gebhart/patrepeval huggingface dataset:
A novel 3-D subsurface radar imaging technique (2002)

The problem of the formation of subsurface images using stand-off forward looking radar is by far more severe than that of forming the radar images in the free-space. A subsurface image needs to be accurately focused taking into account both the refraction and dispersion of the wavefield. This paper presents a novel imaging algorithm specially tailored for subsurface sensing. A simple and effective characterization technique for the retrieval of the dielectric permittivity is outlined. The proposed soil characterization and subsurface imaging techniques are validated experimentally. Results show that the geometric distortion in the subsurface images due to the refraction and dispersion of the wavefields is successfully corrected.
Vanadium dioxide devices for terahertz wave modulation: a study of wire grid structures (2016)

Vandium dioxide (VO2) shows promise as the basis for a terahertz wave modulator due to its phase transition properties. Its insulator-metal-transition (IMT) can be induced either through temperature changes, optically or electronically. Recently, a metal-VO2 wire grid structure was proposed which was able to increase the modulation depth (MD) from 0.65 to 0.9, suggesting that these simple metallic structures could greatly increase the difference in terahertz transmission for the insulating and metallic states of VO2 based structures. In this paper, we have found that the increase in MD decreases with increasing VO2 conductivity in the metallic state, resulting in a maximum modulation depth of approximately 0.95 for wire grid structures that preserves a high transmission in the insulating state. Surprisingly, we find that deposition of VO2 on top of metallic structures results in reduced performance. However, we find that devices based upon VO2 alone can achieve unexpectedly high performance. In this work we present a device with a switchable wire-grid polariser effect over a broadband frequency range (from 0.3 to 2 THz). To our knowledge this is the first such broadband metamaterial based solely on VO2. The ability to switch on a metamaterial property like this to produce a polarisation effect is very useful for future terahertz optical devices such as rotators and waveplates.
Development of Visual Diagnostic Expertise in Pathology: An Information-processing Study (2003)

Objective: To identify key features contributing to trainees’ development of expertise in microscopic pathology diagnosis, a complex visual task, and to provide new insights to help create computer-based training systems in pathology. Design: Standard methods of information-processing and cognitive science were used to study diagnostic processes (search, perception, reasoning) of 28 novices, intermediates, and experts. Participants examined cases in breast pathology; each case had a previously established gold standard diagnosis. Videotapes correlated the actual visual data examined by participants with their verbal “think-aloud” protocols. Measurements: Investigators measured accuracy, difficulty, certainty, protocol process frequencies, error frequencies, and times to key diagnostic events for each case and subject. Analyses of variance, chi-square tests and post-hoc comparisons were performed with subject as the unit of analysis. Results: Level of expertise corresponded with differences in search, perception, and reasoning components of the tasks. Several discrete steps occur on the path to competence, including development of adequate search strategies, rapid and accurate recognition of anatomic location, acquisition of visual data interpretation skills, and transitory reliance on explicit feature identification. Conclusion: Results provide the basis for an empirical cognitive model of competence for the complex tasks of microscopic pathology diagnosis. Results will inform the development of computer-based pedagogy tools in this domain
Heat transfer modelling of two-phase bubbles swarm condensing in three - phase direct - contact condenser (2014)

An analytical model for the convective heat transfer coefficient and the two-phase bubble size of a three-phase direct contact heat exchanger was developed. Until the present, there has only been a theoretical model available that deals with a single two-phase bubble and a bubble train condensation in an immiscible liquid. However, to understand the actual heat transfer process within the three-phase direct contact condenser, characteristic models are required. A quasi - steady energy equation in a spherical coordinate system with a potential flow assumption and a cell model configuration has been simplified and solved analytically. The convective heat transfer in terms of Nu number has been derived, and it was found to be a function to Pe number and a system void fraction. In addition, the two-phase bubble size relates to the system void fraction and has been developed by solving a simple energy balance equation and using the derived convective heat transfer coefficient expression. Furthermore, the model correlates well with previous experimental data and theoretical results.
ChemInform Abstract: Stereocontrolled Construction of Six Vicinal Stereogenic Centers on Spiropyrazolones via Organocascade Michael/Michael/1,2‐Addition Reactions. (2014)

Abstract A one‐pot protocol for the synthesis of spiropyrazolones via sequential reaction of β‐dicarbonyl compounds, nitroalkenes, and pyrazolones catalyzed by a cinchona derived aminosquaramide and DBU is developed.
Parallelism analyzers for parallel discrete event simulation (1992)

Discrete event simulation is usually time consuming. Recently, there has been a great deal of interest in using parallel computers to speed up the simulation process. Before the parallel simulation approach is applied, it is important to understand the inherent parallelism of simulation applications. A simple technique called critical path analysis was proposed to study paralllelism of simulation applications. This paper describes three critical path analysis algorithms based on different event-scheduling (process scheduling) policies. These algorithms are much simpler than a previous approach, where the events must be recorded in a trace and an extra pass is required to process the event trace. In our approach, the critical path analysis algorithms are integrated with the sequential simulation. At the end of the sequential simulation, the optimal parallel execution time is also computed. Livny proposed an algorithm similar to our approach (His, however, was designed for a specific language). Our algorithms can be integrated with sequential simulation programs written by users or be integrated with simulation languages. Another advantage of our algorithms over previous approaches is that ours can be used to study load balancing under different event-scheduling policies. Since our algorithms can be easily inserted in sequential simulation programs, critical path analysis can be applied to existing sequential programs without difficulty. The results can then be used to predict the performance of parallel simulation on similar applications. An example is given to show how useful information can be obtained from our algorithms.
Statistical Response of a Class of Hysteretic Systems (1994)

The response of a hysteretic nonlinear system subjected to a filtered white noise is considered. The method of time-dependent equivalent linearization is used and the moment equations governing the nonstationary response statistics are formulated. For a rangeof values of parameters, root-mean-square responses of the isolator are evaluated. The results are compared with those obtained from the Monte-Carlo digital simulations and reasonable agreement is observed.
Interface limited hole extraction from methylammonium lead iodide films (2019)

A new method is proposed to determine charge diffusion coefficient and transfer velocity to extraction layers. Hole diffusion coefficient in MAPbI<sub>3</sub> is constant between 10<sup>16</sup> – 10<sup>17</sup> cm<sup>−3</sup>, a hallmark of band transport but overall extraction is interface limited.
Interactions of rutaecarpine alkaloids with specific binding sites for 2,3,7,8-tetrachlorodibenzo-p-dioxin in rat liver (1989)

Rutaecarpine alkaloids have the capacity to inhibit specific 2,3,7,8-[1,6-3H]tetrachlorodibenzo-p-dioxin (TCDD) binding in rat liver cytosol, as analysed by electrofocusing in polyacrylamide gel. The IC50 value for binding of 7,8-dehydrorutaecarpine was estimated to approximately 7 nM indicating a high-affinity interaction, whereas rutaecarpine appeared less active (IC50 approximately 110 nM). These findings are of interest in view of the fact that analogues to these compounds may be formed following UV-irradiation of tryptophan and that such photo-products have been suggested to constitute (the) endogenous ligand(s) for the TCDD receptor. As further support of this notion, the rutaecarpine alkaloids investigated could be fitted into a rectangle of 6.8 x 13.7 A, a characteristic common for most high affinity ligands of the TCDD receptor hitherto studied. In view of their structural similarity to dehydrorutaecarpine and the agreement of their mol. wt with that of the photoproduct with the highest affinity for the TCDD receptor, we suggest deaza-analogues of dehydrorutaecarpine to represent possible candidates for the endogenous TCDD receptor ligand.
Caulobacter chromosome in vivo configuration matches model predictions for a supercoiled polymer in a cell-like confinement (2013)

We measured the distance between fluorescent-labeled DNA loci of various interloci contour lengths in Caulobacter crescentus swarmer cells to determine the in vivo configuration of the chromosome. For DNA segments less than about 300 kb, the mean interloci distances, <r>, scale as n(0.22), where n is the contour length, and cell-to-cell distribution of the interloci distance r is a universal function of r/n(0.22) with broad cell-to-cell variability. For DNA segments greater than about 300 kb, the mean interloci distances scale as n, in agreement with previous observations. The 0.22 value of the scaling exponent for short DNA segments is consistent with theoretical predictions for a branched DNA polymer structure. Predictions from Brownian dynamics simulations of the packing of supercoiled DNA polymers in an elongated cell-like confinement are also consistent with a branched DNA structure, and simulated interloci distance distributions predict that confinement leads to "freezing" of the supercoiled configuration. Lateral positions of labeled loci at comparable positions along the length of the cell are strongly correlated when the longitudinal locus positions differ by <0.16 μm. We conclude that the chromosome structure is supercoiled locally and elongated at large length scales and that substantial cell-to-cell variability in the interloci distances indicates that in vivo crowding prevents the chromosome from reaching an equilibrium arrangement. We suggest that the force causing rapid transport of loci remote from the parS centromere to the distal cell pole may arise from the release at the polar region of potential energy within the supercoiled DNA.
EPAC2 acts as a negative regulator in Matrigel-driven tubulogenesis of human microvascular endothelial cells (2021)

Angiogenesis is physiologically essential for embryogenesis and development and reinitiated in adult animals during tissue growth and repair. Forming new vessels from the walls of existing vessels occurs as a multistep process coordinated by sprouting, branching, and a new lumenized network formation. However, little is known regarding the molecular mechanisms that form new tubular structures, especially molecules regulating the proper network density of newly formed capillaries. This study conducted microarray analyses in human primary microvascular endothelial cells (HMVECs) plated on Matrigel. The RAPGEF4 gene that encodes exchange proteins directly activated by cAMP 2 (EPAC2) proteins was increased in Matrigel-driven tubulogenesis. Tube formation was suppressed by the overexpression of EPAC2 and enhanced by EPAC2 knockdown in endothelial cells. Endothelial cell morphology was changed to round cell morphology by EPAC2 overexpression, while EPAC2 knockdown showed an elongated cell shape with filopodia-like protrusions. Furthermore, increased EPAC2 inhibited endothelial cell migration, and ablation of EPAC2 inversely enhanced cell mobility. These results suggest that EPAC2 affects the morphology and migration of microvascular endothelial cells and is involved in the termination and proper network formation of vascular tubes.
<title>High-efficiency microdrilling of silicon wafer using excimer laser</title> (2000)

Drilling rate of thin silicon wafer of 50(mu) thickness was determined as a function of beam diameter and laser fluence of KrF excimer laser with a pulse width of approximately 30ns FMHW. Analysis of drilling process indicated that decreasing beam diameter and laser fluence enhanced the drilling rate with improved quality of the drilled hole. The extent of debris and molten particles ejected from the hole was also reduced as the laser fluence was decreased. The drilling rate, approximately 0.6(mu) per pulse at beam diameters larger than 100(mu) , increased significantly as the beam diameter decreased especially below 20(mu) , reaching approximately as large as 4(mu) per pulse at 10(mu) in diameter under constant laser fluence. On the other hand, only very small increase in drilling rate was observed as the laser fluence was increased. A simple formula was derived where the drilling rate is proportional to the fourth root of the laser fluence and inversely proportional to the square root of the beam diameter, assuming that the silicon is removed in a liquid state out of the hole.
Molybdenum Carbides, Active and In Situ Regenerable Catalysts in Hydroprocessing of Fast Pyrolysis Bio-Oil (2016)

This paper describes properties of molybdenum carbides as a potential catalyst for fast pyrolysis bio-oil hydroprocessing. Currently, high catalyst cost, short catalyst lifetime, and lack of effective regeneration methods are hampering the development of this otherwise attractive renewable hydrocarbon technology. A series of metal-doped bulk Mo carbides were synthesized, characterized, and evaluated in sequential low-temperature stabilization and high-temperature deoxygenation of a pine-derived bio-oil. During a typical 60 h run, Mo carbides were capable of upgrading raw bio-oil to a level suitable for direct insertion into the current hydrocarbon infrastructure with residual oxygen content and total acid number of upgraded oils below 2 wt % and 0.01 mg KOH g–1, respectively. The performance was shown to be sensitive to the type of metal dopant, Ni-doped Mo carbides outperforming Co-, Cu-, or Ca-doped counterparts; a higher Ni loading led to a superior catalytic performance. No bulk oxidation or other significant structural changes were observed. Besides the structural robustness, another attractive property of Mo carbides was in situ regenerability. The effectiveness of regeneration was demonstrated by successfully carrying out four consecutive 60 h runs with a reductive decoking between two adjacent runs. These results strongly suggest that Mo carbides are a good catalyst candidate which could lead to a significant cost reduction in hydroprocessing bio-oils. We highlight areas for future research which will be needed to further understand carbide structure–function relationships and help design practical bio-oil upgrading catalysts based on Mo carbides.
Effects of Cooling Rate after Hot Forging on Precipitation of Fine Particles during Subsequent Normalizing and Austenite Grain Growth during Carburization of Al- and Nb-microalloyed Case-hardening Steel (2021)

This study deals with austenite grain growth during high-temperature carburization of an Al- and Nb-microalloyed case-hardening steel. The grain size after carburization-simulated heating for 5 h at 1050°C decreased with the increase in the cooling rate from hot forging-simulated heating for 1 h at 1250°C. The increase in cooling rate led to the decreases in the volume fractions and sizes of AlN and Nb(C,N) particles precipitated during cooling, and AlN disappeared when the cooling rate increased to 16°C/min, while Nb(C,N) still slightly exited at 16°C/min. Because of oversaturation caused by cooling within a finite time, further precipitation occurred during the subsequent normalization for 3 h at 1070°C, resulting in the formation of AlN–Nb(C,N) combined particles. When the cooling rate increased, the volume fraction and number density of these combined particles increased while their size decreased. Therefore, a higher cooling rate causes a larger pinning effect on grain growth during carburization; thus grain size after carburization decreased with the increase in cooling rate. Transmission electron microscopy confirmed the formation of a coherent AlN–Nb(C,N) interface due to good lattice matching between the crystal planes of AlN (1120) and Nb(C,N) (220). This led to the preferential nucleation of AlN on the Nb(C,N) particles, thereby forming stable AlN–Nb(C,N) particles.
Increased activity of the angiotensin converting enzyme C‐domain reduces melanoma growth by stimulating M1 macrophage polarization (2019)

ACE is composed of two independent catalytic domains. To investigate the specific role of each ACE domain in tumor resistance, we made transgenic mice which over express in myeloid cells either wild type ACE (Tg‐ACE mice) or ACE lacking N‐ or C‐domain catalytic activity (Tg‐NKO and Tg‐CKO mice). Tg‐ACE and Tg‐NKO mice strongly suppressed the growth of B16‐F10 melanoma due to increased ACE expression by macrophages. In contrast, Tg‐CKO mice resist melanoma no better than wild type animals. The effect of ACE over expression reverts to wild type with an ACE inhibitor but not with an AT1 receptor antagonist. Over expression of the ACE C‐domain in macrophages drives cells towards a pronounced M1 phenotype upon tumor stimulation, with increased activation of NF‐kB and STAT1, and decreased activation of STAT3 and STAT6. TNFα is important in M1 activation of macrophages; TNFα blockade reverted Tg‐NKO macrophages to a wild type phenotype. Increased ACE C‐domain expression induced increased levels of the transcription factor C / EBPβ in macrophages, an important stimulus for TNFα expression. In contrast, there was decreased expression of IL‐4Rα, a key receptor for M2 activation of macrophages. Natural ACE C‐domain specific substrates are not well described. Nonetheless, the peptide(s) responsible for the ACE‐mediated enhancement of myeloid function are substrates and products of only the ACE C‐domain. Support or Funding Information This study was supported by NIH grant P01HL129941 (KEB), AI143599 (KEB), R21AI114965 (KEB), R01HL142672 (JFG), P30DK063491 (JFG), AHA grant 17GRNT33661206 (KEB), and AHA grant 16SDG30130015 (JFG). This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .
Multi-distance motion vector clustering algorithm for video-based sleep analysis (2013)

Overall health and daily functioning deteriorate with poor sleep. To improve one's sleep, sleep monitoring can help identifying causes of sleep problems. As an advantage over traditional wrist actigraphy used in home sleep monitoring solutions, video contains more comprehensive movement information. Particularly, different body movements can be distinguished which is beneficial for a more detailed sleep analysis. We developed an efficient K-Means clustering method with a multi-distance seeding technique to find the dominant cluster candidates. An integrated multi-distance dissimilarity measure was used for the subsequent clustering. We present an automatic content-dependent weight tuning method for the dissimilarity measure to balance between different distance descriptors. This discriminative algorithm partitions similar body movements in the same cluster. We were able to produce several dissimilarity measures producing clusters that agreed 67% with manual clustering of motion vectors by one expert. Similar clustering characteristics were preferred by both the five expert annotators and the suggested clustering algorithm. This gives us confidence that the proposed optimization method can be used in the future.
Molecular beam epitaxy of CdF2 layers on CaF2(111) and Si(111) (1994)

Cadmium fluoride single crystal layers have been grown on CaF2/Si(111) or Si(111) substrates by molecular beam epitaxy. The structures are expected to have attractive electronic properties. The growth was monitored by reflections high energy electron diffraction (RHEED) techniques. A distinct (√3×√3) R30° superstructure has been observed on the CdF2(111) surface at growth temperatures below 150 °C. RHEED intensity oscillations indicate a two-dimensional growth mode of CdF2.
Immunology of O-Glycosylated Proteins: Approaches to the Design of a MUC1 Glycopeptide-Based Tumor Vaccine (2006)

Until about 1990 there was general consent about the assumption that only protein and peptide antigens have the capacity of CD4(+) or CD8(+) T-cell stimulation. Since about ten years evidence is now accumulating that carbohydrate-peptide epitopes do play a role in classical MHC-mediated immune responses. This holds true for glycopeptides, where the glycan chain is short and not located at an "anchor residue" needed for MHC interaction. T-cell recognition of O-glycosylated peptides is potentially of high biomedical significance, because it can mediate the immune protection against microorganisms, the vaccination in anti-tumor therapies, but also some aspects of autoimmunity. The epithelial type 1 transmembrane mucin MUC1 is established as a marker for monitoring recurrence of breast cancer and is a promising target for immunotherapeutic strategies to treat cancer by active specific immunization. Natural human immune responses to the tumor-associated glycoforms of the mucin indicate that antibody reactivities are more directed to glycopeptide than to non-glycosylated peptide epitopes. To overcome the weak immunogenicity of the natural target, heavily O-glycosylated MUC1, the question was addressed whether O-linked glycans remain intact during processing in the MHC class II pathway and interfere with endosomal processing and peptide presentation. Attempts were made to define on a biochemical level the structural requirements for an efficient endosomal proteolysis catalyzed by cathepsin L in antigen-presenting cells. Evidence based on work with CD4(+) T-hybridomas confirms that O-glycopeptides can be effectively presented to T-cells and that glycans can form integral parts of the TCR defined epitopes. Similar approaches are currently followed in the MHC class I pathway which aim at the identification of immunogenic glycopeptides generated by immunoproteasomes.