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1.
Discov Nano ; 18(1): 121, 2023 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-37773549

RESUMO

In this paper, we present a new novel simple iTFET with overlapping gate on source-contact (SGO), Drain Schottky Contact, and intrinsic SiGe pocket (Pocket-SGO iTFET). The aim is to achieve steep subthreshold swing (S.S) and high ION current. By optimizing the gate and source-contact overlap, the tunneling efficiency is significantly enhanced, while the ambipolar effect is suppressed. Additionally, using a Schottky contact at the drain/source, instead of ion implantation drain/source, reduces leakage current and thermal budget. Moreover, the tunneling region is replaced by an intrinsic SiGe pocket posing a narrower bandgap, which increases the probability of band-to-band tunneling and enhances the ION current. Our simulations are based on the feasibility of the actual process, thorough Sentaurus TCAD simulations demonstrate that the Pocket-SGO iTFET exhibits an average and minimum subthreshold swing of S.Savg = 16.2 mV/Dec and S.Smin = 4.62 mV/Dec, respectively. At VD = 0.2 V, the ION current is 1.81 [Formula: see text] 10-6 A/µm, and the ION/IOFF ratio is 1.34 [Formula: see text] 109. The Pocket-SGO iTFET design shows great potential for ultra-low-power devices that are required for the Internet of Things (IoT) and AI applications.

2.
Materials (Basel) ; 15(20)2022 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-36295143

RESUMO

The involvement of magnesium matrix composite enhanced by metal particles, the development of low lattice mismatch interface, and the refining of particle size are all of great significance in improving strengthening efficiency. In this work, nano-crystalline Ti/Mg-9Al-Zn-0.3Mn composites were prepared by mechanical milling. The microstructure was characterized and the mechanical property was measured. After mechanical milling, the grain of the Mg matrix was refined to ~72 nm. Ti particles were smashed to submicron scale, and dispersed in the Mg matrix. In total, 68% of Ti particles were nano-scale and the average particle size was 133 nm. A nano-scale Mg17Al12 precipitate was found and the average particle size was approximately 44 nm. Meanwhile, coherent interfaces of Ti/Mg and Mg17Al12/Mg were observed, and it was found that the (101)Mg plane and (100)Ti plane inclined 12° and [044]Mg17Al12 was parallel to [010]Mg. The hardness of the milled Ti/Mg-9Al-Zn-0.3Mn composite was 1.98 GPa, 247% higher than the initial alloy. Milled Mg-9Al-Zn-0.3Mn alloy under the same preparation processing was used as a comparison, and the value of hardness was 1.53 GPa. Tiny Ti particles displayed excellent strengthening efficiency. Strengthening mechanisms of the milled Ti/Mg-9Al-Zn-0.3Mn composite were analyzed and the main strengthening mechanisms included the strengthening of grain boundary strengthening, Orowan strengthening, dislocation strengthening, solid solution strengthening and load-bearing strengthening, which accounted for 56.3%, 18.2%, 17.4%, 4.7% and 3.5%, respectively.

3.
Environ Sci Pollut Res Int ; 29(42): 63423-63443, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35460008

RESUMO

Industrial upgrading is the key to promoting green economic efficiency. Coordination between environmental regulations and industrial structure can lead to sustainable economic growth. However, insufficient attention has been paid to the mechanism by which environmental regulation (ER) promote green economic efficiency (GEE) under the mediating role of industrial structure optimization. Using robust and comprehensive measures of green economic efficiency, we assess how various environmental regulations affect green economic efficiency as well as the intermediate effect of industrial structure of a certain province with provincial panel data during the period 2003-2017. The results of dynamic panel two-step system generalized method of moments (GMM) confirm the heterogeneous effects of the three types of ER, namely control-and-command regulation, market-based regulation, and voluntary regulation on GEE in China. The spatial analysis demonstrates that control-and-command and voluntary regulations significantly accelerate GEE in inland provinces, while they have insignificant effect in coastal provinces. Based on the mediating analysis, we find that market-based regulation is conducive to GEE through both advanced and rationalized industrial structure, whereas control-and-command regulation improves GEE through advanced industrial structure only. The voluntary-based regulation on one hand stimulates GEE through advanced industrial structure, but on other hand impedes it through rationalized industrial structure. The results could provide critical insights and a theoretical basis for policy makers in reasonable optimization of industrial structure and guaranteeing green economic efficiency.


Assuntos
Desenvolvimento Econômico , Indústrias , China , Eficiência
4.
J Inorg Biochem ; 226: 111626, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34655961

RESUMO

The selective visualization of H2S in mitochondria is still a challenge, but it correlates closely with mitochondrial damage and some related diseases. In this work, a cyclometalated iridium complex Ir-DNB, [Ir(ppy)2(N^N)](PF6) (ppy = 2-phenylpyridine, N^N = (4'-methyl-[2,2'-bipyridin]-4-yl)methyl 2-((2,4-dinitrophenyl) thio)benzoate) has been explored for the detection of mitochondrial H2S. Adding H2S to a solution of complex Ir-DNB results in a clearly luminescence enhancement, and displays high selectivity and sensitivity. Moreover, this complex displays negligible toxicity and good mitochondrial localization to HeLa cells, and has also been successfully used for endogenous and exogenous H2S imaging in vitro and in vivo.


Assuntos
Complexos de Coordenação/química , Corantes Fluorescentes/química , Sulfeto de Hidrogênio/metabolismo , Irídio/química , Mitocôndrias/metabolismo , Animais , Feminino , Células HeLa , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Microscopia de Fluorescência
5.
Materials (Basel) ; 14(22)2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34832291

RESUMO

The appearance of the ε phase during the welding process can severely weaken the welding strength of dissimilar metals of Mg-Zn-Al alloy systems. An understanding of the accurate phase diagram, especially the equilibrium phase relation around the ε phase, is thus of particular importance. However, the phase interrelation near the ε-Mg23(Al, Zn)30 phase has not yet been fully studied. In this work, the local phase diagrams of the ε phase and its surrounding phases in the Mg-Zn-Al system are systematically determined by experimental investigation and thermodynamic verification. Five Mg-Zn-Al alloys and one diffusion couple were fabricated and analyzed to get accurate phase constituents and relationships adjacent to ε phase. The current experimental data obtained from Scanning Electron Microscope (SEM), X-ray diffraction (XRD), Differential Scanning Calorimetry (DSC), and Electron Probe Micro Analysis (EPMA) were further compared with the thermodynamically computed phase relations around ε phase for verification, showing good agreements. Several important conclusions are drawn based on current experimental work, which can provide supporting information for the follow-up studies on ε phase in the Mg-Zn-Al alloy systems.

6.
Materials (Basel) ; 14(13)2021 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-34209855

RESUMO

Composition-dependent interdiffusion coefficients are key parameters in many physical processes. However, finding such coefficients for a system with few components is challenging due to the underdetermination of the governing diffusion equations, the lack of data in practice, and the unknown parametric form of the interdiffusion coefficients. In this work, we propose InfPolyn, Infinite Polynomial, a novel statistical framework to characterize the component-dependent interdiffusion coefficients. Our model is a generalization of the commonly used polynomial fitting method with extended model capacity and flexibility and it is combined with the numerical inversion-based Boltzmann-Matano method for the interdiffusion coefficient estimations. We assess InfPolyn on ternary and quaternary systems with predefined polynomial, exponential, and sinusoidal interdiffusion coefficients. The experiments show that InfPolyn outperforms the competitors, the SOTA numerical inversion-based Boltzmann-Matano methods, with a large margin in terms of relative error (10× more accurate). Its performance is also consistent and stable, whereas the number of samples required remains small.

7.
Ying Yong Sheng Tai Xue Bao ; 32(4): 1518-1530, 2021 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-33899421

RESUMO

The evaluation of ecosystem service value is one of the important steps to improve ecosystem accounting methods and the existing accounting systems, and also one of the key techniques to accelerate the reform of ecological civilization system and to build a beautiful China. However, few literature have systematically distinguished the valuation methods of ecosystem services based on the purpose of valuation, which may lead to overestimation of ecosystem services value from the demand side and inconsistent measurement results among different departments. Based on the purpose of ecosystem accounting, we reviewed the valuation methods of ecosystem services. We started from the connotation and value of ecosystem services, illustrated the classification methods of ecosystem ser-vice value and concluded the approaches of ecosystem service economic units, with the aim to identify the extent to which ecosystem services were involved in system of national accounts (SNA). Then, we systematically sorted out the connotation, applicable scope and data demand of current ecosystem service valuation methods. From the perspective of ecosystem accounting, we discussed the valuation methods applicable to various types of ecosystem services. Finally, we analyzed the deficiency of the current relevant research and proposed some suggestions for the future research.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , China
8.
Environ Toxicol ; 32(9): 2203-2211, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28568508

RESUMO

OBJECTIVES: The intense commercial application of silver nanoparticles (AgNPs) has been raising concerns about their potential adverse health effects to human. This study aimed to explore the potency of AgNPs to induce GADD45α gene, an important stress sensor, and its relationships with the cytotoxicity and genotoxicity elicited by AgNPs. METHODS: Two established HepG2 and A549 cell lines containing the GADD45α promoter-driven luciferase reporter were treated with increasing concentrations of AgNPs for 48 hours. After the treatment, transcriptional activation of GADD45α indicated by luciferase activity, cell viability, cell cycle arrest, and levels of genotoxicity were determined. The uptake and intracellular localization of AgNPs, cellular Ag doses as well as Ag+ release were also detected. RESULTS: AgNPs could activate GADD45α gene at the transcriptional level as demonstrated by the dose-dependent increases in luciferase activity in both the reporter cells. The relative luciferase activity was greater than 12× the control level in HepG2-luciferase cells at the highest concentration tested where the cell viability decreased to 17.0% of the control. These results was generally in accordance with the positive responses in cytotoxicity, cell cycle arrest of Sub G1 and G2/M phase, Olive tail moment, micronuclei frequency, and the cellular Ag content. CONCLUSIONS: The cytotoxicity and genotoxicity of AgNPs seems to occur mainly via particles uptake and the subsequent liberation of ions inside the cells. And furthermore, the GADD45α promoter-driven luciferase reporter cells, especially the HepG2-luciferase cells, could provide a new and valuable tool for predicting nanomaterials genotoxicity in humans.


Assuntos
Proteínas de Ciclo Celular/genética , Luciferases/genética , Nanopartículas Metálicas/toxicidade , Proteínas Nucleares/genética , Prata , Células A549 , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Dano ao DNA , Genes Reporter , Células Hep G2 , Humanos , Regiões Promotoras Genéticas , Ativação Transcricional
9.
Toxicol Appl Pharmacol ; 304: 9-17, 2016 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-27211842

RESUMO

The exponential increase in the total number of engineered nanoparticles in consumer products requires novel tools for rapid and cost-effective toxicology screening. In order to assess the oxidative damage induced by nanoparticles, toxicity test systems based on a human HSPA1A promoter-driven luciferase reporter in HepG2, LO2, A549, and HBE cells were established. After treated with heat shock and a group of silver nanoparticles (AgNPs) with different primary particle sizes, the cell viability, oxidative damage, and luciferase activity were determined. The time-dependent Ag(+) ions release from AgNPs in cell medium was also evaluated. Our results showed that heat shock produced a strong time-dependent induction of relative luciferase activity in the four luciferase reporter cells. Surprisingly, at 4h of recovery, the relative luciferase activity was >98× the control level in HepG2-luciferase cells. Exposure to different sizes of AgNPs resulted in activation of the HSPA1A promoter in a dose-dependent manner, even at low cytotoxic or non-cytotoxic doses. The smaller (5nm) AgNPs were more potent in luciferase induction than the larger (50 and 75nm) AgNPs. These results were generally in accordance with the oxidative damage indicated by malondialdehyde concentration, reactive oxygen species induction and glutathione depletion, and Ag(+) ions release in cell medium. Compared with the other three luciferase reporter cells, the luciferase signal in HepG2-luciferase cells is obviously more sensitive and stable. We conclude that the luciferase reporter cells, especially the HepG2-luciferase cells, could provide a valuable tool for rapid screening of the oxidative damage induced by AgNPs.


Assuntos
Proteínas de Choque Térmico HSP70/biossíntese , Nanopartículas Metálicas/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Prata/toxicidade , Células A549 , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Genes Reporter/efeitos dos fármacos , Glutationa/metabolismo , Proteínas de Choque Térmico HSP70/efeitos dos fármacos , Células Hep G2 , Humanos , Luciferases/efeitos dos fármacos , Malondialdeído/metabolismo , Nanopartículas Metálicas/administração & dosagem , Nanopartículas Metálicas/química , Tamanho da Partícula , Regiões Promotoras Genéticas/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Testes de Toxicidade
10.
Toxicol Res (Camb) ; 5(5): 1298-1305, 2016 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-30090433

RESUMO

The use of silver nanoparticles (AgNPs) in consumer products and medical applications is growing rapidly owing to their noted antimicrobial properties. As a consequence, a rapid and reliable toxicology test that allows multiple nanosilver screening in a stress responsive pathway-based assay is needed to ensure consumer safety. Here, novel HSPA1A promoter-driven luciferase reporter gene assays based on two cell models widely used in toxicology testing, HepG2 and A549 cell lines, were developed to analyze the oxidative stress elicited by AgNPs. After AgNP exposure, the luciferase activity, cell viability, and oxidative damage in HepG2- and A549-luciferase cells were determined. The uptake and intracellular localization of AgNPs were measured by transmission electron microscopy. The cellular AgNPs were determined by inductively coupled plasma mass spectrometry. Our results showed that both reporter cells were able to take up nanoparticles and furthermore, exposure to AgNPs resulted in an obviously dose-dependent increase in transcriptional activation of the HSPA1A promoter indicated by luciferase activity. Surprisingly, luciferase activity was greater than 200× the control level in HepG2-luciferase reporter cells treated with 50 µg mL-1 AgNPs. These results were in line with the positive responses in cytotoxicity, intracellular reactive oxygen species induction, glutathione depletion, malondialdehyde concentration, and the cellular silver content. Compared with the A549-luciferase cells, the luciferase signal in the metabolic competent HepG2-luciferase cells is obviously more sensitive and stable. We conclude that these two reporter gene cell systems, especially the HepG2-luciferase cells, demonstrated their utilities in predictive screening of the oxidative stress elicited by nanosilver.

11.
Zhong Yao Cai ; 33(11): 1795-8, 2010 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-21434445

RESUMO

OBJECTIVE: To study the industrialized extraction technology and the function of hyperlipidemic regulating of Laminaria japonica polysaccharides. METHODS: With the orthogonal design L9 (3(4)), different influential elements of the industrialized extraction technology of Laminaria japonica polysaccharides were investigated. Mice treated with different doses of polysaccharides were applied to investigate its-function of hyperlipidemic regulating for 15 days. RESULTS: 5% Na2CO3, 3 hours and 80 degrees C was the best extraction condition, and the extraction rate was 2.13%. Different groups of polysaccharides with different levels of purity and dose lowered the TG, TC level of the mice in various degree. CONCLUSION: Laminaria japonica polysaccharides have obvious effect on hyperlipidemic regulating.


Assuntos
Hiperlipidemias/tratamento farmacológico , Hipolipemiantes/farmacologia , Laminaria/química , Polissacarídeos/isolamento & purificação , Polissacarídeos/farmacologia , Tecnologia Farmacêutica/métodos , Animais , Colesterol/sangue , Modelos Animais de Doenças , Medicamentos de Ervas Chinesas/isolamento & purificação , Medicamentos de Ervas Chinesas/farmacologia , Feminino , Hiperlipidemias/sangue , Hipolipemiantes/isolamento & purificação , Masculino , Camundongos , Polissacarídeos/administração & dosagem , Temperatura , Fatores de Tempo , Triglicerídeos/sangue
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