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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

Single-center study comparing computed tomography colonography with conventional colonoscopy

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World Journal of Gastroenterology 2008年第3期14卷 469-473页

作者： Ian C Roberts-Thomson Graeme R Tucker peter J Hewett peter cheung Ruben A Sebben EE Win Khoo Julie D Marker Wayne K Clapton Department of Gastroenterology The Queen Elizabeth Hospital South Australia Australia Department of Health South Australia Australia Department of Colorectal Surgery The Queen Elizabeth Hospital South Australia Australia Department of Radiology The Queen Elizabeth Hospital South Australia Australia

AIM:To compare the results from computed tomography (CT) colonography with conventional colonoscopy in symptomatic patients referred for colonoscopy. METHODS: The study included 227 adult outpatients, mean age 60 years, with appropriate indications for colonoscopy. CT colonography and colonoscopy were performed on the same day in a metropolitan teaching hospital. Colonoscopists were initially blinded to the results of CT colonography but there was segmental unblinding during the procedure. The primary outcome measures were the sensitivity and specificity of CT colonography for the identification of polyps seen at colonoscopy (i.e. analysis by polyp). Secondary outcome measures included an analysis by patient, extracolonic findings at CT colonography, adverse events with both procedures and patient acceptance and preference. RESULTS: Twenty-five patients (11%) were excluded from the analysis because of incomplete colonoscopy or poor bowel preparation that affected either CT colonography, colonoscopy or both procedures. Polyps and masses (usually cancers) were detected at colonoscopy and CT colonography in 35% and 42% of patients, respectively. Of nine patients with a finaldiagnosis of cancer, eight (89%) were identified by CT colonography as masses (5) or polyps (3). For polyps analyzed according to polyp, the overall sensitivity of CT colonography was 50% (95% CI, 39%-61%) but this increased to 71% (95% CI, 52%-85%) for polyps ≥ 6 mm in size. Similarly, specificity for all polyps was 48% (95% CI, 39%-58%) increasing to 67% (95% CI, 56%-76%) for polyps ≥ 6 mm. Adverse events were uncommon but included one colonic perforation at colonoscopy. Patient acceptance was high for both procedures but preference favoured CT colonography. CONCLUSION: Although CT colonography was more sensitive in this study than in some previous studies, the procedure is not yet sensitive enough for widespread application in symptomatic patients.

关键词： Colorectal polyps Colorectal cancer Computed tomography colonography Colonoscopy

Mini-review on edible mushrooms as source of dietary fiber:Preparation and health benefits

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Food Science and Human Wellness 2013年第3期2卷 162-166页

作者： peter C.K.cheung Food and Nutritional Sciences School of Life SciencesThe Chinese University of Hong KongHong KongChina

Dietary fiber and high-fiber food products have attracted great attention because of their significant health benefits to *** are valuable resources for food,medicine and *** mushroom is considered as a novel source of dietary *** dietary fiber content and composition in edible mushroom vary greatly with its morphological stages including fruit body,mycelium and *** focus of this mini-review is on the preparation of dietary fiber from edible mushroom with emphasis on the sclerotium which has the highest level of non-starch *** possible health benefits of mushroom dietary fiber in relationship with boosting the immune system,anticancer functions as well as the control of blood lipids and glucose levels are also discussed.©2013 Beijing Academy of Food *** and hosting by Elsevier *** rights reserved.

关键词： Dietary fiber Edible mushrooms Health benefits Preparation

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

Enhanced method for the generation of binary Fresnel holograms based on grid-cross downsampling

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Chinese Optics Letters 2011年第12期9卷 15-19页

作者： W.K.cheung peter Tsang T.C.Poon 周常河 Department of Electronic Engineering City University of Hong KongTat Chee AvenueKowloon Bradley Department of Electrical and Computer Engineering Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences

Past research has demonstrated that digital Fresnel holograms can be binarized in a non-iterative manner by downsampling the source image with a grid lattice prior to the hologram generation process. The reconstructed image of a hologram that is binarized with this approach is superior in quality compared with that obtained with direct thresholding, half-toning, and error diffusion. Despite the success, the downsampling mechanism results in a prominent texture of regularly spaced voids in the shaded regions. To alleviate this problem, an enhanced non-iterative method for the generation of binary Fresnel holograms is presented. Our method is based on a multi-direction line-sampling formed by a combined grid and cross lattice, which is capable of preserving a more solid texture in the shaded regions and enhancing the visual quality of the reconstructed image. Computer simulations and optical reconstructions are shown to demonstrate the effectiveness of our proposed technique.

关键词： Computer simulation Lithography Textures

Fast numerical generation and hybrid encryption of a computer-generated Fresnel holographic video sequence

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Chinese Optics Letters 2013年第2期11卷 27-31页

作者： peter Tsang K.W.-K. cheung T.-C. Poon Department of Electronic Engineering City University of Hong KongTat Chee AvenueKowloon Bradley Department of Electrical and Computer Engineering Virginia TechUSA Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences

Research demonstrates that a Fresnel hologram can be generated and simultaneously encrypted numerically based on a secret symmetric key formed by the maximal length sequence （M-sequence）. The method can be directly extended to encrypt a video holographic clip in a frame-by-frame manner. However, given the limited combination of signals in the family of M-sequence, hacking the secret key through trial and error can be time consuming but not difficult. In this letter, we propose a method that is difficult to crack with brute force for enerypting a holographic video sequence. An M-sequence is first randomly assigned to enerypt each frame of the holographic video signal. Subsequently, the index of the selected M-sequence, which is necessary to decrypt the hologram~ is encrypted with the RSA algorithm before transmitting to the receiving end. At the receiving end, the decoder is provided with a private key to recover the index for each frame, and the corresDonding M-se（mence is used to decrvDt the encoded hologram.

关键词： Access control Computer generated holography Cryptography Personal computing Video recording

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

System Integration in Radiation Oncology Through Networking

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临床医学工程 1998年第3期 107-110页

作者： K.Y.cheung Ricky Chau peter Choi Departmen of Clinical Oncology Hong Kong Prince of Wales Hospital

This paper presents the basic system design and our initial experience on the operation and performance of a fully integrated radiotherapy treatment planning, treatment delivery and patient management network system at the Prince of Wales Hostpital, Hong Kong, The aim of the project is to establish a suitable tool for easy and reliable implementation of routine conformal radiotherapy and to improve the effciency and quality of radiotherapy service through system integration

关键词： In System Integration in Radiation Oncology Through Networking 加心比切

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虎奶菇菌丝体细胞壁成分分析及多糖结构表征

食品与发酵工业 2020年第6期46卷 41-48页

作者：葛梦蝶代安然杨崇婧刘京京 cheung Chi Keung peter 陈磊江南大学生物工程学院糖化学与生物技术重点实验室江苏无锡214122 香港中文大学生命科学学院中国香港999077

该文以液态发酵的虎奶菇(Pleurotus tuber-regium,PTR)菌丝体为原料,对PTR菌丝体细胞壁(PTR-MCW)的组分进行分析,并阐明细胞壁骨架结构。采用不同提取强度的溶剂分离MCW的可溶性成分,对各组分进行含量测定、化学成分分析及基本结构表征... 详细信息

该文以液态发酵的虎奶菇(Pleurotus tuber-regium,PTR)菌丝体为原料,对PTR菌丝体细胞壁(PTR-MCW)的组分进行分析,并阐明细胞壁骨架结构。采用不同提取强度的溶剂分离MCW的可溶性成分,对各组分进行含量测定、化学成分分析及基本结构表征。结果表明,PTR-MCW主要由4部分组成:热水提多糖和蛋白质复合物的外层,常温碱提的杂多糖部分,热碱提的高度支化杂多糖部分和碱不溶性多糖-几丁质复合物部分,这4种组分在PTR-MCW中的比例为2.06∶22.06∶46.97∶18.95。占主要组分的热碱提多糖经纯化后得到纯多糖MHA-I,单糖组成和甲基化分析表明其糖苷键类型包括T-木糖、T-鼠李糖、T-葡萄糖、1,3-葡萄糖、1,6-葡萄糖、1,4-葡萄糖、1,3,6-葡萄糖、1,4,6-葡萄糖、1,3,6-甘露糖,摩尔比为2.01∶1.00∶27.64∶8.19∶38.22∶20.88∶14.38∶6.98∶3.22,该多糖的分支度(degree of branching,DB)为0.45,FT-IR分析鉴定MHA-I中主要为β-糖苷键。SEC-MALLS分析表明,超支化杂多糖MHA-I的分子量为4.502×10^4 g/mol,回转半径为33.2 nm。电镜结果显示,MHA-I为具有超支化结构的多糖,在干燥的粉末状态下呈现准球形结构。该研究成果为虎奶菇多糖的开发及活性研究提供一定的理论依据。

关键词：虎奶菇菌丝体细胞壁多糖结构鉴定