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Recent evidence has demonstrated that abnormal expression and regulation of circular RNA (circRNAs) are implicated in the development and progression of various tumors. The aim of this study was to investigate the effects of circ_SMA4 in Gastrointestinal Stromal Tumors (GISTs) malignant progression. Human circRNAs microarray analysis was conducted to identify differentially expressed (DE) circRNAs in GISTs. The effect of circ_SMA4 on cell proliferation, invasion, migration, and apoptosis was assessed in both in vitro and in vivo settings. Dual-luciferase reporter assay, RT-qPCR, Western-blot, and rescue assay were employed to confirm the interaction between circ_SMA4/miR-494-3p/ KIT axis. The results revealed that circ_SMA4 was significantly upregulated in GISTs, and exhibited high diagnostic efficiency with an AUC of 0.9824 (P < 0.01). circ_SMA4 promoted cell proliferation, invasion, migration, while inhibiting apoptosis in GISTs cells, both in vitro and in vivo. Silencing circ_SMA4 partially inhibited GISTs malignant progression. Additionally, circ_SMA4 acted as a competing endogenous RNA (ceRNA) by targeting miR-494-3p, and KIT was identified as a functional gene for miR-494-3p in GISTs. Furthermore, the results confirmed that circ_SMA4/miR-494-3p/ KIT axis plays a role in activating the JAK/STAT signaling pathway in GISTs. Therefore, for the first time, we have identified and emphasized that circ_SMA4 is significantly upregulated and plays an oncogenic role in GISTs by sponging miR-494-3p to activate the KIT/JAK/STAT pathway. These findings underscore circ_SMA4 may serve as a novel diagnostic biomarker and therapeutic target for GISTs. [ABSTRACT FROM AUTHOR]

Background: Iodine is an essential element for the biosynthesis of thyroid-stimulating hormone (TSH). Both excessive and deficient iodine are major risk factors for thyroid diseases, including thyroid dysfunction, thyroid nodules, and thyroid autoimmunity (TAI). This study aimed to elucidate the relationship between iodine status and the prevalence of thyroid diseases through a national cross-sectional epidemiological survey in Jiangxi province (China). Methods: This population-based, cross-sectional study enrolled 2636 Chinese local inhabitants who aged over 18 years old from April to August in 2015. Physical examination was performed and biochemical indices, urinary iodine concentration (UIC), and TSH level were measured. The Chi-square test, nonparametric test, and 4 multivariate logistic regression models adjusted for risk factors were applied to analysis. Spearman correlation coefficients were calculated to investigate the relationship between iodine intake level and the prevalence of thyroid diseases. Results: The median UIC was 176.4 μg/L, and a significant difference was found in median UIC between men (182.45 μg/L) and women (169.25 μg/L) (P = 0.03). Among these study subjects, 14.4%, 44.5%, 26.1%, and 15.0% had deficient, adequate, more than adequate, and excessive iodine concentrations, respectively. The prevalence rates of hyperthyroidism, subclinical hyperthyroidism, hypothyroidism, subclinical hypothyroidism, thyroid nodules, and TAI were 0.91%, 0.57%, 0.34% and 7.89%, 9.45%, and 12.7%, respectively. Significant differences were found in iodine status, waist circumstance, systolic blood pressure (SBP), diastolic blood pressure (DBP), total cholesterol (TC), TSH, thyroid nodules, and TAI between men and women (P < 0.05). Compared with those with adequate UIC, subjects with excessive UIC had higher prevalence rates of thyroid dysfunction (odds ratio (OR) = 1.74, 95% confidence interval (CI): 1.40–2.54) and thyroid nodules (OR = 3.33, 95%CI 1.32–8.42). In addition, subjects with deficient and excessive UIC were at the higher risk of TAI compared with those with adequate UIC (OR = 1.68, 95%CI: 1.19–2.60; OR = 1.52, 95%CI: 1.04–2.96, respectively). UIC was positively correlated with the prevalence rates of thyroid nodules (r = −0.44, P < 0.01) and TAI (r = −0.055, P < 0.01). On the contrary, UIC was negatively correlated with the risk of thyroid dysfunction (r = −0.24, P > 0.05). Conclusion: Adult inhabitants from Jiangxi province in the TIDE study were in the adequate iodine status. Excessive iodine status was noted as a risk factor for thyroid dysfunction and thyroid nodules. In addition, both iodine deficiency and excessive iodine were risk factors for TAI. [ABSTRACT FROM AUTHOR]

The continuous high-intensity and disorderly expansion of construction land in mountainous areas threatens city development; consequently, the scientific guidance of its sustainable development has become a research hotspot. This work aimed to develop a new theoretical framework for predicting land expansion. Based on DMSP/OLS-Landsat 7 data correction from 2000 to 2019, to ensure data reliability, this study quantitatively analysed the expansion law of land-use and land-cover (LULC) in Huayuan, a typical mountainous area in China. Based on the land expansion law, the patch-generating land use simulation (PLUS) model was used to predict various types of LULCs in different scenarios. The results showed that (1) the reliability of LULC under multi-source spatio-temporal data correction reached more than 0.97. (2) The expansion law of industrial and mining land, urban living land, and traffic land is sprawl, while rural living land is enclaved and the expansion direction and intensity are obviously different. (3) The scale of land expansion in the natural-oriented scenario was significantly higher than that in the humanism-oriented scenario, with a higher value of 199.33 hm2. This study expands the case study of land use analysis and prediction, and provides scientific guidance for different land expansion planning, which can avoid the mismatch and waste of land resources. Furthermore, it also deepens the exploration of LULC identification reliability method and enriches the theory of different land use prediction in mountainous areas. [ABSTRACT FROM AUTHOR]

GPS radio occultation (GPS-RO) data, especially the parameters of signal-to-noise ratio normalized standard deviation (SNRnstd) and S4, are widely used to measure the ionospheric sporadic E (Es) layer. However, the Es occurrence rates vary with the applied GPS-RO parameters. In view of this fact, we investigate the performances of the GPS-RO SNRnstd and S4 in the detection of Es occurrence rates by comparing them with ionosonde measurements around the globe during a five-year period from 2009 to 2013. The relation between SNRnstd maximum and S4 maximum is constructed firstly to set suitable thresholds. Then the previous thresholds (0.1 for SNRnstd and 0.3 for S4) and new threshold 0.2 for S4 are processed. The statistical results show Es occurrence rates by SNRnstd with threshold 0.1 and S4 with threshold 0.2 are comparable to that of ionosonde for foEs greater than or equal 3 MHz, while the corresponding result by S4 with threshold 0.3 is significantly underestimated. This suggests the established relation between SNRnstd maximum and S4 maximum is reliable and the difference between SNRnstd and S4 could be significantly reduced by selecting a suitable threshold. [ABSTRACT FROM AUTHOR]

Poly(L-lactide-co-ε-caprolactone) (PLCL) nanocomposites reinforced with graphene oxide modified by poly (L-lactic acid) (g-GO) were prepared by solution casting, where the graft ratio of PLLA to GO is about 11.7%. The results show that the g-GO possesses improved dispersion and interface interactions with the PLCL matrix, therefore, the final mechanical properties of nanocomposites are enhanced. Comparing with neat PLCL, the tensile strength and elongation at break of (1wt%)g-GO/PLCL are increased by 86.4% and 82.4%, respectively. Moreover, the g-GO/PLCL nanocomposite containing 1 wt% g-GO exhibits excellent thermal- induced and NIR light-induced shape memory effects and the shape recovery ratio is all up to 95%. The nanocomposites also have favorable antibacterial properties. The g-GO/PLCL nanocomposites with good NIR light-induced shape memory effect, antibacterial properties, biodegradability and biocompatibility have great potential for minimally invasive surgery. [ABSTRACT FROM AUTHOR]

Geohazards are a serious concern in mountainous areas, especially in China. Substantial efforts have been made to evaluate the geohazard susceptibility in different areas via quantitative analysis. However, such efforts have focused mainly on the spatial heterogeneity of disasters, ignoring both their spatial autocorrelation and the effects of human activities connected to rapid urban development. To address these limitations, we develop a spatial autocorrelation regression (SAR) modeling framework for geohazard susceptibility assessment using human and natural activity data from the typical mountainous Shennongjia area of China. Moreover, we compared different evaluation models using cross-validation and receiver operating characteristic (ROC) curves. The key findings of this work are as follows: (1) SAR is more suitable for geohazard susceptibility assessment compared with other models, as demonstrated by the ROC values of 0.829, 0.789, and 0.527; (2) the human activities of road construction, building construction, and agricultural activity make the highest contributions to geohazards in the area, at 42.78%, 27.84%, and 11.41%, respectively; and (3) there are three high-risk areas in the case area, revealing obvious spatial aggregation. The evidence reported here can be used to accurately identify the risk of geohazards, guide the government emergency departments in disaster prevention, and avoid risky areas to carry out follow-up urban construction. [ABSTRACT FROM AUTHOR]

This paper presents the findings from a thorough analysis of international technology diffusion (ITD) in artificial intelligence (AI) technologies. We construct a novel framework to explore the patterns of ITD in AI based on patent data published from 1970 to 2019. To this aim, we establish a nexus between technology innovation (TI) capacity and international technology diffusion (ITD) degree, and divide the countries/regions into three different groups—the leading, middle and backward. Considering the intersecting characteristic of AI technology, this paper examines the ITD patterns in the whole, single-field and intersecting-field AI technology areas. Empirical results show that: (1) Similar patterns are observed in the whole and single-field AI technology. ITD degree decreases significantly as TI capacity increases in leading countries, while it always remains high though the TI capacity improves in backward countries. Middle countries, however, show a transitional state between the two. (2) Compared to the whole AI and single-field AI technology, the pattern of ITD in intersecting-field AI technology is different. The number of nodes in the intersecting-field AI technology has decreased significantly, and the trend is more pronounced in middle and backward countries than in leading countries. These patterns imply that the technological innovation achievements of middle and backward countries will be first identified and utilized by leading countries, which will broaden the growing digital divide between countries and pose a more significant challenge to achieving technological catch-up in the future. [ABSTRACT FROM AUTHOR]

In this work, we design a silicon-on-insulator (SOI) sidewall grating with tunable wavelength, delay, and bandwidth through thermal tuning. Incorporating uniform sidewall corrugations and a linearly chirped rib waveguide, the thermo-optic effect imposed on chirped rib waveguide changes the effective refractive index, due to the resultant of the temperature gradient. Consequently, tunable wavelength, delay, and bandwidth in SOI sidewall grating are achieved. In the numerical simulations, the designed SOI grating is demonstrated with a tunable wavelength from 1 560.7 nm to 1 561.9 nm, a tunable delay from 0 to 38 ps, and a tunable bandwidth from 1 nm to 1.5 nm. [ABSTRACT FROM AUTHOR]

To get an accurate dimensional size/shape/spatial and assembly accuracy, flexible assembly tooling is developed and applied in aviation production, instead of traditional dedicated rigid tooling. Its configuration can be adjusted to fit different assembly environments and support/locate different components together in correct relative positions. For multiple aircraft components, the optimal design on flexible assembly tooling system, i.e., flexible locating method and motion stroke of different locating units, was studied in this paper. Firstly, to assemble the multiple components with a flexible method, the optional geometric features were defined and divided into several groups, with cluster analysis. Secondly, with two-stage progressive reasoning and the polychromatic set theory, the precise logical mapping relationship between product assembly/coordination requirements and detailed tooling locating methods was proposed. Thirdly, considering the constraints of assembly operation space, assembly constraints (such as assembly loads and locating freedom), product posture, and other specific assembly factors, a design procedure with quantitative analysis and containing eleven steps was proposed and modeled, and then solved with intelligent algorithm. Lastly, flexible design for assembling four different wing flap components was optimized to verify the methodology's feasibility. The flexible assembly system has a compact/simplified structure, and a sufficient assembly operation space. The layout scheme of the comprised units distributes by three rows, and parallel to each other. And the locating function of end locating effectors is highly integrated with a good flexibility degree. Combined with the practical design and assembly process, the motion stroke fits well with flexible assembly requirements, demonstrating a good locating/assembly performance. [ABSTRACT FROM AUTHOR]

As a key and core technology in aircraft manufacturing industry, assembly coordination technology is important to improve the competitiveness and manufacturing level. To get accurate dimensional size/shape/spatial position and coordination accuracy, according to characteristics of the working mode based on hard master tooling, working mode based on digital coordination model (DCM) is developed. Firstly, with the idea of digital twin, by analyzing the controlling method for coordination accuracy, a principle of the working mode based on DCM is proposed. The defined DCM is a process model that mirrors a practical assembly site, which consists of coordination element (CE), coordination relationship (CR), and control method for coordination accuracy (CMCA). It can replace hard master tooling as the only basis for the transfer process of dimension/shape/position in aircraft manufacturing. Secondly, the principle and detailed function process based on DCM in the whole aircraft manufacturing stage are presented. It is shown that the foundation of this mode is DCM, the focus of this mode is error transfer process in assembly, the direct analysis basis of this mode is measuring data, the core factor of this mode is dynamic feedback adjustment, and the ultimate goal is to control the consistency of accumulated error between assemblies. In contrast with the working mode based on hard master tooling, under the measuring field and virtual simulation/analysis environment, the function process of this mode is a dynamic closed loop comprising CEs/CRs that can be adjusted continually in real time with CMCA. Lastly, flexible assembling of four wing flap components is verified. Benefit results showed that the propagation of dimension/shape/position for products and flexible tooling can be completed under the working mode based on DCM. Furthermore, assembly accuracy and coordination accuracy can fit design requirements well, and the assembly efficiency with this new working mode is increased about 40%. [ABSTRACT FROM AUTHOR]

An increasing number of geological hazards threaten human life and property in mountainous areas, especially in China. Existing studies on the prevention of geological hazards mainly focus on natural factors and ignore the impact of human activities on geological hazards. This study aims to enrich our knowledge of the impact of human activities through a case study from the Shennongjia mountainous area, China. Spatial regression models were used to quantify the impact of different construction activities on geological hazards based on remote sensing images, local statistical data, land-use data and geological hazards distribution data. The Shennongjia case revealed the following: (1) The global Moran's I index of the distribution of geological hazards was 0.35, which showed obvious spatial autocorrelation characteristics. (2) From the multiple model comparison, the spatial lag model was more suitable for quantifying the impact of human activities on geological hazards than the least squares regression model and the spatial error model. (3) Road construction and building construction were the main causes of geological hazards, whereas agricultural activities and mining activities had only a limited effect. The evidence reported here could enable governments to constrain human activities and to reduce the geological hazards in mountainous areas across China and beyond. [ABSTRACT FROM AUTHOR]

A multiple-channel plasmonic filter based on metal-insulator-metal waveguide and fractal theory is proposed. The sandwiched insulator layer is constructed by a series of dielectrics with different refractive indices by following the fractal theory for the first time, to the best of our knowledge. In the designed plasmonic filter with orthogonal defect states, the number of channels can be adjusted through the arrangement of the insulator layer and each channel can be independently controlled by changing the refractive indices of coupling dielectrics in the insulator layer. In particular, a filter with three transmission channels has been designed. The characteristics of the transmission spectrum are investigated by using the finite-difference time-domain method. Numerical results indicate that this triple-channel plasmonic filter has high transmission efficiency greater than 0.51 and a narrow bandwidth less than 3.9 nm. Consequently, the proposed structure is capable of implementing compact multiple-channel filters for many specific applications, such as integrated devices or subsystems. [ABSTRACT FROM AUTHOR]

The mechanism of methylene blue (MB) oxidation initiated by hydroxyl radicals (·OH) in a gas-liquid multiphase plasma reactor was investigated. Direct current corona plasma was applied to produce ·OH. The effects of liquid solution pH and plasma-forming gas components (air, N, He, CO) were evaluated. The removal of MB exceeded 90 % after 3 h of treatment under an air atmosphere at neutral pH, and it was shown to be mainly through the function of ·OH. Further experiments demonstrated that ·OH was mainly produced through electron-molecule collision processes. The energy efficiency of the process was assessed to be as high as 3.8 × 10 mol/kWh when the removal of MB reached 95.7 %. This high value was due to the countless liquid droplets greatly increasing the contact surface area. The results using CO as the forming gas indicated that the carbonate in solution has a negative effect on the generation of ·OH. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to investigate whether the therapeutic activity of gemcitabine (GCB) in hepatocellular carcinoma (HCC) could be increased by the down-regulation of secretory clusterin (sCLU), a glycoprotein that is considered to play a cytoprotective role in the resistance to chemotherapy. Methods: The expression of sCLU was detected in HCC tumor tissues and cell lines. A cell viability and apoptosis assay were performed in parental HCC cells or the same cells transfected with sCLU shRNA and treated with or without GCB. The potential downstream pathways were investigated using the Human Apoptosis RT Profiler™ PCR Array. Results: The expression levels of sCLU in HCC tissues were significantly higher than in adjacent non-tumor liver tissues and were associated with the histological grade and transarterial chemoembolization. sCLU overexpression was also found in three HCC cell lines and hepatocytes. The depletion of sCLU synergistically increased GCB sensitivity in Bel7402 and SMMC7721 cells and induced cell apoptosis. Based on the PCR array analysis, sCLU depletion also resulted in the up-regulation of BNIP1, GADD45A, TNFRSF10A, and TRADD and down-regulation of AKT1 in Bel7402 and SMMC7721 cells compared with the parental controls. These results were further supported by a Western blot analysis, which showed increased GADD45a protein expression and the decreased expression of phosphorylated AKT. GADD45a overexpression also increased the sensitivity to GCB in the Bel7402 and SMMC7721 cells. Conclusion: Targeting sCLU may be a useful method to enhance the cytotoxic effect of GCB in hepatocellular carcinoma. [ABSTRACT FROM AUTHOR]

Chronic pain is a common neurological disease involving lasting, multifaceted maladaptations ranging from gene modulation to synaptic dysfunction and emotional disorders. Sustained pathological stimuli in many diseases alter the output activities of certain genes through epigenetic modifications, but it is unclear how epigenetic mechanisms operate in the development of chronic pain. We show here that in the rat brainstem nucleus raphe magnus, which is important for central mechanisms of chronic pain, persistent inflammatory and neuropathic pain epigenetically suppresses Gad2 (encoding glutamic acid decarboxylase 65 (GAD65)) transcription through histone deacetylase (HDAC)-mediated histone hypoacetylation, resulting in impaired ?-aminobutyric acid (GABA) synaptic inhibition. Gad2 knockout mice showed sensitized pain behavior and impaired GABA synaptic function in their brainstem neurons. In wild-type but not Gad2 knockout mice, HDAC inhibitors strongly increased GAD65 activity, restored GABA synaptic function and relieved sensitized pain behavior. These findings suggest GAD65 and HDACs as potential therapeutic targets in an epigenetic approach to the treatment of chronic pain. [ABSTRACT FROM AUTHOR]

Solid-liquid equilibrium of ternary system Cd, Na//Cl-HO at 298 K were studied by an isothermal solution saturation method. Experimental results indicate that there are three univariant curves AE, EF, and FB, two invariant points E, F, and three crystallization fields in the ternary system. The ternary system has one double salt NaCdCl · 3HO. The crystallization zones of equilibrium solid phases are CdCl · HO ( AEG field), NaCdCl · 3HO ( EFM field), and NaCl ( FBN field), respectively. The composition of the invariant point E is CdCl · HO and NaCdCl · 3HO of which content was 52.70 and 4.11%, respectively. The composition of the invariant point F is NaCdCl · 3HO and NaCl of which content was 27.92 and 14.95%, respectively. The density of solution in the ternary system show regular changes along with the increased cadmium concentration. The results indicated that CdCl · HO possessed the highest solubility among those three salts, which means a strong transfer of Cd ion and a high pollution risk of soil environment. And the solubility of NaCl would be restrained as the three salts existing together. [ABSTRACT FROM AUTHOR]

Acetylene hydrochlorination is a major industrial technology for manufacturing vinyl chloride monomer in regions with abundant coal resources; however, it is plagued by the use of mercury(II) chloride catalyst. The development of a nonmercury catalyst has been extensively explored. Herein, we report a N-doped carbon catalyst derived from ZIF-8 with both high activity and quite good stability. The acetylene conversion reached 92% and decreased slightly during a 200 h test at 220 °C and atmospheric pressure. Experimental studies and theoretical calculations indicate that C atoms adjacent to the pyridinic N are the active sites, and coke deposition covering pyridinic N is the main reason for catalyst deactivation. The performance of those N-doped carbons makes it possible for practical applications with further effort. Furthermore, the result also provides guidance for designing metal-free catalysts for similar reactions. [ABSTRACT FROM AUTHOR]