A simplified method for determining the acceleration amplitudes of long-span floor system under walking/running loads

Liang Cao,Y. Frank Chen 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.75 No.3

Modern long-span floor system typically possesses low damping and low natural frequency, presenting a potential vibration sensitivity problem induced by human activities. Field test and numerical analysis methods are available to study this kind of problems, but would be inconvenient for design engineers. This paper proposes a simplified method to determine the acceleration amplitudes of long-span floor system subjected to walking or running load, which can be carried out manually. To theoretically analyze the acceleration response, the floor system is simplified as an anisotropic rectangular plate and the mode decomposition method is used. To facilitate the calculation of acceleration amplitude aP, a coefficient αwmn or αRmn is introduced, with the former depending on the geometry and support condition of floor system and the latter on the contact duration tR and natural frequency. The proposed simplified method is easy for practical use and gives safe structural designs.

Compound glycyrrhizin injection for improving liver function in children with acute icteric hepatitis: A systematic review and meta-analysis

Liang Shi-Bing,Hou Wen-Bin,Zheng Ruo-Xiang,Liang Chang-Hao,Yan Li-Jiao,Wang Hao-Nan,Cao Hui-Juan,Han Mei,Robinson Nicola,Liu Jian-Ping 한국한의학연구원 2022 Integrative Medicine Research Vol.11 No.1

Background: Compound glycyrrhizin injection (CGI) is a preparation with glycyrrhizin as the main active ingredient extracted from licorice. As clinical trials suggest that CGI is effective in improving liver function for acute icteric hepatitis in children (AIHC), this systematic review aimed to evaluate and verify its therapeutic effects and safety. Methods: Six electronic databases were searched from their inception to 15 May 2021. Randomized controlled trials (RCTs) assessing therapeutic effects and safety of CGI for AIHC were included. The risk of bias for each trial was assessed using the Cochrane Risk of Bias Tool 2.0. Primary outcomes were indexes related to liver function, including total bilirubin (TBiL), alanine aminotransferase (ALT) and aspartate transaminase (AST). RevMan 5.4 software was used for data analyses. The certainty of the evidence was assessed using the online GRADEpro tool. Results: Six RCTs involving 608 children were included. The overall bias was assessed as having “high risk of bias” in all trials. All trials compared the combination of CGI and conventional western medicine (CWM) with CWM alone. Regarding the effects of CGI for AIHC, results showed that CGI plus CWM was superior to CWM alone in reducing the levels of TBiL (mean difference (MD) = -8.19 mmol/L, 95% CI -9.86 to -6.53), ALT (MD = -24.09 U/L, 95% CI -30.83 to -17.34) and AST (MD = -18.67 U/L, 95% CI -21.88 to -15.45). No trial reported adverse events. The certainty of the evidence for outcomes were all evaluated as low or very low. Conclusion: CGI may have adjuvant therapeutic effects on improving the liver function of children with AIHC. There is no evidence to determine the safety of CGI for AIHC. As current evidence is weak, further well-designed RCTs are required for verification of the therapeutic effects of CGI. Background: Compound glycyrrhizin injection (CGI) is a preparation with glycyrrhizin as the main active ingredient extracted from licorice. As clinical trials suggest that CGI is effective in improving liver function for acute icteric hepatitis in children (AIHC), this systematic review aimed to evaluate and verify its therapeutic effects and safety. Methods: Six electronic databases were searched from their inception to 15 May 2021. Randomized controlled trials (RCTs) assessing therapeutic effects and safety of CGI for AIHC were included. The risk of bias for each trial was assessed using the Cochrane Risk of Bias Tool 2.0. Primary outcomes were indexes related to liver function, including total bilirubin (TBiL), alanine aminotransferase (ALT) and aspartate transaminase (AST). RevMan 5.4 software was used for data analyses. The certainty of the evidence was assessed using the online GRADEpro tool. Results: Six RCTs involving 608 children were included. The overall bias was assessed as having “high risk of bias” in all trials. All trials compared the combination of CGI and conventional western medicine (CWM) with CWM alone. Regarding the effects of CGI for AIHC, results showed that CGI plus CWM was superior to CWM alone in reducing the levels of TBiL (mean difference (MD) = -8.19 mmol/L, 95% CI -9.86 to -6.53), ALT (MD = -24.09 U/L, 95% CI -30.83 to -17.34) and AST (MD = -18.67 U/L, 95% CI -21.88 to -15.45). No trial reported adverse events. The certainty of the evidence for outcomes were all evaluated as low or very low. Conclusion: CGI may have adjuvant therapeutic effects on improving the liver function of children with AIHC. There is no evidence to determine the safety of CGI for AIHC. As current evidence is weak, further well-designed RCTs are required for verification of the therapeutic effects of CGI.

Vibration performance characteristics of a long-span and light-weight concrete floor under human-induced loads

Liang Cao,Jie-Peng Liu,Xu-Hong Zhou,Y. Frank Chen 국제구조공학회 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.65 No.3

An extensive research was undertaken to study the vibration serviceability of a long-span and light-weight floor subjected to human loading experimentally and numerically. Specifically, heel-drop test was first conducted to capture the floor’s natural frequencies and damping ratios, followed by jumping and running tests to obtain the acceleration responses. In addition, numerical simulations considering walking excitation were performed to further evaluate the vibration performance of a multi-panel floor under different loading cases and walking rates. The floor is found to have a high frequency (11.67 Hz) and a low damping ratio (2.32%). The comparison of the test results with the published data from the 1997 AISC Design Guide 11 indicates that the floor exhibits satisfactory vibration perceptibility overall. The study results show that the peak acceleration is affected by the walking path, walking rate, and adjacent structure. A simpler loading case may be considered in design in place of a more complex one.

Practical formula for determining peak acceleration of footbridge under walking considering human-structure interaction

Liang Cao,Hailei Zhou,Y. Frank Chen 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.83 No.6

In this paper, an analytical formulation is proposed to predict the vertical vibration response due to the pedestrian walking on a footbridge considering the human-structure interaction, where the footbridge and pedestrian are represented by the Euler beam and linear oscillator model, respectively. The derived coupled equation of motion is a nonlinear fourth-order partial differential equation. An uncoupled solution strategy based on the combined weighted residual and perturbation method) is proposed to reduce the tedious computation, which allows the separate integration between the bridge and pedestrian subsystems. The theoretical study demonstrates that the pedestrian subsystem can be treated as a structural system with added mass, damping, and stiffness. The analysis procedure is then applied to a case study under the conditions of single pedestrian and multi pedestrians, and the results are validated and compared numerically. For convenient vibration design of a footbridge, the simplified peak acceleration formula and the idea of decoupling problem are thus proposed.

Nonlegumes Respond to Rhizobial Nod Factors by Suppressing the Innate Immune Response

Liang, Yan,Cao, Yangrong,Tanaka, Kiwamu,Thibivilliers, Sandra,Wan, Jinrong,Choi, Jeongmin,Kang, Chang ho,Qiu, Jing,Stacey, Gary American Association for the Advancement of Scienc 2013 Science Vol.341 No.6152

<P><B>Stealth Nod Factor Recognition</B></P><P>Legumes' symbiotic interaction with nitrogen fixing bacteria supplies the plant with nitrogen. Many important crop plants, however, cannot establish these symbioses and, thus, agriculture depends on externally applied fertilizers. Surprisingly, <B>Liang <I>et al.</I></B> (p. 1384, published online 5 September) found that several nonleguminous plants, including <I>Arabidopsis</I>, tomato, and corn, were able to respond to the same Nod factors that initiate the microbial symbiosis in soybean.</P>

Expression of Pituitary Tumor Transforming Gene 1 is an Independent Factor of Poor Prognosis in Localized or Locally Advanced Prostate Cancer Cases Receiving Hormone Therapy

Cao, Xi-Liang,Gao, Jiang-Ping,Wang, Wei,Xu, Yong,Shi, Huai-Yin,Zhang, Xu Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.7

We investigated the prognostic value of pituitary tumor transforming gene 1 (PTTG1) expression according to clinicopathological features among localized or locally advanced prostate cancer cases receiving hormone therapy. A retrospective study involved 64 patients receiving combined androgen blockade treatment was performed. PTTG1 expression was determined by immunohistochemical staining using initial needle biopsy specimens for diagnosis. Associations of PTTG1 with various clinicopathological features and disease-free survival were examined via uni- and multivariate analyses. No association between PTTG1 expression and clinical T stage, Gleason score, pretreatment PSA levels, risk groups was found (p =0.682, 0.184, 0.487, 0.571, respectively). Univariate analysis revealed that increased PTTG1 expression, T3 stage and high risk group were associated with increased risk of disease progression (p =0.000, 0.042, and 0.001), and high PSA level had a tendency to predict disease progression (p =0.056). Cox hazard ratio analysis showed that PTTG1 low expression (p =0.002), PTTG1 high expression (p =0.000) and high risk group (p =0.0147) were significantly related to decreased disease-free survival. In conclusion, PTTG1 expression determined by immunohistochemical staining in needle biopsy specimens for diagnosis is a negative prognostic factor for progression in localized or locally advanced prostate cancer receiving hormone therapy.

Vibration performance characteristics of a long-span and light-weight concrete floor under human-induced loads

Cao, Liang,Liu, Jiepeng,Zhou, Xuhong,Chen, Y. Frank Techno-Press 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.65 No.3

An extensive research was undertaken to study the vibration serviceability of a long-span and light-weight floor subjected to human loading experimentally and numerically. Specifically, heel-drop test was first conducted to capture the floor's natural frequencies and damping ratios, followed by jumping and running tests to obtain the acceleration responses. In addition, numerical simulations considering walking excitation were performed to further evaluate the vibration performance of a multi-panel floor under different loading cases and walking rates. The floor is found to have a high frequency (11.67 Hz) and a low damping ratio (2.32%). The comparison of the test results with the published data from the 1997 AISC Design Guide 11 indicates that the floor exhibits satisfactory vibration perceptibility overall. The study results show that the peak acceleration is affected by the walking path, walking rate, and adjacent structure. A simpler loading case may be considered in design in place of a more complex one.

Numerical study on the walking load based on inverted-pendulum model

Liang Cao,Jie-Peng Liu,Xiaolin Zhang,Y. Frank Chen 국제구조공학회 2019 Structural Engineering and Mechanics, An Int'l Jou Vol.71 No.3

In this paper, an inverted-pendulum model consisting of a point supported by spring limbs with roller feet is adopted to simulate human walking load. To establish the kinematic motion of first and second single and double support phases, the Lagrangian variation method was used. Given a set of model parameters, desired walking speed and initial states, the Newmark-β method was used to solve the above kinematic motion for studying the effects of roller radius, stiffness, impact angle, walking speed, and step length on the ground reaction force, energy transfer, and height of center of mass transfer. The numerical simulation results show that the inverted-pendulum model for walking is conservative as there is no change in total energy and the duration time of double support phase is 50-70% of total time. Based on the numerical analysis, a dynamic load factor αwi is proposed for the traditional walking load model.

Fault-tolerant Control for Nonlinear Systems with Multiple Intermittent Faults and Time-varying Delays

Liang Cao,Youqing Wang 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.2

This study investigates a new fault-tolerant control method for uncertain nonlinear systems with multiple intermittent faults and time-varying delays. The considered intermittent faults appear in sensors and actuators simultaneously. A Markov chain is used to describe the random occurrence and disappearance of intermittent faults. The uncertain nonlinear system with intermittent faults is augmented as a Markovian jump system. By using H-infinity control theory and linear matrix inequality (LMI), we design fault tolerant controllers to make augmented Markovian jump system work steadily. Several sufficient conditions for stochastic stability with given H-infinity performance index and the existence of output-feedback controllers are derived. The effectiveness of the proposed fault-tolerant method is validated by a continuously stirred tank reactor (CSTR).

Experimental study on vibration serviceability of steel-concrete composite floor

Liang Cao,Jie-Peng Liu,Y. Frank Chen 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.74 No.5

In this study, on-site testing was carried out to investigate the vibration serviceability of a composite steel-bar truss slab with steel girder system. Impulse excitations (heel-drop and jumping) and steady-state motion (walking and running) were performed to capture the primary vibration parameters (natural frequency and damping ratio) and distribution of peak acceleration. The composite floor possesses low frequency (<8.3Hz) and damping ratio (<2.47%). Based on experimental, theoretical, and numerical analyses on fundamental natural frequency, the boundary condition of SCSS (i.e., three edges simply supported and one edge clamped) is deemed more comparable substitutive for the investigated composite floor. Walking and running excitations by one person (single excitation) were considered to evaluate the vibration serviceability of the composite floor. The measured acceleration results show a satisfactory vibration perceptibility. For design convenience and safety, a crest factor βrp describing the ratio of peak acceleration to root-mean-square acceleration induced from the walking and running excitations is proposed. The comparisons of the modal parameters determined by walking and running tests reveal the interaction effect between the human excitation and the composite floor.