Effects of Pollen Typhae Total Flavone On β-Arrestin-2/SRC/ AKT signaling in adipose tissues of Type 2 diabetic rats

Background: Pollen Typhae total flavone (PTF), the extract from Pollen Typhae, a Chinese herbal medicine,  has been reported to improve insulin resistance in type 2 diabetic rats, but the potential mechanisms keep unclear.Materials and Methods: Type 2 diabetic model rats were induced by high-fat diet and low-dose  streptozotocin, and then were administered PTF by intragastrical gavage. After treatment for 4 weeks, insulin  receptor-β level in adipose tissues was determined by ELISA, and the protein expression was analyzed by  western blotting.Results: Administration of PTF increased insulin receptor-β level and enhanced β-arrestin-2 protein expression  in adipose tissues of type 2 diabetic rats. Although having no effect on the protein expression of Src  or Akt, PTF promoted phosphorylation of Src at Tyr416 and Akt at Ser473.Conclusion: The results indicate that PTF has beneficial effects on the β-arrestin-2/Src/Akt signaling in  adipose tissues of type 2 diabetic rats, implying the underlying mechanisms of PTF in ameliorating insulin  resistance.Key words: Chinese medicine, type 2 diabetes, signal transduction, insulin resistance, β-arrestin-

⁴⁰Ar/³⁹Ar geochronology, fluid inclusions, and ore‐grade distribution of the Jiawula Ag–Pb–Zn deposit, NE China: implications for deposit genesis and exploration

The Jiawula Ag–Pb–Zn deposit is located in the northern part of the Great Xing'an Range metallogenic belt within the eastern segment of the Central Asian Orogenic Belt. Here, we report results from muscovite ⁴⁰Ar/³⁹Ar geochronology and fluid inclusion study and formulate a vertical projection map of the ore grade in this deposit. The muscovite from the Jiawula deposit yields a plateau age of 133.27 ± 0.66 Ma and a ⁴⁰Ar/³⁹Ar isochron age of 131.88 ± 0.83 Ma. The muscovite ⁴⁰Ar/³⁹Ar data indicate a discrete second hydrothermal event postdating the mineralization, which we correlate with post‐collisional extension after the subduction direction of the Palaeo‐Pacific Plate changed. Low‐salinity aqueous fluid inclusions in quartz from the Jiawula deposit represent meteoric water or groundwater. Based on the fluid inclusion study, the fluids were trapped during cooling and decompression, which may have resulted in metal precipitation. We envisage that the copper precipitated from a high‐temperature fluid in the southern domain whereas lead, zinc, and silver precipitated at a lower temperature in the north. The spatial distribution of the ore‐forming elements, therefore, reflects the ore fluid migration‐cooling path from the south to north

Fatigue Properties and Damage Mechanism of a Cr-Mn Austenite Steel

The fatigue properties and the damage mechanism of a Cr-Mn austenite steel were investigated using four-point bend fatigue testing. The stress-number of cycles to failure (S-N) curve of the Cr-Mn austenite steel was measured at room temperature, at the frequency of f=20 Hz and the stress ratio of R=0.1. The fatigue strength of this Cr-Mn austenite steel was measured to be 503 MPa in the maximum stress. Multiple cracks are initiated on the sample surface after fatigue failure tests, and usually only one or two of them can lead to the final failure of the samples. Most of the cracks are initiated at the {111 }primary slip bands, especially within coarse grains. When a fatigue crack meets a new grain, it adapts to slip bands in this grain and hardly extends along the foregoing route in the previous grain. A crack is deflected at a grain boundary by crack plane twisting and tiling on the grain boundary plane, causing fracture steps on the fracture surface

Mobile communication base station antenna measurement using unmanned aerial vehicle

Traditional base station antenna measurement methods conducted with professional worker climbing towers tend to raise safety and inefficiency concerns in practical application. Designed to address the above problems, this paper proposes an intelligent and fully automatic antenna measurement unmanned aerial vehicle (UAV) system for mobile communication base station. Firstly, an antenna database, containing 19,715 images, named UAV-Antenna is constructed by image capturing with the help of UAVs flying around various base stations. Secondly, Mask R-CNN is adopted to train an optimal instance segmentation model on UAV-Antenna. Then, pixel coordinates and threshold are utilized for measuring antenna quantity and separate all antenna data for further measuring. Finally, a least squares method is employed for measuring antenna parameters. Experimental results show that the proposed method can not only satisfy the industry application standards, but also guarantee safety of labors and efficiency of performance

Rashbons: Properties and their significance

In presence of a synthetic non-Abelian gauge field that induces a Rashba like spin-orbit interaction, a collection of weakly interacting fermions undergoes a crossover from a BCS ground state to a BEC ground state when the strength of the gauge field is increased [Phys. Rev. B {\bf 84}, 014512 (2011)]. The BEC that is obtained at large gauge coupling strengths is a condensate of tightly bound bosonic fermion-pairs whose properties are solely determined by the Rashba gauge field -- hence called rashbons. In this paper, we conduct a systematic study of the properties of rashbons and their dispersion. This study reveals a new qualitative aspect of the problem of interacting fermions in non-Abelian gauge fields, i.e., that the rashbon state induced by the gauge field for small centre of mass momenta of the fermions ceases to exist when this momentum exceeds a critical value which is of the order of the gauge coupling strength. The study allows us to estimate the transition temperature of the rashbon BEC, and suggests a route to enhance the exponentially small transition temperature of the system with a fixed weak attraction to the order of the Fermi temperature by tuning the strength of the non-Abelian gauge field. The nature of the rashbon dispersion, and in particular the absence of the rashbon states at large momenta, suggests a regime of parameter space where the normal state of the system will be a dynamical mixture of uncondensed rashbons and unpaired helical fermions. Such a state should show many novel features including pseudogap physics.Comment: 8 pages, 6 figure

Imperfection-Enabled Strengthening of Ultra-Lightweight Lattice Materials

\ua9 2024 The Author(s). Advanced Science published by Wiley-VCH GmbH.Lattice materials are an emerging family of advanced engineering materials with unique advantages for lightweight applications. However, the mechanical behaviors of lattice materials at ultra-low relative densities are still not well understood, and this severely limits their lightweighting potential. Here, a high-precision micro-laser powder bed fusion technique is dveloped that enables the fabrication of metallic lattices with a relative density range much wider than existing studies. This technique allows to confirm that cubic lattices in compression undergo a yielding-to-buckling failure mode transition at low relative densities, and this transition fundamentally changes the usual strength ranking from plate > shell > truss at high relative densities to shell > plate > truss or shell > truss > plate at low relative densities. More importantly, it is shown that increasing bending energy ratio in the lattice through imperfections such as slightly-corrugated geometries can significantly enhance the stability and strength of lattice materials at ultra-low relative densities. This counterintuitive result suggests a new way for designing ultra-lightweight lattice materials at ultra-low relative densities

Single-cell transcriptome landscape of ovarian cells during primordial follicle assembly in mice

Primordial follicle assembly in the mouse occurs during perinatal ages and largely determines the ovarian reserve that will be available to support the reproductive life span. The development of primordial follicles is controlled by a complex network of interactions between oocytes and ovarian somatic cells that remain poorly understood. In the present research, using single-cell RNA sequencing performed over a time series on murine ovaries, coupled with several bioinformatics analyses, the complete dynamic genetic programs of germ and granulosa cells from E16.5 to postnatal day (PD) 3 were reported. Along with confirming the previously reported expression of genes by germ cells and granulosa cells, our analyses identified 5 distinct cell clusters associated with germ cells and 6 with granulosa cells. Consequently, several new genes expressed at significant levels at each investigated stage were assigned. By building single-cell pseudotemporal trajectories, 3 states and 1 branch point of fate transition for the germ cells were revealed, as well as for the granulosa cells. Moreover, Gene Ontology (GO) term enrichment enabled identification of the biological process most represented in germ cells and granulosa cells or common to both cell types at each specific stage, and the interactions of germ cells and granulosa cells basing on known and novel pathway were presented. Finally, by using single-cell regulatory network inference and clustering (SCENIC) algorithm, we were able to establish a network of regulons that can be postulated as likely candidates for sustaining germ cell-specific transcription programs throughout the period of investigation. Above all, this study provides the whole transcriptome landscape of ovarian cells and unearths new insights during primordial follicle assembly in mice

Nitrification and inorganic nitrogen distribution in a large perturbed river/estuarine system: the Pearl River Estuary, China

We investigated the spatial distribution and seasonal variation of dissolved inorganic nitrogen in a large perturbed estuary, the Pearl River Estuary, based on three cruises conducted in winter (January 2005), summer (August 2005) and spring (March 2006). On-site incubation was also carried out for determining ammonium and nitrite oxidation rates (nitrification rates). We observed a year-round pattern of dramatic decrease in NH4+, increase in NO3-, but insignificant change in NO2- in the upper estuary at salinity similar to 0-5. However, species and concentrations of inorganic nitrogen at upper estuary significantly changed with season. In winter, with low runoff, the most upper reach of the Pearl River Estuary showed relatively low rates of ammonia oxidation (0-5.4 mu mol N L-1 d(-1)) and nitrite oxidation (0-5.2 mu mol N L-1 d(-1)), accompanied by extremely high concentrations of ammonia (up to >800 mu mol L-1) and nitrate (up to >300 mu mol L-1). In summer, the upper estuary showed higher nitrification rates (ammonia oxidation rate similar to 1.5-33.1 mu mol N L-1 d(-1), nitrite oxidation rate similar to 0.6-32.0 mu mol N L-1 d(-1)) with lower concentrations of ammonia ( <350 mu mol L-1) and nitrate ( <120 mu mol L-1). The Most Probable Number test showed relatively lower nitrifier abundance in summer at most sampling stations, indicating a greater specific nitrification rate per cell in the warm season. Temperature appeared to control nitrification rates to a large degree in different seasons. Spatial variability of nitrification rates appeared to be controlled by a combination of many other factors such as nutrient concentrations, nitrifier abundance and dissolved oxygen (DO) concentrations. In addition to aerobic respiration, nitrification contributed significantly to the consumption of DO and production of free CO2 at upper estuary. Nitrification-induced consumption accounted for up to approximately one third of the total water column community DO consumption in the upper estuary during the surveyed periods, boosting environmental stress on this large estuarine ecosystem.Natural Science Foundation of China [40521003, 40576036, 90711005, 90211020

Nanorepairers Rescue Inflammation-Induced Mitochondrial Dysfunction in Mesenchymal Stem Cells

Mitochondrial dysfunction in tissue-specific mesenchymal stem cells (MSCs) plays a critical role in cell fate and the morbidity of chronic inflammation-associated bone diseases, such as periodontitis and osteoarthritis. However, there is still no effective method to cure chronic inflammation-associated bone diseases by physiologically restoring the function of mitochondria and MSCs. Herein, it is first found that chronic inflammation leads to excess Ca2+ transfer from the endoplasmic reticulum to mitochondria, which causes mitochondrial calcium overload and further damage to mitochondria. Furthermore, damaged mitochondria continuously accumulate in MSCs due to the inhibition of mitophagy by activating the Wnt/β-catenin pathway under chronic inflammatory conditions, impairing the differentiation of MSCs. Based on the mechanistic discovery, intracellular microenvironment (esterase and low pH)-responsive nanoparticles are fabricated to capture Ca2+ around mitochondria in MSCs to regulate MSC mitochondrial calcium flux against mitochondrial dysfunction. Furthermore, the same nanoparticles are able to deliver siRNA to MSCs to inhibit the Wnt/β-catenin pathway and regulate mitophagy of the originally dysfunctional mitochondria. These precision-engineered nanoparticles, referred to as “nanorepairers,” physiologically restore the function of mitochondria and MSCs, resulting in effective therapy for periodontitis and osteoarthritis. The concept can potentially be expanded to the treatment of other diseases via mitochondrial quality control intervention