•Experimental test results on the mechanical behavior of Recycled Aggregate Concrete (RAC) under triaxial compression are reviewed and discussed.•The static and cyclic behavior of FRP-confined RAC ...columns is discussed.•Strength prediction models of RAC under triaxial compression and FRP-confined RAC columns are proposed.
This paper presents a review of experimental tests performed for the characterization of the mechanical behavior of FRP-concrete members realized employing Recycled Aggregate Concrete (RAC). First, with the aim to define confinement effects on RAC, the mechanical behaviors of RAC under triaxial compression is discussed, highlighting the governing variables and their influence on the mechanical response. Different variables such as Recycled Concrete Aggregate (RCA) content, pre-wetting, confinement level, concrete age and RCA source are analyzed and their implication on the main mechanical properties is discussed. Then, the static and cyclic behavior of FRP-confined RAC members is reviewed. Considering the static behavior, columns under concentric compression and eccentric compression are analyzed. Finally, the limited number of results available from the literature are employed to derive a prediction model for the strength of multi-axial stressed and confined RAC by considering the RCA content as the main governing variable. The need for further research is pointed out at the end of the paper.
Objective
To investigate the potential mechanism of the effect of metabolic syndrome (MetS) on prostate volume (PV) and the risk of benign prostatic hyperplasia (BPH)/lower urinary tract symptoms ...(LUTS) and the relationships of MetS and the major pathogenic factors of MetS with the clinical progression of BPH/LUTS in older Chinese men.
Subjects and Methods
We analyzed clinical data obtained from 506 ostensibly healthy men who underwent routine health check‐ups and recruited 415 subjects from a group of previously studied men after 4 years. We evaluated the associations of major pathological factors of MetS, including insulin resistance, subclinical inflammatory state, and sex hormone changes, with PV, the risk of BPH and the clinical progression of BPH/LUTS by using multiple linear regression and logistic regression.
Results
After adjustment for age, insulin, HOMA (homeostatic model assessment) index, leptin, resistin, adiponectin, C‐reactive protein, tumor necrosis factor‐α (TNF‐α), sex hormone‐binding globulin, and testosterone levels were significantly associated with PV (all P < .05), and in the age‐adjusted logistic regression model, positive associations of resistin and TNF‐α with BPH/LUTS were found (OR, 1.662, P = .007 and OR, 1.044, P < .001, respectively). Predictors of BPH/LUTS clinical progression were significantly correlated with MetS and TNF‐α. The group with higher TNF‐α levels had a higher rate of newly diagnosed BPH (9.5% vs 19.1%, P = .006) and a greater increase in PV levels (0.61 ± 0.08 vs 1.09 ± 0.35 cm3, P <.001) after 4 years.
Conclusions
MetS and its pathological factors were associated with an increased PV and an increased risk of BPH/LUTS that is more prone to clinical progression. TNF‐α may serve as an early biological indicator to identify which patients with BPH/LUTS are at higher risk of unfavorable outcomes.
Abstract
Total testosterone levels decline with age, while prostate volume and the prevalence of benign prostatic hyperplasia increase with age. We sought to investigate the correlation of serum ...testosterone levels with prostate volume in aging men. We analyzed clinical data obtained from 416 ostensibly healthy men who underwent routine health check-ups and recruited and collected data from these subjects 4 years later. We analyzed the correlation between prostate volume and relevant factors, as well as the correlation between changes in prostate volume and low testosterone over a 4-year period. Men with low testosterone had significantly larger prostate volume than those in the normal testosterone group (26.86 ± 8.75 vs. 24.06 ± 6.77
P
= 0.02), and subjects with low testosterone had significantly higher levels of obesity-related factors, including waist circumference, body mass index, and insulin (all
P
< 0.001). After adjustment for age, testosterone level was negatively correlated with prostate volume (
P
= 0.004), and prostate volume and 4-year changes in prostate volume were associated with low testosterone. With increased testosterone level, prostate volume showed a significant linear decreasing trend. These findings provide evidence of the relationship between testosterone and prostate volume. Additional large studies are needed to confirm these preliminary results.
X-linked inhibitor of apoptosis (XIAP) is a vital factor in the anti-apoptosis mechanism of tumors and is highly expressed in renal cell carcinoma (RCC). However, the mechanism through which XIAP ...regulates DNA damage repair is unknown. This study investigated the regulatory mechanism of XIAP in etoposide-induced apoptosis in two Caki-1 cell lines with high or low XIAP expression.
The two cell lines were established using RNA interference technology. The differentially expressed proteins in the two cell lines were globally analyzed through an isobaric tags for relative and absolute quantitation-based quantitative proteomics approach. Proteomic analysis revealed 255, 375, 362, and 5 differentially expressed proteins after 0, 0.5, 3, and 12 h of drug stimulation, respectively, between the two cell lines. The identified differentially expressed proteins were involved in numerous biological processes. In addition, the expression of histone proteins (H1.4, H2AX, H3.1, H3.2, and H3.3) was drastically altered, and the effects of XIAP silencing were accompanied by the marked downregulation of H2AX. Protein-protein interactions were assessed and confirmed through immunofluorescence and Western blot analyses.
The results suggested that XIAP may act as a vital cell signal regulator that regulates the expression of DNA repair-related proteins, such as H2AX, and influences the DNA repair process.
Given these functions, XIAP may be the decisive factor in determining the sensitivity of RCC cell apoptosis induction in response to chemotherapeutic agents.
Metabolic syndrome (MetS) and serum prostate-specific antigen (PSA) levels are correlated. To investigate the underlying effect of MetS on PSA levels, the relationship between the major pathogenic ...factors of MetS and serum PSA levels was studied.
A total of 506 ostensibly healthy men who underwent routine health check-ups were recruited to this study. We evaluated the effect of the major pathogenic factors of MetS, which included insulin resistance, a subclinical inflammatory state and sexual hormone changes, on serum PSA levels by using linear regression analysis and multivariate analysis after adjusting for age, BMI and prostate volume.
When simultaneously adjusting for age, BMI, prostate volume and high-density lipoprotein cholesterol, serum insulin levels and SHBG levels were inversely correlated with serum PSA levels (P = 0.049 and P = 0.004, respectively), and testosterone levels were positively correlated with serum PSA levels (P = 0.039). In multivariate regression models, serum insulin levels and serum SHBG levels were significantly associated with serum PSA levels (both P < 0.001).
Among the major pathogenic factors of metabolic syndrome, insulin resistance and sexual hormone changes may be the most significant contributors to the decline in serum PSA levels.
•A fiber section-based nonlinear finite element model was developed to investigate the mechanical behavior of reinforced RRAC columns.•Multi-parametric study was performed to investigate the ...compressive behavior of RRAC columns.•A grey correlation analysis was used to evaluate the parametric sensitivity of the compressive behavior of RRAC columns.•The results show that the replacement of conventional concrete with RAC affects the overall compressive behavior of RC columns only slightly.•The method used for considering the additional water absorption of recycled aggregates has a significant influence on the compressive load capacity of RRAC columns.
This paper presents a critical assessment of the compressive behavior of reinforced recycled aggregate concrete (RRAC) columns. Previous research has demonstrated that recycled aggregate concrete (RAC), manufactured using crushed concrete aggregates obtained from construction and demolition waste, can be a feasible and environmentally friendly alternative to conventional concrete for the use in structural applications. Currently, very limited information is available in the literature about the methods to be used for designing RC elements manufactured with recycled concrete aggregates. With the aim of extending the available experimental data, a fiber section based nonlinear finite element (FE) model was developed so as to provide in-depth insights into the compressive behavior of RRAC columns. First, a comparison between simulation results of the compressive behavior of RRAC columns and available experimental results were made to validate the FE model. Then, using the validated FE model, a parametric study was performed to investigate the effects of different recycled concrete aggregate (RCA) contents, volumetric ratio and yield strength of longitudinal steel reinforcement, and spacing and yield strength of transverse steel reinforcement on the compressive behavior and load capacity of RRAC columns. Finally, based on the limited available experimental database, a grey correlation analysis was used to evaluate the parametric sensitivity of the compressive behavior of RRAC columns. The experimental and numerical investigations demonstrate that the method used for considering the additional water absorption of RCAs in manufacturing RAC has a significant influence on the compressive load capacity of RRAC columns and that the influence of the RCA content on the compressive load capacity of RRAC columns is lower when compared with other important parameters but this effect should not be ignored in modeling the behavior of RRAC columns.
•A computer program for the nonlinear analysis of square RACFST columns was developed.•CFST structures can realize the economic savings by working with high RCA contents.•Strengthening measures need ...to be developed to ensure the ductility of 1:1-scaled square RACFST columns.
Concrete-filled steel tubes can improve the mechanical behavior in terms of strength, stiffness, ductility and energy dissipation for the initial deficiencies of recycled aggregate concrete compared with natural aggregate concrete. The firsthand seismic performance indices on recycled aggregate concrete-filled steel tubular (RACFST) structural members are very limited due to the rare experimental results reported in the literature. To this end, a computer-assisted program for the nonlinear analysis of square RACFST columns was developed by employing SeismoStruct Software, to emphasize the effect of recycled coarse aggregate (RCA) content on the behavior of recycled aggregate concrete and the confinement effect provided by outer tubes on core concrete. Concerning the hysteretic curves, load carrying capacity and ductility, comparisons between simulation results and existing experimental ones were made to examine the rationality of numerical square RACFST model. The analysis results show that the numerical model can well simulate and predict the seismic behavior of square RACFST columns. To obtain more structural performance indices, the parametric study was performed to investigate the effects of RCA content and pre-wetting, steel yield strength, length-diameter ratio, diameter-thickness ratio, axial load ratio and structural size ratio on the hysteretic characteristic, initial lateral stiffness, ultimate lateral load and ductility of cyclic bended square RACFST columns. Both the measurement and simulation results demonstrate that concrete-filled steel tubular columns employing recycled coarse aggregates have laudable seismic behavior, and it is feasible to apply and promote the recycled aggregate concrete into concrete-filled steel tube structures in anti-seismic regions.
Concrete-filled steel tubular structural members can be recognized as an effective mean to improve the mechanical behavior in terms of strength, stiffness, ductility, and energy dissipation for the ...initial recycle aggregate concrete deficiencies compared with natural aggregate concrete. A small-scale model of square concrete-filled steel tubular column–reinforced concrete beam frame realized employing 100% recycled coarse aggregates was tested under combined axial loads and cyclic reversed lateral flexure. The failure modes, plastic hinges sequence, hysteresis loop, skeleton curve, stiffness degeneration, energy dissipation capacity, and ductility of the frame were presented and analyzed in detail. The structural behavior of square concrete-filled steel tubular column–reinforced concrete beam frame with 100% recycled coarse aggregates was compared with circular concrete-filled steel tubular column–reinforced concrete beam frame made with 100% recycled coarse aggregates. A fiber-based program model for the nonlinear analysis of concrete-filled steel tubular column–reinforced concrete beam frames incorporating recycled coarse aggregates was developed using SeismoStruct, to highlight the effect of recycled coarse aggregate content on mechanical behavior of recycled aggregate concrete and the confinement effect provided by outer tubes on core concrete. The analysis results show that the numerical model can well simulate and predict the seismic behavior of concrete-filled steel tubular column–reinforced concrete beam frames with 100% recycled coarse aggregate content. Both experimental and numerical results demonstrate that concrete-filled steel tubular column–reinforced concrete beam frames with large content of recycled coarse aggregates have a receivable seismic performance, and it is feasible to apply and popularize recycled aggregate concrete into concrete-filled steel tubular structures in seismic regions.
(−)-Epigallocatechin gallate (EGCG), a catechin polyphenol compound, represents the main ingredient of green tea extract. Although EGCG has been shown to be growth inhibitory in a number of tumor ...cell lines, it is not clear whether the effect is cancer-specific. In this study we compared the effect of EGCG on the growth of SV40 virally transformed WI38 human fibroblasts (WI38VA) with that of normal WI38 cells. The IC
50 value of EGCG was estimated to be 120 and 10
μM for WI38 and WI38VA cells, respectively. Thus, EGCG at 40
μM completely inhibited the growth of WI38VA cells, but had little or no inhibitory effect on the growth of WI38 cells. Similar differential growth inhibition was also observed between a human colorectal cancer cell line (Caco-2), a breast cancer cell line (Hs578T) and their respective normal counterparts. EGCG at a concentration range of 40–200
μM induced a significant amount of apoptosis in WI38VA cultures, but not in WI38 cultures, as determined by terminal deoxynucleotidyl transferase assay. After exposure to EGCG at 200
μM for 8 h, more than 50% of WI38VA cells in a confluent culture became apoptotic. In contrast, less than 1% of WI38 cells displayed apoptotic labeling under the same condition. EGCG did not affect the serum-induced expression of c-fos and c-myc genes in normal WI38 cells. However, it significantly enhanced their expression in transformed WI38VA cells. It is possible that differential modulation of certain genes, such as c-fos and c-myc, may cause differential effects of EGCG on the growth and death of cancer cells.
Chronic allograft nephropathy (CAN) is a major cause of graft loss following kidney transplantation and may result from the interactions of various immune and non-immune factors. The aim of the ...present study was to establish an in vitro model of glomerular mesangial cell injury in order to examine the gene expression levels of indoleamine 2,3-dioxygenase (IDO), heme oxygenase-1 (HO-1) and interleukin-7 (IL-7) in mesangial cells during the healing process as well as to investigate the effects of various immunosuppressants on the expression of these genes. The HBZY-1 glomerular mesangial cell line was pre-treated in vitro with cytochalasin B for 2 h to induce reversible damage. Following the pre-treatment, the HBZY-1 cells were divided into five groups: Blank control group, cyclosporine A (CsA) group, tacrolimus (Tac) group, mycophenolate mofetil (MMF) group and rapamycin (RAPA) group. After treating the mesangial cells with each immunosuppressive drug for 6, 12 or 24 h, the mRNA and protein expression levels of IDO, HO-1 and IL-7 were examined using reverse transcription quantitative polymerase chain reaction (RT-qPCR), western blot and immunohistochemical analyses. The results showed that expression levels of HO-1 were significantly upregulated in response to treatment with CsA, FK506, RAPA and MMF, whereas the expression levels of IL-7 were markedly downregulated by treatment with the above immunosuppressants. CsA, FK506 and MMF significantly enhanced the expression levels of IDO, whereas RAPA exhibited no apparent effect on IDO. The present study may contribute to the understanding of the pathogenesis of CAN and provide novel strategies for the prevention and treatment of CAN.
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