Progesterone Activates the Histone Lactylation-Hif1α-glycolysis Feedback Loop to Promote Decidualization.

Decidualization is a progesterone-dependent cellular differentiation process that is essential for establishing pregnancy. Robust activation of glycolysis and lactate synthesis during decidualization is remarkable, but their developmental functions remain largely unknown. Herein, we identify that endometrial lactate production plays a critical role in establishing local histone lactylation, a newly identified histone modification, and is important for ensuring normal decidualization. Enhanced endometrial glycolysis is the hallmark metabolic change and is tightly coupled with H4K12la during decidualization. Inhibition of histone lactylation impaired decidualization, in either physiological conception or in vivo and in vitro induced decidualization models. Mechanistic study based on CUT&Tag and ATAC-seq revealed that a transcriptional factor hypoxia-inducible factor 1 α (Hif1α) is the critical regulatory target of H4K12la, and in turn forms an H4K12la-Hif1α-glycolysis feedback loop to drive decidualization. Moreover, we demonstrate that the loop is directly activated by progesterone during decidualization. Our study not only advances the current knowledge of the role of lactate in regulating uterine function, but also establishes a novel functional link among the major endocrine factors, endometrial metabolic change, and epigenetic modification during endometrial remodeling. These findings present valuable clues to develop clinical intervention strategies to improve pregnancy outcomes following both natural conception and assisted reproduction.

Achieving remarkable energy storage enhancement in polymer dielectrics via constructing an ultrathin Coulomb blockade layer of gold nanoparticles.

High-energy density polymer dielectrics play a crucial role in various pulsed energy storage and conversion systems. So far, many strategies have been demonstrated to be able to effectively improve the energy density of polymer dielectrics, but sophisticated fabrication processes are usually needed which result in high cost and poor repeatability. Herein, an easy-operated sputtering and hot-pressing process is developed to significantly enhance the energy density of polymer dielectrics. Surprisingly, for the poly(vinylidene fluoride-hexafluoropropylene) films sputtered with merely 0.0064 vol% gold nanoparticles, the energy density is remarkably improved by 84.3% because of the concurrent enhancements in breakdown strength (by 37.5%) and dielectric permittivity (by 25.5%), which is demonstrated to have originated from the unique Coulomb blockade and micro-capacitor effect of the gold nanoparticles. It is further confirmed that this design strategy is also applicable for commercial biaxially oriented polypropylene and poly(methyl methacrylate). This work offers a novel, easy-operated and universally applicable route to improve the energy density of polymeric dielectrics, which paves the way for their application in modern electronics and power modules.

Two-photon photodynamic therapy based on FRET using tumor-cell targeted riboflavin conjugated graphene quantum dot.

The photodynamic therapy (PDT) is considered as a noninvasive and photo-controlled treatment for various cancers. However, its potential is not fully developed as current clinically approved photosensitizers (PSs) mainly absorb the light in the UV-visible region (less than 700 nm), where the depth of penetration is inadequate for reaching tumor cells under deeper tissue layers. Furthermore, the lack of specific accumulation capability of the conventional PSs in the tumor cells may cause serious toxicity and low treatment efficiency. To address these problems, riboflavin (Rf) conjugated and amine-functionalized nitrogen-doped graphene quantum dots (am-N-GQD) are herein proposed. Rf functions as both photosensitizer and targeting ligand by indirect excitation through intra-particle fluorescence resonance energy transfer (FRET) via two-photon (TP) excited am-N-GQD, to enhance the treatment depth, and further am-N-GQD-Rf accumulation in cancer cells using Rf transporter family (RFVTs) and Rf carrier proteins (RCPs). The one-photon (OP) and two-photon(TP)-PDT effect and cellular internalization ability of the am-N-GQD-Rf were investigated in vitro in different cancel cell lines. Besides the excellent cellular uptake as well TP-PDT capability, the superior biocompatibility of am-N-GQD-Rf in vitro makes it promising candidate in PDT.

Numerical study on the wall-impinging diesel spray soot generation and oxidation in the cylinder under cold-start conditions of a diesel engine.

The combustion of wall-impinging diesel spray of heavy-duty diesel engines deteriorates combustion quality under cold-start conditions, making it difficult to control soot emissions. To investigate the causes of soot increase in the combustion of wall-impinging spray at low temperature and low speed starting conditions, the effect of the starting fuel mass on the soot formation and oxidation process was analyzed using a multidimensional computational fluid dynamics (CFD) model. The results show that the diesel spray is guided by the piston wall and the limited space, the spray impinged on the wall and the vapor-phase fuel flowed in the spray interaction zone. Thus, the soot mainly accumulates in the spray interaction zone, the region near the cylinder head and the bowl wall in the combustion chamber bowl. The soot from the vapor of deposited fuel film in the piston bowl wall and near wall region accumulates continuously in the after combustion stage, becoming the main source of soot emissions at the time of exhaust valve opening (EVO). Increasing the mass of starting fuel raises the mass of the rich mixture and wall-impinging fuel, which enhances the mismatch between fuel and air, resulting in higher soot generation, while soot is more difficult to be completely oxidized by OH radicals, and ultimately soot emissions increase significantly. It can be deduced that the engine-optimized injection strategy may mitigate the increase in soot emissions at high start-up fuel injection conditions.

Effect of wall parameters on impinging combustion and soot emission characteristics of heavy-duty diesel engine at low temperature.

The effect of wall parameters on combustion and soot emission characteristics remains to be revealed so far, especially in the case of spray impingement at low temperatures. Therefore, the visualization experiments are carried out in a constant volume combustion chamber using the Mie scattering and direct photography techniques, and the two-color method was used to extract the flame temperature and soot volume. The results show that increased wall distance and wall angle contribute to fast and stable ignition, but result in more soot production. In addition, the lower the ambient temperature, the more prominent the above characteristics are. At Tamb = 820 K, as the wall distance increases from 40 mm to 60 mm, the liquid spray impingement changes to the vapor impingement, so the ignition delay shortens, and the flame area and natural luminance increase significantly. At lower Tamb = 770 K, a complete misfire is observed at Lw = 40 mm but the ignition remains stable at Lw = 60 mm. The variation of the ignition characteristic parameters with the wall angle is similar to that of the wall distance. Under Pinj = 40 MPa, as the wall angle increases from 0° to 70°, the time to reach luminance saturation advances from 0.60 ms to 0.27 ms. Under higher Pinj = 100 MPa, a complete misfire occurs at θ =0° but bright flames are observed at θ =30-70°. With the increase of wall distance, the mean flame temperature increases due to reduced wall cooling. Coupled with the expanded flame area and combustion duration, the high-temperature region (>1800K) of soot distribution and KL factor increase significantly, especially in the range of Lw = 40-50 mm.

Opposite Sensing Response of Heterojunction Gas Sensors Based on SnO2-Cr2O3 Nanocomposites to H2 against CO and Its Selectivity Mechanism.

Metal oxide semiconductor (MOS) gas sensors show poor selectivity when exposed to mixed gases. This is a challenge in gas sensors and limits their wide applications. There is no efficient way to detect a specific gas when two homogeneous gases are concurrently exposed to sensing materials. The p-n nanojunction of xSnO2-yCr2O3 nanocomposites (NCs) are prepared and used as sensing materials (x/y shows the Sn/Cr molar ratio in the SnO2-Cr2O3 composite and is marked as SnxCry for simplicity). The gas sensing properties, crystal structure, morphology, and chemical states are characterized by employing an electrochemical workstation, an X-ray diffractometer, a transmission electron microscope, and an X-ray photoelectron spectrometer, respectively. The gas sensing results indicate that SnxCry NCs with x/y greater than 0.07 demonstrate a p-type behavior to both CO and H2, whereas the SnxCry NCs with x/y < 0.07 illustrate an n-type behavior to the aforementioned reduced gases. Interestingly, the SnxCry NCs with x/y = 0.07 show an n-type behavior to H2 but a p-type to CO. The effect of the operating temperature on the opposite sensing response of the fabricated sensors has been investigated. Most importantly, the mechanism of selectivity opposite sensing response is proposed using the aforementioned characterization techniques. This paper proposes a promising strategy to overcome the drawback of low selectivity of this type of sensor.

Random composites of nickel networks supported by porous alumina toward double negative materials.

Random composites with nickel networks hosted randomly in porous alumina are proposed to realize double negative materials. The random composite for DNMs (RC-DNMs) can be prepared by typical processing of material, which makes it possible to explore new DNMs and potential applications, and to feasibly tune their electromagnetic parameters by controlling their composition and microstructure. Hopefully, various new RC-DNMs with improved performance will be proposed in the future.