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1.
J Environ Manage ; 353: 120020, 2024 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-38278115

RESUMEN

Dredged soil and phosphogypsum (PG) are waste materials that must be treated to reduce their negative environmental effects. Guided by the concept of waste treatment, this study proposed the use of PG as a supplementary cementitious material to stabilize waste-dredged soil, and calcium aluminate cement (CAC) was selected to further improve the strength of the cement-treated dredged soil. Several laboratory tests were conducted to investigate the pH, unconfined compressive strength (UCS), and failure strain of the cement-treated soils in different proportions. Microstructural and mineralogical tests were performed to reveal the mechanisms underlying the strength improvement of PG and CAC. The results showed that both PG and CAC enhanced the strength of cement-treated dredged soil. PG provided SO2- 4 to promote the formation of ettringite (aluminum ferrite trisulfate (AFt)), whereas CAC neutralized the acidity of PG and provided reactants to the reaction system, leading to an increase in the pH and strength with an increase in the relative CAC content. Meanwhile, an exponential relationship was obtained between pH and qu. Mineralogical changes demonstrated that the major hydration products of cementitious materials, such as calcium silicate (aluminate) hydrate (C-(A)-S-H), AFt, and calcium aluminate hydrate (C-A-H), enhanced the strength by filling pores between particles and bridging soil particles. However, excess CAC content may not be favorable for the later strength formation, the relative CAC content is recommended to be in the range of 40%-60%. Compared to using sand, the construction of a square kilometer of reclamation consumed 3.5 million tons of PG, and saved 1.54 billion USD by using dredged soil as raw material. Hence, the use of PG to treat dredged soils will have great environmental sustainability, economic benefits, and engineering value.


Asunto(s)
Compuestos de Aluminio , Compuestos de Calcio , Fósforo , Suelo , Residuos Sólidos , Sulfato de Calcio
2.
J Phys Condens Matter ; 35(35)2023 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-37230082

RESUMEN

Due to the shrinking in size of nonvolatile memory devices, the two-dimensional ferroelectric van der Waals (vdW) heterostructures have received huge attention. However, it is still difficult to maintain the out-of-plane (OOP) ferroelectricity. In this work, we have theoretically investigated the relationship between the ferroelectricity and the strain of bulk and few-layer SnTe by first-principles calculations. The results indicate that theα-SnTe can exist stably within the strain between -6% and 6%, and the complete OOP polarization occurs within the strain between -4% and -2%. Unfortunately, the OOP polarization disappears while the bulkα-SnTe is thinned to a few layers. However, the complete OOP polarization recurs in monolayer SnTe/PbSe vdW heterostructures, which is due to the strong interface coupling. Our findings provide an effective way to enhance ferroelectric performance, which is beneficial for the design of ultra-thin ferroelectric devices.

3.
Sensors (Basel) ; 23(2)2023 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-36679753

RESUMEN

A noncontact ECG is applicable to wearable bioelectricity acquisition because it can provide more comfort to the patient for long-term monitoring. However, the motion artifact is a significant source of noise in an ECG recording. Adaptive noise reduction is highly effective in suppressing motion artifact, usually through the use of external sensors, thus increasing the design complexity and cost. In this paper, a novel ECG electrode structure is designed to collect ECG data and reference data simultaneously. Combined with the adaptive filter, it effectively suppresses the motion artifact in the ECG acquisition. This method adds one more signal acquisition channel based on the single-channel ECG acquisition system to acquire the reference signal without introducing other sensors. Firstly, the design of the novel ECG electrode structure is introduced based on the principle of noise reduction. Secondly, a multichannel signal acquisition circuit system and ECG electrodes are implemented. Finally, experiments under normal walking conditions are carried out, and the performance is verified by the experiment results, which shows that the proposed design effectively suppresses motion artifacts and maintains the stability of the signal quality during the noncontact ECG acquisition. The signal-to-noise ratio of the ECG signal after noise reduction is 14 dB higher than that of the original ECG signal with the motion artifact.


Asunto(s)
Artefactos , Procesamiento de Señales Asistido por Computador , Humanos , Algoritmos , Movimiento (Física) , Electrodos , Electrocardiografía/métodos
4.
Artículo en Inglés | MEDLINE | ID: mdl-36429997

RESUMEN

This study explores how the services provided by different types of Chinese communities varied in their impact on the social involvement of residents during the COVID-19 pandemic. The literature revealed problems caused by travel restrictions, including using oversimplified measures for grassroots governance, which might result in decreased residents' social involvement during COVID-19. We argue that the services provided by "smart communities" in China not only adhered to the COVID-19 pandemic governance, but also promoted the social involvement of residents. Using a case study approach of the smart community Fang Xing and the traditional community Qili Tang, both of which are located in China, this article compared the traditional and smart community services based on 122 interviews with residents and frontline community staff members. The findings suggest that while the traditional community decreased the residents' social involvement by restricting certain services during the pandemic, the smart community was able to apply COVID-19 governance measures, considerably increasing the residents' social involvement. It offered an attractive option for residents to act as community service managers, and it prepared them for local-level pandemic governance. This study provides an understanding of the relationship between the community services and the residents' social involvement in terms of the community services. The smart community model can act as a reference for international community development during pandemic governance.


Asunto(s)
COVID-19 , Humanos , COVID-19/epidemiología , Pandemias , China/epidemiología , Bienestar Social
5.
Pulm Circ ; 12(3): e12138, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-36186720

RESUMEN

Qingke Pingchuan granules (QKPCG), a patented traditional Chinese medicine, clinically, are recommended for acute tracheobronchitis, cough, community-acquired pneumonia, and other respiratory diseases. However, its potential protective effect and mechanism of action in acute lung injury (ALI) have not been explored. We aimed to explore the mechanisms underlying the protective role of QKPCG in ALI. The therapeutic efficacy of QKPCG was investigated in a lipopolysaccharide (LPS)-induced ALI mouse model. Mice were divided into three groups, namely, the Control, LPS, and LPS + QKPCG groups. Mice in the LPS + QKPCG group were administered QKPCG intragastrically as a treatment once a day for a total of three days. QKPCG effectively increased survival and reduced lung injury in treated mice. It significantly reduced the LPS-induced expression of interleukin (IL)-6, tumor necrosis factor-α (TNF-α), IL-1α, and IL-1ß. RNA-sequencing followed by real-time quantitative polymerase chain reaction validation suggested a critical role of the secretoglobin family 1A member 1 (Scgb1a1) gene in mediating the protective effect of QKPCG. Further, QKPCG reversed the LPS-induced downregulation of the Clara cell 10 kDa protein (CC10), a pulmonary surfactant protein encoded by Scgb1a1, which is mainly secreted by club cells in the lungs. Exogenous supplementation of CC10 alleviated LPS-induced ALI. Hematoxylin and eosin staining and enzyme-linked immunosorbent assay results further confirmed the anti-inflammatory properties of CC10, which were suggested as mediated via the inhibition of NFκB phosphorylation. In summary, our study provides evidence of the beneficial role of QKPCG in alleviating lung injury, mediated via the decreased disruption of club cells and higher expression of CC10, which leads to NFκB pathway inhibition.

6.
ACS Omega ; 7(20): 17075-17082, 2022 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-35647421

RESUMEN

Monoclinic phase bismuth vanadate (BiVO4) is one of the most promising photoelectrochemical materials used in water-splitting photoelectrochemical cells. It could be even better if its band gap and charge transport characteristics were optimized. Although codoping of BiVO4 has proven to be an effective strategy, its effects are remarkably poorly understood. Using the Heyd-Scuseria-Ernzerhof (HSE) hybrid functional, we estimate the formation energy, electronic properties, and photocatalytic activities of F and Mo codoped BiVO4. We find that Mo atoms prefer to replace V atoms, whereas F atoms prefer to replace O atoms (FOMoV-doped BiVO4) under oxygen-poor conditions according to calculated formation energies. BiVO4 doped with FOMoV is found to be shallow-level doped, occurring with some continuum states above the conduction band edge, which is advantageous for photochemical catalysis. Moreover, FOMoV-doped BiVO4 shows absorption stronger than that of pure BiVO4 in the visible spectrum. Based on the band-edge calculation, BiVO4 doped with FOMoV still retains a high oxidizing capacity. It has been shown that FOMoV-doped BiVO4 exhibits a very high photocatalytic activity under visible light.

7.
Comput Intell Neurosci ; 2022: 2743878, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35619760

RESUMEN

Mesenchymal stem cells (MSCs) have promising potential in the treatment of various diseases, such as the therapeutic effect of bone marrow-derived MSCs for phosgene-induced acute lung injury (P-ALI). However, MSC-related therapeutics are limited due to poor cell survival, requiring appropriate MSC delivery systems to maximise therapeutic capacity. Biomaterial RGD-hydrogel is a potential cell delivery vehicle as it can mimic the natural extracellular matrix and provide cell adhesion support. The application of RGD-hydrogel in the MSC treatment of respiratory diseases is scarce. This study reports that RGD-hydrogel has good biocompatibility and can increase the secretion of Angiopoietin-1, hepatocyte growth factor, epidermal growth factor, vascular endothelial cell growth factor, and interleukin-10 in vitro MSCs. The hydrogel-encapsulated MSCs could further alleviate P-ALI and show better cell survival in vivo. Overall, RGD-hydrogel could improve the MSC treatment of P-ALI by modulating cell survival and reparative activities. It is exciting to see more and more ways to unlock the therapeutic potential of MSCs.


Asunto(s)
Lesión Pulmonar Aguda , Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas , Fosgeno , Lesión Pulmonar Aguda/inducido químicamente , Lesión Pulmonar Aguda/metabolismo , Lesión Pulmonar Aguda/terapia , Animales , Médula Ósea/metabolismo , Hidrogeles/efectos adversos , Hidrogeles/metabolismo , Células Madre Mesenquimatosas/metabolismo , Oligopéptidos/efectos adversos , Oligopéptidos/metabolismo , Fosgeno/metabolismo , Fosgeno/toxicidad , Ratas
8.
Nanotechnology ; 32(30)2021 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-33857932

RESUMEN

Afterγ-ray irradiation treatment, a monolayer tungsten diselenide could be transitioned into an n-doped semiconductor due to the anion vacancies created by the radiation. Transmission electron microscope studies showed clear chemical modulation with atomically sharp interface. Change in the lattice vibrational modes induced by passivation of oxygen is captured by Raman spectroscopy. The frequency shifts in both in-plane and out-of-plane modes are dependent linearly on the oxidation content. We observe a negative trion, which is a neutral exciton bound with an electron, in the photoluminescence spectra. The binding energy of this trion is estimated to be ∼90 meV, making it a tightly bound exciton. The first-principles calculation suggests that an increase in the anion vacancy population is generally accompanied by a transition from a direct gap material to an indirect one. This opens up a new venue to engineer the electronic properties of transition metal dichalcogenides by using irradiation.

9.
Opt Express ; 29(4): 5367-5383, 2021 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-33726074

RESUMEN

We examine the effect of cavity field fluctuations on Kerr nonlinearity in an atom-assisted optomechanical system. It is found that a new self-Kerr (SK) nonlinearity term, which can greatly surpass that of a classical Λ type atomic system when the hybrid system has numerous atoms, is generated based on cavity field fluctuations by atom-cavity interactions. A strong photon-phonon cross-Kerr (CK) nonlinearity is also produced based on cavity field fluctuations. These nonlinearity features can be modified by atom-cavity and optomechanical interactions. This work may provide a new method to enhance the SK nonlinearity and generate the photon-phonon CK nonlinearity.

10.
Phys Chem Chem Phys ; 22(43): 25297-25305, 2020 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-33140077

RESUMEN

In this article, we report a periodic density functional theory (DFT) investigation on the formation of the native defects and cerium doping in monoclinic BiVO4 (m-BiVO4) and their effect on the electronic structures, using the Perdew-Burke-Ernzerhof functionals corrected for on-site Coulombic interactions (PBE+U). From the point defect formation energies and transition levels, the Bivac (Bi vacancy), Vvac (V vacancy), Oint (O interstitial) and CeV (Ce doping on V site) defects in m-BiVO4 are identified as shallow acceptors. For Ce doping in m-BiVO4, the substitution of Bi by Ce is energetically favorable in the single positively charged state (Ce) under Bi/V-poor conditions, while the substitution of V by Ce is in the single negatively charged state (Ce) under O-rich conditions. The calculated electronic structures suggest that Ce degrades the activity by an unoccupied deep level in the gap region, mainly composed of Ce 4f orbitals, which makes this defect as the photogenerated electron-hole recombination center, in good agreement with the experimental results. For Ce, no localized state exists within the calculated band gap. Its formation energy is sensitive to the chemical potentials and Fermi energy, suggesting that the Bi/V-poor and O-rich conditions are desirable to eliminate the deep-level states and improve photocatalysis. Our results provide insights into enhancing the photocatalytic activity of m-BiVO4 for energy and environmental applications through the rational design of defect-controlled synthesis conditions.

11.
Clinics (Sao Paulo) ; 75: e1801, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33084768

RESUMEN

Interleukin-6 (IL-6) plays a crucial role in systemic autoimmunity and pathologic inflammation. Numerous studies have explored serum IL-6 levels in systemic lupus erythematosus (SLE) and their correlation with disease activity. Here, we performed a meta-analysis to quantitatively assess the correlation between the serum IL-6 levels and SLE activity. The PubMed and EMBASE databases were thoroughly searched for relevant studies up to September 2019. Standardized mean differences (SMDs) with 95% confidence intervals (95% CIs) were used to describe the differences between serum IL-6 levels in SLE patients and healthy controls and between those in active SLE patients and inactive SLE patients. The correlation between the serum IL-6 levels and disease activity was evaluated using Fisher's z values. A total of 24 studies involving 1817 SLE patients and 874 healthy controls were included in this meta-analysis. Serum IL-6 levels were significantly higher in SLE patients than in the healthy controls (pooled SMD: 2.12, 95% CI: 1.21-3.03, Active SLE patients had higher serum IL-6 levels than inactive SLE patients (pooled SMD: 2.12, 95% CI: 1.21-3.03). Furthermore, the pooled Fisher's z values (pooled Fisher's z=0.36, 95% CI: 0.26-0.46, p<0.01) showed that there was a positive correlation between the serum IL-6 levels and SLE activity. This study suggested that serum IL-6 levels were higher in patients with SLE than in healthy controls, and they were positively correlated with disease activity when Systemic Lupus Erythematosus Disease Activity Index>4 was defined as active SLE. More homogeneous studies with large sample sizes are warranted to confirm our findings due to several limitations in our meta-analysis.


Asunto(s)
Interleucina-6 , Lupus Eritematoso Sistémico , Humanos
12.
Clinics ; 75: e1801, 2020. tab, graf
Artículo en Inglés | LILACS | ID: biblio-1133464

RESUMEN

Interleukin-6 (IL-6) plays a crucial role in systemic autoimmunity and pathologic inflammation. Numerous studies have explored serum IL-6 levels in systemic lupus erythematosus (SLE) and their correlation with disease activity. Here, we performed a meta-analysis to quantitatively assess the correlation between the serum IL-6 levels and SLE activity. The PubMed and EMBASE databases were thoroughly searched for relevant studies up to September 2019. Standardized mean differences (SMDs) with 95% confidence intervals (95% CIs) were used to describe the differences between serum IL-6 levels in SLE patients and healthy controls and between those in active SLE patients and inactive SLE patients. The correlation between the serum IL-6 levels and disease activity was evaluated using Fisher's z values. A total of 24 studies involving 1817 SLE patients and 874 healthy controls were included in this meta-analysis. Serum IL-6 levels were significantly higher in SLE patients than in the healthy controls (pooled SMD: 2.12, 95% CI: 1.21-3.03, Active SLE patients had higher serum IL-6 levels than inactive SLE patients (pooled SMD: 2.12, 95% CI: 1.21-3.03). Furthermore, the pooled Fisher's z values (pooled Fisher's z=0.36, 95% CI: 0.26-0.46, p<0.01) showed that there was a positive correlation between the serum IL-6 levels and SLE activity. This study suggested that serum IL-6 levels were higher in patients with SLE than in healthy controls, and they were positively correlated with disease activity when Systemic Lupus Erythematosus Disease Activity Index>4 was defined as active SLE. More homogeneous studies with large sample sizes are warranted to confirm our findings due to several limitations in our meta-analysis.


Asunto(s)
Humanos , Interleucina-6 , Lupus Eritematoso Sistémico
13.
Phys Chem Chem Phys ; 21(18): 9310-9316, 2019 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-30993296

RESUMEN

Realizing topological Dirac states in two-dimensional (2D) magnetic materials is particularly important to spintronics. Here, we propose that such states can be obtained in a transition-metal (Hf) monolayer grown on a 2D substrate with hexagonal hollow geometry (graphyne). We find that the significant orbital hybridizations between Hf and C atoms can induce sizable magnetism and bring three Dirac cones at/around each high-symmetry K(K') point in the Brillouin zone. One Dirac cone is formed by pure spin-up electrons from the dz2 orbital of Hf, and the remaining two are formed by crossover between spin-up electrons from the dz2 orbital and spin-down electrons from the hybridization of the dxy/x2-y2 orbitals of Hf atoms and the pz orbital of C atoms. We also find that the spin-orbit coupling effect can open sizable band gaps for the Dirac cones. The Berry curvature calculations further show the nontrivial topological nature of the system with a negative Chern number C = -3, which is mainly attributed to the Dirac states. Molecular dynamics simulations confirm the system's thermodynamic stability approaching room temperature. The results provide a new avenue for realizing the high-temperature quantum anomalous Hall effect based on 2D transition-metals.

14.
J Phys Condens Matter ; 30(33): 33LT01, 2018 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-29989566

RESUMEN

Based on the non-equilibrium Green's function method, the conductance anisotropy of black phosphorene has been studied under chemical potential and/or external electric field. The direction and magnitude of the conductance anisotropy strongly depend on the chemical potential, which are in good agreement with experimental observations. Furthermore, the magnitude of conductance anisotropy can be largely modulated by external electric field, which is one order of magnitude larger than previously reported. The directions of the maximum and minimum conductance can be reversed by external electric field, which shows that the former jumps from 24° to 90° and the latter jumps from 90° to 0° respectively. The results are fundamentally interesting and technologically promising in nano-electronics.

15.
J Phys Condens Matter ; 28(14): 145003, 2016 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-26965319

RESUMEN

We have performed nonequilibrium molecular dynamics calculations on the length (L) dependence of thermal conductivity (Κ) of silicene both supported on and sandwiched between the smooth surfaces, i.e. h-BN, at room temperature. We find that Κ of silicene follows a power law Κ [proportional] L(ß), with ß increasing from about 0.3-0.4 under the effect of interface coupling, showing an enhancement of the ballistic thermal transport of silicene. We also find that ß can be further increased to about 0.6 by increasing the interface coupling strength for the silicene sandwiched between h-BN. The increase of ß for the supported case is found to come from the variation of the flexural acoustic (ZA) phonon mode and the first optical phonon mode induced by the substrate, whereas the unusual increase of ß for the sandwiched case is attributed to the increment of velocities of all three acoustic phonon modes. These findings provide an interesting route for manipulating the ballistic energy flow in nanomaterials.

16.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 33(2): 303-7, 2016 Apr.
Artículo en Chino | MEDLINE | ID: mdl-29708664

RESUMEN

This paper presents a kind of automatic segmentation method for white blood cell based on HSI corrected space information fusion.Firstly,the original cell image is transformed to HSI colour space conversion.Because the transformation formulas of H component piecewise function was discontinuous,the uniformity of uniform visual cytoplasm area in the original image was lead to become lower in this channel.We then modified formulas,and then fetched information of nucleus,cytoplasm,red blood cells and background region according to distribution characteristics of the H,S and I-channel,using the theory and method of information fusion to build fusion imageⅠand fusion imageⅡ,which only contained cytoplasm and a small amount of interference,and fetched nucleus and cytoplasm respectively.Finally,we marked the nucleus and cytoplasm region and obtained the final result of segmentation.The simulation results showed that the new algorithm of image segmentation for white blood cell had high accuracy,robustness and universality.


Asunto(s)
Algoritmos , Color , Procesamiento de Imagen Asistido por Computador , Leucocitos/citología , Núcleo Celular , Citoplasma , Eritrocitos , Humanos , Manejo de Especímenes
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