Greenhouse soils and arable (wheat field) soil samples were collected to identify the effects of greenhouse cultivation on the accumulation of six heavy metals (Cd, Cu, Zn, Pb, Cr, and Ni) and to ...evaluate the likely sources responsible for heavy metal accumulation in the irrigated desert soils of Wuwei District, China. The results indicated that the mean concentrations of Cd, Cu, Zn, Pb, Cr, and Ni were 0.421, 33.85, 85.31, 20.76, 53.12, and 28.59 mg kg⁻¹, respectively. The concentrations of Cd, Cu, and Zn in greenhouse soils were 60, 23, and 14 % higher than those in arable soils and 263, 40, and 25 % higher than background concentrations of natural soils in the study area, respectively. These results indicated that Cd, Cu, and Zn accumulation occurred in the greenhouse soils, and Cd was the most problematically accumulated heavy metal, followed by Cu and Zn. There was a significant positive correlation between the concentrations of Cd, Cu, and Zn in greenhouse soils and the number of years under cultivation (P < 0.05). Greenhouse cultivation had little impact on the accumulation of Cr, Ni, or Pb. Correlation analysis and principal component analysis suggested that the accumulation of Cd, Cu, and Zn in greenhouse soils resulted mainly from fertilizer applications. Our results indicated that the excessive and long-term use of fertilizers and livestock manures with high heavy metal levels leads to the accumulation of heavy metals in soils. Therefore, rational fertilization programs and reductions in the concentrations of heavy metals in both fertilizers and manure must be recommended to maintain a safe concentration of heavy metals in greenhouse soils.
Harpin proteins are well known as eliciters that induce multiple responses in plants, such as systemic acquired resistance, hypersensitive response, enhancement of growth, resistance to the green ...peach aphid, and tolerance to drought. Overexpression of Harpin-encoding genes enhances plant resistance to diseases in tobacco, rice, rape, and cotton; however, it is not yet known whether the expression of Harpin-encoding genes in vivo improves plant tolerance to abiotic stresses. The results of this study showed that overexpression of a Harpin-encoding gene hrf1 in rice increased drought tolerance through abscisic acid (ABA) signalling. hrf1- overexpression induces an increase in ABA content and promotes stomatal closure in rice. The hrf1 transgenic rice lines exhibited a significant increase in water retention ability, levels of free proline and soluble sugars, tolerance to oxidative stress, reactive oxygen species-scavenging ability, and expression levels of four stress-related genes, OsLEA3-1, OsP5CS, Mn-SOD, and NM_001074345, under drought stress. The study confirmed that hrf1 conferred enhanced tolerance to drought stress on transgenic crops. These results suggest that Harpins may offer new opportunities for generating drought resistance in other crops.
In this work, we study the microwave field driven domain wall (DW) motion in an antiferromagnetic nanowire, using the numerical calculations based on a classical Heisenberg spin model with the ...biaxial magnetic anisotropy. We show that a proper combination of a static magnetic field plus an oscillating field perpendicular to the nanowire axis is sufficient to drive the DW propagation along the nanowire. More importantly, the drift velocity at the resonance frequency is comparable to that induced by temperature gradients, suggesting that microwave field can be a very promising tool to control DW motions in antiferromagnetic nanostructures. The dependences of resonance frequency and drift velocity on the static and oscillating fields, the axial anisotropy, and the damping constant are discussed in details. Furthermore, the optimal orientations of the field are also numerically determined and explained. This work provides useful information for the spin dynamics in antiferromagnetic nanostructures for spintronics applications.
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•Synergetic alloying effects on stabilities of γ, γ’, and γ’’ in IN718 are unveiled.•Number of valence electrons at Fermi level largely governs the phase stability.•Mechanical maps of ...γ, γ’, and γ’’ in IN718 are drawn by high-throughput calculations.•The results provide the preferred composition range for the γ, γ’, and γ’’ phases.
The premature failure of the γ’’-strengthen mechanism restricts the further application of Inconel 718 superalloys at temperatures over 650 °C. Although numerous attempts have been made to improve the performance, the complex chemical composition and phase constitution still pose a great challenge to the development of IN718. We systematically explore the sole/synergetic effect of various alloying elements on stabilities of the matrix (γ) and the precipitates (γ’, γ’’) in IN718, and map their mechanical properties versus chemical compostions by employing high-throughput calculations. Results indicate that the promotive effect of Al and Ti on stability of γ’ phase exhibits a synergistic relationship, either over-low Al or Ti would obviously weaken the promotion. W is detrimental to stability of γ’ phase. Co yields a complicated effect on stabilities that depends on its sublattice position and the Al and Ti contents. By drawing the mechanical maps, it shows that the preferred composition range for the phases with desired properties is roughly demarcated in theory. The Al, Ti, and Nb concentrations need to be cautiously altered due to their conflicting effects on stabilities and mechanical properties of the phases. Alloying Co is encouraged to enhance the properties while alloying W might be theoretically deprecated.
Glioma presents high incidence and poor prognosis, and therefore more effective treatments are needed. Studies have confirmed that long non-coding RNAs (lncRNAs) basically regulate various human ...diseases including glioma. It has been theorized that HAS2-AS1 serves as an lncRNA to exert an oncogenic role in varying cancers. This study aimed to assess the value of lncRNA HAS2-AS1 as a diagnostic and prognostic marker for glioma.
The miRNA expression data and clinical data of glioma were downloaded from the TCGA database for differential analysis and survival analysis. In addition, pathological specimens and specimens of adjacent normal tissue from 80 patients with glioma were used to observe the expression of HAS2-AS1. The receiver operating characteristic (ROC) curve was used to analyze the diagnostic ability and prognostic value of HAS2-AS1 in glioma. Meanwhile, a Kaplan–Meier survival curve was plotted to evaluate the survival of glioma patients with different HAS2-AS1 expression levels.
HAS2-AS1 was significantly upregulated in glioma tissues compared with normal tissue. The survival curves showed that overexpression of HAS2-AS1 was associated with poor overall survival (OS) and progression-free survival (PFS). Several clinicopathological factors of glioma patients, including tumor size and WHO grade, were significantly correlated with HAS2-AS1 expression in tissues. The ROC curve showed an area under the curve (AUC) value of 0.863, indicating that HAS2-AS1 had good diagnostic value. The ROC curve for the predicted OS showed an AUC of 0.906, while the ROC curve for predicted PFS showed an AUC of 0.88. Both suggested that overexpression of HAS2-AS1 was associated with poor prognosis.
Normal tissues could be clearly distinguished from glioma tissues based on HAS2-AS1 expression. Moreover, overexpression of HAS2-AS1 indicated poor prognosis in glioma patients. Therefore, HAS2-AS1 could be used as a diagnostic and prognostic marker for glioma.
Los gliomas presentan una alta incidencia y un mal pronóstico, por lo que es necesario un tratamiento más efectivo. Algunos estudios han confirmado que los ARN no codificantes de cadena larga (ARNncl) regulan diferentes enfermedades, entre las que se incluyen los gliomas. Se ha postulado que HAS2-AS1 actúa como un ARNncl, con un efecto oncogénico en diferentes tipos de cáncer. Este estudio tiene como objetivo analizar el valor del ARNncl HAS2-AS1 como marcador diagnóstico y pronóstico de glioma.
Descargamos los datos clínicos y de expresión de micro-ARN de la base de datos del Atlas del Genoma del Cáncer (TCGA) para realizar el análisis diferencial y de supervivencia. También analizamos la expresión de HAS2-AS1 en muestras patológicas y muestras de tejido adyacente normal de 80 pacientes con glioma. Para analizar la capacidad diagnóstica y el valor pronóstico de HAS2-AS1 en el glioma, recurrimos a la curva ROC. También utilizamos curvas de Kaplan-Meier para evaluar la supervivencia de los pacientes con glioma con diferentes niveles de expresión de HAS2-AS1.
La expresión de HAS2-AS1 era significativamente mayor en las muestras patológicas que en el tejido normal. Las curvas de supervivencia demostraron que la sobreexpresión de HAS2-AS1 estaba relacionada con una menor supervivencia general y supervivencia libre de progresión. Algunos factores clínico-patológicos de los pacientes con glioma, como el tamaño del tumor y su grado, según la clasificación de la OMS, mostraron una correlación significativa con la expresión de HAS2-AS1 en los tejidos afectados. La curva ROC mostró un área bajo la curva de 0,863, lo que indica que la expresión de HAS2-AS1 posee un importante valor diagnóstico. El área bajo la curva de la supervivencia general estimada fue de 0,906; para la supervivencia libre de progresión estimada, de 0,88. Ambos valores muestran que la sobreexpresión de HAS2-AS1 se asocia con un mal pronóstico.
Los tejidos normales pueden distinguirse claramente de los tejidos afectados por glioma en función de la expresión de HAS2-AS1. Además, la sobreexpresión de HAS2-HS1 fue indicativa de mal pronóstico en los pacientes con glioma. Por tanto, HAS2-AS1 podría utilizarse como marcador diagnóstico y pronóstico en el manejo del glioma.
A theoretical study on the dynamics of an antiferromagnetic (AFM) skyrmion is indispensable for revealing the underlying physics and understanding the numerical and experimental observations. In this ...work, we present a reliable theoretical treatment of the spin-current induced motion of an AFM skyrmion in the absence and presence of pinning defect. For an ideal AFM system free of defect, the skyrmion motion velocity as a function of the intrinsic parameters can be derived, based on the concept that the skyrmion profile agrees well with the 360° domain-wall formula, leading to an explicit description of the skyrmion dynamics. However, for an AFM lattice containing a defect, the skyrmion can be pinned and the depinning field as a function of damping constant and pinning strength can be described by Thiele's approach. It is revealed that the depinning behavior can be remarkably influenced by the time-dependent oscillation of the skyrmion trajectory. The present theory provides a comprehensive scenario for manipulating the dynamics of AFM skyrmion, informative for future spintronic applications based on antiferromagnets.
Magnetic rare earth high entropy alloy (HEA) TbDyHoEr is a candidate material for magnetic refrigeration due to its ideal ‘table-like’ magnetocaloric effect (MCE). In order to further enhance the MCE ...and reduce the amount of rare earth, TbDyHoErM (M = Ti, Co) were prepared by adding 3d transition metals Ti and Co with the same hexagonal close-packed (HCP) structure to the TbDyHoEr matrix. The addition of Ti does not change the HCP structure of matrix, and maintains excellent ‘table-like’ MCE of the matrix. The magnetic entropy change (Δ
S
M
) and refrigeration capacity (RC) value of TbDyHoErTi are 6.66 J·kg
−1
K
−1
and 779.22 J·kg
−1
, respectively. After the addition of Co, a new phase R
3
T (R = rare earth) was preferentially formed, and TbDyHoErCo is composed of R
3
T phase and HCP disordered solid solution. This mixture structure raises the Δ
S
M
of TbDyHoErCo to 11.32 J·kg
−1
K
−1
, but the RC value drops to 482.66 J·kg
−1
due to the disappearance of ‘table-like’ effect. The results not only provide direction for reducing the amount of rare earth, but also provide new choices for practical medium temperature magnetic refrigeration applications, which can be used in natural gas liquefaction, biological organ storage in medicine and quantum computer heat dissipation.
Active flow control for aerofoils has been proven to be an effective way to improve the aerodynamic performance of aircraft. A conceptual hybrid design with surfaces embedded with Shape-Memory Alloy ...(SMA) and trailing Macro Fibre Composites (MFC) is proposed to implement active flow control for aerofoils. A Computational Fluid Dynamics (CFD) model has been built to explore the feasibility and potential performance of the proposed conceptual hybrid design. Accordingly, numerical analysis is carried out to investigate the unsteady flow characteristics by dynamic morphing rather than using classical static simulations and complicated coupling. The results show that camber growth by SMA action could cause an evident rise of Cl and Cd in the take-off/landing phases when the Angle-of-Attack (AoA) is less than 10°. The transient tail vibration behaviour in the cruise period when using MFC actuators is studied over wide ranges of frequency, AoA and vibration amplitude. The buffet frequency is locked in by the vibration frequency, and a decrease of 1.66–2.32% in Cd can be achieved by using a proper vibration frequency and amplitude.
Abstract
Hydro-pneumatic suspension is the important part of running system of vehicle, with wider working frequency band, frequent reciprocating motion and heavy impact load, whose important ...indicator is sealing performance. The heat generation law of hydro-pneumatic suspension is obtained under the sinusoidal excitation by calculating method, and the bench test of the temperature suppression is successfully achieved.
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