This research involved studying the characteristics of composite electromagnetic scattering from a rocket moving above actual terrain using the finite-difference time-domain method. The angular ...distribution curve of the composite scattering coefficient was obtained, and the influences of factors such as the angle of incidence, the frequency of the incident electromagnetic wave, the content of moisture in soil, the dielectric constant of the rocket-shell material, the height of the rocket, and the undulation of the terrain on the composite scattering coefficient were investigated. Results show that the composite scattering coefficient oscillates with the scattering angle and increases in the direction of mirror reflection. It also decreases with increasing angle of incidence, frequency of the incident wave, and altitude of the rocket, while it increases with increasing soil moisture and dielectric constant of the rocket-shell materials. Although the influence of different terrain undulations on the composite scattering coefficient is noticeable, it follows no fixed pattern.
•The dimension accuracy of quartz pendulous reed is as high as ± 3 μm and the chipping is only 4 μm.•The maximum stress is 35.3 KPa, which is much smaller than the stress generated by CO2 laser ...ablation cutting (24.1 MPa).•The mechanical damage caused by the local thermal effect is the main form of picosecond laser modification.
The Quartz pendulous reed is the core part of the quartz flexible accelerometer. The current quartz pendulous reed forming technology has shortcomings, such as poor processing quality and high production cost. In this paper, picosecond laser modification assisted wet etching technology is proposed to prepare quartz pendulous reed. The modification mechanism of fused silica induced by picosecond laser was investigated. Different from the network structure changes caused by femtosecond laser, mechanical damage is the main form of picosecond laser modification. The mapping among etching time, etching temperature and HF solution concentration were studied by using the control variable method. The proposed picosecond laser assisted wet etching technology has the advantages of high dimensional accuracy, good edge quality, low residual stress, and high efficiency.
Antigenic stimulation promotes T cell metabolic reprogramming to meet increased biosynthetic, bioenergetic, and signaling demands. We show that the one-carbon (1C) metabolism enzyme ...methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) regulates de novo purine synthesis and signaling in activated T cells to promote proliferation and inflammatory cytokine production. In pathogenic T helper-17 (Th17) cells, MTHFD2 prevented aberrant upregulation of the transcription factor FoxP3 along with inappropriate gain of suppressive capacity. MTHFD2 deficiency also promoted regulatory T (Treg) cell differentiation. Mechanistically, MTHFD2 inhibition led to depletion of purine pools, accumulation of purine biosynthetic intermediates, and decreased nutrient sensor mTORC1 signaling. MTHFD2 was also critical to regulate DNA and histone methylation in Th17 cells. Importantly, MTHFD2 deficiency reduced disease severity in multiple in vivo inflammatory disease models. MTHFD2 is thus a metabolic checkpoint to integrate purine metabolism with pathogenic effector cell signaling and is a potential therapeutic target within 1C metabolism pathways.
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•MTHFD2 is critical for activated CD4 T cells to maintain de novo purine synthesis•Insufficient MTHFD2 promotes Treg cell-like phenotypes and metabolism in Th17 cells•Inhibition of MTHFD2 suppresses mTORC1 signaling and alters histone methylation•MTHFD2 can be targeted to protect against inflammation and autoimmunity in vivo
Nucleotide synthesis is required to support rapid T cell proliferation. Sugiura et al. show that de novo purine metabolism signals direct T cell differentiation and function and identify MTHFD2 as a metabolic checkpoint and therapeutic target for inflammatory diseases.
To reduce the wear of 20Cr2Ni4A alloy steel, a new method to implant diamond nanoparticles onto the surface by employing laser shock peening was presented. Studies demonstrated that with implanted ...diamond nanoparticles, the crater depth induced by laser shock peening was reduced by 23.7 μm. A lower surface roughness of 2.25 μm was obtained, which is 44.6% of the sample treated by laser shock peening only. The nano-hardness was as high as 4.93 GPa, which is 31% higher than the original samples. The coefficient of friction of 20Cr2Ni4A steel was reduced to 0.31 and the wear loss was reduced to 4 mg, which is only 50% of that of the original samples. The wear mechanism of the samples with implanted diamond nanoparticles was analyzed and provided new concepts and methods for solving the problem of wear failure.
•The diamond nanoparticles were successfully implanted onto the surface of 20Cr2Ni4A alloy steel via LSWNI treatment.•Lower surface roughness of 2.25 μm was obtained via LSWNI, which is 44.6 % of samples treated by conventional LSP only.•After LSWNI treatment, the nano-hardness and elastic modulus could be as high as 4.93 GPa and 208.63 GPa, respectively.•The wear loss is reduced 50 % after treatment of LSWNI compared to untreated samples.
Zinc is an important micronutrient for the growth and development of human body and plants. Proper use of nitrogen fertilizer and foliar application of Zn have been proven to be important agronomic ...measures to improve zinc accumulation and biofortification in rice grains. However, little is known about the physiological mechanism of remobilization of Zn and characteristics of its subcellular distribution in source organs in response to N/Zn supply. In this study, the distribution of Zn at subcellular level in rice stem-sheaths, leaves, and glumes and their apparent contribution rates were examined; and the accumulation mechanism of Zn in rice grains was further explored. Zn concentration and accumulation, especially the contribution rate of stem-sheaths (43.47%) were higher than that of leaves (12.46%) and glumes (11.13%), indicating the stem-sheaths may be the main organs of Zn storage in rice. The proportions of Zn in soluble fraction in three vegetative organs were increased under N topdressing and N/Zn combined treatment and thus enhances the ability of Zn transportation from these organs to grains. In addition, Zn concentration of brown and milled rice could be increased by applying Zn fertilizer on panicles (ZnS, N + ZnS), which suggests the possibility of applying agronomic measures to enhance Zn translocation from vegetative organs to grains, thus to improve the accumulation of Zn in rice grain.
The morphological and histological traits of the gastrointestinal tract (GIT) enable the animal to perform some specific functions that enhance the species’ adaptability to environments. The plateau ...zokor (Eospalax baileyi) is a subterranean rodent that mainly forages on plant roots in the Qinghai-Tibet Plateau, but little is known about the mechanism by which the plateau zokor digests roots that have high fiber contents. In this study, we used comparative anatomy methods to compare the morphological and histological traits of the GIT of both the plateau zokor and the plateau pika (Ochotona curzoniae), a small, fossorial lagomorph that forages aboveground plant parts, in order to clarify the traits of the plateau zokor’s GIT and to understand its adaptations to high-fiber foods. The results showed that the foods which plateau zokors eat have a higher fiber content than those which the plateau pikas eat. The plateau zokor has a double-chambered and hemi-glandular stomach (the tubular glands are only in the gastric corpus II, and the gastric fundus is keratinized), whereas the plateau pika has a simple, wholly glandular stomach. The gross morphological indicators (organ index and relative length) of the GIT were significantly lower in the plateau zokor than they were in the plateau pika (p < 0.001). However, the thickness of the gastric corpus II mucosal layer and the gastric fundus muscle layer are significantly higher in the plateau zokor than they are in the plateau pika (p < 0.001), and the thickness of each layer of intestinal tissue is higher in the plateau zokor than it is in the plateau pika. Additionally, the small intestinal villi also are higher and wider in the plateau zokor than they are in the plateau pika. Our results suggest that instead of adapting to digest the high-fiber diet by expanding the size of the GIT, the plateau zokor has evolved a complex stomach and a well-developed gastrointestinal histological structure, and that these specialized GIT structures are consistent with an optimal energy-economy evolutionary adaptation strategy.
YAP and TAZ (YAP/TAZ), two major effectors of the Hippo signaling pathway, are frequently activated in human cancers. The activity of YAP/TAZ is strictly repressed upon phosphorylation by LATS1/2 ...tumor suppressors. However, it is unclear how LATS1/2 are precisely regulated by upstream factors such as Hippo kinases MST1/2. Here, we show that WWC proteins (WWC1/2/3) directly interact with LATS1/2 and SAV1, and SAV1, in turn, brings in MST1/2 to phosphorylate and activate LATS1/2. Hence, WWC1/2/3 play an organizer role in a signaling module that mediates LATS1/2 activation by MST1/2. Moreover, we have defined a minimum protein interaction interface on WWC1/2/3 that is sufficient to activate LATS1/2 in a robust and specific manner. The corresponding minigene, dubbed as SuperHippo, can effectively suppress tumorigenesis in multiple tumor models. Our study has uncovered a molecular mechanism underlying LATS1/2 regulation and provides a strategy for treating diverse malignancies related to Hippo pathway dysregulation.
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•WWC1/2/3 mediate LATS1/2 activation by MST1/2 in a SAV1-dependent manner•WWC1/2/3 organize an MST1/2-SAV1-WWC1/2/3-LATS1/2 signaling module•SuperHippo minigene mimicking WWC1/2/3 robustly and specifically activates LATS1/2•SuperHippo effectively suppresses tumorigenesis driven by YAP/TAZ activation
In this article, Qi et al. uncover a role of WWC family proteins in transducing signals from Hippo kinases to LATS1/2. Based on this mechanism, a SuperHippo minigene has been engineered to robustly and specifically activate LATS1/2, which, in turn, inhibit YAP/TAZ oncoproteins and tumorigenesis in multiple models.
In this paper, the ablation of fused silica by femtosecond laser burst mode and normal pulse mode was studied by three-dimensional two-temperature model and verified by experiments. The change of ...electron heat capacity, electron conductivity, reflectivity, and transmissivity of fused silica irradiated by femtosecond laser pulses were studied. The ablation crater shape was predicted and compared with experiments. The incubation effect induced by sub-pulses in a burst was investigated. It was found that when the sub-pulse separation time is 50 ns, the incubation effect of burst mode decreases with the increase of the number of sub-pulses, which is caused by the heat diffusion during time between sub-pulses. However, the incubation effect of burst mode increases with increase of sub-pulse number when the sub-pulse separation time is 1 ps. An optimal combination of sub-pulse number and sub-pulse separation time was found, in which the highest machining efficiency and the smallest thermal damage area could be obtained.
•A 3D TTM including absorption characteristic is proposed to study the process of femtosecond laser ablation of fused silica.
Aggression is an instinctive behavior that has been reported to be influenced by early-life stress. However, the potential effects of acute stress during the postweaning period, a key stage for brain ...development, on defensive aggression and the associated mechanism remain poorly understood. In the present study, aggressive behaviors were evaluated in adolescent mice exposed to postweaning stress. Serum corticosterone and testosterone levels, neural dendritic spine density, and gut microbiota composition were determined to identify the underlying mechanism. Behavioral analysis showed that postweaning stress reduced locomotor activity in mice and decreased defensive aggression in male mice. ELISA results showed that postweaning stress reduced serum testosterone levels in female mice. Golgi staining analysis demonstrated that postweaning stress decreased neural dendritic spine density in the medial prefrontal cortex of male mice. 16S rRNA sequencing results indicated that postweaning stress altered the composition of the gut microbiota in male mice. Combined, these results suggested that postweaning stress alters defensive aggression in male mice, which may be due to changes in neuronal structure as well as gut microbiota composition. Our findings highlight the long-lasting and sex-dependent effects of early-life experience on behaviors.
•Postweaning stress reduced defensive aggression in male mice.•Postweaning stress induced synaptic remodeling in the mPFC in male mice.•Postweaning stress changed the gut microbial composition in male mice.
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