Objective To study the changes and mechanism of skin stem cells in microgravity.Methods The skin stem cells of SD rats were used to establish a suspension culture system and compare the proliferation of skin stem cells with 1G gravity.Results The simulated microgravity significantly affected the velocity of skin stem cell sphere proliferation in suspension culture,which was about 12%higher than the 1G gravity group.Transcriptome sequencing showed that 1673 genes were up-regulated and 1409 genes were downregulated;Calcium signaling;cytokine-cytokine receptor interaction and PPAR pathway were different in the two environments.Conclusion Simulation of microgravity can affect the proliferation behavior of skin stem cells in suspension culture by regulating the expression of key signaling pathways,which provides an experimental basis for further research in spatial microgravity environ ment.

Objective To investigate the effects of microgravity environment on hibernating myoblasts.Methods Hibernating myoblasts were cultured under real and simulated microgravity conditions for 10 days.RNA-seq analysis and immunofluorescence are used to analysis the impact of microgravity environment on cell growth and gene expression of myoblasts.Results Under the microgravity conditions,genes associated with proliferation were upregulated.Under simulated microgravity,there were more and higher proportion of Ki67 positive cells compared to normal gravity conditions.Conclusion The microgravity environment promotes the proliferation of hibernating myoblasts.

Poly(dimethyl siloxane)(PDMS)is suitable for the fabrication of space cell culture chips.It is necessary to perform highly stable hydrophilic modification to promote cell adhesion on PDMS surface.We modified PDMS surface by oxygen plasma treatment combining with physical adsorption in this article.PDMS,which was treated with oxygen plasma and sequentially coated with Poly-L-lysine or collagen(PLL-ox-PDMS,COL-ox-PDMS)with various solution concentration and kept in different environmental conditions,were characterized by contact angle and surface energy measurements,and atomic force microscopy(AFM).Cell growth conditions on bare PDMS and modified PDMS were compared,and the numbers of live cells cultured for 1-3 days were evaluated.Experimental results indicate that higher solution concentration and low storage temperature benefit the hydrophilicity stability.The contact angles of PLL-ox-PDMS stored in 4℃and COL-ox-PDMS were close to 60°and 65°on day 25 and 14,respectively.Both modified PDMS surfaces are suitable for cell adhesion and proliferation,and no cell layer falls offin 10 days.The modification method is especially suitable for applications such as medium and long term space cell culture.

Genetic mutations in triggering receptor expressed on myeloid cells 2 (TREM2) have been linked to a variety of neurodegenerative diseases including Alzheimer’s disease, amyotrophic lateral sclerosis, frontotemporal dementia and Parkinson’s disease. In the brain, TREM2 is highly expressed on the cell surface of microglia, where it can transduce signals to regulate microglial functions such as phagocytosis. To date, mechanisms underlying intracellular trafficking of TREM2 remain elusive. Mutations in the presenilin 1 (PS1) catalytic subunit of the γ-secretase complex have been associated with increased generation of the amyloidogenic Aβ (amyloid-β) 42 peptide through cleavage of the Aβ precursor amyloid precursor protein. Here we found that TREM2 interacts with PS1 in a manner independent of γ-secretase activity. Mutations in TREM2 alter its subcellular localization and affects its interaction with PS1. Upregulation of PS1 reduces, whereas downregulation of PS1 increases, steady-state levels of cell surface TREM2. Furthermore, PS1 overexpression results in attenuated phagocytic uptake of Aβ by microglia, which is reversed by TREM2 overexpression. Our data indicate a novel role for PS1 in regulating TREM2 intracellular trafficking and pathophysiological function.

Objective To observe the prevalence and risk factors of chronic low back pain in puerperas after childbirth.Methods Eight hundred and eighty-one puerperas were selected,among whom 459 cases had uterine-incision delivery,and 422 cases had spontaneous delivery.The age,height and weight of pregnant women,birth weight of newborn,history of preoperative low back pain,parity and mode of delivery were recorded.The rate of chronic low back pain occurring within 1 month after childbirth and continuing for 3 months was recorded by telephone.The factors with P values less than 0.05 would enter the Logistic regression analysis to screen the risk factors of chronic low back pain.Results Two hundred and fifty-nine puerperas (259/881,29.4％) appeared chronic low back pain,of whom 157 puerperas (157/459,34.2％)delivered by uterine-incision and 102 puerperas (102/422,24.2％) delivered spontaneously,and the difference was statistically significant (P ＜ 0.01).Six hundred and fifty-eight puerperas had no history of preoperative low back pain,and 150 puerperas (150/658,22.8％) appeared newly developed chronic low back pain.Logistic regression analysis showed that mode of delivery,parity and history of preoperative low back pain were the risk factors of chronic low back pain.Condusions The rate of chronic low back pain in puerperas after childbirth is 29.4％,and the newly developed chronic low back pain is 22.8％.Uterineincision delivery,multiparity and history of preoperative low back pain are the risk factors of chronic low back pain for puerperas after childbirth.

OBJECTIVETo investigate the chemical constituents of Oldenlandia diffusa.

METHODThe column chromatography with polyamide Sephadex LH -20, silica gel as packing materials and HPLC, were used to separate and purify the chemical components. The structures were elucidated on the basis of physicochemical properties and spectral data.

RESULTNine compounds were isolated and identified as 2, 6-dihydroxy-1-methoxy-3-methylanthraquinone (1), 2-hydroxy-1-methoxy-3-methylanthraquinone (2), 2-hydroxy-3-methylanthraquinone (3), quercetin-3-O-[2-O-(6-O-E-sinapoyl)-beta-D-glucopyranosyl]-beta-glucopyranoside (4), quercetin-3-O-[2-O-(6-O-E-feruloyl)-beta-D-glucopyranosyl]-beta-glucopyranoside (5), kaempferol-3-O-[2-O-(6-O-E-feruloyl)-beta-D-glucopyranosyl]-beta-galactopyranoside (6), quercetin-3-O-(2-O-beta-D-glucop-yranosyl)-beta-D-glucopyranoside (7), rutin (8) and quercertin (9).

CONCLUSIONCompounds 1 and 8 were obtained from this plant for the first time, and compound 1 was a new compound.

Anthraquinones ; chemistry ; isolation & purification ; Molecular Conformation ; Molecular Structure ; Oldenlandia ; chemistry ; Plants, Medicinal ; chemistry ; Quercetin ; chemistry ; isolation & purification ; Rutin ; chemistry ; isolation & purification

Objective To establish a carrying system for space cellular experiment suitable for astronaut to carry out cellular experiments on Shenzhou-6 mission.Methods The cell carrying sample bag,sample box and sample box integrated package were designed.Primary cardiomyocytes and osteoblasts culture and ground model experiment in the simulated environment of space cabin were performed.With man-tended,the cellular experiment was carried out on the orbit.Results After 5 d space flight,the returned cell samples were analyzed.The results demonstrated that the system was of good safety,reliability and applicability,as well as satisfied the demands of analyzed samples.Conclusion After Shenzhou-6 space flight,it is showed that this system fits for small loading,multi-cells and man-tended carrying mission,and can satisfy the demand of the first man-tended space cellular experiments carried out on the Shenzhou-6 spacecraft.

The reason for the construction of standard operation process(SOP) in equipment application and maintenance is expatiated.The content and how to construct the system are also discussed.Many problems in equipment application and management are solved.The efficiency of all kinds of equipment in the construction of mobile medical service corps are enhanced.

Objective To compare the treatment effects of self-designed anti-rotation reduction internal fixators (ARRIF), atlas fixator (AF) and Dick screw in reduction and fixation of different thoracolumbar spinal fractures. Methods Reduction effect, operation time, bleeding volume during operation and complications were observed and compared after ARRIF, AF and Dick screw were used to treat 90 cases of thoracolumbar spinal fractures. Results Compared with AF and Dick screw, the operation time of ARRIF was shorter with less bleeding volume during operation as well as less complications like broken or pulled-out screw or broken rod. Conclusions All three fixation methods can attain the reduction and fixation of various kinds of thoracolumbar spinal fractures. However, ARRIF is the most valuable transpedicular internal fixator and can more conveniently reduce and fixate the different spinal fractures and AF places the second.

By mechanical comparison study of ARRIF,Dick and AF ,their reliable basis for further clinical application was evaluated. Models of spinal fracture were made using fresh cadavers. According to the Latin squre experimental designing principle, the fracture specimens were fixed with ARRIF,Dick and AF separately. The shift and angle changes were observed under different loads,and the analysis of variance was performed to all the data with the SPSS software . The single spinal compression fracture model showed no significant shift and the mechanical features were similar when it was fixed by ARRIF,Dick and AF. The model of spinal compression fracture with three spinal damages showed significant differences among these three fixings when axial torsion load was given. ARRIF and AF were clearly superior to Dick. The histological observation of ARRIF recorded no significant changes in the bone trabecula around the nail pass and the structure kept normal. The mechanical feature of ARRIF was basically similar to that of AF and Dick. Our conclusion is that because of the characteristics of its designing, the anti-axial torsion ability of ARRIF is outstanding and it can be easily fixed in application, thus it holds certain value in clinical practice.