3,911 research outputs found

    Oxytocin protects neurons from hypoxic-ischemic brain injury by enhancing inhibitory neurotransmission in neonatal rats

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    Purpose: To study the protective effect of oxytocin on hypoxic-ischemic brain neuron injury in neonatal rats, and the mechanism of action involved.Methods: Hippocampal slices from neonatal SD rats were cultured in oxygen/glucose-deprived (OGD) solution, leading to establishment of hypoxic-ischemic model of hippocampal slices in vitro. The slices were assigned to 3 groups: control (ACSF solution), model (OGD solution), and oxytocin (OGD solution + 1 μM oxytocin). The effect of oxytocin on vertebral neurons in hippocampal CA1 region of HIBD rats was determined using TOPRO-3 staining, while the effects of oxytocin on hypoxic depolarization (AD) and inhibitory postsynaptic currents (iPSCs) were measured by cell patch clamp technique.Results: The fluorescence intensity of vertebral lamina in hippocampal CA1 area of model group was significantly higher than that of control group, while the corresponding value for oxytocin group was significantly lower than that of model group (p < 0.05). The time lapse before occurrence of AD in hippocampal CA1 area was significantly longer in oxytocin group than in model group, while the time lapse before neuronal AD in oxytocin receptor antagonist group was lower than that in oxytocin group. The frequency and amplitude of iPSCs in oxytocin group were markedly higher than the corresponding control values.Conclusion: Oxytocin exerts protective effect against hypoxic-ischemic brain neuronal damage in neonatal rats by regulating the activation of oxytocin receptor and GABA receptor, and inhibiting nerve transmission. These findings may be of benefit in the development of a suitable therapy for HIBD

    HIF-1α Contributes to Hypoxia-induced Invasion and Metastasis of Esophageal Carcinoma via Inhibiting E-cadherin and Promoting MMP-2 Expression

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    Hypoxia-inducible factor-1α (HIF-1α) has been found to enhance tumor invasion and metastasis, but no study has reported its action in esophageal carcinoma. The goal of this study was to explore the probable mechanism of HIF-1α in the invasion and metastasis of esophageal carcinoma Eca109 cells in vitro and in vivo. mRNA and protein expression of HIF-1α, E-cadherin and matrix metalloproteinase-2 (MMP-2) under hypoxia were detected by RT-PCR and Western blotting. The effects of silencing HIF-1α on E-cadherin, MMP-2 mRNA and protein expression under hypoxia or normoxia were detected by RT-PCR and Western blotting, respectively. The invasive ability of Eca109 cells was tested using a transwell chambers. We established an Eca109-implanted tumor model and observed tumor growth and lymph node metastasis. The expression of HIF-1α, E-cadherin and MMP-2 in xenograft tumors was detected by Western blotting. After exposure to hypoxia, HIF-1α protein was up-regulated, both mRNA and protein levels of E-cadherin were down-regulated and MMP-2 was up-regulated, while HIF-1α mRNA showed no significant change. SiRNA could block HIF-1α effectively, increase E-cadherin expression and inhibit MMP-2 expression. The number of invading cells decreased after HIF-1α was silenced. Meanwhile, the tumor volume was much smaller, and the metastatic rate of lymph nodes and the positive rate were lower in vivo. Our observations suggest that HIF-1α inhibition might be an effective strategy to weaken invasion and metastasis in the esophageal carcinoma Eca109 cell line

    Simultaneous faults identification of rolling element bearings and gears by combining kurtogram and independent component analysis

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    A combination of kurtogram and independent component analysis (ICA) is proposed in this paper to identify the faults of rolling element bearings (REBs) and gears existing simultaneously in a gearbox. In the proposed scheme, multi-channel vibrations are picked up from the gearbox at first. Then, the fast kurtogram algorithm is employed to extract the envelopes of each vibration from different channels. Subsequently, the envelopes are separated by an ICA algorithm into independent envelope components according to different sources. Finally, the characteristic frequencies of both the faulty REB and the faulty gear can be exposed simultaneously in the envelope spectral plots. A simulation and an experimental test are introduced to show the effectiveness of the proposed method

    Environmental Factors and Male Infertility

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    A significant decrease in human fertility has been observed in the last 50 years. Approximately 15% of couples of reproductive age have fertility problems and about half of these cases are because of male factors. A growing body of evidence suggests that environmental factors play an important role in the causes of male infertility. Our environment is contaminated by natural and synthetic chemicals, which could interact with the endocrine system, resulting in the reduction of human fertility. Studies carried out in recent years have proven that endocrine-disrupting chemicals may disturb fertility of men. Improper lifestyle factors such as smoking, alcohol consumption, high temperature, radiation also have negative impact on male fertility. This chapter is an overview of recent developments about the importance of endocrine-disrupting chemicals and lifestyle factors’ effects on sperm counts and male fertility in human

    Quetiapine N-oxide–fumaric acid (2/1)

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    The title compound (systematic name: 2-{2-[4-(dibenzo[b,f][1,4]thia­zepin-11-yl)piperazin-1-yl 1-oxide]eth­oxy}ethanol–fumaric acid (2/1)), C21H25N3O3S·0.5C4H4O4, is one of the oxidation products of quetiapine hemifumaric acid. In the tricyclic fragment, the central thia­zepine ring displays a boat conformation and the benzene rings are inclined to each other at a dihedral angle of 72.0 (2)°. The piperazine ring adopts a chair conformation with its eth­oxy­ethanol side chain oriented equatorially. In addition to the main mol­ecule, the asymmetric unit contains one-half mol­ecule of fumaric acid, the complete mol­ecule being generated by inversion symmetry. In the crystal, O—H⋯O hydrogen bonds link the components into corrugated layers parallel to bc plane

    Chlorido(5-formyl-2-hydroxy­phenyl-κC 1)mercury(II)

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    In the planar (r.m.s. deviation = 0.027 Å) title compound, [Hg(C7H5O2)Cl], the HgII atom shows a typical linear coordination by a C atom of the benzene ring and a Cl atom. Inter­molecular O—H⋯O hydrogen bonds are present in the crystal structure, resulting in chains propagating along the b axis. The crystal studied was a non-merohedral twin, with a twin ratio of 0.802 (2):0.198 (2)
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