Search

Abstract Background Aging of the male prostate is an inevitable process in which the prostate undergoes hyperplasia, and this growth may lead to compression of the urethra, resulting in voiding dysfunction and associated symptoms, and an increased risk of prostate cancer. Despite the significance of prostate aging, the molecular mechanisms involved are still not fully understood. Methods Prostate split by lobes from young (2 months) and aged (24 months) mice were collected for single-cell RNA sequencing (scRNA-seq) analysis. Tissues from both anterior prostate (AP) and ventral/dorsal/lateral prostate (VDLP) were included in the study. Data analysis included unsupervised clustering using the uniform manifold approximation and projection (UMAP) algorithm to identify distinct cell types based on marker gene expression. Differential gene expression analysis was performed to identify age-related changes in gene expression across different cell types. Functional enrichment analysis was conducted to elucidate biological pathways associated with differentially expressed genes. Additionally, cellular interactions and developmental trajectories were analyzed to characterize cellular dynamics during prostate aging. Results The single-cell transcriptome analysis of the mouse prostate during aging revealed heterogeneity across various cell types and their changes during the aging process. We found a significant increase in the proportion of mesenchymal and immune cells in aged mice. Our study unveiled alterations in genes and pathways associated with cellular senescence, oxidative stress, and regeneration in epithelial cells. Furthermore, we observed that basal cells may undergo epithelial-mesenchymal transition (EMT) to become mesenchymal cells, particularly prominent in aged mice. Additionally, immune cells, notably macrophages and T cells, exhibited a heightened inflammatory response in aged mice. Conclusion In summary, our study provides a comparative analysis of the single-cell transcriptome of the aged and young mice prostates, elucidating cellular and molecular changes between the aged and young mice prostates.

The instability of plastic flow in medium manganese steel was investigated through uniaxial tensile tests conducted at room temperature across various strain rates. The Portvin-Le Chatelier (PLC) effect was analyzed using statistical methods and a multifractal approach. The findings indicate that the zigzag stress–strain curves associated with instability plastic flow exhibit typical multifractal characteristics. Furthermore, the multifractal analysis quantifies the influence of strain rate and initial phase composition on the instability characteristics of the stress–strain curves. Specifically, it was observed that lower strain rates and austenite content correspond to a chaotic state, whereas higher strain rates and austenite content result in self-organizing critical dynamics. Finally, the underlying physical mechanisms driving these differing modes of behavior are discussed, with a focus on their relationship to strain rate and the initial austenitic phase fraction.

QP (Quenching and Partitioning) steel, the third generation of advanced high-strength steel, has garnered significant attention due to its exceptional mechanical performance. This paper investigates the interplay of grain rotation, slip transfer, and back stress strengthening through quasi in-situ deformation scanning electron microscope (SEM), electron backscatter diffraction (EBSD), and load-unload-reload (LUR) cycle tests. The findings reveal the substantial differences between QP980 and QP1180. QP980, characterized by heterostructures, exhibits non-uniform deformation characteristics. In regions with heterostructures, grain rotation inhibits slip transfer, leading to the accumulation of geometrically necessary dislocations (GNDs) and the formation of dislocation substructures (walls and cells), resulting in significant back stress strengthening. Conversely, due to the lack of heterogeneous structural regions, QP1180 displays uniform deformation characteristics, grain rotation and slip transfer promote each other, showing a weaker and different back stress strengthening compared to QP980. The interplay of grain rotation, slip transmission, and dislocation substructure formation influences the back stress behavior, impacting the mechanical properties and deformation behavior of the materials. This research provides a novel perspective on plastic deformation and strengthening theory, and serves as a valuable reference for material design and performance optimization.

ObjectiveInvestigating the causal relationship between Lachnospiraceae and Appendicular lean mass (ALM) and identifying and quantifying the role of Aminopeptidase O Protein (AOPEP) as a potential mediator.MethodsThe summary statistics data of gut microbiota composition from the largest available genome-wide association study (GWAS) meta-analysis conducted by the MiBioGen Consortium (n = 13,266). Appendicular lean mass data were obtained from the UK-Biobank (n = 450,243). We conducted bidirectional two-sample Mendelian randomization (MR) analysis using summary-level data from GWAS to investigate the causal relationship between Lachnospiraceae and ALM. Additionally, we employed a drug-targeted MR approach to assess the causal relationship between AOPEP and ALM. Finally, a two-step MR was employed to quantitatively estimate the proportion of the effect of Lachnospiraceae on ALM that is mediated by AOPEP. Cochran's Q statistic was used to quantify heterogeneity among instrumental variable estimates.ResultsIn the MR analysis, it was found that an increase in genetically predicted Lachnospiraceae [OR = 1.031, 95% CI (1.011–1.051), P = 0.002] is associated with an increase in ALM. There is no strong evidence to suggest that genetically predicted ALM has an impact on Lachnospiraceae genus [OR = 1.437, 95% CI (0.785–2.269), P = 0.239]. The proportion of genetically predicted Lachnospiraceae mediated by AOPEP was 34.2% [95% CI (1.3%−67.1%)].ConclusionOur research reveals that increasing Lachnospiraceae abundance in the gut can directly enhance limb muscle mass and concurrently suppress AOPEP, consequently mitigating limb muscle loss. This supports the potential therapeutic modulation of gut microbiota for sarcopenia. Interventions such as drug treatments or microbiota transplantation, aimed at elevating Lachnospiraceae abundance and AOPEP inhibition, synergistically improve sarcopenia in the elderly, thereby enhancing the overall quality of life for older individuals.

The objective of the present research is to investigate the influence of the microstructural evolution mechanism on mechanical properties during deformation. For this purpose, hot rolled Fe-0.22C-6.12Mn-3.08Al steel is subjected to intercritical annealing at 740 °C for 10 min. The annealed specimen contains a mixture of lath-like α-ferrite and reverted γ, whose volume fraction is approximately 38.7%. During deformation, once the critical stress caused by the severe dislocation pile-ups is reached, the strain/stress-induced phase transformation occurs. First, grain boundaries of γ/α serve as the preferential nucleation sites for fresh α′-martensite. Subsequently, fresh α′-martensite nucleates inside reverted γ. In the meantime, the interfacial α′-martensite grows continuously into the reverted γ interior. During deformation (prestrain at 0.0%, 5.1% and 7.8%), the misorientation (MO) in α-ferrite+α′-martensite continuously rises from 0.63° to 0.67°; nevertheless, the MO in reverted γ increases from 0.65° to 0.73° and then rapidly decreases to 0.69°. Hence, the phase transformation of reverted γ is accompanied by obvious stress softening; thus, effective work hardening occurs in the subsequent deformation region due to α-ferrite and fresh α′-martensite. This phenomenon greatly enhances the strength and delays necking, e.g., the annealed specimen possesses outstanding mechanical properties (992 MPa, 47.6% and 47.2 GPa × %). Once necking occurs, the residual reverted γ is rapidly consumed in the necking region. Hence, the hardness in the necking region (5.31 ± 0.20 GPa) is much higher than that in the uniform deformation region (4.53 ± 0.17 GPa) due to the abundant hard fresh α′-martensite.

Recently, there has been a new trend to design chemically heterogeneous austenite by adjusting the various thermal treatment processes in medium Mn steel. In this work, we found that the single or synergistic addition of ferrite stabilizers (e.g., Al) accelerated the heterogeneous distribution of Mn and the formation of a core-shell austenitic structure compared with the addition of an austenite stabilizer (e.g., Cu) under the conventional quenched-annealing process. In addition, the Mn-enriched austenite shell played a significant role in suppressing the martensitic transformation of the Mn-depleted austenite core upon cooling. The sharp Mn gradient distribution corresponded to the heterogeneous kinetics of the deformation-induced martensitic transformation, resulting in the gradual transformation-induced plasticity (TRIP) effect.

Background Artificial intelligence (AI) technologies are transforming medicine and healthcare. Scholars and practitioners have debated the philosophical, ethical, legal, and regulatory implications of medical AI, and empirical research on stakeholders’ knowledge, attitude, and practices has started to emerge. This study is a systematic review of published empirical studies of medical AI ethics with the goal of mapping the main approaches, findings, and limitations of scholarship to inform future practice considerations. Methods We searched seven databases for published peer-reviewed empirical studies on medical AI ethics and evaluated them in terms of types of technologies studied, geographic locations, stakeholders involved, research methods used, ethical principles studied, and major findings. Findings Thirty-six studies were included (published 2013-2022). They typically belonged to one of the three topics: exploratory studies of stakeholder knowledge and attitude toward medical AI, theory-building studies testing hypotheses regarding factors contributing to stakeholders’ acceptance of medical AI, and studies identifying and correcting bias in medical AI. Interpretation There is a disconnect between high-level ethical principles and guidelines developed by ethicists and empirical research on the topic and a need to embed ethicists in tandem with AI developers, clinicians, patients, and scholars of innovation and technology adoption in studying medical AI ethics.

Liquefying hydrogen is an efficient way to store and transport hydrogen. However, the hydrogen liquefaction process is energy intensive. Therefore, an integrated liquefaction process of hydrogen and natural gas utilizing the mixed refrigerant cycle and the hydrogen Claude cycle is proposed. The process not only couples a steam methane reforming process to produce hydrogen and a carbon dioxide refrigeration cycle to assist in pre-cooling, but also employs a solar energy absorption refrigeration system to enhance energy efficiency. The proposed process is simulated and optimized using HYSYS and the particle swarm optimization algorithm, and energy, exergy, and economic analyses are performed. The energy analysis shows that the specific energy consumption of the proposed process is 5.2201 kWh/kg, a reduction of 10.67% compared to the base case. The exergy loss and exergy efficiency are 64,904 kW and 62.21%, which are 13.63% and 6.63% lower than the base case, respectively. The economic analysis shows that the total annualized cost of the process is USD 28.6 million per year. The proposed integrated liquefaction process not only realizes the high efficiency of energy utilization but also follows the development trend of integrated energy systems.

The effect of Mo content of 1400 MPa-grade high-strength bolt steel on hydrogen diffusion behavior and the hydrogen evolution reaction were studied using a hydrogen permeation experiment, potentiodynamic polarization tests, thermal desorption spectroscopy, and the first-principle calculation. Two 1400 MPa-grade high-strength bolt steels with different Mo content were used. Based on the potentiodynamic polarization tests, both steels’ electrochemical behavior was similar in the test range. The hydrogen permeation experiment showed that the process of hydrogen adsorption and absorption was significantly promoted, and hydrogen desorption and recombination were slightly promoted, with the Mo content increasing from 0.70 to 1.09 wt%. The thermal desorption spectroscopy showed the overall reaction of hydrogen permeation and evolution. The increasing Mo content facilitated hydrogen entry behavior and increased the hydrogen content. According to the first-principle calculation and the density functional theory, this phenomenon is induced by the stronger bonding ability of Mo-H than Fe-H. This work could guide the design of 1400 MPa-grade high-strength bolt steel.

A new catalyst, copper oxide/graphene oxide–diatomaceous earth (CuO/GO-DE), was prepared by the ultrasonic impregnation method. The optimal conditions for catalyst preparation were explored, and its structure and morphology were characterized by BET, XRD, SEM, TEM, FTIR, Raman and XPS. By taking ciprofloxacin as the target pollutant, the performance and reusability of CuO/GO-DE to degrade antibiotic wastewater was evaluated, and the optimal operating conditions were obtained. The main oxidizing substances in the catalytic system under different pH conditions were analyzed, as well as the synergistic catalytic oxidation mechanism. The intermediate products of ciprofloxacin degradation were identified by LC-MS, and the possible degradation process of ciprofloxacin was proposed.

In interstitial-free (IF) steel with a certain microtexture, the micro-orientation of grains is essential to understand the occurrence of hydrogen-induced cracking in body-centered cubic (BCC) structural steels. In this study, the hydrogen embrittlement (HE) susceptibility of IF steels was determined by slow strain rate tensile (SSRT) tests and hydrogen microprinting (HMT) experiments from the perspective of crystal orientation. The strength of the specimen with hydrogen was slightly higher than that without hydrogen, while the ductility and toughness were drastically reduced by hydrogen charging during the SSRT test. The HE susceptibility was characterized by the loss of elongation (Iδ) and toughness (Iψ), with losses of 46.3% and 70%, respectively. The microstructural observations indicate that cracks initiated along grains oriented in the {100} || normal direction (ND), and grain boundaries (GBs) around {100}||ND were prone to be enriched in hydrogen atoms; that is, {100} || ND showed poor resistance to intergranular cracking and susceptible to hydrogen segregation. HMT was used to confirm the above viewpoints. Meanwhile, the statistical results showed those high-angle misorientations of 50–60° deviation are the locations most vulnerable to fracture.

The resistance of the Al0.5Cr0.9FeNi2.5V0.2 high-entropy alloy (HEA) to hydrogen embrittlement (HE) was investigated by a slow strain rate test (SSRT), and the fracture surface was examined through a scanning electron microscope. Compared with other high-strength steels, Al0.5Cr0.9FeNi2.5V0.2 showed insignificant strength loss after hydrogen charging. The fracture surface of the hydrogen-charged specimens mainly consisted of dimples, and no intergranular morphology was observed. The coupling effect of the dispersed nano-structured precipitates and high-density dislocations in Al0.5Cr0.9FeNi2.5V0.2 improves the resistance to hydrogen-induced strength loss.

ObjectiveAlthough progress has been made in tuberculosis (TB) treatment, China still remains one of the high-burden TB countries. One important reason that has not received sufficient scholarly attention is that Chinese individuals tend to underestimate the threat of TB. This contributed to the high rate of delay in seeking TB treatment and noncompliance with doctors' regimen. Hence, this research examined how TB knowledge affected Chinese parents' risk perceptions and their efficacy appraisal in TB treatment, and how their risk perception and efficacy appraisal affected their intentions to seek timely TB treatment for their children and adhere to doctors' regimen.MethodsWe conducted an online cross-sectional survey with 1129 parents of children attending kindergarten, primary school, and middle school in Shajing, a region with high TB incidence in China. Perceived severity of TB threat to self and to others, perceived susceptibility, response efficacy, and self-efficacy were measured, in addition to TB knowledge and intentions to seek timely TB treatment and adhere to doctors' regimens.ResultsOrdinal least squares regression demonstrated that TB knowledge was positively associated with perceived severity of TB threat to self, perceived severity of TB threat to others, perceived susceptibility, response efficacy, and self-efficacy, but it did not affect their medical decisions. In addition, binary logistic regression revealed that response efficacy and self-efficacy predicted both intentions positively, and perceived severity of TB threat to self only enhanced Chinese individuals' intention to follow doctors' regimens.ConclusionHealth education aimed at knowledge improvement may be effective in changing one's perceptions of the given health threat but may not be effective to change their behavior. Thus, practitioners need to focus on changing Chinese parents' perceptions of TB rather than simply improving their knowledge. Specifically, it is necessary to lower their efficacy in self-management and enhance their perceived infectiousness of TB.

The grain size in TWIP steel had a double fractal distribution, with a uniform diameter threshold of approximately 36 μm. Based on this threshold value, the grains were divided into fine and coarse grain sets. A good linear relationship was found between the fractal dimension of the fine grain set (Dg1) and the fraction of Σ3 gain boundaries (GBs) (FΣ3). The distribution characteristics of the three types of GBs satisfy multifractal and generalized fractal characteristics. Importantly, the fractal structural parameters of the Σ3 GBs control the distribution characteristics and complexity of the total grain boundary network (GBN). Combined corrosion test, a quantitative relationship between the corrosion thickness loss and the Σ3 GBs fractal parameter as well as corrosion time was established. In the end, the optimal microstructure characteristics for improving the intergranular corrosion resistance of TWIP steel are discussed from the GB perspective. GB design based on fractal theory provides a promising solution to optimize material corrosion properties through analyzing complex GBN. Keywords: grain boundary engineering, Fractal theory, Grain distribution, Intergranular corrosion, TWIP steels

In pressurized water reactors, the existence of lead contamination can promote the corrosion of Alloy 690TT. During the manufacturing, transportation, and assembly processes, Alloy 690TT surface is easily scratched and it is easily ignored. The effect of added lead on the scratched surface is different from that on the unscratched surface. In the present study, Alloy 690TT was treated with mechanical polishing (MP) and electrochemical polishing (EP) to generate scratched and unscratched surfaces. With the addition of lead, the thickness of passive film on the MP sample increases by eight times, while that on the EP sample only slightly increases. These chemical composition changes of passive films induced by lead result in the drop of their electrical resistivity, and the electrical resistivity of passive film on the MP sample is reduced by two orders of magnitude, while that on the EP sample decreases only three times. Nevertheless, the thickness and electrical resistivity of passive film on the MP sample are always greater than those of the EP sample. The toxic effect of lead on the MP sample is more severe than that of the EP sample, which may be closely related to their subsurface microstructure. Therefore, Alloy 690TT should better avoid being scratched in the secondary circuit system of pressurized water reactors, as scratched behavior will result in a faster corrosion rate of Alloy 690TT with the presence of lead.

The new magnetostrictive material Fe-Ga alloy has drawn considerable attention due to its excellent performance. The microstructure of the Fe-Ga alloy, which varies with the state of preparation or processing, not only affects the magnetostriction but also the mechanical service stability, i.e., the stress corrosion cracking (SCC) property. In this paper, we report a comparison of the SCC behaviors for two states of Fe85Ga15 alloys by using constant load experiments and the electrochemical method. Results showed that the hot-rolled Fe85Ga15 alloy exhibited better mechanical properties compared to the as-cast Fe85Ga15 alloy. SCC was found in both Fe85Ga15 alloys in a 3.5 wt % NaCl solution, and the as-cast alloy was more sensitive to SCC. The normalized thresholds of SCC for the as-cast and hot-rolled Fe85Ga15 alloys are 0.34 and 0.81, respectively. Furthermore, results also indicated that the SCC mechanism is an anodic dissolution for the Fe85Ga15 alloy.

Hot-stamped steel has been widely used in automobile bumper and other safety components due to its high strength. Therefore, this paper investigates the effect of hydrogen content and strain rate on hydrogen-induced delay cracking (HIDC) behavior. The results showed that the plasticity of the steel significantly decreased with an increase in hydrogen content or a decrease in the strain rate. Fractography was analyzed after tensile tests. It was found that all of the pre-charged specimens cracked at large-sized inclusions when stretched at a strain rate of 1 × 10−3 s−1, which indicates that, in this case, the defect itself in the material had great influence on the extend properties. No inclusions were found at the main fracture origin area for hydrogen steady-state specimens, when stretched at a strain rate of 1 × 10−6 s−1, which demonstrated that a slower strain rate causes greater influence by hydrogen. However, for the non-pre-charged samples, the fractures surface showed that cracking originated from the defect near the sample surface, which was independent of strain rates.

When 2205 duplex stainless steel (DSS) is immersed in simulated seawater under high hydrostatic pressure, or in an electrochemically hydrogen charged state, a spindle-shaped product is found in the ferrite phase that seriously deteriorates the mechanical properties of 2205 DSS. This paper systematically studied the composition, structure, and properties of the hydrogen charging product. The results of a slow strain rate tensile test show that the hydrogen charging product evidently reduces the elongation of 2205 DSS, and microcracks mainly initiate at the interface between the hydrogen charging product and the ferrite matrix at either a low or a high strain rate. However, the elongation recovers to that of the hydrogen free sample after heating the sample at 300 °C for 0.5 h. The nano-hardness and reduced modules of the product are higher than those of the ferrite and austenite phases. An element analysis by energy dispersive spectroscopy (EDS) and secondary ion mass spectrometry (SIMS) indicates that the Ni and H contents in the hydrogen charging product are higher than in the normal ferrite area, and X-ray diffraction shows the characteristic peak of iron hydride at 40.07°. Moreover, a differential scanning calorimeter (DSC) test demonstrated that the phase decomposition temperature of the product is 268 °C, which coincides with the fact that it dissolves at a high temperature caused by the focused electron beam during transmission electron microscopy (TEM) analysis. All experimental results indicate that the hydrogen charging product is a hydride of FeH or (Fe, Ni)H.

A vacuum ultraviolet lamp based single photon ionization- (SPI-) photoelectron ionization (PEI) portable reflecting time-of-flight mass spectrometer (TOFMS) was designed for online monitoring gas samples. It has a dual mode ionization source: SPI for analyte with ionization energy (IE) below 10.6 eV and PEI for IE higher than 10.6 eV. Two kinds of sampling inlets, a capillary inlet and a membrane inlet, are utilized for high concentration and trace volatile organic compounds, respectively. A mass resolution of 1100 at m/z 64 has been obtained with a total size of 40 × 31 × 29 cm, the weight is 27 kg, and the power consumption is only 70 W. A mixture of benzene, toluene, and xylene (BTX), SO2, and discharging products of SF6 were used to test its performance, and the result showed that the limit of quantitation for BTX is as low as 5 ppbv (S/N = 10 : 1) with linear dynamic ranges greater than four orders of magnitude. The portable TOFMS was also evaluated by analyzing volatile organic compounds from wine and decomposition products of SF6 inside of a gas-insulated switchgear.

Hydrostatic pressure effects on pitting initiation and propagation in X70 steel are investigated by evaluating metastable pitting probability using electrochemical methods and immersion corrosion tests in containing chlorine ion solution. Potentiodynamic tests indicated that hydrostatic pressure can decrease the breakdown potential and lead to a reduced transpassivity region. Metastable test results revealed that hydrostatic pressure can increase metastable pitting formation frequency and promote stabilization of metastable pitting growth. Electrochemical impedance spectroscopy (EIS) results indicate that Hydrostatic pressure decreases the charge transfer resistance and increases the dissolution rate within the cavities. Corrosion test results also indicated that pitting initiation and propagation are accelerated by hydrostatic pressure. Result validity was verified by evaluating metastable pitting to predict pitting corrosion resistance.

Inclusion-induced pitting initiation mechanisms in X70 steel were investigated by scanning electron microscopy, scanning Kelvin probe force microscopy (SKPFM), immersion and electrochemical polarization tests in chloride-containing ion solutions. There are three inclusion types in the X70 steel. Corrosion test results indicated that pitting corrosion resistance of type A inclusion < type C inclusion < type B inclusion, i.e., (Mn, Ca)S < matrix < (Al, Ca)O. SKPFM test results show that the type A inclusion exhibited both lower and higher potentials than the matrix, while the type B inclusion exhibited higher potential than the matrix. The corrosion test and the SKPFM potential test results are consistent. Potentiodynamic polarization results indicate that the type A and C are active inclusions, while the type B is an inactive inclusion. Three kinds of possible mechanisms of inclusion-induced pitting corrosion are established for the X70 steel.

To counter thin and lightweight targets such as drone swarms, a specialized design of 7.62 mm energetic bullets has been developed. These bullets utilize reactive materials as the core encased in a copper jacket, offering the advantages of impact-induced energy release, multiple damage, and lightweight. The study involved the preparation of three energetic bullets using the reactive materials (different ratio of PTFE-Mg-Bi2O3 and PTFE-Mg-Bi2O3-W) and systematically evaluating their destructive effect. The results showed that three energetic bullets (EB-A, EB-B, and EB-W) successfully penetrated two-layer stacked 2 mm 50# cold-rolled steel targets, and the respective reaction durations observed during the penetration process were 4.1, 3.5, and 9.2 ms. After armor-piercing, energetic bullets released an amount of chemical energy and produced fragmentation, deflagration reactions, and overpressure destructive effects. To further investigate the damage mechanism of the three reactive material-filled bullets, a detailed analysis of PTFE-Mg-based reactive material, such as reaction energy, burning rate, combustion temperature field, reaction overpressure, was conducted. Our work provides a comprehensive understanding of energy release performance of the reactive materials and damage behavior of the energetic bullets.