133 research outputs found

    Pretreatment of Miscanthus giganteus with Lime and Oxidants for Biofuels

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    ACKNOWLEDEGMENTS The authors are grateful to the Energy Biosciences Institute, University of California, Berkeley, Berkeley, CA, for financial support, Dr. Stefan R. Bauer, Valerie D. Mitchell, and Ana Belen Ibanez Zamora for technical assistance, and Jason Cai for fruitful discussions. The authors thank the China Scholarship Council for financial assistance to Fuxin Yang during his stay at University of California, Berkeley.Peer reviewedPostprin

    Synthesized complex-frequency excitation for ultrasensitive molecular sensing

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    Detecting trace molecules remains a significant challenge. Surface-enhanced infrared absorption (SEIRA) based on plasmonic nanostructures, particularly graphene, has emerged as a promising approach to enhance sensing sensitivity. While graphene-based SEIRA offers advantages such as ultrahigh sensitivity and active tunability, intrinsic molecular damping weakens the interaction between vibrational modes and plasmons. Here, we demonstrate ultrahigh-sensitive molecular sensing based on synthesized complex-frequency waves (CFW). Our experiment shows that CFW can amplify the molecular signals (~1.2-nm-thick silk protein layer) detected by graphene-based sensor by at least an order of magnitude and can be universally applied to molecular sensing in different phases. Our approach is highly scalable and can facilitate the investigation of light-matter interactions, enabling diverse potential applications in fields such as optical spectroscopy, metasurfaces, optoelectronics, biomedicine and pharmaceutics.Comment: 21 pages, 4 figure

    Recovering lossless propagation of polaritons with synthesized complex frequency excitation

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    Surface plasmon polaritons and phonon polaritons offer a means of surpassing the diffraction limit of conventional optics and facilitate efficient energy storage, local field enhancement, high sensitivities, benefitting from their subwavelength confinement of light. Unfortunately, losses severely limit the propagation decay length, thus restricting the practical use of polaritons. While optimizing the fabrication technique can help circumvent the scattering loss of imperfect structures, the intrinsic absorption channel leading to heat production cannot be eliminated. Here, we utilize synthetic optical excitation of complex frequency with virtual gain, synthesized by combining the measurements taken at multiple real frequencies, to restore the lossless propagations of phonon polaritons with significantly reduced intrinsic losses. The concept of synthetic complex frequency excitation represents a viable solution to compensate for loss and would benefit applications including photonic circuits, waveguiding and plasmonic/phononic structured illumination microscopy.Comment: 20 pages, 4 figure

    NR2B phosphorylation at tyrosine 1472 contributes to brain injury in a rodent model of neonatal hypoxia-ischemia.

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    Background and purposeThe NR2B subunit of the N-methyl-d-aspartate (NMDA) receptor is phosphorylated by the Src family kinase Fyn in brain, with tyrosine (Y) 1472 as the major phosphorylation site. Although Y1472 phosphorylation is important for synaptic plasticity, it is unknown whether it is involved in NMDA receptor-mediated excitotoxicity in neonatal brain hypoxia-ischemia (HI). This study was designed to elucidate the specific role of Y1472 phosphorylation of NR2B in neonatal HI in vivo and in NMDA-mediated neuronal death in vitro.MethodsNeonatal mice with a knockin mutation of Y1472 to phenylalanine (YF-KI) and their wild-type littermates were subjected to HI using the Vannucci model. Brains were scored 5 days later for damage using cresyl violet and iron staining. Western blotting and immunoprecipitation were performed to determine NR2B tyrosine phosphorylation. Expression of NADPH oxidase subunits and superoxide production were measured in vivo. NMDA-induced calcium response, superoxide formation, and cell death were evaluated in primary cortical neurons.ResultsAfter neonatal HI, YF-KI mice have reduced expression of NADPH oxidase subunit gp91phox and p47phox and superoxide production, lower activity of proteases implicated in necrotic and apoptotic cell death, and less brain damage when compared with the wild-type mice. In vitro, YF-KI mutation diminishes superoxide generation in response to NMDA without effect on calcium accumulation and inhibits NMDA and glutamate-induced cell death.ConclusionsUpregulation of NR2B phosphorylation at Y1472 after neonatal HI is involved in superoxide-mediated oxidative stress and contributes to brain injury

    A protocol of Chinese expert consensuses for the management of health risk in the general public

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    IntroductionNon-communicable diseases (NCDs) represent the leading cause of mortality and disability worldwide. Robust evidence has demonstrated that modifiable lifestyle factors such as unhealthy diet, smoking, alcohol consumption and physical inactivity are the primary causes of NCDs. Although a series of guidelines for the management of NCDs have been published in China, these guidelines mainly focus on clinical practice targeting clinicians rather than the general population, and the evidence for NCD prevention based on modifiable lifestyle factors has been disorganized. Therefore, comprehensive and evidence-based guidance for the risk management of major NCDs for the general Chinese population is urgently needed. To achieve this overarching aim, we plan to develop a series of expert consensuses covering 15 major NCDs on health risk management for the general Chinese population. The objectives of these consensuses are (1) to identify and recommend suitable risk assessment methods for the Chinese population; and (2) to make recommendations for the prevention of major NCDs by integrating the current best evidence and expertsā€™ opinions.Methods and analysisFor each expert consensus, we will establish a consensus working group comprising 40ā€“50 members. Consensus questions will be formulated by integrating literature reviews, expert opinions, and an online survey. Systematic reviews will be considered as the primary evidence sources. We will conduct new systematic reviews if there are no eligible systematic reviews, the methodological quality is low, or the existing systematic reviews have been published for more than 3ā€‰years. We will evaluate the quality of evidence and make recommendations according to the GRADE approach. The consensuses will be reported according to the Reporting Items for Practice Guidelines in Healthcare (RIGHT)
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