203 research outputs found

    Research on stress intensity factors of elliptical hole in infinite body

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    This paper deals with such a kind of surface crack problem with an approximately same depth by using the hybrid displacement discontinuity method (a boundary element method) proposed recently by the author. Based on surface rectangular crack in infinite solid in tension and a hybrid displacement discontinuity method, a numerical approach is presented. By changing geometry parameters of elliptical hole, the effect of geometry parameters of the elliptical hole in infinite body in tension on the SIFs is revealed in detail. It is illustrated that the boundary element method is simple, yet accurate for calculating the SIFs of complex crack problems in finite plate

    Experimental and theoretical investigations of Cs+ adsorption on crown ethers modified magnetic adsorbent

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    This work was financially supported by the NSFC (No: U1607105 and No: 51574286). The Scientific and Technological Funding in Qinghai Province (No: 2018-GX-101, No: 2018-ZJ-722 and No: 2019-HZ-808). “Light of West China” Program and Youth Innovation Promotion Association of CAS (No: 2015141 and 2016377).Carboxyl Fe3O4 nanoparticles (Fe3O4@R-COOH) modified with 18-Crown-6 ether functional groups have been prepared via an amidation reaction and used as bifunctional adsorbent for Cs+. The adsorbent has a superparamagnetic property, allowing an easy recycling, and a high capacity of Cs+ adsorption on the crown ether. The adsorption isotherms and kinetic behaviors agree well with the Langmuir and the pseudo-second-order models. The material exhibits a high selectivity for Cs+ in the solution with co-existing cations (NH4+, Rb+, K+, Na+ and Li+). A theoretical calculation according to density functional theory (DFT) is used to estimate the structure of Cs+ adsorption on crown ether, demonstrating an exothermic process and showing a good agreement with the experimental observations. The adsorption behavior is affected not only by the size of macrocyclic crown ethers, but also by the chelating symmetry and the binding energy. The newly developed adsorbent has a potential application for removing cesium out of wastewater and salt lakes.PostprintPeer reviewe

    Chronic Alcohol Treatment-Induced GABA-Aα5 Histone H3K4 Trimethylation Upregulation Leads to Increased GABA-Aα5 Expression and Susceptibility to Alcohol Addiction in the Offspring of Wistar Rats

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    Gamma-aminobutyric acid (GABA)-Aα5 is considered to be associated with alcohol-induced memory deficits. However, whether it participates in the formation of alcohol addiction or in the regulation of its susceptibility is unknown. Here, we used a chronic alcohol treatment model to obtain alcohol-addicted Wistar rats. Long-term alcoholism increased the expression of prefrontal cortex GABA-Aα5 by inducing its histone H3K4 trimethylation, and these changes could be hereditary and lead to increased vulnerability to alcohol addiction in offspring. This study indicates the risk of long-term alcoholism in future generations, emphasizes the importance of GABA-Aα5 in the formation of alcohol addiction and the regulation of its susceptibility, and provides new evidence regarding the mechanisms underlying alcohol addiction

    Tris(ethylenediamine)cobalt(II) bis(tetra­hydroxypentaborate) dihydrate

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    The novel pentaborate with a transition-metal complex as counter-cation and with water of crystallization, tris(ethylenediamine)cobalt(II) bis[4,4′,6,6′-tetrahydroxy-2,2′-spirobi(cyclotriboroxane)(1−)] dihydrate, [Co(C2H8N2)3][B5O6(OH)4]2·2H2O, forms a three-dimensional supra­molecular framework through O—H⋯O hydrogen bonding among the [B5O6(OH)4]− anions with large channels along the a axis in which the templating [Co(en)3]2+ cations (en = ethylenediamine) and water mol­ecules are located. The crystal packing is consolidated by additional O—H⋯O and N—H⋯O hydrogen bonds

    Second-Line Combination Chemotherapy with Docetaxel and Nedaplatin for Cisplatin-Pretreated Refractory Metastatic/Recurrent Esophageal Squamous Cell Carcinoma

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    Background:There is an urgent need for an effective second-line chemotherapy regimen after failure of the standard cisplatin and 5-fluorouracil therapy.Patients and Methods:This study investigated the efficacy and toxicity of the combination of docetaxel (30 mg/m2) during a 1-hour infusion, followed by nedaplatin (50 mg/m2) during a 2-hour infusion (both drugs were administered on day 1 as an outpatient regimen and repeated every 2 weeks) as second-line chemotherapy for patients with cisplatin-pretreated refractory metastatic/recurrent esophageal squamous cell carcinoma after surgery.Results:Forty-six of the 48 patients (95.8%) were assessable for response. Partial response was confirmed in 13 of 48 cases yielding a response rate of 27.1% (95% confidence interval [CI], 14.5–39.7%). The median overall time to progression and overall survival was 3.1 months (95% CI, 2.3–3.9 months) and 5.9 months (95% CI, 3.9–7.8 months), respectively. The estimate of overall survival at 12 months was 16.7% (95% CI, 6.1–27.2%). Grade 3 anemia leucopenia, grade 4 anemia leucopenia and neutropenia were detected in only 4 (8.7%), 8 (17.4%), and 9 patients (19.6%), respectively.Conclusions:The combination chemotherapy of docetaxel and nedaplatin in the outpatient setting is well tolerated and useful as second-line chemotherapy for cisplatin-pretreated refractory metastatic/recurrent esophageal squamous cell carcinoma

    Hyaluronic acid ameliorates intervertebral disc degeneration via promoting mitophagy activation

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    Activation of mitophagy was considered to be a potential therapeutic strategy for intervertebral disc degeneration (IDD). There was evidence suggesting that hyaluronic acid (HA) can protect mitochondria from oxidative stress in chondrocytes, but its protective effects and mechanism in nucleus pulposus cells (NPCs) remain unclear. This study aimed to confirm the effect of HA promoting mitophagy and protecting mitochondria function in NPCs, and explore its underlying mechanism. NPCs were treated with high molecular weight HA, tert-butyl hydroperoxide (TBHP) and Cyclosporin A (CsA). Mitophagy, mitochondrial function, apoptosis, senescence and extracellular matrix (ECM) degradation were measured. Then, NPCs were transfected with C1QBP siRNA, mitophagy and mitochondrial function were tested. The therapeutic effects of HA on IDD by promoting mitophagy were assessed in bovine intervertebral disc organ culture model. The results showed that TBHP induced oxidative stress, mitochondrial dysfunction, NPCs apoptosis, senescence and ECM degradation. Treated by HA, mitophagy was activated, concomitantly, mitochondrial dysfunction, apoptosis, senescence and ECM degradation were ameliorated. Mitophagy inhibition by CsA partially eliminated the protective effects of HA against oxidative stress. After transfected with C1QBP siRNA to reduce the expression of C1QBP in NPCs, the effect of HA promoting mitophagy was inhibited and the protective effect of HA against oxidative stress was weaken. Additionally, HA alleviated NPCs apoptosis and ECM degradation in bovine intervertebral disc organ culture model. These findings suggest that HA can protect mitochondrial function through activation of mitophagy in NPCs and ameliorate IDD. Furthermore, C1QBP is involved in HA promoting mitophagy and protecting NPCs from oxidative stress. Taken together, our results provide substantial evidence for the clinical applications of HA in the prevention and treatment of IDD
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