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COMPARISON OF POLYSACCHARIDES ISOLATED FROM THE MYCELIA OF A CULTIVATED STRAIN OF PORIA COCOS GROWN IN DIFFERENT LIQUID CULTURE MEDIA

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chinese Journal of Polymer Science 2003年第4期21卷 465-472页

作者： peter chi keung cheung 张俐娜 Department of Biology The Chinese University of Hong Kong Hong Kong China Department of Chemistry Wuhan University Wuhan 430072 China

Mycelium of a cultivated strain of Poria cocos was grown by submerged fermentation in a liquid mediumcontaining corn steep liquor with orbital shaking. Six polysaccharides coded as ac-PCM1, ac-PCM2, ac-PCM3-Ⅰ andⅡ, ac-PCM4-Ⅰand Ⅱ were isolated from the myelium by extracting with 0.9% NaCl aqueous solution, hot water, 0.5 mol/L NaOHaqueous solution and 88% formic acid. Exo-polysaccharide was obtained from the culture medium and coded as *** monosaccharide composition and molecular weights of these polysaccharides were characterized by using infraredspectroscopy, gas chromaography, elemental analysis, ^(13)C-NMR, viscometry and light scattering. The results indicated thatac-PCM0, ac-PCM1 and ac-PCM2 are heteropolysaccharides containing glucose, galactose, mannose and fucose, and ac-PCM3-Ⅰ and ac-PCM3-Ⅱ mainly consist of D-glucose. The content of the glucose in the polysaccharides increased with theisolation progress. Remarkably, α-glucan and β-glucan coexisted in the extract by NaOH aqueous solution (ac-PCM3), andcould be separated by chemical methods. The protein in the ac-PCM polysaccharides cultured from the medium containingcorn steep liquor was higher than that in the ab-PCM from the medium with bran extract. Therefore, the polysaccharidesfrom Poria cocos mycelia cultured in different media have different chemical composition, molecular weights and conformations.

关键词： Poria cocos mycelium Culture medium Polysaccharide Monosaccharide composition Molecular weight

Application of naturalβ-glucans as biocompatible functional nanomaterials

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Food Science and Human Wellness 2019年第4期8卷 315-319页

作者： Xiaojie Li peter chi keung cheung Food and Nutritional Sciences School of Life SciencesThe Chinese University of Hong KongHong KongChina

Naturally-occurringβ-glucans are mostly investigated for their antitumor activity and immunomodulatory *** have been widely regarded as a natural source for functional foods and ***,the physico-chemically stable and biocompatible properties ofβ-glucans are rarely explored as a coating material for nanomaterials to overcome the problems of aggregation and *** article reviews on the exploration ofβ-glucans,in particular those derived from mushrooms,as a natural coating material to modify the surface properties of bioactive substances as a relatively simple and cost-effective strategy to produce stable and biocompatible nanohybrids used for biopharmaceutical *** is envisaged that suchβ-glucan-based coating method will provide new opportunities to design biocompatible functional nanomaterials for wider clinical applications.

关键词： β-Glucans Biocompatibility Biopharmaceuticals Nanohybrids

Magnetic activity of the spotted dwarf AP149 in the α Persei open cluster

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Research in Astronomy and Astrophysics 2010年第3期10卷 253-265页

作者： Xiang-Song Fang Sheng-Hong Gu Sze-Leung cheung Ho-keung Hui chi-Tai Kwok Kam-cheung Leung National Astronomical Observatories / Yunnan Observatory Chinese Academy of Sciences Kunming 650011 China Graduate University of chinese Academy of Sciences Beijing 100049 China Ho Koon Nature Education cum Astronomical Centre Sik Sik Yuen Hong Kong China Hong Kong Astronomical Society Hong Kong China

The simultaneous photometric and spectroscopic observations of the spotted G dwarf AP149 in the young open cluster α Persei are analyzed here. We reconstruct the observed light curves with a two-starspot model by means of a light curve modeling technique, and find that the active regions shift oppositely along longitude on a time scale of one day. Combining with the observational data obtained by other groups, we discuss the evolution of spotted regions in the photosphere, and find that its starspots evolve not only on a short time scale but also on a long time scale. The pure chromospheric emissions for Ca IIHK and Hβ lines are derived by using the spectral subtraction technique. The variation of Ca IIHK lines＇ excess emission is spatially correlated to the starspot regions. There is no clear rotational modulation for the Hβ line＇s excess emission, probably due to the contamination of prominence emission.

关键词： stars: activity -- stars: late-type -- stars: spots -- stars: individual AP149

A newly discovered active contact binary in the field of NGC 1348

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Research in Astronomy and Astrophysics 2012年第1期12卷 93-103页

作者： Xiang-Song Fang Sheng-Hong Gu Ho-keung Hui chi-Tai Kwok Bill Yeung Kam-cheung Leung National Astronomical Observatories / Yunnan Observatory Chinese Academy of SciencesKunming 650011 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming 650011 China Graduate University of chinese Academy of Sciences Beijing 100049 China Hokoon Nature Education cum Astronomical Centre Sik Sik-Yuen Hong Kong China Hong Kong Astronomical Society Hong Kong China

We present a CCD photometry study of a newly discovered active eclipsing binary in the field of open cluster NGC 1348 based on the first time-series photometric observation. From the minimum times, we determined an orbital period of P = 0.691363 d. Among our datasets, the BV（.RI）c light curves obtained in November 2008 were analyzed using the Wilson-Devinney light curve modeling tech- nique. Because of the uncertainty of the membership of this binary in open cluster NGC 1348, we have analyzed the photometric data in two cases with different primary effective temperatures： Case A （T1 = 7750K） and Case B （T1 = 5250K）. Our anal- yses reveal that, for Case A, it is a deep （f 〉 70%）, very low mass ratio （q - 0.096） binary system, indicating that it is now in the late evolution stage of a contact binary; while for Case B, it is a red system with extraordinarily long orbital period with respect to the period-color relation for normal contact binaries, which suggests that this binary has evolved off the main sequence. The well known O＇Connell effect （e.g., AB 0.03 mag） was found in the dataset obtained in November 2008, which could be due to the existence of starspots on the components, therefore the corresponding spot properties （for Case A： hot spot; for Case B： dark spot） were determined using the Wilson-Devinney code. With the purpose of analyzing the dark spot activity for Case B, we compared the light curves derived in different observing runs, and found that a slight change appeared from November to December, 2008, which indicates the evolution of spot activity on at least one component over a time scale of about one month.

关键词： stars: binaries: close -- stars: binaries: eclipsing -- stars: spots

The refined physical parameters of transiting exoplanet system HAT-P-24

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Research in Astronomy and Astrophysics 2013年第5期13卷 593-603页

作者： Xiao-Bin Wang Sheng-Hong Gu Andrew Collier Cameron Hong-Bo Tan Ho-keung Hui chi-Tai Kwok Bill Yeung Kam-cheung National Astronomical Observatories/Yunnan Observatory Chinese Academy of Sciences Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences School of Physics and Astronomy University of St Andrews North Haugh St Andrews Fife KY16 9SS UK University of chinese Academy of Sciences Hokoon Nature Education cum Astronomical Centre Sik Sik Yuen Hong Kong Astronomical Society

The transiting exoplanet system HAT-P-24 was observed by using CCD cameras at Yunnan Observatory and Hokoon Astronomical Centre, china in 2010 and 2012. In order to enhance the signal to noise ratio of transit events, the observed data are corrected for systematic errors according to Collier Cameron et al.＇s coarse de- correlation and Tamuz et al.＇s SYSREM algorithms. Three new complete transit light curves are analyzed by means of the Markov chain Monte Carlo technique, and the new physical parameters of the system are derived. They are consistent with the old ones from the discovered paper except for a new larger radius Rp = 1.364 Rj of HAT- P-24b, which confirms its inflated nature. By combining the five available epochs of mid-transit derived from complete transit light curves, the orbital period of HAT-P- 24b is refined to P = 3.3552479 d and no obvious transit timing variation signal can be found from these five transit events during 2010-2012.

关键词： exoplanet system -- transit -- individual: HAT-P-24

Long-term transit timing monitoring and homogenous study of WASP-32

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Research in Astronomy and Astrophysics 2015年第1期15卷 117-126页

作者： Lei-Lei Sun Sheng-Hong Gu Xiao-Bin Wang Andrew Collier Cameron Dong-Tao Cao Yi-Bo Wang Yue Xiang Ho-keung Hui chi-Tai Kwok Bill Yeung Kam-cheung Leung Yunnan Observatories Chinese Academy of Sciences Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences University of chinese Academy of Sciences School of Physics and Astronomy University of St Andrews North Haugh St Andrews Fife KY16 9SS UK Ho Koon Nature Education cum Astronomical Centre Hong Kong Astronomical Society

We report new photometric observations of the transiting exoplanetary system WASP-32 made by using CCD cameras at Yunnan Observatories and Ho Koon Nature Education cum Astronomical Centre, china from 2010 to 2012. Following our usual procedure, the observed data are corrected for systematic errors according to the coarse decorrelation and SYSREM algorithms so as to enhance the signal of the transit events. Combined with radial velocity data presented in the literature, our newly observed data and earlier photometric data in the literature are simultaneously analyzed to derive the physical parameters describing the system by employing the Markov chain Monte Carlo technique. The derived parameters are consistent with the result published in the original paper about WASP-32b, but the uncertainties of the new parameters are smaller than those in the original paper. Moreover, our modeling result supports a circular orbit for WASP-32b. Through the analysis of all available mid-transit times, we have refined the orbital period of WASP-32b; no evident transit timing variation is found in these transit events.

关键词： techniques: photometric transiting exoplanetary system individual: WASP-32

Risk of cardiovascular thrombotic events after surgical castration versus gonadotropin-releasing hormone agonists in chinese men with prostate cancer

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Asian Journal of Andrology 2015年第3期17卷 493-496页

作者： Jeremy YC Teoh Samson YS Chan peter KF chiu Darren MC Poon Ho-Yuen cheung Simon SM Hou chi-Fai Ng Department of Surgery Division of Urology Prince of Wales Hospital The Chinese University of Hong Kong Shatin Hong Kong China Department of Clinical Oncology Prince of Wales Hospital The Chinese University of Hong Kong Shatin Hong Kong China Department of Surgery Division of Urology North District Hospital Hong Kong China

We investigated the cardiovascular thrombotic risk after surgical castration （SC） versus genadotmpin-releasing hormone agonists （GnRHa） in chinese men with prostate cancer. All chinese prostate cancer patients who were treated with SC or GnRHa from year 2000 to 2009 were reviewed and compared. The primary outcome was any new-onset of cardiovascular thrombotic events after SC or GnRHa, which was defined as any event of acute myocardial infarction or ischemic stroke. The risk of new-onset cardiovascular thrombotic event was compared between the SC group and the GnRHa group using Kaplan-Meier method. Multivariate Cox regression analysis was performed to adjust for other potential confounding factors. A total of 684 chinese patients was included in our study, including 387 patients in the SC group and 297 patients in the GnRHa group. The mean age in the SC group （75.3 ~ 7.5 years） was significantly higher than the GnRHa group （71.8 ~ 8.3 years）（P 〈 0.001）. There was increased risk of new cardiovascular thrombotic events in the SC group when compared to the GnRHa group upon Kaplan-Meier analysis （P= 0.014）. Upon multivariate Cox regression analysis, age （hazard ratio [HR] 1.072, 95% confidence interval [CI] 1.04-1.11, P 〈 0.001）, hyperlipidemia （HR 2.455, 95% Cl 1.53-3.93, P 〈 0.001）, and SC （HR 1.648, 95% CI 1.05-2.59, P = 0.031） were significant risk factors of cardiovascular thrombotic events. In conclusion, SC was associated with increased risk of cardiovascular thrombotic events when compared to GnRHa. This is an important aspect to consider while deciding on the method of androgen deprivation therapy, especially in elderly men with known history of hyperlipidemia.

关键词： androgen deprivation therapy chinese population cardiovascular events myocardial infarction prostate cancer stroke

Time trend and characteristics of prostate cancer diagnosed in Hong Kong(china)in the past two decades

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Asian Journal of Andrology 2019年第1期21卷 104-106页

作者： Ho-Fai Wong chi-Hang Yee Jeremy YC Teoh Samson YS Chan peter KF chiu Ho-Yuen cheung Simon SM Hou chi Fai Ng S H.Ho Urology Centre Department of SurgeryThe Chinese University of Hong KongHong KongChina

Dear Editor, Prostate cancer is an important disease worldwide)In 2015 it was the third most common cancer diagnosed in male in Hong Kong (china) and the incidence of prostate cancer has been rising in the past 15 years. Meanwhile,with increasing public awareness,health education, presentation,and detection of prostate cancer maybe ***, we would like to review how the epidemiology of prostate cancer in Hong Kong (china)had changed in the past two decades.

关键词： prostate cancer Time trend

Echocardiographic mapping of left ventricular resynchronization during cardiac resynchronization therapy procedures

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chinese Medical Journal 2010年第13期123卷 1645-1651页

作者： CHAN Ngai-yin CHOY chi-chung cheung Kar-chun LAU Chun-leung LO Ying-keung CHU Pui-shan YUEN Ho-chuen LAU Suet-ting CHOI Yuen-choi Department of Medicine & Geriatrics Princess Margaret Hospital 2-10 Princess Margaret Hospital Road Lai Chi Kok Kowloon Hong Kong China

Background Cardiac resynchronization therapy （CRT） is an effective electrical therapy for patients with moderate to severe heart failure and cardiac dyssynchrony. This study aimed to investigate the degree of acute left ventricular （LV） resynchronization with biventricular pacing （BVP） at different LV sites and to examine the feasibility of performing transthoracic echocardiography （TTE） to quantify acute LV resynchronization during CRT procedure. Methods Fourteen patients with NYHA Class Ⅲ-Ⅳ heart failure, LV ejection fraction 〈35%, QRS duration 〉120 ms and septal-lateral delay （SLD）〉60 ms on tissue Doppler imaging （TDI）, underwent CRT implant. TDI was obtained from three apical views during BVP at each accessible LV site and SLD during BVP was derived. Synchronicity gain index （Sg） by SLD was defined as （I＋（SLD at baseline - SLD at BVP）/SLD at baseline）. Results Seventy-two sites were studied. Positive resynchronization （R＋, Sg〉1） was found in 42 （58%） sites. R＋ was more likely in posterior or lateral than anterior LV sites （66% vs. 36%, P 〈0.001）. Concordance of empirical LV lead implantation sites and sites with R＋ was 50% （7/14）. Conclusions The degree of acute LV resynchronizaUon by BVP depends on LV lead location and empirical implantation of LV lead results in only 50% concordance with R＋. Performing l-rE during CRT implantation is feasible to identify LV sites with positive resynchronization.

关键词： echocardiography cardiac resynchronization therapy heart failure left ventricular lead device implantation optimization