Vibration analysis of the beam structure under the moving mass

Analytical solution of vibration of simply supported beam under the action of centralized moving mass and two numerical methods using life and death element method and displacement contact method are analyzed in this paper. The results show that vertical acceleration resulted from speed and centrifugal acceleration resulted from load moving must be taken into consideration for large quality and high speed. The characteristics and applicable situations of the two numerical methods are also studied to provide a basis for analyzing and considering structural dynamic problems of moving load mass

Single cell atlas for 11 non-model mammals, reptiles and birds.

The availability of viral entry factors is a prerequisite for the cross-species transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Large-scale single-cell screening of animal cells could reveal the expression patterns of viral entry genes in different hosts. However, such exploration for SARS-CoV-2 remains limited. Here, we perform single-nucleus RNA sequencing for 11 non-model species, including pets (cat, dog, hamster, and lizard), livestock (goat and rabbit), poultry (duck and pigeon), and wildlife (pangolin, tiger, and deer), and investigated the co-expression of ACE2 and TMPRSS2. Furthermore, cross-species analysis of the lung cell atlas of the studied mammals, reptiles, and birds reveals core developmental programs, critical connectomes, and conserved regulatory circuits among these evolutionarily distant species. Overall, our work provides a compendium of gene expression profiles for non-model animals, which could be employed to identify potential SARS-CoV-2 target cells and putative zoonotic reservoirs

Autologous Red Blood Cell Delivery of Betamethasone Phosphate Sodium for Long Anti-Inflammation

Although glucocorticoids are highly effective in treating various types of inflammation such as skin disease, rheumatic disease, and allergic disease, their application have been seriously limited for their high incidence of side effects, particularly in long term treatment. To improve efficacy and reduce side effects, we encapsulated betamethasone phosphate (BSP) into biocompatible red blood cells (RBCs) and explored its long acting-effect. BSP was loaded into rat autologous erythrocytes by hypotonic preswelling method, and the loading amount was about 2.5 mg/mL cells. In vitro, BSP loaded RBCs (BSP-RBCs) presented similar morphology, osmotic fragility to native RBCs (NRBCs). After the loading process, the loaded cells can maintain around 70% of Na+/K+-ATPase activity of natural cells. In vivo, a series of tests including survival, pharmacokinetics, and anti-inflammatory effect were carried out to examine the long-acting effect of BSP-RBCs. The results shown that the loaded cells could circulate in plasma for over nine days, the release of BSP can last for over seven days and the anti-inflammatory effect can still be observed on day 5 after injection. Totally, BSP-loaded autologous erythrocytes seem to be a promising sustained releasing delivery system with long anti-inflammatory effect

Cationic Polyphosphazene Vesicles for Cancer Immunotherapy by Efficient in Vivo Cytokine IL-12 Plasmid Delivery

To circumvent the severe toxicity of the systemic delivery of IL-12 protein and the limits of local administration of IL-12 gene, we constructed a polymersome system for systemic delivery of recombinant murine IL-12 plasmid (pmIL-12) based on amphiphilic polyphosphazenes containing weakly cationic N,N-diisopropylethylene­diamine (DPA) as hydrophobic groups and monomethoxy poly­(ethylene glycol) (mPEG) as hydrophilic tails. By simple dialysis method, pmIL-12 was successfully loaded into polymersomes due to the combination effect of physical encapsulation and electrostatic interaction. This pmIL-12 polymersome delivery system was validated with good biocompatibility and stability despite of serum protein and DNase challenging. The results of in vivo antitumor experiments showed that intravenous injection of pmIL-12 polymersomes achieved significant suppression of tumor growth in BALB/c mice bearing CT-26 colon carcinoma. The analysis revealed that the mechanism was related to the antitumor immune response induced by efficient transfection of pmIL-12 polymersomes, which maybe involved lymphocytes infiltration and angiogenic inhibition at the tumor site

Waterborne exposure to low concentrations of BDE-47 impedes early vascular development in zebrafish embryos/larvae

Polybrominated diphenyl ethers (PBDEs) are persistent flame retardants ubiquitously existing in various environment matrices. In spite of a recent reduction in use according to the phase-out policy, high levels of PBDEs are still found in both environmental and biological samples due to their persistent property and large-scale production over a long history. Developmental toxicity is a major health concern of PBDEs. However, the impact of PBDE exposure on vascular development remains poorly understood. In this study, we investigated the effect of low concentrations of 2,2',4,4'-Tetrabromodiphenyl ether (BDE-47), a predominant PBDE congener, in environmental matrices and biota, on early vascular development using zebrafish. Zebrafish embryos were continuously exposed to waterborne BDE-47 at 0.06, 0.2, 0.6 mu M starting from 2 h post-fertilization (hpf). Fluorescent images of vasculatures in Tg(kdrl:eGFP) zebrafish were acquired using a confocal microscope. The results indicated that BDE-47 exposure had no effect on hatching rate, survival, body weight, body length or heart rate in the early stage within 72 hpf, whereas zebrafish exposed to BDE-47 exhibited impairments in the growth of multiple types of blood vessels. The percentage of completed intersegmental vessels (ISV) at 30 hpf decreased in embryos treated with BDE-47 in a dose-dependent fashion. BDE-47 exposure led to a slight decrease in the growth of common cardinal vein (CCV), while dramatically hindered CCV remodeling process reflected by the larger CCV area and wider ventral diameter. BDE-47 exposure significantly reduced sub-intestinal vessels (SIV) area as well as the vascularized yolk area in zebrafish larvae at 72 hpf. In addition, the expression of genes related to vascular growth and remodeling was markedly suppressed in BDE-47-exposed zebrafish. These findings demonstrate the adverse effects of BDE-47 on early vascular development, and confirm the vascular toxicity of PBDEs in vivo. The results indicate that developing vasculature in zebrafish is sensitive to BDE-47 exposure, and may serve as a powerful tool for the assessment of early exposure to PBDEs

A comparative study of high- and low-Al2O3 fly ash based-geopolymers: the role of mix proportion factors and curing temperature

Developing sustainable and low-CO2 emission construction materials is of essential importance for reducing the environmental footprint of cement industry. In this work, ordinary circulating fluidized bed combustion fly ashes with different Al2O3 concentrations were used to prepare geopolymer. Upon XRD, SEM, FTIR and TG/DSC characterizations, the factors, including Si/Al ratio, the additional water/solid ratio, modulus of alkali activator (molar ratio of SiO2/Na2O) and curing temperature, had been investigated to reveal their influences to the mechanical and microstructural properties of geopolymers. For low-Al2O3 fly ash, the optimal synthesis conditions (curing temperature = 80 °C, Si/Al = 2:1, modulus = 1.5, additional water/solid ratio = 0.1) were obtained. Geopolymers modified with high-Al2O3 fly ash possess superior performance than that of low-Al2O3 fly ash modified samples, in terms of compressive strength and microstructure. This study proves that the application of lowAl2O3 fly ash can be used as a substitute material for geopolymer cement manufacture

Regulation of bone and fat balance by Fructus Ligustri Lucidi in ovariectomized mice

AbstractContext Fructus Ligustri Lucidi (FLL), a commonly used herb of traditional Chinese medicine (TCM), is the fruit of Ligustrum lucidum Ait. (Oleaceae). The ethanol extract of FLL is a potential candidate for preventing and treating postmenopausal osteoporosis (PMOP) by nourishing the liver and kidneys.Objective This study determines whether an ethanol extract of FLL has anti-osteoporotic effects in ovariectomized (OVX) mice and explores the underlying mechanism.Materials and methods The OVX model of eight-week-old C57BL/6J female mice was taken, and ovariectomy was used as PMOP. Mice were divided into five groups: sham-operated group (n = 10), OVX group (n = 10), OVX + E2 group (n = 10; 0.039 mg/kg), OVX + FLL group (n = 10; 2 g/kg) and OVX + FLL group (n = 10; 4 g/kg). Mice were treated by gavage with FLL or CMCNa once daily for 8 weeks. We harvested uteri, femur, and tibias from mice; bone mineral density (BMD) and bone microstructure were obtained by X-ray absorptiometry and micro-CT. Furthermore, the effect of FLL on the balance of osteoblast and adipocyte differentiation was investigated using bone marrow mesenchymal stem cells (BMMSCs).Results The results indicated that FLL did not affect OVX-induced estradiol reduction. Compared with OVX mice, FLL significantly increased BMD (63.54 vs. 61.96), Conn. D (86.46 vs. 57.00), and left tibial strength (13.91 vs. 11.27), decreased Tb. Sp (0.38 vs. 0.44) and body fat content (4.19% vs. 11.24%). FLL decreased osteoclast activity and enhanced RUNX2 expression; inhibited perilipin peroxisome proliferator-activated receptor gamma (PPARγ) expression and adipocyte differentiation from BMMSCs.Conclusions FLL prevented additional bone loss and improved bone microstructure in OVX mice by modulating bone and fat balance, suggesting that FLL might be a therapeutic agent for PMOP