280 research outputs found

    Thermodynamic Cycle Analysis and Experimental Investigate on a Two-stage Vapor Injection Low Temperature Air Source Heat Pump with a Variable Displacement Ratio Rotary Compressor

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    Two-stage vapor injection compression cycle with flash tank was thermodynamically analyzed, the results showed that there existed the optimum theoretical displacement ratio of high stage to low stage corresponding to the maximum coefficient of performance(COP), the optimum displacement ratio and the volumetric heating capacity decreased with evaporation temperature decreasing. An optimum theoretical displacement ratio correlation for R290, R32 and R410A was given. A new type two-stage vapor injection low temperature air source heat pump (ASHP) was designed, which had a variable speed triple-cylinder rotary compressor with two cylinders in low stage and one cylinder in high stage. The experimental results of the new type ASHP showed that the heating capacity under 20℃/-20℃(inside room /outside room) could reach the rated heating capacity under 20℃/7℃, improving 96% compared to conventional one-stage ASHP, the heating capacity under 20℃/-30℃ could reach 80% of the rated one. COP of the new type ASHP could improve 5%~10% when the heating capacity was comparable to the conventional ASHP, and the heating capacity of the new type ASHP could improve 30%~50% when COP was comparable to the conventional ASHP

    Therapeutic effects of Saikosapoin D on bleomycininduced pulmonary fibrosis in mice via regulation of IL- 33/ST2 pathway

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    Purpose: To investigate the therapeutic effects of saikosapoin D (SSD) on bleomycin (BLM)-induced pulmonary fibrosis (PF) in mice and its probable mechanisms.Methods: PF mice were prepared by intraperitoneal (i.p.) injection of BLM (5 mg/kg). Twenty-four hours later, 72 mice in SSD group were administered SSD (1.8 mg/kg, ip). After 3, 7, 14 and 28 days of injection, the mice were sacrificed. Blood samples and lung tissues were collected from 6 mice in each group. The lung tissues were subjected to histological examination. In addition, expressions of MyD88, TRAF6, IL-33 and ST2 in lung tissue were determined by western blotting assay. Serum levels of hydroxyproline (HYP), interleukin (IL)-4, IL-13 and interferon (IFN)-γ were measured by enzyme-linked immunosorbent assay (ELISA).Results: Pathological results showed that SSD treatment alleviated alveolitis and lung fibrosis (p < 0.05) in lung tissues of PF mice at 14 and 28 days post-BLM injection. HYP and IL-13 levels of mice in SSD group were significantly lower than that in BLM group at days 14 and 28 post-BLM injection (p < 0.05). Levels of IL-4 and IFN-γ were significantly lower when compared with values in BLM group on day 28 (p < 0.05). Western blotting results revealed that expressions of MyD88, TRAF6, IL-33 and ST2 proteins were significantly decreased by SSD treatment (p < 0.05).Conclusion: SSD exerts therapeutic effects on BLM-induced experimental PF in mice via regulation ofIL-33/ST2 pathway.Keywords: Saikosapoin D, Idiopathic pulmonary fibrosis, Myeloid differentiation factor, Hydroxyproline, Interleukin, Interferon, IL-33/ST2 pathwa

    Imprinting and Promoter Usage of Insulin-Like Growth Factor II in Twin Discordant Placenta

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    Case reports from infant twins suggest that abnormal genomic imprinting may be one of the important causes of twin discordance, but it is unknown whether abnormal genomic imprinting occurs in the placenta. Therefore, we sought to determine the relationship between the imprinting of insulin-like growth factor II (IGF-II) in placenta and twin discordance. We analyzed the imprinting and promoter usage of IGF-II in placenta of normal twins (T0 group), weight discordance (T1 group), and phenotype discordance (T2 group). We found the incidence of loss of imprinting (LOI) for IGF-II was higher in the T2 group than that in the T0 and T1 groups, while there was no difference between T0 and T1 groups. The transcripts of promoter 3 were lower in the T2 group than in the T0 and T1 groups, and lower in the twin placenta with LOI than in those with normal imprinting. Our findings indicate that the promoter 3 specific LOI of the IGF-II gene may be closely related with phenotype discordance, not weight discordance

    Longan seed and mangosteen skin based activated carbons for the removal of Pb(II) ions and rhodamine-B dye from aqueous solutions

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    Agricultural biomass wastes of longan seed and mangosteen skin were collected as precursors to prepare activated carbons (LS-AC-5 and MS-AC-5, respectively) through carbonization at medium temperature and KOH activation at high temperature. Their pore structures, structural properties and surface morphologies were characterized by X-ray diffractometer, Brunauer–Emmett–Teller surface measurement system, and scanning electron microscopy, respectively. Effects of contact time and pH on adsorption performances of samples were investigated by removal of Pb(II) ions and Rhodamine-b from aqueous solutions. Experimental adsorption isotherms of Rhodamine-b and Pb(II) ions on LS-AC-5 and MS-AC-5 fitted well with the Langmuir model. Results further showed that MS-AC-5 exhibited a larger surface area of 2960.56 m2/g and larger portions of micropores and mesopores (pore volume of 1.77 cm3/g) than LS-AC-5 (surface area: 2728.98 m2/g; pore volume: 1.39 cm3/g). Maximum monolayer adsorption capabilities of 1265.82 and 117.65 mg/g for Rhodamine-b and Pb(II) ions on MS-AC-5 were higher than those on LS-AC-5 (1000.20 and 107.53 mg/g), respectively

    Endothelial Atg7 Deficiency Ameliorates Acute Cerebral Injury Induced by Ischemia/Reperfusion

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    Ischemic strokes often result in cerebral injury due to ischemia/reperfusion (I/R). Although the local inflammatory responses are known to play a primary role in the brain I/R injury, the underlying mechanism remains unclear. In the current study, we investigated the effect of brain endothelial Atg7 (autophagy related 7) depletion in the acute brain injury induced by ischemia and reperfusion. Endothelial knockout of Atg7 in mice (Atg7 eKO) was found to significantly attenuate both the infarct volume and the neurological defects induced by I/R when compared to the controls. In fact, brain inflammatory responses induced by I/R were alleviated by the Atg7 eKO. Furthermore, an increased expression of pro-inflammatory cytokines, including IL-1β, IL-6, IL-8, and TNF-α, was observed in brain endothelial cells in response to oxygen/glucose depletion/reoxygenation, which was decreased by the shRNA-mediated Atg7 knockdown. Interestingly, Atg7 knockdown reduced IKKβ phosphorylation, leading to NF-κB deactivation and downregulation of the pro-inflammatory cytokines mRNA levels. Further, Atg7 transcriptional regulation function is independent of its role in autophagy. Taken together, our results demonstrated that brain endothelial Atg7 contributes to brain damage during I/R by modulating the expression of pro-inflammatory cytokines. Depletion of Atg7 in brain endothelium has a neuroprotective effect against the ischemia/reperfusion-induced acute cerebral injury during stroke

    Progress on fabrication, modification and applications of titania nanotube Arrays

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    Titania nanotube arrays as a novel nano-material has unique highly ordered array structure, good mechanical and chemical stability, as well as excellent corrosion resistance. It has been fabricated by electrochemical anodization of pure Ti sheet in electrolytes containing small amounts of fluoric ions. This paper reviews the new research achievements of TiO2 nanotube arrays on the preparation processes, forming mechanism, modification and the applications in the photocatalytic degradation of pollutants, solar cells, gas sensor materials, photolysis water. The existing problems and further prospects in this field are also discussed

    Fabrication of highly ordered titanium dioxide nanotube array and investigation of its photocatalytic activity

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    A highly ordered titanium dioxide (TiO2) nanotube array film on titanium substrate was fabricated by using an electrochemical anodic oxidation method, and some preparation parameters of the TiO2 nanotube arrays were investigated as well. The SEM and XRD experiments were performed to characterize the morphology and crystalline phase of the TiO2 nanotube arrays. It was found that the morphology of the TiO2 nanotube arrays was greatly associated with the anodization voltage. The photocatalytic activity of the TiO2 nanotube array film was evaluated by the decolorization of methyl orange under the illumination of a high-pressure mercury lamp. The results showed that the TiO2 nanotube arrays prepared at 20 V and annealed at 500 degrees C exhibited the best photocatalytic activity to the degradation of methyl orange. And the photocatalytic activity of the TiO2 nanotube array film was much higher than that of the regular TiO2 nanoparticle film

    Multiple organ infection and the pathogenesis of SARS

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    After >8,000 infections and >700 deaths worldwide, the pathogenesis of the new infectious disease, severe acute respiratory syndrome (SARS), remains poorly understood. We investigated 18 autopsies of patients who had suspected SARS; 8 cases were confirmed as SARS. We evaluated white blood cells from 22 confirmed SARS patients at various stages of the disease. T lymphocyte counts in 65 confirmed and 35 misdiagnosed SARS cases also were analyzed retrospectively. SARS viral particles and genomic sequence were detected in a large number of circulating lymphocytes, monocytes, and lymphoid tissues, as well as in the epithelial cells of the respiratory tract, the mucosa of the intestine, the epithelium of the renal distal tubules, the neurons of the brain, and macrophages in different organs. SARS virus seemed to be capable of infecting multiple cell types in several organs; immune cells and pulmonary epithelium were identified as the main sites of injury. A comprehensive theory of pathogenesis is proposed for SARS with immune and lung damage as key features

    Unraveling the Novel Protective Effect of Patchouli Alcohol Against Helicobacter pylori-Induced Gastritis: Insights Into the Molecular Mechanism in vitro and in vivo

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    Patchouli alcohol (PA), a natural tricyclic sesquiterpene extracted from Pogostemon cablin (Blanco) Benth. (Labiatae), has been found to exhibit anti-Helicobacter pylori and anti-inflammatory properties. In this study, we investigated the protective effect of PA against H. pylori-induced gastritis in vitro and in vivo, and determined the underlying mechanism. In the in vivo experiment, a C57BL/6 mouse model of gastritis was established using H. pylori SS1, and treatments with standard triple therapy or 5, 10, and 20 mg/kg PA were performed for 2 weeks. Results indicated that PA effectively attenuated oxidative stress by decreasing contents of intracellular reactive oxygen species (ROS) and malonyldialdehyde (MDA), and increasing levels of non-protein sulfhydryl (NP-SH), catalase and glutathione (GSH)/glutathione disulphide (GSSG). Additionally, treatment with PA significantly attenuated the secretions of interleukin 1 beta (IL-1β), keratinocyte chemoattractant and interleukin 6 (IL-6). PA (20 mg/kg) significantly protected the gastric mucosa from H. pylori-induced damage. In the in vitro experiment, GES-1 cells were cocultured with H. pylori NCTC11637 at MOI = 100:1 and treated with different doses of PA (5, 10, and 20 μg/ml). Results indicated that PA not only significantly increased the cell viability and decreased cellular lactate dehydrogenase (LDH) leakage, but also markedly elevated the mitochondrial membrane potential and remarkably attenuated GES-1 cellular apoptosis, thereby protecting gastric epithelial cells against injuries caused by H. pylori. PA also inhibited the secretions of pro-inflammatory factors, such as monocyte chemotactic protein 1 (MCP-1), tumor necrosis factor-α (TNF-α) and IL-6. Furthermore, after PA treatment, the combination of NACHT, LRR, and PYD domains-containing protein 3 (NLRP3) and cysteine-aspartic proteases 1 (CASPASE-1), the expression levels of NLRP3 inflammasome-related proteins, such as thioredoxin-interacting protein (TXNIP), pro-CASPASE-1, cle-CASPASE-1, and NLRP3 and genes (NLRP3 and CASPASE1) were significantly decreased as compared to the model group. In conclusion, treatment with PA for 2 weeks exhibited highly efficient protective effect against H. pylori-induced gastritis and related damages. The underlying mechanism might involve antioxidant activity, inhibition of pro-inflammatory factor and regulation of NLRP3 inflammasome function. PA exerted anti-H. pylori and anti-gastritis effects and thus had the potential to be a promising candidate for treatment of H. pylori-related diseases

    Neutrophil Extracellular Traps Promote Inflammatory Responses in Psoriasis via Activating Epidermal TLR4/IL-36R Crosstalk

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    Epidermal infiltration of neutrophils is a hallmark of psoriasis, where their activation leads to release of neutrophil extracellular traps (NETs). The contribution of NETs to psoriasis pathogenesis has been unclear, but here we demonstrate that NETs drive inflammatory responses in skin through activation of epidermal TLR4/IL-36R crosstalk. This activation is dependent upon NETs formation and integrity, as targeting NETs with DNase I or CI-amidine in vivo improves disease in the imiquimod (IMQ)-induced psoriasis-like mouse model, decreasing IL-17A, lipocalin2 (LCN2), and IL-36G expression. Proinflammatory activity of NETs, and LCN2 induction, is dependent upon activation of TLR4/IL-36R crosstalk and MyD88/nuclear factor-kappa B (NF-κB) down-stream signaling, but independent of TLR7 or TLR9. Notably, both TLR4 inhibition and LCN2 neutralization alleviate psoriasis-like inflammation and NETs formation in both the IMQ model and K14-VEGF transgenic mice. In summary, these results outline the mechanisms for the proinflammatory activity of NETs in skin and identify NETs/TLR4 as novel therapeutic targets in psoriasis
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