gebhart/patrepeval huggingface dataset:
Force-Detected NMR in a Homogeneous Field: Experiment Design, Apparatus, and Observations (2002)

Here I present motivation, experimental progress, and theoretical aspects of the BOOMERANG (better observation of magnetization enhanced resolution and no gradient) method of force-detected NMR, a general approach to extending arbitrary NMR experiments to the micron scale and below. Enabling quality of BOOMERANG is that its sensitivity scales much more favorably than traditional inductive detection for small samples. A reduction in the sample size accessible by NMR is strongly motivated by such goals as massively parallel analysis in support of combinatorial chemistry, portability in support of planetary exploration, and the general advantage of highest sensitivity per unit cost. The key design insight is that the spin-dependent forces are independent of the field homogeneity across the sample. However, throughput is optimized only by providing field homogeneity during detection sufficient to allow coherent control over all target spins in a sample. I present our BOOMERANG design concepts and strategies, which allow detectors with high geometrical efficiency and good prospects for low mechanical dissipation. The design principles are quantitatively confirmed using a prototype mm-scale spectrometer. Our experimental results, which include proton and fluorine FT-NMR
spectra in solids and liquids, heteronuclear J spectra, and liquid-state spin echoes with sub-Hz linewidths, emphasize BOOMERANG’s general spectroscopic applicability. Fabrication of a high-sensitivity spectrometer optimized for 60-micron samples is underway in conjunction with the Microdevices Laboratory (MDL) at the NASA Jet Propulsion Laboratory (JPL). Using state-of-the-art lithography and electrodeposition techniques, we have fabricated magnets and mechanical oscillator structures that show promise for incorporation into spectrometers for in-situ planetary exploration, and for massively parallel analysis. As the sample size decreases, sensitivity is dominated by quantum-statistical noise in the sample, or spin noise. This fundamental problem is mitigated by the CONQUEST measurement paradigm involving multiple time-correlated measurements on a spin system of interest. This is an essential ingredient in converting polarization
fluctuations to coherent time-domain spectroscopy or to images with arbitrary numbers of spins in each pixel.
Video Streaming Security: Window-Based Hash Chain Signature Combines with Redundancy Code - YouTube Scenario as an Internet Case Study (2010)

This paper provides a performance study for securing media streaming based on hash chain methodology. We introduce a new technique that combines the signature of window-based hash chain with redundancy codes for achieving high reliability and robustness against many attacks. Also, the Window technique integrates the Time-Stamped which strongly eliminates the anti-replay attack. It will also control the management of many users accessing the same video in different instant times. The Window-Based algorithm with redundancy code will be compared against Packet-Based or just Block-Based video streaming security. The analytical and simulation results indicate that, the Window-Based Hash Chain Signature combine with Redundancy Code (WB & RC) is a good solution for video streaming security in terms of reliability and robustness. The times of signature creation and verification are accepted under the standard delay recommendations of real time applications. Our case study provides You Tube as a successful scenario over Internet. The privacy of You Tube will relay on a secure email in user access which represents an efficient way in mobility issue.
Metal nanofibrils embedded in long free-standing carbon nanotube fibers with a high critical current density (2018)

With the growth of nanoelectronics, the importance of thermal management in device packaging and the improvement of high-current-carrying interconnects/wires for avoiding the premature failure of devices have been emphasized. The heat and electrical transport properties of the bulk may not be valid in the characterization of a material at the nanometer level, because the phenomena that occur at the interfaces and grain boundaries become dominant. The failure mechanism of bulk metal interconnects has been understood in the context of electromigration; however, in nanoscale materials, the effect of the heat dissipation that occurs at the nanointerfaces may play an important role. Here, we report the preparation of continuous carbon nanotube (CNT)–Cu composite fibers that possess Cu nanofibrillar structures with a high current-carrying capacity. Various-shaped CNT–Cu microfibers with different Cu grain morphologies were produced via Cu electroplating on continuous CNT fibers. Cu fibril structures were embedded in the voids inside the CNT fiber during the early stage of electrodeposition. The temperature-dependent and magnetic field-dependent electrical properties and the ampacity of the produced CNT–Cu microfibers were measured, and the failure mechanism of the fiber was discussed. The interconnection of Cu nanograins on the surface of the individual CNTs contributed to the enhancement in the charge-carrying ability of the fiber. The effective ampacity of the Cu nanofibrils was estimated to be ~1 × 107 A/cm2, which is approximately 50 times larger than the ampacity measured for a bulk Cu microwire. Nanoscale metal fibrils increase the maximum current a spun carbon nanotube fiber can carry before failing, researchers in South Korea demonstrate. Ensuring that components don’t overheat is a crucial consideration when designing electronic devices. High electrical currents can heat and thus damage the wires, or interconnects, that link different parts of the circuit. This is particularly important in nanoelectronics, where the interconnects are narrow. Sang Hyun Lee from the Korea Institute of Science and Technology, Jeonbuk, and colleagues addressed this problem by embedding copper fibrils within continuous carbon nanotube fiber. They compared various fibril shapes to systematically study the electrical and thermal properties at the interface between the copper and the carbon nanotube. The maximum current their composite fibers could tolerate before damage occurred was fifty times higher than for conventional copper microwires. The copper nanofibrils are formed at the void inside the long continuous carbon nanotube (CNT) fiber by electroplating. Electrical conduction through the composite fiber was dominated by the nanofibrils even though their cross-sectional area is much smaller than that of CNTs. The nanofibrils could carry a very high current density due to their bamboo-like structure and the thermal dissipation through CNTs.
Risk levels for mite allergens. Are they meaningful? (1998)

Allergens found in house dust are among the most common environmental antigens to which man is naturally exposed. Standardized methods for measuring allergen exposure are essential for assessing the relationship between exposure, sensitization, and the severity of asthma. Monoclonal antibody-based assays are the most widely used method for assessing allergen exposure. In the effort to define the best “index of exposure” to mite allergens, several factors need to be investigated, including: 1) whether allergen should be measured in reservoir dust or airborne 2) whether the results of reservoir measurement should be expressed as recovered allergen per unit weight or per unit area. As yet, airborne sampling is insufficiently sensitive to produce reliable and repeatable results. Therefore, measurement of house-dust-mite allergen concentration in reservoir dust should be regarded as the best-validated index of exposure. The results should be expressed and reported both per unit weight (concentration) and per unit area. The strongest predictor of chronic symptoms and acute exacerbation of asthma is sensitization to indoor allergens. A simple dose-response relationship between IgE-mediated hypersensitivity and allergen exposure has been established. For example, exposure to more than 2 μg Group 1 mite allergen/g dust should be regarded as a risk factor for the development of IgE antibody and asthma in susceptible children. The quantitative relationship between exposure and symptoms in patients already sensitized is complex due to a number of possible confounding factors (e.g., other allergens, viruses, asthma medication). A simple threshold level for provocation of asthmatic symptoms has not been clearly defined.
Hydrothermal synthesis of copper molybdates (1986)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHydrothermal synthesis of copper molybdatesAhmad Moini, Roberta Peascoe, Philip R. Rudolf, and Abraham ClearfieldCite this: Inorg. Chem. 1986, 25, 21, 3782–3785Publication Date (Print):October 1, 1986Publication History Published online1 May 2002Published inissue 1 October 1986https://pubs.acs.org/doi/10.1021/ic00241a016https://doi.org/10.1021/ic00241a016research-articleACS PublicationsRequest reuse permissionsArticle Views543Altmetric-Citations31LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-AlertscloseSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts
Purification and characterization of a protease from Bacteroides gingivalis 381 (1987)

An intracellular membrane-free, trypsinlike protease was isolated from cells of Bacteroides gingivalis 381. The protease was extracted from the cells by ultrasonic treatment and was purified about 250-fold with a recovery of 2% by sequential procedures. The properties of the protease were as follows: its optimal pH was 8.5; its activity was almost completely lost on incubation at 50 degrees C for 15 min; its activity was inhibited by diisopropylfluorophosphate, p-toluenesulfonyl-L-lysine chloromethyl ketone hydrochloride, leupeptin, Mn2+, Cu2+, and Zn2+; it hydrolyzed casein, azocasein, N-alpha-benzoyl-DL-arginine-p-nitroanilide (BAPNA), bovine serum albumin, azocoll, and gelatin, but not N-alpha-benzoyl-DL-lysine-p-nitroanilide or human serum immunoglobulin A; its molecular weight was estimated as 45,000 by gel filtration and 50,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis; and its Km values for azocasein and BAPNA were 1.11% and 0.19 mM, respectively.
Novel Bifunctional Thiolcarboxylic Acid Esters Useful as Crosslinking Agents for Optical Materials (2000)

Abstract Novel bifunctional thiolcarboxylic acid esters such as thiodimethacrylates have been prepared in good yield by reaction of dimercaptanes with acid chloride in KOHaq and organic solvent system in the presence of phase transfer catalyst under mild reaction conditions. These bifunctional thiomethacrylates are useful as crosslinking agents having high refractive indices.
Epigenetic Down-Regulation and Suppressive Role of <i>DCBLD2</i> in Gastric Cancer Cell Proliferation and Invasion (2008)

The promoter region of Discoidin, CUB and LCCL domain containing 2 (DCBLD2) was found to be aberrantly methylated in gastric cancer cell lines and in primary gastric cancers, as determined by restriction landmark genomic scanning. DCBLD2 expression was inversely correlated with DCBLD2 methylation in gastric cancer cell lines. Treatment with 5-aza-2'-deoxycytidine and trichostatin A partially reversed DCBLD2 methylation and restored gene expression in DCBLD2-silenced cell lines. In an independent series of 82 paired gastric cancers and adjacent normal tissues, DCBLD2 expression was down-regulated in 79% of gastric cancers as compared with normal tissues as measured by real-time reverse transcription-PCR. Pyrosequencing analysis of the DCBLD2 promoter region revealed abnormal hypermethylation in gastric cancers, and this hypermethylation was significantly correlated with down-regulation of DCBLD2 expression. Furthermore, ectopic expression of DCBLD2 in gastric cancer cell lines inhibited colony formation in both anchorage-dependent and anchorage-independent cultures and also inhibited invasion through the collagen matrix. These data suggest that down-regulation of DCBLD2, often associated with promoter hypermethylation, is a frequent event that may be related to the development of gastric cancer.
Enhanced thermoelectric figure of merit in thin GaAs nanowires (2015)

Combining density functional theory and the nonequilibrium Green's function method, we investigate the thermoelectric properties of thin GaAs nanowires (NWs). After identifying the most stable structures for GaAs NWs, either in wurtzite (wz) or zinc blende (zb) stacking, we present a systematic analysis on the thermoelectric properties of these NWs and their dependence on stacking type (wz or zb), size of NWs, and temperature. Although bulk GaAs is a well-known poor thermoelectric material, the thermoelectric figure of merit, ZT, is significantly enhanced in thin GaAs NWs. Typically, the room temperature ZT of a 1.1 nm-diameter GaAs NW reaches as high as 1.34, exhibiting more than 100-fold improvement over the bulk counterpart, which is attributed to both the reduced thermal conduction and enhanced power factor in thin NWs. Adopting their unique electronic characteristics, further enhancement is possible through surface engineering, for example, the introduction of surface roughness or dopants.
Real-time scattering compensation for time-of-flight camera (2019)

3D images from time-of-flight cameras may suffer from false depth readings caused by light scattering. In order to reduce such scattering artifacts, a scattering compensation procedure is proposed. First, scattering is analysed and expressed as a linear transform of a complex image. Then, a simple scattering model is formulated. Assuming a space invariant point spread function as a model for the scattering leads to a solution in a form of a deconvolution scheme whose computational feasibility and practical applicability are further discussed in this paper.
Optical absorption enhancement in silicon nanowire and nanohole arrays for photovoltaic applications (2010)

In this proceeding, we simulate the optical properties of vertically-aligned silicon nanowire and nanohole arrays using the transfer matrix method. We find that the optical absorption in both silicon nanowire and nanohole arrays improves with increasing lattice constant up to 600nm - 700nm. We attribute the observed optical absorption enhancement effect to an increase in the field concentration inside the active silicon region and the excitation of guided resonance modes. For optimized parameters, both structures can be more absorptive than an equally-thick silicon solid film with an optimal single layer Si<sub>3</sub>N<sub>4</sub> anti-reflection coating. This conclusion holds true for both optically thin (2.33μm) and optically thick (100μm) structures. For optically thin structures, the enhancement in the optimal nanohole array exceeds the conventional light trapping limit. For optically thick structures, the enhancement in both optimal nanohole and nanowire arrays exceeds the light trapping limit. Additionally, we show that the overall absorption efficiencies for hexagonal and square lattices of nanowires are very similar.
Avionics systems design for cooperative unmanned air and ground vehicles (2004)

Thesis (S.M. and E.A.A.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2004.
Growth of Cu films on hydrogen terminated Si(100) and Si(111) surfaces (1994)

We have employed reflection high energy electron diffraction (RHEED) and high resolution transmission electron microscopy (HREM) to study Cu films grown on hydrogen terminated Si(100) and Si(111) substrates by molecular beam epitaxy. X-ray diffraction and RHEED studies indicate 〈100〉Cu growth on Si(100) and 〈111〉Cu growth on Si(111). HREM reveals orientation relationships of [001]Cu∥[011]Si, (010)Cu∥(011)Si and [1̄12]Cu∥[011]Si, (220)Cu∥(111̄)Si for Si(100) and Si(111), respectively. A copper silicide layer forms on Si(100) with deposition and appears to aid in proper lattice matching. No significant interdiffused region was detected in the films deposited on Si(111), however, distinct orientational variants were observed in this case.
Intravital videomicroscopy of peritubular capillaries in renal ischemia (2002)

The recent refinement and computerization of intravital microscopy have permitted us to monitor microcirculation in vivo with minimal invasion. Here, we report on the first findings made with the use of a pencil-lens intravital microscope as applied to the ischemic rat kidney. Peritubular capillary and glomerular blood flow were monitored under basal conditions, during renal artery occlusion, and immediately after release of the clamp. Erythrocyte velocity was calculated as an angle in consecutive spatiotemporal images. Intravital videomicroscopy during the reperfusion period showed intermittent cessation and partial recovery of blood flow in both peritubular and glomerular capillaries. Blood flow was uniformly orthograde under control conditions; however, the retrograde flow occurred on reperfusion. The patency of peritubular capillaries was partially compromised during the early reperfusion period but rapidly recovered. The recovery of glomerular microcirculation occurred faster than that of peritubular capillaries. We suggest that a functional vasculopathy develops very early in the course of ischemia-reperfusion in superficial cortical microvasculature and is more pronounced in peritubular capillaries, thus accounting for the development of patchy injury of tubular epithelia.
Stress and piezoelectric properties of aluminum nitride thin films deposited onto metal electrodes by pulsed direct current reactive sputtering (2001)

Polycrystalline aluminum nitride thin films were deposited onto platinum, aluminum, and titanium electrodes by reactive magnetron sputtering in the pulsed direct current mode. The films exhibited all a columnar microstructure and a c-axis texture. The built-in stress and the piezoelectric properties of these films were studied as a function of both the processing conditions and the electrode material. Stress was found to be very much dependent on the growth conditions, and values ranging from strong compression to high tension were observed. The piezoelectric d33,f coefficient was shown to rely on substrate quality and ionic bombardment: The nucleation surface must be stable with regard to the nitrogen plasma and present a hexagonal symmetry and, on the other hand, enough energy must be delivered to the growing film through ionic bombardment.
Renal Denervation in the Acute Phase of Ischemic Stroke Provides Brain Protection in Hypertensive Rats (2017)

RD posttreatment improved outcome in the hypertensive AIS rat model. Therefore, we suggest that BP normalization by RD may be a promising therapeutic strategy for AIS.
Molecular modeling for the design of a biomimetic chimeric ligand. Application to the purification of bovine heart L-lactate dehydrogenase (1999)

Molecular modeling was employed for the design of a biomimetic chimeric ligand for L-lactate dehydrogenase (LDH). This ligand is an anthraquinone monochlorotriazinyl dye comprising two moieties: (a) the ketocarboxyl biomimetic moiety, 2-(4-aminophenyl)-ethyloxamic acid, linked on the monochlorotriazine ring, mimicking the natural substrate of LDH, and (b) the anthraquinone chromophore moiety, linked also on the same monochlorotriazine ring via a diaminobenzenesulfonate group, acting as pseudomimetic of the cofactor NAD+. The positioning of the dye in the enzyme's binding site is primarily achieved by the recognition and positioning of the pseudomimetic anthraquinone moiety. The positioning of the biomimetic ketocarboxylic moiety is based on a match between the polar and hydrophobic regions of the enzyme's binding site with those of the biomimetic moiety of the ligand. The length of the biomimetic moiety is predetermined for the ketoacid to approach the enzyme catalytic site and form charge–charge interactions. The biomimetic chimeric ligand and the commercial nonbiomimetic ligand Cibacron® blue 3GA (CB3GA), were immobilized on crosslinked beaded agarose gel via their chlorotriazine ring. The two affinity adsorbents were evaluated for their purifying ability for LDH from six sources (bovine heart and pancreas, porcine muscle, chicken liver and muscle, and pea seeds). The biomimetic adsorbent exhibited approximately twofold higher purifying ability for LDH compared to the CB3GA adsorbent; therefore, the former was integrated in the purification procedure of LDH from bovine heart extract. The LDH afforded by this two-step purification procedure shows specific activity equal to 600 U/mg (25°C) and a single band after SDS-PAGE analysis. © 1999 John Wiley & Sons, Inc. Biotechnol Bioeng 63: 322–332, 1999.
Changes in brain testosterone and allopregnanolone biosynthesis elicit aggressive behavior (2005)

In addition to an action on metabolism, anabolic/androgenic steroids also increase sex drive and mental acuity. If abused, such steroids can cause irritability, impulsive aggression, and signs of major depression [Pearson, H. (2004) Nature 431, 500-501], but the mechanisms that produce these symptoms are unknown. The present study investigates behavioral and neurochemical alterations occurring in association with protracted (3-week) administration of testosterone propionate (TP) to socially isolated (SI) and group-housed male and female mice. Male but not female SI mice exhibit aggression that correlates with the down-regulation of brain neurosteroid biosynthesis. However, in female mice, long-term TP administration induces aggression associated with a decrease of brain allopregnanolone (Allo) content and a decrease (approximately 40%) of 5alpha-reductase type I mRNA expression. In spayed mice treated with TP, restitution experiments with progesterone and estrogen normalize brain Allo content and prevent aggression. Submicromolar doses of S-norfluoxetine (S-NFLX) that are insufficient to inhibit serotonin reuptake selectively increase brain Allo content and abolish TP-induced aggression. Our results support the view that TP-induced aggressive behavior is the result of a TP-mediated neurosteroid biosynthesis down-regulation that can be reversed by the S-NFLX-induced increase of brain Allo content.
Experimental demonstration of multicarrier-CDMA for passive optical networks (2008)

Optical multicarrier-CDMA is experimentally demonstrated for the first time. The system supports up to 256 users at a total bit rate of 15-Gb/s with almost no penalty after 70-Km transmission.
Laser-induced damage threshold and laser processing of GaN (2000)

The single-shot pulse laser-induced damaging thresholds (LIDTs), an important laser-optical constant of GaN material, were determined to approximately 34 and 65 nJ upon the irradiation of 400 and 800 nm wavelengths, 150 fs duration laser pulse focused by 40X magnification of dry objective lens (a lateral size of focal spot roughly at 1.22 (lambda) /NA, where NA equals 0.65). The critical energy of sub- threshold pulses was determined for multi-shot optical damaging. The factors that influenced the LIDTs, optical properties of damaged GaN material and the possibility of laser processing of nitride devices were also discussed.