gebhart/patrepeval huggingface dataset:
A novel RNA structural motif in the selenocysteine insertion element of eukaryotic selenoprotein mRNAs. (1996)

In eukaryotes, co-translational insertion of selenocysteine into selenoproteins necessitates the participation of the selenocysteine insertion sequence (SECIS), an element lying in the 3'-untranslated region of selenoprotein mRNAs. We report a detailed experimental study of the secondary structures of the SECIS elements of three selenoprotein mRNAs, the rat and human type I iodothyronine deiodinase (5'DI) and rat glutathione peroxidase (GPx). Based on RNase and chemical probing, a new secondary structure model is established. It is characterized by a stem-loop structure, comprising two helices (I and II) separated by an internal loop, with an apical loop surmounting helix II. Sequence comparisons of 20 SECIS elements, arising from 2 5'DI, 13 GPx, 2 selenoprotein P, and 1 selenoprotein W mRNAs, confirm the secondary structure model. The most striking finding of the experimental study concerns a set of conserved sequences in helix II that interact to form a novel RNA structural motif consisting of a quartet composed of non-Watson-Crick base pairs 5'UGAY3': 5'UGAU3'. The potential for forming the quartet is preserved in 15 SECIS elements, but three consecutive non-Watson-Crick base pairs can nevertheless form in the other five SECIS, the central G.A tandem being invariant in all cases. A 3D model, derived by computer modeling with the use of the solution data, suggests that the base pairing interactions in the G.A tandem are of the type found in GNRA loops. The 3D model displays the quartet lying in an accessible position at the foot of helix II, which is bent at the internal loop, suggesting that the non-Watson-Crick base pair arrangement provides an unusual pattern of chemical groups for putative ligand interaction.
Trade-off evaluation in embedded system design via co-simulation (2002)

Current design methodologies for embedded systems often force the designer to evaluate early in the design process architectural choices that will heavily impact the cost and performance of the final product. Examples of these choices are hardware/software partitioning, choice of the micro-controller, and choice of a run-time scheduling method. This paper describes how to help the designer in this task, by providing a flexible co-simulation environment in which these alternatives can be interactively evaluated.
A low-complexity image compression algorithm for Address-Event Representation (AER) PWM image sensors (2011)

In Pulse-Width Modulation (PWM) image sensors the incident light intensity is represented by the timing of pulses. Exceptionally high dynamic range (DR) and improved signal-to- noise-ratio (SNR) have been demonstrated for this class of image sensors. Unfortunately, their spatial resolution is limited by the need of an in-pixel memory to record the timing information. The AER protocol is an attractive method for removing this overhead, since pixel trigger events can be sent as address vectors, and in- pixel data memories are no longer required. Regrettably, the need to send address vectors can place an increased burden on the communication channel and will limit the array resolution, frame-rate, and image quality. In this paper, we present a low- complexity AER Block Compression (AERBC) algorithm which exploits the statistically ordered nature of AER pixel arrays. The address vector overhead can be dramatically reduced under this scheme. Only 0.0625 comparisons and 0.125 subtractions are performed for each pixel, and on average 30.82 dB PSNR can be achieved at 1.0 bit-per-pixel code rate. A general strategy is also developed here to optimize AERBC parameters so a balance between performance and hardware resources can be reached.
A digital neural network architecture for VLSI (1990)

An approach to solving the two most serious shortcomings of previous artificial neural network implementations is discussed. A flexible architecture that permits the realization of arbitrary network topologies and dimensions is presented. Furthermore, the performance of this architecture is independent of the size of the network and permits the processing of typically 100000 patterns per second. The key innovation is the representation of neuron activations and synaptic weights as stochastic functions of time, leading to efficient implementations of the synapses. High densities of synapses per silicon area, exceeding even analog implementations, have been achieved. Finally, the neuron activations are represented digitally, as are the synaptic computations, thereby permitting fabrication of digital neural network architectures using a variety of standard, low-cost semiconductor processes. A pair of general-purpose chips (SU3232 and NU32) that permit post facto construction of neural networks of arbitrary topology and virtually unlimited dimensions is presented
Optically-Gated Self-Calibrating Nanosensors: Monitoring pH and Metabolic Activity of Living Cells (2013)

Quantitative detection of biological and chemical species is critical to numerous areas of medical and life sciences. In this context, information regarding pH is of central importance in multiple areas, from chemical analysis, through biomedical basic studies and medicine, to industry. Therefore, a continuous interest exists in developing new, rapid, miniature, biocompatible and highly sensitive pH sensors for minute fluid volumes. Here, we present a new paradigm in the development of optoelectrical sensing nanodevices with built-in self-calibrating capabilities. The proposed electrical devices, modified with a photoactive switchable molecular recognition layer, can be optically switched between two chemically different states, each having different chemical binding constants and as a consequence affecting the device surface potential at different extents, thus allowing the ratiometric internal calibration of the sensing event. At each point in time, the ratio of the electrical signals measured in the ground and excited states, respectively, allows for the absolute concentration measurement of the molecular species under interest, without the need for electrical calibration of individual devices. Furthermore, we applied these devices for the real-time monitoring of cellular metabolic activity, extra- and intracellularly, as a potential future tool for the performance of basic cell biology studies and high-throughput personalized medicine-oriented research, involving single cells and tissues. This new concept can be readily expanded to the sensing of additional chemical and biological species by the use of additional photoactive switchable receptors. Moreover, this newly demonstrated coupling between surface-confined photoactive molecular species and nanosensing devices could be utilized in the near future in the development of devices of higher complexity for both the simultaneous control and monitoring of chemical and biological processes with nanoscale resolution control.
Processor Aware Anticipatory Prefetching in Loops (2005)

As microprocessor speeds increase, a large fraction of the execution time is often lost to cache miss penalties. This loss can be particularly severe in processors such as the UltraSPARC-IIICu which have in-order execution and block on cache misses. Such processors rely greatly on the compiler to reduce stalls and achieve high performance. This paper describes a compiler technique for software prefetching that is aware of the specific prefetch behaviors of the target processor. The implementation targets loops containing control-flow and strided or irregular memory access patterns. A two phase locality analysis, capable of handling complex subscript expressions, is used for enhanced identification of prefetch candidates. Prefetch instructions are scheduled with careful consideration of the prefetch behaviors in the target system. Compared to a previous implementation, our technique produced performance improvements of 9% on the geometric mean, and up to 44% on individual tests, in Sun’s first UltraSPARC-IIICu based SPEC CPU2000 submission [5] and has been used in all later submissions to date.
Curcumin-loaded nanoparticles enhance apoptotic cell death of U2OS human osteosarcoma cells through the Akt-Bad signaling pathway (2013)

Curcumin has potential anticancer activity and has been shown to be involved in several signaling pathways including differentiation and apoptosis. Our previous study showed that water-soluble PLGA curcumin nanoparticles (Cur-NPs) triggered apoptotic cell death through regulation of the function of MDR1 and the production of reactive oxygen species (ROS) in cisplatin-resistant human oral cancer CAR cells. In this study, we investigated the anti-proliferative effects of Cur-NPs on human osteosarcoma U2OS cells. The morphology of Cur-NPs showed spherical shape by TEM analysis. The encapsulation efficiency of curcumin in Cur-NPs prepared by single emulsion was 90.5 ± 3.0%. Our results demonstrated that the curcumin fragments on the mass spectrum of Cur-NPs and the peaks of curcumin standard could be found on the Cur-NPs spectrum by 1H-NMR spectra analysis. Cur-NPs induced anti-proliferative effects and apoptosis in U2OS cells. Compared to the untreated U2OS cells, more detectable amount of Cur-NPs was found inside the treated U2OS cells. Cur-NPs induced DNA fragmentation and apoptotic bodies in U2OS cells. Both the activity and the expression levels of caspases-3/-7 and caspase-9 were elevated in the treated U2OS cells. Cur-NPs upregulated the protein expression levels of cleaved caspase-3/caspase-9, cytochrome c, Apaf-1 and Bad and downregulated the protein expression level of p-Akt in U2OS cells. These results suggest Cur-NPs are effective in enhancing apoptosis in human osteosarcoma cells and thus could provide potential for cancer therapeutics.
Group-theoretic approach to enhancing the Fourier modal method for crossed gratings with square symmetry (2006)

The Fourier modal method for crossed gratings with square symmetry is reformulated by use of a group-theoretic approach that we developed recently. In the new formulation, a crossed-grating problem is decomposed into six symmetrical basis problems whose field distributions are the symmetry modes of the grating. Then the symmetrical basis problems are solved with symmetry simplifications, whose solutions are superposed to get the solution of the original problem. Theoretical and numerical results show that when the grating is at some Littrow mountings, the computation efficiency can be improved effectively: The memory occupation is reduced by 3/4 and the computation time is reduced by a factor from 25.6 to 64 in different incident cases. Numerical examples are given to show the effectiveness of the new formulation.
The phasevarion: A genetic system controlling coordinated, random switching of expression of multiple genes (2005)

Several host-adapted bacterial pathogens contain methyltransferases associated with type III restriction-modification (R-M) systems that are subject to reversible, high-frequency on/off switching of expression (phase variation). To investigate the role of phase-variable expression of R-M systems, we made a mutant strain lacking the methyltransferase (mod) associated with a type III R-M system of Haemophilus influenzae and analyzed its phenotype. By microarray analysis, we identified a number of genes that were either up- or down-regulated in the mod mutant strain. This system reports the coordinated random switching of a set of genes in a bacterial pathogen and may represent a widely used mechanism.
Postoperative utilization of critical care services by cardiac surgery (1993)

Significant differences exist among hospitals in the same healthcare system in the utilization of critical care services for cardiac surgery. In spite of these differences, for similar patient "input," the outcome (mortality and hospital lengths of stay) appeared similar. Assessments of utilization of critical care must focus on more detailed specific issues than unit length of stay, and must include factors such as availability of intermediate care areas, the unit management system, chronic health status, and the operative procedures performed, if a utilization management process is to effect improved resource use in critical care.
Polarization spectroscopy of rubidium atoms: Theory and experiment (2008)

We present a theoretical and experimental study of polarization spectroscopy of rubidium atoms. All of the populations of the magnetic sublevels were calculated from the rate equations and used in the calculation of the polarization spectroscopy spectra. Using this model, we could generate theoretical line shapes of the polarization spectra on the ${D}_{2}$ transitions of rubidium atoms. The experimental results demonstrated that our model accurately reproduced spectra for all transitions in hyperfine structures.
A MECHANISM FOR THE REACTION OF ORGANIC HALIDES WITH SULFIDES. SULFONIUM COMPOUNDS. I (1937)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA MECHANISM FOR THE REACTION OF ORGANIC HALIDES WITH SULFIDES. SULFONIUM COMPOUNDS. IFRANCIS EARL RAY and IRVING LEVINECite this: J. Org. Chem. 1937, 02, 3, 267–275Publication Date (Print):July 1, 1937Publication History Published online1 May 2002Published inissue 1 July 1937https://pubs.acs.org/doi/10.1021/jo01226a009https://doi.org/10.1021/jo01226a009research-articleACS PublicationsRequest reuse permissionsArticle Views190Altmetric-Citations8LEARN 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-Alertsclose Get e-Alerts
The Inhibitory Effect of Clindamycin on <i>Lactobacillus in vitro</i> (2001)

High concentrations of clindamycin achieved in the vagina by intravaginal application might be inhibitory for Lactobacillus.
Platooning Maneuvers in Vehicular Networks: A Distributed and Consensus-Based Approach (2018)

Cooperative driving is an essential component of future intelligent road systems. It promises greater safety, reducing accidents due to drivers distraction, improved infrastructure utilization, and fuel consumption reduction with platooning applications. Proper platoon management requires inter-vehicular communication (IVC), longitudinal control and lateral control for stability and safety, and proper application protocols and algorithms to manage platoons and perform coordinated maneuvers. This paper shows, how a longitudinal controller based on distributed consensus can, at the same time, guarantee stability and performance in regime platoon operations, and be at the hearth of maneuvering protocols and algorithms, as it remains stable in face of changes of platoon topology and control gains. The adoption of a single control algorithm for two fundamental tasks greatly simplify the overall design of the system and improves stability and safety as it is not required to switch between different controllers during platoon operation. The theoretical properties are proven in the first part of the paper. The second part of the paper is devoted to its implementation in a state-of-the-art mobility and IVC simulator, which is used for an extensive experimental campaign showing the dynamic properties of the system and its performance in a set of typical platoon maneuvers as join, leave, and inclusion of a vehicle in the middle of the platoon. All simulations include realistic details of the vehicle dynamics (mass, dimensions, power train dynamics) as well as extremely detailed modeling of the communication network, from IEEE 802.11p protocol details, to collisions, packet errors, path loss and fading on the channel, and source-destination-based delays.
Combination of ruthenium(II)-arene complex [Ru(η6-p-cymene)Cl2(pta)] (RAPTA-C) and the epidermal growth factor receptor inhibitor erlotinib results in efficient angiostatic and antitumor activity (2017)

Ruthenium-based compounds show strong potential as anti-cancer drugs and are being investigated as alternatives to other well-established metal-based chemotherapeutics. The organometallic compound [Ru(η<sup>6</sup>-p-cymene)Cl<sub>2</sub>(pta)], where pta = 1,3,5-triaza-7-phosphaadamantane (RAPTA-C) exhibits broad acting anti-tumor efficacy with intrinsic angiostatic activity. In the search for an optimal anti-angiogenesis drug combination, we identified synergistic potential between RAPTA-C and the epidermal growth factor receptor (EGFR) inhibitor, erlotinib. This drug combination results in strong synergistic inhibition of cell viability in human endothelial (ECRF24 and HUVEC) and human ovarian carcinoma (A2780 and A2780cisR) cells. Additionally, erlotinib significantly enhances the cellular uptake of RAPTA-C relative to treatment with RAPTA-C alone in human ovarian carcinoma cells, but not endothelial cells. Drug combinations induce the formation of chromosome bridges that persist after mitotic exit and delay abscission in A2780 and A2780cisR, therefore suggesting initiation of cellular senescence. The therapeutic potential of these compounds and their combination is further validated in vivo on A2780 tumors grown on the chicken chorioallantoic membrane (CAM) model, and in a preclinical model in nude mice. Immunohistochemical analysis confirms effective anti-angiogenic and anti-proliferative activity in vivo, based on a significant reduction of microvascular density and a decrease in proliferating cells.
Static and dynamic forward stability of occupied wheelchairs: influence of elevated footrests and forward stabilizers. (1989)

With 20 able-bodied subjects, three hypotheses were tested: (1) that elevating the footrests reduces the forward stability of occupied wheelchairs, (2) that placing simulated plaster casts on the occupant's legs further reduces stability, and (3) that forward stabilizers limit the extent of dynamic forward instability. Static stability was studied on a tilting platform; dynamic stability was tested by having subjects descend a ramp. Elevating one or both footrests and adding one or two simulated casts each significantly reduced static forward stability. During dynamic testing with lowered footrests, only seven subjects tipped forward, and the extent of tip was limited by the footrests. With both footrests elevated, eight subjects tipped transiently, and 12 continued to tip until the footrests hit the floor. With the addition of simulated casts, all 20 subjects tipped fully. Elevating one footrest (with or without a cast) caused only transient tips. On a high-friction floor surface, 19 and 18 subjects (with and without casts) experienced full tips or yawing falls to the side of the elevated footrest. The addition of forward stabilizers prevented wheelchairs from full tips or falls, when the users had both legs elevated, or when one of the users' legs (p less than 0.005), was elevated while located on a high friction floor (p less than 0.005). These findings have implications for wheelchair design and prescription.
Allosteric Control of Gating and Kinetics at P2X<sub>4</sub>Receptor Channels (1999)

The CNS abundantly expresses P2X receptor channels for ATP; of these the most widespread in the brain is the P2X(4) channel. We show that ivermectin (IVM) is a specific positive allosteric effector of heterologously expressed P2X(4) and possibly of heteromeric P2X(4)/P2X(6) channels, but not of P2X(2), P2X(3), P2X(2)/P2X(3,) or P2X(7) channels. In the submicromolar range (EC(50,) approximately 250 nM) the action of IVM was rapid and reversible, resulting in increased amplitude and slowed deactivation of P2X(4) channel currents evoked by ATP. IVM also markedly increased the potency of ATP and that of the normally low-potency agonist alpha, beta-methylene-ATP in a use- and voltage-independent manner without changing the ion selectivity of P2X(4) channels. Therefore, IVM evokes a potent pharmacological gain-of-function phenotype that is specific for P2X(4) channels. We also tested whether IVM could modulate endogenously expressed P2X channels in the adult trigeminal mesencephalic nucleus and hippocampal CA1 neurons. Surprisingly, IVM produced no significant effect on the fast ATP-evoked inward currents in either type of neuron, despite the fact that IVM modulated P2X(4) channels heterologously expressed in embryonic hippocampal neurons. These results suggest that homomeric P2X(4) channels are not the primary subtype of P2X receptor in the adult trigeminal mesencephalic nucleus and in hippocampal CA1 neurons.
[Effect of artemisinin on ischemia/reperfusion injury of isolated rat myocardium]. (2007)

AS (10, 100 micromol x L(-1)) alleviate the myocardial ischemia/reperfusion injury in rats. The mechanism may be related to its functions of antioxidation and scavenging free radicals.
Nematic molecular core flexibility and chiral induction (2013)

Electroclinic measurements, in which an applied electric field E induces a rotation Δθ ([proportional]E) of the liquid crystal director about the electric field axis in a chiral environment, were performed on several configurationally achiral liquid crystals in the presence of an imposed helical director profile. This imposed twist establishes a chiral symmetry environment for the liquid crystal. It was observed that a conformationally racemic mesogen possessing a flexible phenyl benzoate core exhibits a measurable electroclinic response in the nematic phase. On the other hand, when the phenyl benzoate mesogen is mixed with a mesogen containing a rigid, conformationally achiral core (fluorenone), or with a racemic dopant with an axially chiral core that mimics a mesogen having rigid right- and left-handed conformations (2,2'-spirobiindan-1,1'-dione), the magnitudes of the electroclinic responses were found to decrease sharply, apparently going to zero when extrapolated to the pure 2,2'-spirobiindan-1,1'-dione or fluorenone limit. (Note that neither of these additives possesses a nematic phase.). The results suggest that the flexibility of the core and its ability to deracemize conformationally in order to compensate the elastic energy cost of the imposed twist is the primary mechanism behind the observed electroclinic response.