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In this paper, numerical simulation is used to study the buffer layer material, thickness and structure on the reactive fragment load and its action time under blast impact loading conditions. The results show that the buffer layer can significantly reduce the peak pressure of the detonation wave acting on the reactive fragment and prolong the action time; the buffering capacity of different buffer materials is different; for the same material, the buffering capacity is proportional to the material thickness; compared with a single layer of buffer layer, the buffer layer with the same thickness and composite structure has a stronger capacity.

The influence of the fragment velocity gradient on the hit density under the dynamic missile-target meeting condition is discussed using theoretical analysis, and the analytical relationship is obtained. The results show that under static explosion conditions, the fragment hit density is independent of the velocity gradient of the fragment group. Under dynamic conditions, the distribution bandwidth of the fragments on the target becomes wider with the increase of the velocity of the missile-target meeting and the velocity gradient of the fragment group, and the increase of the fragment bandwidth decreases the fragment hit density.

For the air-to-air missile warhead, there is a cabin with a certain thickness at a distance around the fragments. At present, the influence of missile cabin has not yet been taken into account in the study of fragment velocity. In this paper, based on the law of conservation of energy, the theoretical equation of fragment velocity considering the kinetic energy of cabin debris was deduced. Then, the rationality of the theoretical formula is validated through the static explosion experiments of two prototype warheads, one with a titanium alloy cabin and the other without any cabin. It was found that after the warhead is equipped with the cabin, part of the energy is consumed to drive the cabin debris, resulting in a decrease in fragment velocity, but the velocity of cabin debris was greater than that of fragment of warheads without any cabin. Besides, through numerical simulation, the driving process of fragments and cabin debris during explosive detonation loading of the warhead with the cabin was studied, which can be divided into six stages, and the error between numerical result and experimental value is not more than 4.8%. Finally, the variety regulation of fragment velocity and cabin debris velocity at different interval distances was further studied by numerical simulation. The results indicate that fragment velocity of warheads with cabin at different interval distances is basically the same, but cabin debris velocity decreases with the increase of interval distance. This conclusion can provide a reference for the structural design and fragment velocity evaluation of warheads with cabin.

Background The development of vascular calcification (VC) in diabetes is closely related to the endothelial-to-mesenchymal transition (EndMT). We found that microRNA-32-5p (miR-32) was elevated in the plasma of calcification patients. However, it is unclear whether miR-32 mediates the function of bone marrow mesenchymal stem cell-derived extracellular vesicles (BMSC-EVs) in type 2 diabetes (T2D) VC. Methods BMSC-EVs were characterized by TEM, NTA, Western blotting, and confocal microscopy. Alizarin Red and ALP staining assessed the severity of VC. qRT-PCR and Western blotting evaluated the expression of BMP2, RUNX2, GPX4, SLC7A11, VE-cadherin, and N-cadherin, while immunofluorescence was used for detecting VE-cadherin and N-cadherin. In vivo validation was performed using miR-32 –/– and ApoE –/– mice. RNA sequencing (RNA-seq) and bioinformatics analysis was conducted to explore underlying mechanisms. Results We demonstrated that BMSC-EVs attenuate VC in endothelial cells (ECs) and inhibit EndMT. In vivo, histological analysis showed that treatment with BMSC-EVs significantly reduced the severity of VC associated with T2D. Notably, knockout of miR-32 further enhanced the inhibitory effect of BMSC-EVs on VC. Mechanistically, transcriptomic and functional analyses suggest that the protective effect of BMSC-EVs on VC is associated with regulation of the MAPK/FoxO signaling pathway, potentially mediated by modulation of ferroptosis. Conclusion These findings demonstrate that BMSC-EVs attenuate T2D-associated VC, partially through miR-32-mediated suppression of EC ferroptosis.

Vascular calcification (VC) in type 2 diabetes (T2D) poses a serious threat to the life and health of patients. However, its pathogenesis remains unclear, resulting in a lack of effective treatment for the root cause. It is found that both intestinal Bacteroides fragilis (BF) and peripheral M2 monocytes/macrophages are significantly elevated in patients with T2D VC. M2 macrophages are identified as a significant risk factor for T2D VC. Both BF and their extracellular vesicles (EV) promote T2D VC and facilitate macrophage M2 polarization. Macrophages clearance significantly antagonized BF EV‐induced T2D VC in mice. Mechanistically, EV‐rich double‐stranded DNA (dsDNA) activates stimulator of interferon response cGAMP interactor 1 (Sting), promotes myocyte enhancer factor 2D (Mef2d) phosphorylation, upregulates tribbles pseudokinase 1 (Trib1) expression, and induces macrophage M2 polarization. Concurrently, Mef2d activated by the EV targets and upregulates the expression of pro‐calcification factor Serpine1, thereby exacerbating T2D VC. Clinical studies have shown that Serpine1 is significantly elevated in the peripheral blood of patients with T2D VC and is closely associated with T2D VC. In summary, this study reveals that intestinal BF promotes Trib1 expression through the EV‐Sting‐Mef2d pathway to induce macrophage M2 polarization and upregulates serpin family E member 1 (Serpine1) expression, thereby aggravating T2D VC. The findings provide a new theoretical and experimental bases for optimizing the strategies for prevention and treatment of T2D VC. Bacteroides fragilis, an intestinal bacterium associated with T2D VC, secretes extracellular vesicles that activate the Sting‐Mef2d‐Trib1 signaling pathway, promoting macrophage M2 polarization. Additionally, Extracellular vesicles activates the Sting‐Mef2d axis, which enhances the expression and secretion of Serpine1, thereby facilitating VC. Notably, both M2 macrophages and Serpine1 levels in serum show a positive correlation with T2D VC.

To investigate the impact of the variation rate of the thickness of the conical liner on the damage performance of shaped charge jet during its formation process, using the numerical simulation software Autodyn to construct a numerical model for conducting simulation computations. Subsequently, the corresponding numerical simulation results were acquired, and parameters such as velocity, mass, and penetration depth in the numerical simulation outcomes of shaped charge jet formed from liners with different thickness variation rates were analyzed. The findings reveal that the velocity at the head of jet ascends as the variation rate of the liner wall thickness increases. Meanwhile, jet head diameter diminishes with the augmentation of the thickness variation rate, and the penetration depth expands in tandem with the growth of the thickness variation rate.

Negative motor evoked potentials after cerebral infarction, indicative of poor recovery of limb motor function, tend to be accompanied by changes in fractional anisotropy values and the cerebral pe-duncle area on the affected side, but the characteristics of these changes have not been reported. This study included 57 cases of cerebral infarction whose motor evoked potentials were tested in the 24 hours after the first inspection for diffusion tensor imaging, in which 29 cases were in the negative group and 28 cases in the positive group. Twenty-nine patients with negative motor evoked potentials were divided into two groups according to fractional anisotropy on the affected side of the cerebral peduncle： a fractional anisotropy 〈 0.36 group and a fractional anisotropy 〉 0.36 group. All patients underwent a regular magnetic resonance imaging and a diffusion tensor imaging examina- tion at 1 week, 1, 3, 6 and 12 months after cerebral infarction. The FugI-Meyer scores of their hemiplegic limbs were tested before the magnetic resonance and diffusion tensor imaging exami-nations. In the negative motor evoked potential group, fractional anisotropy in the affected cerebral peduncle declined progressively, which was most obvious in the first 1-3 months after the onset of cerebral infarction. The areas and area asymmetries of the cerebral peduncle on the affected side were significantly decreased at 6 and 12 months after onset. At 12 months after onset, the area asymmetries of the cerebral peduncle on the affected side were lower than the normal lower limit value of 0.83. FugI-Meyer scores in the fractional anisotropy ≥0.36 group were significantly higher than in the fractional anisotropy 〈 0.36 group at 3-12 months after onset. The fractional anisotropy of the cerebral peduncle in the positive motor evoked potential group decreased in the first 1 month after onset, and stayed unchanged from 3-12 months; there was no change in the area of the cerebral peduncle in the first 1-12 months after cerebral infarction. These findings confirmed that if the fractional anisotropy of the cerebral peduncle on the affected side is 〈 0.36 and the area asym-metries 〈 0.83 in patients with negative motor evoked potential after cerebral infarction, then poor hemiplegic limb motor function recovery may occur.

A new technology of manufacturing nanometer oxide powders through vacuum vapor combustion synthesis has been invented. Using this new technology a series of research works have been developed, for example, nanometer Bi^sub 2^O^sub 3^, ZnO, Sb^sub 2^O^sub 3^,and so on have been manufactured by vacuum vapor combustion synthesis, all the works have obtained good indexes, for example, the purity of Bi^sub 2^O^sub 3^ powder may be higher than 99.99%,the particle average diameter D^sub 50^ can be controlled between 50 and 100nm, the particle diameter can be distributed over a small area, the particle shape is regular, which is about to a spheroid. Using the new technology to manufacture Bi^sub 2^O^sub 3^ powder, not only the product has the characters of high-purity and ultra-fine, but also compared with the other processes of producing Bi^sub 2^O^sub 3^ powder, the vacuum vapor combustion synthesis technology has the characters of a short flow and a low cost, the research works have testified this is a new technology whose products have a wide application area and have a powerful market competition ability. [PUBLICATION ABSTRACT]

Because of their exotic electronic properties and abundant active sites, two-dimensional (2D) materials have potential in various fields. Pursuing a general synthesis methodology of 2D materials and advancing it from the laboratory to industry is of great importance. This type of method should be low cost, rapid and highly efficient. Here, we report the high-yield synthesis of 2D metal oxides and hydroxides via a molten salts method. We obtained a high-yield of 2D ion-intercalated metal oxides and hydroxides, such as cation-intercalated manganese oxides (Na 0.55 Mn 2 O 4 ·1.5H 2 O and K 0.27 MnO 2 ·0.54H 2 O), cation-intercalated tungsten oxides (Li 2 WO 4 and Na 2 W 4 O 13 ), and anion-intercalated metal hydroxides (Zn 5 (OH) 8 (NO 3 ) 2 ·2H 2 O and Cu 2 (OH) 3 NO 3 ), with a large lateral size and nanometre thickness in a short time. Using 2D Na 2 W 4 O 13 as an electrode, a high performance electrochemical supercapacitor is achieved. We anticipate that our method will enable new path to the high-yield synthesis of 2D materials for applications in energy-related fields and beyond. 2D materials with exotic electronic properties are increasingly important for the development of low-dimensional electronic devices. Here, Hu et al . have developed a fast and efficient method to synthesize 2D metal oxides and hydroxides, further enabling 2D electronics.

Understanding the mechanisms, intensity, and spatio-temporal heterogeneity of the impacts of urbanization and eco-environmental quality on carbon storage is crucial for achieving carbon neutrality goals. This study constructed a multiscale spatio-temporal analysis framework using multi-source remote sensing data, the InVEST model, and the multiscale geographically weighted regression (MGWR) model. Then, the effects of multiple factors on regional carbon storage were assessed in an empirical study involving 199 counties in Beijing-Tianjin-Hebei. The results showed that the carbon storage loss in the Beijing-Tianjin-Hebei region from 2010 to 2018 was 58.87 Tg C, with an annual relative loss rate of 0.16%. The MGWR model used in this study explained more than 98% of the spatial variation in regional carbon storage. In contrast, the impacts of various urbanization and eco-environmental indicators on regional carbon storage varied with the spatial and temporal variation. Overall, urban land structure and vegetation growth strongly influenced regional carbon storage resulting from urbanization and eco-environmental quality, respectively. In addition, based on an analysis of spatial context, MGWR suggests that the northwestern mountains in the Beijing-Tianjin-Hebei region have a greater potential to store more carbon than the other regions. This study also details the impact of future sustainable land use on regional carbon storage. Our findings can provide a scientific reference for formulating relevant carbon storage conservation policies.