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In this work, the influence of Si concentration on the microstructure and growth of plasma electrolytic oxidation (PEO) coatings on two types of Al–Si–Mg aluminum alloys were investigated. we utilized a multiscale correlative methodology to analyze the microstructure and micro-defect characteristics of the PEO coatings formed on A357 and 6082 aluminum alloys. The results demonstrate that both coatings exhibit a porous structure and are primarily composed of alumina and amorphous phases. Notably, the PEO coating formed on A357 alloy exhibits lower thickness, higher porosity, and more non-uniform barrier layer compared to that on 6082 alloy due to a higher concentration of Si in the substrate. Advanced X-ray computed tomography effectively characterizes micro-defects with different morphologies within the two coatings. Through microstructural observation and micro-defect characterization, we elucidate the influence of Si on the coating growth. [ABSTRACT FROM AUTHOR]

• Anodic oxidation coating's cracking causes a severe substrate stress concentration. • Sealing weakens anodic oxidation coating's cracking resistance during fatigue tests. • Prior shot peening enhances the fatigue property of anodic oxidation coated specimen. In this study, the effects of sealing and prior shot peening treatments on the fatigue behavior of the sulphuric acid anodic oxidation coated 6082-T6 aluminium alloy were investigated. Experimental results indicate that the preferential fracture of anodic oxidation coatings due to its higher brittleness and lower fracture toughness as well as the stress concentration of near-interface substrate caused by the interface cyclic dislocation accumulation could cause the fatigue failure of anodic oxidation coated specimens. Consequently, the fatigue property of anodic oxidation coated specimens notably decreases compared to as-machined specimens, with a decrease of 26.7 % in the fatigue limit corresponding to 2 × 107 fatigue cycles. Additionally, the sealing treatment introduces numerous cracks that penetrate the coating entirely, diminishing the coating's resistance to cracking under fatigue loading; this alteration changes the fatigue failure mechanism of anodic oxidation coated specimens, ultimately resulting in a decrease of 15.5 % in the fatigue limit of anodic oxidation coated specimens. Despite exacerbating the surface integrity and increasing the surface roughness of anodic oxidation coated specimens, the prior shot peening treatment increases the fatigue limit of anodic oxidation coated specimens by 82.8 % since the affecting layer beneath the interface plays a crucial role in inhibiting the further propagation of coating cracks into the substrate as well as the crack propagation in the substrate beneath the interface. [ABSTRACT FROM AUTHOR]

• The UPM and PI iterative methods can accurately reconstruct the residual stress field induced by rolling processing. • The extended finite element method and the weight function method are applied to solve the stress intensity factor. • The necessity of deep rolling treatment for axles is verified. • The influence of interference and initial crack position on the remaining life of axle is explored. • The damage tolerance analysis of the axle was carried out. Deep rolling surface strengthening is an effective way to introduce compressive residual stress (CRS) along the railway axle, which can improve the fatigue resistance of the material. The CRS field was rebuilt adopting the proportional-integral (PI) iteration method and the unit pressure method (UPM) to study the fatigue cracking behavior of deep-rolled EA4T railway axles. The remaining life prediction model and the stress intensity factor (SIF) solution method were then validated using simulations and testing with small-sized specimens. The remaining life of the EA4T railway axle was then calculated by applying a realistic vertical load spectrum. The results showed that CRS prevented crack propagation, enhanced the critical propagation size of railway axle cracks, and prolonged the remaining life of the axle. Additionally, the remaining life of the axle may not support the following maintenance period if a crack with an extendable size emerges at the unloading groove of the railway axle. This work provides a theoretical basis for the optimization of the non-destructive testing (NDT) interval of deep-rolled EA4T railway axles. [ABSTRACT FROM AUTHOR]

• Prior shot peening improves the CF limit of AO coated aluminum alloy by 50 %. • AO specimens exhibit different CF failure modes under low and high applied stress. • Substrate residual stress and microstructure affect the CF crack propagating path. • Substrate residual stress relaxes in distinct mode under low and high applied stress. Plain (anodic oxidation) and composite (prior shot peening + anodic oxidation) coatings were prepared to investigate their effects on the corrosion-fatigue (CF) property of 6082-T6 aluminium alloy in a 3.5 wt% NaCl aqueous solution. The results indicate that plain coated specimens exhibited similar CF properties to as-machined specimens at low applied stresses. However, under high applied stresses, the plain coating led to a preferential fracture and was unable to effectively prevent corrosion medium. Hence, the CF property of plain coated specimens was found to be inferior to as-machined specimens at high applied stresses. The synergetic effect of substrate residual stress and microstructure beneath the coating-substrate interface reduced the crack propagating rate in the initial stage by deflecting the crack at the grain boundary. Therefore, the CF property of composite coated specimens improved as a whole when compared with as-machined and plain coated specimens. Besides, under low applied stresses, the near-interface substrate residual stress of composite coated specimens occurred the relaxation due to the substrate crack propagation, while under high applied stresses, this was due to the synergetic effect of materials' local cyclic yield and plastic flow, as well as the substrate crack propagation. [ABSTRACT FROM AUTHOR]

Survivin is a promising marker for the diagnosis of bladder cancer. The accuracy and clinical value of urinary survivin mRNA expression were compared with urine cytology, which is the standard diagnostic method for bladder cancer. Scientific databases, including PubMed, Web of Science, Cochrane Library and China National Knowledge Infrastructure, were searched in order to find studies that examined urinary survivin mRNA expression and urine cytology in the diagnosis of bladder cancer. Quality assessment was performed using the Quality Assessment of Diagnostic Accuracy Studies 2 tool in Revman 5.3 and data analysis was conducted using Stata/MP. The I2 statistic was used to evaluate heterogeneity and Deeks' funnel plot was generated to assess the possibility of publication bias. A total of 15 studies that evaluated a total of 1,624 patients were included in the present meta-analysis. The pooled sensitivity and specificity values for the detection of urinary survivin mRNA expression in the diagnosis of bladder cancer were 0.86 [95% confidence interval (CI), 0.81–0.90] and 0.95 (95% CI, 0.93–0.96), respectively. Regarding urine cytology, the pooled sensitivity and specificity values were 0.42 (95% CI, 0.36–0.48) and 1.00 (95% CI, 0.98–1.00), respectively. Furthermore, the differences in pooled sensitivity were statistically significant in the diagnosis of grade 1 and 2 bladder tumors. Summary receiver operating characteristic curve values for urinary survivin mRNA expression and urine cytology were 0.95 (95% CI, 0.93–0.97) and 0.86 (95% CI, 0.83–0.89), respectively. Urinary survivin mRNA expression was also more accurate compared with other diagnostic indicators, including positive likelihood ratios, negative likelihood ratios, diagnostic odds ratios and Youden's index. Compared with traditional urine cytology, urinary survivin mRNA detection using reverse transcription-PCR was identified to be more effective in the diagnosis of early bladder cancer. [ABSTRACT FROM AUTHOR]

An alloyed ferritic-pearlitic steel is studied after micro-shot peening with balls from a high-speed steel. The morphology and the roughness of the surface of the specimens are determined. Specimens with smooth and notched surfaces are subjected to multi-cycle fatigue tests. The fatigue resistance of the specimens with a smooth surface and with a notched surface increases by 22 and 27%, respectively, after the shot-peening. Observation of crack growth in specimens with small holes shows that micro-shot peening hinders crack propagation. [ABSTRACT FROM AUTHOR]

Abstract In this study, the precipitate strengthened Cu-Ni-Si alloy was micro-shot peened by ceramic balls with a diameter of 40 μm. The fatigue tests using the peened specimens were conducted in air and in salt atmosphere respectively. The results show that a fine and hardening layer is formed on the surface of peened specimen and the compressive residual stress is introduced. There is no fatigue limit for specimens in both test conditions. The S-N curve of specimens in salt atmosphere shows a continuous decrease with the increasing number of loading cycles, while that in air shows a step-wise shape. Compared with the un-peened specimens, the fatigue strengths of specimens at 107 cycles are increased by 47% and 67% in air and in salt atmosphere respectively. The peened specimens in air condition failed from subsurface zone in high cycle fatigue region, while all the other specimens failed from surface. The micro-shot peening can improve the surface property and delay the crack initiation and propagation, so as to enhance the fatigue strength greatly. Highlights • The fatigue failure changes from surface to subsurface by micro-shot peening. • Micro-shot peening can delay both the crack initiation and early propagation. • The micro-shot peening can further improve the fatigue strength in salt atmosphere. [ABSTRACT FROM AUTHOR]

Abstract Tb3+-doped CaAl LDH with fluorescent property has been prepared in ethanol/water media. After it is exposed to 0.01, 0.05, 0.10, and 0.25 mol L−1 cytosine solution, respectively, the amount of the cytosine present in the Tb3+-doped CaAl-LDH/Cyt-n composites is separately about 0.01, 0.01, 0.03, and 0.05 mol per 1 mol Tb3+-doped CaAl-LDH by compositional analysis. XRD patterns reveal some reflections attributed to cytosine in some composites. IR spectra show that bands attributed to cytosine appear in some composites. Fluorescent spectra suggest that the intensity of the emission due to 5D 4 —7F 5 transition of Tb3+ gradually increases with increasing amount of the cytosine present in the Tb3+-doped CaAl-LDH. The mechanism of fluorescence enhancement based on the intermolecular energy transfer from cytosine to Tb (III) has been proposed and discussed. Graphical abstract The effect of cytosine on the fluorescence of Tb3+-doped CaAl LDH has been studied. The emission attributed to 5D 4 →7F 5 transition of Tb3+ doped in CaAl-LDH gradually became stronger with increasing amount of cytosine incorporated in the Tb3+-doped CaAl-LDH. Meanwhile, the lifetime of the emission ascribed to 5D 4 →7F 5 transition of Tb3+ gradually decreases with the increase in the amount of cytosine present in the Tb3+-doped CaAl-LDH. The mechanism of fluorescence enhancement based on the intermolecular energy transfer from cytosine to Tb3+ in the Tb3+-doped CaAl-LDH/Cyt. composites has been proposed. fx1 [ABSTRACT FROM AUTHOR]

The effect of shear-affected zone (SAZ), with a stress-concentration source induced by the punching process, on tensile properties was investigated. Tests using honed specimens (which have the same shapes and stress-concentration without any SAZ) and smooth specimens were conducted to compare the effect with that of the punched specimens. Dual-phase steel, which has a high work-hardening ability and low yield strength, and precipitation-hardened steel, which has a low work-hardening ability and high yield strength, were used in the tests. Materials with two tensile strength grades were prepared from both types of steel. Only the precipitation-hardened steel with higher strength grade punched specimen showed a brittle fracture with extremely short fracture-elongation, whereas the other specimens showed a ductile fracture. The fracture surface analysis revealed that cracks initiated in the maximum shear stress plane of the SAZ under tensile loading at first. We call the crack “shear crack.” The steel which showed brittle fracture used in this study easily exhibited plastic-strain localization compared with the other steels. If the shear crack is sharp, then the transition from ductile to brittle failure tends to occur. Furthermore, the strength characteristics of the punched specimen depend on the crack length dependency of the strength resistance and the failure phenomenon of the original material. [ABSTRACT FROM AUTHOR]

• The surface properties of EA4T axle steel treated by ultrasonic surface rolling process (USRP) are investigated. • Effect of USRP on the electrochemical corrosion resistance and corrosion fatigue performance is elucidated. • Residual stress relaxation mechanism of USRP-treated EA4T axle steel in air and corrosion is revealed. • Influence of residual stress relaxation on the corrosion fatigue resistance is clarified. The fatigue properties and residual stress relaxation behavior of EA4T axle steel treated by ultrasonic surface rolling process (USRP) are investigated in air and corrosive environments. The result reveals that the surface roughness (Ra) is decreased from 1.42 to 0.17 μm after the USRP. A surface layer with ultrafine grains, work hardening, and compressive residual stress (CRS) is achieved by the USRP. Compared with the as-machined specimens, the USRP specimens exhibit slightly lower electrochemical corrosion resistance but superior fatigue performance in air and corrosive environments. The dislocation density is significantly decreased in the corrosive environment during fatigue loads, accompanied by a rapid relaxation of surface CRS. The influence of USRP on the corrosion fatigue performance is elucidated. The residual stress relaxation mechanism and its influence on fatigue resistance are also analyzed. [ABSTRACT FROM AUTHOR]

This work reports micro-defects and growth mechanism of the plasma electrolytic oxidation (PEO) coating formed on the surface of 6082-T6 aluminum alloy. Scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray computed tomography techniques were used to characterize the morphology, phase, microstructure, and porosity of the PEO coating, respectively. The results confirmed a porous outer layer and a dense inner layer in the coating. The PEO coating was composed of γ- and α-Al 2 O 3 phases, and amorphous phases. A layer with only amorphous structures was found near the coating/substrate (C/S) interface, which could be ascribed to the high concentration of P element in the electrolyte. Micro-defects with different sizes and shapes inside the coating were successfully characterized by the high-resolution X-ray computed tomography technique, and the volume reconstruction result revealed a porosity fraction of 5.43% for the coating. A growth model was complemented to explain the growth mechanism and interconnected micro-defects of the PEO coating. • Micro-defects in the plasma electrolytic oxidation (PEO) coating formed on 6082-T6 alloy were firstly characterized by high-resolution X-ray computed tomography technique. • Formation of the amorphous structure at the coating/substrate (C/S) interface was highly dependent on P element in the electrolyte. • Growth mechanism of the coating was clarified based on the microstructural observation and micro-defect characterization. [ABSTRACT FROM AUTHOR]

Low, medium and high-intensity (0.19, 0.26 and 0.34 mmA) shot peening treatments and 0.34 mmA high-intensity shot peening combined with slight and severe polishing treatments were used as the pre-treatments to improve the fatigue property of micro-arc oxidation (MAO) coated 6082-T6 aluminum alloy, respectively. In consideration of the significance of substrate residual stress beneath the coating-substrate interface on MAO coated specimens' fatigue property, the substrate residual stress of various coated specimens was analyzed by the X-ray's powerful penetrability. Results indicate that the substrate residual stress state of MAO coated specimens is changed from tensile (+93 MPa) to compressive (−65 to −93 MPa) by the above pre-treatments, which is beneficial for inhibiting the crack initiation at the substrate or resisting the crack's further propagation from the coating into the substrate. Whereas, similar to the compressive residual stress induced by shot peening, the compressive substrate residual stress for prior shot peening + MAO composite coated specimens will also relax during the fatigue tests. In addition, the gradient compressive residual stress beneath the interface induced by prior shot peening reduce the crack propagating rate, thus improving the fatigue property of coated specimens; after the 0.26 mmA shot peening pre-treatment, the fatigue strength at 2 × 107 cycles of MAO coated specimens increases by 59.1 %. Finally, the effects of surface and interface roughness, substrate residual stress and in-depth compressive residual stress on the fatigue life of MAO coated specimens are further discussed. • Pre-treatments improve MAO coated Al alloys' fatigue life by 2.41 to 4.35 times. • Grain refinement of substrate increases MAO coatings' pore size and thickness. • Compressive substrate residual stress inhibits crack propagation beneath interface. • Compressive substrate residual stress relaxes by 8 % to 41 % at 104 fatigue cycles. [ABSTRACT FROM AUTHOR]

• CSP and MSP are used to improve the fatigue property of bare and MAO coated Al. • CSP and MSP introduce a grain-refined and CRS affected layer on surface. • CSP and MSP is more appropriate for MAO coated and bare Al, respectively. • Crack initiation stage dominates the fatigue property of bare Al. • Crack propagation stage dominates the fatigue property of MAO coated Al. Conventional shot peening (CSP) and micro-shot peening (MSP) are used to enhance the fatigue property of bare and micro-arc oxidation (MAO) coated 6082-T6 aluminum. The difference in the anti-fatigue strengthening mechanism of CSP and MSP on bare and MAO coated 6082-T6 aluminum alloy is revealed. Results show that MSP provides a more significant improvement in fatigue properties of bare specimens than CSP since the intensely inhibiting effect on crack initiation. Nevertheless, MAO coating impairs the surface integrity of MSP specimens, thus reducing the crack initiating life. In comparison, the effect of deeper affected layer induced by CSP on the improvement of crack propagating life is mostly retained after the MAO process. Hence, for the MAO coated specimen, the CSP prior-treatment is more effective in improving its fatigue property. [ABSTRACT FROM AUTHOR]

• Fatigue life prediction method of 25CrMo4 steel is investigated using fracture mechanics and machine learning methods. • Residual stress relaxation process is incorporated into fatigue crack growth in combination with NASGRO equation and equivalent initial flaw size (EIFS) methodology. • Different machine learning methods areemployed to investigate theireffectiveness in fatigue life prediction. In this work, fracture mechanics and machine learning methods are separately employed to predict the high cycle fatigue (HCF) life of micro-shot peened 25CrMo4 alloy steel containing artificial notches. The influences of notch size, stress level, and surface condition on fatigue life are incorporated into the prediction model. The results shows that the fatigue life of shot-peened specimens is enhanced by the compressive residual stress (CRS) compared with that of the un-peened specimens. The prediction result using fracture mechanics method is within the error band of ±2, while that using machine learning method almost lies in the error band of ±1.5. The stress level and notch size are the most critical factors affecting the HCF fatigue life. The applicability and limitation of the two methods are finally discussed. [ABSTRACT FROM AUTHOR]

Carburized and quenched specimens of 17CrNiMo6 gear steel were given two different shot peening treatments. Post-treatment Vickers hardness, residual stress, roughness and topography were determined. Traditional shot peening can increase surface hardness, residual stress and roughness. By contrast, micro-shot peening can decrease of surface roughness and increase both the surface hardness and residual stress even more. Scuffing tests were carried out using a ring-in-V-notch test configuration. It was found that shot peening can improve the scuffing resistance properties of gear steel, and that a combination of traditional shot peening and micro-shot peening can improve the scuffing resistance of carburized and quenched gear steel to the largest degree. The hardness and residual compress stress, roughness and topography produced during shot peening have an effect on the scuffing resistance of the carburized and quenched gear steel. [ABSTRACT FROM AUTHOR]

A field experiment was performed to study the effects of waterlogging on the leaf mesophyll cell ultrastructure, chlorophyll content, gas exchange parameters, chlorophyll fluorescence, and malondialdehyde (MDA) content of summer maize (Zea mays L.) hybrids Denghai605 (DH605) and Zhengdan958 (ZD958). The waterlogging treatments were implemented for different durations (3 and 6 days) at the third leaf stage (V3), the sixth leaf stage (V6), and the 10th day after the tasseling stage (10VT). Leaf area index (LAI), chlorophyll content, photosynthetic rate (Pn), and actual photochemical efficiency (ΦPSII) were reduced after waterlogging, indicating that waterlogging significantly decreased photosynthetic capacity. The chloroplast shapes changed from long and oval to elliptical or circular after waterlogging. In addition, the internal structures of chloroplasts were degenerated after waterlogging. After waterlogging for 6 d at V3, the number of grana and grana lamellae of the third expanded leaf in DH605 were decreased by 26.83% and 55.95%, respectively, compared to the control (CK). Those in ZD958 were reduced by 30.08% and 31.94%, respectively. Waterlogging increased MDA content in both hybrids, suggesting an impact of waterlogging on membrane integrity and thus membrane deterioration. Waterlogging also damaged the biological membrane structure and mitochondria. Our results indicated that the physiological reactions to waterlogging were closely related to lower LAI, chlorophyll content, and Pn and to the destruction of chloroplast ultrastructure. These negative effects resulted in the decrease of grain yield in response to waterlogging. Summer maize was the most susceptible to damage when waterlogging occurred at V3, followed by V6 and 10VT, with damage increasing in the wake of waterlogging duration increasing. [ABSTRACT FROM AUTHOR]

The effects of micro-shot peening (MSP) and artificial surface defects were investigated in relation to the defect tolerance of Al-Si-0.6Mg alloy in the framework of fracture mechanics. The results indicated that coral-shaped casting defects inside the alloy could be effectively quantified using the X-ray synchrotron radiation technique. An affected layer with a surface roughness (Ra) of 1.25 and residual stress of − 125 MPa was introduced on the MSP specimen compared to the un-peened (UP) specimen. The fatigue strengths of the UP and MSP specimens containing the artificial defects decreased as the defect size increased under rotating bending fatigue tests, except in the case of defects with the equivalent size of 395 and 490 µm, respectively. MSP could shift the crack initiation site toward the subsurface, while all the cracks of the specimens with the artificial defects originated from the surface and maintained an aspect ratio of 0.66 during the crack growth process. The relationship between the defect sizes and the fatigue strengths could be reasonably assessed by the modified Kitagawa-Takahashi (K-T) diagrams. The critical defect size of the MSP specimens was increased from 450 to 542 µm compared with that of the UP specimens, owing to the beneficial effect of the compressive residual stress. The defect tolerance of the Al-Si-0.6Mg alloy was improved by the MSP process. • Effects of micro-shot peening (MSP) on the fatigue properties of Al-Si-0.6Mg alloy are explored. • Casting defect inside the alloy was identified using synchrotron radiation X-ray computed microtomography (SR-μCT) technique. • The influence of MSP on the fatigue tolerance was characterized by Kitagawa-Takahashi (K-T) diagrams. • The critical defect size harmless to fatigue strength was evaluated using fracture mechanics. [ABSTRACT FROM AUTHOR]

• Effects of the corrosive environment on the fatigue strength of EA4T axle steel are explored. • The evolution of corrosion process during fatigue loading is fully investigated. • Crack aspect ratio in the corrosive environment is obtained by using synchrotron radiation X-ray computed microtomography (SR-μCT). • Fatigue life prediction model is developed based on the pit growth, short crack growth, and long crack growth stages. High-speed railway axle is the critical safety component of modern ground vehicles, which experiences extremely complex environments. In this paper, the effect of corrosion on the fatigue behavior of EA4T axle steel was investigated in an artificial rainwater environment. Combining scanning electron microscopy (SEM) and synchrotron radiation X-ray micro computed microtomography (SR-μCT) with theoretical analysis, damage measurement enabled a full evolution characterization of the corrosion process for exploring the corrosion mechanism and its influence on the fatigue life. It is found that the corrosive environment significantly reduced fatigue strength and facilitated multiple crack initiation, while showed relatively little effect on the long fatigue crack growth. The fitness of the 3-P Weibull distribution was slightly higher than that of the Gumbel distribution in terms of crack population. The life prediction model incorporating the pit growth, short crack, and long crack stages showed a good agreement within the 95% and 5% probabilistic S-N curve. [ABSTRACT FROM AUTHOR]

• The extended finite element method is used in the fracture mechanics simulation of EA4T axle steel specimen and full-scale axle. • Numerical model is built considering residual stress and wheelset press-fitting. • The effectiveness of the extended finite element method (XFEM) was verified by comparing the simulation and experimental results. • The measured load spectrum was applied, and the NASGRO equation was used to calculate the residual life of the axle. High-speed railway axles may be damaged during service or maintenance. Therefore, to ensure axle service safety, the residual life of damaged axles is necessary for an accurate assessment. In this study, a small-sized specimen was analyzed and the effectiveness of the extended finite element method (XFEM) was verified by comparing the simulation and test results. Subsequently, the residual life of the EA4T axle with an initial crack was evaluated using the XFEM, which is based on fracture mechanics, and the actual axle service load spectrum. The results show that the critical failure sizes for the residual life of the power axle and non-power axle were 7 and 4 mm, respectively, for a crack located in the middle of the axle body; in contrast, for a crack located in the arc transition of the wheel seat, the critical failure dimensions were 9 and 5 mm, respectively. Based on the NASGRO equation and considering the damage tolerance safety factor, the residual lives of the power axle for the two crack locations were estimated to be 1.3953 × 106 and 9.636 × 105 km, respectively, while those of the non-power axle were 2.095 × 106 and 1.2583 × 106 km, respectively. The results of this study can provide a reference for the axle non-destructive testing (NDT) period. [ABSTRACT FROM AUTHOR]

In this study, the very high cycle fatigue tests were conducted on a kind of high-strength austempered ductile iron (ADI) at 90 Hz and 20 kHz. The S – N curves decrease continuously and there is no fatigue limit in the very high cycle fatigue regime. The fatigue strength of the different frequencies essentially corresponds with each other and the specimens show similar fracture behaviors. Meanwhile, on the fracture surfaces of some specimens, the ‘granular-bright-facet’ (GBF) area is observed. The threshold stress intensity factor for internal crack growth is obtained and the fatigue limit is evaluated based on the defect size. [ABSTRACT FROM AUTHOR]

In this paper, The combination of back-propagation neural network (BPNN) and genetic algorithm (GA) is used to optimize the current collection quality of the pantograph-catenary system. The contact force standard deviation (CFSD) between pantograph and catenary is utilized as the optimization index. The optimization works in this paper are as follows. 1. The equivalent mass, stiffness, and damping of the pantograph. 2. The distance between each dropper and the positioning point. 3. The length of each dropper. 4. The tension of contact wire, messenger wire, and stitch wire. Firstly, a pantograph-catenary coupling simulation model verified by EN 50318: 2018 and the line experiment result is established in this paper. Then, the pantograph-catenary coupling simulations are conducted according to the experiments designed by center composite design (CCD). The BPNN models accurately reflecting the relationship between the optimized input parameters and the output CFSD are established. Subsequently, the minimum CFSD of the BPNN model and the corresponding optimal parameter combinations are searched through GA. Finally, an evaluation method based on the BPNN weight matrix and the Garson equation is used to quantify the relative importance of the input optimized parameters of the established BPNN. [ABSTRACT FROM AUTHOR]

Abstract: Austempered ductile irons (ADIs) with three strength grades were produced successfully by different two-stage heat treatments. The microstructure and mechanical properties of ADIs such as tensile strength, yield strength, elongation and impact toughness were studied. The results show that the strengths of the three grades ADIs well satisfy the requirement of ASTM standard 897M-06 grade 900/650/09, grade 1050/750/07 and grade 1200/850/04. Meanwhile, the ductile and impact toughness of the ADIs are larger than those required by the ASTM standard. The microstructure has obvious influence on mechanical properties and fracture behavior. With the decrease of austempering temperature, yield strength and tensile strength of the ADIs increase, while both the impact energy and elongation of them decrease. [Copyright &y& Elsevier]

Abstract: In the present investigation, 35CrMo alloy steel was gas oxynitrocarburized at 550°С, 570°С and 610°С for 2h by applying a low-temperature gas multi-elements penetrating system. Microstructure, surface composition, case depth, microhardness, wear and corrosion resistance were analyzed. The compound layer consisting of γ′-Fe4N and ε-Fe3N and oxide layer of Fe3O4 and Fe2O3 were formed on the ground reference surface after treated. Compared with the conventional gas nitrocarburizing, a larger effective case depth was obtained successfully in a short time after treatment. The microhardness and the properties of wear and corrosion resistance were improved obviously and the properties of samples treated at 570°C are optimum when compared with the samples treated at 550°С and 610°С for the same duration. [Copyright &y& Elsevier]

Abstract: Stem cells play an essential role in cellular specialization and pattern formation during embryogenesis and in tissue regeneration in adults. This is mainly due to a stem cell''s ability to replenish itself (self-renewal) and, at the same time, produce differentiated progeny. Realization of these special stem cell features has changed the prospective of the field. However, regulation of stem cell self-renewal and maintenance of its potentiality require a complicated regulatory network of both extracellular cues and intrinsic programs. Understanding how signaling regulates stem cell behavior will shed light on the molecular mechanisms underlying stem cell self-renewal. In this review, we focus on comparing the progress of recent research regarding the roles of the BMP signaling pathway in different stem cell systems, including embryonic stem cells, germline stem cells, hematopoietic stem cells, and intestinal stem cells. We hope this comparison, together with a brief look at other signaling pathways, will bring a more balanced view of BMP signaling in regulation of stem cell properties, and further point to a general principle that self-renewal of stem cells may require a combination of maintenance of proliferation potential, inhibition of apoptosis, and blocking of differentiation. [Copyright &y& Elsevier]

In humans, mutations in BMPR1A, SMAD4 and PTEN are responsible for juvenile polyposis syndrome, juvenile intestinal polyposis and Cowden disease, respectively. The development of polyposis is a common feature of these diseases, suggesting that there is an association between BMP and PTEN pathways. The mechanistic link between BMP and PTEN pathways and the related etiology of juvenile polyposis is unresolved. Here we show that conditional inactivation of Bmpr1a in mice disturbs homeostasis of intestinal epithelial regeneration with an expansion of the stem and progenitor cell populations, eventually leading to intestinal polyposis resembling human juvenile polyposis syndrome. We show that BMP signaling suppresses Wnt signaling to ensure a balanced control of stem cell self-renewal. Mechanistically, PTEN, through phosphatidylinosital-3 kinase-Akt, mediates the convergence of the BMP and Wnt pathways on control ofß-catenin. Thus, BMP signaling may control the duplication of intestinal stem cells, thereby preventing crypt fission and the subsequent increase in crypt number. [ABSTRACT FROM AUTHOR]

Objective To investigate the serum levels of liver function - related proteins (Cholinesterase, ChE; album, Alb, prealbumin, PA; transferrin, TRF; ferritin, FRT; C - reactive protein, CRP; and ceruloplasmin, CER) and assess their clinical diagnostic significance for chronic hepatitis B virus (HBV) carriers. Methods The study selected 86 HBV carriers who were diagnosed in the Affiliated Yong - Chuan Hospital of Chongqing Medical University from January 2012 to July 2014 (the observation group). Additionally, 102 healthy individuals who underwent physical examination in the hospital were selected (the control group). Biochemical indices including serum ChE, Alb, PA, FRT, TRF, CRP, and CER levels were measured in both groups. Liver biopsy was performed in part of the observation group. Group comparison of continuous data was performed using the independent - samplest test. Results Serum CER levels in the observation and control groups were (0.20 ± 0.04) g/L vs (0.29 ± 0.06) g/L, showing a statistically significant difference (t = 2.03, P = 0.03). No significant differences occurred in the rest of biochemical indices between groups (P > 0.05 for all). Serum CER levels were significantly decreased in patients with higher severity of liver inflammation and fibrosis [(0.23 ± 0.01) g/L vs (0.18 ± 0.02) g/L, t = -2.6, P = 0.01; (0. 22 ± 0.02) g/L vs (0.17 ± 0.04) g/L, t = -3.2, P = 0.004]. Conclusion The change in serum CERlevel can reflect the severity of liver inflammation and fibrosis in the early stage. Thus, serum CER level may become an important index for early diagnosis and treatment of HBV carriers. [ABSTRACT FROM AUTHOR]

In recent years, the frequency and intensity of exposure to heat stress have increased gradually, seriously hampering the production of maize. This paper presents a study designed to analyze how the development, physiology and dispersal of pollen from the heat‐resistant maize variety Zhengdan958 and the heat‐sensitive maize variety Xianyu335 are affected by exposure to heat stress during the tasselling stage. Our results showed That exposure to heat stress significantly increased the antioxidant enzyme activity in pollen. Upon visual inspection of the pollen, we found that the lower water content had given rise to wrinkles in the pollen surface, sunken germination pores, and morphological deformations. In addition, the anther dehiscence process was hindered, resulting in a reduced amount of pollen being dispersed. We also found elevated levels of abscisic acid (ABA), jasmonic acid (JA) and its derivatives, indole acetic acid (IAA) and gibberellin‐3 (GA3) in heat‐pollens, as well as elevated ratios of IAA to ABA and ABA to GA3. Ultimately impaired pollen fertility. Summarizing, our experiment revealed that reduced pollen quantity and quality are significant contributors to fertility losses in summer maize exposed to heat stress at anthesis, and we hope that our analysis of the physiological mechanisms involved can contribute to the development of crop management measures aimed at countering the increasingly detrimental effects of heat stress on the production of summer maize. [ABSTRACT FROM AUTHOR]

The greenhouse effect caused by global warming was becoming more and more obvious, resulting in increased frequency of high temperature and high humidity, which significantly affected maize productivity. However, it was poorly understood how the interactions of high temperature and high humidity affected leaf senescence, photosynthetic performance and yield of summer maize. Three stress treatments including (a) high temperature stress (T), (b) waterlogging stress (W) and (c) complex stress (T‐W) were set at the third leaf stage (V3), the sixth leaf stage (V6) and the tasselling stage (VT) in 2019–2020 to explore the influence mechanism of complex stress. Each stress treatment period lasted 6 days. Non‐stressed plants served as control. Yield, antioxidant enzyme activity, photosynthetic characteristics, and dry matter accumulation were determined. Our study found that the activity of antioxidant enzymes was significantly decreased, while malonyldialdehyde (MDA) accumulation was increased under each stress treatment. As a result, the photosynthetic characteristics were impaired, manifested in a significant decrease in net photosynthetic rate (Pn), enzyme activities of phosphoenolpyruvate carboxylase (PEPCase) and ribulose diphosphate carboxylase (RUBPCase). The decrease in photosynthetic intensity affected by each stress treatment led to a significant decrease in total dry matter accumulation and grain yield. The most significant effects of waterlogging and combined stresses on yield occurred at the V3 stage, followed by the V6 and VT stages. However, the most significant effects of high temperature occurred at the VT stage, followed by the V6 and V3 stages. Moreover, the compound stress exacerbated damage to leaf senescence and photosynthetic properties of summer maize compared to the single stress of high temperature or waterlogging. [ABSTRACT FROM AUTHOR]

• A new type of CFRP Bars reinforced Coral Concrete was developed; • Test was performed, the mechanical property of this type of structure was studied; • Crack development process for this type of new structure is discovered. • A new formula to predict the crack width of this new type structure is developed. In order to study the crack development of CFRP reinforced coral concrete under different bending conditions, experimental study investigation of crack width of steel and CFRP reinforced coral concrete beams were performed. A comparative study of cracking rate, maximum crack height and crack patterns in CFRP bars reinforced coral concrete beams at different stages is made with ordinary steel reinforced coral concrete beams. The results show that under similar reinforcement ratio, the crack width and crack spacing of CFRP reinforced coral concrete beams are larger than that of steel reinforced concrete beams, increasing the reinforcement ratio of test beams can effectively reduce the crack width. The current deign formula from existing design codes overestimates the value of the relative bond characteristic coefficient (v i) and the strain inhomogeneity coefficient (ψ). Therefore, in this paper, the formula for maximum crack width of CFRP bars reinforced beams is developed based on the experimental data, the relative bond characteristic coefficient, the strain inhomogeneity coefficient of the longitudinal reinforcement, the ratio of the maximum crack width to the average crack width (τ s) are included in the formula. The formula is validated with test results, the calculated value agrees well with the experimental results. Therefore, can be used for the future design. [ABSTRACT FROM AUTHOR]

In this study, a comparative study of carbon fiber reinforced polymer (CFRP) bar and steel–carbon fiber composite bar (SCFCB) reinforced coral concrete beams was made through a series of experimental tests and theoretical analyses. The flexural capacity, crack development and failure modes of CFRP and SCFCB-reinforced coral concrete were investigated in detail. They were also compared to ordinary steel-reinforced coral concrete beams. The results show that under the same conditions of reinforcement ratios, the SCFCB-reinforced beams exhibit better performance than CFRP-reinforced beams, and stiffness is slightly lower than that of steel-reinforced beams. Under the same load conditions, the crack width of SCFCB beams was between that of steel-reinforced beams and CFRP bar-reinforced beams. Before the steel core yields, the crack growth rate of SCFCB beam is similar to the steel-reinforced beams. SCFCB has a higher strength utilization rate—about 70–85% of its ultimate strength. Current design guidance was also examined based on the test results. It was found that the existing design specifications for FRP-reinforced normal concrete is not suitable for SCFCB-reinforced coral concrete structures. [ABSTRACT FROM AUTHOR]

In this study, the effects of micro-shot peening and artificial defect on the fatigue properties of EA4T railway axle steel were evaluated. Un-peened (UP) and micro-shot peened (MSP) EA4T axle steel specimens were drilled to introduce artificial defects on the surface. Then the fatigue tests were conducted on a rotary bending fatigue machine (R = −1). The test results showed that the fatigue limit of the UP specimens was improved by 25% after MSP; when the equivalent defect sizes were less than 60 and 70 μm respectively, they had no negative effect on the fatigue strength of the UP and MSP drilled specimens, otherwise the fatigue strength of both specimens decreased with the increase of the defect size. The fracture surfaces were analyzed by scanning electron microscopy (SEM) observations, which indicated that crack initiation sites for the as-prepared UP and MSP specimens were on the surface, while for the drilled specimens, they were on the vicinity of hole defects. The effect of artificial defect size on the fatigue strength of the UP and MSP specimens and the critical defect size were analyzed with fracture mechanics approach, the results of which showed that the relationship between defect size and fatigue strength of the UP and MSP specimens can be well evaluated by the modified Haddad model, and the critical defect size of the UP specimens was 65 μm while that of the MSP specimens was increased to 76 μm due to the introduction of compressive residual stress. [ABSTRACT FROM AUTHOR]

In this study, EA4T axle steel specimens were subjected to three shot peening treatments: conventional shot peening (CSP), micro-shot peening (MSP) and their combination, i.e. dual shot peening (DSP). The residual stress, surface roughness, morphology, microhardness, were used to characterize the affected surface layer. The results indicated that MSP achieved maximum surface compressive residual stress (SCRS), minimum surface roughness, high surface microhardness. Moreover, compared to CSP, DSP improved the SCRS and microhardness while reducing surface roughness. However, scanning electron microscopy (SEM) observations indicated the presence of intensive defects of the DSP-treated specimens, which hindered the fatigue strength of the specimens. Fatigue tests were conducted to evaluate the effect of different treatments on fatigue life, the median S - N curve demonstrated that the fatigue limit at 107 cycles was improved by 24, 32, and 27% for the CSP, MSP, and DSP specimens, respectively. Furthermore, SEM observation was conducted to analyze the fracture mechanisms, the results indicated that the failure of all specimens originated at the surface and the fracture mechanisms were not changed by the shot peening treatments. The SCRS during the cyclic loading have also been analyzed. Moreover, the factors influencing fatigue limit improvement were discussed. [ABSTRACT FROM AUTHOR]

• Cause and consequence analysis for industrial hot work is conducted. • The ABT model and PN are integrated to analyze hot work accident evolution. • An improved regional center method is developed to obtain crisp evaluation value. • Data fitting is performed for probability calculation. Hot work poses great hazards to industrial operation site. Although regulatory and guidance exist, accidents caused by hot work continue to occur. Risk assessment has proved to be an effective method for risk control. However, current studies paid less attention to the evolution process of industrial hot work accidents and the quantitative risk assessment seems to be insufficient. In this context, we aimed to perform comprehensive risk evolution analysis and quantitative risk assessment of hot work using adaptive bow tie (ABT) and Petri nets (PNs). The ABT model is improved to analyze deep causes, consequences, and their relationships. PNs are employed to conduct quantitative risk assessment. To address uncertainties, the triangular membership function and improved regional center method are proposed to calculate the confidences of all places and transitions in the PNs. The probabilities are finally obtained by data fitting method. The study found that the most likely consequence of hot work accident is near miss. The results also indicate that hot work accident prevention measures should emphasize on the isolation of workplace, combustible gases test, removal of combustible substances, job organization, and job training. Besides, emergency devices maintenance and emergency drilling are critical to prevent accidents from expanding. [Display omitted] [ABSTRACT FROM AUTHOR]

It's well known that the development and distribution of roots could be regulated to obtain deep soil resource and enhance the grain yield by increasing the depth of fertilization, but little is known about whether increasing P fertilization depth can optimize the root distribution to delay leaf senescence, enhance photosynthetic performance and root-shoot coordination or not. We conducted a field experiment that tested the following four placement depths of P fertilization: 5 cm (P 5), 10 cm (P 10), 15 cm (P 15), and 20 cm (P 20). The experiment was designed to explore the regulatory effects of the P fertilization depth on the root growth and distribution, the photosynthetic performance, the root-shoot coordination, the yield formation, the N and P fertilizer utilization of maize plants. We found that deep P placement did indeed alter the root parameters. In the 20–60 cm soil layer, both the root dry weight and length of P 15 treatment were on average 23.2% higher than those of P 5 treatment. The specific root length and specific root surface area of P 15 treatment were 4.5% and 5.6% higher than those of P 5 treatment. In addition, the P 15 treatment achieved a significantly improved photosynthetic performance over the P 5 treatment: The leaf area index at the R6 stage was 10.2% higher, the leaf senescence index from the R2 to the R6 stages was 31.4% lower, the photosynthetic rate at the R3 stage was 25.9% higher. The P placement depth also optimized the root-shoot coordination: The ratios of root weight to shoot weight, root surface area to leaf area, and root length to leaf area of P 15 treatment were 6.7%, 13.8%, and 12.7% higher than those of P 5 treatment, respectively. Finally, the root P and N uptake efficiency, the photosynthetic P-use efficiency, and the physiological P-use efficiency of P 15 treatment were all significantly higher than those of P 5 treatments. And together these responses had the effect of increasing the mature biomass by 12.5%, and the grain yield by 22.0%. In conclusion, increasing the P fertilization placement depth to 15 cm regulates the growth and development of the root system, which in turn improves the capability of plant to uptake and utilize N and P in the soil, delays the onset of leaf senescence, enhances its photosynthetic performance and biomass accumulation rate, and thus ultimately increases the yield. [Display omitted] • Deep P fertilization optimizes root growth, and root-shoot coordination. • Deep P fertilization delays leaf senescence and improves photosynthetic performance. • Optimized root-shoot coordination improves the grain yield and nutrient use efficiency. [ABSTRACT FROM AUTHOR]

6‐Benzyladenine (6‐BA, a synthetic cytokinin) could improve the ability to resist adversity. However, very little attention has been given to its role in alleviating waterlogging damages on grain growth. A field experiment was performed to investigate effects of exogenous 6‐BA after waterlogging for 6 days at the third leaf stage (V3‐WL + 6‐BA) or the sixth leaf stage (V6‐WL + 6‐BA) on grain filling, and endogenous hormone of summer maize hybrids DengHai605 (DH605) and ZhengDan958 (ZD958), which were planted popularly in China. Exogenous 6‐BA alleviated waterlogging damages on grain filling by improving grain weight and volume, which was beneficial to yield increase. Grain yield of DH605 under V3‐WL + 6‐BA and V6‐WL + 6‐BA increased by 16% and 12%, respectively, compared with that of V3‐WL (waterlogging at the third leaf stage) and V6‐WL (waterlogging at the sixth leaf stage), while the corresponding values for ZD958 increased by 20% and 15%, respectively. Moreover, exogenous 6‐BA alleviated waterlogging damages on grain endogenous hormone content by increasing levels of endogenous indole‐3‐acetic acid, zeatin riboside, and gibberellic acid, and decreasing level of abscisic acid in grain of waterlogged summer maize during grain‐filling periods. Clearly, exogenous 6‐BA improved grain‐filling characteristics, and endogenous hormone, resulting in a significant yield increase of waterlogged summer maize. [ABSTRACT FROM AUTHOR]

Global climate changes have led to frequent and recurrent heat stress, which has seriously affected the world maize production. The experiment presented in this paper was carried out during the maize‐growing season in 2021 and 2022 at the Huang–Huai–Hai Region Maize Science and Technology Innovation Center (36°09′N, 117°09′E) in Tai'an, Shandong province, China. The test site is located in the semi‐humid warm temperate continental monsoon climate zone, soil is brown loam. We selected different heat‐sensitive maize varieties: heat‐tolerant variety Zhengdan 958 (ZD958) and heat‐sensitive variety Xianyu335 (XY335) to study the stress effects of high temperature on the development of tassel in the key stage of its differentiation (the 12‐leaf stage, V12). We found that exposure to heat stress during the V12 stage significantly reduced the tassel size and the anther dehiscence area, making it difficult to disperse pollen, thus effectively reducing pollen production. In addition, heat stress had significant negative effects on pollen development, resulting in deformed pollen and lower pollen viability and germination rate. Our results also showed that heat stress significantly increased the activities of key reactive oxygen species‐scavenging enzymes including superoxide dismutase, peroxidase and catalase, and that the malondialdehyde and H2O2 content in tassels exposed to heat stress were significantly higher than those control group, where it should be noted that for the XY335, these effects were more pronounced than for the ZD958. The endogenous hormone content of tassels exhibited a variety of responses. After heat stress, the zeatin and salicylic acid content in tassels of both maize varieties were significantly lower than those in the respective control groups, while the abscisic acid and gibberellin acid content were significantly higher. With respect to the jasmonic acid and 3‐indoleacetic acid content, the two maize varieties exhibited opposite responses: in tassels from ZD958 plants subjected to heat stress were higher than those in the respective control group, while in tassels from XY335 plants, they were lower. The observed changes in protective enzyme activities and endogenous hormone contents induced by heat stress significantly affected the development of maize tassels and significantly reduced the amount, activity and germination rate of pollen. [ABSTRACT FROM AUTHOR]

Background: Acute lung injury is characterized by overwhelmingly elevated PAI-1 in both lung edema fluid and the circulating system. The role of increased PAI-1, encoded by Serpine1 gene, in the regeneration of injured lung epithelium has not been understood completely. This study aimed to investigate the role of Serpine1 in the regulation of alveolar type 2 epithelial cell (AT2) fate in a humanized mouse line carrying diseased mutants (Serpine1Tg). Methods: Wild-type (wt) and Serpine1Tg AT2 cells were either cultured as monolayers or 3D alveolospheres. Colony-forming assay and total surface area of organoids were analyzed. AT1 and AT2 cells in organoids were counted by immunohistochemistry and fluorescence-activated cell sorting (FACS). To test the potential effects of elevated PAI-1 on the permeability in the epithelial monolayers, we digitized the biophysical properties of polarized AT2 monolayers grown at the air–liquid interface. Results: A significant reduction in total AT2 cells harvested in Serpine1Tg mice was observed compared with wt controls. AT2 cells harvested from Serpine1Tg mice reduced significantly over the wt controls. Spheroids formed by Serpine1Tg AT2 cells were lesser than wt control. Similarly, the corresponding surface area, a readout of re-alveolarization of injured epithelium, was markedly reduced in Serpine1Tg organoids. FACS analysis revealed a significant suppression in the number of AT2 cells, in particular, the CD44+ subpopulation, in Serpine1Tg organoids. A lesser ratio of AT1:AT2 cells in Serpine1Tg organoids was observed compared with wt cultures. There was a significant increase in transepithelial resistance but not amiloride inhibition. Conclusions: Our study suggests elevated PAI-1 in injured lungs downregulates alveolar epithelial regeneration by reducing the AT2 self-renewal, particularly in the CD44+ cells. [ABSTRACT FROM AUTHOR]

Highlights • Effect of a shear-affected-zone (SAZ) on fatigue limit was investigated. • Tests on specimens with and without SAZ were conducted. • Propagation resistance of the fatigue crack has been lost by the punching process. • Fatigue crack growth mode had a possibility of transition from Mode I to Mode II. • Fatigue limit design for the punching processed plate was coarse-grained. Abstract It is well known that the fatigue limits of some precipitation-hardened steels with a punched hole do not increase, even if the tensile strengths of base-metal increases. This study suggested that the dominant reason for this strange phenomenon is a transition from the Mode I type fatigue crack propagation due to the cyclic plastic deformation to Mode II type propagation due to the damage accumulation by a quantitative analysis of influential factors based on fracture mechanics. This result can open a probability that the fatigue limit of the punched hole with shear-affected zone can be actively quantified. [ABSTRACT FROM AUTHOR]

Purpose: The developmental status of the male and female spike determines grain number (GN) per ear and yield. A better understanding of the effect of N on male and female spike differentiation and GN formation could help to gain insight into the mechanism of N regulation on yield. Methods: A field experiment was conducted with four nitrogen rates: 0 (N0), 129 (N1), 185 (N2), and 300 kg N ha−1 (N3) with a single summer maize hybrid to determine tassel and ear development and the resulting GN. Results: The expression of key proteins and genes related to fatty acid metabolism of N0 were down-regulated and the tapetum was abnormally degraded. This inhibited the synthesis of long-chain fatty acids (LCFAs) in the tassel and ear. Both pollen and silk development at the mononucleate stage were abnormal and presented as misshapen pollen, uneven silk tube, reduced silk, and poor pollination. Finally, anthesis-silking interval (ASI) was increased and the length of male and female spikes, fertilized florets, floret fertility percentage, and grain set rate were reduced in N0 treatment resulting in reduced GN. N application promoted fatty acid metabolism but N application greater than 185 kg N ha−1 did not increase LCFA of either male or female spike traits. Conclusions: A nitrogen rate of 185 kg N ha−1 was sufficient to promote lipid metabolism, and increase the content of LCFAs. This resulted in normal pollen and silk development, shortened ASI and led to an increase in the number of fertile florets, fertilization percentage, and GN. [ABSTRACT FROM AUTHOR]

In order to improve the brittle characteristics of coral cement-based composites and increase their toughness, an experimental study was carried out on the basic mechanical properties of PVA (polyvinyl alcohol) fiber-reinforced coral cement-based composites, taking into account the fiber content and length-to-diameter ratio (L/D). The results showed that PVA fibers can effectively improve the mechanical properties of concrete, especially its tensile strength. At the same time, PVA fibers improved the damage characteristics of cement-based composites and had obvious toughening and brittleness reduction effects. The PVA fibers, with a volume content of 1.5% and an L/D of 225, had the best performance in reinforcing the overall performance of the coral cement-based composites. Too many PVA fibers or a large length-to-diameter ratio would make it difficult for the fibers to contribute to toughness and cracking resistance and even cause defects in the matrix, reducing the mechanical properties. The tensile stress-strain curves of PVA fiber-reinforced coral cement-based composites were consistent with the trilinear constitutive model curves and showed the tensile characteristic of strain hardening after the occurrence of the main cracks. [ABSTRACT FROM AUTHOR]

Corn-peanut intercropping is an important element of China's agricultural planting model as it confers ecological benefits and increases yield. The aim of this study was to explore the productivity differences between intercropping and monoculture by using the 13C isotope tracer labelling method. Corn hybrid Denghai 618 (DH618) and peanut variety Huayu 22 (HY22) were used as test materials under three planting methods, single corn, SM; single peanut, SP; and corn-peanut intercropping, IM and IP, respectively, during two growing seasons. The results showed that IM increased yield by 59.7% and 62.3% compared with SM, respectively. IP reduced yield by 31.3% and 32.3% compared with SP, respectively. IM significantly increased the photosynthetic rate, leaf area, 13C assimilation distribution, and dry matter accumulation of summer corn, which led to an increase in the kernel number and grain yield. The decrease in intercropped peanut yield was mainly caused by a decrease in the full-pod rate and number of pods per plant. The decrease in peanut yield did not affect the production of intercropping benefit due to the larger intercropping advantage and land equivalence ratio. Corn-peanut intercropping yielded greater economic benefits than monoculture. These results showed the utility of the peanut-corn intercropping model. [ABSTRACT FROM AUTHOR]

Background: Soil salt stress is a problem in the world, which turns into one of the main limiting factors hindering maize production. Salinity significantly affects root physiological processes in maize plants. There are few studies, however, that analyses the response of maize to salt stress in terms of the development of root anatomy and respiration. Results: We found that the leaf relative water content, photosynthetic characteristics, and catalase activity exhibited a significantly decrease of salt stress treatments. However, salt stress treatments caused the superoxide dismutase activity, peroxidase activity, malondialdehyde content, Na+ uptake and translocation rate to be higher than that of control treatments. The detrimental effect of salt stress on YY7 variety was more pronounced than that of JNY658. Under salt stress, the number of root cortical aerenchyma in salt-tolerant JNY658 plants was significantly higher than that of control, as well as a larger cortical cell size and a lower root cortical cell file number, all of which help to maintain higher biomass. The total respiration rate of two varieties exposed to salt stress was lower than that of control treatment, while the alternate oxidative respiration rate was higher, and the root response of JNY658 plants was significant. Under salt stress, the roots net Na+ and K+ efflux rates of two varieties were higher than those of the control treatment, where the strength of net Na+ efflux rate from the roots of JNY658 plants and the net K+ efflux rate from roots of YY7 plants was remarkable. The increase in efflux rates reduced the Na+ toxicity of the root and helped to maintain its ion balance. Conclusion: These results demonstrated that salt-tolerant maize varieties incur a relatively low metabolic cost required to establish a higher root cortical aerenchyma, larger cortical cell size and lower root cortical cell file number, significantly reduced the total respiration rate, and that it also increased the alternate oxidative respiration rate, thereby counteracting the detrimental effect of oxidative damage on root respiration of root growth. In addition, Na+ uptake on the root surface decreased, the translocation of Na+ to the rest of the plant was constrained and the level of Na+ accumulation in leaves significantly reduced under salt stress, thus preempting salt-stress induced impediments to the formation of shoot biomass. [ABSTRACT FROM AUTHOR]

The family of ten-eleven translocation dioxygenases (TETs) consists of TET1, TET2, and TET3. Although all TETs are expressed in hematopoietic tissues, only TET2 is commonly found to be mutated in age-related clonal hematopoiesis and hematopoietic malignancies. TET2 mutation causes abnormal epigenetic landscape changes and results in multiple stages of lineage commitment/differentiation defects as well as genetic instability in hematopoietic stem/progenitor cells (HSPCs). TET2 mutations are founder mutations (first hits) in approximately 40–50% of cases of TET2-mutant (TET2MT) hematopoietic malignancies and are later hits in the remaining cases. In both situations, TET2MT collaborates with co-occurring mutations to promote malignant transformation. In TET2MT tumor cells, TET1 and TET3 partially compensate for TET2 activity and contribute to the pathogenesis of TET2MT hematopoietic malignancies. Here we summarize the most recent research on TETs in regulating of both normal and pathogenic hematopoiesis. We review the concomitant mutations and aberrant signals in TET2MT malignancies. We also discuss the molecular mechanisms by which concomitant mutations and aberrant signals determine lineage commitment in HSPCs and the identity of hematopoietic malignancies. Finally, we discuss potential strategies to treat TET2MT hematopoietic malignancies, including reverting the methylation state of TET2 target genes and targeting the concomitant mutations and aberrant signals. [ABSTRACT FROM AUTHOR]

Introduction: Splice modulators have been assessed clinically in treating haematologic malignancies exhibiting splice factor mutations and acute myeloid leukaemia. However, the mechanisms by which such modulators repress leukaemia remain to be elucidated.Objectives: The primary goal of this assessment was to assess the molecular mechanism by which the natural splice modulator GEX1A kills leukaemic cells in vitro and within in vivo mouse models.Methods: Using human leukaemic cell lines, we assessed the overall sensitivity these cells have to GEX1A via EC50 analysis. We subsequently analysed its effects using in vivo xenograft mouse models and examined whether cell sensitivities were correlated to genetic characteristics or protein expression levels. We also utilised RT-PCR and RNAseq analyses to determine splice change and RNA expression level differences between sensitive and resistant leukaemic cell lines.Results: We found that, in vitro, GEX1A induced an MCL-1 isoform shift to pro-apoptotic MCL-1S in all leukaemic cell types, though sensitivity to GEX1A-induced apoptosis was negatively associated with BCL-xL expression. In BCL-2-expressing leukaemic cells, GEX1A induced BCL-2-dependent apoptosis by converting pro-survival BCL-2 into a cell killer. Thus, GEX1A + selective BCL-xL inhibition induced synergism in killing leukaemic cells, while GEX1A + BCL-2 inhibition showed antagonism in BCL-2-expressing leukaemic cells. In addition, GEX1A sensitised FLT3-ITD+ leukaemic cells to apoptosis by inducing aberrant splicing and repressing the expression of FLT3-ITD. Consistently, in in vivo xenografts, GEX1A killed the bulk of leukaemic cells via apoptosis when combined with BCL-xL inhibition. Furthermore, GEX1A repressed leukaemia development by targeting leukaemia stem cells through inhibiting FASTK mitochondrial isoform expression across sensitive and non-sensitive leukaemia types.Conclusion: Our study suggests that GEX1A is a potent anti-leukaemic agent in combination with BCL-xL inhibitors, which targets leukaemic blasts and leukaemia stem cells through distinct mechanisms. [ABSTRACT FROM AUTHOR]

The ten–eleven translocation (TET) family of dioxygenases consists of three members, TET1, TET2, and TET3. All three TET enzymes have Fe+2 and α-ketoglutarate (α-KG)-dependent dioxygenase activities, catalyzing the 1st step of DNA demethylation by converting 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), and further oxidize 5hmC to 5-formylcytosine (5fC) and 5-carboxylcytosine (5caC). Gene knockout studies demonstrated that all three TET proteins are involved in the regulation of fetal organ generation during embryonic development and normal tissue generation postnatally. TET proteins play such roles by regulating the expression of key differentiation and fate-determining genes via (1) enzymatic activity-dependent DNA methylation of the promoters and enhancers of target genes; and (2) enzymatic activity-independent regulation of histone modification. Interacting partner proteins and post-translational regulatory mechanisms regulate the activities of TET proteins. Mutations and dysregulation of TET proteins are involved in the pathogenesis of human diseases, specifically cancers. Here, we summarize the research on the interaction partners and post-translational modifications of TET proteins. We also discuss the molecular mechanisms by which these partner proteins and modifications regulate TET functioning and target gene expression. Such information will help in the design of medications useful for targeted therapy of TET-mutant-related diseases. [ABSTRACT FROM AUTHOR]

Our understanding of MM genomics has expanded rapidly in the past 5–10 years as a consequence of cytogenetic analyses obtained in routine clinical practice as well as the ability to perform whole-exome/genome sequencing and gene expression profiling on large patient data sets. This knowledge has offered new insights into disease biology and is increasingly defining high-risk genomic patterns. In this manuscript, we present a thorough review of our current knowledge of MM genomics. The epidemiology and biology of chromosomal abnormalities including both copy number abnormalities and chromosomal translocation are described in full with a focus on those most clinically impactful such as 1q amplification and del(17p) as well as certain chromosome 14 translocations. A review of our ever-expanding knowledge of genetic mutations derived from recent whole-genome/exome data sets is then reviewed including those that drive disease pathogenesis from precursor states as well as those that may impact clinical outcomes. We then transition and attempt to elucidate how both chromosomal abnormalities and gene mutations are evolving our understanding of disease risk. We conclude by offering our perspectives moving forward as to how we might apply whole-genome/exome-level data in addition to routine cytogenetic analyses to improve patient outcomes as well as further knowledge gaps that must be addressed. [ABSTRACT FROM AUTHOR]

Cytokinin is known to be involved in the regulation of plant responses to counteract the adverse effects of stress conditions. This work investigated the effects of exogenous spraying of 6-benzyladenine (6-BA) after water logging for 6 days at the third leaf stage (V-3WL + BA) and the sixth leaf stage (V-6WL + BA) on grain yield and growth of summer maize hybrids DengHai605 (DH605) and ZhengDan958 (ZD958), which are planted most popularly in China. Waterlogging under field conditions delayed the growth process, decreased leaf area index, chlorophyll content and dry matter accumulation, resulted in a significant reduction of grain yield with a decrease of 30.30% and 18.78% under V-3WL (water logging for 6 days at the third leaf stage) and V-6WL (waterlogging for 6 days at the sixth leaf stage) of DH605, 30.39% and 21.38% under V-3WL and V-6WL of ZD958, respectively, compared to the control (CK). By contrast, exogenous application of 6-BA effectively alleviated the adverse effects of waterlogging on summer maize by delaying leaf senescence, increasing chlorophyll content and improving photosynthetic performance. At tasseling stage, the P n of V-3WL + BA and V-6WL + BA in DH605 increased by 9.57% and 8.38%, respectively, compared to that of V-3WL and V-6WL, while the corresponding values for ZD958 increased by 2.96% and 4.05%, respectively. Those responses are conducive to the accumulation of photosynthetic products, increasing grain filling rate, and improving ear character, and then leading to increase grain yield of summer maize. Grain yield of DH605 under V-3WL + BA and V-6WL + BA increased by 15.57% and 12.39%, respectively, compared to that of V-3WL and V-6WL, while the corresponding values for ZD958 increased by 20.05% and 15.32%, respectively. Clearly, spraying exogenous 6-BA could effectively improve grain-filling characteristics and photosynthesis of waterlogged summer maize, resulting in a significant increase of grain yield, compared to water logging treatments. [ABSTRACT FROM AUTHOR]

• Vanadium addition causes an increase in both yield strength and yield ratio. • Vanadium addition reduces strain hardening ability, and weakens wear resistance. • RCF crack initiation of V-alloyed stee is delayed by increasing yield strength. • RCF crack growth size is restricted by reducing plastic deformation capacity. • Increasing yield ratio improves RCF resistance, but weakens wear resistance. This study aims to evaluate the effect of vanadium microalloying on rolling contact fatigue (RCF) and wear behavior of railway wheel steels. It involves microstructural analysis and mechanical testing, including hardness, tensile, and rolling/sliding tests on the test steels, followed by electron backscatter diffraction, residual stress, and microhardness analyses after rolling/sliding tests. The findings demonstrate that vanadium microalloying leads to the alleviation of dynamic recrystallization, strain hardening, and compressive residual stress within the outermost layer beneath the worn surface, indicating a reduction in the plastic deformation capacity during dry rolling/sliding conditions. RCF resistance of railway steel can be enhanced through vanadium microalloying, as it simultaneously delays crack initiation by increasing yield strength and restricts crack growth by reducing plastic deformation capacity. While vanadium microalloying enhances the matrix hardness of wheel steel, it concurrently diminishes its strain hardening ability, potentially compromising its wear resistance. In addition, this study found that the yield ratio, being indicative of plastic deformation capacity and strain hardening ability, can serve as a suitable parameter for characterizing the RCF and wear resistances of tested steels. It exhibits a positive correlation with RCF resistance and a negative correlation with wear resistance. [ABSTRACT FROM AUTHOR]

High temperature superconducting (HTS) maglev transportation has provided a new development direction for high-speed and ultra-high-speed rail transit. In order to promote the development of HTS materials in this area, the dynamic response of the vehicle superconductor under an alternating magnetic field with high frequency is well-worth studying. However, limited by some experimental conditions and other factors, the effective modelling method becomes an indispensable and cost-effective tool to predict the electromagnetic properties of the superconductors. In this paper, based on the single-peaked permanent magnet guideway (PMG)-HTS bulks maglev configuration, the modelling using three different E-J relationships include the power law model (PLM), the flux flow and creep model (FFCM), and the flux flow model (FFM) are compared. Results indicate that the PLM has the highest computational efficiency and good reliability. Then, using the PLM, we further study the dynamic response of the HTS bulks over a Halbach-typed PMG under higher vibration frequencies. The effect of the magnet failure in the middle of the PMG on the levitation system is also discussed. A finite element method is applied with the H formulation. The moving mesh is used to realize the relative displacement between the PMG and HTS bulks. To investigate the temperature rise and the AC loss inside the HTS bulks, the Heat Transfer module is coupled. Results show that the temperature inside the HTS bulks will decay exponentially with time if the magnitude and frequency of the external magnetic field do not continue to increase. This work can provide some references for the future practical applications of the high-speed HTS maglev. [ABSTRACT FROM AUTHOR]

Aims: To realize the so-called "Second Green Revolution", it is imperative to study the roots of crop plants, and identify those traits that improve the efficiency of nitrogen (N) acquisition. We aimed to evaluate how the N acquisition efficiency of six hybrid maize lines commonly grown in northern China depends on their root anatomy. Methods: Maize hybrids classified as having high nitrogen uptake efficiency (HNUE) and low nitrogen uptake efficiency (LNUE) were grown under high-N and low-N conditions in the greenhouse and the field. Results: Under N stress in the field and the greenhouse, HNUE increased shoot dry weight, root length density, N content and nitrogen use efficiency compared to LNUE. Low N availability increased the percentage of root cortical aerenchyma and the size of cortical cells. Root anatomy, with greater formation of root cortical aerenchyma and larger cortical cell size, was associated with increased specific nitrogen absorption efficiency (SNAE) and shoot biomass under N stress. Under low N availability, the percentage of aerenchyma and their total area had significant positive correlations with the shoot dry weight, total N uptake, SNAE. Conclusions: The results suggest that plants in limited N availability form more root cortical aerenchyma and have larger cortical cells, which is of benefit to root growth, soil exploration, N acquisition, and shoot biomass. These observations support the hypothesis that root anatomical phenotypes that affect the metabolic and construction costs of producing root length merit consideration as selection criteria for breeding to improve N acquisition in hybrid maize. [ABSTRACT FROM AUTHOR]