gebhart/patrepeval huggingface dataset:
Etude par microscopie électronique en transmission in situ de la plasticité en conditions cryogéniques de deux microstructures de l’alliage Ti-6A1-4V (1996)

L’objectif de cette étude est de clarifier le rôle de la microstructure sur le comportement mécanique de l’alliage Ti-6AI-4V en conditions cryogéniques. Deux microstructures ayant des propriétés mécaniques différentes sont étudiées. La microstructure I est principalement constituée de grains a et de colonies de fines aiguilles α’ et la microstructure II de grains α et de colonies de larges lamelles α secondaire. La microstructure I a une limite d’élasticité plus élevée que la microstructure II, mais une ductilité plus faible à 20 K. Les mécanismes de déformation de chacun des constituants des deux microstructures I et II ont été étudiés par microscopie électronique en transmission in situ à 15 K et à partir d’observations post mortem d’éprouvettes déformées à 20 ou 300 K.
Dual-Family Peptidylprolyl Isomerases (Immunophilins) of Select Monocellular Organisms (2018)

The dual-family peptidylprolyl cis-trans isomerases (immunophilins) represent naturally occurring chimera of classical FK506-binding protein (FKBP) and cyclophilin (CYN), connected by a flexible linker, and are found exclusively in monocellular organisms. The modular builds of these molecules represent two distinct types: CYN-(linker)-FKBP and FKBP-3TPR-CYN. Abbreviated respectively as CFBP and FCBP, the two classes also exhibit distinct organism preference, the CFBP being found in prokaryotes, and FCBP, in eukaryotes. This review summarizes the mystery of these unique class of prolyl isomerases, focusing on their host organisms, potential physiological role, and likely routes of evolution.
Impact of energy function on a neural network model for optimization problems (2002)

A neural network model for the solution of optimization problems is studied in this paper. Six different variations of the energy function that governs this network are presented and extensively evaluated. In order to evaluate these energy functions the traveling salesman problem has been used. The evaluation consists of measuring (over a large number of simulations) the following parameters: number of times that the network converges to a valid solution, quality of generated solution, and the number of network update cycles to reach a solution.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>
ChemInform Abstract: General Approach for the Synthesis of Macroline/Sarpagine Related Indole Alkaloids via the Asymmetric Pictet‐Spengler Reaction: The Enantiospecific Synthesis of the Na‐H, Azabicyclo(3.3.1)nonanone Template. (1997)

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Vision and Requirements of the Wireless World (2006)

This chapter contains sections titled: What we are Observing Today in 2005 What is on the Way for 2010? Projection for 2017 Acknowledgement
Plasmin degradation of insulin-like growth factor-binding protein-5 (IGFBP-5): regulation by IGFBP-5-(201—218) (1997)

Using the major bone insulin-like growth factor-binding protein (IGFBP) IGFBP-5, we took a mechanistic approach in evaluating the role of the heparin-binding domain of IGFBP-5 in regulating plasmin (Pm) proteolysis of IGFBP-5. Using synthetic IGFBP-5 peptide fragments, we determined that the heparin-binding domain, IGFBP-5-(208-218), inhibits Pm proteolysis of intact IGFBP-5. The mechanism of action of IGFBP-5-(201-218) was by inhibiting Pm binding to substrate IGFBP-5. IGFBP-5-(201-218) action was independent of site of proteolysis, fluid, or solid phase interaction. In addition, IGFBP-5-(201-218) was found to inhibit plasminogen (Pg) activation to Pm IGFBP-5-(201-218) did not directly inhibit the activity of Pm, urokinase Pg activator (PA), or tissue-type PA but acted as a competitive inhibitor of Pg activation by PA, which is in contrast to the stimulating effect of heparin on Pg activation. These data indicate that the heparin-binding domain contains the serine protease (Pg-to-Pm) binding site region of IGFBP-5, and that this region, which is presumed to represent a Pm-induced proteolytic product of IGFBP-5, is capable of regulating Pm action.
Abnormal electrical resistivity in γ-TiAl thin films deposited by magnetron sputtering (2003)

Thin films of γ-TiAl are being considered as a potential conductor and/or diffusion barrier for high temperature electronics because of their high melting points and high oxidation resistance. However, it is not possible to form pure γ-TiAl thin films by thermal annealing of Al/Ti bilayers. This study, however, demonstrates the formation of γ-TiAl thin films by dc magnetron sputtering of a compound target. X-ray diffractometry and Rutherford backscattering spectrometry analyses confirm the γ-TiAl phase formation, composition, and thermal stability in vacuum (up to 700 °C, 1 h) on SiO2. Four-point probe resistivity measurements in vacuum show an initial increase in the resistivity with temperature up to transition temperature for the γ-TiAl thin films. At higher temperatures a decrease in resistivity with additional heating (i.e., negative temperature coefficient of resistivity, TCR) is seen. The values of dρ/dT are typically on the order of −0.32 μΩ cm/°C between 200 and 550 °C. At the highest temperature, a minimum value of resistivity of ∼13 μΩ cm is obtained; this value is about one half the value of bulk TiAl at room temperatures. The negative TCR, low resistivity values at high temperatures, and temperature stability are not typically seen in bulk TiAl. This abnormal electrical property is explained using a modified model for a thermally activated polaron-hopping mechanism.
Spatiotemporal light control with active metasurfaces (2019)

Optical metasurfaces have provided us with extraordinary ways to control light by spatially structuring materials. The space-time duality in Maxwell's equations suggests that additional structuring of metasurfaces in the time domain can even further expand their impact on the field of optics. Advances toward this goal critically rely on the development of new materials and nanostructures that exhibit very large and fast changes in their optical properties in response to external stimuli. New physics is also emerging as ultrafast tuning of metasurfaces is becoming possible, including wavelength shifts that emulate the Doppler effect, Lorentz nonreciprocity, time-reversed optical behavior, and negative refraction. The large-scale manufacturing of dynamic flat optics has the potential to revolutionize many emerging technologies that require active wavefront shaping with lightweight, compact, and power-efficient components.
Spontaneous Emission Control of CdSe/ZnS Nanoparticle Monolayer in Polymer Nanosheet Waveguide Assembled on a One-Dimensional Silver Grating Surface (2012)

We present spontaneous emission control of a core-shell CdSe/ZnS nanoparticle array assembled with polymer ultrathin films consisting of polymer nanosheets on a silver grating substrate, which served as a unique and simple photonic cavity. The grating-coupled waveguide modes enabled 10(3) order luminescence enhancement and one-fourth spectral narrowing. The light emission from a CdSe/ZnS nanoparticle array can be controlled by tuning the film thickness of hybrid polymer nanoassemblies, which provides multiple emission performance with good tuning ability from red to green at low-power continuous wave laser excitation (∼μW).
A fully integrated 28nm Bluetooth Low-Energy transmitter with 36% system efficiency at 3dBm (2015)

We propose a new transmitter (TX) architecture for ultra-low power radios. An all-digital PLL employs a digitally controlled oscillator with switching current sources to reduce supply voltage and power without sacrificing its phase noise and startup margins. It also reduces 1/f noise allowing the ADPLL, after settling, to reduce its sampling rate or shut it off entirely during direct DCO data modulation. The switching power amplifier integrates its matching network while operating in class-E/F <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> to maximally enhance its efficiency. The transmitter is realized in 28nm CMOS and satisfies all metal density and other manufacturing rules. It consumes 3.6 mW/5.5mW while delivering 0dBm/3 dBm RF power in Bluetooth Low-Energy.
Combining text summarization and aspect-based sentiment analysis of users' reviews to justify recommendations (2019)

In this paper we present a methodology to justify recommendations that relies on the information extracted from users' reviews discussing the available items. The intuition behind the approach is to conceive the justification as a summary of the most relevant and distinguishing aspects of the item, automatically obtained by analyzing its reviews. To this end, we designed a pipeline of natural language processing techniques including aspect extraction, sentiment analysis and text summarization to gather the reviews, process the relevant excerpts, and generate a unique synthesis presenting the main characteristics of the item. Such a summary is finally presented to the target user as a justification of the received recommendation. In the experimental evaluation we carried out a user study in the movie domain (N=141) and the results showed that our approach is able to make the recommendation process more transparent, engaging and trustful for the users.
A signal processing approach for effective reduction of timing jitter due to the acoustic effect (2002)

We introduce a signal processing approach to compensate for the timing jitter produced by the acoustic effect in soliton communications. The other main sources of timing jitter, the Gordon-Haus effect and the polarization effect, are inherently stochastic. By contrast, the acoustic effect is deterministic and becomes the dominant source of bit error rates in standard soliton systems when the bit rates are more than 10 Gbits/s and the transmission distance is more than several thousand kilometers. We exploit the deterministic nature of the acoustic effect to introduce a scheme that predicts the amount of timing jitter as a function of the previous transmitted bits and uses the information to adjust the sampling period of the received soliton pulses. We demonstrate successful application of the scheme by simulations and discuss implementation issues.
Performance of Electronic Dispersion Compensation for Multi-Level Modulation Formats using Homodyne Coherent Detection (2006)

We investigate numerically the performance of electronic dispersion compensation with linear transversal filters of different filter lengths and tap delays for RZ-DQPSK, RZ-8-DPSK and star RZ-16-DQAM after homodyne coherent detection at 10.7 Gsymbols/s.
Measured Diversity Gains from MIMO Antenna Selection (2006)

We investigate the diversity gain of MIMO systems with antenna selection in measured propagation channels for wireless personal area networks. We measure both the communication from an access point to a laptop, and between two handheld devices. Both the transmitter and receiver use antenna selection for diversity transmission and reception. We consider a closed-loop system where the transmitter has full channel state information, and analyze a number of different antenna selection algorithms and signal combining methods. We find that line of sight (LOS) and non-line of sight (NLOS) situations have fairly similar behavior, and that different polarizations result in similar SNR gains. We also find that RF-preprocessing of the signals is less effective for the hand held devices scenario than for the access point and laptop scenario. Finally, we compare bulk selection (same antenna subset is used for all frequency sub-channels) to per-tone selection (different antenna subsets can be used for each frequency sub-channel) for a wideband channel.
Convergent Evolution of HLA-C Downmodulation in HIV-1 and HIV-2 (2020)

HLA-C-mediated antigen presentation induces the killing of human immunodeficiency virus (HIV)-infected CD4<sup>+</sup> T cells by cytotoxic T lymphocytes (CTLs). To evade killing, many HIV-1 group M strains decrease HLA-C surface levels using their accessory protein Vpu. However, some HIV-1 group M isolates lack this activity, possibly to prevent the activation of natural killer (NK) cells. Analyzing diverse primate lentiviruses, we found that Vpu-mediated HLA-C downregulation is not limited to pandemic group M but is also found in HIV-1 groups O and P as well as several simian immunodeficiency viruses (SIVs). We show that Vpu targets HLA-C primarily at the protein level, independently of its ability to suppress NF-κB-driven gene expression, and that in some viral lineages, HLA-C downregulation may come at the cost of efficient counteraction of the restriction factor tetherin. Remarkably, HIV-2, which does not carry a <i>vpu</i> gene, uses its accessory protein Vif to decrease HLA-C surface expression. This Vif activity requires intact binding sites for the Cullin5/Elongin ubiquitin ligase complex but is separable from its ability to counteract APOBEC3G. Similar to HIV-1 Vpu, the degree of HIV-2 Vif-mediated HLA-C downregulation varies considerably among different virus isolates. In agreement with opposing selection pressures <i>in vivo</i>, we show that the reduction of HLA-C surface levels by HIV-2 Vif is accompanied by increased NK cell-mediated killing. In summary, our results highlight the complex role of HLA-C in lentiviral infections and demonstrate that HIV-1 and HIV-2 have evolved at least two independent mechanisms to decrease HLA-C levels on infected cells.<b>IMPORTANCE</b> Genome-wide association studies suggest that HLA-C expression is a major determinant of viral load set points and CD4<sup>+</sup> T cell counts in HIV-infected individuals. On the one hand, efficient HLA-C expression enables the killing of infected cells by cytotoxic T lymphocytes (CTLs). On the other hand, HLA-C sends inhibitory signals to natural killer (NK) cells and enhances the infectivity of newly produced HIV particles. HIV-1 group M viruses modulate HLA-C expression using the accessory protein Vpu, possibly to balance CTL- and NK cell-mediated immune responses. Here, we show that the second human immunodeficiency virus, HIV-2, can use its accessory protein Vif to evade HLA-C-mediated restriction. Furthermore, our mutational analyses provide insights into the underlying molecular mechanisms. In summary, our results reveal how the two human AIDS viruses modulate HLA-C, a key component of the antiviral immune response.
Microscopic observation of bacteria: review highlighting the use of environmental SEM (2005)

Throughout the years, various methods have been adopted to investigate bacteria involved in root canal infection and apical periodontitis. This paper reviews the most commonly used microscopic techniques and discusses their possibilities, limitations and sample preparation. In particular, a recently developed variant of scanning electron microscope (SEM), referred to as environmental SEM (ESEM), is highlighted due to its potential impact across the diverse field of biomaterials research. The performance of this ESEM technique for bacterial observation of endodontic pathogens was illustrated by a practical approach. The paper concludes with a discussion on the possible use of ESEM for testing endodontic treatment modalities under environmental conditions in situ.
Cognitive Aeronautical Communication System (2011)

The paper explores the system and architecture requirements for cognitive driven reconfigurable hardware for an aeronautical platform, such as commercial aircraft or high altitude platforms. With advances in components and processing hardware, mobile platforms are ideal candidates to have configurable hardware that can morph itself, given the location and available wireless service. This paper proposes a system for an intelligent self-configurable software and hardware solution for an aeronautical system.
Mobile genetic elements and genome evolution 2014 (2014)

The Mobile Genetic Elements and Genome Evolution conference was hosted by Keystone Symposia in Santa Fe, NM USA, 9 March through 14 March 2014. The goal of this conference was to bring together scientists from around the world who study transposable elements in diverse organisms and researchers who study the impact these elements have on genome evolution. The meeting included over 200 scientists who participated through poster presentations, short talks selected from abstracts, and invited speakers. The talks were organized into eight sessions and two workshops. The topics varied from diverse mechanisms of mobilization to the evolution of genomes and their defense strategies against transposable elements.
Particle generation in a chemical vapor deposition process with seed particles (1990)

Abstract The formation of aerosol particles by gas‐phase chemical reaction in the presence of seed particles has been studied experimentally and theoretically. Titanium tetraisopropoxide (TTIP) vapor containing ultrafine TiO 2 seed particles was introduced into a laminar flow aerosol reactor, and the properties of produced TiO 2 aerosol were measured. By comparing the particle numbers and size distributions of the resulting aerosol with those of the seed particles and those of homogeneously nucleated particles in the absence of seed particles, the effects of initial concentrations of TTIP vapor, reaction temperatures, and properties of seed particles on the suppression of homogeneous nucleation were experimentally clarified. In the theoretical analysis, the population balance equation expressing simultaneous generation of TiO 2 monomer, Brownian coagulation and diffusive deposition of TiO 2 monomer and aerosols was solved. The observed suppression of homogeneous nucleation by the seed particles is explained qualitatively by the theoretical analysis.
Airborne system for multispectral, multiangle polarimetric imaging (2015)

In this paper, we describe the design, fabrication, calibration, and deployment of an airborne multispectral polarimetric imager. The motivation for the development of this instrument was to explore its ability to provide information about water constituents, such as particle size and type. The instrument is based on four 16 MP cameras and uses wire grid polarizers (aligned at 0°, 45°, 90°, and 135°) to provide the separation of the polarization states. A five-position filter wheel provides for four narrow-band spectral filters (435, 550, 625, and 750 nm) and one blocked position for dark-level measurements. When flown, the instrument is mounted on a programmable stage that provides control of the view angles. View angles that range to ±65° from the nadir have been used. Data processing provides a measure of the polarimetric signature as a function of both the view zenith and view azimuth angles. As a validation of our initial results, we compare our measurements, over water, with the output of a Monte Carlo code, both of which show neutral points off the principle plane. The locations of the calculated and measured neutral points are compared. The random error level in the measured degree of linear polarization (8% at 435) is shown to be better than 0.25%.
Steering Interzeolite Conversion with Alkali Metal Cations: Lithium Maximizes Al Proximity in SSZ-13 Zeolite Genesis (2022)

Zeolites have long been regarded as difficult to modify during synthesis, as their synthesis is governed by kinetic processes. Recent breakthroughs have made it possible to exert a certain degree of control over zeolite properties with more performant materials as a result. Here, we investigate the effects alkali cations have on high-silica FAU-to-CHA interzeolite conversion (IZC) and on the resulting aluminum distributions. In this way, by using Li-cations in conjunction with an organic structure directing agent, the first route to a “fully paired” (divalent cation capacity, Co2+/Al = 0.48) high-silica SSZ-13 zeolite is demonstrated. Lithium shows great potential in steering IZC synthesis as it speeds up crystallization, and evidence was gathered in favor of a more elaborate mechanism of IZC in which dissolved Al-rich oligomers crash out of solution first and possibly spark nucleation. These findings help in gaining insights into a more general theory on zeolite nucleation in heterogeneous environments such as IZC. Furthermore, the “fully paired” sample has great potential for ion-exchanged zeolite catalysis or in adsorbents.
Plasmon-controlled fluorescence: a new detection technology (2006)

Fluorescence is widely used in biological research. Future advances in biology and medicine often depend on the advances in the capabilities of fluorescence measurements. In this overview paper we describe how a combination of fluorescence, and plasmonics, and nanofabrication can fundamentally change and increase the capabilities of fluorescence technology. This change will be based on the use of surface plasmons which are collective oscillations of free electrons in metallic surfaces and particles. Surface plasmon resonance is now used to measure bioaffinity reactions. However, the uses of surface plasmons in biology are not limited to their optical absorption or extinction. We have shown that fluorophores in the excited state can create plasmons which radiate into the far field; additionally fluorophores in the ground state can interact with and be excited by surface plasmons. These interactions suggest that the novel optical absorption and scattering properties of metallic nanostructures can be used to control the decay rates, location and direction of fluorophore emission. We refer to this technology as plasmon-controlled fluorescence. We predict that plasmon-controlled fluorescence (PCF) will result in a new generation of probes and devices. PCF is likely to allow design of structures which enhance emission at specific wavelengths and the creation of new devices which control and transport the energy from excited fluorophores in the form of plasmons, and then convert the plasmons back to light.
Biochemical transport modeling, estimation and detection in realistic environments (2006)

Early detection and estimation of the spread of a biochemical contaminant are major issues for homeland security applications. We present an integrated approach combining the measurements given by an array of biochemical sensors with a physical model of the dispersion and statistical analysis to solve these problems and provide system performance measures. We approximate the dispersion model of the contaminant in a realistic environment through numerical simulations of reflected stochastic diffusions describing the microscopic transport phenomena due to wind and chemical diffusion using the Feynman-Kac formula. We consider arbitrary complex geometries and account for wind turbulence. Localizing the dispersive sources is useful for decontamination purposes and estimation of the cloud evolution. To solve the associated inverse problem, we propose a Bayesian framework based on a random field that is particularly powerful for localizing multiple sources with small amounts of measurements. We also develop a sequential detector using the numerical transport model we propose. Sequential detection allows on-line analysis and detecting wether a change has occurred. We first focus on the formulation of a suitable sequential detector that overcomes the presence of unknown parameters (e.g. release time, intensity and location). We compute a bound on the expected delay before false detection in order to decide the threshold of the test. For a fixed false-alarm rate, we obtain the detection probability of a substance release as a function of its location and initial concentration. Numerical examples are presented for two real-world scenarios: an urban area and an indoor ventilation duct.