PTT Corpus: Construction and Applications

近年來,語料庫為本與語料庫驅動之研究愈來愈受到關注與重視。 在台灣華語中,中央研究院平衡語料庫 (Chen et al., 1996) 以及中文十 億詞語料庫 (Huang et al., 2005) 為當今兩個最被廣泛使用的語料庫。然 而,這些語料庫並不是完全沒有限制。在語料的部份,這些語料庫大 多已經停止更新或尚未更新,也就是說,這些資料庫已經無法完全即 時反應當代台灣華語的使用狀況。對於眾多研究者來說,在蒐集新興 語料上更產生了一定的程度的難度與不便性。正因如此,本篇論文以 PTT(批踢踢)作為資料來源,試圖建立「批踢踢語料庫」— 一個具 有自動蒐集、更新、分析及後處理的動態語料庫。除此之外,該語料 庫亦會提供一個友善且便利的網路平台,提供研究者作使用。在批踢 踢語料庫中,語料的斷詞是透過 Jseg — 一個利用中央研究院平衡語 料為訓練基礎之中文斷詞器 — 所達成。而在詞性標註方面,則是採 用 Brill Tagger (Brill, 1992) 所使用的演算法,且以中文句結構樹資料庫 (Chen et al., 1999) 中約莫一萬中文句作為訓練的語料。批踢踢語料庫提 供了網路介面以供研究者使用,並包含許多根據批踢踢語料所發展出 來的應用,其中包括基本的詞語索引器 (Concordancer) 以及搭配詞抽 取器 (Collocation extractor),以及其他諸如表情符號偵測器 (Emoticon detector) 與情緒極性分類器 (Sentiment polarity classifier) 等等之應用。 最後,本研究之希望在批踢踢語料庫的建置後,在現代台灣華語中能 夠針對新興語料的部分作補充與更新,並且提供實質的語料庫工具, 以簡化資料蒐集上的繁瑣及能有系統地分析語料,使得研究者能更加 專注在語料本身的分析與發展。In recent years, corpus-based and corpus-driven studies are getting considerable attentions. In Taiwan Mandarin, two of the most widely used corpora are Academia Sinica Balanced Corpus (Chen et al., 1996) and Chinese Gigawords (Huang et al., 2005). However, both of the corpora have some limitations on the source of the data, and they have not updated for some time, which makes it difficult to collect more recent examples of language uses. Therefore, the aim of this thesis attempts to establish a dynamic corpus, PTT Corpus, which can automatically collect, update and process data from PTT (批踢 踢), and provide the applications with a user-friendly interface for researchers. Corpora are segmented with Jseg, a Chinese segmentator trained with data from Sinica Corpus, and part-of-speech (POS) tagged by Brill Tagger (Brill, 1992), a POS tagger trained with data trained on the 9999 sentences in the Sinica Treebank (Chen et al., 1999). PTT Corpus provides a web interface with several applications, including Concordancer, Collocation extractor, Emoticon Detector, etc. To conclude, establishing PTT Corpus may be of importance in enriching the source of modern corpora, providing useful corpus tools, simplifying the analysis of recent language uses and changes in linguists in Taiwan Mandarin

Observing Features of PTT Neologisms: A Corpus-driven Study with N-gram Model

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Shikonin Induces Apoptosis, Necrosis, and Premature Senescence of Human A549 Lung Cancer Cells through Upregulation of p53 Expression

Shikonin, a natural naphthoquinone pigment isolated from Lithospermum erythrorhizon, has been reported to suppress growth of various cancer cells. This study was aimed to investigate whether this chemical could also inhibit cell growth of lung cancer cells and, if so, works via what molecular mechanism. To fulfill this, A549 lung cancer cells were treated with shikonin and then subjected to microscopic, biochemical, flow cytometric, and molecular analyses. Compared with the controls, shikonin significantly induced cell apoptosis and reduced proliferation in a dose-dependent manner. Specially, lower concentrations of shikonin (1–2.5 μg/mL) cause viability reduction; apoptosis and cellular senescence induction is associated with upregulated expressions of cell cycle- and apoptotic signaling-regulatory proteins, while higher concentrations (5–10 μg/mL) precipitate both apoptosis and necrosis. Treatment of cells with pifithrin-α, a specific inhibitor of p53, suppressed shikonin-induced apoptosis and premature senescence, suggesting the role of p53 in mediating the actions of shikonin on regulation of lung cancer cell proliferation. These results indicate the potential and dose-related cytotoxic actions of shikonin on A549 lung cancer cells via p53-mediated cell fate pathways and raise shikonin a promising adjuvant chemotherapeutic agent for treatment of lung cancer in clinical practice

Endovascular treatment of a nontraumatic left subclavian artery pseudoaneurysm

Mycotic subclavian artery pseudoaneurysms are rare. There are controversies over the surgical or endovascular approach as the treatment of choice for these lesions. The standard surgical debridement might not be a choice for poorly surgically reachable lesions or for patients with multiple comorbidities. Endovascular aneurysm repair may be an effective alternative in selected cases. This treatment was rarely reported previously. Herein, we present a high-surgical-risk case with a highly suspected left subclavian arterial mycotic pseudoaneurysm, which, although difficult to approach surgically, was successfully managed with stent grafting and a complete antibiotic treatment course. An 89-year-old male was admitted due to intermittent fever and hemoptysis for 2 months. Salmonella group B was cultured from his sputum, and a 3.5 cm pseudoaneurysm was identified by chest multidetector-row computed tomography (MDCT) angiogram. Endovascular treatment with a graft stent was chosen due to high surgical risk and difficult surgical access to the lesion. The intervention was well planned ad hoc, based on MDCT images and meticulously performed by dual endovascular approaches. Antibiotics were continued after the procedure, and the patient was discharged from the hospital. As MDCT disclosed near-complete regression of the pseudoaneurysms 2 months later and the patient was in healthy status, antibiotics were continued for 6 months. He was readmitted 11 months later due to lacunar infarction with minor pneumonia over the left lower lung in which Salmonella enteritis was also diagnosed. After this acute event, he was again hospitalized 14 days later due to sepsis with adult respiratory distress syndrome and shortly expired despite all emergent treatment measures. No evidence of local subclavian infection recurrence was noted throughout or related to subsequent events. In conclusion, endovascular treatment of an infected subclavian artery pseudoaneurysm could be a choice in selected patients, but treatment of underlying infection determines the clinical outcome

The use and clinical outcomes of rotablation in challenging cases in the drug-eluting stent era

Background: Rotational atherectomy (RA) has been advocated in the bare metal stent (BMS) era but is underused now due to technique demands and nonsuperior outcomes. The aim of this study was to evaluate the procedural and clinical outcomes of patients with very complex, severely calcified coronary lesions treated by RA and drug-eluting stents (DESs) in our current percutaneous coronary intervention (PCI) practice in a region where RA use has been limited by lack of insurance reimbursement. Methods: From March 2004 to November 2010, all consecutive patients who required RA treatment for severely calcified de novo lesions of native coronary arteries followed by DES implantation were queried from the cath lab database and recruited. Their clinical and angiographic characteristics at the index PCI were analyzed and completed by a thorough review of the medical charts. Results: A total of 67 consecutive patients with 71 very complex, heavily calcified coronary lesions treated with RA plus DES were recruited. Of these patients, 64% presented with acute coronary syndrome, 9.0% with cardiogenic shock, 43.3% with chronic renal failure, and 50.7% with diabetes. Multiple-vessel diseases were found in 92.5% of our patients, and the average coronary artery calcification (CAC) score was 3.6±1.4. Of the coronary lesions, 26.7% were either balloon-uncrossable or balloon-undilatable. The angiographic success rate was 100% with one non-Q myocardial infarction. Five patients (7.5%) died in hospital, all initially presenting with extensive myocardial infarction and/or cardiogenic shock. The out-of-hospital major adverse cardiac event was 17.9% at the mean follow-up of 23.2 months (range: 5–86), primarily due to high target-lesion revascularization and target-vessel revascularization rates of 10.4% and 10.4%, respectively. Only one (1.5%) probable subacute stent thrombosis was observed in the follow-up. Conclusion: RA with DES implantation in very complex, heavily calcified coronary lesions can achieve very low complication and low out-of-hospital major adverse cardiac event rates even in high-risk patients despite use limited by lack of insurance reimbursement. The study results convince us to sustain and even broaden the use of this novel, but underused, device in the DES era

Using DNA Microarray to Identify Sp1 as a Transcriptional Regulatory Element of Insulin-like Growth Factor-1 in Cardiac Muscle Cells

High throughput gene expression profiling with DNA microarray provides an opportunity to analyze transcriptional regulation of hundreds or thousands of similarly regulated genes. Transcriptional regulation of gene expression plays an important role in myocardial remodeling. We have studied cardiac muscle gene expression with DNA microarray and employed a computational strategy to identify common promoter motifs that respond to insulin-like growth factor-1 (IGF-1) stimulation in cardiac muscle cells. The analysis showed that the Sp1 binding site is a likely target of IGF-1 action. Further experiments with gel shift assay indicated that IGF-1 regulated the Sp1 site in cardiomyocytes, by increasing the abundance of Sp1 and Sp3 proteins. Using firefly luciferase as reporter gene, additional experiments showed that IGF-1 activated the promoter of Cyclin D3 and Glut1. Both promoters contain one Sp1 site. The effect of IGF-1 on these two promoters was abolished with siRNA for Sp1. Thus, the transcriptional activation of these two promoters by IGF-1 requires the induction of Sp1 protein. These experiments suggest that the global transcriptional regulatory actions of IGF-1 involve activation of the Sp1 site in cardiac muscle. The computational model we have developed is a prototypical method that may be further developed to identify unique cis- and trans-acting elements in response to hormonal stimulation during cardiac muscle growth, repair, and remodeling in normal and abnormal cardiac muscle.