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Abstract Background Human adipose-derived stem cells (ADSCs) exert a strong anti-inflammatory effect, and synovium-derived stem cells (SDSCs) have high chondrogenic potential. Thus, this study aims to investigate whether a combination of human ADSCs and SDSCs will have a synergistic effect that will increase the chondrogenic potential of osteoarthritis (OA) chondrocytes in vitro and attenuate the cartilage degeneration of early and advanced OA in vitro. Methods ADSCs, SDSCs, and chondrocytes were isolated from OA patients who underwent total knee arthroplasty. The ADSCs–SDSCs mixed cell ratios were 1:0 (ADSCs only), 8:2, 5:5 (5A5S), 2:8, and 0:1 (SDSCs only). The chondrogenic potential of the OA chondrocytes was evaluated in vitro with a transwell assay or pellet culture with various mixed cell groups. The mixed cell group with the highest chondrogenic potential was then selected and injected into the knee joints of nude rats of early and advanced OA stages in vivo. The animals were then evaluated 12 and 20 weeks after surgery through gait analysis, von frey test, microcomputed tomography, MRI, and immunohistochemical and histological analyses. Finally, the mechanisms underlying these findings were investigated through the RNA sequencing of tissue samples in vivo and Western blot of the OA chondrocyte autophagy pathway. Results Among the MSCs treatment groups, 5A5S had the greatest synergistic effect that increased the chondrogenic potential of OA chondrocytes in vitro and inhibited early and advanced OA in vivo. The 5A5S group significantly reduced cartilage degeneration, synovial inflammation, pain sensation, and nerve invasion in subchondral nude rat OA, outperforming both single-cell treatments. The underlying mechanism was the activation of chondrocyte autophagy via the FoxO1 signaling pathway. Conclusion A combination of human ADSCs and SDSCs demonstrated higher potential than a single type of stem cell, demonstrating potential as a novel treatment for OA.

A deep understanding of the effects of the inorganic characteristics of Xinjiang coals on combustion particulate generation is of great significance for their clean and efficient utilization. This work investigated the inorganic characteristics of Wucaiwan coal (WCW), Wanxiang coal (WX), Tianchi coal (TC), and Xiheishan coal (XHS) and the their relationship with the production of ultrafine particulates during combustion. The results show that the four Xinjiang coals are mainly lignites with low ash and sulfur contents. Coal ashes are enriched in basic elements. Among them, the content of Na2O (3.58%−7.13%) is commonly higher than that of conventional utility coals. The ashes of WCW and WX coals have higher contents of CaO (> 33%), but low contents of SiO2 and Al2O3. WX coal is particularly characterized by high Na and Cl. The Na in coal is primarily water soluble(62.3%−90.6%). The K is mainly HCl insoluble. The Fe occurs primarily as HCl soluble and insoluble forms. And the distribution of Ca and Mg in different forms varies according to coal types. The composition of ultrafine particulate matter from Xinjiang coal combustion is dominated by Na, K, Cl, and S. The particle size range of the ultrafine particulate matter is accurately defined by using the condition that the mass fraction of Na2O+K2O+Cl+SO3 is higher than 50%. The ultrafine particulate matter of WCW, TC and XHS coals has similar particle size ranges (≤0.07 μm); while the ultrafine particulate matter of WX coal, which has the highest content of Na in the water-soluble form, has a wider particle size range (≤0.76 μm). The generation of ultrafine particulate matter (y) is found to be highly linearly and positively correlated with the total amount of water-soluble (Na+K) (x) in the coal, with the relationship equation y = 0.528x−0.239 and the correlation coefficient of 0.948.

Abstract Skeletal disorders are commonly diagnosed by X-ray imaging, but the radiation limits its use. Optical imaging through the near-infrared-II window (NIR-II, 1000–1700 nm) can penetrate deep tissues without radiation risk, but the targeting of contrast agent is non-specific. Here, we report that lanthanide-doped nanocrystals can passively target the bone marrow, which can be effective for over two months. We therefore develop the high-resolution NIR-II imaging method for bone disease diagnosis, including the 3D bone imaging instrumentation to show the intravital bone morphology. We demonstrate the monitoring of 1 mm bone defects with spatial resolution comparable to the X-ray imaging result. Moreover, NIR-II imaging can reveal the early onset inflammation as the synovitis in the early stage of rheumatoid arthritis, comparable to micro computed tomography (μCT) in diagnosis of osteoarthritis, including the symptoms of osteophyte and hyperostosis in the knee joint.

Abstract Background Calcitonin gene-related peptide (CGRP) contributes to bone formation by stimulating bone marrow stromal cell (BMSC) proliferation and differentiation. However, the proliferative and apoptotic effects of CGRP on bone marrow-derived endothelial progenitor cells (EPCs) have not been investigated. Methods We tested the effects of CGRP on EPC proliferation and apoptosis by Cell Counting Kit-8, flow cytometry, and studied the effects of CGRP on the expression of proliferation- and apoptosis-related markers in EPCs and the underlying mitogen-activated protein kinase (MAPK) signalling pathway by quantitative polymerase chain reaction and western blotting. Results We detected EPC markers (CD34, CD133 and VEGFR-2) in 7-day cultures and found that CGRP (10− 10–10− 12 M) promoted the proliferation of cultured EPCs, with a peak increase of 30% at 10− 10 M CGRP. CGRP also upregulated the expression of proliferation-associated genes, including cyclin D1 and cyclin E, and increased the percentages of G2/M-phase and S-phase cells after incubation 72 h. CGRP inhibited serum deprivation (SD)-induced apoptosis in EPCs after 24 and 48 h and downregulated the expression of apoptosis-related genes, including caspase-3, caspase-8, caspase-9 and Bax. Phosphorylated (p-)ERK1/2, p-p38 and p-JNK protein levels in EPCs treated with CGRP were significantly lower than those in untreated EPCs. Pre-treatment with the calcitonin receptor-like receptor (CRLR) antagonist CGRP8–37 or a MAPK pathway inhibitor (PD98059, SB203580 or SP600125) completely or partially reversed the pro-proliferative and anti-apoptotic effects and the reduced p-ERK1/2, p-p38 and p-JNK expression induced by CGRP. Conclusion Our results show that CGRP exerts pro-proliferative and anti-apoptotic effects on EPCs and may act by inhibiting MAPK pathways.

Neuropeptide Y (NPY) exhibits a critical but poorly understood regulatory signaling function and has been shown to promote proliferation, vascularization and migration in several types of cells and tissues. However, little is known about the specific role of NPY in the proliferation and apoptosis of bone marrow stromal cells (also known as bone marrow-derived mesenchymal stem cells, BMSCs), which contain a subpopulation of multipotent skeletal stem cells. Based on BrdU incorporation tests, Cell Counting Kit-8, flow cytometry, quantitative polymerase chain reaction and western blotting, we showed that NPY significantly promoted the proliferation of BMSCs in a concentration-dependent manner, with a maximal effect observed at a concentration of 10−10 M for pro-proliferative and 10−12 M for anti-apoptotic activities. Furthermore, NPY significantly increased the percentage of cells in S and G2/M phases. In addition, NPY exhibited a protective effect after 24 h of serum starvation as illustrated by a reduction in the apoptosis rate, degree of nuclear condensation, and expression of apoptosis markers, including caspase-3, caspase-9 and Bax mRNA expression. NPY also increased the mRNA and protein expression levels of canonical Wnt signaling pathway proteins, including β-catenin and c-myc, during the induced proliferative and anti-apoptotic processes. However, the proliferative and anti-apoptotic activities of NPY were partially blocked by both PD160170 (1 μM) and DKK1 (0.2 μg/mL). These compounds also blocked the mRNA and protein expression of β-catenin, p-GSK-3β and c-myc. Therefore, the results of the present study demonstrated that NPY exerts a proliferative and protective effect on BMSCs in a dose- and time-dependent manner in vitro, and importantly, these effects may be mediated via its Y1 receptor and involved in activation of the canonical Wnt signaling pathway.

Zhundong low-rank coal is very likely to be utilized extensively in oxy-fired boilers in the near future. Its PM10 (particulate matter with an aerodynamic diameter of ≤10 μm) emission behaviors during oxy-fuel combustion need to be carefully studied before its large-scale use. The present study examines the emission behaviors of inorganic ultrafine particles (PM0.5, with an aerodynamic diameter of ≤0.5 μm), as well as PM10 during the combustion of Zhundong coal in air and oxy-fuel conditions (O2/CO2) at three characterized O2 input fractions, i.e., 21, 27 and 32 vol.%. The combustion experiments were carried out in a high-temperature drop-tube furnace (HDTF) at a combustion temperature of 1500 °C. The results show that PM0.5 is composed of Na, S, Mg and Ca, with total fractions of ~90%, while PM0.5–10 (with an aerodynamic diameter between 0.5 and 10 μm) predominantly contains Ca (~50–65%). At three characterized oxygen fractions during oxy-fuel combustion (OXY21, 27 and 32), the promoted O2 fraction was found to increase the yields of both PM0.5 and PM0.5–10. A higher particle-burning temperature and a lower CO2 fraction promote the reactions of both organically bound elements and inorganic minerals, increasing the partitioning of Mg and Ca and causing an increased yield of PM0.5. The yield of PM0.5 from air is high and similar to that from OXY32 while the yield of PM0.5–10 from air is similar to that from OXY27. The high yield of PM0.5 from air is mainly generated by the highest yields of Ca in four conditions.

The high proportion of renewable energy and power electronic equipment is emerging as a significant trend and key characteristic of the power system development driven by the dual promotion of the energy transformation and scientific technological advancement. Major modifications have been made to the dynamic behavior of the new power system. The traditional small signal stability analysis approach is difficult to apply, and there are still urgent issues to be resolved for the quick change of operating conditions. In this paper, a Lyapunov direct analysis method of gradient dynamic deviation based on phasor measurement unit (PMU) data is proposed to analyze the small signal stability of the new power system. First, the PMU data matrix is used to reduce the dimension to obtain the low dimension matrix, which is substituted into the power system matrix model with a doubly-fed induction generator (DFIG). The diagonal matrix is obtained by solving the Lyapunov equation, and the positive definiteness of the matrix is determined to judge the system stability. Then, the dynamic deviation of corresponding state variable is calculated by solving the obtained diagonal matrix. The gradient descent method is applied to the corresponding state variable curve to iterate the extreme point value of curve. The time-weighted dynamic deviation of the whole oscillation process is calculated by time weighting, which provides guidance for the subsequent configuration position of damping stability controller, i.e., power system stabilizer (PSS). The method can improve the small interference stability of the system. The effectiveness of the fast stability analysis of the new power system is verified by simulations of the new England 10-machine 39-bus system with DFIG.