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In the construction of tunnels under existing stations, it is necessary to control their settlement. When there is a pile foundation in the existing station, the pile cutting has a significant impact on the settlement of the existing station. To determine the influence of existing piles on the settlement of subway stations, a reasonable pile-cutting time is proposed. Based on the Chengdu Metro Line 9 underpassing the existing Line 1 hatchery station, the settlement law of the tunnel underpassing the existing Line 1 station is analysed via a numerical simulation. Furthermore, the deformation and stress characteristics of the existing piles, pipe roofs, and tunnel linings and the supporting effect on the existing station are discussed. It is concluded that the cutting of existing piles causes a change in the tunnel bearing system, thus resulting in a certain deformation of the station. The influence of different pile cutting times on the settlement of the existing station is then analysed, and it is clarified that the tunnel support stiffness is significantly enhanced after the construction of the secondary lining. At this time, the settlement of the existing pile station is significantly reduced. Finally, through a field investigation, the effect of surface grouting, pipe shed, and multilayer lining on the settlement control of the existing station while the existing pile foundation exists is determined. This research can provide a reference for the settlement control and foundation underpinning of existing stations at ultra-small distances in underground excavation tunnels.
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To solve the problem of easy delamination of the interface of Al/CFRP/Al laminate (CFRP, carbon fiber composite; Al, aluminum), a method of constructing high strength and toughness at the interface is proposed. The effects of adding resin and carbon nanotubes at the interface on the shear, flexural strength and impact resistance of Al/CFRP/Al laminates are studied. Experimental results show that gullies and micropores can be formed on the surface of aluminum after pretreatment, and the contact area between aluminum and matrix can be increased. After resin is added to the Al/CFRP interface, the shear strength between layers and the bending strength and impact resistance of laminates are improved. Mixing carbon nanotubes into the added resin will further improve the mechanical properties of laminates. On the basis of strengthening and toughening the Al/CFRP interface, the carbon nanotubes added between the CFRP layers can strengthen and toughen the resin at the interface, which enhances the bending strength and impact resistance of the laminates. When the resin between the layers breaks, the carbon nanotubes will be pulled off and pulled out to resist the damage of the resin, and the carbon nanotubes at the end of the crack can hinder the propagation of the cracks.
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BACKGROUND: Endothelial dysfunction appears early in the development of cardiovascular disease and is associated with type 2 diabetes. We, therefore, tested the hypothesis that endothelial dysfunction is already present in healthy Chinese adolescent participants at risk of type 2 diabetes and associates with physical activity. METHODS: We investigated the flow-mediated dilation in 65 first-degree relatives (normal tension, normal glucose tolerance) and 62 age-, sex- and BMI-matched controls without a family history of type 2 diabetes by ultrasound. Physical activity level was assessed using the Global Physical Activity Questionaire and type 2 diabetes family history through self-reporting. The association between physical activity and flow-mediated dilation was evaluated by Pearson correlations and multiple regressions in adolescents with or without a family history of type 2 diabetes. RESULTS: Female adolescents display better flow-mediated dilation than males. Adolescents with a family history of type 2 diabetes had significantly impaired flow-mediated dilation than healthy controls. Among the parameter detection in the blood, the flow-mediated dilation is only positively associated with high-density lipoprotein cholesterol level, but not others. Interestingly, flow-mediated dilation is positively corrected with physical activity scores in both the male and female adolescents, while slightly impaired but not significant in adolescents with a family history of type 2 diabetes. CONCLUSION: Studies in adolescents are important to understand the early pathogenesis of type 2 diabetes. Findings of this investigation suggest that family history of type 2 diabetes may play a role in regulating the vascular function in Chinese adolescents. Given the impaired flow-mediated dilation in individuals with family history and the effects of physical activity in improved flow-mediated dilation, people with a family history of type 2 diabetes may need higher physical activity levels to attenuate their susceptibility to impaired flow-mediated dilation.
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Diabetes Mellitus Tipo 2 , Adolescente , Artéria Braquial , China , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/genética , Dilatação , Endotélio Vascular , Feminino , Humanos , Masculino , Vasodilatação/fisiologiaRESUMO
Metal composite interface properties significantly affect the integrity, bonding properties, and interface structure of Fibre Metal Laminates (FMLs). Interfacial bonding strength's effect on Carbon Fibre-Reinforced Aluminium Laminate (CARALL) mechanical behaviours was investigated via three-point bending and low-velocity impact tests. AA6061 sheets were subjected to surface pretreatments under three conditions (anodizing and A-187 and A-1387 surface modifications) to obtain different interfacial bonding strengths. The bonding interfaces of CARALL were analysed using scanning electron microscopy, energy dispersive spectroscopy and X-ray photoelectron spectroscopy. Interfacial bonding strength between aluminium alloy and epoxy resin was determined by the tension-shear test. CARALL's energy absorption capacity and failure mode were analysed after low-velocity impact and three-point bending under different aluminium alloy volume contents and surface pretreatments. Upon modification of metal surfaces, the interfacial bonding strength increased, and the highest was obtained by silane coupling agent A-1387. Improved strength maintained FML's integrity under quasi-static and dynamic loadings. A-1387 improved the bonding ability of aluminium alloy and Carbon Fibre-Reinforced Plastics (CFRP). The composite interface strongly resisted crack propagation because of its functional group characteristics. When the volume content of aluminium alloy was less and greater than that of CFRP, the energy absorption capacity of CARALL weakened and strengthened, respectively, with increasing interfacial bonding strength.
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Purpose: Various studies have identified miR-202 critically participated in the development of different cancers. However, the potential mechanisms underlying the carcinogenesis of pancreatic cancer (PC) still remains elusive. Methods: In the study, cell proliferation assay, colony formation assay, EdU incorporation assay, Luciferase reporter assay, lactate production, glucose consumption assay, real-time PCR and western blot were used to investigate the mechanism of hexokinase 2 (HK2) regulated by miR-202 in pancreatic cancer in vitro and in vivo. Results: Here we found that miR-202 was decreased in the PC tissues, and its low expression was correlated with a poor prognosis of PC patients. Overexpression of miR-202 in PC cells reduced cell proliferation and tumorigenesis by impairing glycolysis, while downregulation of miR-202 promoted the cells proliferative capacity. Mechanically, we demonstrated that HK2, an enzyme that catalyzes the irreversible rate-limiting step of glycolysis, as the direct target of miR-202. Overexpression of miR-202 suppressed both the mRNA and protein levels of HK2, whereas re-introduction of HK2 abrogated miR-202-mediated glycolytic inhibition. In addition, the expression of miR-202 was negatively associated with HK2 level in a cohort of PC tissues. Conclusion: Our findings validate the mechanism that miR-202 reprograms the metabolic process to promote PC progression, thus providing potential prognostic predictors for PC patients.
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Hepatocellular carcinoma (HCC) is the second leading cause of cancer mortality worldwide, which is mainly due to relapse and metastasis. Synaptophysin-like 1 (SYPL1), a member of SYP family proteins, exerts complicated functions, which prompted us to wonder whether SYPL1 contributed to HCC progress. Herein, we performed integrative experiments of quantitative real-time polymerase chain reaction (qRT-PCR), western blot analysis and immunohistochemistry (IHC), and found that SYPL1 overexpression in HCC tissues was closely correlated with several malignant clinicopathologic features of HCC. The results from IHC in serial sections of HCC tissues further indicated that SYPL1 expression was associated with epithelial-mesenchymal transition (EMT) biomarkers of HCC cells. Additionally, Kaplan-Meier survival analysis showed that SYPL1 overexpression was significantly associated with reduced overall survival (OS) (p<0.001) and disease-free survival (DFS) (p=0.002). Furthermore, univariate and multivariate Cox proportional hazards analysis identified SYPL1 as an independent prognostic factor for OS [hazard ratio (HR), 2.443, 95% confidence interval (CI), 1.429-4.177, p=0.001] and DFS (HR, 1.680, 95% CI=1.012-2.788, p=0.045) of HCC patients. Collectively, SYPL1 overexpression predicts poor prognosis of HCC and may associate with EMT of HCC cells. Therefore, SYPL1 could serve as a future novel biomarker and potential therapy target for HCC.
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Carcinoma Hepatocelular/genética , Transição Epitelial-Mesenquimal/genética , Neoplasias Hepáticas/genética , Sinaptofisina/genética , Biomarcadores Tumorais/genética , Carcinoma Hepatocelular/patologia , Intervalo Livre de Doença , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Estimativa de Kaplan-Meier , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/patologia , Estadiamento de Neoplasias/métodos , Prognóstico , Modelos de Riscos Proporcionais , Regulação para Cima/genéticaRESUMO
BACKGROUND AND AIM: Postoperative infection is not uncommon after hepatectomy. This study assessed the effectiveness of preoperative antibiotic prophylaxis in elective hepatectomy in a randomized clinical trial setting. METHODS: A total of 120 patients who were scheduled to undergo elective hepatectomy were equally randomized to receive either intravenous cefuroxime 1.5 g (group A) or placebo (group B) within 30 min prior to skin incision. RESULTS: Overall, postoperative infection occurred in 26 (21.6 %) of the 120 patients. There was no statistically significant difference between groups A and B in the incidence of overall infection (23.3 vs. 20.0 %, P = 0.658), surgical site infection (13.3 vs. 15 %, P = 0.793), and remote site infection (13.3 vs. 11.7 %, P = 0.783). CONCLUSION: The use of preoperative antibiotic prophylaxis as a routine practice in patients undergoing elective hepatectomy is unnecessary because it does not reduce the risk of postoperative infectious complications.
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Antibacterianos/farmacologia , Hepatectomia/efeitos adversos , Complicações Pós-Operatórias/prevenção & controle , Idoso , Antibacterianos/administração & dosagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de RiscoRESUMO
BACKGROUND/OBJECTIVE: Postoperative nausea and vomiting (PONV) is one of the most common and distressing adverse events after laparoscopic cholecystectomy (LC). A meta-analysis of randomized clinical trials (RCTs) was performed to determine the efficacy and safety of dexamethasone combined with other antiemetic in the prevention of PONV in patients undergoing LC. METHODS: A systematic literature search was conducted to identify all relevant RCTs. The primary outcome was PONV in the early period (0-3 hours, 0-4 hours, or 0-6 hours), late period (>6 hours), and the overall period (0-24 hours). RESULTS: Nine RCTs with a total of 1089 patients were included in the analysis. Pooled analysis showed that dexamethasone combined with other antiemetics provided significantly better prophylaxis than single antiemetics in the early period [odds ratio (OR): 0.34; 95% confidence interval (CI): 0.21-0.55; p < 0.001], late period (OR: 0.35; 95% CI: 0.22-0.57; p < 0.001), and the overall period (OR: 0.36; 95% CI: 0.27-0.49; p < 0.001). Correspondingly, rescue antiemetic usage was significantly less in the combination therapy group (OR: 0.22; 95% CI: 0.12-0.41; p < 0.001). The most frequently reported adverse events were headache, dizziness, and itching. The incidence of adverse events did not differ between the two groups. CONCLUSION: Dexamethasone combined with other antiemetics was significantly better than single antiemetics for prophylaxis of PONV in patients undergoing LC, without apparent side effects.
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Antieméticos/administração & dosagem , Colecistectomia Laparoscópica , Dexametasona/administração & dosagem , Náusea e Vômito Pós-Operatórios/prevenção & controle , Antieméticos/efeitos adversos , Dexametasona/efeitos adversos , Quimioterapia Combinada , Humanos , Período Pós-Operatório , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do TratamentoRESUMO
BACKGROUND: The aim of this study was to evaluate the safety and efficacy of distal pancreatectomy with en bloc celiac axis resection (DP-CAR) for pancreatic body-tail cancer. MATERIAL AND METHODS: The medical records of 12 patients who underwent DP-CAR for pancreatic body-tail cancer were retrospectively studied, together with a literature review of studies including at least 3 cases of DP-CAR. RESULTS: There were no deaths among our 12 cases. Postoperative morbidity developed in 9 cases and was successfully managed by non-surgical treatment. No patients developed ischemic complications. Median overall survival was 10 months. A total of 19 studies involving 203 patients who underwent DP-CAR were included in the literature review. The overall morbidity and mortality rates were 50.2% and 3.0%, respectively. The overall median survival after surgery ranged from 9.3 to 26 months. CONCLUSIONS: DP-CAR is a safe and effective treatment for patients with locally advanced pancreatic body-tail cancer.
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Artéria Celíaca/cirurgia , Pancreatectomia/métodos , Neoplasias Pancreáticas/cirurgia , China , Humanos , Neoplasias Pancreáticas/mortalidade , Estudos Retrospectivos , Taxa de SobrevidaRESUMO
Naked2 (NKD2) is a member of the Naked family and negatively regulates canonical Wnt signaling. NKD2 may play a role in embryo development and tumor formation by affecting Wnt signaling. In the present study, we describe the establishment of a monoclonal antibody against NKD2 (anti-NKD2 MAb) through the hybridoma method. The purified anti-NKD2 MAb measured a titer of 2.56 × 10(5) against NKD2 by indirect ELISA. Western blot analysis, immunoprecipitation, and confocal microscope showed that the anti-NKD2 MAb can specifically combine NKD2 protein in SW480 and LOVO cells. Competitive inhibition assays of Western blot and indirect ELISA showed that the anti-NKD2 MAb can be blocked with NKD2(1-217) protein. The anti-NKD2 MAb would be helpful for further studies on the structure activity relationship, protein detecting, and cell-signaling pathway of NKD2.
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Anticorpos Monoclonais/imunologia , Proteínas de Transporte/imunologia , Neoplasias Colorretais/imunologia , Hibridomas/imunologia , Proteínas Adaptadoras de Transdução de Sinal , Animais , Anticorpos Monoclonais/biossíntese , Anticorpos Monoclonais/isolamento & purificação , Formação de Anticorpos , Especificidade de Anticorpos , Western Blotting , Proteínas de Ligação ao Cálcio , Proteínas de Transporte/isolamento & purificação , Proteínas de Transporte/metabolismo , Neoplasias Colorretais/metabolismo , Ensaio de Imunoadsorção Enzimática , Feminino , Citometria de Fluxo , Humanos , Imunização , Imunoprecipitação , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Confocal , Proteínas Recombinantes , Células Tumorais CultivadasRESUMO
BACKGROUND: Obese patients are generally believed to be at increased risk for surgery compared with those who are not obese. A meta-analysis was performed to assess the outcomes of laparoscopic colorectal surgery in obese and nonobese patients. METHODS: A systematic literature search from inception to June 2011 was performed. Pooled odds ratios (OR) and weighted mean differences (WMD) with 95% confidence intervals (95% CI) were calculated using the fixed effects model or random effects model. RESULTS: Eight observational studies identified and matched the selection criteria. Conversion rates (OR: 2.31, 95% CI: 1.74-3.08), operating time (WMD: 15.33, 95% CI: 1.81-28.85), and postoperative morbidity (OR: 2.11; 95% CI: 1.3-3.42) were all significantly increased in the obese group. Length of hospital stay and mortality were similar in both groups. For patients with cancer, there was no difference between groups for the number of harvested nodes and length of specimen. CONCLUSIONS: Obesity is associated with increased conversion rate, operating time, and postoperative morbidity of laparoscopic colorectal surgery but does not affect surgical safety or oncological security.