cm/sup 2/ at a reverse bias of 1720 V. The reverse leakage current is observed to depend on device area, Schottky barrier height, electric field at the metal-semiconductor interface, and temperature (a decreasing temperature dependence with increasing reverse bias). In addition. the reverse leakage current magnitude is larger and the electric field dependence is stronger than predicted by thermionic emission and image-force barrier height lowering. This suggests the reverse leakage current is due to a combination of thermionic field emission and field emission.
Estimating and Fusing Quality Factors for Iris Biometric Images (2010)

Iris recognition, the ability to recognize and distinguish individuals by their iris pattern, is one of the most reliable biometrics in terms of recognition and identification performance. However, the performance of these systems is affected by poor-quality imaging. In this paper, we extend iris quality assessment research by analyzing the effect of various quality factors such as defocus blur, off-angle, occlusion/specular reflection, lighting, and iris resolution on the performance of a traditional iris recognition system. We further design a fully automated iris image quality evaluation block that estimates defocus blur, motion blur, off-angle, occlusion, lighting, specular reflection, and pixel counts. First, each factor is estimated individually, and then, the second step fuses the estimated factors by using a Dempster-Shafer theory approach to evidential reasoning. The designed block is evaluated on three data sets: Institute of Automation, Chinese Academy of Sciences (CASIA) 3.0 interval subset, West Virginia University (WVU) non-ideal iris, and Iris Challenge Evaluation (ICE) 1.0 dataset made available by National Institute for Standards and Technology (NIST). Considerable improvement in recognition performance is demonstrated when removing poor-quality images selected by our quality metric. The upper bound on computational complexity required to evaluate the quality of a single image is O(n <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> log n).
Expression of the embryonal isoform (0N/3R) of the microtubule‐associated protein tau in the adult rat central nervous system (2010)

Tau is a microtubule-associated protein expressed predominantly in neurons. The transcript of the tau gene is alternatively spliced. Resulting isoforms contain three or four microtubule-binding repeats. The shortest tau isoform contains only three repeats (3R) and is expressed at birth. Previous data on rodents suggested that this isoform is no longer expressed during adulthood. It is replaced by tau isoforms containing four repeats (4R). The adult 4R tau isoforms bind to microtubules with higher affinity than 3R tau isoforms. Therefore, this isoform switch may reflect a need for more dynamic microtubules during development. Recently, we observed in rats that the 3R tau isoform is transiently expressed in adult neurogenesis. Subsequently, we performed an immunohistochemical labeling of the 3R tau isoform on serial sections of the adult rat brain. Interestingly, the 3R tau isoform is not only expressed in neuronal precursor cells. It is also present in mature neurons of the olfactory bulb, magnocellular neurosecretory system, posterolateral hypothalamus, locus coeruleus, raphe nucleus, solitary nucleus, medial septum and diagonal band, olfactory tuberculus, and piriform/olfactory cortex. This expression pattern is similar to that observed for the polysialylated form of the neuronal cell adhesion molecule (PSA-NCAM) and the microtubule-associated proteins doublecortin and collapsin response mediating protein (CRMP-4/TUC-4/Ulip-1), which are also highly expressed during early development. The retention of a juvenile phenotype in some neurons might be associated with a functionally significant neuronal plasticity.
Sulfide Modification of Dye-Sensitized Solar Cell Gold Cathodes for Use with Cobalt Polypyridyl Mediators (2014)

[Co(bpy)3]2+/3+-type complexes have emerged as promising alternatives to the traditional I–/I3– electrolyte used in dye-sensitized solar cells (DSSCs). One of the many advantages these complexes exhibit is their ability to undergo reduction on Au cathodes rather than the more expensive Pt. However, in our experience irreproducibility of fabricated Au cathodes has been a longstanding issue due to variations in charge-transfer resistance (RCT) for the Co2+/3+ couple. These variations manifest themselves as poor fill factors in the current–voltage measurements. In an effort to increase electronic coupling between the Co complex and the Au surface (and thereby reduce RCT), a simple surface modification with sulfide ion has been developed. XPS measurements indicate the modification is stable after exposure to mediator solution. Cyclic voltammetry shows a drastic increase in reversibility for the Co2+/3+ electrochemistry, especially under typical DSSC mediator conditions. A commensurate enhancement in the fill factor is observed in subsequent J–V measurements. The results provide a straightforward method of yielding more reproducible Au cathodes to be used in combination with [Co(bpy)3]2+/3+-type mediators.
Volume array with optical feeds (2002)

Volumetric phased arrays offer full spherical coverage with phase-only control. To overcome problems of feed obstruction limitations, we report an array in which transmit power and signal are delivered to each element on the fibre.
Post-Silicon Validation in the SoC Era: A Tutorial Introduction (2017)

Editor's note: Post-silicon validation is a complex and critical component of a modern system-on-chip (SoC) design verification. It includes a large number of inter-related activities each with its own nuance and subtleties, requires extensive planning, and spans the entire system design lifecycle. This article provides a comprehensive high-level overview of the various facets of post-silicon validation, and includes industrial case studies illustrating their real-life application.
The Emerging Clinical Importance of Non-O157 Shiga Toxin--Producing Escherichia coli (2006)

In 1982, hemorrhagic colitis and hemolytic-uremic syndrome were linked to infection with Escherichia coli O157:H7, a serotype now classified as Shiga toxin-producing E. coli (STEC). Thereafter, hemorrhagic colitis and hemolytic-uremic syndrome associated with non-O157 STEC serogroups were reported, with the frequency of non-O157 STEC illness rivaling that of O157:H7 in certain geographic regions. In the United States, non-O157 E. coli may account for up to 20%-50% of all STEC infections. A high index of suspicion, paired with options to test for non-O157 STEC infection, are necessary for early recognition and appropriate treatment of these infections. Supportive care without the use of antibiotics is currently considered to be optimal treatment for all STEC infections. This commentary provides a perspective on the non-O157 STEC as human pathogens, how and when the clinician should approach the diagnosis of these organisms, and the challenges ahead.
Hierarchical pipelining and folding of QRD-RLS adaptive filters (2002)

A novel approach for hierarchically pipelining and folding the CORDIC-based systolic triangular array of a QRD-RLS filter to a small fixed size array is presented. With the annihilation-reordering look-ahead transformation, the iteration bound of a QRD-RLS filter can be reduced proportional to the look-ahead level. This paper presents, for the first time, how to pipeline and fold such a look-ahead transformed QRD-RLS array in a hierarchical way. Compared to the previously published mapping algorithms, this approach has low complexity and can result in a physical array of any size. Therefore, it is of great significance for ASIC chip designs and high-level synthesis. Besides, it is shown how a combination of look-ahead, pipelining and folding transformations can lead to an increase in throughput, a large reduction in area or a great saving in power consumption.
The chemistry of bread making: The role of salt to ensure optimal functionality of its constituents (2016)

Large consumptions of dietary sodium have been shown to lead to hypertension, one of the main causative factors in cardiovascular disease. Bread (and other cereal products) accounts for ~30% of the overall sodium intake in our diet; therefore, industry has been developing strategies to significantly reduce its usage. However, at reduced sodium levels, dough handling can be affected due to sticky dough phenomena creating major processing issues and a poor quality final product. It is hypothesized that the formation of a strong gluten network plays a crucial role in developing nonsticky dough, a process that is strengthened in the presence of NaCl. However, at low NaCl levels, a weaker gluten network forms resulting in the prevalence of other wheat flours’ constituents impact on water mobility within the dough to contribute to the stickiness phenomenon. This review discusses the underlying mechanisms that can influence the formation of sticky dough within a low sodium environment and discusses strategies used to help circumvent them.
Oligodendrocyte Progenitors Reversibly Exit the Cell Cycle and Give Rise to Astrocytes in Response to Interferon-γ (2011)

Oligodendrocyte-type 2 astrocyte progenitor cells (O-2A/OPCs) populate the CNS and generate oligodendrocytes and astrocytes in vitro and in vivo. Understanding how O-2A/OPCs respond to their environment is crucial to understanding how these cells function in the CNS and how to best promote their therapeutic proliferation and differentiation. We show that interferon-γ (IFN-γ) was not toxic to highly purified perinatal or adult rat O-2A/OPCs. IFN-γ treatment led to downregulation of PDGFR-α (platelet-derived growth factor receptor-α) and Ki-67 and decreased self-renewal in clonal populations. IFN-γ also significantly increased the proportion of cells in the G(0)/G(1) phase of the cell cycle, decreased BrdU (5-bromo-2'-deoxyuridine) incorporation, and led to increased expression of the cell cycle inhibitors Rb and p27(kip1). Although p27(kip1) expression was not necessary for IFN-γ-mediated quiescence, its upstream regulator IRF-1 was required. The quiescent state of O-2A/OPCs caused by IFN-γ was reversible as the withdrawal of IFN-γ allowed O-2A/OPCs to appropriately respond to both proliferation and differentiation signals. Differentiation into oligodendrocytes induced by either thyroid hormone or CNTF was also abrogated by IFN-γ. This inhibition was specific to the oligodendrocyte pathway, as O-2A/OPC differentiation into astrocytes was not inhibited. IFN-γ alone also led to the generation of GFAP-positive astrocytes in a subset of O-2A/OPCs. Together, these results demonstrate a reversible inhibitory effect of IFN-γ on O-2A/OPC proliferation with a concomitant generation of astrocytes. We propose that neuroinflammation involving increased IFN-γ can reduce progenitor numbers and inhibit differentiation, which has significant clinical relevance for injury repair, but may also contribute to the generation of astrocytes.
Coordination-Driven Self-Assembly of M3L2 Trigonal Cages from Preorganized Metalloligands Incorporating Octahedral Metal Centers and Fluorescent Detection of Nitroaromatics (2011)

The design and preparation of novel M(3)L(2) trigonal cages via the coordination-driven self-assembly of preorganized metalloligands containing octahedral aluminum(III), gallium(III), or ruthenium(II) centers is described. When tritopic or dinuclear linear metalloligands and appropriate complementary subunits are employed, M(3)L(2) trigonal-bipyramidal and trigonal-prismatic cages are self-assembled under mild conditions. These three-dimensional cages were characterized with multinuclear NMR spectroscopy ((1)H and (31)P) and high-resolution electrospray ionization mass spectrometry. The structure of one such trigonal-prismatic cage, self-assembled from an arene ruthenium metalloligand, was confirmed via single-crystal X-ray crystallography. The fluorescent nature of these prisms, due to the presence of their electron-rich ethynyl functionalities, prompted photophysical studies, which revealed that electron-deficient nitroaromatics are effective quenchers of the cages' emission. Excited-state charge transfer from the prisms to the nitroaromatic substrates can be used as the basis for the development of selective and discriminatory turn-off fluorescent sensors for nitroaromatics.
Luteal phase progesterone excretion in ovulatory women with polycystic ovaries (2002)

Women with PCO did not have more variation in cycle length than fertile women with normal ovaries, but there were significantly lower levels of progesterone in the early luteal phase. This may contribute to the delay in conception in these patients.
A low-cost, high-field-strength magnetic resonance imaging–compatible actuator (2015)

To perform minimally invasive surgical interventions with the aid of robotic systems within a magnetic resonance imaging scanner offers significant advantages compared to conventional surgery. However, despite the numerous exciting potential applications of this technology, the introduction of magnetic resonance imaging-compatible robotics has been hampered by safety, reliability and cost concerns: the robots should not be attracted by the strong magnetic field of the scanner and should operate reliably in the field without causing distortion to the scan data. Development of non-conventional sensors and/or actuators is thus required to meet these strict operational and safety requirements. These demands commonly result in expensive actuators, which mean that cost effectiveness remains a major challenge for such robotic systems. This work presents a low-cost, high-field-strength magnetic resonance imaging-compatible actuator: a pneumatic stepper motor which is controllable in open loop or closed loop, along with a rotary encoder, both fully manufactured in plastic, which are shown to perform reliably via a set of in vitro trials while generating negligible artifacts when imaged within a standard clinical scanner.
Challenges in deposition of wide band gap copper indium aluminum gallium selenide (CIAGS) thin films for tandem solar cells (2014)

Copper indium gallium diselenide (CIGS) based solar cells have shown efficiencies > 20% on the lab scale and are already in commercial production. Even though the optimal band gap of 1.6eV to 1.7eV can be achieved by increasing the Ga content, these solar cells show a maximum efficiency at ~1.3eV and any further increase in the Ga concentration and band gap results in lower efficiencies due to bulk and interfacial traps. This also prevents the use of wide band gap CIGS layer as a top cell for harvesting the solar cell spectrum in a tandem cell configuration. This paper reports the manufacturing challenges on the production of wide band gap aluminum doped CIGS layers (CIAGS) and devices fabricated using this material. We have fabricated 11.3% efficient solar cells using the CIAGS absorber layers.