Search

In the context of urbanization and rapid pace of population aging, an increasing number of older adults has moved out of their place of origin. The elderly migrants, who involve in both geographic mobility and population aging, have become an important focus of academic research and social governance. Focusing on the elderly migrants in China, this paper outlines the current status of research on the elderly migrants around the new century, especially in the past decade（2011-2022）, which includes such dimensions as social adaptation and integration, health status and the accessibility and availability of public health services, social security, and social governance. By doing a systematic review of the existing literature, it also elaborates on the limitations of exiting research in terms of research theories, perspectives, and contents. In addition, this paper analyzes the challenges brought by the elderly migrants to the social governance of receiving cities, and reflects on the future academic research and governance strategies. It proposes that localizing theoretical innovation in academic research, improving the top-level design of urban governance, integrating elderly migrants into the governance of receiving cities and improving urban governance planning, as well as enhancing the digital literacy of elderly are necessary in order to improve the well-being of the elderly migrants and enhance their sense of happiness. [ABSTRACT FROM AUTHOR]

BACKGROUND: Polyether ether ketone has the advantages of elastic modulus close to human cortical bone, good ray transmission, chemical stability, and biocompatibility. Polyether ether ketone is expected to be applied in the field of oral implants. However, polyether ether ketone is bioinert and is difficult to integrate with surrounding bone tissue. Therefore, how to improve the surface bioactivity of polyether ether ketone remains a major issue. OBJECTIVE: To analyze the osteogenic and vasogenic effects of polyether ether ketone surface bone forming peptide 1 and polydopamine composite coating. METHODS: Polyether ether ketone titanium sheets were immersed in dopamine solution for 24 hours to prepare polyether ether ketone-polydopamine materials. Polyether ether ketone-polydopamine material was immersed in the bone forming peptide 1 solution for 24 hours to prepare polyether ether ketonepolydopamine-bone forming peptide 1 material. The micromorphology, hydrophilicity, and elemental composition of the material were characterized. Bone marrow mesenchymal stem cells were injected on the surface of polyether ether ketone, polyether ether ketone-polydopamine, and polyether ether ketonepolydopamine-bone forming peptide-1 materials. Cell viability and adhesion status were evaluated by live/dead cell staining and cytoskeleton staining. Cellular osteogenic differentiation ability was detected by alizarin red and osteocalcin immunofluorescence staining. Human umbilical vein endothelial cells were inoculated on the surface of three groups of materials. Cell viability and angiogenesis level were assessed by live/dead cell staining and immunofluorescence staining of cytoskeleton/vascular endothelial growth factor. RESULTS AND CONCLUSION: (1) Under scanning electron microscope, the surface of polyether ether ketone material was smooth; the surface of polyether ether ketone-polydopamine material had uneven deposits, and the surface of polyether ether ketone-polydopamine-bone forming peptide 1 material had small particles protruding. The results of contact angle test showed that the hydrophilicity of polyether ether ketone-polydopamine-bone forming peptide-1 material was better than the other two materials. X-ray photoelectron spectroscopy results showed that bone forming peptide 1 had been successfully modified on the surface of polyether ether ketone material. (2) Live/dead cell staining and cytoskeleton staining exhibited that compared with the other two materials, polyether ether ketone-polydopamine-bone-forming peptide 1 material could improve the viability and adhesion of bone marrow mesenchymal stem cells. Alizarin red and osteocalcin immunofluorescence staining showed that compared with the other two materials, polyether ether ketonepolydopamine-bone forming peptide-1 materials could promote the osteogenic differentiation of bone marrow mesenchymal stem cells. (3) Live/dead cell staining and immunofluorescence staining showed that compared with the other two materials, polyether ether ketone-polydopamine-bone forming peptide 1 material could improve the viability and adhesion of human umbilical vein endothelial cells and the expression of vascular endothelial growth factor protein. (4) The results show that the modification of bone forming peptide 1 and polydopamine composite coating on polyether ether ketone surface can improve the osteogenesis and angiogenesis. [ABSTRACT FROM AUTHOR]

Pre-eclampsia is a pregnancy-specific disease and a leading cause of maternal and perinatal death. Until now, no hypothesis can fully explain the pathological changes of pre-eclampsia, which is characterized by early placental trophoblast infiltration and decreased spiral artery remodeling. ACVR2A (activin A receptor type 2A), a member of the transforming growth factor β (TGF-β) receptor family, is considered as an important regulator of reproductive function, especially in the process of decidualization, trophoblast cell infiltration and placental formation. Recent studies have shown that activin A and its receptor play an important regulatory role in the occurrence and development of pre-eclampsia. This paper reviews the relationship between ACVR2A and pre-eclampsia, aiming to provide a new theoretical basis for the pathogenesis, early diagnosis and treatment of pre-eclampsia. [ABSTRACT FROM AUTHOR]

BACKGROUND: Titanium as a bone substitute material has been widely used in the field of oral implant devices, but its bioinert would affect the stable combination with bone tissue at the early stage of implantation. Therefore, exploring to improve the osteogenic properties of titanium through surface modification is necessary. OBJECTIVE: To investigate the effect of composite coating of aspirin loaded chitosan nanoparticles and polydopamine on the viability of osteoblasts in vitro. METHODS: The titanium sheets modified by polydopamine coating as well as aspirin loaded chitosan nanoparticles and polydopamine composite coating were constructed. The surface morphology and microstructure of the coatings were characterized by scanning electron microscopy. In vitro sustained-release properties of aspirin nanosphere coatings on pure titanium were detected. Rat bone marrow mesenchymal stem cells were seeded and cultured on the pure titanium sheet and the two kinds of modified titanium sheets. The spreading morphology of rat bone marrow mesenchymal stem cells on the surface of titanium sheets was observed by cytoskeleton staining. Cell proliferation was determined by CCK-8 assay. The osteogenic differentiation of rat bone marrow mesenchymal stem cells on titanium sheets was measured using alkaline phosphatase staining and immunofluorescence staining. RESULTS AND CONCLUSION: (1) Scanning electron microscope images showed that the pure titanium surface was relatively smooth, and deposits as well as grain appeared after the dopamine polymerization. Aspirin microspheres were spherical with uniform size distribution. The hydrophilicity of the nanoparticles immobilized titanium surfaces and the polydopamine coating modified titanium surfaces were better than that of the pure titanium sheets (P < 0.05). The aspirin appeared to be slow and sustained under the encapsulation of chitosan nanoparticles. (2) As observed by cytoskeleton staining, the cells showed insufficient cell expansion on the surface of the pure titanium sheets and formed a few filopodia on the dopamine modified titanium sheets. The cells on nanoparticles modified sheets showed perfect expansion. (3) CCK-8 assay showed that the titanium sheets had no obvious cytotoxicity, and the cell proliferation rate of the nanoparticles modified titanium sheets displayed higher rates of proliferation than that of the dopamine coated and pure titanium sheets with increasing cell culture time (P < 0.05). (4) Alkaline phosphatase activity was highest on the surfaces of nanoparticles modified sheets. Immunofluorescence showed that the fluorescence intensity of alkaline phosphatase was strongest. (5) The results showed that the sustained-release coating of aspirin loaded chitosan nanoparticles on the titanium surfaces could enhance the proliferation and adhesion of rat bone marrow mesenchymal stem cells and promote osteogenic differentiation. [ABSTRACT FROM AUTHOR]

A 15% lambda-cyhalothrin microcapsule suspension of polyurea resin was prepared as a capsule material by interfacial polymerization. In the preparation of lambda-cyhalothrin microcapsule suspension, the initial oil-water ratio (Ri) was obtained by the quotient of the weight of the oil phase and the weight of the initial water. The effect of the Ri value on the physico-chemical properties of the lambda-cyhalothrin microcapsule suspension was also investigated. Four 15% lambda-cyhalothrin microcapsule suspensions treated with different initial oil-water ratios were prepared. Their Ri values were 1 : 0.55, 1 : 0.69, 1 : 0.83 and 1 : 0.97, respectively. The morphology of the microcapsules was characterized by optical microscope (OM), scanning electron microscope (SEM) and laser particle size analyzer. The encapsulation efficiency and storage stability of each treatment were determined. The experimental results showed that, when the Ri values were 1 : 0.83 and 1 : 0.97, the 15% lambdacyhalothrin microcapsule suspension had high capsule quality, good microcapsule morphology, and the microcapsule encapsulation efficiency was 90% or higher. The particle sizes were in the range of 3-4 μm (D95), and the storage stability has also be qualified. This study has provided a reference for the preparation of lambda-cyhalothrin microcapsule suspensions. [ABSTRACT FROM AUTHOR]