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Summary: Gene expression is dynamically regulated in a variety of mammalian physiologies. During mammalian aging, there are changes that occur in protein expression that are highly controlled by the regulatory steps in transcription, post‐transcription, and post‐translation. Although there are global profiles of human transcripts during the aging processes available, the mechanism(s) by which transcripts are differentially expressed between young and old cohorts remains unclear. Here, we report on N6‐methyladenosine (m6A) RNA modification profiles of human peripheral blood mononuclear cells (PBMCs) from young and old cohorts. An m6A RNA profile identified a decrease in overall RNA methylation during the aging process as well as the predominant modification on proteincoding mRNAs. The m6A‐modified transcripts tend to be more highly expressed than nonmodified ones. Among the many methylated mRNAs, those of DROSHA and AGO2 were heavily methylated in young PBMCs which coincided with a decreased steady‐state level of AGO2 mRNA in the old PBMC cohort. Similarly, downregulation of AGO2 in proliferating human diploid fibroblasts (HDFs) also correlated with a decrease in AGO2 mRNA modifications and steady‐state levels. In addition, the overexpression of RNA methyltransferases stabilized AGO2 mRNA but not DROSHA and DICER1 mRNA in HDFs. Moreover, the abundance of miRNAs also changed in the young and old PBMCs which are possibly due to a correlation with AGO2 expression as observed in AGO2‐depleted HDFs. Taken together, we uncovered the role of mRNA methylation on the abundance of AGO2 mRNA resulting in the repression of miRNA expression during the process of human aging. [ABSTRACT FROM AUTHOR]

Since the 1980s, growing evidence suggested that the cellular localization of proteins determined their activity and biological functions. In a classical view, a protein is characterized by the single cellular compartment where it primarily resides and functions. It is now believed that when proteins appear in different subcellular locations, the cells surpass the expected activity of proteins given the same genomic information to fulfill complex biological behavior. Many proteins are recognized for having the potential to exist in multiple locations in cells. Dysregulation of translocation may cause cancer or contribute to poorer cancer prognosis. Thus, quantitative and comprehensive assessment of dynamic proteins and associated protein movements could be a promising indicator in determining cancer prognosis and efficiency of cancer treatment and therapy. This review will summarize these so-called moonlighting proteins, in terms of a coupled intracellular cancer signaling pathway. Determination of the detailed biological intracellular and extracellular transit and regulatory activity of moonlighting proteins permits a better understanding of cancer and identification of potential means of molecular intervention. [ABSTRACT FROM AUTHOR]

A detailed study on the dynamic characteristics of passive damping devices of TLCDs with different blocking ratios in orifices is analytically and experimentally conducted for investigation of the optimal control performance of the TLCDs for a wide range of wind loading. In the analytical phase of this study, the control performance is thoroughly investigated for a single degree-of-freedom primary structure equipped with a TLCD for varying intensities of wind loading and blocking ratios. It is verified that the passive-type TLCD with an optimally designed small blocking ratio still shows good performance for strong wind excitation. Next, a series of experiments are carried out to investigate the control performance of a prototype of the TLCD using harmonic and white noise wind excitation and blocking ratios in the orifice by use of a shake table. The damping ratio of the TLCD with various blocking ratios is predicted by the head loss coefficient obtained from the measured data and used for estimating the control efficiency. It is confirmed that the optimal control performance is maintained under conditions of strong wind excitation and an optimally designed small blocking ratio. [ABSTRACT FROM AUTHOR]

Abstract: A new design procedure of a two-way liquid damper which reduces wind-induced responses of a tall building is presented as a quick guide for structural engineers. The two-way liquid damper combines the (1) Tuned Liquid Column Damper (TLCD) in which liquid moves through a U-shape tube and the (2) Tuned Sloshing Damper (TSD) in which liquid sloshes within a container, respectively for two orthogonal directions. Dimensions of the damper, such as horizontal liquid column length and the thickness of the TLCD, the width of the TSD, and liquid height are determined given the condition of tuning the natural frequencies of liquid motion in the damper to those of the building. The design procedure is a trial and error process of satisfying geometrical constraints (i.e., maximum space where the damper is installed) and varying controlled response factors (i.e., performance of vibration attenuation). A design example of the damper is illustrated in the paper for its installation at a 64-story reinforced-concrete residential building. [Copyright &y& Elsevier]

Transforming growth factor-β (TGF-β) modulates diverse cell physiological processes and plays a complicated role in tumor development. It has been well established that TGF-β inhibits cell proliferation in normal and early stage carcinoma and facilitates tumor metastasis in late-stage carcinoma. Therefore, blocking TGF-β signaling in advanced stage carcinogenesis provides a potentially interesting chemotherapeutic strategy. We aimed to determine the effect of tolfenamic acid (TA) on TGF-β-induced protumorigenic activity. Here, we demonstrate that TA attenuates tumor-promoting effects of TGF-β in cancer cells. Further observation indicates TA blocks the TGF-β/Smad pathway, and this blockage is mainly attributed to the interference of TGF-β1-driven phosphorylation of Smad2/3. We also show that TA could exert this effect on cancer cell lines from several different origins and that TA is much better than other non-steroidal anti-inflammatory drugs with respect to inhibition of TGF-β1-induced Smad2 phosphorylation. Finally, extracellular signal-regulated kinase mitogen-activated protein kinase plays a role in TA-induced suppression of Smad2/3 phosphorylation and subsequent nuclear accumulation of Smad2/3 in response to TGF-β1. Our study provides a possible mechanism by which TA affects anticancer activity by inhibiting the TGF-β pathway and sheds light on the application of TA for cancer patients. [ABSTRACT FROM AUTHOR]

3,3'-Diindolylmethane (DIM) is a major in vivo condensation product of indole-3-carbinol, which is present in cruciferous vegetables. Although these compounds have been widely implicated in antitumorigenic and proapoptotic properties in animal as well as in vitro models of cancer, the underlying cellular mechanisms regulated by DIM are only partially understood. Activating transcription factor 3 (ATF3) is a member of the ATF/c-AMP response element-binding (CREB) subfamily of the basic-region leucine zipper family and has been known to induce apoptosis in human colorectal cancer (CRC) cells. The present study was performed to elucidate the molecular mechanism of ATF3 induction by DIM in human CRC cells. The DIM treatment induced apoptosis and induced ATF3 gene expression at protein and messenger RNA levels. DIM increased ATF3 promoter activity, and the region of -84 to +34 within ATF3 promoter was responsible for promoter activation by DIM. This region contained an ATF binding site. Deletion and point mutation of the ATF binding site (-23 to -16) abolished ATF3 promoter activation by DIM, and overexpression of ATF4 enhanced ATF3 transactivation. Chromatin immunoprecipitation assay confirmed the binding of ATF4 in the ATF3 promoter. Inhibition of ATF4 expression by small interference RNA results in repression of DIM-induced ATF3 expression. The current study demonstrates that DIM stimulates ATF3 expression through ATF4-mediated pathway and subsequently induces apoptosis in human CRC cells. [ABSTRACT FROM AUTHOR]

Abstract: 3,3′-Diindolylmethane (DIM) is a major in vivo condensation product of indole-3-carbinol, which is present in cruciferous vegetables. Although these compounds have been widely implicated in antitumorigenic and proapoptotic properties in animal as well as in vitro models of cancer, the underlying cellular mechanisms regulated by DIM are only partially understood. Activating transcription factor 3 (ATF3) is a member of the ATF/c-AMP response element-binding (CREB) subfamily of the basic-region leucine zipper family and has been known to induce apoptosis in human colorectal cancer (CRC) cells. The present study was performed to elucidate the molecular mechanism of ATF3 induction by DIM in human CRC cells. The DIM treatment induced apoptosis and induced ATF3 gene expression at protein and messenger RNA levels. DIM increased ATF3 promoter activity, and the region of −84 to +34 within ATF3 promoter was responsible for promoter activation by DIM. This region contained an ATF binding site. Deletion and point mutation of the ATF binding site (−23 to −16) abolished ATF3 promoter activation by DIM, and overexpression of ATF4 enhanced ATF3 transactivation. Chromatin immunoprecipitation assay confirmed the binding of ATF4 in the ATF3 promoter. Inhibition of ATF4 expression by small interference RNA results in repression of DIM-induced ATF3 expression. The current study demonstrates that DIM stimulates ATF3 expression through ATF4-mediated pathway and subsequently induces apoptosis in human CRC cells. [Copyright &y& Elsevier]

Nordihydroguaiaretic acid (NDGA), a well-known lipoxygenase inhibitor, exerts pleiotropic effects on various cellular events. It has also been known that NDGA suppresses immune response in lipopolysaccharide (LPS)-challenged immune cells. Although the immunosuppressive activity of NDGA was suggested to be related with its antioxidant activity, the precise mechanism for its diverse effects on immune system has not been clarified yet. Since transforming growth factor–β–activated kinase 1 (TAK1) is an essential intracellular signaling component in mediating the immune responses of macrophage and lymphocytes, we asked whether NDGA has specific effect on TAK1 signaling pathway. In this study, we examined the immunosuppressive activity of NDGA in murine macrophage cell line (RAW 264.7) as well as the changes in TAK1 after the NDGA challenge. Our results clearly showed that the LPS-induced iNOS, COX-2, and tumor necrosis factor α (TNF-α) expressions were suppressed and TAK1 was also significantly down-regulated in the presence of NDGA. However, the messenger ribonucleic acid (mRNA) level of TAK1 was not changed. Instead, the protein level was significantly decreased by the treatment of NDGA, and the specific proteasome inhibitor was able to block the decrease in TAK1 level. This result implied the involvement of protein degradation pathway in down-regulation of TAK1 by NDGA. Because NDGA also suppressed c-Jun NH2-terminal protein kinase (JNK) activation caused by LPS treatment in correlation with the decrease in TAK1 level, the immunosuppression exerted by NDGA seemed correlated with its down-regulating effect on TAK1 together with the blockage of NF-κB signaling. [ABSTRACT FROM AUTHOR]

Purpose: The public has paid attention to green tea due to its health benefits. Epigallocatechin-3-gallate (EGCG), the major component of green tea, is well documented to induce apoptosis and cell cycle arrest in cancer cells by targeting multiple signal transduction pathways. However, the detailed mechanism(s) of action needs to be determined. Methods: Cell growth was evaluated by MTT assay, cell cycle analysis, and caspase 3/7 activity. Protein expression was analyzed through Western blotting. Reverse transcription polymerase chain reaction was used for examining mRNA expression of p21 and cyclin D1. The promoter activity of p21 was assessed by the luciferase reporter system. Results: We identified cyclin D1 and p21 as molecular targets of EGCG in human colorectal cancer cells. We observed that cyclin D1 was down-regulated, while p21 expression was up-regulated by EGCG in dose- and time-dependent manners. Furthermore, we found EGCG decreased cyclin D1 protein stability, therefore triggering ubiquitin-dependent proteasomal degradation. Meanwhile, EGCG increased p21 promoter activity, resulting in up-regulation of p21 mRNA and protein, which was likely dependent on extracellular-signal-regulated kinase (ERK), inhibitor of nuclear factor kappa-B kinase (IKK) and phosphoinositide 3-kinase (PI3 K). Conclusion: The data presented here details a novel mechanism by which EGCG inhibits cell growth of colorectal cancer cells. Namely, EGCG-induced cyclin D1 degradation and p21 transcriptional activation partially contribute to growth suppression in these cells. [ABSTRACT FROM AUTHOR]

Abstract: MCC-555 is a novel PPARα/γ dual ligand of the thiazolidinedione class and was recently developed as an anti-diabetic drug with unique properties. MCC-555 also has anti-proliferative activity through growth inhibition and apoptosis induction in several cancer cell types. Our group has shown that MCC-555 targets several proteins in colorectal tumorigenesis including nonsteroidal anti-inflammatory drug (NSAID)-activated gene (NAG-1) which plays an important role in chemoprevention responsible for chemopreventive compounds. NAG-1 is a member of the TGF-β superfamily and is involved in tumor progression and development; however, NAG-1''s roles in pancreatic cancer have not been studied. In this report, we found that MCC-555 alters not only NAG-1 expression, but also p21 and cyclin D1 expression. NAG-1 and p21 expression was not blocked by PPARγ-specific antagonist GW9662, suggesting that MCC-555-induced NAG-1 and p21 expression is independent of PPARγ activation. However, decreasing cyclin D1 by MCC-555 seems to be affected by PPARγ activation. Further, we found that the GC box located in the NAG-1 promoter play an important role in NAG-1 transactivation by MCC-555. Subsequently, we screened several transcription factors that may bind to the GC box region in the NAG-1 promoter and found that KLF4 potentially binds to this region. Expression of KLF4 precedes NAG-1 and p21 expression in the presence of MCC-555, whereas blocking KLF4 expression using specific KLF4 siRNA showed that both NAG-1 and p21 expression by MCC-555 was blocked. In conclusion, MCC-555''s actions on anti-proliferation involve both PPARγ-dependent and -independent pathways, thereby enhancing anti-tumorigenesis in pancreatic cancer cells. [Copyright &y& Elsevier]

Abstract: A tuned liquid column and sloshing damper (TLCSD) is introduced in this study. It shows dynamic behavior of both tuned liquid column damper (TLCD) and tuned liquid damper (TLD) in the direction of two axes perpendicular with each other. As a preliminary study for applying the TLCSD to bidirectional control of building structures, one of objectives of this study is to derive analytical dynamics to investigate coupled effects due to TLCD and TLD. Another objective is to investigate the effect of coupled control force due to TLCD and TLD on the dynamic characteristic of the TLCSD based on analytical dynamics. Shaking table test is undertaken to experimentally grasp dynamic characteristics of TLCSD under white noise excitation with various amplitude levels. Its dynamic characteristics are expressed by the transfer function from the shaking table acceleration to the control force generated from a TLCSD. The analytical dynamics of TLCSD is derived from the equivalent linearized TMD model. The coupled dynamics of TLCSD is expressed in terms of those of both TLCD and TLD. Finally, the key parameters of both TLCD and TLD are identified based on the coupled dynamics proposed in this study, which include the mass ratio of horizontal liquid column to total liquid for a TLCD, and the participation factor of the fundamental liquid sloshing for a TLD and damping ratio for both cases. [ABSTRACT FROM AUTHOR]

Abstract: This study proposed a simple design procedure for determining the required damping force of a friction damper installed in a single-story structure. The analysis model was transformed into an equivalent mass-spring-dashpot system by approximating a nonlinear Coulomb damping force with an equivalent viscous damping force. A closed form solution for the dynamic magnification factor (DMF) for a steady-state response was derived using the energy balance equation. The equivalent viscous damping ratio was defined using the DMF at the natural frequency. The transfer function between input harmonic excitation and output structural response was obtained from the DMF, and the response reduction factor of the root mean square (RMS) of displacements with and without friction dampers was analytically determined. Using the proposed procedure the friction force required for satisfying a given target response reduction factor was obtained. The response reduction factors were obtained for the structures with different natural frequencies subjected to ten earthquake records. Based on the dynamic analysis results, it was concluded that the mean response reduction factors matched well with the target values. [ABSTRACT FROM AUTHOR]

Abstract: A new equivalent linearization technique is proposed for a friction damper–brace system (FDBS) idealized as an elastoplastic system. The proposed equivalent linearization technique utilizes secant stiffness and dissipated energy based on the probability distribution of the extremal displacement of the FDBS. In addition, a conversion scheme to convert an elastically designed equivalent linear systems to a FDBS is given. For comparative study, an existing model update technique based on system identification is modified to constraint elements to be updated. For the purpose of verification, shaking table tests for a small scale three-story shear building model, in which a rotational FDBS is installed, are conducted and equivalent linear systems are obtained using the proposed technique and the model update technique. Natural frequencies, modal damping ratios and response quantities predicted by those equivalent linear systems are compared with experimentally obtained ones. Finally, effects of the maximum friction force on the proposed equivalent linearization technique are investigated through numerical analysis of SDOF systems with a FDBS. [Copyright &y& Elsevier]

The accuracy of the capacity spectrum method (CSM) depends on the precise estimation of equivalent period and damping ratio as well as the modification of the demand spectrum. In this paper, the CSM provided in ATC-40 for estimating the peak inelastic responses is evaluated. First, the effect of equivalent period and damping ratio estimation on the accuracy of the CSM is assessed. Analyses results indicate that the difference between estimation methods is large when the structural nonlinearity is large, but becomes negligible as the hardening ratio increases. Next, the reduction factors provided in ATC-40 and Eurocode are evaluated. It is found that the acceleration responses obtained using the factor of Eurocode is closer to the actual ones than those obtained using the factors of ATC-40. Finally, the demand spectrum is constructed using the peak absolute acceleration and pseudo-acceleration. The results obtained using the peak absolute acceleration is found to be generally larger than those obtained using the pseudo-ones. Since the original CSM generally underestimates the response, the use of peak absolute acceleration in the construction of demand spectrum produces the response relatively closer to the exact one. However, the use of peak absolute acceleration overestimates the response more when the original CSM overestimates the response. [ABSTRACT FROM AUTHOR]

Abstract: In this study, the performance of tuned liquid column dampers (TLCDs) for controlling wind induced responses of a 76-story benchmark building is evaluated. The optimal design parameters such as headloss coefficient, tuning ratio, and mass ratio are numerically obtained by using the white noise and harmonic load in addition to the deterministic wind loads given by the benchmark problem as wind data. Further, the robustness of multiple TLCDs is investigated, and the effects of mass ratio, the number of dampers, central tuning frequency ratio, and the frequency range on the performance of multiple TLCDs are evaluated. Finally, the effectiveness of equivalent linear system for the benchmark building with nonlinear TLCDs is investigated. The equivalent linear system is obtained first in terms of an equivalent linear damping and second in terms of an equivalent single degree of freedom system. [Copyright &y& Elsevier]

Abstract: Non-linear control algorithms with limited control force has been widely explored and has shown promising results, but the probabilistic analysis of such control algorithms has been made restrictively due to their non-linear nature and corresponding difficulty in obtaining analytical solution of the joint probability density function (PDF). In this paper, the method for the probabilistic analysis on the bounded non-linear control algorithm is proposed based on the equivalent non-linear system method and additional regression analysis. Numerical examples show that the proposed approximate joint PDF of the closed-loop system subjected to a Gaussian white noise and a Kanai–Tajimi filtered Gaussian white noise matches closely with the joint PDF obtained statistically. The effectiveness of the bounded non-linear control is also investigated utilizing the calculated approximate joint PDF. Time history analysis results indicate that the same control performance level as the linear controller is achieved when 50% of the maximum control force of the linear controller is used for the non-linear controller. [Copyright &y& Elsevier]

Abstract: In the response control of building structures subjected to strong excitations, the controller saturation problem needs be considered in the design stage. The nonlinearity of saturated controllers, however, makes the exact probabilistic evaluation of control effectiveness difficult. In this study, a stochastic nonlinear control algorithm with bounded control force is proposed and the closed-loop system''s joint probability density function (PDF) governed by the reduced Fokker–Planck equation is derived. Based on the derived joint PDF, the bound of the control force that restricts the first-passage failure probability of the displacement response to a prescribed value is determined. Numerical analyses results show that the proposed controller reduces the maximum required control force considerably compared to the linear controller for the same displacement reduction, and the proposed approximation of the failure probability is considerably accurate. [Copyright &y& Elsevier]

Abstract: This paper presents a modified sliding mode control (SMC) algorithm for vibration control of structures, designed to enhance the control performance of the widely used SMC algorithm. In the modified SMC, the control force is determined so as to meet conditions imposed on the target derivative of the Lyapunov function. A shape function is developed to determine which one of the equivalent and corrective control—which are the two terms comprising the SMC—is the dominant part in controlling structures. Simulation results for linear and nonlinear systems show that the proposed method is able to enhance the control performance of the original SMC. Also, the modified SMC can be applied not only to active control, but also to semi-active control which is suitable for practical application. Moreover, it is observed that the performance is insensitive to the fundamental vibrating period and utilizes less control energy as compared to the original SMC. [Copyright &y& Elsevier]

This paper presents a design process for viscoelastic dampers and experimental test results of a 5-storey single bay steel structure with added viscoelastic dampers. The mechanical properties of viscoelastic dampers and the dynamic characteristics of the model structure were obtained from experiments using harmonic excitation, and the results were used in the design process. The additional damping ratios required to reduce the maximum response of the structure to a desired level were obtained first. Then the size of dampers to realize the required damping ratio was determined using the modal strain energy method by observing the change in modal damping ratio due to the change in damper stiffness. The designed viscoelastic dampers were installed in the first and the second stories of the model structure. The results from experiments using harmonic and band limited random noise indicated that after the dampers were installed the dynamic response of the full-scale model structure reduced as desired in the design process. [Copyright &y& Elsevier]

The purpose of this study is to propose a new method for evaluating the equivalent damping ratio of a structure with supplemental damping devices to assess the vibration control effect quantitatively. The modal-energy-formed Lyapunov function is defined first, and the Riccati matrix and damping rate parameter are derived. Then from its analogy with the definition of a viscous modal damping ratio, the equivalent damping ratio is defined. The proposed approach is applied to estimate the equivalent damping ratio of a structure with various added damping devices. Then a closed-form solution is derived to obtain an equivalent modal damping ratio without carrying out numerical analysis. Results from the numerical analysis verify that the proposed method provides an equivalent damping ratio of a structure equipped with nonlinear as well as linear damping devices quite accurately. [Copyright &y& Elsevier]

Simple Summary: This study addresses the limited understanding of the molecular consequences of low-dose ionizing radiation (LDIR), a relatively unexplored area compared to high-dose radiation methods. The research focuses on profiling RNA species crosslinked to the RNA-binding protein human antigen R (HuR) using LDIR and high throughput RNA sequencing. The developed method involves isolating RNA fragments crosslinked to HuR through LDIR and immunoprecipitation followed by RNA sequencing, revealing rapid degradation of target mRNAs (e.g., PAX6, ZFP91, NR2F6, and CAND2) in human cell lines. Notably, the downregulation of PAX6 and NR2F6 is identified as a protein mediating the beneficial effects of LDIR on cell viability. The findings underscore the significance of investigating post-transcriptional gene regulation under LDIR conditions. Overall, this research introduces a valuable approach for understanding the impact of LDIR on RNA dynamics, shedding light on the molecular consequences and potential therapeutic applications of low-dose ionizing radiation. Although ionizing radiation (IR) is widely used for therapeutic and research purposes, studies on low-dose ionizing radiation (LDIR) are limited compared with those on other IR approaches, such as high-dose gamma irradiation and ultraviolet irradiation. High-dose IR affects DNA damage response and nucleotide–protein crosslinking, among other processes; however, the molecular consequences of LDIR have been poorly investigated. Here, we developed a method to profile RNA species crosslinked to an RNA-binding protein, namely, human antigen R (HuR), using LDIR and high-throughput RNA sequencing. The RNA fragments isolated via LDIR-crosslinking and immunoprecipitation sequencing were crosslinked to HuR and protected from RNase-mediated digestion. Upon crosslinking HuR to target mRNAs such as PAX6, ZFP91, NR2F6, and CAND2, the transcripts degraded rapidly in human cell lines. Additionally, PAX6 and NR2F6 downregulation mediated the beneficial effects of LDIR on cell viability. Thus, our approach provides a method for investigating post-transcriptional gene regulation using LDIR. [ABSTRACT FROM AUTHOR]

In this study, a novel and rapid vision-based sensing strategy is developed exclusively for dynamic wave height measurement of tuned liquid column dampers (TLCDs). The image processing algorithm of the vision-based sensing method simply counts white pixels in a binary image and thus expedites the vision-based wave height measurement. In addition to the experimental achievement, a practical methodology of dynamic characterization for the TLCDs is proposed combining linearized equations for the TLCDs and experimental data measured. An experimental characterization of dynamic behaviors and damping properties of the TLCDs is undertaken utilizing the vision-based sensing developed. [ABSTRACT FROM AUTHOR]

Abstract: Two types of friction-type reinforcing members (FRM) are proposed for the purpose of upgrading wind resistant performance of a transmission tower and verified through cyclic loading tests. First, a suitable installation scheme of the FRM is investigated through numerical analysis. Tower-leg-reinforcing type and brace type installation schemes are examined, and numerical analysis shows that the latter is more effective due to the vertical cantilever type behavior of the transmission tower. Based on this result, two types of the FRMs, dissipating energy in slotted bolted connections, are proposed. The one utilizes the relative displacement between the FRM and the tower leg, and the other utilizes that between the separated angles consisting of the FRM as a slip deformation of the slotted bolted connection. Proposed FRMs are installed on each tower leg of the 1/2 scale substructure models of an actual transmission tower body. From cyclic loading tests, the latter type of the proposed FRMs dissipates energy more effectively and is less sensitive to the work tolerance and initial deformation. [Copyright &y& Elsevier]

Abstract: In this study, a real-time substructuring technique for the shaking table test is proposed. The proposed technique adopts the upper part of the object structure as the experimental substructure and the lower part as the numerical substructure. The force exerted on the interface of the two separated substructures is calculated on-line using the feed-back from an absolute floor acceleration measurement. The acceleration at the interface of the two substructures is calculated through an on-line time history analysis of the numerical substructure and is used as a reference signal in the shaking table controller. The inverse transfer function of the shaking table is employed to minimize the errors between the reference signal and generated ground motion for the experimental substructure. Through a shaking table test, the validity and accuracy of the proposed technique is demonstrated, and a good agreement between experimental and numerical results is obtained. [Copyright &y& Elsevier]

In this paper, a real-time hybrid shaking table testing method (RHSTTM) is experimentally implemented for evaluating the performance of a tuned liquid damper (TLD) controlling a seismically excited building structure. The RHSTTM does not require a physical building structural model in performing the experiment of a TLD–structure interaction system and it only uses a TLD and a shaking table. The structural responses of the interaction system are calculated numerically in real time using an analytical building model, a given earthquake record, and a shear force generated by the TLD, and the shaking table reproduces both the controlled and uncontrolled absolute acceleration of the TLD installed floor by modulating the feedback gain of the shear force signal measured by the load-cell positioned between the TLD and the shaking table. Comparison between the structural responses obtained by the RHSTTM and the conventional shaking table test of a single story steel frame with TLD indicates that the performance of the TLD can be accurately evaluated using the RHSTTM without the physical structural model. Finally, the uncontrolled and TLD-controlled structural responses of a three story structure are obtained by the RHSTTM in both time and frequency domains, showing that TLD can effectively mitigate the seismic responses of building structures. [Copyright &y& Elsevier]

The conventional practice of carrying out a series of trial and error process for design of supplemental dampers requires a lot of computation time and labour. In this study a straightforward design procedure for viscous dampers was developed based on capacity spectrum method in the context of performance based seismic design. The required amount of viscous damping to satisfy given performance acceptance criteria was evaluated from the difference between the overall demand for effective damping and the inherent damping plus the equivalent damping capacity of the structure originated from plastic deformation of each structural member. The proposed method was applied to single-degree-of-freedom systems with various design parameters such as natural period, yield strength, and the stiffness after the first yield. The procedure was also implemented to 10- and 20-storey steel frames for verification of the proposed method. According to the earthquake time history analysis results, the maximum displacements of the model structures with viscous dampers supplied in accordance with the proposed method correspond well with the given target displacements. [ABSTRACT FROM AUTHOR]

Abstract: Background: Nonsteroidal anti-inflammatory drugs (NSAIDs) are well known for treating inflammatory disease and have been reported to have anti-tumorigenic effects. Their mechanisms are not fully understood, but both cyclooxygenase (COX) dependent and independent pathways are involved. Our goal was to shed further light on COX-independent activity. Methods: Human colorectal cancer cells were observed under differential interference contrast microscopy (DICM), fluorescent microscopy, and micro-impedance measurement. Microarray analysis was performed using HCT-116 cells treated with sulindac sulfide (SS). PCR and Western blots were performed to confirm the microarray data and immunohistochemistry was performed to screen for Nesprin-2 expression. Micro-impedance was repeating including Nesprin-2 knock-down by siRNA. Results: HCT-116 cells treated with SS showed dramatic morphological changes under DICM and fluorescent microscopy, as well as weakened cellular adhesion as measured by micro-impedance. Nesprin-2 was selected from two independent microarrays, based on its novelty in relation to cancer and its role in cell organization. SS diminished Nesprin-2 mRNA expression as assessed by reverse transcriptase and real time PCR. Various other NSAIDs were also tested and demonstrated that inhibition of Nesprin-2 mRNA was not unique to SS. Additionally, immunohistochemistry showed higher levels of Nesprin-2 in many tumors in comparison with normal tissues. Further micro-impedance experiments on cells with reduced Nesprin-2 expression showed a proportional loss of cellular adhesion. Conclusions: Nesprin-2 is down-regulated by NSAIDs and highly expressed in many cancers. General significance: Our data suggest that Nesprin-2 may be a potential novel oncogene in human cancer cells and NSAIDs could decrease its expression. [Copyright &y& Elsevier]

The plasma resistance of these commercial quartz glasses was compared, and the product formed by the reaction with plasma was analyzed. Plasma etching was performed in an inductively coupled plasma (ICP) process with a mixture of CF 4 , O 2 , and Ar gases. The mean etching rate of the commercial quartz glasses was 235.5㎚/min, and the p-value of 0.638 determined from the analysis of variance (ANOVA) test showed no statistical significance difference between the impurity content and the etching rate for the samples prepared by the various methods. Thus, it was determined that impurity differences on the ppm level in commercial quartz glasses does not affect the plasma resistance. After plasma etching, the surface roughness was 6.5㎛, which is 45 times greater than the initial surface roughness of 0.14㎛. This is due to the reaction product formed by the chemical reaction of SiO 2 and fluorocarbon during plasma treatment. The product comprised spherical particles with a size of 5–10 ㎛, where silicon oxide and fluoride were the main reaction products, leading to coarsening of the plasma-treated quartz glass. • The purity differences at the ppm level for the quartz had no impact on the plasma resistance properties. • The surface roughness is 6.5㎛ for all quartz glass, which is higher than plasma resistant ceramics. • Particles of silicon oxides and fluorides with sizes of 10–100 ㎚ were formed by reaction between the SiO 2 and CF 4 plasma. • Spherical products with sizes of 5–10 ㎛ size were formed, leading to a coarsening effect. • Dipping due to SiF 4 vaporization and the starting point or falling off point of a reaction product were observed. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, a half-scaled substructure test was performed to evaluate the failure mode of an existing transmission tower subjected to wind load. A loading scheme was devised to reproduce the dead and wind loads acting on the prototype transmission tower. The load was enforced on the model structure using two actuators and a triangular jig mounted on the reduced model. Preliminary numerical analysis was carried out to evaluate the stability and member force of the specimen for the design load. When the substructured transmission tower was loaded by 270% of its maximum allowable buckling load, local buckling occurred in joints of leg members with weak constraints. From the experimental results, such as load–displacement curves, displacements, and strains of members, it was concluded that the local buckling was due to the additional eccentric force caused by unbalanced deformation of the specimen. [Copyright &y& Elsevier]

Abstract: In this study, a seismic design methodology of the friction dampers based on the storey shear force distribution of an elastic building structure is proposed. First, using two normalization methods for the slip-load of a friction damper, numerical analysis of various single degree-of-freedom (SDOF) systems is performed. From this analysis, the effect of the slip-load and brace stiffness is investigated and optimal stiffness ratios of the brace versus primary structure are found. Second, from the numerical analysis for five multistorey building structures of different natural periods and numbers of story, reasonable decision method for the total number of installation floors, location of installation and distribution of slip-loads are drawn. In addition, an empirical equation on the optimal number of installation floor is proposed. Finally, the superiority of the proposed method compared to the existing design method is verified from numerical analysis. [Copyright &y& Elsevier]

Post-transcriptional gene regulation is an important step in the regulation of eukaryotic gene expression. Subcellular compartmentalization of RNA species plays a crucial role in the control of mRNA turnover, spatial restriction of protein synthesis, and the formation of macromolecular complexes. Although long noncoding RNAs (lncRNAs) are one of the key regulators of post-transcriptional gene expression, it is not heavily studied whether localization of lncRNAs in subcellular organelles has functional consequences. Here, we report on mitochondrial lncRNAs whose expression fluctuates in the process of cellular senescence. One of the mitochondrial lncRNAs, RPPH1 RNA, is overexpressed and accumulates in mitochondria of senescent fibroblasts, possibly modulated by the RNA-binding protein AUF1. In addition, RPPH1 RNA overexpression promotes spontaneous replicative cellular senescence in proliferating fibroblasts. Using MS2 aptamer-based RNA affinity purification strategy, we identified putative target mRNAs of RPPH1 RNA and revealed that partial complementarity of RPPH1 RNA to its target mRNAs prevents those mRNAs decay in proliferating fibroblasts. Altogether, our results demonstrate the role of mitochondrial noncoding RNA in the regulation of mRNA stability and cellular senescence. [ABSTRACT FROM AUTHOR]