43 research outputs found
Straightforward data transfer in a blockwise dataflow for an analog RRAM-based CIM system
Analog resistive random-access memory (RRAM)-based computation-in-memory (CIM) technology is promising for constructing artificial intelligence (AI) with high energy efficiency and excellent scalability. However, the large overhead of analog-to-digital converters (ADCs) is a key limitation. In this work, we propose a novel LINKAGE architecture that eliminates PE-level ADCs and leverages an analog data transfer module to implement inter-array data processing. A blockwise dataflow is further proposed to accelerate convolutional neural networks (CNNs) to speed up compute-intensive layers and solve the unbalanced pipeline problem. To obtain accurate and reliable benchmark results, key component modules, such as straightforward link (SFL) modules and Tile-level ADCs, are designed in standard 28 nm CMOS technology. The evaluation shows that LINKAGE outperforms the conventional ADC/DAC-based architecture with a 2.07×∼11.22× improvement in throughput, 2.45×∼7.00× in energy efficiency, and 22%–51% reduction in the area overhead while maintaining accuracy. Our LINKAGE architecture can achieve 22.9∼24.4 TOPS/W energy efficiency (4b-IN/4b-W) and 1.82 ∼4.53 TOPS throughput with the blockwise method. This work demonstrates a new method for significantly improving the energy efficiency of CIM chips, which can be applied to general CNNs/FCNNs
Formononetin Administration Ameliorates Dextran Sulfate Sodium-Induced Acute Colitis by Inhibiting NLRP3 Inflammasome Signaling Pathway
Formononetin is a kind of isoflavone compound and has been reported to possess anti-inflammatory properties. In this present study, we aimed to explore the protective effects of formononetin on dextran sulfate sodium- (DSS-) induced acute colitis. By intraperitoneal injection of formononetin in mice, the disease severity of colitis was attenuated in a dose-dependent manner, mainly manifesting as relieved clinical symptoms of colitis, mitigated colonic epithelial cell injury, and upregulations of colonic tight junction proteins levels (ZO-1, claudin-1, and occludin). Meanwhile, our study found that formononetin significantly prevented acute injury of colonic cells induced by TNF-α in vitro, specifically manifesting as the increased expressions of colonic tight junction proteins (ZO-1, claudin-1, and occludin). In addition, the result showed that formononetin could reduce the NLRP3 pathway protein levels (NLRP3, ASC, IL-1β) in vivo and vitro, and MCC950, the NLRP3 specific inhibitor, could alleviate the DSS-induced mice acute colitis. Furthermore, in the foundation of administrating MCC950 to inhibit activation of NLRP3 inflammasome, we failed to observe the protective effects of formononetin on acute colitis in mice. Collectively, our study for the first time confirmed the protective effects of formononetin on DSS-induced acute colitis via inhibiting the NLRP3 inflammasome pathway activation
An epigenetic switch induced by Shh signalling regulates gene activation during development and medulloblastoma growth
The Sonic hedgehog (Shh) signalling pathway plays important roles during development and in cancer. Here we report a Shh-induced epigenetic switch that cooperates with Gli to control transcription outcomes. Before induction, poised Shh target genes are marked by a bivalent chromatin domain containing a repressive histone H3K27me3 mark and an active H3K4me3 mark. Shh activation induces a local switch of epigenetic cofactors from the H3K27 methyltransferase polycomb repressive complex 2 (PRC2) to an H3K27me3 demethylase Jmjd3/Kdm6b-centred coactivator complex. We also find that non-enzymatic activities of Jmjd3 are important and that Jmjd3 recruits the Set1/MLL H3K4 methyltransferase complexes in a Shh-dependent manner to resolve the bivalent domain. In vivo, changes of the bivalent domain accompanied Shh-activated cerebellar progenitor proliferation. Overall, our results reveal a regulatory mechanism that underlies the activation of Shh target genes and provides insight into the causes of various diseases and cancers exhibiting altered Shh signalling
Shear Performance Study of Sleeved Stud Connectors in Continuous Composite Girder
In order to reveal the mechanism of sleeved stud connectors, 15 push-out specimens were designed, and static loading tests were conducted to evaluate the mechanical performance. The shear performance differences between the novel sleeved studs and conventional welded studs were compared. Referring to the experimental results, an Abaqus nonlinear finite element model was established to study the shear mechanism of sleeved stud connectors. Parametric analysis was conducted to investigate the effects of stud height, sleeve filling material, and sleeve diameter on the mechanical performance of the connectors. The experimental and finite element analysis results indicated that the ultimate shear bearing capacity and shear stiffness of the sleeved stud connectors were higher than those of ordinary welded studs, and the maximum slip was relatively small. Compared to conventional welded studs, the ultimate bearing capacity of sleeved studs increased by 4% to 8%, and the shear stiffness increased by 25% to 35%. Since the shear behavior of sleeved studs mainly occurred at the base of the studs, the influence of stud height on shear performance was relatively small. However, sleeve and stud diameter have a great influence on bearing capacity and stiffness. As the Ultra-High Performance Concrete (UHPC) near the base of the stud effectively enhanced the shear carrying capacity of the sleeved stud connectors, the shear carrying capacity and shear stiffness increased with the increase in the sleeve diameter
statetostatequantumdynamicsofthen4sh2x1nhx3h2sreactionanditsreactionmechanismanalysis
Quantum state-to-state dynamics of the N(4~S)+H_2(X~1∑~+)→NH(X~3∑~-)+H(~2S) reaction is reported in an accurate novel potential energy surface constructed by Zhai et al. (2011 J. Chem. Phys. 135 104314). The time-dependent wave packet method, which is implemented on graphics processing units, is used to calculate the differential cross sections. The influences of the collision energy on the product state-resolved integral cross sections and total differential cross sections are calculated and discussed. It is found that the products NH are predominated by the backward scattering due to the small impact parameter collisions, with only minor components being forward and sideways scattered, and have an inverted rotational distribution and no inversion in vibrational distributions; both rebound and stripping mechanisms exist in the case of high collision energies
Mitogen-stimulated cell proliferation and cytokine production in major depressive disorder patients
Abstract Background Major depressive disorder (MDD) is related to human’s immune status, and immunological indicators such as mitogen stimulated cell proliferation and cytokines may become candidate biomarkers for disease diagnosis. Methods One hundred diagnosed major depressive disorder subjects and 100 health controls were enrolled in this study. Phytohaemagglutinin and lipopolysaccharide stimulated cell proliferations and cytokine concentrations were detected in peripheral blood mononuclear cells from both groups. The corresponding stimulated responses were conducted and confirmed in chronic unpredictable mild stress (CUMS) mice. Results Compared to the people in control group, there were lower cell proliferations and lower TNF-α produced in lipopolysaccharide stimulated peripheral blood mononuclear cells in depression patients, lower IL-2 and IL-10 produced in phytohaemagglutinin stimulated peripheral blood mononuclear cells in depression patients, higher IL-6, IL-10 and lower IL-2 secretions were detected in peripheral plasma in depression patients. In CUMS mice we found lower splenocyte proliferations, lower IL-1α productions and higher IL-6 secretions in lipopolysaccharide stimulated splenocytes. It seems lipopolysaccharide stimulated cell proliferation activities were inhibited in depressive states. Conclusions Lower lipopolysaccharide stimulated cell proliferation and phytohaemagglutinin stimulated or plasma cytokine IL-2 decreases should be potential monitoring indices in the depressive state assessment for major depressive disorder patients
statetostatequantumdynamicsofthen4sh2x1nhx3h2sreactionanditsreactionmechanismanalysis
Quantum state-to-state dynamics of the N(4~S)+H_2(X~1∑~+)→NH(X~3∑~-)+H(~2S) reaction is reported in an accurate novel potential energy surface constructed by Zhai et al. (2011 J. Chem. Phys. 135 104314). The time-dependent wave packet method, which is implemented on graphics processing units, is used to calculate the differential cross sections. The influences of the collision energy on the product state-resolved integral cross sections and total differential cross sections are calculated and discussed. It is found that the products NH are predominated by the backward scattering due to the small impact parameter collisions, with only minor components being forward and sideways scattered, and have an inverted rotational distribution and no inversion in vibrational distributions; both rebound and stripping mechanisms exist in the case of high collision energies
Weighted Synapses Without Carry Operations for RRAM-Based Neuromorphic Systems
The parallel updating scheme of RRAM-based analog neuromorphic systems based on sign stochastic gradient descent (SGD) can dramatically accelerate the training of neural networks. However, sign SGD can decrease accuracy. Also, some non-ideal factors of RRAM devices, such as intrinsic variations and the quantity of intermediate states, may significantly damage their convergence. In this paper, we analyzed the effects of these issues on the parallel updating scheme and found that it performed poorly on the task of MNIST recognition when the number of intermediate states was limited or the variation was too large. Thus, we propose a weighted synapse method to optimize the parallel updating scheme. Weighted synapses consist of major and minor synapses with different gain factors. Such a method can be widely used in RRAM-based analog neuromorphic systems to increase the number of equivalent intermediate states exponentially. The proposed method also generates a more suitable ΔW, diminishing the distortion caused by sign SGD. Unlike when several RRAM cells are combined to achieve higher resolution, there are no carry operations for weighted synapses, even if a saturation on the minor synapses occurs. The proposed method also simplifies the circuit overhead, rendering it highly suitable to the parallel updating scheme. With the aid of weighted synapses, convergence is highly optimized, and the error rate decreases significantly. Weighted synapses are also robust against the intrinsic variations of RRAM devices
Assessment of the Effect of Organic Matter on Rare Earth Elements and Yttrium Using the Zhijin Early Cambrian Phosphorite as an Example
The geochemistry of rare earth elements and yttrium (REY) in phosphorite has been widely studied. However, the effect of organic matter on REY enrichment has not been well determined. We utilized paired inorganic (δ13Ccarb) and organic (δ13Ccarb) carbon isotopes, total organic carbon (TOC), and REY content (∑REY) of the Zhijin Motianchong (MTC) phosphorite and compared them with those of Meishucun (MSC) phosphorite to reveal the effect of organic matter on REY. The δ13Ccarb of the MTC area (≈0‰) is heavier than that of the MSC area (−5.23‰ to −1.13‰), whereas δ13Corg is lighter (−33.85‰ to −26.34‰) in MTC than in MSC (−32.95‰ to −25.50‰). Decoupled δ13Ccarb and δ13Corg in MTC indicate the contribution of chemoautotrophic organisms or methanotrophic bacteria. Compared to the MSC phosphorite, the MTC phosphorite has higher ∑REY and TOC, and these parameters have a positive relationship. MTC phosphorite has REY patterns resembling those of contemporary organic matter. Furthermore, dolomite cement has a higher ∑REY than dolomite in the phosphorus-bearing dolostone. Additionally, pyrites are located on the surface of fluorapatite in the Zhijin phosphorites. It is reasonable to suggest that the REY was released into the pore water owing to the anaerobic oxidation of organic matter at the interface between seawater and sediment, resulting in the REY enrichment of Zhijin phosphorites
Thermally Stable Guest-Host Polyetherketone Poled Polymer for Electro-Optical Applications
The high glass transition temperature polymer polyetherketone doped with disperse red 13 (DR13/PEK-c) has been prepared by the spin-coating method. Through in situ second-harmonic generation, the corona poling temperature was optimized by measuring the temperature dependence of the in situ second-harmonic generation signal intensity under the poling electric field. The linear electro-optic coefficients of the poled polymer films have been determined at 632.8 nm by using a simple interferometric technique. The polymer system was measured after 13 000 h, and found that it remained at 80% of its initial value