gebhart/patrepeval huggingface dataset:
Multi-Fractal Hierarchy of Single-Walled Carbon Nanotube Hydrophobic Coatings (2015)

A hierarchical structure is an assembly with a multi-scale morphology and with a large and accessible surface area. Recent advances in nanomaterial science have made increasingly possible the design of hierarchical surfaces with specific and tunable properties. Here, we report the fractal analysis of hierarchical single-walled carbon nanotube (SWCNT) films realized by a simple, rapid, reproducible, and inexpensive filtration process from an aqueous dispersion, then deposited by drytransfer printing method on several substrates, at room temperature. Furthermore, by varying the thickness of carbon nanotube random networks, it is possible tailoring their wettability due to capillary phenomena in the porous films. Moreover, in order to describe the wetting properties of such surfaces, we introduce a two-dimensional extension of the Wenzel-Cassie-Baxter theory. The hierarchical surface roughness of SWCNT coatings coupled with their exceptional and tunable optical and electrical properties provide an ideal hydrophobic composite surface for a new class of optoelectronic and nanofluidic devices.
5-GHz band SiGe HBT linear power amplifier IC with novel CMOS active bias circuit for WLAN applications (2014)

This paper presents a highly linear 5-GHz band power amplifier IC with integrated novel CMOS active bias circuit in SiGe BiCMOS technology for wireless LAN applications. The power amplifier IC consists of three-stage amplifier, the CMOS active bias circuit for linearizing SiGe HBT and all matching circuits. The power amplifier IC has exhibited a measured output power of 17.0 dBm, an EVM of 0.9 % and a dc current consumption of 284 mA under 54 Mbps OFDM signal at 5.4 GHz.
Characterization of Thin Films of Conjugated Polymer (BEHP-PPV) -co-(MEH-PPV) for OLEDs Aplication (2006)

(BEHP-PPV)-co-(MEH-PPV) is a highly soluble copolymer, more stable to photo-oxidation process than other phenyl-substituted PPV derivatives, which is appropriate to use as the active layer in organic-based light emitting devices (OLEDs). In this paper we present optical properties such as the refractive index, the extinction coefficient, and the optical gap between HOMO and LUMO levels of these polymer films, determined by absorption and photoluminescence measurements. We also show the J-V characteristics of single-layer diode structures and their relation with the injecting electrodes. It was also studied etch properties of the film looking for compatibility with photolithographic processes
Activated mast cells produce interleukin 13. (1995)

When mast cells are activated through their immunoglobulin (Ig)E receptors, release of low molecular weight mediators like histamine is followed by secretion of multiple cytokines, including interleukin (IL)-3, IL-4, IL-5, and granulocyte/macrophage colony-stimulating factor. Here we report that stimulated mast cells also synthesize IL-13 mRNA and protein; secretion of this cytokine may be of particular importance because of its ability to stimulate IgE expression. IL-13 transcripts detected by a semiquantitative reverse transcriptase-mediated polymerase chain reaction assay were induced within 30 min after stimulation of mast cells by dinitrophenyl plus monoclonal IgE anti-dinitrophenyl, and peaked at about 1 h. Within 3 h of IgE stimulation, secreted IL-13 bioactivity, estimated by proliferation of an IL-13-dependent cell line, reached levels equivalent to 1-2 ng/ml of IL-13. When added to human B lymphocytes, the mast cell-derived IL-13 activity (like bone fide IL-13) induced Ig C epsilon transcripts, DNA recombination characteristic of the isotype switch to C epsilon, and the secretion of IgE protein. These results suggest a model of local positive feedback interactions between mast cells and B cells, which could play a role in the pathogenesis of atopy.
Real-time measurement of flow rate in microfluidic devices using a cantilever-based optofluidic sensor (2013)

Real-time and accurate measurement of flow rate is an important reqirement in lab on a chip (LOC) and micro total analysis system (μTAS) applications. In this paper, we present an experimental and numerical investigation of a cantilever-based optofluidic flow sensor for this purpose. Two sensors with thin and thick cantilevers were fabricated by engraving a 2D pattern of cantilever/base on two polymethylmethacrylate (PMMA) slabs using a CO2 laser system and then casting a 2D pattern with polydimethylsiloxane (PDMS). The basic working principle of the sensor is the fringe shift of the Fabry-Pérot (FP) spectrum due to a changing flow rate. A Finite Element Method (FEM) is used to solve the three dimensional (3D) Navier-Stokes and structural deformation equations to simulate the pressure distribution, velocity and cantilever deflection results of the flow in the channel. The experimental results show that the thin and thick cantilevers have a minimum detectable flow change of 1.3 and 4 (μL min(-1)) respectively. In addition, a comparison of the numerical and experimental deflection of the cantilever has been done to obtain the effective Young's modulus of the thin and thick PDMS cantilevers.
Compensation of friction effects in gyro-stabilized motion platforms (2015)

A frequent problem encountered in the stabilization of gyro-stabilized motion platforms is the disturbance rejection associated with moving components. Due to relative motion of adjacent components, friction is induced by the destabilizing force from the base motion to the stabilized object, degrading its motion accuracy. Hence, a compensation of frictional effects is necessary in order to obtain a highly precise stabilization performance. In this paper, applications of both single-state disturbance observer and well-known LuGre friction model on gyro-stabilized motion platforms is presented to compensate for friction. The compensation techniques are described for a generalized control system and simplified for a specific case. The success of these techniques is validated via experiments and simulations by constructing a block diagram of the system stabilization loop. An added disturbance observer yields a similar improvement in the stabilization performance as the LuGre friction model does at low frequencies. However, the performance of disturbance observer degrades as the frequency of disturbances increases although it still improves the overall stabilization performance of the system.
On the Hydrogen Passivation of Highly Doped Emitters (2009)

This work focuses on the passivation of highly doped silicon surfaces. We propose here to bring more knowledge on the emitter passivation by hydrogen during the thermal annealing of standard silicon nitride ARC layer. Silicon wafers were phosphorus-diffused, and the surfaces were subsequently covered by SiNx:H. Different rapid thermal annealing processes, varying in time and temperature, were then applied. Annealing time and temperature variations led to an optimal lifetime value. We also noticed a sheet resistance variation for different annealing parameters, although emitter had the same doping profile before annealing. This can be explained by the dopant deactivation due to the hydrogen release during annealing, leading to an effective doping decrease. Comparing the sheet resistance and the lifetime results, we found that the optimum passivation was correlated with the higher sheet resistance. Another important aspect to consider is therefore the contact resistance between emitter and metal. As hydrogen turns phosphorus inactive electrically, it can also lead to a contact resistance increase. TLM measurements allowed us to observe the evolution of the contact resistance, depending on firing temperature
Inter-species transplantation of gut microbiota from human to pigs (2007)

Direct research on gut microbiota for understanding its role as 'an important organ' in human individuals is difficult owing to its vast diversity and host specificity as well as ethical concerns. Transplantation of human gut microbiota into surrogate hosts can significantly facilitate the research of human gut ecology, metabolism and immunity but rodents-based model provides results with low relevance to humans. A new human flora-associated (HFA) piglet model was hereby established taking advantage of the high similarity between pigs and humans with respect to the anatomy, physiology and metabolism of the digestive system. Piglets were delivered via cesarean section into a SPF-level barrier system and were inoculated orally with a whole fecal suspension from one healthy 10-year-old boy. The establishment and composition of the intestinal microbiota of the HFA piglets were analyzed and compared with that of the human donor using enterobacterial repetitive intergenic consensus sequence-PCR fingerprinting-based community DNA hybridization, group-specific PCR-temperature gradient gel electrophoresis and real-time PCR. Molecular profiling demonstrated that transplantation of gut microbiota from a human to germfree piglets produced a donor-like microbial community with minimal individual variation. And the microbial succession with aging of those ex-germfree piglets was also similar to that observed in humans. This HFA model provides a significantly improved system for research on gut ecology in human metabolism, nutrition and drug discovery.
Development of Potent Serotonin-3 (5-HT3) Receptor Antagonists. II. Structure-Activity Relationships of N-(1-Benzyl-4-methylhexahydro-lH-1,4-diazepin-6-yl)carboxamides. (1995)

Our studies on 4-amino-5-chloro-2-ethoxybenzamides led to the discovery that the N-(1,4-dimethylhexahydro-1H-1,4-diazepin-6-yl)benzamide 9 and the 1-benzyl-4-methylhexahydro-1H-1,4-diazepine analogue 10 are potent serotonin-3 (5-HT3) receptor antagonists. Structure-activity relationship (SAR) studies on the influence of the aromatic nucleus of 9 and 10 upon inhibition of the von Bezold-Jarisch reflex in rats are described. Heteroaromatic rings such as pyrrole, thiophene, furan, pyridine, pyridazine, 1,2-benzisoxazole, indole, quinoline, and isoquinoline rings showed weak 5-HT3 receptor antagonistic activity. Within this series, use of the 1H-indazole ring as an aromatic moiety led to a substantial increase of the activity; the 1H-indazolylcarboxamides 54, 57, 97, and 102 showed potent 5-HT3 receptor antagonistic activity. The optimal compound identified via extensive SAR studies was N-(1-benzyl-4-methylhexahydro-1H-1,4-diazepin-6-yl)-1H-indaz ole-3- carboxamide (54), whose effect was superior to that of the corresponding benzamide 10 and essentially equipotent to those of ondanbsetron (1) and granisetron (4).
Purification and properties of protoporphyrinogen oxidase from the yeast Saccharomyces cerevisiae. Mitochondrial location and evidence for a precursor form of the protein. (1994)

Protoporphyrinogen oxidase, the molecular target of diphenylether-type herbicides, was purified to homogeneity from yeast mitochondrial membranes and found to be a 55-kDa polypeptide with a pI of 8.5 and a specific activity of 40,000 nmol of protoporphyrin/h/mg of protein at 30 degrees C. The Michaelis constant (Km) for protoporphyrinogen IX was 0.1 microM. Due to the high affinity of the enzyme toward oxygen, the Km for oxygen could only be approximated to 0.5-1.5 microM. The purified enzyme contained a flavin as cofactor. Studies with rabbit antibodies to yeast protoporphyrinogen oxidase showed that the enzyme is synthesized as a high molecular weight precursor (58 kDa) that is rapidly converted in vivo to the mature (55 kDa) membrane-bound form. Protoporphyrinogen oxidase activity was found only in purified yeast mitochondrial inner membrane (not in the outer membrane). Acifluorfen-methyl, a potent diphenylether-type herbicide, competitively inhibited the purified enzyme (Ki = 10 nM). The mixed inhibition by acifluorfen-methyl previously reported for the membrane-bound protoporphyrinogen oxidase (Camadro, J.M., Matringe, M., Scalla, R., and Labbe, P. (1991) Biochem. J. 277, 17-21) was shown to be related to partial proteolysis of the enzyme.
Write Activity Minimization for Nonvolatile Main Memory Via Scheduling and Recomputation (2011)

Nonvolatile memories such as Flash memory, phase change memory (PCM), and magnetic random access memory (MRAM) have many desirable characteristics for embedded systems to employ them as main memory. However, there are two common challenges we need to answer before we can apply nonvolatile memory as main memory practically. First, nonvolatile memory has limited write/erase cycles compared to DRAM. Second, a write operation is slower than a read operation on nonvolatile memory. These two challenges can be answered by reducing the number of write activities on nonvolatile main memory. In this paper, we proposed two optimization techniques, write-aware scheduling and recomputation, to minimize write activities on nonvolatile memory. With the proposed techniques, we can both speed up the completion time of programs and extend nonvolatile memory's lifetime. The experimental results show that the proposed techniques can reduce the number of write activities on nonvolatile memory by 55.71% on average. Thus, the lifetime of nonvolatile memory is extended to 2.5 times as long as before on average. The completion time of programs can be reduced by 56.67% on systems with NOR Flash memory and by 47.63% on systems with NAND Flash memory on average.
Expanding the Silicon Photonics Portfolio With Silicon Nitride Photonic Integrated Circuits (2016)

The high index contrast silicon-on-insulator platform is the dominant CMOS compatible platform for photonic integration. The successful use of silicon photonic chips in optical communication applications has now paved the way for new areas where photonic chips can be applied. It is already emerging as a competing technology for sensing and spectroscopic applications. This increasing range of applications for silicon photonics instigates an interest in exploring new materials, as silicon-on-insulator has some drawbacks for these emerging applications, e.g., silicon is not transparent in the visible wavelength range. Silicon nitride is an alternate material platform. It has moderately high index contrast, and like silicon-on-insulator, it uses CMOS processes to manufacture photonic integrated circuits. In this paper, the advantages and challenges associated with these two material platforms are discussed. The case of dispersive spectrometers, which are widely used in various silicon photonic applications, is presented for these two material platforms.
Difference-frequency generation in AgGaS_2 by use of single-mode diode-laser pump sources (1993)

We explored the suitability of visible III–V single-mode cw diodes for difference-frequency generation of tunable infrared radiation by mixing a red single-mode cw III–V diode laser with a tunable single-frequency cw Ti:sapphire laser in AgGaS2. More than 1 μW of cw tunable, infrared (λ ≈ 5 μm), narrow-band coherent radiation was generated with type I noncritical phase matching. The wavelength and output-power characteristics of this novel tunable all-solid-state laser source are described, and we demonstrate the applicability of the source to high-resolution molecular spectroscopy by obtaining a test spectrum. The feasibility of a more compact solid-state cw laser spectrometer based on the mixing of two single-mode diode lasers (808 and 690 nm) as pump sources in AgGaS2 is shown (infrared power generated ≈3 nW).
Magnetic-adhesive based valves for microfluidic devices used in low-resource settings (2016)

Since the introduction of micro total analytical systems (μTASs), significant advances have been made toward development of lab-on-a-chip platforms capable of performing complex biological assays that can revolutionize public health, among other applications. However, use of these platforms in low-resource environments (e.g. developing countries) has yet to be realized as the majority of technologies used to control microfluidic flow rely on off-device hardware with non-negligible size, cost, power requirements and skill/training to operate. In this paper we describe a magnetic-adhesive based valve that is simple to construct and operate, and can be used to control fluid flow and store reagents within a microfluidic device. The design consists of a port connecting two chambers on different planes in the device that is closed by a neodymium disk magnet seated on a thin ring of adhesive. Bringing an external magnet into contact with the outer surface of the device unseats and displaces the valve magnet from the adhesive ring, exposing the port. Using this configuration, we demonstrate on-device reagent storage and on-demand transport and reaction of contents between chambers. This design requires no power or external instrumentation to operate, is extremely low cost ($0.20 materials cost per valve), can be used by individuals with no technical training, and requires only a hand-held magnet to actuate. Additionally, valve actuation does not compromise the integrity of the completely sealed microfluidic device, increasing safety for the operator when toxic or harmful substances are contained within. This valve concept has the potential to simplify design of μTASs, facilitating development of lab-on-a-chip systems that may be practical for use in point-of-care and low-resource settings.
Aerodynamic Impact of Manufacturing Variation on a Nonaxisymmetric Multi-Passage Turbine Stage With Adjoint CFD (2019)

Abstract Turbomachinery blade design is based on an axisymmetric model assuming identical blades in the circumferential direction. The blade manufacturing process, however, has a finite accuracy leading to surface imperfections and therefore non-identical blades. This leads to a variation in each passage cross area effecting the aerodynamic performance of the turbine. The simulation of multiple 3D CFD blade passages, nevertheless, is still computational expensive. However, if the effect of nonaxisymmetric blades is small enough to be approximated as linear, the adjoint method is an inexpensive alternative, which can be used in an industrial context. A set of 102 turbine vanes is used to model the manufacturing variations and assess the aerodynamic impact of up to eight nonaxisymmetric blade passages of a transonic high pressure turbine stage. It is shown that the modeled blade passage results superimpose linearly. Therefore, the aerodynamic impact of surface imperfections can be evaluated by superpositioning the singlepassage results, which are generated by an adjoint computation.
INTERACTIONS BETWEEN La2O3 PARTICLES AND DISLOCATIONS IN Mo-La2O3 ALLOYS (2005)

The mechanical properties of molybdenum wires doped with different contents of La2O3 were investigated systematically and the interaction between La2O3 particles with dislocations in MoLa2O3 wires were observed by SEM and TEM. It is shown that Mo-La2O3 wires possess much higher tensile strength than the pure Mo. In wires the dislocation motion is strongly hindered by La2O3 particles, which remains up to much higher temperature. Moreover, a number of prismatic dislocation loops and hexagonal dislocation network have been formed in annealed Mo-La2O3wires. The higher strength of Mo-La2O3 than the pure Mo is attributed to the La2O3 particles dispersion strengthening and dislocation strengthening.
Electrostatic potential surfaces of the transition state for AMP deaminase and for (R)-coformycin, a transition state inhibitor. (1994)

The transition state for the hydrolysis of AMP by AMP deaminase has been characterized by heavy atom kinetic isotope effects (Merkler, D.J., Kline, P.C., Weiss, P., and Schramm, V.L. (1993) Biochemistry 32, 12993-13001). The experimentally established transition state includes a bond order of 0.8 to the attacking water nucleophile, a full bond order to the exocyclic 6-amino group, rehybridization of C-6 of the purine ring to sp3 and protonation of N-1 by Glu633. The transition state is one the path to formation of an unstable tetrahedral intermediate in which the exocyclic amine undergoes rapid protonation followed by its departure. In this mechanism, the highest energetic barrier on the reaction coordinate is the attack of the zinc-activated water. In a further test of this transition state structure, the electrostatic potential surface for the purine ring of the transition state has been determined by molecular orbital calculations and compared to that of the base of (R)-coformycin 5'-monophosphate, a slow onset, tight binding inhibitor of AMP deaminase that binds with an overall dissociation constant of 10(-11) M. The electrostatic potential surfaces of the aglycones of the transition state and (R)-coformycin are compared to the adenine ring of the substrate and to an alternative transition state structure in which the transition state is late, with fully bonded hydroxyl and fully protonated exocyclic amine. The results indicate a near-match of the electrostatic potential surfaces for the early transition state and (R)-coformycin. The electrostatic nature of the late transition state with a protonated amine leaving group differs both from the transition state determine by kinetic isotope effects and from that of (R)-coformycin analogues. The results provide evidence that the nature of the enzyme-stabilized transition state for adenine deamination involves an early transition state with a partially bonded hydroxyl group. The observed tight binding inhibition by (R)-coformycin analogues as transition state inhibitors results from the similarity of the partial charges on the inhibitors to that of the enzymatic transition state stabilized by AMP deaminase.
Long-term measurement of spontaneous membrane fluctuations over a wide dynamic range in the living cell by low-coherent quantitative phase microscopy (2012)

Surface topography and its dynamic fluctuations in live cultured cells were obtained by low-coherent quantitative phase microscopy (LC-QPM), using a reflection-type interference microscope employing the digital holographic technique with a low-coherent light source. Owing to the low coherency of the light-source, only the light reflected at a specific sectioning height of the sample generates interference fringes on the CCD camera. Because the digital holographic technique enables us to quantitatively measure the intensity and phase of the optical field, a nanometer-scale surface profile of a living cell can be obtained by capturing the light reflected by the cell membrane. The lateral and the vertical spatial resolution was 0.56 microns and 0.93 microns, respectively, and the mechanical stability of the phase measurement was better than 2 nanometers. The measurements were made at fast (21 frames/sec) and slow (2 frames/sec, time-lapse) frame rates and the slow measurements were performed over a period of 10 minutes. The temporal fluctuations of the cell membrane were analyzed by the mean-square-displacement (MSD) as a function of the time-difference τ. By merging the fast and slow data, the MSDs from τ = 50 msec to τ = 300 sec were obtained and wide-dynamic-range measurements of the MSDs from 2 nm<sup>2</sup> to over 100000 nm<sup>2</sup> were demonstrated. The results show significant differences among different cell types under various conditions.
Aminolysis of Resin-Bound <i>N</i>-Nosylaziridine-2-carboxylic Acids (2006)

[Structure: see text] Solid-phase synthesis is a rapidly developing area of organic chemistry, of particular importance for medicinal chemistry and chemical biology. Aziridines have previously only rarely been applied in solid-phase synthesis. In the present work, aminolysis of resin-bound, spring-loaded N-nitrobenzenesulfonyl-activated aziridine-2-carboxylic acids has been optimized and employed in the synthesis of a number of open-chain and heterocyclic scaffolds, including enantiopure products.