Ultra-low-loss CMOS-Compatible Waveguide Crossing Arrays Based on Multimode Bloch Waves and Imaginary Coupling

We experimentally demonstrate broadband waveguide crossing arrays showing ultra low loss down to $0.04\,$dB/crossing ($0.9\%$), matching theory, and crosstalk suppression over $35\,$dB, in a CMOS-compatible geometry. The principle of operation is the tailored excitation of a low-loss spatial Bloch wave formed by matching the periodicity of the crossing array to the difference in propagation constants of the 1$^\text{st}$- and 3$^\text{rd}$-order TE-like modes of a multimode silicon waveguide. Radiative scattering at the crossing points acts like a periodic imaginary-permittivity perturbation that couples two supermodes, which results in imaginary (radiative) propagation-constant splitting and gives rise to a low-loss, unidirectional breathing Bloch wave. This type of crossing array provides a robust implementation of a key component enabling dense photonic integration

Game analysis of the knowledge sharing mechanism for the supply chain collaborative innovation

Purpose: In information economy era, innovation is the key to improve the competitiveness of enterprises. The traditional way of enterprise innovation is outdated and supply chain collaborative innovation has becoming popular. This paper aims to analyze the mechanism of knowledge sharing between enterprises in supply chain collaborative innovation. Design/methodology/approach: This paper analyzes the supply chain members’ willingness to share knowledge by using the game theory. The result of knowledge sharing between two companies is analyzed by using the evolutionary game. Findings: We broke the knowledge sharing process in supply chain collaborative innovation into knowledge mining and knowledge transferring. We got the best knowledge sharing strategy of each supply chain member. We gave the influencing factors of knowledge sharing between members for the knowledge sharing mechanisms in supply chain collaborative innovation. Research limitations/implications: We didn’t study the willingness of more than two supply chain members to share knowledge and the result of knowledge sharing between them. And this situation is more realistic. Practical implications: Our findings can help to improve the effect of knowledge sharing in supply chain collaborative innovation.Originality/value: The paper introduces the game theory to knowledge sharing between members in supply chain collaborative innovation, deepens the understanding of knowledge sharing in supply chain collaborative innovation, and gives some interesting findings.Peer Reviewe

On the K-th power mean of one kind generalized cubic Gauss sums

The main purpose of this paper is using the elementary methods and properties of the recurrence sequence to study the calculating problem of the $k$-th power mean of one kind generalized cubic Gauss sums, and give an exact calculating formula for it

Role of the Srs2-Rad51 Interaction Domain in Crossover Control in Saccharomyces cerevisiae.

Saccharomyces cerevisiae Srs2, in addition to its well-documented antirecombination activity, has been proposed to play a role in promoting synthesis-dependent strand annealing (SDSA). Here we report the identification and characterization of an SRS2 mutant with a single amino acid substitution (srs2-F891A) that specifically affects the Srs2 pro-SDSA function. This residue is located within the Srs2-Rad51 interaction domain and embedded within a protein sequence resembling a BRC repeat motif. The srs2-F891A mutation leads to a complete loss of interaction with Rad51 as measured through yeast two-hybrid analysis and a partial loss of interaction as determined through protein pull-down assays with purified Srs2, Srs2-F891A, and Rad51 proteins. Even though previous work has shown that internal deletions of the Srs2-Rad51 interaction domain block Srs2 antirecombination activity in vitro, the Srs2-F891A mutant protein, despite its weakened interaction with Rad51, exhibits no measurable defect in antirecombination activity in vitro or in vivo Surprisingly, srs2-F891A shows a robust shift from noncrossover to crossover repair products in a plasmid-based gap repair assay, but not in an ectopic physical recombination assay. Our findings suggest that the Srs2 C-terminal Rad51 interaction domain is more complex than previously thought, containing multiple interaction sites with unique effects on Srs2 activity

Ultra-low-loss Waveguide Crossing Arrays Based on Imaginary Coupling of Multimode Bloch Waves

Abstract: We experimentally demonstrate ultra-low-loss waveguide crossing arrays showing loss down to 0.04 dB/crossing. They rely on a low loss, focusing Bloch wave that is stabilized by radiative scattering, via a radiative form of coupling. Introduction Silicon photonic circuits promise to enable energy efficient chip-scale photonic interconnects for CPU-to-memory communication. As device density and complexity increase in a planar photonic circuit, efficient waveguide crossings become essential. For some network topologies, the number of waveguide crossings required rises quickly and tolerable levels of loss and crosstalk per crossing accordingly drop to very small limits. A multitude of work has considered crossing designs [1-9], including resonant [1], MMI-like In previous work, Popovic et al. proposed an efficient approach to design a crossing array by constructing a low loss Bloch wave in a matched periodic structure, that avoids contacts, and using non-adiabatic, tapered excitation structures to efficiently excite these low-loss Bloch waves In this paper, we experimentally demonstrate this concept showing near-theoretical performance with loss as low as 0.04 dB/crossing (1%/crossing), and under 0.1 dB measured over a wide wavelength range exceeding 100 nm

Oxidative Stress Activated by Sorafenib Alters the Temozolomide Sensitivity of Human Glioma Cells Through Autophagy and JAK2/STAT3-AIF Axis

The development of temozolomide (TMZ) resistance in glioma leads to poor patient prognosis. Sorafenib, a novel diaryl urea compound and multikinase inhibitor, has the ability to effectively cross the blood-brain barrier. However, the effect of sorafenib on glioma cells and the molecular mechanism underlying the ability of sorafenib to enhance the antitumor effects of TMZ remain elusive. Here, we found that sorafenib could enhance the cytotoxic effects of TMZ in glioma cells in vitro and in vivo. Mechanistically, the combination of sorafenib and TMZ induced mitochondrial depolarization and apoptosis inducing factor (AIF) translocation from mitochondria to nuclei, and this process was dependent on STAT3 inhibition. Moreover, the combination of sorafenib and TMZ inhibited JAK2/STAT3 phosphorylation and STAT3 translocation to mitochondria. Inhibition of STAT3 activation promoted the autophagy-associated apoptosis induced by the combination of sorafenib and TMZ. Furthermore, the combined sorafenib and TMZ treatment induced oxidative stress while reactive oxygen species (ROS) clearance reversed the treatment-induced inhibition of JAK2/STAT3. The results indicate that sorafenib enhanced the temozolomide sensitivity of human glioma cells by inducing oxidative stress-mediated autophagy and JAK2/STAT3-AIF axis

Disrupted neural variability during propofol‐induced sedation and unconsciousness

Variability quenching is a widespread neural phenomenon in which trial‐to‐trial variability (TTV) of neural activity is reduced by repeated presentations of a sensory stimulus. However, its neural mechanism and functional significance remain poorly understood. Recurrent network dynamics are suggested as a candidate mechanism of TTV, and they play a key role in consciousness. We thus asked whether the variability‐quenching phenomenon is related to the level of consciousness. We hypothesized that TTV reduction would be compromised during reduced level of consciousness by propofol anesthetics. We recorded functional magnetic resonance imaging signals of resting‐state and stimulus‐induced activities in three conditions: wakefulness, sedation, and unconsciousness (i.e., deep anesthesia). We measured the average (trial‐to‐trial mean, TTM) and variability (TTV) of auditory stimulus‐induced activity under the three conditions. We also examined another form of neural variability (temporal variability, TV), which quantifies the overall dynamic range of ongoing neural activity across time, during both the resting‐state and the task. We found that (a) TTM deceased gradually from wakefulness through sedation to anesthesia, (b) stimulus‐induced TTV reduction normally seen during wakefulness was abolished during both sedation and anesthesia, and (c) TV increased in the task state as compared to resting‐state during both wakefulness and sedation, but not anesthesia. Together, our results reveal distinct effects of propofol on the two forms of neural variability (TTV and TV). They imply that the anesthetic disrupts recurrent network dynamics, thus prevents the stabilization of cortical activity states. These findings shed new light on the temporal dynamics of neuronal variability and its alteration during anesthetic‐induced unconsciousness.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146388/1/hbm24304_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146388/2/hbm24304.pd