Newsletter No. 526

07 # 5 2 6 | 0 4 . 1 1 . 2 0 1 8 一億難買心頭好 Million-dollar Tableware 周日就是雙十一，有網購習慣的朋友想必已蓄勢待發，準備一舉把覬覦良久的心頭好都 一一買下吧？對收藏家來說，讓他們這樣血脈賁張的，可能就是各大拍賣會了。在上月完 結的蘇富比秋拍，一件「乾隆御製琺瑯彩虞美人題詩盌」瓷碗以1.69億成交，備受矚目。 到底琺瑯彩是甚麽呢？又為甚麽會價值連城？ 琺瑯彩是一種含有玻璃及金屬氧化物的鮮艷顏料，按施加工藝可分為掐絲琺瑯 （ cloisonné ）、內填琺瑯（ champlevé ）和畫琺瑯（ painted enamel ）。掐絲琺瑯出現得最早， 一般相信是元朝時從拜占庭帝國傳入，但具體情況難以重構。其製作方法是先以金屬絲 在器物表面繞成花紋，形成不同空格，再填入各種顏色的琺瑯料。燒製後彩料會收縮下 陷，所以需要不斷重覆步驟直到空格完全填滿，仔細拋光後才告完成，工藝相當繁複。俗 稱「景泰藍」的銅胎掐絲琺瑯器就是此工藝最為人熟悉的例子。不過掐絲琺瑯其實除常 見的藍色外，也有其它顏色。例如文物館收藏的「大清乾隆年製」款掐絲琺瑯福壽紋高足 盤（下圖最底）就用了不少明亮的黃色琺瑯彩。 早期的掐絲琺瑯工匠面對兩個主要難題：其一是琺瑯料在燒製時會往下流淌，溢出金絲 的圍繞；其二，器表常有稱為「砂眼」的氣孔，影響外觀。據劉良佑研究，針對前者，明代 的工匠從瓷釉中得到靈感，成功透過加入氧化鋁減低琺瑯料流動性；至於後者，清代的工 匠意識到可能是源於焊接金絲的焊劑和其他顏料雜質等問題，遂研發出以植物膠黏貼金 絲、在顏料中減少硼酸鹽或加添瓷土、延長燒製時間以供器表氣體排出等改善方法。 至於內填琺瑯，其實也需要於胎面做出空格以供填入色料，只是其凹處是以壓模或雕刻 製作。畫琺瑯則是直接畫上紋飾，與前兩種差異比較大，對彩料流動性、燒造環境等要 求也自不同。這種技術於康熙初年才透過歐洲商人和傳教士傳入，首先應用於金屬器上， 由廣東率先開始生產，並提供了人員和技術，支持清宮探索畫琺瑯技術。銅胎畫琺瑯成功 後，再經過長期的研究，直到康熙末年，畫琺瑯技術才成功應用於與金屬表面特性迥異的 瓷胎上，可見琺瑯彩瓷工藝之難度，也解釋了其珍罕之處。 承蒙物理系 吳恒亮 教授支持文物館的「學科交響」計劃，以上內容曾於UGEB2650材料 科學概論課堂上與學生分享。中國古代沒有現代意義上的材料科學學生，但製作琺瑯器 的工匠們對金屬、陶瓷等材料在物理和化學上的把握實在讓人嘆服不已。 前列腺癌 ─ 熟男忌諱？ The Removal of a Taboo 在西方國家，男士患前列腺癌的一生累計風險，是每一百人有十七人。香港則是一百人中 有三人，儘管比例不高，前列腺癌近年已躍升至本港男性第三大癌症。 堂堂男子，入五登六，勞碌半生，本應享受人生，若某天有尿頻、血尿的徵狀，勢必晴天霹 靂，求醫嗎？病徵已經難以啟齒，若確診為前列腺癌，要動手術切除，會不會從此不能人 道？然而，與其讓疑竇發酵醞釀，不如問個明白。再者，前列腺癌不如想像中可怕。 首先，即使出現排尿困難，也不代表確診患癌。中大何善衡泌尿中心主任 吳志輝 教授說： 「前列腺增生的病徵與前列腺癌相似，若出現病徵，便要進一步檢查。」目前醫學上認為 前列腺增生不會轉變為前列腺癌。肛門指診或血液測試是兩種常用檢查方式，前者檢查 前列腺有沒有腫塊、硬塊；後者則量度血液中前列腺特異抗原濃度。有家族病歷史的男 士，從四十五歲起宜接受定期血液測試。 第二，即使確診患癌，甚至要接受前列腺切除手術根治，中大早於2005年已引入機械人手 術系統，把手術的後遺症降至最小。只要在病人腹部開數個五至十毫米的小孔，便可進行 前列腺切除手術。除了傷口細小、加速病人康復外，也可協助保存勃起功能和改善尿控功 能。接受切除手術的病人只有百分之五至十在一年後仍小便失禁。 第三，相對其他癌症，前列腺癌生長緩慢。吳教授指出，部分最早期的低風險前列腺癌不 一定要治療，畢竟切除手術和化療等舒緩性治療都有其副作用，因此若腫瘤極細小，醫生 或會考慮緊密監察，延遲承受治療所帶來的影響。 In Western countries, about 17 out of 100 men would suffer from prostate cancer over their life spans. Although the morbidity rate is much lower in Hong Kong, only three out of 100 men, prostate cancer has become the third most common type of cancer among men in the city. Something wrong with the sensitive tissue is a sensitive issue, particularly for men entering their 50s or 60s. If one finds oneself visiting the toilet suspiciously frequently or finds blood in the urine, fear is compounded by embarrassment. Surgical removal of the stem of the problem vividly but ghastly suggests castration. Instead of prostrating oneself before the unspeakable horror, one should seek professional advice from a doctor. Things might not be as grim as one fears. First, the appearance of symptoms such as difficulty in urination does not necessarily mean prostate cancer. ‘The symptoms of prostate hyperplasia (enlargement) are more or less the same as those of prostate cancer. A patient with the symptoms may suffer from benign prostate hyperplasia (BPH) instead of prostate cancer. As such, further tests should be conducted,’ said Prof. Anthony Ng , Director of CUHK’s S.H. Ho Urology Centre. It is believed that prostate enlargement does not lead to cancer. Digital rectal examination (DRE) and prostate-specific antigen (PSA) blood test are two common screening tests. During DRE, a doctor would feel if the prostate has any abnormal growth. In the blood test, the level of PSA, a marker of prostate cancer found in the gland, would be measured. Men above the age of 45 with family history should take the blood test regularly. Secondly, all is not lost in the case of a diagnosis of prostate cancer and removal of prostate gland is required. CUHK has since 2005 introduced robotically assisted approach to the surgery which could minimize the side effects. The removal of prostate gland is conducted through a few 5–10mm incisions in the abdomen. Not only is the patient’s recovery expedited but the approach can also help preserve potency and improve continence. Only about five to 10 per cent of patients who have their prostate gland removed still have urinary incontinence after the first year. Thirdly, compared with other types of cancer, prostate cancer grows slowly and a doctor may monitor the patient for a while before suggesting treatment. Professor Ng pointed out that treatment is not a must for patients with very early prostate cancer, given the side effects of the surgery and palliative treatments. If the tumour is very small, the doctor may recommend careful monitoring so that the patient can withhold the adverse impacts from treatments. M. Mak 雅 共 賞 / ART iculation 醫醫筆寫 / D octors ’ N otes 銅胎畫琺瑯 瓷胎畫琺瑯 掐絲琺瑯