gebhart/patrepeval huggingface dataset:
Deposition and properties of novel nitride superlattice coatings. Final report, May 1990--January 1996 (1996)

The authors have fulfilled the primary objectives of this research program which were to establish the feasibility of depositing polycrystalline nitride superlattices with high hardnesses on steel substrates, to understand the relationship between deposition process parameters, film microstructure, and resulting film properties, and to investigate the theories of superlattice strengthening/hardening. An opposed-cathode unbalanced magnetron sputtering system was modified for the deposition of the superlattices. Thin films of several microns thick, composed of many alternating thin layers of two (or more) different materials with periods between 3 and 150 nm, were deposited at low temperature onto various engineering substrate mate5rials such as steel. They have developed several superlattices with superior properties unattainable from either single-layer or thicker multilayer coatings. The nitride superlattices that they have explored so far include TiN/NbN, TiN/VN, NbN/VN, TiN/CrN, AlN/TiN, TiN/Ni, and TiN/NiCr. The effects of deposition parameters on film structure and properties were systematically studied, and optimized parameters for both monolithic films and superlattices were developed. The results of this research show that polycrystalline nitride superlattices have great promise for replacing commonly used nitride-based wear protective coatings. The existence of metastable crystalline phases has been observed in some of the superlattices explored, which they have named nanolayer-stabilized materials. The theoretical knowledge and experimental methods developed in this work have already been used to design and produce superlattice coatings for industrial work. A parallel industrial group program has been established to transfer the superlattice coating technology to industry. The detailed results achieved in this project have been discussed in over a dozen publications. The most important results from the work are summarized.
The Covert Liver Disease of Drug Addicts (1974)

Summary: Twenty young narcotic addicts who had been using drugs intravenously for at least two years were examined for the presence of liver disease. Eleven (55%) had abnormal liver function tests, and 19 (95%) had abnormal liver biopsies. Fourteen showed the changes of chronic persistent hepatitis. The remaining five showed in addition greatly expanded portal tracts with dense lymphoid aggregates and poorly formed histiocytic granulomas. Foreign material was identified in five biopsies. No patient had HB Ag in the serum, but four had detectable levels of HB Ab. It is concluded that the liver lesion is associated with the repeated intravenous injection of contaminated drug preparations, but no single causal agent, infective or chemical, has been clearly identified. Despite little biopsy evidence of progression, florid changes persist long after drug taking has stopped, so that a benign prognosis cannot be assured.
Chiral anomaly without Landau levels: From the quantum to the classical regime (2018)

We study the chiral anomaly in disordered Weyl semimetals, where the broken translational symmetry prevents the direct application of Nielsen and Ninomiya's mechanism and disorder is strong enough that quantum effects are important. In the weak disorder regime, there exist rare regions of the random potential where the disorder strength is locally strong, which gives rise to quasilocalized resonances and their effect on the chiral anomaly is unknown. We numerically show that these resonant states do not affect the chiral anomaly only in the case of a single Weyl node. At energies away from the Weyl point, or with strong disorder where one is deep in the diffusive regime, the chiral Landau level itself is not well defined and the semiclassical treatment is not justified. In this limit, we analytically use the supersymmetry method and find that the Chern-Simons term in the effective action which is not present in nontopological systems gives rise to a nonzero average level velocity which implies chiral charge pumping. We numerically establish that the nonzero average level velocity serves as an indicator of the chiral anomaly in the diffusive limit.
Photocarcinogenesis in mice by 4,4',6 trimethylangelicin plus UVA radiation. (1990)

The carcinogenic effect of a new monofunctional psoralen 4,4',6-trimethylangelicin (TMA) plus UVA radiation was examined in C3H/HeN mice and compared with that of the parent compound angelicin. TMA carcinogenic effects were also compared with the previously reported effects of 8-methoxypsoralen. Using 2 different doses of TMA (25 micrograms and 250 micrograms) combined with 1 J/cm2 of UVA radiation, we found that 42% and 52% of the mice (respectively) developed tumors on the treated site. A dose of angelicin (215 micrograms) equimolar to the highest dose of TMA combined with 1 J/cm2 of UVA radiation produced tumors in 28% of the mice (P greater than 0.05). All tumors were squamous cell carcinomas. No metastases were found in any of the mice. We conclude that, although TMA + UVA radiation is carcinogenic in mice, it seems to be an equally active, but less phototoxic and less carcinogenic psoralen than 8-methoxypsoralen. The parent compound angelicin is not significantly less carcinogenic, and its clinical efficacy is poor.
Connexin 43 Hemichannels Are Permeable to ATP (2008)

Astrocytes are electrically nonexcitable cells that communicate by means of Ca(2+) signaling. Long-distance intercellular Ca(2+) waves are initiated by release of ATP and activation of purinergic receptors on nearby cells. Previous studies have implicated connexin 43 (Cx43) in ATP release, but definitive proof that ATP exits through Cx43 hemichannels does not exist. Here, through several alternative approaches, we show that ATP anions can permeate through Cx43 hemichannels. First, openings of Cx43 hemichannels were detected in both cell-attached and inside-out patch recordings in C6 cells expressing Cx43, but not in C6 cells expressing Cx43-eGFP (enhanced green fluorescent protein) or a C-terminus truncation mutant of Cx43. Second, Cx43 hemichannel openings were inhibited by three structurally different gap-junction channel blockers, but not by the P2X(7) blocker Brilliant blue G. Third, bioluminescence imaging of ATP combined with single-channel recording in the inside-out patch configuration showed that ATP efflux coincided with channel openings and was absent when the Cx43 hemichannel was closed. Fourth, ion replacement experiments confirmed that Cx43 hemichannels are permeable to ATP. In summary, these observations provide the first direct evidence for efflux of ATP through Cx43 hemichannels. Furthermore, a putative Cx43 hemichannel with characteristics identical to the Cx43 hemichannel in C6 cells was identified in the membrane of hippocampal astrocytes in acutely prepared slices.
Supporting ethnographic studies of ubiquitous computing in the wild (2006)

Ethnography has become a staple feature of IT research over the last twenty years, shaping our understanding of the social character of computing systems and informing their design in a wide variety of settings. The emergence of ubiquitous computing raises new challenges for ethnography however, distributing interaction across a burgeoning array of small, mobile devices and online environments which exploit invisible sensing systems. Understanding interaction requires ethnographers to reconcile interactions that are, for example, distributed across devices on the street with online interactions in order to assemble coherent understandings of the social character and purchase of ubiquitous computing systems. We draw upon four recent studies to show how ethnographers are replaying system recordings of interaction alongside existing resources such as video recordings to do this and identify key challenges that need to be met to support ethnographic study of ubiquitous computing in the wild.
Mixed-level modeling in VHDL using the watch-and-react interface (2002)

Using VHDL, it is possible to model systems at many different levels of detail. The various modeling levels (performance, behavioral, etc.) can also be intermixed to create mixed-level models. The paper describes the watch-and-react interface which was created to resolve the differences in timing and data abstraction between the performance modeling domain (token based) and the behavioral modeling domain (value based). Specifically this interface is useful for integrating behavioral models of complex sequential components into performance models. It operates by monitoring the "important" signals in a system and then reacting to changes in these signals by generating tokens or forcing signals to appropriate values given the particular situation. The two main elements in the interface are the trigger and the driver. Program files containing scripting instructions are interpreted by the these two elements as the VHDL model simulates.
Influence of pressure and radio frequency power on deposition rate and structural properties of hydrogenated amorphous silicon thin films prepared by plasma deposition (1991)

The influence of radio frequency (rf) power and pressure on deposition rate and structural properties of hydrogenated amorphous silicon (a-Si:H) thin films, prepared by rf glow discharge decomposition of silane, have been studied by phase modulated ellipsometry and Fourier transform infrared spectroscopy. It has been found two pressure regions separated by a threshold value around 20 Pa where the deposition rate increases suddenly. This behavior is more marked as rf power rises and reflects the transition between two rf discharges regimes (α and γ). The best quality films have been obtained at low pressure and at low rf power but with deposition rates below 0.2 nm/s. In the high pressure region, the enhancement of deposition rate as rf power increases first gives rise to a reduction of film density and an increase of content of hydrogen bonded in polyhydride form because of plasma polymerization reactions. Further rise of rf power leads to a decrease of polyhydride bonding and the material density remains unchanged, thus allowing the growth of a-Si:H films at deposition rates above 1 nm/s without any important detriment of material quality. This overcoming of deposition rate limitation has been ascribed to the beneficial effects of ion bombardment on the a-Si:H growing surface by enhancing the surface mobility of adsorbed reactive species and by eliminating hydrogen bonded in polyhydride configurations.
Retrieving neuronal orientations using 3D scanning SAXS and comparison with diffusion MRI (2019)

While diffusion MRI (dMRI) is currently the method of choice to non-invasively probe tissue microstructure and study structural connectivity in the brain, its spatial resolution is limited and its results need structural validation. Current ex vivo methods employed to provide 3D fiber orientations have limitations, including tissue-distorting sample preparation, small field of view or inability to quantify 3D fiber orientation distributions. 3D fiber orientation in tissue sections can be obtained from 3D scanning small-angle X-ray scattering (3D sSAXS) by analyzing the anisotropy of scattering signals. Here we adapt the 3D sSAXS method for use in brain tissue, exploiting the high sensitivity of the SAXS signal to the ordered molecular structure of myelin. We extend the characterization of anisotropy from vectors to tensors, employ the Funk-Radon-Transform for converting scattering information to real space fiber orientations, and demonstrate the feasibility of the method in thin sections of mouse brain with minimal sample preparation. We obtain a second rank tensor representing the fiber orientation distribution function (fODF) for every voxel, thereby generating fODF maps. Finally, we illustrate the potential of 3D sSAXS by comparing the result with diffusion MRI fiber orientations in the same mouse brain. We show a remarkably good correspondence, considering the orthogonality of the two methods, i.e. the different physical processes underlying the two signals. 3D sSAXS can serve as validation method for microstructural MRI, and can provide novel microstructural insights for the nervous system, given the method's orthogonality to dMRI, high sensitivity to myelin sheath's orientation and abundance, and the possibility to extract myelin-specific signal and to perform micrometer-resolution scanning.
On Borrowed Ground (2009)

The Oconto to Peshtigo Project was an undertaking of the Northeast Region of the Wisconsin Department of Transportation which converted a heavily traveled two-lane highway between Oconto and Peshtigo into a four-lane expressway with freeway bypasses around each of the cities. In completing this project, 200 acres of wetland habitat were lost. An additional 300 acres of suitable land were either bought or leased to convert to wetlands as a result. This is especially important since the wetlands between the cities of Green Bay and Marinette serve as the best spawning areas for northern pike in the Green Bay watershed. The unique challenges contractors found in each of the three geographical areas the project encompassed are discussed by the author.
Singlet state photochemistry of dibenzyl ketone and its o-tolyl derivatives (1993)

The singlet state contribution of α-cleavage in the photochemistry of dibenzyl ketone (DBK) and o-tolylmethyl benzyl ketone (TBK) was investigated. The fitting of a master Stern—Volmer equation for the simultaneous quenching of the S1 and T1 states of DBK and TBK leads to the conclusion that in both ketones α-cleavage occurs in the singlet state, but to a lesser (20%–30%) extent than in the triplet. Comparison of the relative fluorescence and α-cleavage quantum yields of DBK and TBK is also consistent with the presence of singlet state α-cleavage in both ketones. The introduction of a methyl group in the ortho position of the phenyl ring in TBK introduces a second singlet state ketone reaction, δ-hydrogen-atom abstraction. This reaction is faster than α-cleavage in the S1 state, but proceeds with a low quantum efficiency. A δ-hydrogen-atom-induced internal conversion is proposed to be a major mechanism for the deactivation of the S1 state of TBK. This deactivation of S1 serves to reduce the efficiency of intersystem crossing and competes effectively with α-cleavage in S1. For TBK, o,o′-dimethyl TBK and mesitylmethyl benzyl ketone, which all show fast singlet state hydrogen-atom abstraction, the quantum yields of fluorescence and α-cleavage decrease. On the basis of the assumption of a certain (20%) participation of singlet state α-cleavage and fast δ-hydrogen-atom abstraction, a general mechanism and rate constants of each process were estimated for DBK and TBK.
Supercritical speedup (discrete event simulation) (1991)

The notions of the critical path of events and critical time of an event are key concepts in analyzing the performance of a parallel discrete event simulation. The highest critical time of any event in a simulation is a lower bound on the time it takes to execute a simulation using any conservative simulation mechanism, and is also a lower bound on the time taken by some optimistic methods. However, at least one optimistic mechanism is able to beat the critical path bound in a nontrivial way. The authors make a systematic study of the meaning of the critical path in parallel simulation, and describe criteria that determine when a simulation is bounded by its length and when it is not. They show (again) that no conservative mechanism can beat the critical path, but that at least four known optimistic mechanisms are all capable of supercritical speedup. They give performance data for the JPL Time Warp operating system showing two specially constructed applications using different methods to beat the critical path.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
General Synthesis of Tributary Switching Networks (1963)

A synthesis procedure is described which generates all tributary networks (TRIBs) realizing a given truth function when no a priori assignment of the variables to input terminals is specified. If the truth function is not known to be realizable by a TRIB structure, the synthesis procedure provides a convenient test for TRIB realizability. If the variables are preassigned to input terminals, the synthesis and test are still applicable and correspondingly shorter. A major tool of the procedure is the matrix of binary representations of the minterms of the truth function-the so called ``minterm matrix.'' The procedure is illustrated by a numerical example.
Dehiscence and fenestration in patients with different vertical growth patterns assessed with cone-beam computed tomography (2012)

The null hypothesis was rejected. Although the prevalence of fenestrations was not different, significant differences for dehiscences were found in patients with different vertical growth patterns.
What does the marriage of Open Access with online publication bring? (2004)

Open Access online publishing is the trend of the future for unrestricted rapid and international dissemination of knowledge. Several journals are published on acquired immune deficiency syndrome (AIDS) research, but none of them appear to be Open Access. To eliminate or to abate the scourge of AIDS, it is important that the knowledge acquired through research be disseminated as soon as possible. The Open Access journal, AIDS Research and Therapy, is intended to fill this knowledge gap by online publication of basic, preclinical, and clinical research articles.
An Artifact in LC-MS/MS Measurement of Glutamine and Glutamic Acid: In-Source Cyclization to Pyroglutamic Acid (2014)

Advances in metabolomics, particularly for research on cancer, have increased the demand for accurate, highly sensitive methods for measuring glutamine (Gln) and glutamic acid (Glu) in cell cultures and other biological samples. N-terminal Gln and Glu residues in proteins or peptides have been reported to cyclize to pyroglutamic acid (pGlu) during liquid chromatography (LC)-mass spectrometry (MS) analysis, but cyclization of free Gln and Glu to free pGlu during LC-MS analysis has not been well-characterized. Using an LC-MS/MS protocol that we developed to separate Gln, Glu, and pGlu, we found that free Gln and Glu cyclize to pGlu in the electrospray ionization source, revealing a previously uncharacterized artifact in metabolomic studies. Analysis of Gln standards over a concentration range from 0.39 to 200 μM indicated that a minimum of 33% and maximum of almost 100% of Gln was converted to pGlu in the ionization source, with the extent of conversion dependent on fragmentor voltage. We conclude that the sensitivity and accuracy of Gln, Glu, and pGlu quantitation by electrospray ionization-based mass spectrometry can be improved dramatically by using (i) chromatographic conditions that adequately separate the three metabolites, (ii) isotopic internal standards to correct for in-source pGlu formation, and (iii) user-optimized fragmentor voltage for acquisition of the MS spectra. These findings have immediate impact on metabolomics and metabolism research using LC-MS technologies.
ChemInform Abstract: CHARACTERIZATION AND REACTION KINETICS OF INTERMEDIATES PRODUCED IN THE PHOTOLYSIS OF M(CO)6 (M = CR, MO, W) SOLUTIONS CONTAINING A 1,4‐DIAZABUTADIENE LIGAND (1985)

Abstract Elektronenabsorptionsspektren zeigen bei der Photolyse der Metallcarbonyle in Benzol in Gegenwart von 1,4‐Di‐tert.‐butyl‐1,4‐diazabutadien die rasche Bildung eines primären Reaktionsintermediäres, das als eine Solvens‐verunreinigte Spezies erkannt wird.
Low Power, High Dynamic Range CMOS Image Sensor Employing Pixel-Level Oversampling <formula formulatype="inline"> <tex Notation="TeX">$\Sigma\Delta$</tex> </formula> Analog-to-Digital Conversion (2011)

We present a theoretical analysis, design, and experimental characterization of a CMOS image sensor with pixel-level ΣΔ oversampling analog-to-digital conversion (ADC). The design employs five transistors per-pixel to implement a charge-based ΣΔ ADC at each pixel. In the current design a dynamic regenerative latch comparator is divided into an input transistor, which is contained within each pixel, and the remaining comparator structure shared among the pixels of each column. A charge feedback digital-to-analog converter (DAC) is implemented at each pixel with a three-transistor structure. As opposed to more traditional CMOS image sensors, this image sensor architecture is suitable for implementations in advanced low supply voltage CMOS technologies since its dynamic range is not affected by the reduction of the pixel reset voltage. In addition, similar to the readout methods in low power random access memory designs, this pixel readout architecture does not employ any active amplifiers which allows for low static power operation. Experimental characterization of a prototype fabricated in a 0.35 μm silicided CMOS technology is presented. The estimated power consumption of the fully integrated 128 × 128 imager including decimation filters and I/O interface is 60 nW/pixel at 30 frames per second for 8-bits per-pixel. A peak signal-to-noise ratio of 52 dB and intra-scene dynamic range of 74 dB were measured. The dynamic range was extended to 91 dB through control of the in-pixel DAC supply voltage over the range of 0.8 V-3.3 V.