gebhart/patrepeval huggingface dataset:
Surface functionalization of graphene quantum dots with small organic molecules from photoluminescence modulation to bioimaging applications: an experimental and theoretical investigation (2013)

Surface chemistry provides an alternative approach to modulate the emission colour and efficiency of graphene quantum dots. We systematically investigated the surface chemistry of graphene quantum dots functionalized with a series of small organic molecules combining experimental and theoretical approaches. Experimental results indicated that surface functionalization with functional groups such as alcohol, amine and thiol can effectively tune the fluorescence of graphene quantum dots, and proved that amino groups can highly elevate the quantum yields of modified graphene quantum dots. The emission efficiency of 1,2-ethylenediamine functionalized graphene quantum dots reached up to 17.6% due to specific proton transfer to the conjugated fluorophore-like structure from ammonium formed by protonation. The polyaromatic structure within the graphene quantum dots was proposed to explain the fluorescence enhancement mechanism of graphene quantum dots functionalized by diamines. The computational results suggested that not only the size of the polyaromatic structures within graphene quantum dots can change their emissions, but surface functionalization can also tune their photoluminescence through modulating their band gaps. Toxicity experiments indicated that diamine-functionalized graphene quantum dots showed low cell toxicity similar to that of pristine graphene quantum dots. Moreover, the bioimaging experiments suggested that functionalized graphene quantum dots had identical abilities to label cells at a lower concentration than pristine graphene quantum dots owing to their higher quantum yields.
Simultaneous production of detergent stable keratinolytic protease, amylase and biosurfactant by Bacillus subtilis PF1 using agro industrial waste (2016)

The present study is an attempt to optimize simultaneous production of keratinolytic protease, amylase and biosurfactant from feather meal, potato peel and rape seed cake in a single media by response surface methodology to evaluate their biochemical properties for detergent additive. The optimization was carried out using 20 run, 3 factor and 5-level of central composite design on design expert software which resulted in a 1.2, 0.84 and 2.28 fold increase in protease, amylase and biosurfactant production. The proteolytic activity was found to be optimum at pH 9.0 and 60 °C while optimum amylolytic activity was recorded at pH 6.0 and 70 °C respectively. Both enzymes were found to be stable in the presence of organic solvents, ionic and commercial detergent and oxidizing agents. The biosurfactant was extracted with chloroform and was found to be stable at varying pH and temperature; however a reduction in the activity was observed at temperature higher than 70 °C. The isolated enzymes and biosurfactants may find applications in the effective removal of stains.
Native voice, self-concept and the moral case for personalized voice technology (2016)

Purpose (1) To explore the role of native voice and effects of voice loss on self-concept and identity, and survey the state of assistive voice technology; (2) to establish the moral case for developing personalized voice technology. Methods This narrative review examines published literature on the human significance of voice, the impact of voice loss on self-concept and identity, and the strengths and limitations of current voice technology. Based on the impact of voice loss on self and identity, and voice technology limitations, the moral case for personalized voice technology is developed. Results Given the richness of information conveyed by voice, loss of voice constrains expression of the self, but the full impact is poorly understood. Augmentative and alternative communication (AAC) devices facilitate communication but, despite advances in this field, voice output cannot yet express the unique nuances of individual voice. The ethical principles of autonomy, beneficence and equality of opportunity establish the moral responsibility to invest in accessible, cost-effective, personalized voice technology. Conclusions Although further research is needed to elucidate the full effects of voice loss on self-concept, identity and social functioning, current understanding of the profoundly negative impact of voice loss establishes the moral case for developing personalized voice technology. Implications for Rehabilitation Rehabilitation of voice-disordered patients should facilitate self-expression, interpersonal connectedness and social/occupational participation. Proactive questioning about the psychological and social experiences of patients with voice loss is a valuable entry point for rehabilitation planning. Personalized voice technology would enhance sense of self, communicative participation and autonomy and promote shared healthcare decision-making. Further research is needed to identify the best strategies to preserve and strengthen identity and sense of self.
Characterization of tritium breeding ratio and energy multiplication factor of lithium-based ternary alloys in IFE blankets (2015)

Lawrence Livermore National Laboratory (LLNL) developed an inertial fusion energy (IFE) chamber concept that uses liquid lithium as the tritium breeder and primary coolant. Lithium metal has multiple benefits including high tritium breeding capability and excellent heat transfer properties. Nevertheless, lithium highly reacts with air and water to create an alkali metal fire. As a result, LLNL is now conducting research and development to identify lithium-based ternary alloys that will keep the favorable attributes of lithium while reducing the chemical reactivity and fire hazards. 3-D Monte Carlo calculations of a simplified model of the laser IFE reactor were performed for the assessment of two characteristics: tritium breeding ratio (TBR) that is the ratio of tritium produced in the system to tritium consumed, and the fusion energy multiplication factor (EMF) that is the ratio of the total power deposited in the blanket and other regions outside the IFE chamber by neutrons, gammas, and alpha particles to the fusion power. The TBR and EMF were calculated for each ternary combination as a function of the alloy composition varying the atomic percent of each element in the mixture from 0 to 100% by increments of 5%. Mixtures that guarantee a TBR of at least 1.02 and an EMF of at least 1.10 were considered viable. It was found that (1) alloys containing bismuth or lead offer the wider range of acceptable compositions; (2) ternary alloys made of lithium, with either lead or bismuth, and a third element of zinc, strontium, barium, or copper can reduce the lithium concentration below 20%. In evaluating the overall performance of the blanket coolant, it is important to maintain the lithium concentration at a minimum to reduce chemical reactivity in lithium.
A new technology for a cruise control system (2003)

A methodology for developing a vehicle control software using traffic simulation is presented. A cooperative adaptive cruise control (CACC) system is developed for critical zones using this methodology. Critical zones are short stretches of road, such as intersections, that can be analyzed separately in small-scale simulations, but can have a large effect on the performance of a larger-scale road system such as an interchange. The CACC is shown to outperform human drivers in small and large-scale simulations.
Grid integration of renewable energy sources via virtual synchronous generator (2019)

Ongoing efforts toward environmentally sustainable electricity generation give rise to gradual displacement of synchronous generators by renewable energy resources (RESs). This paradigm shift reshapes power system dynamics and presents numerous challenges to reliable and efficient grid operations. For example, our power system will have reduced inertia and be at higher risk of instability, since the RESs generally interconnect to the grid via power-electronic converters with less or no inertia. Motivated by these challenges arising from RES integration, the concept of virtual synchronous generator (VSG) has been proposed to provide virtual inertia by emulating the SG dynamics in the RES controller. Among all VSG designs, synchronverter is a representative one with concise structure. However, this dissertation finds that conventional synchronverter designs lack in control degrees of freedom, require trial-and-error tuning process, synchronize with the grid slowly, and suffer from output-power coupling. Also, their active-power transfer capacity has not been studied, especially under weak-grid conditions. In order to address these problems and integrate more RESs into our system, my dissertation has five major contributions ranging from control design to tuning method to operation characteristics. First, in order to improve the synchronverter control degrees of freedom, I augment the synchronverter with a damping correction loop, which freely adjusts its response speed without affecting the steady-state performance. In order to simplify the tuning process, I propose a tuning method that evaluates the feasible pole-placement region and directly computes synchronverter parameters to achieve desired dynamics. My proposed tuning method completely avoids the trial-and-error tuning process and thus has overwhelming advantages over conventional tuning methods. Next, in order to synchronize the synchronverter quickly to the grid and enable the flexible ``plug-and-play" operation of RESs, this dissertation proposes a self-synchronizing synchronverter design with both fast self-synchronization speed and easily tuneable parameters. Then, to further improve the tracking performance, I propose a design with reduced output-power coupling. Finally, in order to integrate synchronverter-based RESs in weak grid, this dissertation analytically studies its active power transfer capacity and proposes two countermeasures to improve it. All my proposed designs and analyses are verified through extensive numerical or experimental studies.
On Practical Issues of Electric Network Frequency Based Audio Forensics (2017)

The transmission frequency of power grids, i.e., electric network frequency (ENF), has become a common criterion to authenticate audio recordings during the past decade, drawing much attention from both the academic researchers and law enforcement agencies world widely. The properties of ENF enable forensic applications such as audio evidence timestamp verification and tampering detection. In this paper, based on a general review of existing works, we discuss several important practical problems and facts that have drawn less research attention or have not been formally studied, including ENF detection problems, limitations of the ENF-based tampering detection systems, and the difficulties in the ENF analysis. During ENF detection, the challenges come from not only the noise and the interference, but also the fact that audio recordings without captured ENF can still have signal components in the frequency band of interest (false positive). In ENF-based tampering detection systems, the weakness of commonly used assumptions and the limitations of several existing solutions are discussed. In addition, we reveal that in the most intensively studied ENF-based audio evidence timestamp verification, many works aiming at improving ENF estimation could only produce marginal performance improvement, while the main problems due to noise and interference remain open. All these analysis and discussions are related by a proposed big picture of ENF-based audio authentication systems. After that, we also investigate the strategies to design more reliable audio authentication systems based on the ENF, which consists of a series of research and investigation works.
Photonic integrated circuit implementation of a sub-GHz-selectivity frequency comb filter for optical clock multiplication (2017)

We report a photonic integrated circuit implementation of an optical clock multiplier, or equivalently an optical frequency comb filter. The circuit comprises a novel topology of a ring-resonator-assisted asymmetrical Mach-Zehnder interferometer in a Sagnac loop, providing a reconfigurable comb filter with sub-GHz selectivity and low complexity. A proof-of-concept device is fabricated in a high-index-contrast stoichiometric silicon nitride (Si<sub>3</sub>N<sub>4</sub>/SiO<sub>2</sub>) waveguide, featuring low loss, small size, and large bandwidth. In the experiment, we show a very narrow passband for filters of this kind, i.e. a -3-dB bandwidth of 0.6 GHz and a -20-dB passband of 1.2 GHz at a frequency interval of 12.5 GHz. As an application example, this particular filter shape enables successful demonstrations of five-fold repetition rate multiplication of optical clock signals, i.e. from 2.5 Gpulses/s to 12.5 Gpulses/s and from 10 Gpulses/s to 50 Gpulses/s. This work addresses comb spectrum processing on an integrated platform, pointing towards a device-compact solution for optical clock multipliers (frequency comb filters) which have diverse applications ranging from photonic-based RF spectrum scanners and photonic radars to GHz-granularity WDM switches and LIDARs.
Graphene Oxide Liquid Crystals (2011)

Crystal clear: The liquid crystallinity of graphene oxide platelets in aqueous dispersion is demonstrated. Graphene oxide sheets are arranged around liquid-crystal disclinations (see picture). The orientation of the liquid crystals can be manipulated by a magnetic field or mechanical deformation. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
Stress Integration after Acute and Chronic Predator Stress: Differential Activation of Central Stress Circuitry and Sensitization of the Hypothalamo-Pituitary-Adrenocortical Axis (2003)

Predator exposure is a naturalistic stressor of high ethological relevance. In the current study, our group examined central and peripheral integration of stress responses in rats after acute or repeated exposure to a natural predator (cat). Acute cat exposure rapidly induced hypothalamo-pituitary-adrenocortical (HPA) axis activation and paraventricular nucleus (PVN) CRH mRNA production. Repeated daily cat exposure (7 and 14 d) also up-regulated PVN mRNA CRH expression, but did not result in frank adrenocortical hyperactivity. Unlike other chronic homotypic stress regimens, repeated cat exposure facilitated corticosterone secretion after the 6th or 13th day of exposure. Notably, ACTH secretion and central amygdaloid nucleus CRH mRNA expression were enhanced in animals that were preexposed to the holding chamber relative to chamber-naive rats, suggesting that contextual cues can sensitize subsequent responses to a fearful stimulus. Analysis of c-fos activation was then used to identify brain circuits activated by acute predator stress. Cat exposure elicited a pattern of central c-fos activation that differed substantially from that after either restraint or hypoxia. Predator-specific c-fos mRNA induction was observed in several brain regions comprising the hypothetical brain defense circuit (bed nucleus of the stria terminalis, medial region of the ventromedial nucleus, and dorsal premammillary nucleus). Surprisingly, acute cat exposure did not induce c-fos expression in the PVN. In summary, the data indicate that 1) predation stress invokes a unique stress circuitry that promotes homotypic sensitization of the HPA axis, and 2) familiarization of animals to testing environments can prime central stress pathways to respond robustly to novel threats.
Water-ethanol separation by pervaporation through silk fibroin membranes. (1988)

Silk fibroin membranes which were made insoluble by the treatments in saturated water vapor, in ethanol or in 50% ethanol were investigated for water-ethanol permseparation by pervaporation. Permseparation became effective for the feeds with ethanol concentration ranging up to 90% when the membrane thickness was more than 20μm. The permselectivity was somewhat greater with the membranes treated in water vapor than those treated in ethanolic solutions. Activation energy for permeation obtained from the Arrhenius plots was between 5 and 8kcal/mole. Separation factor for water was slightly smaller in the higher temperature range, and was correlated with the higher flux in the region.
Lysis of primary hepatic tumours by lymphokine activated killer cells. (1987)

Lymphokine activated killer cell is a newly described lytic system against a variety of solid tumours and is distinct in several respects from the classic cytolytic T cell and the natural killer systems. This study was conducted to evaluate the lytic activity of lymphokine activated killer cells against fresh autologous and allogeneic, as well as cultured hepatocellular carcinoma cells. Lymphokine activated killer cell was generated by incubating peripheral blood mononuclear cells with various concentrations of recombinant IL-2 (rIL-2, Cetus, USA) for various periods of time. A four hour 51Cr release assay was used to measure cytotoxicity. The results show that fresh and cultured hepatocellular carcinoma cells were only slightly susceptible to natural killer cells. Normal hepatocytes were resistant to lymphokine activated killer-mediated lysis. Lymphokine activated killer cells could be generated from mononuclear cells of hepatocellular carcinoma patients and normal subjects with lytic activity against fresh autologous and allogeneic and cultured hepatocellular carcinoma cells, but lymphokine activated killer cells from the former was less efficient than that from the latter. It is concluded that the adoptive immunotherapy with combined rIL-2 and lymphokine activated killer may be worth trying in early cases of primary hepatocellular carcinoma.
Synthesis and characterization of new polyamides containing adamantyl and diamantyl moieties in the main chain (1998)

This work synthesized a series of new polyamides by direct polycondensation of 1,3-bis[4-(4-carboxyphenoxy)phenyl]adamantane (I) with various diamines. The diacid I was synthesized from 1,3-bis(4-hydroxyphenyl)adamantane in two steps. Polyamides III were soluble in N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide (DMAc), and pyridine. The polyamides had medium inherent viscosities of 0.30–0.55 dL/g and number-average molecular weights (Mn) of 22,000–36,000. The polyamides IIIa and IIIb had tensile strengths of 59.8 and 77.5 MPa, elongation to breakage values of 5.8 and 7.6%, and initial moduli of 1.9 and 1.8 GPa, respectively. Their glass transition temperatures were found to be 219–295°C by means of differential scanning calorimetry (DSC). Dynamic mechanical analysis (DMA) reveals that the incorporation of rigid and bulky diamantane into polyamides IIIa and IIIb leads to high glass transition temperatures (Tgs), at 299 and 286°C, respectively. The decomposition temperatures of polyamides III at a 5% weight loss ranged from 388 to 416°C in air and from 408 to 435°C in N2 atmosphere. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 785–792, 1998
Expression of endogenously activated secreted or cell surface carboxypeptidase A sensitizes tumor cells to methotrexate-alpha-peptide prodrugs. (2000)

Methotrexate (MTX) is one of the most commonly used agents in the treatment of solid malignancies; however, the toxicities of MTX to bone marrow and gastrointestinal tract complicate this therapy. We, therefore, propose a gene-dependent enzyme prodrug therapy to limit these toxicities by localizing the production of MTX to the site of the tumor. The combination of MTX-alpha-peptide prodrugs, which cannot be internalized by the cellular reduced folate carrier, with carboxypeptidase A (CPA), which can remove the blocking peptide, has been demonstrated previously in vitro using antibody-dependent enzyme prodrug therapy. CPA is normally synthesized as a zymogen that is inactive without proteolytic removal of its propeptide by trypsin. Therefore, to adapt this system to gene-dependent enzyme prodrug therapy, a mutant form of CPA was engineered, CPA(ST3), that does not require trypsin-dependent zymogen cleavage but is instead activated by ubiquitously expressed intracellular propeptidases. Purification, peptide sequencing, and kinetic analysis indicated that mature CPA(ST3) is structurally and functionally similar to the trypsin-activated, wild-type enzyme. In addition, CPA(ST3)-expressing tumors cells were sensitized to MTX prodrugs in a dose- and time-dependent manner. To limit diffusion of CPA, a cell surface localized form was generated by constructing a fusion protein between CPA(ST3) and the phosphatidylinositol linkage domain from decay accelerating factor. SDS-PAGE and flow cytometric analysis of infected tumor cells indicated that CPA(DAF) was cell surface localized. Finally, after retroviral transduction, this enzyme/prodrug strategy exhibited a potent bystander effect, even when <10% of the cells were transduced, because extracellular production of MTX sensitized both transduced and nontransduced cells.
Role of NF‐κB transcription factors in antiinflammatory and proinflammatory actions of mechanical signals (2004)

Magnitude-dependent signals of mechanical strain utilize the NF-kappaB transcription factors as common elements to abrogate or aggravate proinflammatory responses. Furthermore, the intracellular events induced by mechanical overload are similar to those that are initiated by proinflammatory cytokines in arthritis.
Convolutive Blind Source Separation Based on Disjointness Maximization of Subband Signals (2008)

The concept of disjoint component analysis (DCA) is based on the fact that different speech or audio signals are typically more disjoint than mixtures of them. This letter studies the problem of blind separation of convolutive mixtures through the subband-wise maximization of the disjointness of time-frequency representations of the signals. In our approach, we first define a frequency-dependent measure representing the closeness to disjointness of a group of subband signals. Then, this frequency-dependent measure is integrated to form an objective function that only depends on the time-domain parameters of the separation system. Lastly, an efficient natural-gradient-based learning rule is developed for the update of the separation-system coefficients.
The Effects of AlN and Copper Back Side Deposition on the Performance of Etched Back GaN/Si HEMTs (2019)

The breakdown voltage of GaN/Si high-electron-mobility transistors (HEMTs) for power electronics has shown to be improved by removing the silicon substrate. The drawback to this approach is the increase in the device's thermal resistance, which limits the power dissipation that the device can achieve before severe degradation. This letter shows the ability to improve the thermal dissipation of these devices by depositing copper (Cu) below aluminum nitride (AlN) filled etched back GaN-on-Si HEMTs. The device's channel temperature is measured via Raman thermometry. The device's transient thermal dynamics is investigated via transient thermoreflectance imaging, and the temperature profile across the gate metal is monitored. In addition to the device's thermal properties, a residual stress analysis of the GaN channel is performed via photoluminescence. A notable decrease in the tensile residual stress is observed with the removal of the substrate and the addition of the AlN and Cu layers. Overall, the backside copper is shown to decrease the gate temperature of the etched backed AlN filled devices while maintaining a high breakdown voltage.