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1.
Environ Sci Pollut Res Int ; 31(28): 41155-41166, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38849618

RESUMO

Zinc and cadmium ions are usually found in livestock breeding wastewater, and the mixed ions will have an impact on the biological nitrogen removal. Nitrification performance plays an important role in biological nitrogen removal. In order to investigate the combined effect of zinc and cadmium ions on nitrification performance and to reveal the interactions between zinc and cadmium ions, three concentration ratios of zinc and cadmium ions, as well as 18 different concentration gradients were designed with the direct equipartition ray and the dilution factor method. The effect of pollutants on the nitrification performance of biological nitrogen removal was analyzed by the nonlinear regression equation, and the concentration-addition model was conducted to probe into the relationship between the mixed pollutants and the nitrification performance. The results showed that the effect on nitrification performance increased significantly with the increase of reaction duration and pollutant concentration, which indicated that the effects are concentration-dependent and time-dependent. The concentration-addition model suggested that the interactions between zinc and cadmium ions with different concentration ratios were mainly antagonistic, and as the percentage of cadmium ions in the mixtures increased, the antagonism between the mixtures became stronger. This study will provide a relevant theoretical basis for the regulation of the ratios and concentrations of heavy metal ions during the biological treatment of livestock breeding wastewater.


Assuntos
Cádmio , Gado , Nitrificação , Nitrogênio , Águas Residuárias , Zinco , Animais , Águas Residuárias/química , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água
2.
Curr Res Food Sci ; 8: 100670, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38261894

RESUMO

The effects of co-fermentation of yeast and Lactiplantibacillus plantarum 104 on buckwheat starch physical properties were investigated by various analytical techniques. To investigate the regulations of starch modification during fermentation and to provide a foundation for improving the performance of modified properties of buckwheat starch food. The pasting properties were decreased by co-fermentation also resulted in a reduction in the relative crystallinity. Scanning electron microscopy (SEM) demonstrated that more holes and a relatively rough granule surface were seen in the co-fermentation group. Fourier transform-infrared spectroscopy (FT-IR) results suggested that co-fermentation fermentation decreased the degree of short-range order (DO) and degree of t1he double helix (DD). The results demonstrated that co-fermentation altered these properties more rapidly than spontaneous fermentation. In conclusion, Lactiplantibacillus plantarum 104 could be used for buckwheat fermentation to improve food quality.

3.
J Environ Manage ; 351: 119909, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38154224

RESUMO

Complemented croplands are a crucial component of cropland resources and play a significant role in ensuring national food security. In recent decades, to counter the loss of prime farmland caused by urban construction, the Chinese government introduced a requisition-compensation balance policy, leading to the substantial expansion of new croplands. Therefore, there is an urgent need to determine whether these complemented croplands can be effectively used. Taking Southwest China as a case study, we used high-precision long-term land-use data from 1990 to 2020 to reveal the dynamics of complemented cropland utilization, evaluate the efficiency of complemented cropland utilization from the perspective of abandoned farmland, and identify the factors driving complemented cropland use efficiency based on more than 13 million land parcels. The results showed that: (1) From 1990 to 2020, complemented cropland amounted to approximately 1170.07 × 104 hm2, accounting for 32.67% of the total arable land area in 1990. The potential grain production capacity of these complemented croplands was significantly lower than that of base croplands. (2) The abandonment of complemented croplands was more serious than that of base croplands, and 47.03% of the complemented croplands experienced abandonment at least once during the study period, and the average efficiency of the complemented croplands was 75.61%. (3) The labor population ratio, elevation, and land parcel size played pivotal roles in influencing the complemented cropland utilization efficiency; however, there was substantial variation among the different provinces. Labor replacement, overcoming farming difficulties brought by mountainous terrain, and improving farmers' income are the keys to alleviating cropland abandonment in mountainous areas and improving cropland utilization efficiency. This study provides novel insights into the efficiency assessment and exploration of the mechanisms driving complemented croplands and can provide references for cropland management.


Assuntos
Agricultura , Conservação dos Recursos Naturais , Conservação dos Recursos Naturais/métodos , Agricultura/métodos , Fazendas , Grão Comestível , China
4.
Langmuir ; 39(46): 16244-16260, 2023 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-37935578

RESUMO

The interfacial bonding of the four cellulose nanocrystals (CNCs) and calcium silicate hydrate (C-S-H) in vacuum and solution conditions was analyzed by molecular dynamics simulation. The binding energies were calculated, and the sources of interface strength were analyzed by the formation and lifetime of hydrogen bonds. The adsorption between CNC/C-S-H was characterized by the movement of interfacial atoms and CNC's adsorption conformation. The types of the functional group determine the bonding of the CNC/C-S-H, and the interface adsorption in two simulation conditions both followed: CNC-C (carboxyl) > CNC-O (hydroxyl) > CNC-N (amino) > CNC-S (sulfonic). The bonding of the interface affects the load transferred between the matrix and CNC, which can be reflected in the overall mechanical properties of the mortar. The mechanical strength of the mortar is in line with the simulation results. CNC-C has the strongest reinforcement effect, while CNC-S has the weakness effect. In the solution simulation, there is almost no chemical adsorption between C-S-H and CNC-S; instead, CNC-S decreased the bonding between the matrix and reduced the strength of the sample. Scanning electron microscopy found that CNC was interspersed in the matrix, riveting the matrix and enhanced the stability of the mortar structure. The influence of CNC on the mortar structure was analyzed by the calcium to silicon ratio (C/S) and it was showed that CNC-C, CNC-O, and CNC-N have an enhancement effect, while CNC-S decreased the coherence of the cement matrix. Durability and nuclear magnetic resonance tests further verified the effect of the four CNCs on the structure of mortar, and results indicated that CNC-C, CNC-O, and CNC-N can control the growth of hydration crystals, fill the cracks, and reduced porosity of samples, while CNC-S reduces the compactness of hydration products and ultimately decreased the mechanical and durability properties of the mortar.

5.
ACS Appl Mater Interfaces ; 15(27): 32075-32086, 2023 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-37368492

RESUMO

Vertically stacked artificial 2D superlattice hybrids fabricated through molecular-level hybridization in a controlled fashion play a vital role in scientific and technological fields, but developing an alternate assembly of 2D atomic layers with strong electrostatic interactions could be much more challenging. In this study, we have constructed an alternately stacked self-assembled superlattice composite through integration of CuMgAl layered double hydroxide (LDH) nanosheets having positive charge with negatively charged Ti3C2Tx layers using well-controlled liquid-phase co-feeding protocol and electrostatic attraction and investigated its electrochemical performance in sensing early cancer biomarkers, i.e., hydrogen peroxide (H2O2). The molecular-level CuMgAl LDH/Ti3C2Tx superlattice self-assembly possesses superb conductivity and electrocatalytic properties, which are significant for obtaining a high electrochemical sensing aptitude. Electron penetration in Ti3C2Tx layers and rapid ion diffusion along 2D galleries have shortened the diffusion path and enhanced the charge transferring efficacy. The electrode modified with the CuMgAl LDH/Ti3C2Tx superlattice has demonstrated admirable electrocatalytic abilities in H2O2 detection with a wide linear concentration range and low real-time limit of detection (LOD) of 0.1 nM with signal/noise ratio (S/N) = 3. Practically, an electrochemical sensing podium based on the CuMgAl LDH/Ti3C2Tx superlattice has been effectively applied in real-time in vitro tracking of H2O2 effluxes excreted from different live cancer cells and normal cells after being encouraged by stimulation. The results exhibit that molecular-level heteroassembly holds great potential in electrochemical sensors to detect promising biomarkers.


Assuntos
Peróxido de Hidrogênio , Neoplasias , Titânio , Técnicas Eletroquímicas/métodos , Hidróxidos/química , Eletrodos
6.
J Breath Res ; 17(3)2023 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-37040740

RESUMO

PM2.5is a well-known airborne hazard to cause various diseases. Evidence suggests that air pollution exposure contributes to the occurrence of pulmonary nodules. Pulmonary nodules detected on the computed tomography scans can be malignant or progress to malignant during follow-up. But the evidence of the association between PM2.5exposure and pulmonary nodules was limited. To examine potential associations of exposures to PM2.5and its major chemical constituents with the prevalence of pulmonary nodules. A total of 16 865 participants were investigated from eight physical examination centers in China from 2014 to 2017. The daily concentrations of PM2.5and its five components were estimated by high-resolution and high-quality spatiotemporal datasets of ground-level air pollutants in China. The logistic regression and the quantile-based g-computation models were used to assess the single and mixture impact of air pollutant PM2.5and its components on the risk of pulmonary nodules, respectively. Each 1 mg m-3increase in PM2.5(OR 1.011 (95% CI: 1.007-1.014)) was positively associated with pulmonary nodules. Among five PM2.5components, in single-pollutant effect models, every 1µg m-3increase in organic matter (OM), black carbon (BC), and NO3-elevated the risk of pulmonary nodule prevalence by 1.040 (95% CI: 1.025-1.055), 1.314 (95% CI: 1.209-1.407) and 1.021 (95% CI: 1.007-1.035) fold, respectively. In mixture-pollutant effect models, the joint effect of every quintile increase in PM2.5components was 1.076 (95% CI: 1.023-1.133) fold. Notably, NO3-BC and OM contributed higher risks of pulmonary nodules than other PM2.5components. And the NO3-particles were identified to have the highest contribution. The impacts of PM2.5components on pulmonary nodules were consistent across gender and age.These findings provide important evidence for the positive correlation between exposure to PM2.5and pulmonary nodules in China and identify that NO3-particles have the highest contribution to the risk.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Humanos , Material Particulado/efeitos adversos , Prevalência , Testes Respiratórios , Poluição do Ar/efeitos adversos , Poluição do Ar/análise , Poluentes Atmosféricos/efeitos adversos , China/epidemiologia , Exposição Ambiental/efeitos adversos , Exposição Ambiental/análise
7.
Int J Cardiol ; 378: 130-137, 2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-36841290

RESUMO

BACKGROUND: Atrial fibrillation (AF) is the most common type of treated heart arrhythmia contributing to adverse cardiovascular events. The association between short-term air pollution exposure and AF episodes has been recognized. But the evidence of the association between long-term air pollution exposure and AF was limited, especially in developing countries. METHODS: We performed a nationwide cross-sectional study among 1,374,423 individuals aged ≥35 years from 13 health check-up centers. Using logistic regression models, we assessed the association between long-term exposure to single air pollution and AF prevalence, including particulate matter (PM2.5 and PM10), ozone (O3) and PM2.5 compositions, which were estimated by high-resolution and high-quality spatiotemporal datasets of ground-level air pollutants for China. The quantile g-computation model was used to explore the joint effect of all exposures to air pollution and the contribution of an individual component to the mixture. RESULTS: In single-pollutant models, an increase of 10 µg/m3 in PM2.5 (OR 1.031[95%CI 1.010,1.053]) and PM10 (OR = 1.021 [95%CI 1.009,1.033]) was positively associated with AF prevalence. The stratified analyses revealed that these associations were significantly stronger in females, people <65 years old, and those with hypertension and diabetes. In the further exploration of the joint effect of PM2.5 compositions (OR 1.060 [95%CI 1.022,1.101]) per quintile increase in all five PM2.5 components), we found that PM2.5 sulfate contributed the most. CONCLUSIONS: These findings provide important evidence for the positive relationship between long-term exposure to air pollution and AF prevalence in China and identify sulfate particles of PM2.5 as having the highest contribution to the overall mixture effects among all PM2.5 chemical constituents.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Fibrilação Atrial , Feminino , Humanos , Idoso , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/epidemiologia , Fibrilação Atrial/etiologia , Estudos Transversais , Prevalência , Poluição do Ar/efeitos adversos , Poluição do Ar/análise , Poluentes Atmosféricos/efeitos adversos , Poluentes Atmosféricos/análise , Material Particulado/efeitos adversos , Material Particulado/análise , China/epidemiologia , Exposição Ambiental/efeitos adversos , Exposição Ambiental/análise , Dióxido de Nitrogênio/efeitos adversos
8.
Sci Total Environ ; 867: 161472, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-36638985

RESUMO

Previous studies have reported potential adverse effects of exposure to ambient air pollutants on semen quality in infertile men, but studies on the general population have been limited and inconsistent, and the pollutants that play a major role remain unclear. This study aimed to explore the potential association between exposure to six air pollutants (PM2.5, PM10, NO2, SO2, O3 and CO) during different sperm development periods and semen quality among the general population, and to explore the interaction between different air pollutant exposures. We included 1515 semen samples collected from the Human Sperm Bank. We improved individuals' exposure level estimation by combining inverse distance weighting (IDW) interpolation with satellite remote sensing data. Multivariate linear regression models, restricted cubic spline functions and double-pollutant models were used to assess the relationship between exposure to six air pollutants and sperm volume, concentration, total sperm number and sperm motility. A negative association was found between SO2 exposure and progressive motility and total motility during 0-90 lag days and 70-90 lag days, and SO2 exposure during 10-14 lag days adversely affected sperm concentration and total sperm number. Sensitive analyses for qualified sperm donors and the double-pollutant models obtained similar results. Additionally, there were nonlinear relationships between exposure to PM, NO2, O3, CO and a few semen parameters, with NO2 and O3 exposure above the threshold showing negative correlations with total motility and progressive motility, respectively. Our study suggested that SO2 may play a dominant role in the adverse effects of ambient air pollutants on semen quality in the general population by decreasing sperm motility, sperm concentration and total sperm number. Also, even SO2 exposure lower than the recommended standards of the World Health Organization (WHO) could still cause male reproductive toxicity, which deserves attention.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Ambientais , Humanos , Masculino , Poluentes Atmosféricos/toxicidade , Poluentes Atmosféricos/análise , Dióxido de Enxofre/toxicidade , Dióxido de Enxofre/análise , Análise do Sêmen , Poluentes Ambientais/análise , Dióxido de Nitrogênio/toxicidade , Dióxido de Nitrogênio/análise , Poluição do Ar/efeitos adversos , Poluição do Ar/análise , Material Particulado/análise , Sêmen , Motilidade dos Espermatozoides , China/epidemiologia , Exposição Ambiental/análise
9.
Anal Chim Acta ; 1239: 340730, 2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36628773

RESUMO

In this work, we report the development of a new type of highly active and stable Bi-based electrode material, i.e., BiCu metal-organic frames (MOF) derived carbon film (CF) encapsulating BiCu alloy nanoparticles (BiCu-ANPs) for electrochemical sensing. The integration of Bi with Cu to form BiCu-ANPs can improve their electrocatalytic activity as well as the acid resistance. Meanwhile, the carbon film that encapsulates BiCu-ANPs not only guarantees the BiCu-ANPs with high electrical conductivity and fast electrochemical kinetics but also effectively alleviates the volume change during the adsorption and desorption of heavy metal (HM) ions. Therefore, the as-obtained CF encapsulating BiCu-ANPs (BiCu-ANPs@CF) exhibits fully exposed active sites, facile charge transfer, high stability and conductivity, which gives rise to enhanced sensitivity and stability for the electrochemical detection of HM ions. When integrated into a potable electrochemical sensing system for simultaneous detection of Pb2+, Cd2+ and Zn2+, the BiCu-ANPs@CF modified electrode exhibits low detection limit (i.e., 0.081 ppb for Pb2+, 0.95 ppb for Cd2+, 35 ppb for Zn2+), wide detection range (i.e., 0.5-700 ppb for Pb2+, 5-900 ppb for Cd2+, 150-600 ppb for Zn2+) and good anti-interference. Finally, the system has been used for on-site detection of multiplexed HM ions in human biological liquids and environmental water with a good spiked recovery rate, which demanstrates its promise application in the future for on-site monitoring of human health and pollutants in water quality.


Assuntos
Nanopartículas Metálicas , Metais Pesados , Humanos , Carbono , Cádmio/química , Ligas , Chumbo , Metais Pesados/química , Íons
10.
ACS Nano ; 16(12): 21324-21333, 2022 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-36519795

RESUMO

Reservoir computing (RC) is a computational architecture capable of efficiently processing temporal information, which allows low-cost hardware implementation. However, the previously reported memristor-based RC mostly utilized binarized data sets to reduce the difficulty of signal processing of the memristor, which inevitably induces data distortion to a certain extent, leading to poor network computing performance. Here, we report on a RC system in a fully memristive architecture based on solution-processed perovskite memristors. The perovskite memristor exhibits 10000 conductance states with a modulation range of more than 4 orders of magnitude. The obtained tens of thousands of finely spaced conductance states with a near-ideal analog property provide a sufficiently large dynamic range and enough intermediate states, which were further applied as a reservoir to map the feature information on different sequential inputs in an analog way. The computing capability of the image classification task of a Fashion-MNIST data set with a high recognition accuracy of up to 90.1% shows that the excellent analog and short-term properties of our perovskite memristor allow the hardware implementation of neuromorphic computing with a reduced training cost.

11.
Talanta ; 249: 123612, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-35688080

RESUMO

The development of facile, rapid and cost-effective strategies for sensitive detection of cancer biomarkers in human samples is of great significance for early diagnosis of malignant tumors related diseases. In this work, we develop a high-performance electrochemical biosensor based on highly active dual nanozyme amplified system, i.e., ultrathin two-dimension (2D) conductive metal-organic framework (C-MOF) nanosheets (NSs) decorated with high-density ultrafine gold nanoparticles (Au-NPs), and explore its application in sensitive detection of cancer biomarker H2O2 in live cells. The C-MOF NSs {i.e., Cu-HHTP (HHTP = 2,3,6,7,10,11-hexahydroxytriphenylene)-NSs} provide large surface area and abundant active open metal sites (Cu-O4), which could improve the catalytic activity of Cu-HHTP-NSs towards H2O2. Moreover, abundant exposed O atoms also serve as anchor sites for the deposition of high-density ultrafine Au-NPs (∼3 nm) without agglomeration. Owing to the synergistic contributions of high catalytic activity of Cu-HHTP-NSs and Au-NPs as well as their unique structural and electrical properties, the as-prepared nanohybrid modified electrode exhibits good sensing performances to H2O2 with an extremely low detection limit of 5.6 nM (3σ rules) and a high sensitivity of 188.1 µA cm-2 mM-1. Furthermore, the proposed nanozymatic electrochemical biosensor has been applied in real-time tracking H2O2 released from different human colon cells to identify colon cancer cells from normal colon epithelial cell, which demonstrates its great prospect for early diagnosis and management of various cancer diseases.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Estruturas Metalorgânicas , Neoplasias , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Ouro/química , Humanos , Peróxido de Hidrogênio , Limite de Detecção , Nanopartículas Metálicas/química , Neoplasias/diagnóstico
12.
Mater Horiz ; 9(7): 1878-1887, 2022 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-35726680

RESUMO

The floating body effect in Meta-Stable-Dip RAM (MSDRAM) has been broadly employed in implementing single-transistor capacitor-less (1T0C) dynamic random access memory (DRAM) cells to break through the limitation of finite size reduction of peripheral capacitors. However, the majority of them were broadly demonstrated in conventional CMOS technology, while emerging semiconductor systems are rarely explored. Here, we creatively explore exfoliated multilayer tungsten diselenide (WSe2) for the application of 1T0C DRAM, breaking the limitation of channel thickness in the traditional architecture. Through the comparison of the electrical characteristics among three dual-gate transistors with different lengths of top-gate, we demonstrated the essential role of the floating body effect in achieving the function of 1T0C DRAM displaying two distinct states that are differentiated by hole population within the floating body. Moreover, according to the analysis of in situ electrostatic force microscopy (EFM) measurements and theoretical calculation via density functional theory (DFT), the injection of holes through band-to-band (B2B) tunneling can be ascribed to the effectively electrostatic modulation. These consequences prove our innovative concept to achieve the function of 1T0C DRAM through employing the ML WSe2, which is a vital step toward the breakthrough of the inherent limitations of DRAM cells.


Assuntos
Semicondutores
13.
ACS Appl Mater Interfaces ; 14(17): 19480-19490, 2022 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-35446543

RESUMO

The ultrasensitive determination of sulfate reducing bacteria (SRB) is of great significance for their crucial roles in environmental and industrial harms together with the early detection of microbial corrosion. In this work, we report the development of highly efficient electrocatalysts, i.e., Cu2O-CuO extended hexapods (EHPs), which are wrapped on homemade freestanding graphene paper to construct a flexible paper electrode in the electrochemical sensing of the biomarker sulfide for SRB detection. Herein Cu2O-CuO EHPs have been synthesized via a highly controllable and facile approach at room temperature, where the redox centers of copper oxide nanoarchitectures are tuned via facet engineering, and then they are deposited on the graphene paper surface through an electrostatic adsorption to enable homogeneous and highly dense distribution. Owing to the synergistic contribution of high electrocatalytic activity from the Cu mixed oxidation states and abundant catalytically active facets of Cu2O-CuO EHPs and high electrical conductivity of the graphene paper electrode substrate, the resultant nanohybrid paper electrode has exhibited superb electrochemical sensing properties for H2S with a wide linear range up to 352 µM and an extremely low detection limit (LOD) of 0.1 nM with a signal-to-noise ratio of 3 (S/N = 3), as well as high sensitivity, stability, and selectivity. Furthermore, taking advantage of the good biocompatibility and mechanical flexibility, the electrochemical sensing platform based on the proposed electrode has been applied in the sensitive detection of SRB in environmental samples through the sensing of sulfide from SRB, which holds great promise for on-site and online corrosion and environmental monitoring.


Assuntos
Técnicas Biossensoriais , Grafite , Cobre/química , Técnicas Eletroquímicas , Eletrodos , Grafite/química , Oxirredução , Óxidos/química , Sulfetos
14.
Small ; 18(12): e2106253, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35083839

RESUMO

2D materials with intriguing properties have been widely used in optoelectronics. However, electronic devices suffered from structural damage due to the ultrathin materials and uncontrolled defects at interfaces upon metallization, which hindered the development of reliable devices. Here, a damage-free Au/h-BN/Au memristor is reported using a clean, water-assisted metal transfer approach by physically assembling Au electrodes onto the layered h-BN which minimized the structural damage and undesired interfacial defects. The memristors demonstrate significantly improved performance with the coexistence of nonpolar and threshold switching as well as tunable current levels by controlling the compliance current, compared with devices with evaporated contacts. The devices integrated into an array show suppressed sneak path current and can work as both logic gates and latches to implement logic operations allowing in-memory computing. Cross-sectional scanning transmission electron microscopy analysis validates the feasibility of this nondestructive metal integration approach, the crucial role of high-quality atomically sharp interface in resistive switching, and a direct observation of percolation path. The underlying mechanism of boron vacancies-assisted transport is further supported experimentally by conductive atomic force microscopy free from process-induced damage, and theoretically by ab initio simulations.

15.
Mol Ecol Resour ; 21(8): 2689-2705, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33745225

RESUMO

Population genetics relies heavily on simulated data for validation, inference and intuition. In particular, since the evolutionary 'ground truth' for real data is always limited, simulated data are crucial for training supervised machine learning methods. Simulation software can accurately model evolutionary processes but requires many hand-selected input parameters. As a result, simulated data often fail to mirror the properties of real genetic data, which limits the scope of methods that rely on it. Here, we develop a novel approach to estimating parameters in population genetic models that automatically adapts to data from any population. Our method, pg-gan, is based on a generative adversarial network that gradually learns to generate realistic synthetic data. We demonstrate that our method is able to recover input parameters in a simulated isolation-with-migration model. We then apply our method to human data from the 1000 Genomes Project and show that we can accurately recapitulate the features of real data.


Assuntos
Software , Simulação por Computador , Demografia , Humanos
16.
Adv Mater ; 32(52): e2003610, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33165986

RESUMO

The human brain is a sophisticated, high-performance biocomputer that processes multiple complex tasks in parallel with high efficiency and remarkably low power consumption. Scientists have long been pursuing an artificial intelligence (AI) that can rival the human brain. Spiking neural networks based on neuromorphic computing platforms simulate the architecture and information processing of the intelligent brain, providing new insights for building AIs. The rapid development of materials engineering, device physics, chip integration, and neuroscience has led to exciting progress in neuromorphic computing with the goal of overcoming the von Neumann bottleneck. Herein, fundamental knowledge related to the structures and working principles of neurons and synapses of the biological nervous system is reviewed. An overview is then provided on the development of neuromorphic hardware systems, from artificial synapses and neurons to spike-based neuromorphic computing platforms. It is hoped that this review will shed new light on the evolution of brain-like computing.


Assuntos
Engenharia , Redes Neurais de Computação , Neurônios/citologia , Humanos
17.
BMC Gastroenterol ; 20(1): 249, 2020 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-32736604

RESUMO

BACKGROUND: Alpha-fetoprotein (AFP) has been widely used for many years as a serum marker for hepatocellular carcinoma (HCC). However, AFP has been recognized as having poor sensitivity. More and more studies have concluded that circulating microRNAs (miRNAs) might be a promising biomarker that could complement AFP. However, the diagnostic ability of circulating miRNAs has varied among the studies. Therefore, we performed the present meta-analysis to appraise the diagnostic performance of circulating miRNAs as a biomarker for hepatitis B virus-associated HCC (HBV-HCC) patients with low AFP levels. METHODS: We performed a systematic review and meta-analysis of the published literature to assess the diagnostic accuracy of circulating miRNAs in differentiating HBV-HCC patients with low AFP levels from non-HCC controls. RESULTS: Circulating miRNAs showed promising potential in the diagnosis of HBV-HCC patients with low AFP levels. In the low-AFP HBV-HCC patients, the area under the curve (AUC) was 0.88 (95% confidence interval [CI]: 0.84-0.90). The pooled sensitivity and specificity were 0.84 (95% CI: 0.78-0.88) and 0.76 (95% CI: 0.69-0.83), respectively. CONCLUSIONS: The detection of circulating miRNAs provides a valuable method for the diagnosis of HBV-HCC in patients with low AFP levels.


Assuntos
Carcinoma Hepatocelular , MicroRNA Circulante , Neoplasias Hepáticas , MicroRNAs , Biomarcadores Tumorais , Carcinoma Hepatocelular/diagnóstico , Vírus da Hepatite B/genética , Humanos , Neoplasias Hepáticas/diagnóstico , Curva ROC , alfa-Fetoproteínas
18.
Cancer Manag Res ; 12: 3903-3914, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32547226

RESUMO

BACKGROUND: The decline of a long non-coding RNA (lncRNA) DIO3OS was implicated in a plethora of cancers, while the relevance in hepatocellular carcinoma (HCC) has not been mentioned. Accordingly, we set to determine the functional role of DIO3OS and the molecular mechanism in HCC progression. MATERIALS AND METHODS: The differentially expressed lncRNAs, mRNAs, and microRNAs (miRNAs) were obtained through the datasets GSE101728 and GES57555. Afterwards, DIO3OS was enhanced in HCC cells to examine the behavior changes. Subcellular localization of DIO3OS was determined through website prediction and experimental validation. The expression of Hedgehog (Hh) signaling pathway-related genes was detected. The effects of DIO3OS overexpression on tumor growth were evaluated as well. RESULTS: DIO3OS was lower in HCC tissues and cells, while upregulation of DIO3OS repressed malignant biological behavior both in vitro and in vivo. DIO3OS, localized in the cytoplasm, inhibited the occurrence of HCC by disrupting the Hh pathway by sponging miR-328 to mediate Hh interacting protein (Hhip). CONCLUSION: All in all, the obtained data suggested that DIO3OS interacted with Hhip-dependent Hh signaling pathway to inhibit HCC progression through binding to miR-328, which may be a potent therapeutic target for HCC.

19.
Nano Lett ; 20(7): 5562-5569, 2020 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-32579373

RESUMO

Core-shell semiconductor quantum dots (QDs) are one of the biggest nanotechnology successes so far. In particular, type-I QDs with straddling band offset possess the ability to enhance the charge carriers capturing which is useful for memory application. Here, the type-I core-shell QD-based bipolar resistive switching (RS) memory with anomalous multiple SET and RESET processes was demonstrated. The synergy and competition between space charge limited current conduction (arising from charge trapping in potential well of type-I QDs) and electrochemical metallization (ECM, originating from redox reaction of Ag electrode) process were employed for modulating the RS behavior. Through utilizing stochastic RS mechanisms in QD-based devices, four situations of RS behaviors can be classified into three states in Markov chain for implementing the application of a true random number generator. Furthermore, a 6 × 6 cross-bar array was demonstrated to realize the generation of random letters with case distinction.

20.
Cancer Manag Res ; 12: 2353-2364, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32280274

RESUMO

BACKGROUND: Carboxypeptidase X, M14 family member 2 (CPXM2) has been reported to be involved with several human malignancies. However, the impact of CPXM2 on human hepatocellular carcinoma (HCC) tumorigenesis has not been studied. MATERIALS AND METHODS: Using immunohistochemistry, the detailed CPXM2 expression patterns were examined in HCC cell lines and tissues. Additionally, a hepatic stellate cell line overexpressing CPXM2 and an HCC CPXM2-knockdown cell line were established by lipofection of an expression plasmid or short hairpin RNA, respectively. The transfection efficiencies were confirmed by reverse transcription-quantitative PCR, Western blotting and immunofluorescence. Moreover, Western blotting was conducted to determine the phosphorylation levels of the tyrosine kinase 2 (JAK2)/signal transducer and activator of transcription 3 (Stat1) pathway. Furthermore, gp130-specific hairpin RNA was used to knockdown gp130 expression in hepatic stellate cells overexpressing CPXM2. The malignant phenotype of cultured HCC cells was assessed by a Cell Counting Kit-8 (CCK8) assay, plate cloning assay, Matrigel invasion assay and wound-healing assay in vitro. RESULTS: It was demonstrated that CPXM2 was upregulated in HCC, and its upregulation predicted a poor prognosis. Besides, the upregulation of CPXM2 markedly enhanced the metastatic potential of HCC via the gp130/JAK2/Stat1 signaling pathway in vitro. CONCLUSION: In summary, this evidence suggests a positive role for CPXM2 in HCC progression via modulation of the gp130/JAK2/Stat1 signaling pathway in HCC.

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