A novel FeNi coating with refined grain size and alternated distribution of element content was designed via laser-assisted electrochemical deposition. The formation of this microstructure is ...attributed to a specific laser scanning strategy, forming the periodic current waveform. This novel coating is expected to enhance the microhardness and wear performance within the grain size range of the inverse Hall–Petch (HP) relationship. The critical size of the HP relationship was estimated at 13 nm based on the relationship between different grain sizes and microhardness. Compared to the coating prepared by electrochemical deposition, the average grain sizes decrease from 8.4 ± 1.4 nm to 4.5 ± 1.6 nm. In addition, the microhardness was enhanced by approximately 28 %; the wear rate was decreased by approximately 58 %. The main mechanisms include abrasive, fatigue, and slight oxidation wear. This unique structure may enhance the resistance to grain boundaries mediated plastic deformation.
•The critical HP size of FeNi coating is approximately 13 nm.•Average grain size decreases from 8.4 ± 1.4 to 4.5 ± 1.6 nm.•The microhardness and the wear resistance are enhanced.•The wear mechanism includes abrasive, fatigue, and slight oxidation wear.•GBs mediation is the main plastic deformation mechanism.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
We recently demonstrated the chemical reprogramming of human somatic cells to pluripotent stem cells (hCiPSCs), which provides a robust approach for cell fate manipulation. However, the utility of ...this chemical approach is currently hampered by slow kinetics. Here, by screening for small molecule boosters and systematically optimizing the original condition, we have established a robust, chemically defined reprogramming protocol, which greatly shortens the induction time from ∼50 days to a minimum of 16 days and enables highly reproducible and efficient generation of hCiPSCs from all 17 tested donors. We found that this optimized protocol enabled a more direct reprogramming process by promoting cell proliferation and oxidative phosphorylation metabolic activities at the early stage. Our results highlight a distinct chemical reprogramming pathway that leads to a shortcut for the generation of human pluripotent stem cells, which represents a powerful strategy for human cell fate manipulation.
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•A robust three-stage chemically defined reprogramming protocol•Highly reproducible and efficient generation of hCiPS cells•Cells undergo a more direct and rapid molecular trajectory toward pluripotency•A unique metabolic reprogramming fuel cell proliferation and cell fate transition
Chemical reprogramming provides a robust approach for cell fate manipulation. Here, Deng and colleagues developed a highly reproducible and efficient chemical reprogramming method for the induction of human pluripotent stem cells and revealed increased cell proliferation and OXPHOS activity early in this reprogramming process.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Co content plays a crucial role in the magnetic and electric properties in Co doped ZnO (ZnO:Co) films. In this work, the method of RF source-assisted molecular-beam vapour deposition was used to ...prepare ZnO:Co films with various Co contents. The doped Co2+, the metal Co, and the oxygen vacancies (Vo) were found in the deposited films. The surface roughness and the crystalline size of the ZnO:Co films also increased by using bigger Co content. The prepared ZnO:Co films show n-type conductivity and room temperature ferromagnetism. By increasing the Co content, the content of the metal Co exceeded that of the doped Co2+ gradually, which led to the higher electric conductivity, carrier concentration, mobility, and saturation magnetization.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In order to extract useful information from X-ray fluorescence (XRF) spectra and establish a high-accuracy prediction model of soil heavy metal contents, a hybrid model combining a deep belief ...network (DBN) with a tree-based model was proposed. The DBN was first introduced into feature extraction of XRF spectral data, which can obtain deep layer features of spectra. Owing to the strong regression ability of the tree-based model, it can offset the deficiency of DBN in prediction ability so it was used for predicting heavy metal contents based on the extracted features. In order to further improve the performance of the model, the parameters of model can be optimized according to the prediction error, which was completed by sparrow search algorithm and the gird search. The hybrid model was applied to predict the contents of As and Pb based on spectral data of overlapping peaks. It can be obtained that R2 of As and Pb reached 0.9884 and 0.9358, the mean square error of As and Pb are as low as 0.0011 and 0.0058, which outperform other commonly used models. That proved the combination of DBN and tree-based model can obtain more accurate prediction results.
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NUK, OILJ, SAZU, UKNU, UL, UM, UPUK
The effects of rare earth elements (La, Gd) addition on the microstructure and the mechanical properties of as-extruded Mg-Al-Zn magnesium alloy under conditions of a medium temperature (230 °C) and ...a slow ram speed (0.1 mm/s) have been throughly investigated. The results show that the as-extruded bar presents smooth surface from the macroscopic view due to the fact that many non-basal dislocations and few pyramidal 〈c + a〉 dislocations could be activated to enhance the formability in the extrusion process. A bimodal grain structure composed of fine dynamic recrystallized (DRXed) grains with globular Mg17Al12 precipitates located at grain boundaries and non-recrystallized (non-DRXed) coarse grains with thin continuous precipitation laths inside is generated in the alloy. More dislocation pile-ups and subgrain boundaries are exhibited in the DRXed region which shows a typical texture of extruded alloys containing rare earth elements. The modified extruded alloy shows much higher strength than that of as-extruded AZ80 under either tension or compression condition owing to grain refinement strengthening, precipitation strengthening, solid-solution strengthening, dislocation strengthening and subgrain strengthening. The finer DRXed grain size and the fine precipitates in the modified extruded alloy bring about its lower yield anisotropy. In addition, large and fragile Al2Gd and Al8Mn4Gd phases mainly give rise to the decrease in ductility of the modified extruded alloy.
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•An as-extruded AZ80LG alloy presents excellent mechanical properties.•An improvement of formability in the extrusion process has been achieved.•Grain size and Mg17Al12 precipitates have been refined and modified.•More dislocation pile-ups and subgrain boundaries are exhibited in the alloy.•The tension-compression asymmetry of the alloy has been further weakened.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
To solve the problems of large taper and poor surface quality of micro-holes processed by laser direct machining (LDM), this study proposed a laser and backside electrolytic hybrid machining (LEM) ...method. This method can reduce the taper and remove slags, recast layer and micro-cracks, thus obtaining high-quality micro-holes. In this study, a picosecond pulsed laser was used to drill 304 stainless-steel sheets. The quality of micro-holes is compared between LDM and LEM before and after optimizing the processing parameters; and the effect of electrolytic voltage and power frequency on the quality was studied. The results show that LDM can reduce the defects by optimizing the processing technology. The roundness is drilled by optimized LDM increased by approximately 30.5%; and the taper is reduced by approximately 35.4%. In contrast, LEM can further improve the outlet roundness and reduce the taper, the oxygen content, and inner roughness based on LDM. The taper decreased by approximately 31.6%; the roundness of the hole outlet increased by approximately 14.8%; the oxygen content and roughness of hole wall decreased by approximately 60.1 and 65.4%, respectively. With the increase in electrolytic voltage, the quality of the inner wall becomes better, but the stray corrosion near inlet becomes worse. With the increase in the power supply pulse frequency, the edge and wall texture are more uniform and clearer, and the processing localization is enhanced.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Human pluripotent stem-cell-derived islets (hPSC-islets) are a promising cell resource for diabetes treatment
. However, this therapeutic strategy has not been systematically assessed in large animal ...models physiologically similar to humans, such as non-human primates
. In this study, we generated islets from human chemically induced pluripotent stem cells (hCiPSC-islets) and show that a one-dose intraportal infusion of hCiPSC-islets into diabetic non-human primates effectively restored endogenous insulin secretion and improved glycemic control. Fasting and average pre-prandial blood glucose levels significantly decreased in all recipients, accompanied by meal or glucose-responsive C-peptide release and overall increase in body weight. Notably, in the four long-term follow-up macaques, average hemoglobin A1c dropped by over 2% compared with peak values, whereas the average exogenous insulin requirement reduced by 49% 15 weeks after transplantation. Collectively, our findings show the feasibility of hPSC-islets for diabetic treatment in a preclinical context, marking a substantial step forward in clinical translation of hPSC-islets.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
