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Introduction: Major depressive disorder (MDD) affects about 17% population in the world. Although abnormal energy metabolism plays an important role in the pathophysiology of MDD, however, how deficiency of adenosine triphosphate (ATP) products affects emotional circuit and what regulates ATP synthesis are still need to be elaborated. Aims: Our study aimed to investigate how deficiency of PGAM5‐mediated depressive behavior. Results: We firstly discovered that PGAM5 knockout (PGAM5−/−) mice generated depressive‐like behaviors. The phenotype was reinforced by the observation that chronic unexpected mild stress (CUMS)‐induced depressive mice exhibited lowered expression of PGAM5 in prefrontal cortex (PFC), hippocampus (HIP), and striatum. Next, we found, with the using of functional magnetic resonance imaging (fMRI), that the functional connectivity between PFC reward system and the PFC volume were reduced in PGAM5−/− mice. PGAM5 ablation resulted in the loss of dendritic spines and lowered density of PSD95 in PFC, but not in HIP. Finally, we found that PGAM5 ablation led to lowered ATP concentration in PFC, but not in HIP. Coimmunoprecipitation study showed that PGAM5 directly interacted with the ATP F1F0 synthase without influencing the interaction between ATP F1F0 synthase and Bcl‐xl. We then conducted ATP administration to PGAM5−/− mice and found that ATP could rescue the behavioral and neuronal phenotypes of PGAM5−/− mice. Conclusions: Our findings provide convincing evidence that PGAM5 ablation generates depressive‐like behaviors via restricting neuronal ATP production so as to impair the number of neuronal spines in PFC. [ABSTRACT FROM AUTHOR]

Understanding the plastic behavior of crack tips is crucial for improving the fracture toughness of nanometals. Although many studies are carried out, most previous studies focus on pure metals, and how the crack tip accommodates the plastic deformation of highly concentrated solid‐solution alloys is unclear owing to a lack of direct atomic‐scale evidence. In this study, the atomic‐scale plastic behavior of the crack tip in face‐centered cubic (FCC) AuCu alloy nanocrystals is observed in situ, which provides direct evidence that plastic deformation is governed by the generation of deformation twins and hexagonal close‐packed (HCP) 2H and 4H phases, recurrence of reversible FCC‐HCP phase transitions, and detwinning, which are rarely observed in pure metals. This unusual behavior originates from the inherent chemical inhomogeneity of the AuCu alloy, which inhibits twin thickening via partial dislocations on the adjacent plane, instead of random generation of deformation twins, phase transitions, and reversible processes. This naturally implies a similar behavior at the crack tip in other highly concentrated solid‐solution alloys, including high‐medium‐entropy alloys, providing important insights that greatly improve the understanding of the fracture toughness of metallic materials. [ABSTRACT FROM AUTHOR]

AbstractThe emergence of new energetic materials has significantly intensified the thermal damage effects at explosion sites, The traditional damage assessment methods face severe challenges. Static models used for thermal dose calculations rely on equivalence, failing to capture the dynamic characteristics of an explosive fireball. Furthermore, existing dynamic fireball models only characterize time as a variable, neglecting the energy characteristics. In this study, we obtain fireball diameter and central height data through thermal imaging which serve as essential inputs for our model construction. By integrating the geometric and physical characteristics of the explosion fireball, we develop a two-variable function model (time and equivalent) to predict changes in the fireball during its primary damage phase. The effective thermal region of the fireball is treated as a Lambertian body to derive an equivalent temperature. Using this model and equivalent temperature, the heat dose and corresponding damage effects of the fireball are calculated at five locations for four distinct equivalent masses using the Stefan-Boltzmann law. By applying the calculated thermal dose data to the pressure effect model in a static explosion field according to the explosion similarity law, we construct an equivalent damage model with an average error of 4.09%. This model, valid within a 1.17–4.76 m/kg1/3 range, reliably assesses thermal damage for high-energy materials. This method provides a better basis for the assessment of thermal damage caused by various types of explosions. [ABSTRACT FROM AUTHOR]

To investigate the effect of enhanced fermentation with different species of Aspergillus on the flavor of Douchi, the quality differences between enhanced fermentation by A. flavus 7214, A. flavus 7622 or A. oryzae and natural fermentation were compared. The results showed that enhanced fermentation with A. flavus promoted an increase in the total amount of free amino acids and organic acids, particularly glutamic and acetic acids, in Douchi. A total of nine classes of compounds including esters (20), acids (11), aldehydes (12), ketones (9), alcohols (7), pyrazines (8), alkanes (10), phenols (7) and other compounds (8) were identified by gas chromatography-mass spectrometry (GC-MS). While higher levels of pyrazine and phenolic compounds were observed in naturally fermented Douchi, enhanced fermented Douchi had more acids and aldehydes. In addition, some new volatile components, such as methyl phenyl acetate and ethyl linoleate, were formed by enhanced fermentation. Electronic nose analysis revealed that the flavor of A. flavus 7622 fermented Douchi was closest to that of naturally fermented Douchi, while the largest flavor differences were found between A. flavus 7214 fermented and naturally fermented Douchi. Furthermore, A. flavus 7214-fermented Douchi had better overall flavor in sensory evaluation, mainly in terms of aroma, sourness, sweetness, and umami. To summarize, enhanced fermentation promoted the release of free amino acids, organic acids, and volatile compounds, thereby having a significant impact on sweetness, umami, and aroma. These results could provide theoretical guidance for the industrial production of Liuyang Douchi.

The emergence of drug-resistant bacteria and the lack of effective antimicrobial agents have posed a threat to public safety, so a new efficient strategy is needed to deal with the increasing severity of bacteria. Herein, a substitute antibacterial agent with high stability and biocompatibility was synthesized by incorporating lysine hydrochloride and copper sulfate pentahydrate following the liquid-phase synthesis method. The composition and structure of the Cu(ii) complex (Lys–Cu) were characterized by performing ultraviolet-visible spectrophotometry, Fourier-transform infrared spectroscopy, X-ray diffractometry (XRD), thermogravimetric analysis-differential scanning calorimetry, and single-crystal XRD. The crystal structure of Lys–Cu belongs to a monoclinic system, space group P21, with cell parameters of a = 5.14350(10), b = 16.8308(2), c = 11.4915(2) Å, Z = 2, and D = 1.548 g·cm−3. Bacteriostatic tests were carried out on Escherichia coli and Staphylococcus aureus. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of Lys–Cu against S. aureus were 0.3125 and 0.9250 mg·mL−1, respectively. The MIC and MBC values of Lys–Cu against bacterial strain E. coli were 0.4685 and 0.9250 mg·mL−1, respectively.

Al–Li alloy has been widely used in the aerospace field owing to its high strength and low density. In this study, alternating current cold metal transfer (AC CMT) along with a high-frequency pulse current technique was used to weld a 2060 Al–Li alloy using an ER5356 wire. The effect of pulse frequency on the arc shape, microstructure, and mechanical properties of the welded joints was examined, and mechanical performance testing was conducted. The results revealed that the arc diameter, arc length, and arc volume showed a trend of increasing first and then decreasing with an increase in the pulse frequency and reached their peak values when the pulse frequency was 50 kHz. Coupling the welding process with a high-frequency pulse resulted in grain refinement, which was attributed to the stirring action of the arc force. Both the porosity levels and grain size decreased with increasing frequency. When the pulse frequency was 70 kHz, the porosity level was the lowest, and the grain size was refined to 24.1 μm. The tensile strength of the welded joints also increased with the pulse frequency, and a maximum tensile strength of 249 MPa was observed at 70 kHz.