gebhart/patrepeval huggingface dataset:
Graphene based active and passive component development on transparent substrates (2014)

Antennas collect radio waves and channel them into radio frequency (RF) transmission lines which direct the signals to circuits from which information can be demodulated and decoded. Glass, the most common portal between outside and inside environments, is clear at the visible part of the electromagnetic spectrum, and it is also relatively transparent to a large portion of the electromagnetic spectrum useful for radio wave communications. Since glass as a building material is used everywhere, it could be a readily accessible substrate upon which to mount or fabricate the antennas and RF electronics, but only if these circuit components are also transparent. In this paper, we present our development to date of glass RF circuits along two tracks: 1) transparent antennas and 2) graphene based active and passive circuit elements. Along the first track we have demonstrated antennas made from nanowire films capable of an optical transparency of 72% and sheet resistance of 4-5Ω/sq. Along the second track, we have in so far demonstrated graphene on glass field effect transistors with an fmax of 7 GHz, varactors with 1.4:1 tuning range, resistors with 3-70 kΩ, and capacitors from 13-860 pF. This is just the start; our plans are to increase the frequency and tuning ranges of the active and passive devices. Since graphene is inherently transparent at visible wavelengths, we ultimately would like to merge these two tracks to integrate active and passive RF circuitry with the antenna either directly on glass or as an applique put on glass, circuits which we’ve termed RF Glass®.
Cooperative Catalysis by General Acid and Base Bifunctionalized Mesoporous Silica Nanospheres (2005)

A team effort: Mesoporous silica nanosphere (MSN) materials bifunctionalized with a general acid group and a base group in various relative concentrations are described and shown to function as cooperative catalytic systems. The turnover numbers observed indicate that the acid groups can activate substrates in cooperation with the base groups to catalyze reactions that involve carbonyl activation (see picture).
Sensing with porous silicon double layers: A general approach for background suppression (2007)

Abstract One‐dimensional porous silicon photonic crystals can be considered as optical double layers. The reflectivity spectrum of the structure displays a strong peak corresponding to the stop band of the photonic crystal (rugate filter) and Etalon fringes due to Fabry‐Pérot interference in the porous silicon film. The intensity (reflectivity) of the rugate peak and of the peak in the Fourier transform of the Fabry‐Pérot interference spectrum changes differently upon adsorption or binding of biomolecules to the solution/porous silicon interface. Whereas the intensity of the rugate peak only tracks lamp fluctuations, bubbles, and other sources of experimental errors, the intensity of the peak in the FFT spectrum detects in addition adsorption/binding of biomolecules to the surface of the biosensor. The intensity ratio between the rugate peak (reference channel) and the peak in the FFT spectrum (sensing channel) efficiently suppresses background and improves the signal to noise ratio for the detection of biomolecules. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
671. Development of a Successful Lyophilization Process for Lentiviral Vector Clinical Batches (2015)

Since lentiviral vectors are incrinsingly used in various applications (vaccination, gene therapy, T-cell therapies …) and given that so far the best way to keep these vectors is a -80°C storage, more adapted ways of formulation and storage must be developped. Previous attempts have been made to freeze-dry viral vectors: adenovectors and Moloney Monkey Leukemia Virus-based vectors (Cruz et al., 2006) and lentiviral vectors (Shin et al, 2010). None of these attempts have proved satisfactory as the final lyophilized products were not suitable for pharmaceutical applications (mainly due to unacceptable levels of contaminants observed in the final products). We developped an new method to freeze-dry our clinical grade batches of lentiviral vectors. This method allows us to store the batches at -20°C and +4°C while maintaining the characteristics of the particules after reconstitution and the ability to use them as intended (direct injection, T-cell modification …). Our method allows the lyophilization of lentiviral vectors either produced in adherent cells cultures (with FBS) or in suspension cells cultures (without FBS and with synthetic culture medium). The vectors are protected during the freeze-drying process by the addition of a lyoprotectant (sucrose or threalose) and stability is evaluated over time. Quality controls have been performed to evaluate the impurity profiles of the lentivector batches before the freeze-drying process and after the reconstitution of the particules (titer, total proteins, total DNA, HEK 293T proteins), and we demonstrated that the profiles were not impacted by the process and that the batches were still fitting the international pharmacopea recomandations.. We also made some immunogenicity evaluation of our vaccine candidates before and after the lyophilization process, and we were able to show that the process had no impact on the breadth and intensity of the cellular immune response we are able to elicit after a direct injection of the reconstituted particles in mice. THERAVECTYS is a Paris-based, privately-owned, fully integrated discovery & clinical development biotech company. THERAVECTYS develops lentiviral vectors used for human vaccination and immunotherapy applications (CAR-T cells and TCR). An in house cGMP facility is now up and running, allowing us to produce and charaterize our own lentiviral vector clinical batches. A qualified freeze-dryer has been installed in the plant, to systematically encompass this formulation and repartition step in our bioproduction processes.
A self-calibration concept for establishing the complex measurement ability of homodyne network analyzers (1990)

A homodyne phase-shifter-controlled double reflectometer is presented. Its ability to make complex measurements of a network depends on a knowledge of the phase-shifter characteristics. This knowledge is established using fully unknown standards merely by exploiting reciprocity. If a system error correction is performed, the data needed for error correction contain enough information to determine the behavior of the phase shifter, and no additional standards are needed. It is shown by simulation that the measurement of the parameters of the device under test is only weakly influenced by errors in the phase-shifter behavior.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Synthesis, Stereochemical Analysis, and Derivatization of Myricanol Provide New Probes That Promote Autophagic Tau Clearance (2015)

We previously discovered that one specific scalemic preparation of myricanol (1), a constituent of Myrica cerifera (bayberry/southern wax myrtle) root bark, could lower the levels of the microtubule-associated protein tau (MAPT). The significance is that tau accumulates in a number of neurodegenerative diseases, the most common being Alzheimer's disease (AD). Herein, a new synthetic route to prepare myricanol using a suitable boronic acid pinacol ester intermediate is reported. An X-ray crystal structure of the isolated myricanol (1) was obtained and showed a co-crystal consisting of (+)-aR,11S-myricanol (2) and (-)-aS,11R-myricanol (3) coformers. Surprisingly, 3, obtained from chiral separation from 1, reduced tau levels in both cultured cells and ex vivo brain slices from a mouse model of tauopathy at reasonable mid-to-low micromolar potency, whereas 2 did not. SILAC proteomics and cell assays revealed that 3 promoted tau degradation through an autophagic mechanism, which was in contrast to that of other tau-lowering compounds previously identified by our group. During the course of structure-activity relationship (SAR) development, we prepared compound 13 by acid-catalyzed dehydration of 1. 13 had undergone an unexpected structural rearrangement through the isomyricanol substitution pattern (e.g., 16), as verified by X-ray structural analysis. Compound 13 displayed robust tau-lowering activity, and, importantly, its enantiomers reduced tau levels similarly. Therefore, the semisynthetic analogue 13 provides a foundation for further development as a tau-lowering agent without its SAR being based on chirality.
Ranking anomalies in data centers (2012)

Data centers are growing in size and complexity driven by trends such as cloud computing and on-line services. Such large data centers pose several challenges for system management. Key among them is anomaly detection which is required to monitor and analyze metrics across several thousands servers and across multiple layers of abstractions to detect anomalous system behavior. In practice, multiple anomaly detection tools are used to continuously raise alarms across multiple metrics and servers. These alarms include both true positives and false alarms. Administrators and management tools act on these alarms for diagnosis and deeper root cause analysis and take appropriate management actions to mitigate the anomalous behaviors. Given the scale and scope of the system, the administrators and management tools are overwhelmed with the large number of alarms at any given instant, many of which are false alarms. It is therefore necessary to prioritize and rank these alarms, so as to take timely actions that maintain the service level agreements for the data center. Existing techniques for such ranking are ad-hoc and not scalable. We propose ranking windows of monitored metrics based on their probability of occurrence. We explain how these probabilities can be computed based either on the false positive rates for which the accompanying anomaly detectors were designed, or, when available, on the probability models underlying the false positive rates. In the simplest case, the ranking procedure reduces to computing the Z-score of the observed measurements and computing a statistic from a window of Z-scores to use as a basis for ranking. The proposed techniques are reliable, lightweight and easy to deploy in the modern data center. We have validated these techniques on synthetic data containing injected anomalies and on data acquired from production data centers.
Visual Feedback Based Droplet Size Regulation in Electrohydrodynamic Jet Printing (2014)

Electrohydrodynamic jet (e-jet) printing is a recent micro-manufacturing technique that uses electrostatic force to draw out ink from a conductive nozzle onto a conductive substrate. While the advantages (high speed and resolution, flexibility) of e-jet printing over ink jet printing and other microfabrication methods are abundant, precise control of the process is necessary for successful commercialization of the technology. This paper shows how visual feedback through image processing may be used to regulate the volume of printed droplets for increased manufacturing precision.
A Micro-Opto-Mechanical Photoacoustic Spectrometer (2008)

This report describes progress achieved in a one-year LDRD feasibility study of a Photo Acoustic Spectrometer (PAS). Specifically, this team sought to create an all-optical and very small PhotoAcoustic Spectrometer Sensing system (PASS system). The PASS system includes all the hardware needed within a gas environment to analyze the presence of a large variety of molecules. The all-optical PASS system requires only two optical-fibers to communicate with the opto-electronic power and readout systems that exist outside of the gas environment. These systems can be at any distance from the PASS system as signal loss through the optical fibers is very small. The PASS system is intended to be placed in a small space where gases need to be measured and thus must be very small. The size and all-optical constraints placed on the PASS system demand a new design. The PASS system design includes a novel acoustic chamber, optical sensor, power fiber coupling and sensing fiber coupling. Our collaborators at the Atomic Weapons Establishment (AWE) have proven the capabilities of a complete photoacoustic spectrometer that uses a macro-scale PASS system (first 2 references). It was our goal to miniaturize the PASS system and turn it into an all-optical system to allow for its use in confined spaces that prohibit electrical devices. This goal demanded the study of all the system components, selection of an appropriate optical readout system and the design and integration of the optical sensor to the PASS system. A stretch goal was to fabricate a completed PASS system prototype.
Discharge efficiency in plasma displays (2000)

The dependence of the panel efficacy of an alternating current-surface-discharge plasma display on the input power is investigated. Test panels with a design resembling the one used in main stream commercial products are used. The input power is varied in two ways: namely by changing the dielectric layer capacitance (thickness) and by changing the sustain voltage. An interesting different behavior is found: for increasing capacitance the efficacy decreases markedly, whereas for increasing sustain voltage the efficacy increases slightly. The different behavior is attributed to changes in the ion heating losses. It is found that plasma saturation, which implies a fundamental trade-off between luminance and efficacy, is not significant at practical input power values. A high luminance and a high efficacy are concurrent for a plasma panel design with a low dielectric layer capacitance and a high sustain voltage.
Integrated Interventional Devices For Real Time 3D Ultrasound Imaging and Therapy (2006)

Two recent advances have expanded the potential of medical ultrasound: the introduction of real‐time 3‐D ultrasound imaging with catheter, transesophageal and laparoscopic probes and the development of interventional ultrasound therapeutic systems for focused ultrasound surgery, ablation and ultrasound enhanced drug delivery. This work describes devices combining both technologies. A series of transducer probes have been designed, fabricated and tested including: 1) a 12 French side scanning catheter incorporating a 64 element matrix array for imaging at 5MHz and a piston ablation transducer operating at 10 MHz. 2) a 14 Fr forward‐scanning catheter integrating a 112 element 2‐D array for imaging at 5 MHz encircled by an ablation annulus operating at 10 MHz. Finite element modeling was then used to simulate catheter annular and linear phased array transducers for ablation. 3) Linear phased array transducers were built to confirm the finite element analysis at 4 and 8 MHz including a mechanically focused 86 element 9 MHz array which transmits an ISPTA of 29.3 W/cm2 and creates a lesion in 2 minutes. 4) 2‐D arrays of 504 channels operating at 5 MHz have been developed for transesophageal and laparascopic 3D imaging as well as therapeutic heating. All the devices image the heart anatomy including atria, valves, septa and en face views of the pulmonary veins.
New developments in laser-assisted magnetic recording (2000)

Recent progress in laser-assisted magnetic recording, which combines optical and magnetic recording technologies, is described in this paper. This study confirms that laser-assisted magnetic recording is a good candidate for high areal density magnetic recording. Improved disk performance was demonstrated in the area of frequency response, media noise, and thermal decay. The improvements in media design include the change in temperature dependence of the recording layer, an increased perpendicular anisotropy, and a thermally efficient layer structure. These improved media properties result in a high linear density and good thermal stability.
<i>In vivo</i> measurement of lithium in the body by a neutron activation analysis technique (1986)

A technique has been developed for in vivo determination of lithium content in the head (and potentially in the whole body and in selected organs) of patients undergoing lithium therapy. It is based on the measurement of tritium induced by the 6Li(n,alpha)T nuclear reaction after neutron irradiation of the body. The fraction of tritium exhaled in the expired air in the form of HT is collected, separated from the other gases, and counted in a high-sensitivity beta counter. The feasibility of the technique was demonstrated by measurements of lithium in the head of a sheep and in the whole body of rats, following the administration of 6LiCl (enriched 6Li isotope, 95.46% abundancy). The precision of the technique is acceptable for clinical applications based on a maximum propagated error of 8.4%. The sensitivity is 1 count/d (from T activity) per 10 mSv (total dose) and 1 microgram of 6Li. This indicates that studies on patients under 6Li treatment can be performed successfully with a radiation dose to the head of 1-2 mSv.
Novel and potent gastrin and brain cholecystokinin antagonists from Streptomyces olivaceus. Taxonomy, fermentation, isolation, chemical conversions, and physico-chemical and biochemical properties. (1991)

The discovery and physico-chemical characterization of three novel and minor virginiamycin M1 analogs as potent gastrin antagonists from a culture of a strain of Streptomyces olivaceus are described. These analogs are L-156,586, L-156,587 and L-156,588. They are, respectively, 15-dihydro-13,14-anhydro-, 13,14-anhydro- and 13-desoxy-analogs of virginiamycin M1. We also chemically converted virginiamycin M1 (via L-156,587) to L-156,586 and its unnatural epimer, L-156,906. These analogs are competitive and selective antagonists of gastrin and brain cholecystokinin binding at nanomolar concentrations. These are the most potent gastrin/brain cholecystokinin antagonists from natural products. The same compounds showed poor Gram-positive antibiotic activity versus virginiamycin M1. Structurally related Gram-positive antibiotics, griseoviridin and madumycin I, were inactive in gastrin and brain cholecystokinin binding at up to 100 microM.
A Family of Acetylcholine-gated Chloride Channel Subunits in Caenorhabditis elegans (2004)

The genome of the nematode Caenorhabditis elegans encodes a surprisingly large and diverse superfamily of genes encoding Cys loop ligand-gated ion channels. Here we report the first cloning, expression, and pharmacological characterization of members of a family of anion-selective acetylcholine receptor subunits. Two subunits, ACC-1 and ACC-2, form homomeric channels for which acetylcholine and arecoline, but not nicotine, are efficient agonists. These channels are blocked by d-tubocurarine but not by alpha-bungarotoxin. We provide evidence that two additional subunits, ACC-3 and ACC-4, interact with ACC-1 and ACC-2. The acetylcholine-binding domain of these channels appears to have diverged substantially from the acetylcholine-binding domain of nicotinic receptors.
Acoustic isolation vessel for measurement of the background noise in microphones (1993)

An acoustic isolation vessel has been developed to measure the background noise in microphones. The test microphone is installed in an inner vessel, which is suspended within an outer vessel, and the intervening air space is evacuated to a high vacuum. An analytical expression for the transmission coefficient is derived, based on a five-media model, and compared to experiment. At an isolation vacuum of 5×10−6 Torr the experimental transmission coefficient was found to be lower than −155 dB at frequencies ranging from 40 to 1200 Hz. Measurements of the A-weighted noise levels of commercial condenser microphones of four different sizes show good agreement with published values.
A MEMS Differential-Scanning-Calorimetric Sensor for Thermodynamic Characterization of Biomolecules (2012)

This paper presents a microelectromechanical systems sensor for differential scanning calorimetry (DSC) of liquid-phase biomolecular samples. The device consists of two microchambers, each of which is based on a freestanding polyimide diaphragm and surrounded by air cavities for thermal isolation. The chambers are each equipped with a thin-film gold resistive heater and temperature sensor and are also integrated with a thin-film antimony-bismuth (Sb-Bi) thermopile. For DSC measurements, the chambers are respectively filled with a biomolecular sample and a reference solution, with their temperatures varied at a constant rate. The thermopile voltage is measured to determine the differential power between the chambers for thermodynamic characterization of the biomolecules. The device is used to measure the unfolding of proteins in a small volume (1 μL) and at practically relevant concentrations (approximately 1 mg/mL). Thermodynamic properties, including the enthalpy change and melting temperature, during this conformational transition are determined and found to agree with published data.
The multifocus plenoptic camera (2011)

The focused plenoptic camera is based on the Lippmann sensor: an array of microlenses focused on the pixels of a conventional image sensor. This device samples the radiance, or plenoptic function, as an array of cameras with large depth of field, focused at a certain plane in front of the microlenses. For the purpose of digital refocusing (which is one of the important applications) the depth of field needs to be large, but there are fundamental optical limitations to this. The solution of the above problem is to use and array of interleaved microlenses of different focal lengths, focused at two or more different planes. In this way a focused image can be constructed at any depth of focus, and a really wide range of digital refocusing can be achieved. This paper presents our theory and results of implementing such camera. Real world images are demonstrating the extended capabilities, and limitations are discussed.
Influence of pore structure on the properties of green concrete derived from natural pozzolan and nanosilica (2020)

The strength, pore structure, morphology and mineralogical composition of hydration products of natural pozzolan (NP) and nanosilica (nSiO2) based alkali activated binder (AAB) were examined. It was noted that AAB without nSiO2 was relatively porous with the presence of micro-, meso- and macro-level pores. In contrast, as the proportion of nSiO2 increased in the mixture, the pore structure started to refine with a reduction in the pore volume due to transformation of source material to polymeric compound, such as C-A-S-H with a higher Al absorption in the binder structure. The incorporation of 5% and 7.5% nSiO2 resulted in the refinement of the pore structure due to enhanced polycondensation. Consequently, there was considerable improvement in the mechanical properties. The experimental data indicated that the pore structure evaluation through NMR has served as a tool to understand the relation between the micro- and macro-level performance of the developed AAC.
Computer-Aided Detection of Diffuse Liver Disease in Ultrasound Images (1992)

The authors are developing an automated method of determining measures of texture in liver ultrasound images to improve the accuracy of diagnosis of diffuse liver abnormalities. In each digitized image, the background trend of pixel values is estimated to isolate the underlying pattern of liver texture. After correcting for background trend, the root mean square (RMS) variation and the first moment of the power spectrum are calculated; these measures have been applied successfully to texture analysis of digital chest radiographs. Background trend-corrected measurements detected statistically significant differences in digitized ultrasound images of 11 normal and 11 abnormal livers. Without correction for background trend, the measures are unable to distinguish normal from abnormal liver texture. The authors also investigated the effect on the texture measures of varying several ultrasound imaging parameters in normal patients and in an ultrasound phantom.