Post-Layout Simulation Driven Analog Circuit Sizing

Post-layout simulation provides accurate guidance for analog circuit design, but post-layout performance is hard to be directly optimized at early design stages. Prior work on analog circuit sizing often utilizes pre-layout simulation results as the optimization objective. In this work, we propose a post-layout-simulation-driven (post-simulation-driven for short) analog circuit sizing framework that directly optimizes the post-layout simulation performance. The framework integrates automated layout generation into the optimization loop of transistor sizing and leverages a coupled Bayesian optimization algorithm to search for the best post-simulation performance. Experimental results demonstrate that our framework can achieve over 20% better post-layout performance in competitive time than manual design and the method that only considers pre-layout optimization

Bioaccumulation of Hg in rice leaf facilitates selenium bioaccumulation in rice (Oryza sativa L.) leaf in the Wanshan mercury mine

Mercury (Hg) bioaccumulation in rice poses a health issue for rice consumers. In rice paddies, selenium (Se) can decrease the bioavailability of Hg through forming the less bioavailable Hg selenides (HgSe) in soil. Rice leaves can directly uptake a substantial amount of elemental Hg from the atmosphere, however, whether the bioaccumulation of Hg in rice leaves can affect the bioaccumulation of Se in rice plants is not known. Here, we conducted field and controlled studies to investigate the bioaccumulation of Hg and Se in the rice-soil system. In the field study, we observed a significantly positive correlation between Hg concentrations and BAFs of Se in rice leaves (r2 = 0.60, p < 0.01) collected from the Wanshan Mercury Mine, SW China, suggesting that the bioaccumulation of atmospheric Hg in rice leaves can facilitate the uptake of soil Se, perhaps through the formation of Hg-Se complex in rice leaves. This conclusion was supported by the controlled study, which observed significantly higher concentrations and BAFs of Se in rice leaf at a high atmospheric Hg site at WMM, compared to a low atmospheric Hg site in Guiyang, SW China

Sulforaphane inhibits the growth of prostate cancer by regulating the microRNA-3919/DJ-1 axis

BackgroundProstate cancer (PCa) is the second most common solid cancer among men worldwide and the fifth leading cause of cancer-related deaths in men. Sulforaphane (SFN), an isothiocyanate compound, has been shown to exert inhibitory effects on a variety of cancers. However, the biological function of SFN in PCa has not been fully elucidated. The objective of this study was conducted to further investigate the possible underlying mechanism of SFN in PCa using in vitro cell culture and in vivo tumor model experiments.MethodsCell viability, migration, invasion, and apoptosis were analyzed by Cell Counting Kit-8 (CCK-8), wound healing assay, transwell assay, or flow cytometry. Expression of microRNA (miR)-3919 was detected by quantitative real-time polymerase chain reaction (qRT-PCR) or in situ hybridization assay. Xenograft assay was conducted to validated the antitumor effect of miR-3919. The targeting relationship between miR-3919 and DJ-1 was verified by dual-luciferase reporter assay. The level of DJ-1was measured by qRT-PCR or western blotting (WB).ResultsIn the present study, SFN downregulated mRNA and protein expression of DJ-1, an oncogenic gene. Small RNA sequencing analysis and dual-luciferase reporter assay confirmed that microRNA (miR)-3919 directly targeted DJ-1 to inhibition its expression. Furthermore, miR-3919 overexpression impeded viability, migration, and invasion and promoted apoptosis of PCa cells. Tumor growth in nude mice was also inhibited by miR-3919 overexpression, and miR-3919 expression in PCa tissues was lower than that in peritumoral tissues in an in situ hybridization assay. Transfection with miR-3919 inhibitors partially reversed the effects of SFN on cell viability, migration, invasion, and apoptosis. ConclusionOverall, the miR-3919/DJ-1 axis may be involved in the effects of SFN on the malignant biological behavior of PCa cells, which might be a new therapeutic target in PCa

A Coupling Mechanism between Flicker Noise and Hot Carrier Degradations in FinFETs

A coupling mechanism between flicker noise and hot carrier degradation (HCD) is revealed in this work. Predicting the flicker noise properties of fresh and aged devices is becoming essential for circuit designs, requiring an understanding of the fundamental noise behaviors. While certain models for fresh devices have been proposed, those for aged devices have not been reported yet because of the lack of a clear mechanism. The flicker noise of aged FinFETs is characterized based on the measure-stress-measure (MSM) method and analyzed from the device physics. It is found that both the mean and deviations of the noise power spectral density increase compared with the fresh counterparts. A coupling mechanism is proposed to explain the trap time constants, leading to the trap characterizations in their energy profiles. The amplitude and number of contributing traps are also changing and are dependent on the mode of HCD and determined by the position of the induced traps. A microscopic picture is developed from the perspective of trap coupling, reproducing well the measured noise of advanced nanoscale FinFETs. The finding is important for accurate flicker noise calculations and aging-aware circuit designs

Cryogenian interglacial greenhouse driven by enhanced volcanism: Evidence from mercury records

An ice-free greenhouse interval (ca. 660 similar to 650 Ma) occurred between the global Sturtian (ca. 717Ma similar to 660Ma) and Marinoan glaciation (ca. 650Ma similar to 635Ma) during the Cryogenian. While volcanic CO2 emissions have been suggested as a trigger for this ice-free interval, evidence for volcanism has been lacking. In this study, spikes in both Hg concentration (76 to 366 ppb) and Hg to total organic carbon ratio (Hg/TOC: 114 to 717 ppb/wt.%) were observed in the Wuhe section of South China, suggesting that extensive volcanic emissions of Hg occurred during the Cryogenian interglacial period. Positive Delta Hg-199 (0.02 to 0.18 parts per thousand) values were observed in these Hg-rich shales, indicating that the volcanic Hg was cycling in the atmosphere, deposited in seawater, and sequestered to sediment via organic matter burial. Combined with other geochemical proxies (e.g., organic carbon isotope and chemical index of alteration), our results provide the first direct evidence that volcanism played a key role in forming the brief Cryogenian interglacial period. (C) 2021 Elsevier B.V. All rights reserved.11Nsciescopu

Integrative Transcriptome and Metabolome Analysis to Reveal Red Leaf Coloration in Shiya Tea (Adinandra nitida)

Background: Adinandra nitida, commonly known as Shiya tea, is a healthcare drink enriched in several phenolic acids and flavonoids, with a purple-red leaf variety possessing a unique flavor and a higher economic value. However, the mechanisms underlying leaf coloration and senescence discoloration remain unknown. Methods: Here, we compared both varieties of A. nitida (purple-red leaf, RL, and green leaf, GL) at two stages of development. To make sure the difference in leaf color in these four groups, several indexes, leaf colorimetric differences, H2O2 content in leaf cells, and antioxidant enzymes activities (superoxide dismutase (SOD), catalase (CAT)) were measured. With the integration of metabolome and transcriptome becoming a trend, metabolites in four groups were detected using an Ultra performance liquid chromatography-tandem mass spectrometer (UPLC-MS/MS) system, and the transcriptome was performed after the extraction of RNA in samples. Afterward, the activities of laccase (LAC) and peroxidase (POD) were measured for further analysis. Results: The deeper or discoloration of leaf color was not caused by the reactive oxygen species (ROS) stress because the H2O2 content was similar for each group. And the SOD and CAT activities improved significantly in young leaves, especially RL_young. Metabolome data showed a large shift in four groups. By focusing on the variation of flavonoids and 1079 metabolites detected in both varieties, along with the accumulation of flavonoids and tannins, proanthocyanins (PAs) were mostly accumulated in young RL. Differential analysis of expressed genes (DEGs) revealed six genes associated with leaf discoloration as hub factors, of which ANRs (ANR1 and ANR2) were positively correlated with the accumulation of PA in RL. Conclusions: Using integrate analysis of metabolome and transcriptome, our results revealed that six structural genes found in proanthocyanin biosynthesis, two reductases (ANR), two oxidative polymerases (POD64, LAC17) and two TFs (bHLH3 and MYB4) related to biosynthesis and polymerization of proanthocyanins were associated with not only the difference of GL and RL but also the faded coloration in two RL groups (RL_young and RL_old), which provided a foundation for further research on an understanding of the regulatory genes and the enzymes specific for proanthocyanidin biosynthesis, facilitating the genetic engineering of crops for beneficial metabolite accumulation