Peroxiredoxins (PRDXs), a ubiquitous family of redox‐regulating proteins, are reported of potential to eliminate various reactive oxygen species (ROS). As a major member of the antioxidant enzymes, ...PRDX1 can become easily over‐oxidized on its catalytically active cysteine induced by a variety of stimuli in vitro and in vivo. In nucleus, oligomeric PRDX1 directly associates with p53 or transcription factors such as c‐Myc, NF‐κB and AR, and thus affects their bioactivities upon gene regulation, which in turn induces or suppresses cell death. Additionally, PRDX1 in cytoplasm has anti‐apoptotic potential through direct or indirect interactions with several ROS‐dependent (redox regulation) effectors, including ASK1, p66Shc, GSTpi/JNK and c‐Abl kinase. PRDX1 is proven to be a versatile molecule regulating cell growth, differentiation and apoptosis. Recent studies have found that PRDX1 and/or PRDX1‐regulated ROS‐dependent signalling pathways play an important role in the progression and metastasis of human tumours, particularly in breast, oesophageal and lung cancers. In this paper, we review the structure, effector functions of PRDX1, its role in cancer and the pivotal role of ROS in anticancer treatment.
Abstract
Integral thin shells made of high strength aluminum alloys are urgently needed in new generation transportation equipment. There are challenges to overcoming the co-existing problems of ...wrinkling and splitting by the cold forming and hot forming processes. An innovative technology of ultra-low temperature forming has been invented for aluminum alloy thin shells by the new phenomenon of ‘dual enhancement effect’. That means plasticity and hardening are enhanced simultaneously at ultra-low temperatures. In this perspective, the dual enhancement effect is described, and the development, current state and prospects of this new forming method are introduced. This innovative method can provide a new approach for integral aluminum alloy components with large size, ultra-thin thickness, and high strength. An integral tank dome of rocket with 2 m in diameter was formed by using a blank sheet with the same thickness as the final component, breaking through the limit value of thickness-diameter ratio.
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•A novel process of pre-aging blanks before friction stir welding was proposed to prepare tailor-welded blank with superior ductility, microstructure, and strength ...simultaneously.•Abnormal grain growth was avoided through an innovate design of pre-aging blanks before welding.•The effect of rotational speeds on the microstructure and mechanical property was systematically analyzed to obtain an optimal welding parameter.•The strengthening mechanisms of pre-aging friction stir welded blanks was revealed through microstructure characterization and Vickers’ hardness measurements.
Achieving superior ductility, microstructure, and strength simultaneously in tailor-welded blanks remains challenging. To address this, pre-aging blanks before friction stir welding was proposed. Systematic studies were conducted on the microstructure, ductility, and post-aging strength of pre-aged 2219 aluminium alloy after friction stir welding. Uniaxial tensile tests evaluated the ductility of tailor-welded blanks at room and cryogenic temperatures, along with their mechanical properties after artificial aging. Microstructural characterization and Vickers hardness measurements elucidated the strengthening mechanisms between the welded region and base material. No abnormal grain growth was observed in the welded region post pre-aging welding; instead, a finer grain structure prevailed. Ductility of the tailor-welded blanks initially increased and then decreased with increasing rotational speed. Excellent elongations, 27.8% at room temperature and 32.4% at cryogenic temperatures, were obtained at a rotational speed of 1300 rpm, reaching 91.5% of the base material. This attributed to the finer grain boundary strengthening in the welded regions. After artificial aging, a joint efficiency of 93.5% was achieved, owing to effective compensation of the reduction in precipitation strengthening caused by the welded heat input through finer grain strengthening. This approach represents a novel method for preparing ultrawide blanks for forming integral large-sized aluminum alloy components.
The hybridization chain reaction (HCR) is widely used for biosensing. However, HCR does not provide the required sensitivity. In this study, we reported a method to improve the sensitivity of HCR by ...dampening the cascade amplification. First, we designed a biosensor based on HCR, and an initiator DNA was used to trigger the cascade amplification. Optimization of the reaction was then performed, and the results showed that the limit of detection (LOD) for the initiator DNA was about 2.5 nM. Second, we designed a series of inhibitory DNAs to dampen the HCR cascade amplification, and DNA dampeners (50 nM) were applied in the presence of the DNA initiator (50 nM). One of the DNA dampeners (D5) showed the best inhibitory efficiency of greater than 80%. This was further applied at concentrations ranging from 0 nM to 10 nM to prohibit the HCR amplification caused by a 2.5 nM initiator DNA (the limit of detection for this initiator DNA). The results showed that 0.156 nM of D5 could significantly inhibit the signal amplification (p<0.05). Additionally, the limit of detection for the dampener D5 was 16 times lower than that for the initiator DNA. Based on this detection method, we achieved a detection limit as low as 0.625 nM for HCV-RNAs. In summary, we developed a novel method with improved sensitivity to detect the target designed to prohibit the HCR cascade. Overall, this method could be used to qualitatively detect the presence of single-stranded DNA/RNA.
New manufacturing technology for light-weight structure materials has been used to meet the requirements for weight reduction and safety performance. In this paper, the hot forming-quenching ...integrated process of 6A02 aluminum alloy sheet at different forming-dies temperatures ranging from 50°C to 350°C was investigated. Vickers hardness test and uniaxial tensile test were carried out to reveal the strengthening behavior. Microstructure evolution was observed to clarify the strengthening mechanism with electron backscattering diffraction (EBSD), transmission electron microscopy (TEM) and scanning electron microscope (SEM) methods. Results show that the Vickers hardness and tensile strength decreased with increasing forming-dies temperature. No obvious decrease in strength appeared until the forming-dies temperature reached 250°C. The corresponding Vickers hardness was increased to 100.6 HV from original 73 HV in rolled condition, and the tensile and yield strengths were 303.8MPa and 257.1MPa, respectively. When the temperature of forming-dies rose to 350°C, the tensile and yield strengths dropped to 270.1MPa and 213.7MPa, respectively. The strengthening phase in Al matrix was the dispersed needle-shaped β″ precipitates with size about 10−50nm. Transformation of the rod-shaped β′ precipitates with 150–300nm in size at the grain boundaries and in grain interiors led to the decrease in strength. The forming-dies temperature should not be higher than 250°C for the integrated forming of 6A02 aluminum alloy sheet to obtain enough strengthening effect.
As important light-weight structure material, aluminum alloy has been widely used in automotive and aerospace industries, in which the manufacturing of parts with high strength and good dimensional ...accuracy has been the main task. In this paper, special device was developed to investigate the hot forming–quenching integrated process of cold-rolled 6A02 aluminum alloy sheet. Strengthening effect was reflected by Vickers hardness measuring and uniaxial tensile test. Microstructure examination was conducted to clarify the strengthening mechanism by scanning electron microscope (SEM), transmission electron microscopy(TEM) and electron backscattering diffraction (EBSD). Results show that Vickers hardness increases with solution time (<50min) increase, and improves significantly after artificial aging. The faster the cooling rate, the greater the strengthening effect. The Vickers hardness of formed part can increase to 106.5HV from 73HV in cold-rolled condition or 40HV in heated condition in hot forming–quenching integrated process (solution treatment at 520°C/50min, cooling by 50°C/s, being aged at 160°C/10h). The corresponding tensile strength and yield strength are 315.6MPa and 253.6MPa, respectively. The strengthening phase is underaged dispersal GP zone with about 5nm in size. The heat-treatable aluminum alloy sheet in rolled condition can be used directly in hot forming–quenching integrated process without any prophase heat treatment.
Cables are the main load-bearing components of a cable bridge and typically composed of high strength steel wires with a galvanized coating or Galfan coating. Galfan steel wire has recently started ...to be widely used because of its better corrosion resistance than galvanized steel wire. The corrosion characteristics of the coating and the difference in the corrosion fatigue process of the two types of steel wire are unclear. To further improve the service performance and maintenance of cable bridges, this study investigated the corrosion characteristics of galvanized steel wire and Galfan steel wire through accelerated corrosion tests and established a time-varying model of uniform corrosion and pitting corrosion of high-strength steel wire. Then, a long-span suspension bridge was taken as the research object, and the corrosion fatigue degradation of the two kinds of steel wire under a traffic load was analyzed on the basis of traffic monitoring data. The results showed that the uniform corrosion of the two types of steel wire conformed to an exponential development trend, the corrosion coefficient of galvanized steel wire conformed to the normal distribution, and the corrosion coefficient of Galfan steel wire conformed to the Cauchy distribution. The maximum pitting coefficient distribution of the two kinds of steel wire conformed to the generalized extreme value distribution. The location parameters and scale parameters of the two distributions showed an exponential downward trend with the increase of corrosion duration. When the traffic intensity was low, the corrosion characteristics of the steel wire was the main factor affecting its service life, and the average service life of Galfan steel wire was significantly higher than that of galvanized steel wire. Under a dense traffic flow, the service life of the steel wire was mainly controlled by the traffic load, and the service life of Galfan steel wire was slightly improved. Effective anti-corrosion measures are a key factor for improving the service life of steel wire.
Hot gas forming with an integrated heat treatment was utilized to form complex-shaped components in one operation that obtain full strength. The effects of the pressurizing rate on the deformation ...and strengthening behaviors were critical. Free-bulging tests were conducted at different pressurizing rates (0.0088–2.37 MPa/s) to reveal the corresponding deformation and strengthening behaviors of an Al–Cu–Li alloy sheet and for choosing appropriate pressurizing conditions. The profile and thickness were analyzed to describe the deformation behaviors. The Vickers hardness under different pressurizing and deformation conditions was measured to evaluate the strengthening behavior. The microstructure evolution was observed to reveal the deformation and strengthening mechanisms. An excellent bulging ability was obtained under the full solution condition, with a maximum strain of 0.88 at a pressurizing rate of 0.034 MPa/s. The thickness distribution became more uniform under rapid pressurizing conditions because of the increasing strain and strain-rate hardening abilities. The hardness increased with increasing deformation and was not affected by the pressurizing rate. Dynamic recovery was the main deformation mechanism, and dynamic recrystallization occurred at a low pressurizing rate. Fine precipitates comprising the T
1
phase (Al
2
CuLi, hexagonal structure) were the main strengthening phase. The pressurizing condition was only considered to obtain the maximum improvement in formability and microstructure, regardless of its effect on strengthening during hot gas forming with an integrated heat treatment.
The thin-walled curved-surface component is an important structural element in aerospace. Wrinkling, springback and thermal distortion occur easily when forming these components. To form thin-walled ...components with high precision and strength, a two-layer-sheet hot-forming-quenching integrated process was proposed, in which wrinkling is prevented by thickening the upper sheet and springback is reduced by solution and die quenching. Selecting an appropriate upper sheet is crucial to suppress wrinkling and accomplish effective die quenching. The effect of the upper sheet on the wrinkling and strengthening behaviors of an Al-Cu-Mg-alloy melon-petal shell was thus studied in detail. The anti-wrinkle mechanism was analyzed through numerical simulation. The forming quality, including forming precision, deformation uniformity and strength, were further evaluated. The wrinkle gradually decreased with the increasing thickness of the upper sheet, resulting from the depressed compressive stress at the edge of the target sheet. A defect-free specimen with a smooth surface was finally formed when the thickness of the upper sheet reached three times that of the target sheet. The profile deviation was ±0.5 mm. Excellent thickness uniformity in a specimen can be obtained with a maximum thinning rate of 6%. The full strength, ranging from 455 to 466 MPa, can be obtained in all regions of the specimen, indicating that effective strengthening can be accomplished with the two-layer-sheet die quenching. The results indicated that high forming quality and full strength can be obtained in a two-layer-sheet hot-forming-quenching integrated process. This research has great potential for engineering applications using aluminum-alloy curved-surface thin-walled components.
An effective biomarker for the diagnosis of breast cancer (BC) and benign breast diseases (BBD) is crucial for improving the prognosis. We investigated whether N6-methyladenosine (m6A) can be a ...diagnostic biomarker of BC.
We detected the contents of peripheral blood m6A in 62 patients with BC, 41 patients with BBD, and 41 normal controls (NCs) using the colorimetric method. The relative expression of the m6A regulated genes methyltransferase-like 14 (METTL14) and fat mass and obesity-associated (FTO) was analyzed using quantitative real-time polymerase chain reaction.
m6A in peripheral blood RNA was significantly higher in patients with BC than that in patients with BBD (p < 0.001) or the NCs (p < 0.001). m6A was closely associated with the disease stage (from stage 0 to stage I-IV, p=0.003). The receiver operating characteristic curve of m6A contained an area under the curve (AUC) value of 0.887 in BC, which was greater than that of carcinoembryonic antigen (CEA) or carbohydrate antigen 153 (CA153). The combination of m6A, CEA, and CA153 improved the AUC to 0.914. The upregulated and downregulated mRNA expression of METTL14 and FTO, respectively, might contribute to the increase of m6A in patients with BC. m6A combined with METTL14 and FTO improved the AUC to 0.929 with a specificity of 97.4% in the peripheral blood of patients with BC.
The peripheral blood RNA of m6A might be a valuable biomarker for the diagnosis of BC.
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