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Abstract Purpose Few studies have focused on the risk factors leading to postoperative blood transfusion after open reduction and internal fixation (ORIF) of proximal humeral fractures (PHFs) in the elderly. Therefore, we designed this study to explore potential risk factors of blood transfusion after ORIF for PHFs. We have also established a nomogram model to integrate and quantify our research results and give feedback. Methods In this study, we retrospectively analyzed the clinical data of elderly PHF patients undergoing ORIF from January 2020 to December 2021. We have established a multivariate regression model and nomograph. The prediction performance and consistency of the model were evaluated by the consistency coefficient and calibration curve, respectively. Results 162 patients met our inclusion criteria and were included in the final study. The following factors are related to the increased risk of transfusion after ORIF: time to surgery, fibrinogen levels, intraoperative blood loss, and surgical duration. Conclusions Our patient-specific transfusion risk calculator uses a robust multivariable model to predict transfusion risk.The resulting nomogram can be used as a screening tool to identify patients with high transfusion risk and provide necessary interventions for these patients (such as preoperative red blood cell mobilization, intraoperative autologous blood transfusion, etc.).

Learning experiences can affect students' interest in STEM (science, technology, engineering, and mathematics) careers. Applying the social cognitive career theory, this study tested and compared the effect size and effect mechanism of formal learning experiences (FLE) and informal learning experiences (ILE) on 1133 tenth-grade students' interest in STEM careers (ISC) through a paper questionnaire survey. The results of structural equation model analysis showed that: 1) The total effect of ILE on students' ISC is much greater than that of FLE; 2) ILE, STEM self-efficacy (SSE) and STEM careers perceptions (SCP) can directly affect students' ISC; FLE and ILE can also indirectly affect students' ISC through the mediating role of SSE and SCP. The analyses suggest that in order to improve students' ISC, STEM education (especially informal STEM education) should be strengthened, both formal and informal education should pay attention to the cultivation of students' SSE and SCP.

【Objective】 Bioavailable phosphorus and oxygen are key factors affecting root activity and crop yield. The objective of this paper is to elucidate how phosphorus fertilization and irrigation-water aeration combined to affect root physiological traits, zinc absorption and allocation in rice and grain yield at maturation stage. 【Method】 The experiment was conducted in pots using the variety of Liangyou 608 as the model plant. It consisted of two irrigation treatments: aerating irrigation (OI) and conventional irrigation (NI), and four phosphorus fertilizations: 0.00 (P1), 1.35(P2), 2.7 (P3), 4.05g /pot (P4). In each treatment, we measured root activity, root acid phosphatase activity at different growth stages, as well as zinc allocation and grain yield at maturation stage. 【Result】 ① Phosphorus fertilization reduced zinc content in the iron-manganese films by 33.38% to 60.41%, while oxygenating irrigation water increased the transfer coefficient of zinc from root to straw by 24.98% to 113.15%. Aeration and phosphorus fertilization combined to increase zinc content in straw, but reduce the transfer coefficient of zinc from straw to grains. ② The combination OI+P1 gave the highest grain yield, 1000-grain weight, effective panicle numbers and zinc distribution, which were 140.45 g/pot, 27.57 g, 29.00 per plant and 29.52%, respectively. ③ Phosphorus application increased root activity at tillering stage, reduced root acid phosphatase activity at filling stage, inhibited the absorption and accumulation of zinc in roots at maturation stage, promoted transfer of zinc from straw to grain, and increased grain yield and seed setting rate. Aeration and phosphorus fertilization reduced the activity of root acid phosphatase at tillering stage, increased the activity of root acid phosphatase at filling stage, and increased the zinc content in rice straw and grain, but reduced the number of effective panicles, seed setting rate and the transferability of zinc from straw to grain. 【Conclusion】 Phosphorus fertilization combined with irrigation-water aeration affects the formation of rice yield due to their influence on the physiological characteristics of the rice roots at tillering and filling stages, as well as zinc translocation to grains. Irrigation-water oxygenation promoted the absorption and distribution of zinc in rice straw.

Background: Females are underrepresented in Science, Technology, Engineering, and Mathematics (STEM) fields all over the world. To encourage more girls to choose STEM majors and careers, it is critical to increase their interest in STEM careers. Many studies have investigated the factors that influence females' entry into STEM fields, but few studies have explored the gender differences in the relationships between these factors. Therefore, based on the Social Cognitive Career Theory, this study explored the gender differences in the effects of environmental factors (school education, informal education, social support, and media) on high school students' interest in STEM careers through the mediating roles of STEM self-efficacy and STEM careers perceptions. Results: A questionnaire survey was conducted among 1240 high school students in Hunan Province, China, and the results of t-test, regression analysis, and structural equation model multi-group comparison showed that: Firstly, the scores of male students in all the dimensions except for STEM career perception were significantly higher than those of female students. Secondly, the environmental factor that had the greatest effect on male and female students' interest in STEM careers was different. Finally, there were gender differences in the mediating roles of STEM self-efficacy and STEM careers perceptions between environmental factors and interest in STEM careers. Conclusions: This study revealed the influence mechanisms and gender differences in male and female students' interest in STEM careers in the context of Chinese Confucian culture, and the conclusions are as follows: (1) Male students' interest in STEM careers was significantly higher than that of female students; (2) The environmental factors that had the greatest effect on male and female students' interest in STEM careers were social support and media, respectively; and (3) Environmental factors could affect male students' interest in STEM careers through the mediating roles of STEM self-efficacy and STEM career perception, while environmental factors could affect female students' interest in STEM careers through the mediating role of STEM self-efficacy. Finally, the mediating mechanisms of STEM self-efficacy and STEM career perception between environmental factors and interest in STEM careers, and the importance of STEM self-efficacy for female students were discussed.

Abstract Xrv proteins are a group of regulators in Xanthomonas spp., belonging to the histone-like nucleoid-structuring (H-NS) proteins of Gram-negative bacteria. The rice bacterial leaf streak pathogen Xanthomonas oryzae pv. oryzicola (Xoc) harbors three Xrv proteins, the XrvA, XrvB, and XrvC. Here, we report that in Xoc, the XrvB but not XrvA and XrvC is involved in negative regulation of the type III secretion system (T3SS) encoded by hrp genes. As with other Xanthomonas spp., the T3SS is an essential virulence determinant of Xoc and the expression of the hrp genes in Xoc is controlled by the HrpG/HrpX regulatory cascade. HrpG positively regulates the expression of HrpX, which in turn activates the transcription of the hrp genes. We provide evidences to demonstrate that the XrvB binds to the promoter region of hrpG and represses its transcription. Furthermore, we found that XrvB production was induced in the Xoc cells cultured in a nutrient-rich medium compared to a hrp-inducing minimal medium. We also found that in Xoc, the hrpG expression level is inversely correlated with the content of XrvB, and XrvB occupancy at hrpG promoter region is positively correlated with XrvB levels. Our data suggest that XrvB is a determinative factor controlling the expression levels of HrpG. In addition, mutation analysis revealed that the Xoc XrvB also plays positive roles in regulating bacterial growth, cell motility, and stress tolerance. Our findings provide important insights into the molecular mechanism of T3SS expression regulation in Xoc.

In the iron and steel industry, evaluating the energy utilization efficiency (EUE) and determining the optimal energy matching mode play an important role in addressing increasing energy depletion and environmental problems. Electric Arc Furnace (EAF) steelmaking is a typical short crude steel production route, which is characterized by an energy-intensive fast smelting rhythm and diversified raw charge structure. In this paper, the energy model of the EAF steelmaking process is established to conduct an energy analysis and EUE evaluation. An association rule mining (ARM) strategy for guiding the EAF production process based on data cleaning, feature selection, and an association rule (AR) algorithm was proposed, and the effectiveness of this strategy was verified. The unsupervised algorithm Auto-Encoder (AE) was adopted to detect and eliminate abnormal data, complete data cleaning, and ensure data quality and accuracy. The AE model performs best when the number of nodes in the hidden layer is 18. The feature selection determines 10 factors such as the hot metal (HM) ratio and HM temperature as important data features to simplify the model structure. According to different ratios and temperatures of the HM, combined with k-means clustering and an AR algorithm, the optimal operation process for the EUE in the EAF steelmaking under different smelting modes is proposed. The results indicated that under the conditions of a low HM ratio and low HM temperature, the EUE is best when the power consumption in the second stage ranges between 4853 kWh and 7520 kWh, the oxygen consumption in the second stage ranges between 1816 m3 and 1961 m3, and the natural gas consumption ranges between 156 m3 and 196 m3. Conversely, under the conditions of a high HM ratio and high HM temperature, the EUE tends to decrease, and the EUE is best when the furnace wall oxygen consumption ranges between 4732 m3 and 5670 m3, and the oxygen consumption in the second stage ranges between 1561 m3 and 1871 m3. By comparison, under different smelting modes, the smelting scheme obtained by the ARM has an obvious effect on the improvement of the EUE. With a high EUE, the improvement of the A2B1 smelting mode is the most obvious, from 24.7% to 53%. This study is expected to provide technical ideas for energy conservation and emission reduction in the EAF steelmaking process in the future.

Through optimizing and improving the guide system and atomizer, the spherical TiAl alloy powders with low oxygen content and high fine powder yield were prepared by water-cooled copper crucible vacuum induction melting gas atomizing technology, using the TiAl alloy blocks as the raw materials. In the results, the graphite guide base with good thermal conductivity and the BN ceramic guide core with erosion resistance can not only ensure the heating of guide pipe, but also effectively prevent the erosion of molten metal. The spiral nozzle atomizer moves the atomization point downward, and the position of reflux area is far away from the outlet of guide pipe, which solves the problem of liquid column backflow. The spiral distribution tube can effectively restrain the atomized gas, reduce the kinetic energy loss, and significantly improve the yield of fine powders by more than 20%. The fluidity of the spherical TiAl alloy powders prepared in the experiment is 27.7 [s·(50 g)‒1], the sphericity is more than 90%, and the oxygen incremental is small, which are suitable for the 3D printing and injection molding.

The spherical Ti‒1Al‒8V‒5Fe alloy (Ti185) powders used for the additive manufacturing were prepared by plasma rotating electrode atomization (PREP), using the high temperature forged Ti185 rods with the diameter of 100 mm as the electrode bar, using the Ti185 alloy ingots without “βspots” prepared by vacuum consumable arc melting as the raw materials. The properties of the Ti185 powders were characterized by vibration sieving, scanning electron microscope (SEM), and X-ray diffraction (XRD). In the results, the particle size distribution of the Ti185 powders is wide, mainly in the range of 44~150 μm. The powder yield with the particle size less than 44 μm is 11.6%. The oxygen content of the powders (mass fraction) is less than 0.14%. The powder fluidity with the particle size less than 150 μm is 24.79 [s∙(50 g)‒1], the bulk density is 2.79g∙cm‒3, and the tap density is 2.99 g∙cm‒3. The Ti185 powders are composed of β phase due to the rapidly cooling during the PREP process. The powders exhibit the high sphericity without the satellite powders. The powders with the particle size larger than 124 μm show the cellular dendrite structure with the small amount of rough and uneven micro pores on the surface of powders. The internal organization of the powders shows the characteristics of multi-point nucleation with the cellular structure and coarse grains after the rapid solidification. With the decrease of particle size and the increase of cooling rate, the cellular dendrite structure on the surface of powders decreases gradually, showing the smooth surface for the powder particle size less than 44 μm. Meanwhile the internal organization of the powders shows a radial growth trend and significant refinement.

This review summarizes the mechanism of fatigue and the research achievements of active components in anti-fatigue such as polysaccharides and peptides from marine organisms in recent years. Finally, discussed the shortcomings and future direction of development of marine bioactive substances.