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Calcium sulfate, an injectable and biodegradable bone‐void filler, is widely used in orthopedic surgery. Based on clinical experience, bone‐defect substitutes can also serve as vehicles for the delivery of drugs, for example, antibiotics, to prevent or to treat infections such as osteomyelitis. However, antibiotic additions change the characteristics of calcium sulfate cement. Moreover, high‐dose antibiotics may also be toxic to bony tissues. Accordingly, cefazolin at varying weight ratios was added to calcium sulfate samples and characterized in vitro. The results revealed that cefazolin changed the hydration reaction and prolonged the initial setting times of calcium sulfate bone cement. For the crystalline structure identification, X‐ray diffractometer revealed that cefazolin additive resulted in the decrease of peak intensity corresponding to calcium sulfate dihydrate which implying incomplete phase conversion of calcium sulfate hemihydrate. In addition, scanning electron microscope inspection exhibited cefazolin changed the morphology and size of the crystals greatly. A relatively higher amount of cefazolin additive caused a faster degradation and a lower compressive strength of calcium sulfate compared with those of uploaded samples. Furthermore, the extract of cefazolin‐impregnated calcium sulfate impaired cell viability, and caused the death of osteoblast‐like cells. The results of this study revealed that the cefazolin additives prolonged setting time, impaired mechanical strength, accelerated degradation, and caused cytotoxicity of the calcium sulfate bone‐void filler. The aforementioned concerns should be considered during intra‐operative applications. [ABSTRACT FROM AUTHOR]

近年來快速發展的新聞網站衍生使用者對於資訊查詢的強烈需求，而目前許多新聞網站(例如：Google News)可以自動針對網際網路的新聞進行新聞事件的自動分類，以提供讀者相���新聞事件的聚集資訊，也提供以關鍵字進行新聞查詢的功能，但是卻無法提供整 個相關新聞事件發展脈絡的查詢及依據主題相關之新聞地圖的呈現機制。本研究利用Google News可以自動將新聞事件分類的特性，進一步利用改良式霍普菲爾類神經網路(Modified Hopfield Neural Networks, MHNN)自動歸納產生新聞查詢語句知識本體(ontology)，並依據所產生之新聞查詢語句知識本體，提出了一個可以依據使用者感興趣新聞類別來做新 聞事件的擴展查詢(query expansion)機制，以強化新聞搜尋的效能。此外，藉由主題地圖(topic maps)之方式提供有別於傳統新聞呈現方式給使用者瀏覽閱讀，可以將新聞查詢結果依據時間標記及主題關聯呈現，讓使用者能更清楚地掌握整個新聞主題的發 展脈絡。With the rapid development of the computer and Internet techniques, the Internet appears some news aggregator sites containing a large number of news articles, thus leading to advanced information retrieval requirements. Particularly, some news sites, such as Google news, provide automatically classified news information and keyword based search mechanism to readers for retrieving user-interested news events. However, most news sites do not provide currently to retrieve the developing clues of a news event and display the search results by the topic map with visualization user interface. Therefore, this study presents a novel news search engine with automatic user query expansion mechanism and a friendly topic map user interface based on the automatic generation scheme of news ontology constructed by Modified Hopfield Neural Networks. The experimental results indicate that the proposed query expansion mechanism based on the generated news ontology can efficiently help users to retrieve the user-interested news events. Meanwhile, the providing topic map of news events ranked by time stamp also provides benefits in terms of observing the developing context of a news event.頁次：19-41