Search

Receptor tyrosine kinases (RTKs) control the basic activities of cells including proliferation, cell cycle, apoptosis, metabolism and so on. Accordingly, abnormal activation caused by mutations of RTKs plays an important part in the formation and development of tumor. For the past few years, the receptor tyrosine kinase inhibitors (rTKI) developed for RTKs have progressed rapidly and achieved good results in clinical treatment in various tumor types, such as chronic myelogenous leukemia, non-small cell lung cancer, breast cancer and so on. As for acute myeloid leukemia (AML), approval and clinical application of inhibitors against Fms-like tyrosine kinase 3 (FLT3) significantly improve prognosis in patients with FLT3 mutations, which is vital for the treatment of AML. The clinical application of rTKI to AML is summarized in this review, providing a reference for the treatment of AML. [ABSTRACT FROM AUTHOR]

Objective: To systematically review the clinical efficacy and safety of Qingfei Paidu Decoction in the treatment of novel coronavirus pneumonia (COVID-19) . Methods: Databases such as CNKI, Wanfang, VIP, Pubmed, Embase, and Cochrane Library were searched by computer until April 20, 2022, and the clinical efficacy studies of Qingfei Paidu Decoction combined with western medicine in the treatment of COVID-19 were screened out. The Cochrane risk of bias assessment tool was used to assess the risk and quality of the included studies, and relevant data were extracted. Meta analysis was performed using State17.0 software, and Begg's test analyzed publication bias. Results: A total of 602 patients were included in 6 clinical efficacy studies, of which 295 patients in the experimental group were treated with Qingfei Paidu Decoction combined with western medicine, and 307 patients in the control group were treated with western medicine alone. Meta-analysis results showed that the experimental group improved the clinical efficacy [RR=1.17, 95%CI (1.09, 1.26), P<0.000 1], and the CT improvement [RR=1.20, 95% CI (1.10, 1.30), P<0.000 1], reduced adverse reactions [RR=0.73, 95%CI (0.60, 0.90), P=0.002], shortened the time to negative nucleic acid [WMD=-6.56, 95%CI (-10.37, -2.75), P=0.000 7], length of hospital stay [WMD=-4.75, 95%CI (-6.26, -3.25), P<0.000 01] were better than the control group. Conclusion: Qingfei Paidu Decoction combined with conventional western medicine therapy can effectively improve the clinical symptoms of COVID-19, with certain efficacy and safety, while a large number of high-quality studies are still needed to confirm the efficacy. [ABSTRACT FROM AUTHOR]

Adiabatic shear is known to be a precursor to the failure of metals processed at high strain rate. The present study focuses on the adiabatic shear failure characteristic of TA2 titanium alloy under dynamic compression. The dynamic stress-strain behavior is tested by split Hopkinson pressure bar (SHPB), and adiabatic shear bands ( ASBs) are investigated by means of optical microscopy. The metallographic analysis reveals that the ASBs pattern in specimen is symmetrical bi-conical. Furthermore, a comprehensive finite element analysis of shear localization of the deformed cylindrical specimens is carried out. The numerical simulations are in agreement with the experimental results, and the frictional force between the specimen and the Hopkinson bars significantly affects the evolution of shear localization. [ABSTRACT FROM AUTHOR]

Objective To set parameters for accurate cell counting by flow cytometer. Method By setting forward scatter (FSC), side scatter (SSC) and speed, we programmed the enumeration of GLC, and compared the results between flow cytometer method and blood counting plate method. Result There was no significant difference in the concentration of GLC between the blood counting plate method and flow cytometer method of the appropriate speed (P>0.05). Conclusions CyFlow Space flow cytometer is able to quickly and accurately count cultured cell lines, flow cytometer method can be recommend to be applied in large scale experiments for cell counting. [ABSTRACT FROM AUTHOR]

Objective To investigate the effect and molecular mechanisms of Notch signaling in the protection of neuropeptide substance P (SP) in hyperoxia-exposed alveolar type II epithelial cells (AECII). Methods AECII were isolated from the lung of 19-day rat fetus and then cultured in six-well plates. The cells were randomly divided into air group, hyperoxia group, hyperoxia + SP group, and hyperoxia + SP + antagonist group. Air group was exposed to 21% oxygen and hyperoxia group was exposed to 95% oxygen for 24 hours, respectively. SP was added into hyperoxia + SP group before oxygen exposure, while SP and its receptor antagonist (L703.606) were added into hyperoxia +SP + antagonist group simultaneously before oxygen exposure; then both groups were exposed to 95% oxygen for 24 hours. Flow cytometry and MTT colorimetric assay were used to detect the ability of cell proliferation; the intracellular superoxide anion level was detected by SpectraMax M5/M5e and confocal microscopy; the mRNA and protein expressions of Notch1 and Notch3 were assessed by QPCR and Western blot analysis, respectively. Results Compared with those in air group, the apoptosis rate and the intracellular superoxide anion concentration were significantly increased, while the proliferation rate of cells was significantly decreased in hyperoxia group (P<0.01). In contrast, the apoptosis rate and the intracellular superoxide anion concentration were lower and the cell proliferation rate were higher in hyperoxia SP group than in hyperoxia group (P<0.01). Hyperoxia exposure resulted in significantly decreased expression of Notch1 and increased expression of Notch3 (P<0.01), while SP treatment reversed the above results significantly (P<0.01). These parameters did not differ significantly between hyperoxia group and hyperoxia + SP + L703.606 group. Conclusion SP can reduce the hyperoxia-induced AEC damage and death and promote cell proliferation, which is associated with the activation of Notch signal transduction pathway. [ABSTRACT FROM AUTHOR]

Based on measured velocities in conical vortices by flow visualization, a simplified two-dimensional vortex model was established by adding transitional region between the vortex core and the potential flow region of the Rankine vortex. Through this flow model, a relationship between the flow above the vortices, the curvature radius of flow streamlines in the vortices and the suctions beneath vortex cores was given. The flow model indicats that the larger the curvature of flow streamlines and the faster the vortex spins, the greater the intensity of vortex is. The effect of rational velocity on intensity of vortices is more obvious. Through measured velocities by flow visualization and parameters of vortices, the intensities of conical vortices on a large-span fiat roof under different wind directions were provided. The quasi-steady theory was corrected by including the effect of vortices. With this two-dimensional vortex model and the corrected quasi-steady theory, mean and peak suctions beneath cores of conical vortices can be predicted, which were verified by measured pressures on a larger-scale model of the large-span fiat roof. [ABSTRACT FROM AUTHOR]

PN junction with p-Si / n-Ga2O3 structure was developed by metal organic chemical vapor deposition (MOCVD) technology on p-type Si (111) substrate. The crystal structure, surface morphology and surface roughness were measured by X-ray diffractometer and atomic force microscope. Then Ti / Au electrodes on these samples were developed by magnet sputtering and evaporation for testing the PN junction characteristics such as I-V curve chart, threshold voltage, on-off current ratio, reverse saturation current, ideal factor, and the barrier height at zero bias voltage. The regulation of PN junction characteristics with growing parameters such as doping concentration and film thickness was studied, and the reasons were given. The crystal quality of β-Ga2O3 thin film and the characteristics of the devices were improved by two-step growing method. A set of PN junction samples were fabricated at three different temperatures when the buffer was developed. Finally, the best conditions of fabricating the PN junction devices was found, and the lattice mismatch and thermal mismatch between Si substrate and β-Ga2O3 thin film were reduced. A high quality n-type β-Ga2O3 thin film with surface roughness of 4. 21 nm and a PN junction with low ideal factor of 42. 1 was obtained. [ABSTRACT FROM AUTHOR]

Walnut cake and walnut meal are the by-products of walnuts after oil extraction. Walnut cake and meal are rich in nutrients such as protein and vitamins, but are high in dry matter and crude fiber. Walnut cake and meal have the advantages of large yield and low price, which can be used as a substitute for conventional protein feed in animal production, and can decrease the fodder in the premix of corresponding dosage of the trace elements and vitamins. The paper mainly reviews the nutritional value of walnut cake and walnut meal, the production process and their applications in the animal production, to provide a reference for the rational application of walnut cake and walnut meal in animal production. [ABSTRACT FROM AUTHOR]

Chitosan is a natural adsorption material with abundant sources, which is non-toxic and harmless and has a good adsorption effect on Cr (VI) in sewage. This paper introduces the existence form of Cr (VI) in aqueous solution, analyzes the adsorption mechanism of Cr (VI) by chitosan, and summarizes the research progress of chemical modification and composite modification of chitosan. The structure, active functional groups, adsorption principle and application of crosslinked modified chitosan, grafted modified chitosan, organic material composite modified chitosan, magnetic material modified chitosan, and composite carrier material modified chitosan were introduced in detail. Finally, the research direction of new material development, preparation process optimization and application expansion of modified chitosan were prospected. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) nanoporous copper current collector with bimodel pore size distribution was fabricated by dealloying of Al-35Cu alloy, and the three-dimensional interlayer-shaped nanoporous Cu/Cu6Sn5/Sn composite electrode was obtained further by chemical deposition of Sn on the surface of 3D nanoporous copper, in which Cu6Sn5 transition layer could be formed via quick reaction between Sn and Cu. Subsequently, the electrode was characterized by electrochemical performance testing. The results showed that the initial discharge specific capacity was 2. 53 mAh/cm² and the charge specific capacity was 0. 43 mAh/cm² at a current density of 0. 1 mA/cm². After 300-week cycles, the discharge specific capacity was still 0.159 mAh/cm², the charging specific capacity was 0. 157 mAh/cm², and the capacity retention rate was 36.5%, which indicated that the electrode had excellent electrochemical performance and had potential application prospects in the next generation high performance lithium ion battery. [ABSTRACT FROM AUTHOR]

Because high moisture content of the new-harvested corn stalks in northern China, drying process is long under natural conditions in which limit instantaneous harvesting and bundling. Fracturing and laceration on corn stalks need to be adjusted for rapid drying of corn stalks and to overcome bundle below. In order to design corn stalk adjusting material device, two single factor experiments were designed according to loading forms including single-point direct pressure and three-point bending in this study. Each experiment included four levels as: internode and short axis, internode and long axis, node and short axis and node and long axis. Impacts of loading forms (single-point direct pressure and three-point bending), loading positions (internode and node) and loading directions (long axis and short axis) on the cracks, load and power consumption of corn stalks with the same moisture content were investigated based on single factor experiment design scheme during compression process. The results indicated that four main cracks were produced on the rind of corn stalks under two loading forms on the axial during the compression process. Four main cracks of each corn stalks showed up, down, left and right symmetrical distribution, a number of small cracks were also produced. The main cracks gradually extended with the increasing of the displacements. When the displacements reached 18 mm for the internode compression samples, the main cracks extended to the vicinity of the node, and continuously reached to compression. The main cracks then stopped expanding due to the constraints of the node. The main cracks extended to the entire length of the sample for the node compression samples, the depth of all cracks were equal to the epidermis thickness of the sample. This study showed that length and depth of the main cracks of two loading forms were the same, so the best adjusting ending displacement was set to 18 mm. With the same loading positions and loading directions, the displacements of main cracks produced by three-point bending and single-point direct pressure were similar, but the load and power consumption of two loading forms were different. Load and power consumption of three-point bending were lower than single-point direct pressure. With the same loading positions,loading directions and the displacements, load and power consumption of two loading forms from big to small were node and short axis, node and long axis, internode and short axis and internode and long axis. Load and power consumption of three-point bending were lower than single-point direct pressure. In the initial stage of compression, there was no significant difference in the average value of load and power consumption between single-point direct pressure and three-point bending. With increasing the displacements, the difference of load and power consumption between single-point direct pressure and three-point bending was gradually expanded. When the displacement reached the best adjusting ending point (18 mm), the average value of load of three-point bending significantly reduced about 55.5% more than single-point direct pressure (α=0.05). The average value of power consumption of three-point bending was reduced about 25.5% more than single-point direct pressure (α=0.05). These results provided the basis for designing corn stalk harvesting and adjusting device. [ABSTRACT FROM AUTHOR]

As key parts of a corn and wheat combine harvester, the threshing cylinder is mainly processed with the method of welding. The processing quality of threshing cylinders, including cylindricity and verticality of outer radial discs fixed outside of threshing cylinders, is hard to guarantee. The major problems that the threshing cylinder end faces are radial run-out, which have seriously restricted the effect of threshing and selecting corn or wheat from millet straw. Thus, without online diagnosis method and system, the threshing cylinder of corn and wheat combine harvester will get poor quality. In this paper, the welding quality online detection method based on laser sensors was studied, and the online detection system of cylinder roundness and outer radial disc verticality during the welding was developed, including the threshing cylinder rotation driving system, laser sensor distance detection system, sliding guide rail system and data acquisition and display system. As to cylindricity detection, sliding guide rail that was parallel to the threshing cylinder axis was fixed on the welding platform, a laser distance detection sensor was fixed on the sliding guide rail, and a servo motor was connected to the threshing cylinder axis. While detecting, the threshing cylinder was driven to rotate, and at the same time, the laser sensor was driven to move along the sliding guide rail; and the vertical distance from the sensor to the threshing cylinder was detected, which was collected in real time by the computer. According to the threshing cylinder rotation data and laser sensor sliding track data, the threshing cylinder shape and cylindricity were calculated. As to the inspection of outer radial disc verticality, vertical sliding guide was fixed to the parallel sliding guide rail that was perpendicular to the sliding rail. Install laser sensor on the vertical sliding guide rail and keep the laser beam parallel to threshing cylinder axis. When the threshing cylinder was driven by the motor to rotate, the distance from the laser sensor to the outer radial disc was measured by the laser sensor, and the verticality of the outer radial disc was calculated by the computer. According to the method mentioned above, the online test platform was designed, and online detection was realized through data processing. Experiments were done and data was analyzed, including comparing the accuracy of the online detection system in this article and Cylindricity Measuring Instrument Talyrond130 (Taylor Hobson, England) and Laser verticality measuring instrument YHL-800 (ACROBEAM Co. Ltd, Xi'an, China), and the relative errors of duplicate tests were done by the online detection system. Results showed that, compared with Cylindricity Measuring Instrument Talyrond130, whose taper error was 0.00025 μm/mm, the absolute error of cylinder roundness detection was 0.059 mm; and compared with Laser verticality measuring instrument YHL-800, whose accuracy was 1/20 000 mm, the absolute error of outer radial disc perpendicularity detection was 0.123 mm. After 6 duplicate tests, the maximum relative error of cylindricity testing was 2.17%, the standard deviation was 0.021 mm, and the maximum relative error of perpendicularity detection was 1.93%, and the standard deviation was 0.011mm, which met the needs of the online detection of the threshing cylinder welding quality, and the efficiency of online detection system was 20 times that of traditional method. The development of the system can ensure the welding quality of large-scale harvester threshing cylinder. [ABSTRACT FROM AUTHOR]

As key parts of a corn and wheat combine harvester, the threshing cylinder is mainly processed with the method of welding. The processing quality of threshing cylinders, including cylindricity and verticality of outer radial discs fixed outside of threshing cylinders, is hard to guarantee. The major problems that the threshing cylinder end faces are radial run-out, which have seriously restricted the effect of threshing and selecting corn or wheat from millet straw. Thus, without online diagnosis method and system, the threshing cylinder of corn and wheat combine harvester will get poor quality. In this paper, the welding quality online detection method based on laser sensors was studied, and the online detection system of cylinder roundness and outer radial disc verticality during the welding was developed, including the threshing cylinder rotation driving system, laser sensor distance detection system, sliding guide rail system and data acquisition and display system. As to cylindricity detection, sliding guide rail that was parallel to the threshing cylinder axis was fixed on the welding platform, a laser distance detection sensor was fixed on the sliding guide rail, and a servo motor was connected to the threshing cylinder axis. While detecting, the threshing cylinder was driven to rotate, and at the same time, the laser sensor was driven to move along the sliding guide rail; and the vertical distance from the sensor to the threshing cylinder was detected, which was collected in real time by the computer. According to the threshing cylinder rotation data and laser sensor sliding track data, the threshing cylinder shape and cylindricity were calculated. As to the inspection of outer radial disc verticality, vertical sliding guide was fixed to the parallel sliding guide rail that was perpendicular to the sliding rail. Install laser sensor on the vertical sliding guide rail and keep the laser beam parallel to threshing cylinder axis. When the threshing cylinder was driven by the motor to rotate, the distance from the laser sensor to the outer radial disc was measured by the laser sensor, and the verticality of the outer radial disc was calculated by the computer. According to the method mentioned above, the online test platform was designed, and online detection was realized through data processing. Experiments were done and data was analyzed, including comparing the accuracy of the online detection system in this article and Cylindricity Measuring Instrument Talyrond130 (Taylor Hobson, England) and Laser verticality measuring instrument YHL-800 (ACROBEAM Co. Ltd, Xi'an, China), and the relative errors of duplicate tests were done by the online detection system. Results showed that, compared with Cylindricity Measuring Instrument Talyrond130, whose taper error was 0.00025 µm/mm, the absolute error of cylinder roundness detection was 0.059 mm; and compared with Laser verticality measuring instrument YHL-800, whose accuracy was 1/20 000 mm, the absolute error of outer radial disc perpendicularity detection was 0.123 mm. After 6 duplicate tests, the maximum relative error of cylindricity testing was 2.17%, the standard deviation was 0.021 mm, and the maximum relative error of perpendicularity detection was 1.93%, and the standard deviation was 0.011mm, which met the needs of the online detection of the threshing cylinder welding quality, and the efficiency of online detection system was 20 times that of traditional method. The development of the system can ensure the welding quality of large-scale harvester threshing cylinder. [ABSTRACT FROM AUTHOR]