The analytic radial acceleration relation for galaxy clusters

Recently, a tight correlation between the dynamical radial acceleration and the baryonic radial acceleration in galaxies - the radial acceleration relation - has been discovered. This has been claimed as an indirect support of the modified gravity theories. However, whether the radial acceleration relation could also be found in galaxy clusters is controversial. In this article, we derive and present an analytic radial acceleration relation for the central region of galaxy clusters. We examine the data of some large galaxy clusters and we find that the resulting radial acceleration relation has a very large scatter. Moreover, although the radial acceleration relation for galaxy clusters shows some agreement with the one discovered in galaxies for a certain range of baryonic radial acceleration, their functional forms are somewhat different from each other. This suggests that the radial acceleration relation may not be a universal relation in general.Comment: Accepted in Phys. Rev.

A severe challenge to the MOND phenomenology in our Galaxy

Modified Newtonian Dynamics (MOND) is one of the most popular alternative theories of dark matter to explain the missing mass problem in galaxies. Although it remains controversial regarding MOND as a fundamental theory, MOND phenomenology has been shown to widely apply in different galaxies, which gives challenges to the standard $\Lambda$ cold dark matter model. In this article, we derive analytically the galactic rotation curve gradient in the MOND framework and present a rigorous analysis to examine the MOND phenomenology in our Galaxy. By assuming a benchmark baryonic disk density profile and two popular families of MOND interpolating functions, we show for the first time that the recent discovery of the declining Galactic rotation curve in the outer region ($R \approx 17-23$ kpc) can almost rule out the MOND phenomenology at more than $5\sigma$. This strongly supports some of the previous studies claiming that MOND is neither a fundamental theory nor a universal description of galactic properties.Comment: Accepted in Ap

Development and Validation of an Attitudinal-Profiling Tool for Patients With Asthma

This study was supported and funded by Mundipharma Pte Ltd. Online survey and statistical analysis were performed by Pei-Li Teh, Rachel Howard, Tsin-Li Chua and Jie Sun of Research Partnership Pte Ltd. Medical writing support was provided by Sen-Kwan Tay of Research2Trials Clinical Solutions Pte Ltd. The authors received honoraria from Mundipharma for their participation in the REALISE Asia Working Group meetings and discussions. Prof Price has Board membership with Mundipharma; and had received consultancy and speaker fees, grants and unrestricted funding support from Mundipharma; and payment for manuscript preparation and travel/accommodations/meeting expenses from Mundipharma. Profs Liam and David-Wang are members of the Asia-Pacific Advisory Board of Mundipharma. Profs Cho and David-Wang had received speaker fees from Mundipharma in the past. Dr Neira was an employee of Mundipharma Pte Ltd, Singapore. Ms Teh is an employee of Research Partnership Pte Ltd which conducted the REALISE Asia survey for Mundipharma. Prof Cho is a member of the Editorial Board of Allergy, Asthma & Immunology.Peer reviewedPublisher PD

Effects of loading positions on the activation of trunk and hip muscles during flywheel and dumbbell single-leg Romanian deadlift exercises

Objective: The study compared the activities of the surface electromyography (sEMG) of trunk and hip muscles during single-leg Romanian deadlift (SLRDL) exercises using a flywheel and dumbbell with different loading positions (ipsilateral and contralateral).Method: Twelve active male subjects with at least 2 years of strength training experience (age: 26.7 ± 3.3 years; weight: 73.9 ± 6.2 kg) participated in this study. sEMG in the percentage of maximum voluntary isometric contraction of four SLRDL exercises (ipsilateral and contralateral loading position for dumbbell and flywheel) in a randomized order for superior gluteus maximus (SGM), inferior gluteus maximus (IGM), gluteus medius (GM), biceps femoris (BF), erector spinae (ES), external oblique (EO), and adductor longus (AL) were measured. One-way repeated measure ANOVA with Bonferroni adjustment (statistical significance at 0.05) and the non-clinical magnitude-based decision with a standardized difference were performed for statistical analysis.Results: The overall results demonstrated a very high level of SGM (105.4%–168.6%) and BF (69.6%–122.4%) muscle activities. A significant moderate increase of sEMG signals in GM, IGM, and ES (dominant side) and a large increase in SGM activity during concentric action when the loading position of flywheel SLRDL was changed from ipsilateral to the contralateral side. No significant difference was observed between flywheel and dumbbell SLRDL exercises.Conclusion: Strength coaches may adopt dumbbell or flywheel SLRDL exercises using the contralateral loading position to simultaneously strengthen the hip extensors and trunk stabilizers effectively

Micromechanical Origin of Heat Transfer to Granular Flow

Heat transfer to a granular flow is comprised of two resistances in series: near the wall and within the bulk particle bed, neither of which is well understood due to the lack of experimental probes to separate their respective contribution. Here, we use a frequency modulated photothermal technique to separately quantify the thermal resistances in the near-wall and the bulk bed regions of particles in flowing states. Compared to the stationary state, the flowing leads to a higher near-wall resistance and a lower thermal conductivity of bulk beds. Coupled with discrete element method simulation, we show that the near-wall resistance can be explained by particle diffusion in granular flows.Comment: 14 pages, 5 figures, submitted to Physical Review Letter

Enhancement of Wear and Corrosion Resistance of Beta Titanium Alloy by Laser Technology

The relatively high elastic modulus coupled with the presence of toxic vanadium (V) in Ti6Al4V alloy has long been a concern in orthopaedic applications. To solve the problem, a variety of non-toxic and low modulus beta-titanium (beta-Ti) alloys have been developed. Among the beta-Ti alloy family, the quaternary Ti-Nb-Zr-Ta (TZNT) alloys have received the highest attention as a promising replacement for Ti6Al4V due to their lower elastic modulus and outstanding long term stability against corrosion in biological environments. However, the inferior wear resistance of TNZT is still a problem that must be resolved before commercialising in the orthopaedic market. In this work, a newly-developed laser surface treatment technique was employed to improve the surface properties of Ti-35.3Nb-7.3Zr-5.7Ta alloy. The surface microstructure and composition of the laser-treated TNZT surface were examined by grazing incidence x-ray diffraction (GI-XRD) and x-ray photoelectron spectroscopy (XPS). The wear and corrosion resistance were evaluated by pin-on-plate sliding test and anodic polarisation test in Hanks’ solution. The experimental results were compared with the untreated (or base) TNZT material. The research findings showed that the laser surface treatment technique reported in this work can effectively improve the wear and corrosion resistance of TNZT. The enhancement of such surface properties was due to the formation of a smooth and hard layer on the substrate surface. The laser-formed layer was metallurgically bonded to the substrate, and had no concern of coating delamination or peel-off.Acknowledgments The work described in this paper was supported by research grants from the Hong Kong Polytechnic University (G-YK36 and G-YM75), Hong Kong Special Administration Region, China, and the Queen’s University Belfast (Start-up Research Fund: D8201MAS), United Kingdom

A systematic review and meta-analysis of herbal medicine on chronic obstructive pulmonary diseases

Herbal medicine (HM) as an adjunct therapy has been shown to be promising for the chronic obstructive pulmonary disease (COPD). However, the role of herbs in COPD remains largely unexplored. In this present study, we conducted the systematic review to evaluate the efficacy of herbs in COPD. 176 clinical studies with reporting pulmonary function were retrieved from English and Chinese database. Commonly used herbs for acute exacerbations stage (AECOPD) and stable COPD stage (SCOPD) were identified. A meta-analysis conducted from 15 high quality studies (18 publications) showed that HM as an adjunct therapy had no significant improvement in pulmonary function (FEV1, FEV%, FVC, and FEV1/FVC) compared to conventional medicine. The efficacy of the adjunct HM on improving the arterial blood gas (PaCO2 and PaO 2) for AECOPD and SCOPD remains inconclusive due to the heterogeneity among the studies. However, HM as an adjunct therapy improved clinical symptoms and quality of life (total score, activity score, and impact score of St. George's Respiratory Questionnaire). Studies with large-scale and double-blind randomized controlled trials are required to confirm the role of the adjunct HM in the management of COPD. © 2014 Hai Yong Chen et al.published_or_final_versio

The in vivo Therapeutic Effect of Free Wanderer Powder (逍 遙 散 xiāo yáo sǎn, Xiaoyaosan) on Mice with 4T1 Cell Induced Breast Cancer Model

ABSTRACTIn the present study, we investigated the therapeutic effect of a classical TCM formula, Free Wanderer Powder (逍遙散 xiāo yáo sǎn), in a breast cancer mouse model induced with estrogen-insensitive breast cancer 4T1 cells. Ovariectomized Balb/c mice (6-8 weeks) or sham mice were injected into the fourth mammary fat pad with 4T1 cells in which tumors were palpable 7days after injection. On the eighth day, the mice were divided into 4 groups and tubefed daily with vehicle, Free Wanderer Powder (逍遙散 xiāo yáo sǎn) formula or tamoxifen for 28days. Tumor growth inhibition and the decrease of the average tumor mass were most evident in mice treated with Free Wanderer Powder (逍遙散 xiāo yáo sǎn). Free Wanderer Powder (逍遙散 xiāo yáo sǎn) treatment significantly reduced Bcl-2 and elevated Bax and p53 protein expressions in breast cancer tumor. These results were further confirmed by immunohistochemisty. Tamoxifen could decrease spleen mass and Bcl-2 protein expression, increase the Bax protein expression as well as exert uterotrophic effects by increasing uterus index and inducing the gene expressions in the uterus. Taken together, these results show that Free Wanderer Powder (逍遙散 xiāo yáo sǎn) treatment induced apoptosis at protein level and inhibited the tumor growth in 4T1-induced ovariectomized Balb/c female mice, indicating the possibility of its future use for treatment of estrogen-insensitive breast caner