gebhart/patrepeval huggingface dataset:
A review and outlook for an anomaly of scanning tunnelling microscopy (STM): superlattices on graphite (2005)

Since its invention in 1981, scanning tunnelling microscopy (STM) is well-known for its supreme imaging resolution enabling one to observe atomic-scale structures, which has led to the flourishing of nanoscience. As successful as it is, there still remain phenomena which are observed using STM but are beyond our understanding. Graphite is one of the surfaces which have been most extensively studied using STM. However, there are a number of unusual properties of graphite surfaces. First reported in the 1980s, superlattices on graphite have since been observed many times and by many groups, but as yet our understanding of this phenomenon is quite limited. Most of the observed superlattice phenomena are widely believed to be the result of a Moiré rotation pattern, arising from the misorientation between two graphite layers, as verified experimentally. A Moiré pattern is a lattice with larger periodicity resulting from the overlap of two lattices with smaller periodicities. As graphite layers are composed of hexagonal lattices with a periodicity of 0.246 nm, as observed using STM, when there are misoriented graphite layers overlapping each other, a Moiré pattern with larger periodicity, depending on the misorientation angle, will be produced and appear as a superperiodic hexagonal structure on top of the graphite atomic lattice of the topmost surface layer. It is important to study graphite superlattices because, firstly, knowledge of this phenomenon will enable us to properly interpret STM images; secondly, it helps us to understand the correlation between electronic structures and atomic-structure rearrangement of graphite which is of tremendous aid for engineering material properties; thirdly, and perhaps most importantly, the observation of the phenomenon exhibits the capability of STM to produce images indicating the nature of internal defects which are below the surface. Over recent years, experimental and modelling techniques have been developed to study this anomalous regime of STM; however, there is a lack of a systematic classification of this scattered information. This review article thus serves the purpose of organizing all these results so as to enable a more comprehensive understanding of this phenomenon. We review the discovery of graphite superlattices, the observation of the associated properties, and the research efforts on this subject. An effort is made to envision the future experimental and theoretical research possibilities to unveil the mystery of this anomaly of STM. Applications of graphite superlattices are also proposed. © 2005 IOP Publishing Ltd.
Field emission from GaAs pyramids fabricated using selected area vapor phase epitaxy (2002)

We report the fabrication of GaAs pyramids using selected area organometallic vapor phase epitaxy (SA-OMVPE) and field emission characteristics obtained from these structures. The use of crystal planes to define structure surfaces offers an attractive way of fabricating atomically sharp tip apexes in field emitter arrays (FEAs). For example, diamond crystals typically form such sharp apex structures. To use crystal structures as field emitters in a FEA, the orientation and size of the crystal surfaces must be controllable and consistent over the array, and the crystal should have electronic properties compatible with field emission. When high transconductance or high emission currents are required, these electronic properties should include a low resistance electron injecting contact, high bulk conductivity, and a modest surface potential barrier for electron field emission. In addition, formation of the tip structure must be compatible with formation of an adequate gate aperture. III-V semiconductor crystals grown by SA-OMVPE may provide a material and fabrication system capable of satisfying all these requirements.
Energies, structures, and electronic properties of molecules in solution with the C‐PCM solvation model (2003)

The conductor-like solvation model, as developed in the framework of the polarizable continuum model (PCM), has been reformulated and newly implemented in order to compute energies, geometric structures, harmonic frequencies, and electronic properties in solution for any chemical system that can be studied in vacuo. Particular attention is devoted to large systems requiring suitable iterative algorithms to compute the solvation charges: the fast multipole method (FMM) has been extensively used to ensure a linear scaling of the computational times with the size of the solute. A number of test applications are presented to evaluate the performances of the method.
Microfluidic Devices Targeting Blood Cell Lysis (2012)

Cell lysis is an essential step in whole blood sample preparation, which can pave road for intracellular proteomic analysis or genomic analysis and therefore cell membrane rupture is requested for protein and gene release. In this chapter, we firstly introduce reported microfluidic devices for cell lysis. And then an example using the chemical cell lysis method in microfluidic chip is put forward in which a sandwich microfluidic chip was designed, fabricated and tested to disrupt blood cell membranes.
Gait Rehabilitation With an Active Leg Orthosis (2005)

In this paper, we discuss the design and control strategies for an active gait rehabilitation device for the lower extrmity. This device uses gravity balancing to reduce the net torque required by the actuators during motion. Two controllers are proposed in this paper. The first uses a robust controller and the second uses a torque assisting control law. Simulations of these controllers are presented in this paper. Experiments are currently being conducted with this orthosis on healthy and stroke subjects.
SYNTHETIC APERTURE IMAGING AND AUTOFOCUS WITH COHERENT MIMO SONAR SYSTEMS (2023)

MIMO stands for Multiple Inputs Multiple Outputs. Such systems have received a lot of interests in the radar community during the last decade1 . One of the main reason behind this is the greater variety in terms of target view angles compared with traditional monostatic systems. With several independent views one can hope to reduce the speckle effect typical of coherent sensor systems such as RADAR or SONAR. Destructive interference in particular can be the cause of missed detection. MIMO sonar systems have been studied by the ASW2,3 (anti-submarine warfare) community mainly to increase the probability of detection of low strength target. Few MIMO systems have been built and tested including DEMUS (LF SIMO system built by CMRE). In any case all those systems use a relatively low number of sensors.
Neutral hydrogen in IC 342 - II. The detailed structure (1980)

H <scp>I</scp> in the Scd galaxy IC342 has been studied with a resolution in radial velocity of 16 km s–1 and with an angular resolution (1.9 × 2.0 arcmin) sufficient to resolve detailed spiral structure. Spiral arms extend over the outer, warped parts of the disc, and reach the limit of detected H <scp>I</scp> at ∼ 40 arcmin (50 kpc) from the nucleus. The pattern is multi-armed, with the clearest features lying beyond the observed optical emission, and inner arms which are well correlated with other Population I material. If the arms are quasi-stationary density-wave features, the absence of radial streaming motions > 5 km s–1 implies a small pattern speed. A marginal detection of such motions along one arm is consistent both with this result and with the conclusion derived from the H <scp>I</scp> distribution that corotation is between 16 and 21 kpc from the nucleus, and the pattern speed is ∼ 10 km s–1 kpc–1.
Joint Mitigation of Power Amplifier and I/Q Modulator Impairments in Broadband Direct-Conversion Transmitters (2010)

In this paper, we present a novel digital predistorter structure for joint mitigation of frequency-dependent power amplifier (PA) and in-phase and quadrature (I/Q) modulator impairments in direct-conversion radio transmitters. The predistorter is based on an extended parallel Hammerstein structure, yielding a predistorter that is fully linear in the parameters. In the parameter estimation stage, the indirect learning architecture is utilized. The proposed technique is the first technique in the literature to consider the joint estimation and mitigation of frequency-dependent PA and I/Q modulator impairments. Extensive simulation and measurement analysis is carried out to verify the operation and efficacy of the proposed predistortion structure. It is shown that the adjacent channel power ratio is increased by more than 20 dB in all experiments when using the proposed method, and that the performance of the reference techniques is clearly exceeded.
Ghrelin as a Potential Anti-Obesity Target (2003)

In order to develop an effective pharmacological treatment for obesity, an endogenous factor that promotes a positive energy balance by increasing appetite and decreasing fat oxidation could represent the drug target scientists have been looking for. The recently discovered gastric endocrine agent ghrelin, which appears to be the only potent hunger-inducing factor to naturally circulate in our blood stream, was discovered in 1999. Since then the acylated peptide hormone ghrelin has evolved from an endogenous growth hormone secretagogue to a regulator of energy balance to a pleiotropic hormone with multiple sources, numerous target tissues and most likely several physiological functions. Although neither the exact mechanism of action by which ghrelin increases food intake and adiposity is known, nor the putatively differential effects of brain-derived and stomach-derived ghrelin on energy homeostasis have been determined, blocking or neutralizing ghrelin action still seems one of the more reasonable pharmacological approaches to reverse a chronically positive energy balance. However, based on growing experience with compounds targeting the neuroendocrine regulation of energy balance, it is quite possible that a ghrelin antagonist will either fail to cure obesity due to the existence of compensatory mechanisms or undesired effects might reveal the true biological function of ghrelin (e.g. cardiovascular mechanisms, anti-proliferative effects, reproduction).
High‐level Production, Chemical Modification and Site‐directed Mutagenesis of a Cephalosporin C Acylase from <i>Pseudomonas</i> Strain N176 (1995)

A cephalosporin acylase from Pseudomonas strain N176 hydrolyses both 7-beta-(4-carboxybutanamido)-cephalosporanic acid (glutarylcephalosporanic acid) and cephalosporin C to 7-amino-cephalosporanic acid. However, its productivity in the original host was low and its activity against cephalosporin C was not sufficient for direct large-scale production of 7-amino-cephalosporanic acid. In order to overcome these problems, we established a high-level expression system for the acylase in Escherichia coli. Tyr270 in the acylase is reported to play an important role in the interaction with glutarylcephalosporanic acid, as determined from the reaction with an affinity-label reagent, 7 beta-(6-bromohexanoylamido) cephalosporanic acid [Ishii, Y., Saito, Y., Sasaki, H., Uchiyama, F., Hayashi, M., Nakamura, S. & Niwa, M. (1994) J. Ferment. Bioeng. 77, 598-603] and modification with tetranitromethane [Nobbs, T. J., Ishii, Y., Fujimura, T., Saito, Y. & Niwa, M. (1994) J. Ferment. Bioeng. 77, 604-609]. From carbamoylation with potassium cyanate and site-directed point mutagenesis of the cephalosporin C acylase, we have deduced that Tyr270 exists at a position where it can interact with a residue (possibly Ser239) corresponding to inactivation by carbamoylation. We mutated Met269 and Ala271 of the acylase and found that mutation of Met269 to Tyr or Phe caused a 1.6-fold and 1.7-fold increase, respectively, of specific activity against cephalosporin C as compared to that of the wild-type enzyme. Kinetic studies of these mutants revealed that their kcat values increased, although their Km values against cephalosporin C were not changed. These data indicate that the mutation of Met269 near Tyr270 induces a minor conformational change to increase the stability of the activated complex with the enzyme and cephalosporin C. In particular, a mutant in which Met269 was replaced by Tyr was 2.5-fold more efficient in converting cephalosporin C to 7-amino-cephalosporanic acid than the wild-type enzyme under conditions similar to those in a bio-reactor system.
Autonomous Vehicle Following System In Off-road Environment (2020)

To solve the problem of vehicle formation transportation in off-road environment, we design an autonomous vehicle following control system based on detection, realizing vehicle following on muddy bumpy and crooked roads with a maximum speed of 35 km/h. First, the detection algorithm of multi-sensor fusion is applied to detecting and tracking the guiding vehicle. Then an anti-interference feedback controller is designed for speed tracking and an emergency braking algorithm is designed to improve the safety of emergency. A lateral controller according to kinematic model is designed for lateral tracking. Furthermore, the robustness and adaptability of the proposed method are validated by joint simulations of Carsim and MATLAB/Simulink. Finally, the system is deployed on an electric unmanned vehicle to realize vehicle autonomous following with a maximum speed of 35 km/h on a 3.6 km stretch of road with bump, muddy and continuous curves. The results demonstrate the accuracy of detection and the stability of the tracking.
Oriented Gelatin—A New Source for High-Performance Materials (1996)

Abstract Two types of gelatin with different gel-forming capabilities (“bloom values”) were used in a novel processing technique to improve their mechanical properties when in the form of films. Networks consisting of the water-soluble gelatin chains were prepared by diisocyanate crosslinking in 2,2,2-trifluoroethanol—in which gelatin forms no collagen folds (physical junctions) at room temperature. The liquid-crystalline behavior of both the uncrosslinked gelatin and its networks were studied with regard to the effects of molecular weight and nature of the solvent. Mechanical property measurements indicated dramatic increases in tensile strength, tensile modulus, and toughness after drying the swollen films under stain, both uniaxial and equi-biaxial. The improvements in mechanical properties were determined as a function of polymer concentration at stretching, elongation during drying, and molecular weight of the gelatin. In all cases the improvements increased monotonically with the increase of elongation during drying. Further-more, equi-biaxial orientation resulted in almost twofold improvements in tensile strength and modulus compared to those from uniaxial orientation (at essentially the same extension ratio during drying). Additional characterization, in terms of the extent of ordering in these oriented networks, was obtained from birefringence measurements. In overall performance the oriented gelatin films can be described as tough plastics, with tensile strengths between 65 and 140 MPa and elongations at break of 15–20%.
Study of the dispersion of an air-core photonic bandgap fiber and its application as a linear chirped pulse compressor (2004)

We study the dispersion of an air-core photonic bandgap fiber and show its application in chirped pulse amplification. ~500 fs pulses, stretched to ~ 100 ps using dispersion-compensating fiber, were re-compressed to ~1ps in 10 m of this fiber
Artifactual variation in randomly amplified polymorphic DNA banding patterns. (1993)

Randomly amplified polymorphic DNA (RAPD) and arbitrarily primed PCR (AP-PCR) represent novel DNA polymorphism assays that involve the amplification of random DNA segments using PCR and oligonucleotide primers of arbitrary sequence. Products defining the polymorphisms exhibit Mendelian inheritance and thus possess tremendous potential utility as genetic markers in a diverse array of scientific disciplines. Amplification profiles for specific oligonucleotide primers are highly dependent on the specific conditions of the reaction; banding patterns may thus vary extensively because of inconsistencies in a number of reaction parameters. Artifactual variation represents a potential problem in surveys of genetic variation in natural populations and must be discriminated from true polymorphism for the applications of RAPD to be both accurate and reliable.
HIV-1/ <i>Mycobacterium tuberculosis</i> Coinfection Immunology: How Does HIV-1 Exacerbate Tuberculosis? (2011)

Human immunodeficiency virus type 1 (HIV) and Mycobacterium tuberculosis have become intertwined over the past few decades in a "syndemic" that exacerbates the morbidity and mortality associated with each pathogen alone. The severity of the coinfection has been extensively examined in clinical studies. The extrapolation of peripheral evidence from clinical studies has increased our basic understanding of how HIV increases susceptibility to TB. These studies have resulted in multiple hypotheses of how HIV exacerbates TB pathology through the manipulation of granulomas. Granulomas can be located in many tissues, most prominently the lungs and associated lymph nodes, and are made up of multiple immune cells that can actively contain M. tuberculosis. Granuloma-based research involving both animal models and clinical studies is needed to confirm these hypotheses, which will further our understanding of this coinfection and may lead to better treatment options. This review examines the data that support each hypothesis of how HIV manipulates TB pathology while emphasizing a need for more tissue-based experiments.
8-hz telluric and magnetotelluric prospecting (1972)

Abstract Sulfide deposits, telluric method preferred, natural electromagnetic fields
Role of Ebola Virus VP30 in Transcription Reinitiation (2008)

VP30 is a phosphoprotein essential for the initiation of Ebola virus transcription. In this work, we have studied the effect of mutations in VP30 phosphorylation sites on the ebolavirus replication cycle by using a reverse genetics system. We demonstrate that VP30 is involved in reinitiation of gene transcription and that this activity is affected by mutations at the phosphorylation sites.
Serum antibodies to secreted proteins in patients infected with <i>Escherichia coli</i> O157 and other VTEC (1998)

Certain strains of verotoxigenic Escherichia coli (VTEC), and in particular those belonging to serogroup O157, cause attaching and effacing (AE) lesions of the host gut mucosa during pathogenesis. The mechanisms involved with bacterial attachment and the destruction of microvilli are determined by a cluster of genes within the LEE region, which also encode five secreted proteins. Sera from patients with antibodies to the lipopolysaccharide (LPS) of E. coli O157 and other VTEC were tested for antibodies to these secreted proteins. Twenty-one of 34 (62%) sera with antibodies to the lipopolysaccharide (LPS) of E. coli O157 also contained antibodies to one or more of the secreted proteins. Five of 12 sera containing antibodies to the LPS of a range of other VTEC serogroups also contained antibodies to 1 or more of the 5 secreted proteins, as did 16 of 70 (23%) sera from patients with haemolytic uraemic syndrome (HUS), haemorrhagic colitis (HC) or diarrhoea, but without bacteriological evidence of infection with VTEC and which did not contain antibodies to VTEC serogroups O5, O115, O145, O153 or O157. The detection of serum antibodies to secreted proteins may provide additional information for interpreting the results of established lipopolysaccharide-based VTEC serology.
Experimental Study of Distal Interlocking of a Solid Tibial Nail: Radiation-Independent Distal Aiming Device (DAD) Versus Freehand Technique (FHT) (1998)

These results suggest that the DAD can eliminate the need for radiation during placement of distal interlocking screws.
Comparison of Halbach magnetized brushless machines based on discrete magnet segments or a single ring magnet (2002)

This paper compares the air-gap field distribution, cogging torque, back-electromotive-force waveform, and efficiency of brushless machines having a Halbach magnetization produced by either discrete magnet segments or a single ring magnet. Results deduced from finite-element analyses are compared with measurements, and the performance of Halbach magnetized machines is compared with that of machines equipped with radially magnetized magnets.
Further Advances in Chemistry and Technology of Acid-Hardened Resists. (1991)

This paper describes further developments of Acid Hardened Resist (AHR) systems, with particular focus on the DUV and i-line AHR resist performance. Results regarding the time delay between exposure and post-exposure bake are given for MegapositSNRT'248 photoresist over a 23 hour time delay, with no effect observed on the 0.5 m linewidths. Li thographic performance for the i-line and DUV resists is also presented. Using i-line phase-shift mask technology 0.35 m lines and spaces are printed with the i-line AHR resist. Finally, results are presented comparing the relative solubility of crosslinked resist films of SNR248 in tetrahydrofuran vs. various normality levels of tetramethylammonium hydroxide (TMAH). These results lead us to the conclusion that phenolic hydroxyl site blocking plays a role in dissolution inhibition in TMAH developers.
Frequency Modulation and Control by Electron Beams (1947)

General formulas for the effect of electron beams on resonant systems in terms of frequency shift and change in Q are derived from the point of view of lumped circuits and from a general electromagnetic field standpoint. A way of introducing the electrons has been found which materially enhances their effectiveness in producing a shift of frequency in a resonant system. Measurements of the frequency shift produced by such an electron beam in a typical geometry were made which check well with values calculated from the general theory. Possible amplitude and phase distortions are calculated when such a beam is used to frequency-modulate a system, and these are found to be negligibly small, even for very high modulating frequencies. It is shown that this method of frequency control is ideally suited for frequency modulation or automatic frequency stabilization of continuous-wave magnetron oscillators using negative-grid-controlled electron beams for controlling the frequency of oscillations.
The platelet proteome (2009)

Proteomic experiments in resting and activated platelets have identified novel signaling pathways and secreted proteins which may represent therapeutic targets, as well as potential cancer biomarkers.
Deblocking algorithm for DCT-based compressed images using anisotropic diffusion (2003)

Among many image compression approaches, the discrete cosine transform (DCT) is widely used. However, dividing an image into small blocks prior to coding causes "blocking artifacts". A deblocking algorithm is proposed for DCT-based compressed images using anisotropic diffusion; it is derived from the ALM (Alvarez, Lions, Morel) diffusion model (Alvarez, L. et al., SIAM J. Numer. Anal., vol.29, no.3, p.845-66, 1992). It can control the diffusion rate in the normal direction of the edges using a "rate control parameter". It functions not only as an isotropic diffusion at block boundaries of smooth regions, but also as an anisotropic diffusion that diffuses the image only in the normal direction of the edges at edges or block boundaries of texture regions. The rate control parameters at block boundaries are chosen carefully to reduce discontinuities. To avoid oversmoothing of the texture region, a "speed parameter" is employed. The speed parameter makes the diffusion process slow at the texture region, while making it fast at the smooth region.