The Y-shaped 2219 Al-Cu alloy transition ring is a critical load-bearing component in launch vehicle propellant tanks. Traditional manufacturing methods, which involve machining rectangular rings into Y-shaped ones, suffer from low material utilization and disruption of metal flow lines. This study proposes a novel mold-constrained mandrel expansion process, integrating constrained forming with warm deformation, to precisely form Y-shaped Al-Cu alloy rings with fine microstructure and excellent mechanical properties. In this process, a constrained circular mold and mandrel are used to form a cavity, allowing the billet to flow into the cavity and take shape with high precision. Forming at warm temperature enhances the stored energy and promotes recrystallization, resulting in an equiaxed fine-grain structure. A constitutive recrystallization model for 2219 Al-Cu alloy under warm deformation was developed, and the grain refinement parameter range was determined. Finite element simulations using Deform-3D were employed to optimize the forming process, yielding an optimal billet shape and processing parameters to ensure uniform and sufficient deformation, as well as full cavity filling. Using this optimized process, Y-shaped Al-Cu alloy rings were successfully produced with complete cross-sectional filling, low anisotropy, and excellent mechanical properties. Material utilization was doubled, the average grain size ranged from 81 mu m to 134 mu m, and the three-directional ultimate tensile strength was 465-480 MPa with an elongation of 10-14 %, all of which exceed the required mechanical property standards.
Excessive consumption of fluoride can cause skeletal fluorosis. Mitophagy has been identified as a novel target for bone disorders. Meanwhile, calcium supplementation has shown great potential for mitigating fluoriderelated bone damage. Hence, this study aimed to elucidate the association between mitophagy and skeletal fluorosis and the precise mechanisms through which calcium alleviates these injuries. A 100 mg/L sodium fluoride (NaF) exposure model in Parkin knockout (Parkin-/-) mice and a 100 mg/L NaF exposure mouse model with 1% calcium carbonate (CaCO3) intervention were established in the current study. Fluoride exposure caused the impairment of mitochondria and activation of PTEN-induced putative kinase1 (PINK1)/E3 ubiquitin ligase Park2 (Parkin)-mediated mitophagy and mitochondrial apoptosis in the bones, which were restored after blocking Parkin. Additionally, the intervention model showed fluoride-exposed mice exhibited abnormal bone trabecula and mechanical properties. Still, these bone injuries could be effectively attenuated by adding 1% calcium to their diet, which reversed fluoride-activated mitophagy and apoptosis. To summarize, fluoride can activate bone mitophagy through the PINK1/Parkin pathway and mitochondrial apoptosis. Parkin-/- and 1% calcium provide protection against fluoride-induced bone damage. Notably, this study provides theoretical bases for the prevention and therapy of animal and human health and safety caused by environmental fluoride contamination.
In order to study the influence of the gas flow channel structure on the output performance of the flowing-gas diode pumped alkali vapor laser(FDPAL),we established the FDPAL theoretical model based on the gas heat transfer,fluid mechanics,and laser dynamics process in FDPAL using side pumping Rb va-por FDPAL(Rb-FDPAL)as the simulation object.The impacts of the gas flow direction,the cross-sectional area and the shape of the runner on the Rb-FDPAL's output performance were analyzed.The results show that with the horizontal flow method and by increasing the cross-sectional area of the flow channel and set-ting a masonry structure as the connection between the gas flow channel and the steam pool,we effectively suppress the vortex in the vapor,increase the gas flow rate,and decrease the thermal effect of the steam pool.Rb-FDPAL's laser output power and slope efficiency are higher,and the simulation results are consistent with the experiment.
Background:The presence of meconium is associated with gestational age, and the incidence of meconium aspiration syndrome (MAS) increases with gestational age. Our study compared the differences in the clinical characteristics of patients with MAS at different gestational ages and discussed the risk factors for neurological injury and death from MAS.Methods:A total of 294 neonates diagnosed with MAS between 2013 and 2021 were included. Patients were divided into preterm, early-term, full-term, and late-term groups according to gestational age. We compared the patients' basic demographic, treatment, complications, and clinical outcomes in the different groups. We also analyzed the risk factors of neurological injury and death in patients with MAS.Results:The mean age at admission (0.55 ± 0.9 h) was lower and the proportion of cesarean deliveries (90.00%, 27/30) was higher in the preterm group than in the other three groups. There was no statistically significant difference among the four groups regarding 1- and 5-min Apgar scores and the need for delivery room resuscitation. In terms of complications, early-term infants had the highest incidence of neurological injury (52.9%, 27/51), and late-term infants had the highest incidence of pneumothorax (37.8%, 17/45). The overall mortality rate of children with MAS was 7.80% (23/294), and the difference in mortality rates among the four groups was not significant. Low 1-min Apgar score and gestational age, metabolic acidosis, and respiratory failure were independent risk factors for neurological injury; metabolic acidosis, respiratory failure, and sepsis were independent risk factors for death in neonates with MAS.Conclusion:The clinical characteristics of MAS neonates of different gestational age are different mainly in complications. Early-term infants are more likely to complicate with neurological injury, and late-term infants are more likely to complicate with pneumothorax. Low 1-min Apgar score and gestational age, metabolic acidosis, and respiratory failure were established as risk factors for neurological injury; metabolic acidosis, respiratory failure, and sepsis were independent risk factors for death in neonates with MAS.
SUD2, a unique protein domain closely related to the pathogenesis of SARS-CoV-2, has been reported to bind with the G-quadruplex (G4), a special noncanonical DNA structure endowed with important functions in regulating gene expression. However, the interacting partner of SUD2, among other SARS-CoV-2 Nsps, and the resulting functional consequences remain unknown.
The microstructural evolution and corrosion behaviour of railroad flash-butt-welded U71Mn joints and the effect of heat treatment were investigated via scanning electron microscopy and electrochemical measurements. The joint structures were found to mainly comprise pearlite and a few ferrites. The grains became finer and more homogeneous after heat treatment. Additionally, there was a decrease in the corrosion current density (1.71 × 10−5 A cm−2) and increases in the absolute corrosion potential (0.86 mV) and corrosion resistance (1088.83 Ω−1cm2). This was primarily attributed to the fewer Cl− ions at the homogeneous grain boundaries and fewer oxidation reactions on the joints after heat treatment. The findings of this study explain corrosion failure and will guide the development of corrosion-resistant joints for improved railroad quality.
With the improvement of consumers' requirements for pork quality, the method of crossbreeding with excellent local pig breeds to improve meat quality is popular. Saba pig has high reproduction rate, good meat quality and high utilization rate of roughage, but its excellent characteristics have not been fully developed and utilized. To promote the development and utilization of Saba pigs and production of high-quality pork, the meat quality traits and glycolysis potential of Duroc × (Landrace × Yorkshire) (DLY), Berkshire × (Duroc × Saba) (BDS), and Duroc × (Berkshire × Saba) (DBS) three-way crossbred pigs were compared. The results showed that DLY had the highest live weight, carcass weight, lean meat percentage, drip loss, glycolysis potential, muscle diameter, and relative mRNA expression levels of type IIb muscle fibers as well as the lowest ultimate pH (p < 0.05). The lightness value of DBS was the highest (p < 0.05). Among the three crossbred pigs, myristic, arachidic, palmitoleic, and eicosenoic acids were the highest in BDS. These results indicated that the carcass traits of local crossbred pigs were worse than those of DLY pigs, but meat quality was markedly higher, with BDS showing the best meat quality.
Sexual maturation provides economically important traits in poultry production. Research on the initiation mechanism of sexual maturity is of great significance for breeding high-yield laying hens. However, the underlying mechanisms are not fully clear. Here, one hundred and fifty Chahua No. 2 laying hens (the CH2 group, which has precocious puberty) and one hundred and fifty Wu Liang Shan black-bone laying hens (the WLS group, a late-maturing chicken breed) with similar weights and ages were randomly selected. ELISA was used to determine the secretion levels of luteinizing hormone (LH), estradiol (E2), and progesterone (P4) in 150-day-old serum and small yellow follicle (SYF) tissues. A histology examination, immunohistochemistry, and quantitative real-time PCR (qPCR) were used to explore the molecular mechanism of how some genes related to oxidative stress affect sexual maturation. The results showed that the secretion levels of LH, E2, and P4 in the CH2 group serum and SYF were higher than those in the WLS group. The results of the real-time PCR of all genes showed that the expression levels of cytochrome P450 family 11 subfamily A member 1, steroidogenic acute regulatory protein, follicle-stimulating hormone receptor, and cytochrome P450 family 19 subfamily A member 1 in the CH2 group were significantly higher than those in the WLS groups (p < 0.001). Untargeted metabolomics combined with multivariate statistical analysis was used to identify biomarkers of SYF tissues in the CH2 and WLS groups. A trajectory analysis of the principal component analysis (PCA) results showed that the samples within the group were clustered and that the samples were dispersed between the CH2 and the WLS groups, indicating that the results of the measured data were reliable and could be used for further research. Further analysis showed that a total of 319 metabolites in small yellow follicles of the CH2 and WLS groups were identified, among which 54 downregulated differential metabolites were identified. These 54 metabolites were found as potential CH2 biomarkers compared with WLS at 150 days, and the different expressions of L-arginine, L-prolinamide, (R)-4-hydroxymandelate, glutathione, and homovanillic acid were more significant. Twenty metabolic pathways were found when significantly differential metabolites were queried in the KEGG database. According to the impact values of the metabolic pathways, eighteen differential metabolites belonged to the mTOR signaling pathway, glutathione metabolism, ABC transporters, the cell ferroptosis pathway, and D-arginine and D-ornithine metabolism. Interestingly, we identified that the cell ferroptosis pathway played an important role in chicken follicle selection for the first time. The histology and immunohistochemistry of SYF showed that the number of granulosa cells increased in the CH2 groups and the expression levels of glutathione peroxidase 4, tumor protein p53, ribosomal protein S6 kinase, and sterol regulatory element binding protein 1 in the granulosa cell layer were upregulated in the CH2 group at the time of sexual maturation. Furthermore, we also speculated that the antioxidant system may play an indispensable role in regulating sexual maturity in chickens. Overall, our findings suggest differentially expressed metabolites and metabolic pathways between CH2 and WLS chickens, providing new insights into the initiation mechanism of sexual maturation.
This paper proposes a novel density-based real-time segmentation algorithm, to extract ground point cloud in real time from point cloud data collected by roadside LiDAR. The algorithm solves the problems such as the large amount of original point cloud data collected by LiDAR, which leads to heavy computational burden in ground point search. First, point cloud data is filtered by straight-through filtering method and rasterized to improve the real-time performance of the algorithm. Then, the density of the point cloud in horizontal plane is calculated, and the threshold of the density is selected to extract the low-density regional point cloud according to the density statistical histogram and 95% loci. Finally, the low-density regional point cloud is used as the initial ground seeds for iterative optimization of ground parameters, and the ground point cloud is extracted by the fitted ground model to realize road point cloud extraction. The experimental results on 1055 frames of continuous data collected on real scenes show that the average time consumption of the proposed method is 0.11 s, and the average segmentation precision is 92.48%. This shows that the density-based road segmentation algorithm can reduce the time of point cloud traversal in the process of ground parameter fitting and improve the real-time performance of the algorithm while maintaining the accuracy of ground extraction.
To improve the friction and wear properties of a plasma-sprayed Ni/WC coating on a #45 steel substrate and explore the influence of spindle speed on the friction and wear properties of the coating in the process of hightemperature assisted ultrasonic rolling (HT/USR), The HT/USR processing of the Ni/WC coating was conducted under various spindle speeds (173, 248, and 360 r/min). The results showed that the pores and cracks in the Ni/ WC coating after HT/USR treatment were reduced, giving the coating a compact structure. The surface performance of the coating was the best when the spindle speed was 173 r/min. Compared with the untreated sample, the surface roughness of the coating treated by HT/USR-173 r/min was reduced by 49 %, and the surface hardness was increased by 38.4 %. The residual tensile stress was transformed from tensile stress to compressive stress, reaching 404.2 MPa. The wear mechanism of the coating after HT/USR treatment changed from abrasive and fatigue wear to abrasive and oxidation wear. The friction coefficient and wear amount decreased with decreasing spindle speed. The average friction coefficient and wear amount of the coating with a spindle speed of 173 r/min were the lowest, 0.03094 and 5.4 mg, respectively, which are 69.23 % and 64.23 % lower than those of the untreated sample. Therefore, HT/USR effectively improved the surface properties of the plasma-sprayed Ni/WC coatings, as well as their friction and wear properties.
Crop domestication for increasing growth rates and yields appears to have altered the features of adaxial and abaxial stomata, but its effect on leaf water use efficiency (WUE) have not been experimentally verified. In this study, we characterized stomatal anatomy and carbon isotope discrimination (δ13C) in 32 wild and 36 domesticated genotypes of cotton grown under agricultural field conditions. The results showed that domesticated genotypes possessed lower WUE, as indicated by low or more negative δ13C compared with wild genotypes. Higher theoretical maximum stomatal conductance (gsmax) after domestication was accounted for by more stomata rather than significantly enlarged stomata. Specifically, abaxial stomatal density was higher whilst there was no change in the adaxial density. The size of both adaxial and abaxial stomata was greater due to larger guard cells but without there being any increase in pore size. However, there was a negative relationship between δ13C and stomatal size across wild and domesticated genotypes, especially on the abaxial leaf surface, because bigger stomata resulted in a lower maximum stomatal response rate to fluctuating canopy light, resulting in increased water loss. Overall, our results indicate that cotton domestication has resulted in substantial variation in stomatal anatomy, and that WUE and drought tolerance can potentially be improved in future breeding by decreasing the size of abaxial stomata to produce a faster stomatal response and hence a reduction in unnecessary water loss.
Acute-on-chronic liver failure (ACLF) is a common clinical emergency and critical illness with rapid progression and poor prognosis. This study aims to establish a more efficient system for the prognostic assessment of hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF), which will provide a guiding scheme for subsequent treatment and improve the survival rate of patients. Data on 623 patients with HBV-ACLF were recorded. Univariate and multivariate analyses were performed to determine the discriminative abilities of the novel prognostic assessment model in predicting 90-day mortality. The area under the receiver operating characteristic curve was used to evaluate the accuracy of the models. Patients were divided into high- and low-scoring groups based on the best critical values, and survival rates were analyzed using Kaplan-Meier survival analysis and compared by applying log-rank tests. The area under the curve of the new scoring system established using the results of the first reexamination, the results of the first examination, the mean daily change in these results (MDCR) and the results of other first examinations were 0.911 (95% confidence interval [CI]: 0.889, 0.933), 0.893 (95% CI: 0.868, 0.917), and 0.895 (95% CI: 0.871, 0.919), respectively. The final prognostic scoring system established using the results of the first reexamination was chosen as a novel prognostic assessment model, and patients with lower scores (first reexamination results [FRER] score ≤ 3.65) had longer survival times (P < .001). The prognostic scoring system established using the FRER combined with other examination results can better assess the prognosis of HBV-ACLF at 90 days.
Cermet coatings are post-treated by a new surface microcrystallization technology, namely high-temperature-assisted ultrasonic deep rolling (HT + UDR). The process parameters of ultrasonic deep rolling significantly affect the microstructure and tribological properties of the Ni-WC coatings. In this paper, the samples were treated with different preloading depths (0.20 mm, 0.25 mm, and 0.30 mm), and the microstructure and properties of the coatings were characterized by SEM, EDS, X-ray stress analysis, and micro-Vickers hardness testing. An MMW-1A-type friction and wear tester was used for the dry friction and wear test at room temperature, respectively. Compared with the untreated sample, plastic rheology occurred on the surface of the coatings after HT + UDR, showing a phenomenon of “cutting peaks and filling valleys”. In the treated coatings, visible cracks were eliminated, and the inside of the coating was denser. The surface hard phase was increased as a “skeleton” and embedded with the soft phase, which played a role in strong and tough bonding. After HT + UDR + 0.25 mm treatment, the surface roughness increased by 68%, the microhardness of the surface layer reached a maximum of 726.3 HV0.1, and the residual tensile stress changed from 165.5 MPa to −337.9 MPa, which inhibited the germination and propagation of cracks. HT + UDR improved the wear resistance of the coating in many aspects. The coating after the 0.25 mm preloading depth treatment possessed the smallest friction coefficient and the lowest wear amount, which is 0.04 and 4.5 mg, respectively. The wear form was abrasive wear, and the comprehensive tribological performance is the best.
The hormone receptor (HR) status and human epidermal growth hormone receptor 2 (HER2) status of patients with breast cancer may change following neoadjuvant chemotherapy (NAC). We retrospectively analyzed the clinical data of 294 patients with stage II/III breast cancer to evaluate the clinical significance and prognostic value of receptor transformation after NAC in breast cancer patients. Pathological complete response after NAC was achieved in 10.7% of patients. HR, estrogen receptor (ER), progesterone receptor (PR), HER2, and Ki-67 conversion rates were 9.2%, 6.5%, 13.0%, 4.4%, and 33.7%, respectively. Patients with stable HR ( P = 0.01) and HER2 ( P = 0.048) expression had more favorable overall survival (OS). Low or reduced Ki-67 expression was associated with better disease-free survival (DFS) ( P < 0.001) and OS ( P < 0.01). Multivariate analysis showed that the number of lymph nodes after NAC, HR conversion, and radiotherapy were independent prognostic factors for overall survival. HR conversion implied a higher risk of death [hazard ratio, 2.56 (95% confidence interval: 1.19–5.51); P = 0.016]. Patients with HR conversion after NAC who received endocrine therapy had better DFS ( P = 0.674) and OS ( P = 0.363) than those who did not receive endocrine therapy, even if the HR changed from positive to negative. In conclusion, pathological testing should be performed before and after NAC, and even patients with HR conversion after NAC might benefit from endocrine therapy.
Biochar, as a soil amendment for synergizing the reduction of pollution and carbon emissions, shows great potential and future prospects in controlling antibiotic contamination. In order to research the effects of biochar on antibiotic behaviors in soil systematically, a Meta-analysis was conducted based on 20 studies published from 2011 to 2021. The results showed that the adsorption and degradation of antibiotics in the soil were significantly affected by the application rate and property of biochar. A 2% biochar application dose seemed to be the highest effect size (ES) of 0.19 on adsorption, while there was a significant effect (ES=0.23) on the degradation when the application rate was 5%. The specific surface area, polarity, stability, and aromaticity of biochar could increase the partition coefficient significantly, and the ES was 0.11, 0.13, 0.09, and 0.18, respectively, whereas the effects of antibiotic transport on the dose and property of biochar were insignificant. Biochar also indirectly controlled antibiotic behavior by altering the soil environment. However, the response of the coupling mechanism in antibiotic behaviors on biochar application into soil is still unclear. Moreover, the long-term and negative effects of biochar application in the field are still lacking basic data.
Excess fluoride (F) exposure can cause oxidative stress in the kidney. As an antioxidant, selenium (Se) can potentially protect the kidney from F-induced injury in rats. Hence, the histopathological, renal biochemical, oxidative stress, and apoptotic-related indices upon exposure to 100 mg/L sodium fluoride (NaF) and various doses of sodium selenite (Na2SeO3; 0.5, 1, and 2 mg/L) were assessed. Our results demonstrated that F-mediated renal structural damage and apoptosis elevated the content of serum creatinine (SCr), inhibited the activity of catalase (CAT) in serum, and increased the production of reactive oxygen species (ROS) in kidney and malondialdehyde (MDA) in serum. Interestingly, 1 mg/L dietary supplementation of Se tangibly mitigated these injuries. Furthermore, F could also change the gene and protein expression of the nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and NAD(P)H quinone oxidoreductase1 (NQO1). Concomitantly, the different concentrations of Se notably alleviated their expression. Taken together, 1-2 mg/L Se ameliorated Finduced renal injury through oxidative stress and apoptosis-related routes. The recorded ameliorative effects might be related to the activation of the Nrf2/HO-1/NQO1 signaling pathway.
This paper proposes an adaptive frequency estimator based on the observable canonical form. The signal model is first constructed in the form of the state space representation and transformed into the observable canonical form. The state observer of the signal model is then designed based on the observable canonical form. In addition, the structure of the observer is analyzed in detail with respect to the number of the frequency components. The design of the frequency-related parameters in the observer is also given in a theorem, based on which the adaptive frequency estimator is proposed with three main parts including an adaptive observer, an auxiliary filter and a frequency estimator. The proposed adaptive frequency estimator is finally validated on the simulated voltage signals with different harmonics for power quality monitoring.