Twinning-assisted static recrystallization and texture evolution in a Mg-Gd-Y-Zr alloy

The formability and mechanical properties of magnesium (Mg) alloys are strongly related to the crystallographic basal texture. Twins play critical roles in adjusting crystallographic orientation of grains during both deformation and annealing treatment via deformation twinning and twinning-assisted recrystallization. In this study, cold rolling and subsequent annealing were conducted on a Mg-5.9Gd-3.3Y-0.5Zr alloy to investigate the recrystallization behavior and texture evolution. Electron backscatter diffraction and transmission electron microscopy techniques were applied to characterize the nucleation of recrystallized grains, especially the twinning-assisted recrystallization, at multi-scales. The results indicated that a large number of {10-12}, {10-11} twins and {10-11} - {10-12} double twins were introduced after cold rolling. The {10-11} - {10-12} double twins, double twin - grain boundary intersections and dense twin-twin intersections acted as the preferential nucleation sites for recrystallization during annealing treatment, while the coarse and parallel {10-12} twins were unfavorable for the nucleation of recrystallized grains. Although {10-12} tension twins are the most common twins in Mg alloys, the interface of this type of twin has strong mobility and is easy to expand. Therefore, it is generally difficult for a single {10-12} twin to recrystallize. However, the {10-11} compression twins and {10-11} - {10-12} double twins are generally difficult to expand and can store high deformation energy, so they are conducive to becoming nucleation sites for recrystallization. During the recrystallization process, the texture type (basal texture) of the cold rolled sample remained unchanged, but the overall texture intensity was significantly reduced due to the dispersion of grain orientations brought by new grains generated by twinning recrystallization

Breaking Glucose Transporter 1/Pyruvate Kinase M2 Glycolytic Loop Is Required for Cantharidin Inhibition of Metastasis in Highly Metastatic Breast Cancer

Aerobic glycolysis plays a decisive role in cancer growth. However, its role in cancer metastasis was rarely understood. Cantharidin a natural compound from an arthropod insect cantharis exerts potent anticancer activity. Here we found cantharidin possesses significant anti-metastatic activity on breast cancer dependent on inhibition of aerobic glycolysis. Cantharidin indicates significant inhibition on migration and invasion of breast cancer cells, angiogenesis in vitro, and inhibits breast cancer cells metastasizing to liver and lung in vivo. Subsequent results revealed that cantharidin decreases the extracellular acidification rates (ECAR) but increases the oxygen consumption rates (OCR) in high metastatic cells, leading to suppression of aerobic glycolysis. This was considered to be due to inhibiting the activity of pyruvate kinase (PK) and further blocking pyruvate kinase M2 (PKM2) translocation in nucleus. Fructose-1,6-bisphosphate (FBP) and L-cysteine can significantly reverse cantharidin inhibition on breast cancer cell migration, invasion, and PKM2 translocation. Furthermore, glucose transporter 1 (GLUT1) forming a metabolic loop with PKM2 is downregulated, as well as epidermal growth factor receptor (EGFR), the regulator of the glycolytic loop. Totally, cantharidin inhibits the PKM2 nuclear translocation and breaks GLUT1/PKM2 glycolytic loop, resulting in aerobic glycolysis transformation to oxidation and subsequent reversing the metastases in breast cancer. Based on inhibiting multi signals mediated aerobic glycolysis, cantharidin could be prospectively used for prevention of metastasis in breast cancer patients

Brown Carbon Aerosol in Urban Xi’an, Northwest China: TheComposition and Light Absorption Properties

Light-absorbing organic carbon (i.e., brown carbon or BrC) in the atmospheric aerosol has significant contribution to light absorption and radiative forcing. However, the link between BrC optical properties and chemical composition remains poorly constrained. In this study, we combine spectrophotometric measurements and chemical analyses of BrC samples collected from July 2008 to June 2009 in urban Xi'an, Northwest China. Elevated BrC was observed in winter (5 times higher than in summer), largely due to increased emissions from wintertime domestic biomass burning. The light absorption coefficient of methanol-soluble BrC at 365 nm (on average approximately twice that of water-soluble BrC) was found to correlate strongly with both parent polycyclic aromatic hydrocarbons (parent-PAHs, 27 species) and their carbonyl oxygenated derivatives (carbonyl-OPAHs, 15 species) in all seasons (r(2) > 0.61). These measured parent-PAHs and carbonyl-OPAHs account for on average similar to 1.7% of the overall absorption of methanol-soluble BrC, about 5 times higher than their mass fraction in total organic carbon (OC, similar to 0.35%). The fractional solar absorption by BrC relative to element carbon (EC) in the ultraviolet range (300-400 nm) is significant during winter (42 +/- 18% for water-soluble BrC and 76 +/- 29% for methanol-soluble BrC), which may greatly affect the radiative balance and tropospheric photochemistry and therefore the climate and air quality

Role of Fractalkine/CX3CR1 Interaction in Light-Induced Photoreceptor Degeneration through Regulating Retinal Microglial Activation and Migration

Background: Excessive exposure to light enhances the progression and severity of some human retinal degenerative diseases. While retinal microglia are likely to be important in neuron damage associated with these diseases, the relationship between photoreceptor damage and microglial activation remains poorly understood. Some recent studies have indicated that the chemokine fractalkine is involved in the pathogenesis of many neurodegenerative diseases. The present study was performed to investigate the cross-talk between injured photoreceptors and activated retinal microglia, focusing on the role of fractalkine and its receptor CX3CR1 in light-induced photoreceptor degeneration. Methodology/Principal Findings: Both in vivo and in vitro experiments were involved in the research. In vivo, Sprague– Dawley rats were exposed to blue light for 24 hours. In vitro, the co-culture of primary retinal microglia and a photoreceptor cell line (661W cell) was exposed to blue light for five hours. Some cultures were pretreated by the addition of anti-CX3CR1 neutralizing antibody or recombinant fractalkine. Expression of fractalkine/CX3CR1 and inflammatory cytokines was detected by immunofluorescence, real-time PCR, Western immunoblot analysis, and ELISA assay. TUNEL method was used to detect cell apoptosis. In addition, chemotaxis assay was performed to evaluate the impact of soluble fractalkine on microglial migration. Our results showed that the expression of fractalkine that was significantly upregulated after exposure to light, located mainly at the photoreceptors. The extent of photoreceptor degeneration and microglial migratio

Three-Stage Pavement Crack Localization and Segmentation Algorithm Based on Digital Image Processing and Deep Learning Techniques

The image of expressway asphalt pavement crack disease obtained by a three-dimensional line scan laser is easily affected by external factors such as uneven illumination distribution, environmental noise, occlusion shadow, and foreign bodies on the pavement. To locate and extract cracks accurately and efficiently, this article proposes a three-stage asphalt pavement crack location and segmentation method based on traditional digital image processing technology and deep learning methods. In the first stage of this method, the guided filtering and Retinex methods are used to preprocess the asphalt pavement crack image. The processed image removes redundant noise information and improves the brightness. At the information entropy level, it is 63% higher than the unpreprocessed image. In the second stage, the newly proposed YOLO-SAMT target detection model is used to locate the crack diseases in asphalt pavement. The model is 5.42 percentage points higher than the original YOLOv7 model on [email protected], which enhances the recognition and location ability of crack diseases and reduces the calculation amount for the extraction of crack contour in the next stage. In the third stage, the improved k-means clustering algorithm is used to extract cracks. Compared with the traditional k-means clustering algorithm, this method improves the accuracy by 7.34 percentage points, the true rate by 6.57 percentage points, and the false positive rate by 18.32 percentage points to better extract the crack contour. To sum up, the method proposed in this article improves the quality of the pavement disease image, enhances the ability to identify and locate cracks, reduces the amount of calculation, improves the accuracy of crack contour extraction, and provides a new solution for highway crack inspection

Preparation and Anticorrosive Property of Soluble Aniline Tetramer

Soluble aniline tetramer (AT) was successfully prepared by chemical oxidation method. Fourier transform infrared spectroscopy (FTIR) and ultraviolet-visible spectroscopy (UV-vis) were used to characterize its structure. The redox behavior of AT was identified through the electrochemical cyclic voltammetry studies. Then, the epoxy coating was prepared by using AT as inhibitor. Its anticorrosive property was evaluated by salt solution resistance test, polarization curve, and electrochemical impedance spectroscopy (EIS). Salt solution resistance test, polarization curves, and EIS measurements indicate that the obtained epoxy anticorrosive coating, containing 1.0% AT, exhibits remarkably enhanced corrosion protection properties on Q235 steel electrodes as compared to pure epoxy anticorrosive coating without AT. The significantly improved anticorrosion performance may be owing to the redox behavior of the AT, adsorption and inhibition effect of AT on Q235 steel surface, as well as synergistic curing effect by AT and polyamide

The role of mass spectrometry for radioactive contamination assessment after the Fukushima nuclear accident

The Fukushima nuclear accident caused the release of large amounts of radionuclides into the environment. After the accident, radioactive contamination assessment in the environmental samples is essential for radiation dose estimation and radioactive remediation. Mass spectrometry characterized by high sensitivity, low detection limit, short measuring time, high sample throughput, and the capability to obtain atom ratios is a promising technique for the analysis of the accident released long-lived radionuclides. This review describes the developed analytical methods based on mass spectrometric techniques for the determination of radionuclides (Pu isotopes, U isotopes, radiocesium, radioiodine, radiostrontium etc.) with regards to Fukushima samples. The real applications of mass spectrometric techniques for radioactive source identification, radiation protection and geochemical tracing are discussed to highlight the importance of mass spectrometric techniques in radioactive contamination assessment after the accident. Future research perspectives of mass spectrometric techniques for the analysis of radionuclides with application to Fukushima samples are briefly outlined

First study of 237Np in Chinese soils: source, distribution and mobility in comparison with plutonium isotopes

In this study, the distribution and migration of 237Np and 239+240Pu in soils in the vicinity (<5 km) of Qinshan and Tianwan Nuclear Power Plants in China were studied. The 237Np and 239+240Pu concentrations in surface soils showed large spatial inhomogeneity. A remarkable 239+240Pu activity concentration (4.783 mBq/g) was observed in a surface soil near Qinshan NPP and stands for the ever reported highest value in the Chinese soils. The inventories of 239+240Pu in two Qinshan and Tianwan soil cores were estimated to be 128.8 Bq/m2 and 121.0 Bq/m2, respectively; while the 237Np inventories were 0.039 Bq/m2 and 0.035 Bq/m2 at these sites, respectively. The 240Pu/239Pu atom ratios in these soils indicated that the global fallout is the main source of Pu in these regions. However, the non-isotopic 237Np/239Pu atom ratio is not a sensitive and indicator for source identification. Furthermore, we conducted pilot study on the migration behaviors of 237Np and 239+240Pu in soil core at Qinshan site with the Convection-Dispersion Equation (CDE) model. The obtained apparent dispersion coefficients of 237Np (2.82±2.06 cm2/y) was 5 times higher than that of 239+240Pu (0.57±0.16 cm2/y), proving 237Np has stronger migration mobility than Pu isotopes. Finally, we predicted that with the increase of migration time, both 237Np and 239+240Pu activity concentration in the soil will gradually become homogeneous among different soil layers due to the dominant dispersion effects. This work is the first study on the distribution and migration of global fallout 237Np in Chinese soils