A Resonance Model for Spontaneous Cortical Activity

How human brain function emerges from structure has intrigued researchers for decades and numerous models have been put forward, yet none of them yields a close structure-function relation. Here we present a resonance model based on neuronal spike timing dependent plasticity (STDP) principle to describe the spontaneous cortical activity by incorporating the dynamic interactions between neuronal populations into a wave equation, which is able to accurately predict the resting brain functional connectivity (FC), including the resting-state networks. Besides, the proposed model provides strong theoretical and experimental evidences that the spontaneous dynamic coupling between brain regions fluctuates with a low frequency. Crucially, it is able to account for how the negative functional correlations emerge during resonance. We test the model with a large cohort of subjects (1038) from the Human Connectome Project (HCP) S1200 release in both time and frequency domain, which exhibits superior performance to existing eigen-decomposition models

Multitask quantum thermal machines and cooperative effects

Including phonon-assisted inelastic process in thermoelectric devices is able to enhance the performance of nonequilibrium work extraction. In this work, we demonstrate that inelastic phonon-thermoelectric devices have a fertile functionality diagram, where particle current and phononic heat currents are coupled and fueled by chemical potential difference. Such devices can simultaneously perform multiple tasks, e.g., heat engines, refrigerators, and heat pumps. Guided by the entropy production, we mainly study the efficiencies and coefficients of performance of multitask quantum thermal machines, where the roles of the inelastic scattering process and multiple biases in multiterminal setups are emphasized. Specifically, in a three-terminal double-quantum-dot setup with a tunable gate, we show that it efficiently performs two useful tasks due to the phonon-assisted inelastic process. Moreover, the cooperation between the longitudinal and transverse thermoelectric effects in the three-terminal thermoelectric systems leads to markedly improved performance of the thermal machines. While for the four-terminal four-quantum-dot thermoelectric setup, we find that additional thermodynamic affinity furnishes the system with both enriched functionality and enhanced efficiency. Our work provides insights into optimizing phonon-thermoelectric devices.Comment: 14 pages, 7 figure

Possible Luttinger liquid behavior of edge transport in monolayer transition metal dichalcogenide crystals.

In atomically-thin two-dimensional (2D) semiconductors, the nonuniformity in current flow due to its edge states may alter and even dictate the charge transport properties of the entire device. However, the influence of the edge states on electrical transport in 2D materials has not been sufficiently explored to date. Here, we systematically quantify the edge state contribution to electrical transport in monolayer MoS2/WSe2 field-effect transistors, revealing that the charge transport at low temperature is dominated by the edge conduction with the nonlinear behavior. The metallic edge states are revealed by scanning probe microscopy, scanning Kelvin probe force microscopy and first-principle calculations. Further analyses demonstrate that the edge-state dominated nonlinear transport shows a universal power-law scaling relationship with both temperature and bias voltage, which can be well explained by the 1D Luttinger liquid theory. These findings demonstrate the Luttinger liquid behavior in 2D materials and offer important insights into designing 2D electronics

Chemotherapy combined with radiotherapy can benefit more unresectable HCC patients with portal and/or hepatic vein invasion: a retrospective analysis of the SEER database

BackgroundThe purpose of this study is to evaluate the effects of chemotherapy and radiotherapy on the prognosis of unresectable HCC patients with portal and/or hepatic vein invasion.MethodsA retrospective analysis of unresectable HCC patients with portal and/or hepatic vein invasion registered in the Surveillance, Epidemiology, End Results (SEER) database was performed. The propensity score-matching (PSM) method was used to balance differences between groups. Overall survival (OS) and cancer-specific survival (CSS) were the interesting endpoints. OS was calculated from the date of diagnosis to the date of death caused by any cause or the last follow-up. CSS was defined as the interval between the date of diagnosis and date of death due only to HCC or last follow-up. OS and CSS were analyzed by using Kaplan-Meier analysis, Cox proportional hazards model, and Fine-Gray competing-risk model.ResultsA total of 2,614 patients were included. 50.2% patients received chemotherapy or radiotherapy and 7.5% patients received both chemotherapy and radiotherapy. Compared to the untreated group, chemotherapy or radiotherapy (COR) (HR = 0.538, 95% CI 0.495-0.585, p < 0.001) and chemotherapy and radiotherapy (CAR) (HR = 0.371, 95% CI 0.316-0.436, p < 0.001) showed better OS. In the COR group, Cox analysis results showed AFP, tumor size, N stage and M stage were independent risk factor of OS. Competing-risk analysis results showed AFP, tumor size and M stage were independent risk factor of CSS. In the CAR group, AFP and M stage were independent risk factors of OS. Competing-risk analysis results showed M stage were independent risk factor of CSS. Kaplan Meier analysis showed chemotherapy combined with radiotherapy significantly improves OS (10.0 vs. 5.0 months, p < 0.001) and CSS (10.0 vs. 6.0 months, p = 0.006) than monotherapy.ConclusionAFP positive and distant metastasis are the main risk factors affecting OS and CSS of unresectable HCC patients with portal and/or hepatic vein invasion. Chemotherapy combined with radiotherapy significantly improves OS and CSS of unresectable HCC patients with portal and/or hepatic vein invasion

A High-Voltage-Isolated MEMS Quad–Solenoid Transformer with Specific Insulation Barriers for Miniaturized Galvanically Isolated Power Applications

The paper reports on high voltage (HV)-isolated MEMS quad–solenoid transformers for compact isolated gate drivers and bias power supplies. The component is wafer-level fabricated via a novel MEMS micro-casting technique, where the tightly coupled quad–solenoid chip consists of monolithically integrated 3D inductive coils and an inserted ferrite magnetic core for high-efficiency isolated power transmission through electromagnetic coupling. The proposed HV-isolated transformer demonstrates a high inductance value of 743.2 nH, along with a small DC resistance of only 0.39 Ω in a compact footprint of 6 mm2, making it achieve a very high inductance integration density (123.9 nH/mm2) and the ratio of L/R (1906 nH/Ω). More importantly, with embedded ultra-thick serpentine-shaped (S-shaped) SiO2 isolation barriers that completely separate the primary and secondary windings, an over 2 kV breakdown voltage is obtained. In addition, the HV-isolated transformer chips exhibit a superior power transfer efficiency of over 80% and ultra-high dual-phase saturation current of 1.4 A, thereby covering most practical cases in isolated, integrated bias power supplies such as high-efficiency high-voltage-isolated gate driver solutions

How States Become Fragile: Relevancy of State Fragility and Climate Change

The objective of this article is to develop a main index that is capable of determining a state, s fragility and simultaneously measuring the impact of climate change. Six indexes are defined including a dummy one, which are Political Conditions, Economic Conditions, Social Conditions, Demographic Factor, Public Security and State Unrest (dummy). Five non-dummy indexes are involved four sub-indexes respectively. The sum of these six indexes is reported as State Stability Index (SSI). Entropy method and group decision making serve as weighting models to determine weights of sub-indexes and indexes respectively. A state, s fragility is determined by State Fragility Index (SFI), which is the reciprocal of SSI. Five non-dummy indexes and SFI have their standards obtained by K-means, in order to determine whether a state is fragile, vulnerable or stable

How States Become Fragile: Relevancy of State Fragility and Climate Change

The objective of this article is to develop a main index that is capable of determining a state, s fragility and simultaneously measuring the impact of climate change. Six indexes are defined including a dummy one, which are Political Conditions, Economic Conditions, Social Conditions, Demographic Factor, Public Security and State Unrest (dummy). Five non-dummy indexes are involved four sub-indexes respectively. The sum of these six indexes is reported as State Stability Index (SSI). Entropy method and group decision making serve as weighting models to determine weights of sub-indexes and indexes respectively. A state, s fragility is determined by State Fragility Index (SFI), which is the reciprocal of SSI. Five non-dummy indexes and SFI have their standards obtained by K-means, in order to determine whether a state is fragile, vulnerable or stable

EFFECTS OF DILUTE ACID HYDROLYSIS ON COMPOSITION AND STRUCTURE OF CELLULOSE IN EULALIOPSIS BINATA

Dilute sulfuric acid hydrolysis was performed before the isolation of cellulose from Eulaliopsis binata. And then, the effects of dilute acid hydrolysis on composition and structure of the cellulose was studied in detail. The results indicated that hemicellulose was dissolved mostly and that the lignin-hemicellulose-cellulose interactions were also partially disrupted during the dilute acid hydrolysis. Cellulose in Eulaliopsis binata was identified as the cellulose I allomorph with low crystallinity. What’s more, hydrolysis with dilute acid at high temperature increased the degree of cellulose crystallinity and relatively reduced the proportions of less ordered cellulose allomorphs. This was attributed to a preferential degradation of amorphous cellulose and less ordered crystalline forms during the hydrolysis. The cellulose preparation from Eulaliopsis binata after dilute acid hydrolysis had a higher thermal stability than the cellulose preparation from untreated Eulaliopsis binata

MEMS-Casting Fabricated Chip-Style 3D Metal Solenoidal Transformers towards Integrated Power Supply

A silicon-chip-based 3D metal solenoidal transformer is proposed and developed to achieve AC-DC conversion for integrated power supply applications. With wafer-level micro electromechanical systems (MEMS) fabrication technique to form the metal casting mold and the following micro-casting technique to rapidly (within 6 min) fill molten ZnAl alloy into the pre-micromachined silicon mold, 45-turns primary solenoid and 7-turns secondary solenoid are fabricated in silicon wafers, where the two intertwining solenoids are located at inner deck and outer deck, respectively. Permalloy soft magnetic core is inserted into a pre-etched channel in the silicon chip, which is surrounded by the solenoids. The size of the chip-style transformer is as small as 8.5 mm × 6.6 mm × 2.5 mm. The internal resistance of the primary solenoid is 1.82 Ω and that of the secondary solenoid is 0.16 Ω. The working frequency of the transformer is 60 kHz. Combined with the testing circuit of the switch mode power supply, the DC voltage of 13.02 V is obtained when the input is 110 V at 50 Hz/60 Hz. Furthermore, the on-chip 3D solenoidal transformer is used for lighting four LEDs, which shows great potential for AC-DC power supply. The wafer-level fabricated chip-style solenoidal AC-DC transformer for integrated power supply is advantageous in uniform fabrication, small size and volume applications