Study on Plastic Constitutive Relation and Ductile Fracture Criterion of AM60B Magnesium Alloy.

It is currently a challenge to accurately predict the deformation and fracture behavior of metal parts in automobile crashes. Many studies have shown that the deformation and fracture behavior of materials are significantly affected by the stress state during automobile crashes with complex stress state characteristics. In order to further promote the application of die-cast magnesium alloys in automobiles, it is particularly important to study the material deformation and fracture behavior of die-cast magnesium alloys. In this paper, the mechanical properties of the AM60B die-cast magnesium alloy sheet under four stress states (shear, tension, R10 notch tension, and cupping) were designed and tested. Based on the von Mises isotropic constitutive model and Swift weighted Hockett-Sherby hardening model, the plastic constitutive model of die-cast magnesium alloy was established. Based on the plastic model and the fracture model (JC, MMC, and DIEM) considering the influence of three stress states, the deformation and fracture behavior of the AM60B die-cast magnesium alloy front-end members in three-point bending were predicted by experiments and finite element simulation. The experimental results show that the deformation mode and loading-displacement curve trend of the AM60B die-cast magnesium alloy front members are the same, the crack initiation point and crack initiation time are the same, and the crack shape is similar. The results show that the complex stress state constitutive model parameters and the DIEM fracture model obtained in this paper can accurately predict the deformation and fracture failure behavior of the AM60B die-cast magnesium alloy sheet.

Transcriptome analysis revealed enrichment pathways and regulation of gene expression associated with somatic embryogenesis in Camellia sinensis.

The high frequency, stable somatic embryo system of tea has still not been established due to the limitations of its own characteristics and therefore severely restricts the genetic research and breeding process of tea plants. In this study, the transcriptome was used to illustrate the mechanisms of gene expression regulation in the somatic embryogenesis of tea plants. The number of DEGs for the (IS intermediate stage)_PS (preliminary stage), ES (embryoid stage)_IS and ES_PS stages were 109, 2848 and 1697, respectively. The enrichment analysis showed that carbohydrate metabolic processes were considerably enriched at the ES_IS stage and performed a key role in somatic embryogenesis, while enhanced light capture in photosystem I could provide the material basis for carbohydrates. The pathway analysis showed that the enriched pathways in IS_PS process were far less than those in ES_IS or ES_PS, and the photosynthesis and photosynthetic antenna protein pathway of DEGs in ES_IS or ES_PS stage were notably enriched and up-regulated. The key photosynthesis and photosynthesis antenna protein pathways and the Lhcb1 gene were discovered in tea plants somatic embryogenesis. These results were of great significance to clarify the mechanism of somatic embryogenesis and the breeding research of tea plants.

The improved entropy weighting model in water quality evaluation based on the compound function.

Entropy weight model (EWM) is widely used in water quality evaluation. In the conventional EWM, the weight is a monotone increasing function of the dispersion degree. However, this weighting principle often neglects the heavily polluted indicators. To solve this problem, an improved EWM is designed, in which the weight of the indicator is a compound function of its dispersion degree and pollution degree. In the clean domain, the weight increases with the dispersion degree, while in the polluted domain, the weight decreases with the dispersion degree. And for the same dispersion degree, the larger the pollution degree is, the higher the weight is, and vice versa. Subsequently, the improved EWM is applied to the water quality evaluation of Wucheng Wetland in Poyang Lake, China. Results are as follows: (i) For TP, CODMn, and NH3-N, their dispersion degrees are 0.001, 0.158, and 0.084; and their pollution degrees are 0.971, 0.277, and 0.281, respectively. (ii) According to the improved EWM, the weights of TP, CODMn, and NH3-N are 0.613, 0.197, and 0.190, respectively. (iii) The comprehensive water quality indices of estuary region, wetland region, and the central lake area are 32.5, 30.9, and 35.6, respectively, all of which belong to a "bad" grade. The water environment of Wucheng Wetland suffered serious damage of phosphorus, and the ecosystem faced a high threat. (iv) Compared with the conventional EWM, the improved EWM highlights the importance of polluted indicators, which makes the comprehensive evaluation results more rigorous and reasonable.

Effect of row-like puncture at sternocleidomastoid on peripheral facial palsy at recovery stage / 中国针灸

OBJECTIVE@#To observe the effect of conventional acupuncture combined with row-like puncture at sternocleidomastoid on peripheral facial palsy at recovery stage.@*METHODS@#A total of 60 patients with peripheral facial palsy at recovery stage were randomized into an observation group and a control group, 30 cases in each one. Acupuncture was applied at affected Cuanzhu (BL 2), Yangbai (GB 14), Sibai (ST 2), Quanliao (SI 18), Jiache (ST 6), Dicang (ST 4), Hegu (LI 4), Taichong (LR 3) and Zusanli (ST 36) in the control group. On the basis of the treatment in the control group, row-like puncture was applied at sternocleidomastoid (1 needle was punctured at muscle origin and insertion respectively, 3 to 4 needles were row-like punctured at the connection line of muscle origin and insertion). The treatment was given once a day, 5 times were as one course, with 2-day interval, totally 4 courses were required in the both groups. The house-brackmann (H-B) facial nerve function grade, facial nerve function rating system-dynamic view rating scale score and facial disability index (FDI) scale score [including scores of FDI physical function (FDIp) and FDI social life function (FDIs)] before and after treatment were observed, and the clinical efficacy was evaluated in the two groups.@*RESULTS@#After treatment, the H-B facial nerve function grades were improved compared before treatment in the both groups (@*CONCLUSION@#Compared with conventional acupuncture, combination therapy with row-like puncture at sternocleidomastoid can improve the therapeutic effect of peripheral facial palsy at recovery stage.

Hydrogen sulfide reduces regional myocardial ischemia injury through protection of mitochondrial function.

Hydrogen sulfide (H2S) is a signaling gasotransmitter, involved in various physiological and pathological processes. H2S-donating drugs have been tested to conjugate the beneficial effects of H2S with other pharmaceutical properties. It has been shown that the endogenous cystathionine-γ-lyase (CSE)/H2S pathway participates in myocardial ischemia injury in isolated hearts in rats. The present study aimed to investigate the cytoprotective action of H2S against acute myocardial ischemia injury in rats. Isolated rat hearts were perfused and subjected to ischemic conditions for 4 h. The hearts were assigned to five groups: Sham, model, infarct plus low-dose (5 µmol/l) NaHS, infarct plus middle-dose (10 µmol/l) NaHS and infarct plus high-dose (20 µmol/l) NaHS. The administration of NaHS enhanced the activity of CSE, increased the content of H2S and reduced infarct volumes following myocardial ischemia injury. Furthermore, the administration of NaHS attenuated the injury to organelles (including the mitochondria, nucleus and myofilaments) by reducing lactate dehydrogenase activity, decreasing the level of mitochondrial malondialdehyde and increasing the activities of superoxide dismutase and glutathione peroxidase in the ischemic myocardial mitochondria. These protective effects of H2S against myocardial ischemia injury appeared to be mediated by its antioxidant activities and the preservation of mitochondrial function.

[Effects of hydrogen sulfide on myocardial mitochondrial injury during acute myocardial ischemia in rats].

OBJECTIVE: To investigate the effect of hydrogen sulfide (H2S) on mitochondrial function in acute myocardial ischemia in rats. METHODS: Acute myocardial ischemia models were established by ligating the left anterior descending coronary artery (LADC) of rats. Fourty-eight male SD rats were randomly divided into 6 groups (n = 8): sham operation group, ischemia group, ischemia + sodium hydrosulfide (NaHS) low, middle and high dose groups and ischemia + DL-proparglycine(PPG) group. The ultrastructures of myocardial mitochondria were observed with electron microscope. The content of H2S in plasma and the activity of cystathionine-gamma-lyase (CSE) in myocardial tissue of rats were respectively detected. The swelling and activity of myocardial mitochondria were determined. The activities of ATPase, GSH-Px, SOD and the content of malondial-dehyde (MDA) in myocardial mitochondria of rats were also measured. RESULTS: Compared with those of the sham operation group, the content of H2S in plasma, the activity of CSE in myocardial tissue and the activity of myocardium mitochondria were significantly decreased. The activities of ATPase, SOD, GSH-Px in myocardial mitochondria were significantly decreased, The content of malondial dehyde(MDA) in myocardial mitochondria and the swelling of mitochondria were distinctly increased in the ischemia group (P < 0.01). Compared with those of the ischemia group, the content of H2S in plasma and the activity of CSE in myocardial tissue were increased, and the activities of mitochondria, ATPase, SOD, and GSH-Px in myocardial mitochondria were significantly increased in ischemia + NaHS low, middle and high-dose groups; the swelling of mitochondria and the content of MDA in myocardial mitochondria were significantly decreased in ischemia + NaHS middle and high-dose groups (P < 0.05 or P < 0.01). The administration of PPG could partially reduce the myocardial protection of hydrogen sulfide (P < 0.05 or P < 0.01). CONCLUSION: It could be concluded that the administration of hydrogen sulfide could enhance the activities of mitochondrial ATPase, SOD, GSH-Px, decrease the level of mitochondrial lipid peroxidation, and play a protective effect against acute myocardial ischemia.

Effects of hydrogen sulfide on myocardial mitochondrial injury during acute myocardial ischemia in rats / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To investigate the effect of hydrogen sulfide (H2S) on mitochondrial function in acute myocardial ischemia in rats.</p><p><b>METHODS</b>Acute myocardial ischemia models were established by ligating the left anterior descending coronary artery (LADC) of rats. Fourty-eight male SD rats were randomly divided into 6 groups (n = 8): sham operation group, ischemia group, ischemia + sodium hydrosulfide (NaHS) low, middle and high dose groups and ischemia + DL-proparglycine(PPG) group. The ultrastructures of myocardial mitochondria were observed with electron microscope. The content of H2S in plasma and the activity of cystathionine-gamma-lyase (CSE) in myocardial tissue of rats were respectively detected. The swelling and activity of myocardial mitochondria were determined. The activities of ATPase, GSH-Px, SOD and the content of malondial-dehyde (MDA) in myocardial mitochondria of rats were also measured.</p><p><b>RESULTS</b>Compared with those of the sham operation group, the content of H2S in plasma, the activity of CSE in myocardial tissue and the activity of myocardium mitochondria were significantly decreased. The activities of ATPase, SOD, GSH-Px in myocardial mitochondria were significantly decreased, The content of malondial dehyde(MDA) in myocardial mitochondria and the swelling of mitochondria were distinctly increased in the ischemia group (P < 0.01). Compared with those of the ischemia group, the content of H2S in plasma and the activity of CSE in myocardial tissue were increased, and the activities of mitochondria, ATPase, SOD, and GSH-Px in myocardial mitochondria were significantly increased in ischemia + NaHS low, middle and high-dose groups; the swelling of mitochondria and the content of MDA in myocardial mitochondria were significantly decreased in ischemia + NaHS middle and high-dose groups (P < 0.05 or P < 0.01). The administration of PPG could partially reduce the myocardial protection of hydrogen sulfide (P < 0.05 or P < 0.01).</p><p><b>CONCLUSION</b>It could be concluded that the administration of hydrogen sulfide could enhance the activities of mitochondrial ATPase, SOD, GSH-Px, decrease the level of mitochondrial lipid peroxidation, and play a protective effect against acute myocardial ischemia.</p>

Metabolism of fatty acids and lipid hydroperoxides in human body monitoring with Fourier transform Infrared Spectroscopy.

BACKGROUND: The metabolism of dietary fatty acids in human has been measured so far using human blood cells and stable-isotope labeled fatty acids, however, no direct data was available for human peripheral tissues and other major organs. To realize the role of dietary fatty acids in human health and diseases, it would be eager to develop convenient and suitable method to monitor fatty acid metabolism in human. RESULTS: We have developed the measurement system in situ for human lip surface lipids using the Fourier transform infrared spectroscopy (FTIR) - attenuated total reflection (ATR) detection system with special adaptor to monitor metabolic changes of lipids in human body. As human lip surface lipids may not be much affected by skin sebum constituents and may be affected directly by the lipid constituents of diet, we could detect changes of FTIR-ATR spectra, especially at 3005 to approximately 3015 cm(-1), of lip surface polyunsaturated fatty acids in a duration time-dependent manner after intake of the docosahexaenoic acid (DHA)-containing triglyceride diet. The ingested DHA appeared on the lip surface and was detected by FTIR-ATR directly and non-invasively. It was found that the metabolic rates of DHA for male volunteer subjects with age 60s were much lower than those with age 20s. Lipid hydroperoxides were found in lip lipids which were extracted from the lip surface using a mixture of ethanol/ethylpropionate/iso-octane solvents, and were the highest in the content just before noon. The changes of lipid hydroperoxides were detected also in situ with FTIR-ATR at 968 cm(-1). CONCLUSION: The measurements of lip surface lipids with FTIR-ATR technique may advance the investigation of human lipid metabolism in situ non-invasively.

Study on regulatory effect of Bushen Antai Recipe on levels of estrogen and progesterone in blastocyst implantation dysfunction mice / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To investigate the effect and explore the mechanism of Bushen Antai Recipe (BAR) on pregnancy rate and number of implantation site in blastocyst implantation dysfunction (BID) mice induced by indomethacin.</p><p><b>METHODS</b>Pregnant mice were divided into 3 groups randomly: the normal group, the model group and the BAR group. Tap water was given orally to the rats in the normal and model groups, and BAR to the rats in the BAR group from the first day of pregnancy for 5 or 8 days; on the 3rd and 4th day dissolvent was injected subcutaneously twice per day in the normal group, while indomethacin (4.33 mg/kg) was injected subcutaneously twice per day in the other two groups to establish implantation dysfunction model; serum estrogen (E) and progesterone (P4) levels were detected on the 5th and 8th day; the pregnancy rate and number of implanted site was observed and the receptors of E and P4 in endometrium of uterus were examined by immunohistochemistry on the 8th day.</p><p><b>RESULTS</b>The pregnancy rate and number of implanted site was 27.3% and 5.3 +/- 0.7 respectively in the model group, significantly lower than those in the normal group (90.9%, 13.3 +/- 2.8), and the BAR group (72.7%, 10.7 +/- 2.2, P < 0.05). Serum E level was higher in the BAR group than that in the model group on the 5th and 8th day, and even higher than that in the normal group on the 8th day; serum P4 level was lower in the model and BAR groups than that in the normal group on the 5th day (P < 0.01), but higher in the BAR group than that in the model group on the 8th day. Immunohistochemical observation showed that expressions of E and P4 receptor increased remarkably in the BAR group than those in the model group.</p><p><b>CONCLUSION</b>BAR increases the pregnancy rate and number of implanted site of indomethacrne induced BID mice through regulating E and P4 levels and enhancing the expressions of their receptors in the endometrium.</p>