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The establishment of a financial system should not only consider the current situation, but also need to refer to the past. Due to the memory of the fractional derivative, a fractional-order system can more effectively describe the historical significance of the financial system. Most scholars use the prediction–correction scheme to study fractional-order systems. This paper provides a higher-precision numerical method for the financial system, which more effectively simulate the system. Based on the definition of the Grünwald–Letnikov fractional derivative, the integer-order system with nonconstant demand elasticity is extended to the fractional-order setting, and its dynamic behavior is studied, with some novel chaotic attractors found. The research results are helpful for improving the understanding of the financial system and the financial market and for predicting financial risks. [ABSTRACT FROM AUTHOR]

In order to stop and reverse land degradation and curb the loss of biodiversity, the United Nations 2030 Agenda for Sustainable Development proposes to combat desertification. In this paper, a fractional vegetation–water model in an arid flat environment is studied. The pattern behavior of the fractional model is much more complex than that of the integer order. We study the stability and Turing instability of the system, as well as the Hopf bifurcation of fractional order α , and obtain the Turing region in the parameter space. According to the amplitude equation, different types of stationary mode discoveries can be obtained, including point patterns and strip patterns. Finally, the results of the numerical simulation and theoretical analysis are consistent. We find some novel fractal patterns of the fractional vegetation–water model in an arid flat environment. When the diffusion coefficient, d, changes and other parameters remain unchanged, the pattern structure changes from stripes to spots. When the fractional order parameter, β , changes, and other parameters remain unchanged, the pattern structure becomes more stable and is not easy to destroy. The research results can provide new ideas for the prevention and control of desertification vegetation patterns. [ABSTRACT FROM AUTHOR]

The aim of this investigation was to evaluate the effect of microstructure heterogeneity on the tensile and low cycle fatigue properties of electron beam welded (EBW) Ti6Al4V sheets. To achieve this goal, the tensile and low cycle fatigue property in the EBW joints and base metal (BM) specimens is compared. During the tensile testing, digital image correlation technology was used to measure the plastic strain field evolution within the specimens. The experimental results showed that the tensile ductility and low cycle fatigue strength of EBW joints are lower than that of BM specimens, mainly because of the effect of microstructure heterogeneity of the welded joint. Moreover, the EBW joints exhibit the cyclic hardening behavior during low fatigue process, while BM specimens exhibit the cyclic softening behavior. Compared with the BM specimens with uniform microstructure, the heterogeneity of microstructure in the EBW joint is found to decrease the mechanical properties of welded joint. [ABSTRACT FROM AUTHOR]

In order to ascertain the distribution characteristics of soil heavy metal pollution and main pollution sources in a small watershed in the southern mountainous area of Ningxia and to ensure the quality of the soil environment, the contents of heavy metals Pb, Ni, Zn, Mn, Cu, Cr, and Cd in 260 surface soil samples (0-20 cm) were collected and determined. Based on the soil background value in Ningxia, the soil heavy metal pollution status and potential ecological risk were evaluated through the single factor index, Nemera composite index, and potential ecological risk index, and the method of combining positive definite matrix factor analysis (PMF) and Kriging interpolation was used to analyze the soil heavy metal spatial distribution and source. The results showed that the average contents of ω (Pb), ω (Ni), ω (Zn), ω (Mn), ω (Cu), ω (Cr), and ω (Cd) were 31.42, 36.22, 62.89, 546.18, 22.26, 61.90, and 0.18 mg·kg -1 , respectively. Except for Ni, the other elements were higher than the background value of Ningxia but lower than the background value of agricultural soil pollution risk selection criteria and green food environmental quality standards. The Nemera composite index showed that the proportions of mild, moderate, and severe heavy metal pollution were 71.92%, 19.23%, and 1.54%, respectively. The potential ecological risks were mainly minor risks, accounting for 98.85%. In addition, there were a very small number of samples with medium potential ecological risk levels, accounting for 1.15% of the total number of samples. Source analysis showed that the main sources of soil heavy metals in the small watershed in the mountainous area of southern Ningxia were mixed sources of fertilization and industrial emissions (12.6%), agricultural activity sources (23.5%), natural parent material sources (27.6%), mixed sources of pesticide use and mining development emissions (17.7%), and atmospheric deposition sources (18.6%).

Objective: To explore the effects on Aβ plaques of neural stem cells transplanted into an Alzheimer disease mouse model., Methods: A total of twenty 12-months-old APP+PS1 double transgenic AD mice were randomly divided into two groups.One group received neural stem cells transplantation, that was NSC group, another mice received an equal quantity 0.01 mol/L PBS, as positive control group. After 5 weeks transplantation, the total number of Aβ plaques examined by immunohistochemistry, the ratio of compact of Aβ plaques by TS staining, and whether NSCs migrate into Aβ plaques by immunofluorescence monitoring., Results: There was no difference in total number of Aβ plaques between NSC group (181 ± 12) and PBS (179 ± 14) group after transplantation (P > 0.05). There was no difference in the number of TS+ plaques between NSC group (54.9%) and PBS (55.7%) group after eight weeks NSCs transplantation (P > 0.05). (2) However, engrafted NSCs showed partial chemotaxis toward Aβ plaques., Conclusion: NSCs transplantation did not have a significant impact on Aβ plaques of AD mice, but the tropism of engrafted NSCs may be capable of replacing lost or damaged cells and reverse the course of AD mice in some extent.

Objective: To explore the feasibility of in vivo labeling of adult rat neural progenitor cells (NPCs) in subventricular zone (SVZ) with superparamagnetic iron oxide particles (SPIOs) for tracking of magnetic resonance imaging (MRI)., Methods: A total of 7 SD rats were stereotactically injected with 3 µl SPIOs (7 mg Fe/ml) into anterior horn of right lateral ventricle and then 5-bromo-2'-deoxyuridine (BrdU) was injected intraperitoneally once daily for 1 week. MRI was performed at 1, 3, 7 and 14 days post-injection. After the final MRI scan, all rats were transcardially perfused and their brains removed and fixed. The sections were processed for Prussian blue iron staining and Prussian blue plus BrdU immunohistochemical staining., Results: In all experimental animals, SPIOs were predominantly located in the anterior horn of right lateral ventricle and partial SPIOs entered the ventricular system. A needle path and a distribution of SPIOs along rostral migratory stream (RMS) towards olfactory bulb (OB) were depicted at the sagittal view of T2(*)WI, moderate MR artifact was visible and SPIOs tracking NPCs were successful (success rate of 100%). The result of staining showed SPIOs labeling NPCs were effective. And the labeling rates were 75.5%, 42.3%, 23.6% in SVZ, RMS and OB respectively., Conclusion: Effective in vivo labeling of adult rat NPCs in SVZ with SPIOs is feasible. And dynamical migration of labeling NPCs along RMS towards OB may be visualized on MRI.

Objective: To explore the effects of a continuous low-dose of X-ray upon neuronal morphology and expression of microtubule associated protein-2 (MAP-2) in hippocampus of young rats., Methods: A total of 18 Sprague-Dawley rats aged 35 days were randomly divided into two irradiated groups and one control group (n = 6 each). The irradiated groups received different doses of 0.2 mGy/d, 1.0 mGy/d for 7 consecutive days while the control group sham radiation. The hippocampal pyramidal cell was observed by HE staining, the expression of MAP-2 by immunohistochemistry and Western blot, and the morphologies of microtubule and synapse in CA1 by electron microscopy., Results: (1) The phenomenon of neurodegeneration was observed in the 1.0 mGy group while the control and 0.2 mGy groups were normal; (2) the average optical density of positive MAP-2 protein significantly decreased in the 1.0 mGy group (0.242 ± 0.017) in the region of CA1 versus the control group (0.282 ± 0.016) (F = 14.419, P = 0.005). And the average optical density of positive MAP-2 significantly increased in the 0.2 mGy group (0.331 ± 0.017) compared with the control group (F = 21.700, P = 0.002). The expression of total MAP-2 significantly decreased in the 1.0 mGy group (0.332 ± 0.001) versus the control group (0.370 ± 0.012) (F = 28.055, P = 0.000). And the expression of total MAP-2 significantly increased in the 0.2 mGy group (0.455 ± 0.018) versus the control group (F = 61.974, P = 0.002); (3) there were the reduction of microtubule and the damage of postsynaptic density (PSD) in the 1.0 mGy group in hippocampal CA1. Increased microtubule and normal synapses were found in the 0.2 mGy group in hippocampal CA1., Conclusion: The expression of MAP-2 is strongly associated with the integrity of hippocampal neurons in young rats. The 0.2 mGy group may promote the proliferation of hippocampal microtubule in hippocampus and further promote the expression of MAP-2. And the damage of microtubule and PSD on neuron could reduce the expression of MAP-2 in the 1.0 mGy group.

Objective: To observe and investigate the neuroimaging characters in early progression of transgenic Alzheimer's disease (AD) mice model, and make sure the diagnosis value of 7.0 T high field magnetic resonance microimaging (MRMI)., Methods: APP/PS-1 transgenic mice aged 3, 6, 9 months and the same aged wild type mice were each divided into 6 groups (6 mice in every groups) based on age. The mice brains were scaned with 7.0T high magnetic field MR. Then the mice were killed. The Aβ immunohistochemistry examination was analyzed in the mice brains specimens, and pathological changes were in comparison with the T(2) weighted imaging in the mice brains., Results: There were a few Aβ plaques in the brains of 6 months APP/PS-1 transgenic mice, while Aβ plaques were increased both in number and volume in the cerebral cortex and hippocampus of 9 months AD mice. The brains of APP/PS-1 double transgenic mice of 3, 6 months and the control group mice were not showed intensity loss on T(2) weighted MR images, while the signal intensity loss was visualized in the cerebral cortex and hippocampus of 9 months AD mice., Conclusion: 7.0T high magnetic field MR could display Aβ plaques in the brains of APP/PS-1 double transgenic mice of 9 months and it is helpful to diagnosis early AD.

Objective: To explore the effect of low doses X-ray on proliferation of hippocampal pyramidal cell in the area of CA1 in prenatal rat and its relevant mechanism., Methods: A total of 25 pregnant rats were randomly divided into four experimental groups and one control group. The experimental groups, in a duration of consistent 18 days, respectively received different doses as follows: 0.015 mGy/d, 0.03 mGy/d, 0.06 mGy/d and 0.09 mGy/d. The control group received sham radiation. To observe the density and width of hippocampal pyramidal cell in the area of CA1 by HE stained and observe the expression of the ERK1/2 by IHM., Results: (1) Except C group, all other groups presented increment in width of the level of hippocampal pyramidal cell, compared with C group; H group, M group, L1 group and L2 group were higher than that (F value respectively were 8.475, 33.42, 14.395, 44.955; P value respectively were 0.002, 0.048, 0.030, 0.012). But the phenomenon of inhomogeneity in width in H group was observed, at the same time, the density of cell in H group became looser (F = 4.466, P = 0.017). (2) The expression of ERK1/2 in the hippocampus CA1 was seen in cytoplasm of every group, the average optical density of positive ERK1/2 protein significantly increased in L1 group and L2 group, compared with control group respectively (F value respectively were 4.561, 4.103, P value respectively were 0.044, 0.035)., Conclusion: Low doses X-ray could promote proliferation of hippocampus CA1 cell in prenatal. The reason could be the increment of the ERK1/2 protein induced by X-ray. When the doses reached 0.09 mGy/d, the excesses proliferation phenomenon was observed.