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Recent studies have confirmed that pain memory is often accompanied by negative emotions. Electroacupuncture (EA) can block the retrieval of painful memories, thereby alleviating the associated negative behaviors. However, the underlying mechanism is poorly understood. This study revealed that the effect of EA on pain memory-induced negative behaviors is related to the mediation of GABAergic neuron activity and GABA receptor expression in the rostral anterior cingulate cortex (rACC). Previous studies have shown that the rACC is a crucial area for regulating nociceptive behaviors and negative emotions in pain memory models. The GABAergic neurons and receptors in the rACC are largely involved in pain sensation and related effects. However, the relationships among pain memory, GABAergic neurons and receptors in the rACC have not been investigated. In this study, we established a pain memory model via secondary plantar cross-injection of carrageenan and EA treatment. Using chemogenetic methods and behavioral assessments of pain and negative emotion, we found that early excitation of GABAergic neurons in the rACC blocked the recall of pain memories and reduced anxiety-like behaviors in pain memory model rats. Furthermore, pharmacological methods revealed that excitation of GABAA and GABAB receptors in the rACC blocks hyperpathia associated with pain memory and pain-induced anxiety-like behaviors, while inhibition of GABAA and GABAB receptors reverses these effects. These results suggest that EA may alleviate pain and associated anxiety-like behaviors related to pain memories through the activation of GABAergic neurons and excitation of GABAA and GABAB receptors in the rACC. [ABSTRACT FROM AUTHOR]

Pain memory is commonly considered an underlying cause of chronic pain and is also responsible for a range of anxiety. Electroacupuncture (EA) has been shown to ameliorate pain memories and exert anti-anxiety effects. Previous research has indicated that GABAergic neurons and/or GABA receptors (GABARs) in the midcingulate cortex (MCC) have potential associations with chronic pain and anxiety. However, there is no known empirical research that has specifically studied the effects of EA on the GABAergic system in the MCC. Here, we used cross-injection of carrageenan to establish the pain memory rats model. Immunofluorescence were used to detect the excitability of GABAergic neurons within MCC. Von Frey filament, elevated zero maze, and open field tests were used to measure mechanical allodynia and anxiety-like behaviors, combined with chemogenetic and pharmacologic technologies. Finally, this study provides evidence that pain memories contribute to generalized negative emotions and that downregulating the activity of GABAergic neurons within MCC could block pain memories and reverse anxiety emotion. Specifically, GABABR is involved in pain memory and related anxiety-like behaviors. Activation of GABAergic neurons in the MCC did not reverse the effects of EA on pain memories and related anxiety-like behaviors, whereas these effects could be reversed by a GABABR agonist. These findings highlight the functional significance of GABABR in the EA-mediated attenuation of pain memories and related anxiety-like behaviors in rats. [ABSTRACT FROM AUTHOR]

Geosynthetic-reinforced pile foundations (GRPF) are widely applied for the construction of railways to improve the natural weak foundation formed with soft soil. This paper presents centrifuge model tests to study the possible changes in stress distribution in the GRPF under increasing dynamic loads. A self-designed electromagnetic vibration loading device was developed and effectively validated under similarity scales in centrifuge model tests. One test focuses on the static loading test to compare with the load level in the dynamic loading test. Another two tests study the behavior of GRPF under dynamic loading with the self-developed load device. These two tests reveal the influence of the geosynthetic. The results show the long-term dynamic loading significantly affects the dynamic stress between the piles of the GRPF. A small dynamic load level can benefit the formation of soil arching while large dynamic load level can cause adverse impacts on the GRPF. More dynamic stress is applied to the soft soil between piles with increasing load levels and the dynamic pile–soil stress ratio decreases. Also, the changes of static stress on the pile top indicate the soil arching can collapse under a larger dynamic load level. The residual stress along the pile after dynamic stress indicates that the shaft resistance may change. Moreover, the existence of geosynthetic can help enhance the performance of GRPF by helping re-distribute the stress on pile and soil as well as improving the stability of soil arching. [ABSTRACT FROM AUTHOR]

Chronic pain, such as neuropathic pain, causes anxiety and other negative emotions, which aggravates the pain sensation and increases the risk of chronic pain over time. Dopamine receptor D1 (DRD1) and dopamine receptor D2 (DRD2) in the basolateral amygdala (BLA) have been implicated in mediating anxiety-related behaviors, but their potential roles in the BLA in neuropathic pain-induced anxiety have not been examined. Electroacupuncture (EA) is commonly used to treat chronic pain and emotional disorders, but it is still unclear whether EA plays a role in analgesia and anxiety relief through DRD1 and DRD2 in the BLA. Here, we used western blotting to examine the expression of DRD1 and DRD2 and pharmacological regulation combined with behavioral testing to detect anxiety-like behaviors. We observed that injection of the DRD1 antagonist SCH23390 or the DRD2 agonist quinpirole into the BLA contributed to anxiety-like behaviors in naive mice. EA also activated DRD1 or inhibited DRD2 in the BLA to alleviate anxiety-like behaviors. To further demonstrate the role of DRD1 and DRD2 in the BLA in spared nerve injury (SNI) model-induced anxiety-like behaviors, we injected the DRD1 agonist SKF38393 or the DRD2 antagonist sulpiride into the BLA. We found that both activation of DRD1 and inhibition of DRD2 could alleviate SNI-induced anxiety-like behaviors, and EA had a similar effect of alleviating anxiety. Additionally, neither DRD1 nor DRD2 in the BLA affected SNI-induced mechanical allodynia, but EA did. Overall, our work provides new insights into the mechanisms of neuropathic pain-induced anxiety and a possible explanation for the effect of EA treatment on anxiety caused by chronic pain. [ABSTRACT FROM AUTHOR]

In order to reduce the effects of the low strength and high compressibility of soft soil, geosynthetic-reinforced pile foundations (GRPF) are widely applied for the construction of high-speed railways. Though its reinforcement effect is proved acceptable in practices so far, it is unclear whether it will keep this performance as the train speed continues increasing. Since it is impossible to study the problem in field tests, only mathematical and physical models can be used. However, the nonlinear behaviour of the soft soil complicates the use of analytical models. Therefore, this paper presents a small-scale model test to study the possible changes in stress distribution and deformation in the GRPF under increasing dynamic loads. One test with a natural foundation, without piles or geosynthetic, shows the difference with a similar construction with GRPF foundation. Furthermore, three GRPF tests show the influence of the embankment thickness. The results show the long-term dynamic loading significantly affects the dynamic stress and displacements of the subsoil between the piles of the GRPF. This effect can be divided into three stages with an increasing level of load amplitude: no impact, advantageous impact, and adverse impact. When the dynamic load reaches the adverse impact stage, the long-term dynamic loads reduce the dynamic pile–soil stress ratio, which means that more soil settlement will develop, because more dynamic stress is applied to the soft soil. The test results show that the reduction in dynamic stress on the subsoil in the GRPF construction is clearly lower than the dynamic stress on the natural foundation, due to the existence of rigid piles. Moreover, a thicker embankment gives significantly lower dynamic stresses on the subsoil between the piles. For the thickest embankment tested, the adverse impact stage was not found at all: the arching kept enhancing under long-term dynamic loading with high load amplitudes. [ABSTRACT FROM AUTHOR]

We studied the local structure and properties of six-fold coordinated silicon (Si[6]) in BaO-SiO2-P2O5 glasses. Nuclear magnetic resonance (NMR) and Raman spectroscopy revealed the existence of six-fold coordinated silicon species and network former units (NFUs) in the BaO-SiO2-P2O5 glasses. The glass transition temperature (Tg), which was measured by differential scanning calorimetry, increased rapidly along with the increase of SiO2 from 0 to 10 mol%, then declined and finally increased again, which showed a "Z" trend along with the increase of SiO2 while the density of the glasses showed the opposite trend. When the addition of SiO2 is 16 mol%, Tg decreased to an extremely low value (807.9 K). Besides, the Vickers indentation hardness (Hv) had been significantly enhanced from 4.66 to 6.63 GPa by adding 16 mol% SiO2. Furthermore, the liquid fragility index (m) of the glasses declined slowly firstly and then increased rapidly when the amount of SiO2 is greater than 13 mol%. [ABSTRACT FROM AUTHOR]

Artificial ground freezing method, is a popular technique applied in coastal soft soil area for underground engineering construction. This method can bring some side effects, like frost heave and thaw settlement, due to the water migration in soil during freezing-thawing process. A self-designed one-dimensional freezing apparatus is used to study the deformation performance of the reconstituted soft clay from Shanghai 4th layer during freezing-thawing process. Test results show that total frost heave amount increases with decreasing boundary freezing temperature while it remains with the variation of initial water content in the test. The deformation of multilayers during freezing process reveals compression phenomenon due to the water migration in the soil samples. The compression area is the main part contributed to thaw settlement. Besides, a prediction model is established with void ratio as a variable to connect frost-heave model with thaw-settlement model. FDM (Finite Difference Method) method is used for computation through compiling code in MATLAB software. Comparison shows that compression phenomenon is necessary to be considered when calculating thaw settlement. This study provides valuable reference to the deformation control of soil in the construction of artificial ground freezing. [ABSTRACT FROM AUTHOR]