7,250 research outputs found
Arsenic Carcinogenesis in the Skin
No full textChronic arsenic poisoning is a world public health issue. Long-term exposure to inorganic arsenic (As) from drinking water has been documented to induce cancers in lung, urinary bladder, kidney, liver and skin in a dose-response relationship. Oxidative stress, chromosomal abnormality and altered growth factors are possible modes of action in arsenic carcinogenesis. Arsenic tends to accumulate in the skin. Skin hyperpigmentation and hyperkeratosis have long been known to be the hallmark signs of chronic As exposure. There are significant associations between these dermatological lesions and risk of skin cancer. The most common arsenic-induced skin cancers are Bowen's disease ( carcinoma in situ), basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Arsenic-induced Bowen's disease (As-BD ) is able to transform into invasive BCC and SCC. Individuals with As-BD are considered for more aggressive cancer screening in the lung and urinary bladder. As-BD provides an excellent model for studying the early stages of chemical carcinogenesis in human beings. Arsenic exposure is associated with G2/M cell cycle arrest and DNA aneuploidy in both cultured keratinocytes and As -BD lesions. These cellular abnormalities relate to the p53 dysfunction induced by arsenic. The characteristic clinical figures of arsenic- induced skin cancer are: (i) occurrence on sun-protected areas of the body ; (ii) multiple and recrudescent lesions. Both As and UVB are able to induce skin cancer. Arsenic treatment enhances the cytotoxicity, mutagenicity and clastogenicity of UV in mammalian cells. Both As and UVB induce apoptosis in keratinocytes by caspase-9 and caspase-8 signaling, respectively. Combined UVB and As treatments resulted in the antiproliferative and proapoptotic effects by stimulating both caspase pathways in the keratinocytes. UVB irradiation inhibited mutant p53 and ki -67 expression, as well as increased in the number of apoptotic cells in As- BD lesions which resulted in an inhibitory effect on proliferation. As -UVB interaction provides a reasonable explanation for the rare occurrences of arsenical cancer in the sun-exposed skin. The multiple and recurrent skin lesions are associated with cellular immune dysfunction in chronic arsenism. A decrease in peripheral CD4+ cells was noticed in the inhabitants of arsenic exposure areas. There was a decrease in the number of Langerhans cells in As-BD lesion which results in an impaired immune function on the lesional sites. Since CD4+ cells are the target cell affected by As, the interaction between CD4+ cells and epidermal keratinocytes under As affection might be closely linked to the pathogenesis of multiple occurrence of arsenic -induced skin cancer. In this review, we provide and discuss the pathomechanisms of arsenic skin cancer and the relationship to its characteristic figures. Such information is critical for understanding the molecular mechanism for arsenic carcinogenesis in other internal organs
Indeterminate void: reconstituting the urban hinge for Wan Chai.
No full textYuen Ching Yin."Architecture Department, Chinese University of Hong Kong, Master of Architecture Programme 2007-2008, design report."Includes bibliographical references.Chapter 1 --- AbstractChapter 2 --- Research on Phenomena within and outside ArchitectureChapter 2.1 --- VoidnessChapter 2.2 --- IndeterminacyChapter 2.3 --- Japanese HaikuChapter 2.4 --- "Spatial Continuum - Dongtongchi, Ancestral Hall in Jiangxi"Chapter 2.5 --- Event Space - Dongtongchi and Dafen MuseumChapter 2.6 --- Merging with Everyday Life - Kanazawa MuseumChapter 2.7 --- Temporal MarginChapter 2.8 --- HingeChapter 2.9 --- Edge ConditionChapter 2.10 --- Hinge as a strategy of ReprogrammingChapter 2.11 --- Dissolving EdgesChapter 3 --- Research SummaryChapter 4 --- Design StrategyChapter 5 --- Contextual Experiment - Southorn Playground in Wan Chai as a Testing GroundChapter 5.1 --- Site SurveyChapter 5.2 --- Design ConstraintsChapter 5.3 --- Design SchemeChapter 5.4 --- Design Documentatio
Learning Mandarin as first language: The speech production of Mandarin plosive consonants by bilingual Sino-KDMs / Chai Chee Wah
No full textThe Sino-KDMs are the descendants of Sabah's ethnic minority, the aborigines who intermarried with the Chinese. They make up majority of Chinese primary school nowadays and learn Mandarin as a first language without discrimination compared to the Mandarin native speaker. Phonologically, short-lag and long-lag VOT plosive are distinct phonemes in Mandarin, while both are realizations of voiceless plosive in Malay. All measurements were based on second syllable extracted from manuscript reading recordings. Results revealed that the Sino-KDMs displayed three different patterns of plosive consonants: 1. Commonly confused between aspirated and unaspirated consonants from a set of place of articulation; 2. Frequently produced [x] in aspirated plosive consonants; 3. Bilabial plosive consonants [p] and [ph] are the most form of errors
sj-doc-3-chl-10.1177_17475198211052011 – Supplemental material for A new coumarin from pericarps of Zanthoxylum bungeanum Maxim
No full textSupplemental material, sj-doc-3-chl-10.1177_17475198211052011 for A new coumarin from pericarps of Zanthoxylum bungeanum Maxim by Tian Chai, Wen-Han Zhang, Hui Jiao and Yin Qiang in Journal of Chemical Research</p
sj-docx-1-chl-10.1177_17475198211052011 – Supplemental material for A new coumarin from pericarps of Zanthoxylum bungeanum Maxim
No full textSupplemental material, sj-docx-1-chl-10.1177_17475198211052011 for A new coumarin from pericarps of Zanthoxylum bungeanum Maxim by Tian Chai, Wen-Han Zhang, Hui Jiao and Yin Qiang in Journal of Chemical Research</p
sj-doc-2-chl-10.1177_17475198211052011 – Supplemental material for A new coumarin from pericarps of Zanthoxylum bungeanum Maxim
No full textSupplemental material, sj-doc-2-chl-10.1177_17475198211052011 for A new coumarin from pericarps of Zanthoxylum bungeanum Maxim by Tian Chai, Wen-Han Zhang, Hui Jiao and Yin Qiang in Journal of Chemical Research</p
sj-doc-1-chl-10.1177_17475198211052011 – Supplemental material for A new coumarin from pericarps of Zanthoxylum bungeanum Maxim
No full textSupplemental material, sj-doc-1-chl-10.1177_17475198211052011 for A new coumarin from pericarps of Zanthoxylum bungeanum Maxim by Tian Chai, Wen-Han Zhang, Hui Jiao and Yin Qiang in Journal of Chemical Research</p
Vertical Export Flux of Particulate Organic Carbon from the Water Column off Southwestern Taiwan
No full text本研究利用海研一號3個航次在台灣西南海域兩測站採集樣水，進行溶解相和顆粒相釷-234分析。經由不同採樣梯次，本研究亦量測了顆粒有機碳濃度、營養鹽以及其他水文化學參數的垂直剖面。經由量測水體中不足釷-234顯示本研究海域受到快速的清除以及顆粒移除作用影響。
由釷-234/鈾-238不平衡計算結果顯示台灣西南海域各航次釷-234垂直輸出通量由近表水的100 dpm/m2/d隨深度遞增；在1999年的B2及HT站釷-234垂直輸出通量分別可達5800和8200 dpm/m2/d，2003及2004年的HT站釷-234輸出通量明顯比1999年要來的低，這兩次的通量分別為5400和2800 dpm/m2/d；而在1999年這個航次明顯受到陸源輸入的影響，HT站釷-234垂直輸出通量隨深度的增加率比B2站高出許多。
利用釷-234/鈾-238不平衡和顆粒有機碳及釷-234比值的關係，本研究估算出台灣西南海域顆粒有機碳輸出通量（POC Flux）。在光透層底部（50m左右），HT-1和HT-2兩站分別出現輸出通量的極大值（20 mmole C/L/d，98 mmole C/L/d），值得注意的是顆粒有機碳輸出通量的極大值通常會伴隨著亞硝酸鹽極大值的出現；另外，B2站以及2003年HT測站在250m處也有著極大值的出現（28 mmole C/L/d，109 mmole C/L/d），吾人研判有可能是側向傳輸所造成。台灣西南海域顆粒有機碳垂直輸出通量在HT測站可達約200 mmole C/m2/d，明顯比B2測站的75 mmole C/m2/d來的大，吾人研判可能為B2測站離岸較遠，受到陸源輸入的影響較少所導致。此外，若將同一測站不同採樣時間的HT-1及HT-2做比較，可以發現在下午2點採樣的HT-2站顆粒有機碳輸出通量有較高的極大值和遞減率，此現象可能是因為上層水體中顆粒有機碳產量和呼吸率的日變化所造成的結果。目 錄
頁數
摘要…………………………………………………………………………………….Ⅰ
圖目錄………………………………………………………………………………....Ⅱ
表目錄…………………………………………………………………………………III
第一章 緒論……………………………………………………………………...........1
1.1 研究目的與動機……………………………………………………………......1
1.2 前人研究之回顧……………………………………………………………......3
1.3 顆粒態有機碳垂直輸出通量（POC Flux）的重要性………….…………….7
1.4 釷-234/鈾-238不平衡與POC Flux……………………………….……….....10
1.5 研究區域簡介…………………………………………………………………12
第二章 研究方法…………………………………………………………………….14
2.1 顆粒有機碳（POC）之採樣與前處理……………………….……………...14
2.2 顆粒有機碳之分析方法………………………………………………………14
2.3 釷-234二相之分析方法與活度計算………………………………………...15
2.3.1 溶解相釷-234活度分析方法…………………………………............16
2.3.2 顆粒相釷-234活度分析方法…………………………………………17
第三章 結果與討論………………………………………………………………….18
3.1 研究區域之水文特性…………………………………………………………18
3.2 水體中釷-234活度之垂直變化………………………...…………………….22
3.3 水體中顆粒態有機碳之垂直變化…………………………………………….27
3.4 台灣西南海域釷-234對顆粒之親和力……………………………………….31
3.4.1 總懸浮顆粒物質濃度【TSM】…………………………………………31
3.4.2 釷-234的分佈係數【Kd】………………………………………..........35
3.5 台灣西南海域釷-234之清除現象……………………………........................39
3.5.1 一維不可逆清除模式................................................................................39
3.5.2 水體中釷-234清除速率（J）與移除速率（P）之探討………………41
3.5.2.1 釷-234的清除速率與通量……………………………………..41
3.5.2.2 釷-234的移除速率與通量……………………………………..43
3.5.3 水體中釷-234的滯留時間……………………………………………...47
3.6 台灣西南海域顆粒有機碳垂直輸出通量（POC Flux）…………………....49
3.6.1 如何計算出POC Flux？…………………………………………….….49
3.6.2 ratio對模式的影響………………………………………………50
3.6.3 西南海域POC Flux……………………………………………………..54
第四章 結論……………………..…………………………………………………...58
4.1 結論………………………………………………………………………..58
4.2 未來研究方向……………………………………………………………..59
參考文獻……………………………………………………………………………...60
附錄Ⅰ、各航次水體垂直剖面之分析數據…………………………...…….…..….69
附錄Ⅱ、本研究各航次釷-234滯留時間…………………………………...………7
Bryan, Fong Yin atlet terbaik MASUM
No full textATLET terjun lelaki negara, Bryan Nickson Lomas, 23, dan atlet wushu wanita, Chai Fong Yin, 25, dinobatkan sebagai Olahragawan dan Olahragawati Majlis Sukan Universiti Malaysia (MASUM) dalam satu majlis gilang gemilang Anugerah Sukan MASUM 2010 di Kota Kinabalu, Sabah pada 9 April lalu
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