15 research outputs found

    Microwave Irradiation Enhances the Germination Rate of Tartary Buckwheat and Content of Some Compounds in Its Sprouts

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    Tartary buckwheat (Fagopyrum tataricum) seeds were irradiated with microwaves at various power levels of 200, 400, 600 and 800 W for 10 or 30 s. The irradiated grains were germinated for 3, 5, and 7 days and harvested. The germination rate of the tartary buckwheat seeds and contents of some compounds in the sprouts were investigated. The results showed that the exposure to 600 W microwaves for 10 s resulted in the highest final germination rate after 7 days of germination, which was 2 times that of the control. The exposure of seeds to 800 W for 30 s showed the lowest germination rate (approximately 10%), which decreased by 87% compared with the control (p<0.05). The exposure at 600 W for 30 s stimulated the total flavones content, reduced the sugar and soluble protein contents, and increased the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. The highest free amino acid content (11 mg/g) was observed in 5-day sprouts exposed to 800 W for 10 s. Moreover, the microwave treatment had a positive effect on the catalase (CAT) and superoxide dismutase (SOD) activity

    Porous highly fluorinated polyimide/polydopamine nanocomposite films with simultaneously enhanced toughness, UV-shielding and photostability for aerospace applications

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    Polydopamine (PDA), also known as artificial melanin, was adopted as ultraviolet absorbent to prepare a series of porous highly fluorinated polyimide/polydopamine (FPI/PDA) films by cyclodehydration via chemical and thermal imidization. The hydrogen bond and porous structure endowed the reinforced thermal, mechanical, UV-shielding and photostability. The initial decomposition and glass transition temperatures of FPI/PDA (1 wt %) film were as high as 461.5 °C and 341.5 °C, respectively beyond pure FPI by 54.1 °C and 26.0 °C. The stress-strain curves indicated that tensile strength and fracture elongation first increased and then decreased with the increase of PDA content, and reached the maximum at 0.5 wt % PDA content, which were 1.41 and 29.47 times of FPI, respectively. UV–vis transmittance spectra, curcumin photolysis and recyclability measurement confirmed the splendid UV-shielding properties with simultaneous excellent visible light transmittance and durability of porous FPI/PDA film. FTIR and AFM manifested its superior photostability with mild variation in carbonyl absorption peaks and surface roughness after 720 h UV irradiation. The above enhancement mechanisms included synergistic UV absorption of porous FPI and PDA, photothermal conversion in a stable FPI, and PDA's free radical trapping, promoting porous FPI/PDA film as an aerospace UV shielding material

    Crustal thickening in Gansu-Qinghai, lithospheric mantle subduction, and oblique, strike-slip controlled growth of the Tibet plateau

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    International audienceFieldwork complemented by SPOT image analysis throws light on current crustal shortening processes in the ranges of northeastern Tibet (Gansu and Qinghai provinces, China). The ongoing deformation of Late-Pleistocene bajada aprons in the forelands of the ranges involves folding, at various scales, and chiefly north-vergent, seismogenic thrusts. The most active thrusts usually break the ground many kilometres north of the range-fronts, along the northeast limbs of growing, asymmetric ramp-anticlines. Normal faulting at the apex of other growing anticlines, between the range fronts and the thrust breaks, implies slip on blind ramps connecting distinct active dĂ©collement levels that deepen southwards. The various patterns of uplift of the bajada surfaces can be used to constrain plausible links between contemporary thrusts downsection. Typically, the foreland thrusts and dĂ©collements appear to splay from master thrusts that plunge at least 15–20 km down beneath the high ranges. Plio-Quaternary anticlinal ridges rising to more than 3000 m a.s.l. expose Palaeozoic metamorphic basement in their core. In general, the geology and topography of the ranges and forelands imply that structural reliefs of the order of 5–10 km have accrued at rates of 1–2 mm yr−1 in approximately the last 5 Ma. From hill to range size, the elongated reliefs that result from such Late-Cenozoic, NE–SW shortening appear to follow a simple scaling law, with roughly constant length/width ratio, suggesting that they have grown self-similarly. The greatest mountain ranges, which are over 5.5 km high, tens of kilometres wide and hundreds of kilometres long may thus be interpreted to have formed as NW-trending ramp anticlines, at the scale of the middle–upper crust. The fairly regular, large-scale arrangement of those ranges, with parallel crests separated by piggy-back basins, the coevality of many parallel, south-dipping thrusts, and a change in the scaling ratio (from #5 to 8) for range widths greater than #30 km further suggests that they developed as a result of the northeastward migration of large thrust ramps above a broad dĂ©collement dipping SW at a shallow angle in the middle–lower crust. This, in turn, suggests that the 400–500 km-wide crustal wedge that forms the northeastern edge of the Tibet–Qinghai plateau shortens and thickens as a thickskinned accretionary prism decoupled from the stronger upper mantle underneath. Such a thickening process must have been coupled with propagation of the Altyn Tagh fault towards the ENE because most thrust traces merge northwestwards with active branches of this fault, after veering clockwise. This process appears to typify the manner in which the Tibet–Qinghai highlands have expanded their surface area in the Neogene. The present topography and structure imply that, during much of that period,

    Transcriptional inhibition of Hoxd4 expression by noncoding RNAs in human breast cancer cells

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    BACKGROUND: Small noncoding RNAs (ncRNAs), including short interfering RNAs (siRNAs) and microRNAs (miRNAs), can silence genes at the transcriptional, post-transcriptional or translational level [1,2]. RESULTS: Here, we show that microRNA-10a (miR-10a) targets a homologous DNA region in the promoter region of the hoxd4 gene and represses its expression at the transcriptional level. Mutational analysis of the miR-10a sequence revealed that the 3' end of the miRNA sequence is the most critical element for the silencing effect. MicroRNA-10a-induced transcriptional gene inhibition requires the presence of Dicer and Argonautes 1 and 3, and it is related to promoter associated noncoding RNAs. Bisulfite sequencing analysis showed that the reduced hoxd4 expression was accompanied by de novo DNA methylation at the hoxd4 promoter. We further demonstrated that trimethylation of histone 3 lysine 27 (H3K27me3) is involved in the miR-10a-induced hoxd4 transcriptional gene silence. CONCLUSION: In conclusion, our results demonstrate that miR-10a can regulate human gene expression in a transcriptional manner, and indicate that endogenous small noncoding RNA-induced control of transcription may be a potential system for expressional regulation in human breast cancer cells

    Detection of Common Anatomical Landmarks and Vertical Trajectories for Freehand Pedicle Screw Placement

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    Objective It is clinically important for pedicle screws to be placed quickly and accurately. Misplacement of pedicle screws results in various complications. However, the incidence of complications varies greatly due to the different professional titles of physicians and surgical experience. Therefore, physicians must minimize pedicle screw dislocation. This study aims to compare the three nail placement methods in this study, and explore which method is the best for determining the anatomical landmarks and vertical trajectories. Methods This study involved 70 patients with moderate idiopathic scoliosis who had undergone deformity correction surgery between 2018 and 2021. Two spine surgeons used three techniques (preoperative computed tomography scan [CTS], visual inspection‐X‐freehand [XFH], and intraoperative detection [ID] of anatomical landmarks) to locate pedicle screws. The techniques used include visual inspection for 287 screws in 21 patients, preoperative planning for 346 screws in 26 patients, and intraoperative probing for 309 screws in 23 patients. Observers assessed screw conditions based on intraoperative CT scans (Grade A, B, C, D). Results There were no significant differences between the three groups in terms of age, sex, and degree of deformity. We found that 68.64% of screws in the XFH group, 67.63% in the CTS group, and 77.99% in the ID group were placed within the pedicle margins (grade A). On the other hand, 6.27% of screws in the XFH group, 4.33% in the CTS group, and 6.15% in the ID group were considered misplaced (grades C and D). The results show that the total amount of upper thoracic pedicle screws was fewer, meanwhile their placement accuracy was lower. The three methods used in this study had similar accuracy in intermediate physicians (P > 0.05). Compared with intermediate physicians, the placement accuracy of three techniques in senior physicians was higher. The intraoperative detection group was better than the other two groups in the good rate and accuracy of nail placement (P < 0.05). Conclusion Intraoperative common anatomical landmarks and vertical trajectories were beneficial to patients with moderate idiopathic scoliosis undergoing surgery. It is an optimal method for clinical application

    Active thrusting and folding in the Qilian Shan, and decoupling between upper crust and mantle in northeastern Tibet

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    Fieldwork south of the city of Gaotai (Gansu province, China) shows that active shortening of surface sediments in the foothills of the Yumu Shan, a large fore-mountain of the Qilian Shan, at the northeastern edge of Tibet, involves both overthrusting and flexural-slip folding. North of this mountain, we found and mapped a prominent north-facing thrust scarp that offsets a Holocene fan sloping gently (3.4°) to the north. Part of this scarp appears to be related to the M ≈ 7.5, 180 A.D. earthquake that may have led to the demise of the Han Dynasty city of Luo Tuo Chen, in the Hexi corridor. A set of 10, 100–150 m long profiles measured across this scarp, 3.2 m high on the average, can be made to fit the diffusion-degraded morphology of a surface break related to the 180 A.D. event using a value of about 3.3 m^2/10^3 yr for the mass diffusivity ϰ of fanglomerates in this part of Gansu province. Smaller mountain-facing scarps on a terrace-capped foothill result from bedding slip concurrent with active folding of underlying, steeply northdipping, Plioquaternary sandstone and conglomerate beds. Holocene uplift rates along the Yumu Shan, which is only one of the Qilian Shan ranges, are estimated to be between 0.4 and 1.9 mm/yr, which implies that much of the mountain formed in the Quaternary. The periclinal structure of the Plioquaternary envelope under which the Paleozoic core of the Yumu Shan plunges towards the west suggests that the whole 3200 m high mountain is a basement ramp anticline. Mountains striking parallel to the Yumu Shan, with similar structure and comparable or greater sizes north and south of the Hexi corridor probably also correspond to recent, crustal ramp anticlines. This implies that the wide, mountainous upper crustal wedge making the northeastern edge of the Tibet-Qinghai plateau is detached from the underlying lower crust and upper mantle

    Infrared and Raman Spectroscopic Characterization of Structural Changes in Albumin, Globulin, Glutelin, and Prolamin during Rice Aging

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    Structural changes in albumin, globulin, glutelin, and prolamin from fresh and aged rice were characterized in this study. Infrared and Raman spectroscopies revealed changes in interactions between protein and starch, and the occurrence of structural changes involving secondary and tertiary structures of protein induced by rice aging. The α-helical structure was reduced, and aliphatic amino-acid side chains became more buried in albumin after rice aging. Oxidation of the sulfhydryl group in globulin was evident. The unordered coil in glutelin decreased, and a characteristic frequency of the free sulfhydryl group appeared. The antiparallel ÎČ-sheet in prolamin increased, the conformation of disulfide bonds changed, and tyrosine residues became exposed to a polar environment. The association between globulin and starch strengthened, whereas that between glutelin and starch diminished. These differences in structure and interactions with starch might be responsible for the dissimilar pasting properties between fresh and aged rice
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