Search

Introduction: The variation of organic carbon content in spoil heaps is closely related to improving soil structure, maintaining soil fertility, and regulating soil carbon cycling balance. Analyzing the soil organic carbon content and related driving factors during the natural vegetation restoration process of spoil heaps is of great significance for promoting the accumulation of soil organic carbon in the spoil heaps. Methods: we selected spoil heaps with the same number of years of restoration to research the variations in soil organic carbon components under different vegetation types (grassland: GL, shrubland: SL, secondary forest: SF) and compared the results with those on bare land (BL). Results: Our results showed that vegetation type and soil depth significantly affect the content of soil organic carbon components. There was no difference in soil organic carbon components between SF and SL, but both were considerably superior to GL and BL (p<0.05), and the particulate organic carbon (POC) and light fraction organic carbon (LFOC) contents of SL were the highest. A significant positive linear correlation existed between SOC and active organic carbon components. Pearson's correlation and redundancy analysis showed that the available potassium (AK) and total nitrogen (TN) contents and gravel content (GC) in the BL soil significantly impacted soil organic carbon. When vegetation is present, TN, total phosphorus (TP), and Fine root biomass (FRB) significantly affect soil organic carbon. Structural equation modelling (SEM) shows that AK and soil moisture content (SMC) directly affect the organic carbon composition content of BL, When there is vegetation cover, fine root biomass (FRB) had the largest total effect in the SEM. Soil bulk density (BD) has a negative impact on soil organic carbon, especially in the presence of vegetation. Conclusion: These findings suggest that vegetation restoration can significantly increase soil organic carbon content, FRB, AK, and TN play important roles in enhancing soil organic carbon. Supplementation with nitrogen and potassium should be considered in the bare land stage, and shrubs nitrogen-fixing functions and well-developed roots are more beneficial for the accumulation of soil organic carbon. [ABSTRACT FROM AUTHOR]

Placenta-specific 8 (PLAC8) is closely associated with the proliferation, apoptosis and autophagy of several tumor cells. However, the expression and function of PLAC8 in oral squamous cell carcinoma (OSCC) remain unknown. Therefore, the present study investigated the function and mechanism of PLAC8 in OSCC. Reverse transcription-quantitative PCR and western blot analyses were performed to quantify the expression of PLAC8 in OSCC cell lines. The function of PLAC8 in OSCC was investigated via transfection, the Transwell and Cell Counting Kit-8 assays, immunofluorescence staining and western blotting. The results demonstrated that PLAC8 exspression was downregulated in OSCC cell lines. PLAC8 inhibited the cell proliferation in OSCC. In addition, PLAC8 restrained invasion and epithelialmesenchymal transition of OSCC cells. Furthermore, β-catenin helped to repress PLAC8 expression by regulating the Wnt/β- catenin and PI3K/Akt/GSK3β signaling pathways in OSCC cells. Collectively, the results of the present study suggest that PLAC8 acts as a tumor suppressor in OSCC by downregulating β-catenin. [ABSTRACT FROM AUTHOR]

Background: Globus pharyngeus is common and has a low cure rate. Its etiology is complex and reported to be associated with laryngopharyngeal reflux (LPR). However, some patients with globus do not exhibit any reflux symptoms or respond to proton pump inhibitors (PPIs) treatments. The purpose of this study was to clarify the related risk factors of these patients with a final objective of improving the curative effect.Methods: Forty two patients afflicted with globus pharyngeus (G group) and 38 patients without globus pharyngeus (NG group) were included in this study. According to the laryngopharyngeal Reflux Symptom Index and the response to PPIs treatments, the patients were further divided into reflux groups (G-R, NG-R) and non-reflux groups (G-NR, NG-NR). High Resolution Manometry (HRM) was performed to assess esophageal motility. Questionnaires, including categories such as life exposure factors, were conducted.Results: a) The average resting and residual pressures of the upper esophageal sphincter (UES) in the G-NR group was higher than in the NG-NR and NG-R groups (P < 0.05). b) The average resting and residual pressures of the lower esophageal sphincter showed no differences between the G-NR group and the NG-NR group (P > 0.05). c) The esophageal distal contractile integral score of the G-NR group was not different from the NG-NR group (P > 0.05). d) Compared to the NG-NR group, the G-NR group showed higher incidence of stress, smoking, drinking, high salt and anxiety (P < 0.05).Conclusions: Globus pharyngeus without LPR may occur due to high UES pressure. Stress, smoking, alcoholic drinking, high salt and anxiety may be its risk factors. [ABSTRACT FROM AUTHOR]

Background: Cathepsin C (Cat C) functions as a central coordinator for activation of many serine proteases in inflammatory cells. It has been recognized that Cat C is responsible for neutrophil recruitment and production of chemokines and cytokines in many inflammatory diseases. However, Cat C expression and its functional role in the brain under normal conditions or in neuroinflammatory processes remain unclear. Our previous study showed that Cat C promoted the progress of brain demyelination in cuprizone-treated mice. The present study further investigated the Cat C expression and activity in lipopolysaccharide (LPS)-induced neuroinflammation in vivo and in vitro. Methods: C57BL/6 J mice were intraperitoneally injected with either 0.9% saline or lipopolysaccharide (LPS, 5 mg/ kg). Immunohistochemistry (IHC) and in situ hybridization (ISH) were used to analyze microglial activation, TNF-α, IL- 1β, IL-6, iNOS mRNAs expressions and cellular localization of Cat C in the brain. Nitrite assay was used to examine microglial activation in vitro; RT-PCR and ELISA were used to determine the expression and release of Cat C. Cat C activity was analyzed by cellular Cat C assay kit. Data were evaluated for statistical significance with paired t test. Results: Cat C was predominantly expressed in hippocampal CA2 neurons in C57BL/6 J mice under normal conditions. Six hours after LPS injection, Cat C expression was detected in cerebral cortical neurons; whereas, twenty-four hours later, Cat C expression was captured in activated microglial cells throughout the entire brain. The duration of induced Cat C expression in neurons and in microglial cells was ten days and three days, respectively. In vitro, LPS, IL-1β and IL-6 treatments increased microglial Cat C expression in a dose-dependent manner and upregulated Cat C secretion and its activity. Conclusions: Taken together, these data indicate that LPS and proinflammatory cytokines IL-1β, IL-6 induce the expression, release and upregulate enzymatic activity of Cat C in microglial cells. Further investigation is required to determine the functional role of Cat C in the progression of neuroinflammation, which may have implications for therapeutics for the prevention of neuroinflammation-involved neurological disorders in the future. [ABSTRACT FROM AUTHOR]

Conventional viscoelastic dampers based on common elastomers cannot adjust their stiffness to adapt to complex vibration conditions. To overcome this shortcoming, a novel stiffness tunable viscoelastic (STV) damper is proposed in this study. Electrorheological elastomers (EREs), which present a tunable storage modulus by applying electric fields, were used as the key materials to provide the STV damper with electric field responsive stiffness. A series of experiments was conducted to study the dynamic mechanical properties of the STV damper under different displacement amplitudes, frequencies, and electric field strengths. The results indicated that the force–displacement hysteretic curve of the STV damper depends on displacement amplitude and frequency, and could be actively controlled by the electric field strength. Consequently, the equivalent stiffness, equivalent damping, equivalent damping ratio, and energy dissipation capacity of the STV damper were electric field responsive terms. A mechanical model of the STV damper was established on the basis of the material constitutive. The simulation results obtained by the model agreed well with the experimental data, indicating that the model can be used for semi-active control of the STV dampers. [ABSTRACT FROM AUTHOR]