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Ti2AlC/TiAl composites with different volume fractions were prepared by hot pressing technology, and their reinforced structural characteristics and mechanical properties were evaluated. The results showed that when the reinforced phase volume fraction of Ti2AlC was 20%, three-dimensional interpenetrating network structures were formed in the composites. Above 20%, Ti2AlC phase in the composites accumulated and grew to form thick skeletal networks. The microplastic deformation behavior of Ti2AlC phase, such as kink band and delamination, improved the fracture toughness of the composites. Comparative analysis indicated that the uniform and small interconnecting network structures could further reinforce the composites. The bending strengths of composites prepared with 20 vol.% Ti2AlC reached (900.9±45.0) MPa, which was 25.5% higher than that of TiAl matrix. In general, the co-continuous Ti2AlC/TiAl composite with excellent mechanical properties can be prepared by powder metallurgy method.

Background Osteoporosis seriously disturbs the life of people. Meanwhile, inhibition or weakening of osteogenic differentiation is one of the important factors in the pathogenesis of osteoporosis. It was reported that miR-27a-3p reduced the symptoms of osteoporosis. However, the mechanism by which miR-27a-3p in osteogenic differentiation remains largely unknown. Methods To induce the osteogenic differentiation in MC3T3-E1 cells, cells were treated with osteogenic induction medium (OIM). RT-qPCR was used to evaluate the mRNA expression of miR-27a-3p and CRY2 in cells. The protein levels of CRY2, Runt-related transcription factor 2 (Runx2), osteopontin (OPN), osteocalcin (OCN) and the phosphorylation level of extracellular regulated protein kinases (ERK) 1/2 in MC3T3-E1 cells were evaluated by western blotting. Meanwhile, calcium nodules and ALP activity were tested by alizarin red staining and ALP kit, respectively. Luciferase reporter gene assay was used to analyze the correlation between CRY2 and miR-27a-3p. Results The expression of miR-27a-3p and the phosphorylation level of ERK1/2 were increased by OIM in MC3T3-E1 cells, while CRY2 expression was decreased. In addition, OIM-induced increase of calcified nodules, ALP content and osteogenesis-related protein expression was significantly reversed by downregulation of miR-27a-3p and overexpression of CRY2. In addition, miR-27a-3p directly targeted CRY2 and negatively regulated CRY2. Meanwhile, the inhibitory effect of miR-27a-3p inhibitor on osteogenic differentiation was reversed by knockdown of CRY2 or using honokiol (ERK1/2 signal activator). Furthermore, miR-27a-3p significantly inhibited the apoptosis of MC3T3-E1 cells treated by OIM. Taken together, miR-27a-3p/CRY2/ERK axis plays an important role in osteoblast differentiation. Conclusions MiR-27a-3p promoted osteoblast differentiation via mediation of CRY2/ERK1/2 axis. Thereby, miR-27a-3p might serve as a new target for the treatment of osteoporosis.

Background Owing to neurite promoting, antioxidant and anti-inflammatory effects of Euxanthone (Eux), the investigation was aimed to probe the neuroprotective efficacy of Eux against traumatic spinal cord injury (t-SCI) in rats and whether Eux can improve neuropathic function in t-SCI. Method Sprague-Dawley (SD) rats were randomized in – Sham, t-SCI, Eux30, and Eux60 (t-SCI + 30 and 60 mg/kg respectively). Animals with compression force-induced t-SCI were subjected to estimation of locomotor functions. Spinal cord water content and Evans blue (EB) effusion were determined for quantifying edema and intactness of the spinal cord. Oxidative stress and immunochemical markers were quantified by ELISA and western blotting. Results Findings revealed that Eux60 group animals had greater Basso, Beattie, and Bresnahan (BBB) and (incline plane test) IPT score indicating improved locomotor functions. There was a reduction in the spinal edema and water content after Eux treatment, together with lowering of oxidative stress markers. The expression of IL-6, IL-12, IL-1β, caspase-3, RANKL, TLR4, NF-κB, p-38, PI3K, and Akt in spinal cord tissues of t-SCI-induced rats was lowered after Eux treatment. Conclusion Overall, the investigation advocates that Eux attenuates t-SCI and associated inflammation, oxidative damage, and resulting apoptosis via modulation of TLR4/NF-κB/p38 and PI3K/Akt signaling cascade.

Lignin is the main component of biomass with a complex, heterogeneous, three-dimensional polymeric structure of three main monolignols ( p -coumaryl, coniferyl, and sinapyl alcohol). In order to understand the pyrolysis mechanism of lignin and identify the chemical pathways for the formations of key products during pyrolysis, the pyrolysis processes of β -O-4 type lignin dimer model compound 1 (1-phenyl-2-phenoxy-1,3-propanediol) were theoretically investigated by employing density functional theory (DFT) methods at the B3LYP/6-31G(d,p) level. Based on related experimental and calculation results of bond dissociation energies of β -O-4 type lignin dimer, three possible pyrolytic pathways (the homolytic cleavage of C β O bond, the homolytic cleavage of C α C β bond and the concerted reactions) were proposed, the activation energies of each reaction step were calculated, and the temperature effect on pyrolysis processes was analyzed. The calculation results indicate that the homolytic cleavage reaction of C β O bond and concerted reaction pathways (3) could be the major reaction channels, and the homolytic cleavage reaction of C α C β bond and concerted reaction pathways (1) and (2) could be the competitive reaction channels in pyrolysis processes. The concerted reactions would dominate over free-radical homolytic reactions at lower temperatures, while at high temperatures the free-radical reaction (C O homolysis) would dominate over the concerted reactions.

Staphylococcus aureus (S. aureus) is the most common organism causing osteomyelitis, and Staphylococcus aureus protein A (SpA) is an important virulence factor anchored in its cell wall. However, the precise mechanisms underlying the bone loss caused by SpA have not been well understood. The present study aimed to investigate the effect of SpA on osteoclast differentiation, and the probable mechanism was investigated. Raw264.7 cells were treated with SpA in the absence or presence of receptor‑activated (NF)‑κB ligand for 5 days, and morphological and biochemical assays were used to assess osteoclastogenesis and explore the underlying mechanisms. Data demonstrated that SpA induced osteoclast differentiation and promoted bone resorption in a dose‑dependent manner in the absence or presence of RANKL. In addition, the expression of osteoclast‑specific genes, such as the tartrate resistant acid phosphatase, matrix metalloproteinase‑9, cathepsin K, calcitonin receptors and d2 isoform of the vacuolar ATPase Vo domain, were enhanced by SpA. Furthermore, the SpA‑induced osteoclast differentiation was associated with the degradation of inhibitor of κB‑α, phosphorylation of NF‑κB p65 and increased expression of nuclear factor of activated T‑cells. However, by treatment with JSH‑23, an NF‑κB inhibitor, the formation of osteoclast‑like cells and resorption pits was significantly reduced, and the expression of osteoclast‑specific genes was also inhibited. Collectively, in the present study SpA induced osteoclast differentiation, promoted bone resorption, and the NF‑κB signaling pathway was involved in this process.

The pyrolysis of syringol as lignin model compound was investigated using density functional theory methods at B3LYP/6-31G++ (d, p) level. Three possible pyrolytic pathways were proposed and the equilibrium geometries of the reactants, transition states, intermediate and products were fully optimized. The standard kinetic parameters in each reaction pathway were calculated and the formation and evolution mechanism of main pyrolysis products were analyzed. Bond dissociation energies calculation results show that the bond dissociation energy of CH 3 -O of syringol is the lowest and the order of all kinds of bond dissociation energy is CH 3 -O 3 O-C aromatic 2 -H aromatic aromatic -H. In reaction pathway (1) and (2), the main pyrolysis product is 3-methoxycatechol and 2-methoxy-6-methylphenol, respectively. The total energy barrier is 366.6 and 474.8 kJ/mol in pathway (1) and (2), respectively. For reaction pathway (3), the total energy barrier of o-methoxyphenol formation is as low as 21.4 kJ/mol, which shows that addition of hydrogen to the carbon atom connected with methoxyl can effectively lower the reaction energy barrier of demethoxy reaction of lignin model syringol.

Co-silica nanotubes were prepared with nanofibers of [Co(NH3)6](HCO3)(CO3)·2H2O as templates. The yield and morphology of Co-silica nanotubes were influenced by the pH value of the ammonia solution, the concentration of the Co salt solution as well as the rate of ethanol addition. The optimized sample contains 100% nanotubes with 150 – 300 nm in diameter and up to 30 -m in length.

Ovarian cancer is one of the most common malignancies encountered in the world. In ovarian cancer tissues of patients, NEU1 was expressed in a higher level than that in adjacent normal tissues. In this research, we aimed to elucidate the role of NEU1 siRNA on proliferation, apoptosis, and invasion of OVCAR3 and SKOV3 cells which expressed NEU1 notably. By cell viability assay and flow cytometry method, we found that NEU1 siRNA effectively inhibited the cancer proliferation, arrested cells cycle at G0/G1 phase, and induced apoptosis when compared to the Mock group. Result of transwell assay showed that invasion of cells in OVCAR3 and SKOV3 treated with NEU1 siRNA were suppressed significantly. Gene set enrichment analysis showed that lysosome and oxidative phosphorylation related signal pathway were associated with the NEU1 expression. In addition, Western blot revealed that expressions of Cln3 and Cln5 were depressed, and ATP5B and ATP5J expressions were also reduced. In conclusion, NEU1 siRNA can effectively inhibit proliferation, apoptosis, and invasion of human ovarian cancer cells by targeting lysosome and oxidative phosphorylation signaling, which can serve as a new target ovarian cancer treatment.

To investigate the reversal effect of MDR1 and MDR3 gene silencing on resistance of A2780/taxol cells to paclitaxel.shRNA plasmid vector specifically targeting MDR1 and MDR3 genes was transfected into A2780/taxol cells. The early stage cell apoptosis and the effect of intracellular rhodamine 123 (Rh123) accumulation were detected by flow cytometry (FCM). The late stage cell apoptosis rate was detected by terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL). The 50% inhibition concentration (IC(50)) of paclitaxel on A2780/taxol cells was determined by methyl thiazolyl tetrazolium (MTT) assay. MDR1 and MDR3 mRNA were assessed by RT-PCR, and caspase-3 protein was detected by western blot.After treatment with MDR1 and MDR3 shRNA plasmid vector, early apoptosis rate of A2780/taxol cells was (20.21 +/- 0.56)% and (10.87 +/- 1.24)%, respectively. MDR1 and MDR3 shRNA could increase cellular Rh123 accumulation (116.6 +/- 8.1 and 98.4 +/- 3.8, respectively). The late stage apoptosis rates detected by TUNEL displayed the same tendency as FCM results did. The IC(50) for paclitaxel of A2780/taxol cells was decreased significantly. The mRNA levels of MDR1 and MDR3 in A2780/taxol cells were decreased by (73.3 +/- 0.8)% and (51.6 +/- 0.4)% of control, and the reduction of MDR1 and MDR3 mRNA was in a time-dependent manner. The expression of caspase-3 protein of MDR1 and MDR3 shRNA vector transfected group in A2780/taxol cells was significantly increased [(80.8 +/- 2.6)% and (72.0 +/- 4.7)%, respectively].MDR1 and MDR3 gene silencing could recover sensitivity of A2780/taxol cells to paclitaxel and induce cell apoptosis, thus reversing cell resistance to paclitaxel.

To study the effects of ropivacaine on the duration of labor and mode of delivery in the primigravidas using patient-controlled epidural analgesia (PCEA).Retrospective analysis was performed. The 190 healthy, full-term, and single-fetus parturient primigravidas who received PCEA with 0.1% ropivacaine + fentanyl (1 microg/ml) were in the epidural analgesia group. Another 222 primigravidas who did not receive PCEA were in the control group. The duration of labor and modes of delivery, and the neonatal Apgar scores in both two groups were recorded and evaluated.Those in the epidural analgesia group experienced a significantly longer first stage [(426 +/- 161) minutes], longer second stage [(54 +/- 27) minutes] and longer full duration of delivery [(489 +/- 166) minutes] than those in the control one [(409 +/- 170) minutes, (364 +/- 167) minutes and (37 +/- 22) minutes]. The rate of using pitocin in the epidural analgesia group (30.2%) was significantly higher than that in the control group (4.1%). The cesarean section rate in epidural analgesia group (20.0%) was lower than that in the control one (28.4%); while the rate of instrumental delivery in the epidural analgesia group (20.0%) was significantly higher than that in the control one (6.3%). In summary, there were significant differences between two groups in the duration of labor, the rate of using pitocin, the rate of instrumental delivery and the rate of cesarean section. But there were no differences found for those newborn who had Apgar scores less than 7 at the point of both one and five minutes (7.9% and 4.5%, 2.6% and 0.5% respectively).Epidural ropivacaine labor analgesia lengthens the duration of labor and increases the rate of instrumental delivery, but it has no significant negative effects on the neonates.