gebhart/patrepeval huggingface dataset:
Development of an MR-compatible gamma probe for combined MR/RI guided surgery (2004)

We have developed and tested an MR-compatible gamma probe to simultaneously obtain anatomical information and functional information during surgery. The probe consists of a probe head, an optical fibre bundle and a photo-multiplier tube (PMT). The NaI(T1) scintillator contained in the probe head is connected to a 7 m optical fibre bundle that transfers the scintillation photons produced in the NaI(T1) to an area of low magnetic field or out of the MR-scanner's magnetic shielded room. Although the light loss due to the optical fibre bundle was more than 90%, the photo-peak of the gamma for Co-57 (122 keV) could be observed. The point spread function was 4.5 mm full width at half maximum (FWHM) at 5 mm from the collimator surface for 122 keV gamma photons. Furthermore, there was no sensitivity change outside the MR-scanner, inside the MR-scanner without scanning and inside the MR-scanner with scanning. The probe produced a small artefact on the phantom image of the MR-scanner due to the susceptibility difference of the alloy used for the collimator and the shield. However, the artefact was only limited to area surrounding the probe. These results indicate that the developed MR-compatible gamma probe will make it possible to realize the combined MR/RI guided surgery that provides surgeons with anatomical and RI distribution information simultaneously.
Comparison of extra electrons in colloidal n-type Al3+-doped and photochemically reduced ZnO nanocrystals (2012)

The "extra" electrons in colloidal n-type ZnO nanocrystals formed by aliovalent doping and photochemical reduction are compared. Whereas the two are similar spectroscopically, they show very different electron-transfer reactivities, attributable to their different charge-compensating cations (Al(3+)vs. H(+)).
Excitation power dependence of photoluminescence spectra of CdTe on InSb grown by molecular-beam epitaxy (2002)

We report a study on the photoluminescence (PL) characteristic of CdTe epitaxial film. The studied CdTe materials were grown on InSb [001] by molecular beam epitaxy (MBE). Low temperature (2 K) PL spectra were measured at different excitation power level while laser beam was focused on the same spot of the sample. From PL spectra, overlapping peaks from excitation transition, shallow and deep donor-acceptor-pair (DAP) transitions and longitudinal optical (LO) phonon replicas were observed.
Enabling High-speed Ultrasound Communication Through Thin Plates by Reverberation Suppression (2021)

In all digital communications, knowledge of the propagation channel between the transmitter and the receiver is essential. For transmitting of data through solid bodies, such as metal plates, pipe walls, etc., ultrasound is a viable alternative to radio communication and wired transmission. In ultrasound communication, the channel consists of two parts, the combined response of the transducers used as transmitter and receiver, and the impulse response of the propagation medium itself. For a thin plate with parallel surfaces, this results in a reverberating channel that significantly reduces the achievable bitrate if not handled properly. In this paper we show with simulations how the bit-error rate in Orthogonal Frequency Division Multiplexing (OFDM) communications, is affected by the reverberating nature of the plate, and how this can be overcome by the introduction of a channel shortening filter placed in front of the OFDM conventional receiver. The results show that this significantly reduces the bit-error rate, especially for thin plates. If the reverberations instead were to be compensated by the conventional channel equalization method in OFDM, we show that for the example in the simulations, the bitrate would drop by almost 25 %, from about 3.9 Mbit/s to about 2.9 Mbit/s.
Electric Field Immunity Test on Epoxy-Resin Capacitive Voltage Sensor in Smart Bushing (2022)

With the development of Smart Grids, unconventional voltage transformers known as Low Power are being widely deployed in medium voltage power networks for measurement and protection functions. Low power voltage transformers, referred to as voltage sensors, are prone to the parasitic coupling of electric fields which may disturb the voltage measurement. In this work, an electrical equivalent model of the voltage sensor embedded in Smart Bushing is suggested for estimating the immunity versus electric fields present in Gas Insulated Switchgears. In addition, a setup is designed to test the immunity under different scenarios.
Crystalline metamaterials for topological properties at subwavelength scales (2017)

The exciting discovery of topological condensed matter systems has lately triggered a search for their photonic analogues, motivated by the possibility of robust backscattering-immune light transport. However, topological photonic phases have so far only been observed in photonic crystals and waveguide arrays, which are inherently physically wavelength scaled, hindering their application in compact subwavelength systems. In this letter, we tackle this problem by patterning the deep subwavelength resonant elements of metamaterials onto specific lattices, and create crystalline metamaterials that can develop complex nonlocal properties due to multiple scattering, despite their very subwavelength spatial scale that usually implies to disregard their structure. These spatially dispersive systems can support subwavelength topological phases, as we demonstrate at microwaves by direct field mapping. Our approach gives a straightforward tabletop platform for the study of photonic topological phases, and allows to envision applications benefiting the compactness of metamaterials and the amazing potential of topological insulators.
Enhancement of polymer thermoresponsiveness and drug delivery across biological barriers by addition of small molecules (2023)

Thermoresponsive polymers that undergo sol-gel transitions in the physiological temperature range have been widely used in biomedical applications. However, some commercially and clinically available thermoresponsive materials, particularly poloxamer 407 (P407), have the significant drawback of insufficient gel strength, which limit their performance. Furthermore, co-delivery with some small molecules, including chemical permeation enhancers (CPEs) can further impair the physical properties of P407. Here, we have developed a thermoresponsive platform by combination of CPEs with the poloxamer P188 to enable gelation at physiological temperatures and enhance gel strength. P188 gels at 60 °C, which is far above the physiological range. In combination with limonene (LIM) and sodium dodecyl sulfate (SDS), P188 gels at ∼25 °C, a temperature that in useful for biomedical applications. Gelation behavior was studied by small angle neutron scattering (SANS) experiments, which identified micelle-to-cubic mesophase transitions with increasing temperature. Analysis of the SANS intensities revealed that P188 micelles became larger as LIM or SDS molecules were incorporated, making it easier to form a micellar gel structure. P188-3CPE (i.e., 2% LIM, 1% SDS and 0.5% bupivacaine (BUP)) had low viscosity at room temperature, facilitating administration, but rapidly gelled at body temperature. P188-3CPE enabled the flux of the antibiotic ciprofloxacin across the TM and completely eradicated otitis media from nontypable Haemophilus influenzae (<i>NTHi</i>) in chinchillas after a single administration.
Site-Selective Eu3+ Luminescence in the Monoclinic Phase of YSiO2N (2021)

Eu3+-doped YSiO2N phosphor was synthesized, and its crystal structure was analyzed by single-crystal X-ray and neutron powder diffraction techniques. The new crystal structure of YSiO2N with the monoclinic lattice (space group C2/c) composed of nonequivalent [YO6N2] dodecahedra was identified, and, in this structure, five different Y3+ sites take Ci or Cn symmetry. Based on the experimentally determined crystal structure, we characterized the luminescence properties of the Eu3+ ions with site-selective and time-resolved spectroscopy. The Eu3+ ions at the Y: Cn sites show intense 5D0 → 7F2 electric dipole luminescence peaking at 626 nm with a short lifetime (0.61 ms) due to the lack of inversion center. In the centrosymmetric Ci sites, the lifetime of the 5D0 level was quite long (5.51 ms), and the strongest three peaks are assigned to the 5D0 → 7F1 magnetic dipole transition instead of 5D0 → 7F2. The anomalous temperature dependence of the long lifetime for Eu3+: 5D0 at this Ci site at low temperatures suggests that the slow radiative rate can be influenced by the thermal distortion of centrosymmetry. The thermal quenching mechanism of the Eu3+: 5D0 luminescence at both sites is considered to be due to the charge transfer states related to the N3– ions in the [Eu3+O6N2] dodecahedra rather than the multiphonon relaxation mechanism. This study shows the potentials of Eu3+ luminescence in oxynitride coordination and provides new insights into the material design guidelines for near-UV excitable red phosphor activated with Eu3+ ions.
Collector Profile Design of SiGe-HBTs for Optimized Static and High-Frequency Performance (1995)

Experimental and numerical results on the leverage of a modified vertical collector profile on dc characteristics as well as on high-frequency performance of a SiGe-HBT are presented. It is shown that an increased collector doping near the base junction allows to improve essentially the saturation behavior in high-current mode compared to a flat low doped collector region. The additional doping peak retards the onset of the Kirk effect and the accumulation of charge carriers at the base-collector heterojunction while keeping the collector-base capacitances C CB relatively low. Both from experiments and numerical calculations by means of a non-local ionization model we realize that the additional doping peak does not deteriorate the breakdown behavior. The drop of transit frequencyf T and maximum oscillation frequency f max can be driven to higher collector current densities. Furthermore, the suggested doping profile is well suited to compensate the outdiffusion of boron doping from the base.
Modeling the respiratory chain and the oxidative phosphorylation (2013)

Die oxidative Phosphorylierung (OXPHOS) spielt eine zentrale Rolle im Energiestoffwechsel der Zelle. Sie besteht aus der Atmungskette, deren vier Enzymkomplexe einen Protonengradienten über die innere mitochondriale Membran aufbauen, und der ATP-Synthase, die diesen Gradienten zur Phosphorylierung von ADP zu ATP, der zelluläre Energieeinheit, nutzt. In der vorliegenden Arbeit wurde ein thermodynamisch konformes OXPHOS Modell erstellt, welches auf Differentialgleichungen basiert. Dazu wurden Gleichungen entwickelt, welche die Kinetiken jedes OXPHOS-Komplexes über weite Bereiche von Substrat- und Produktkonzentrationen sowie unterschiedlichster Werte des elektrochemischen Gradientens wiedergeben. Zunächst wurden für jeden Komplex der Atmungskette kinetische Messungen in Abwesenheit des Protonengradientens durchgeführt. Für deren Beschreibung erwiesen sich Gleichungen vom Typ Michaelis-Menten als adäquat; hierbei wurden verschiedene Gleichungstypen verglichen. Anschließend wurde der Einfluss des Protonengradientens auf die kinetischen Parameter so modelliert, dass physiologisch sinnvolle Raten in dessen Abhängigkeit erzielt werden konnten. Diese neuen Ratengleichungen wurden schließlich in ein OXPHOS Modell integriert, mit dem sich experimentelle Daten von Sauerstoffverbrauch, elektrischem Potential und pH-Werten sehr gut beschreiben ließen. Weiter konnten Inhibitor-Titrationskurven reproduziert werden, welche den Sauerstoffverbrauch in Abhängigkeit der relativen Hemmung eines OXPHOS-Komplexes darstellen. Dies zeigt, dass lokale Effekte auf globaler Ebene korrekt wiedergeben werden können. Das hier erarbeitete Modell ist eine solide Basis, um die Rolle der OXPHOS und generell von Mitochondrien eingehend zu untersuchen. Diese werden mit zahlreichen zellulären Vorgängen in Verbindung gebracht: unter anderem mit Diabetes, Krebs und Mitochodriopathien, sowie der Bildung von Sauerstoffradikalen, die im Zusammenhang mit Alterungsprozessen stehen.
LED headlight architecture that creates a high quality beam pattern independent of LED shortcomings (2005)

One of the most challenging applications for high brightness LEDs is in automotive headlights. Optical designs for a low or high beam headlights are plagued by the low flux and luminance of LEDs compared to HID or incandescent sources, by mechanical chip placement tolerances and by color and flux variations between different LEDs. Furthermore the creation of a sharp cutoff is very difficult without baffles or other lossy devices. We present a novel LED headlight design that addresses all of the above problems by mixing the light of several LEDs first in a tailored light guide called LED combiner, thereby reducing color and flux variations between different LEDs and illuminance and color variations across the LED surfaces. The LED combiner forms a virtual source tailored to the application. The illuminance distribution of this virtual source facilitates the generation of the desired intensity pattern by projecting it into the far field. The projection is accomplished by one refractive and one reflective freeform surface calculated by the 3D SMS method. A high quality intensity pattern shape and a very sharp cutoff are created tolerant to LED to optics misalignment and illuminance variations across the LED surface. A low and high beam design with more than 75% total optical efficiency (without cover lens) and performance as latest HID headlights have been achieved. Furthermore it is shown that the architecture has similar tolerance requirements as conventional mass produced headlights.
Intracellular events associated with inhibition of B cell activation by monoclonal antibodies to HLA class II antigens (1989)

We have investigated several aspects of the inhibitory effects of monoclonal antibodies (mAb) directed against MHC class II antigens in B cell activation/proliferation, using a panel of mAb specifically reactive with antigens encoded by HLA class II loci (DP, DQ, DR). All mAb except the anti-DP mAb inhibited significantly anti-mu plus B cell growth factor-induced DNA synthesis. Only one mAb, however, which was reactive with gene products of all three class II loci (DP, DQ, DR) inhibited anti-mu-induced DNA synthesis as well as c-myc mRNA expression. In addition, the same mAb inhibited the early events induced by anti-mu stimulation alone, including phosphatidylinositol turnover and elevation of [Ca2+]i. In contrast to previous findings in the murine system, none of the anti-MHC class II mAb used in this study increased the cAMP levels.
Power Loss at Directional Change in Dielectric Waveguides (1974)

Wave propagation in a single-mode dielectric waveguide that changes in direction is treated theoretically. The directional change is represented as a sequence of straight waveguide sections joined by sharp corners. Power is exchanged between guided and unguided modes at the corners. Numerical results for slab waveguides illustrate that the loss for either a gradual curve or a sequence of two or more corner bends oscillates as a function of the distance over which the directional change takes place.
New Perspectives for Watering Substrate-Based Root Modules in Microgravity in the Advanced Plant Habitat (APH) (2019)

The Advanced Plant Habitat (APH) was installed on the International Space Station (ISS) in October 2017. Following a successful EVT (Experiment Verification Test) study at Kennedy Space Center (KSC), using Arabidopsis lines with varying levels of lignin, two inaugural studies were carried out on ISS in 2018 under the same experimental design, with the corresponding ground controls at KSC. The APH for this study deploys a substrate-based root module designed for plant growth in microgravity. Upon experiment initiation (such as for the EVT), the root module is primed (liquid imbibition) by flooding the root zone to initiate seed germination and to remove air from the porous tubing and particulate media. In the APH ISS inaugural study, the speed of supplying water to initially dry media was found to adversely affect the overall moisture distribution within the root module in microgravity (but not at 1g). Non-destructive estimations of Arabidopsis plant growth were carried out by monitoring changes in rosette leaf area on a daily basis. These data indicated that the original priming procedure caused patchy moisture distribution that affected plant growth and survival. An improved methodology for priming the second root module of PH-01 was devised and implemented in the second experiment. Leaf area and color estimates suggested that the modified priming scheme improved moisture distribution and plant growth. These data, when compared with the EVT study, suggest that nondestructive measurements of plant growth can aid towards optimization of plant growth conditions in microgravity.
Inhibition of hepatic phosphoenolpyruvate carboxykinase by avian reticuloendotheliosis viruses. (1985)

Severe weight loss is associated with many malignant diseases of humans and animals. Avian reticuloendotheliosis viruses (RE viruses) induce runting in experimentally infected chickens. Chickens infected with a replication-competent RE virus, reticuloendotheliosis-associated virus, weighed 30-50% less than control birds at the time of death. Chickens infected with reticuloendotheliosis virus, a replication-defective acute leukemia virus, weighed 30% less than the controls. The runting induced by RE viruses does not occur because of reduced food intake. Activities of phosphoenolpyruvate carboxykinase, a key gluconeogenic enzyme in the liver, were reduced approximately 40 and 50%, respectively, by infection with reticuloendotheliosis-associated virus and reticuloendotheliosis virus. RE virus infection, however, did not affect the hepatic pyruvate carboxylase activity, indicating that inhibition of phosphoenolpyruvate carboxykinase is not due to a general inhibition of all liver enzymes. Birds given injections of UV-inactivated RE viruses or reticuloendotheliosis virus-transformed, non-virus-producing tumor cells also exhibited a reduction in phosphoenolpyruvate carboxykinase activity.
Dendrimer Monolayers as Negative and Positive Tone Resists for Scanning Probe Lithography (2004)

A new scanning probe lithography scheme based on a self-assembled dendrimer monolayer on thin Ti films is presented. The method relies on the versatility of the functionalized dendrimer molecules to effectively function as etch resists by forming a densely packed self-assembled protective monolayer on a Ti film. Patterning of the Ti surface is accomplished using an AFM tip either as an ultra sharp scribe or as an electrical field point source to modify the monolayer. This, coupled to carefully selected etching conditions, allows the use of the dendrimer monolayers as both negative and positive tone resists. Facile formation of TiO2 features ca. 25 nm wide and 12 nm tall on silicon oxide and ca. 50 nm wide gaps in a thin Ti film can easily be achieved. The dendrimer resist approach can be further developed in order to improve the minimum feature size to the single dendrimer molecule level.
Learning to Better Segment Objects from Unseen Classes with Unlabeled Videos (2022)

International audience
Thermal Vapor Ablation for Lung Lesions in a Porcine Model (2015)

Vapor ablation is a potentially safe and efficient means of ablating a targeted region of the lung. We hypothesize that vapor may be useful in treating lesions of the lung in humans.
Face Recognition Using 3-D Models: Pose and Illumination (2006)

Unconstrained illumination and pose variation lead to significant variation in the photographs of faces and constitute a major hurdle preventing the widespread use of face recognition systems. The challenge is to generalize from a limited number of images of an individual to a broad range of conditions. Recently, advances in modeling the effects of illumination and pose have been accomplished using three-dimensional (3-D) shape information coupled with reflectance models. Notable developments in understanding the effects of illumination include the nonexistence of illumination invariants, a characterization of the set of images of objects in fixed pose under variable illumination (the illumination cone), and the introduction of spherical harmonics and low-dimensional linear subspaces for modeling illumination. To generalize to novel conditions, either multiple images must be available to reconstruct 3-D shape or, if only a single image is accessible, prior information about the 3-D shape and appearance of faces in general must be used. The 3-D Morphable Model was introduced as a generative model to predict the appearances of an individual while using a statistical prior on shape and texture allowing its parameters to be estimated from single image. Based on these new understandings, face recognition algorithms have been developed to address the joint challenges of pose and lighting. In this paper, we review these developments and provide a brief survey of the resulting face recognition algorithms and their performance
Data from The Highly Recurrent PP2A Aα-Subunit Mutation P179R Alters Protein Structure and Impairs PP2A Enzyme Function to Promote Endometrial Tumorigenesis (2023)

&lt;div&gt;Abstract&lt;p&gt;Somatic mutation of the protein phosphatase 2A (PP2A) Aα-subunit gene &lt;i&gt;PPP2R1A&lt;/i&gt; is highly prevalent in high-grade endometrial carcinoma. The structural, molecular, and biological basis by which the most recurrent endometrial carcinoma–specific mutation site P179 facilitates features of endometrial carcinoma malignancy has yet to be fully determined. Here, we used a series of structural, biochemical, and biological approaches to investigate the impact of the P179R missense mutation on PP2A function. Enhanced sampling molecular dynamics simulations showed that arginine-to-proline substitution at the P179 residue changes the protein's stable conformation profile. A crystal structure of the tumor-derived PP2A mutant revealed marked changes in A-subunit conformation. Binding to the PP2A catalytic subunit was significantly impaired, disrupting holoenzyme formation and enzymatic activity. Cancer cells were dependent on PP2A disruption for sustained tumorigenic potential, and restoration of wild-type Aα in a patient-derived P179R-mutant cell line restored enzyme function and significantly attenuated tumorigenesis and metastasis &lt;i&gt;in vivo&lt;/i&gt;. Furthermore, small molecule–mediated therapeutic reactivation of PP2A significantly inhibited tumorigenicity &lt;i&gt;in vivo&lt;/i&gt;. These outcomes implicate PP2A functional inactivation as a critical component of high-grade endometrial carcinoma disease pathogenesis. Moreover, they highlight PP2A reactivation as a potential therapeutic strategy for patients who harbor P179R &lt;i&gt;PPP2R1A&lt;/i&gt; mutations.&lt;/p&gt;Significance:&lt;p&gt;This study characterizes a highly recurrent, disease-specific PP2A &lt;i&gt;PPP2R1A&lt;/i&gt; mutation as a driver of endometrial carcinoma and a target for novel therapeutic development.&lt;/p&gt;&lt;p&gt;&lt;i&gt;See related commentary by Haines and Huang, p. 4009&lt;/i&gt;&lt;/p&gt;&lt;/div&gt;