Issue 029, 2025 SCIENCE FOCUS A New Explanation of “Like a Moth to a Flame” 「飛蛾撲火」新解 Wireless Charging Explained 無線充電大解構 Electric Eels: Shock You in More Than One Way 電鰻：水中的多重震撼 How to Regain Your Sleep from Your Smartphone? 如何從智能手機搶回睡眠時間？ Science Behind Auroras 極光的科學
Dear Readers, We bring you a bonus issue as you return to school after the Lunar New Year. Hopefully, you will find interesting new topics to discuss with your teachers and classmates after a well-deserved break. With smartphones being omnipresent, we provide a simple suggestion on how to prevent them from ruining your sleep. When you are not using them, how many of you charge your smartphones wirelessly? Have you wondered what wireless charging has in common with auroras, which were unusually common last year? A quick answer: magnetism. Moving on to animals, we challenge your prior knowledge on moth behavior and electric eels. Finally, we bring you the latest on our understanding of peanut allergy, and new therapeutic strategies that seem counterintuitive at first. The School of Science will be organizing a couple of all day activities in the spring. Please watch out for promotional material in our social media feeds. We hope to see you on campus in the not-too-distant future! Yours faithfully, Prof. Ho Yi Mak Editor-in-Chief 親愛的讀者： 我們很高興為你帶來農曆年假後額外出版的《科言》！希望你在 悠悠長假後，能在此找到與老師同學閒談的有趣新話題。 在智能手機變得無處不在的同時，今期我們會向大家提供避免讓 手機影響作息的小貼士。大家用完手機後會將它無線充電嗎？有想過 無線充電與上年難得廣泛出現的極光有甚麼關係？簡短答案：磁性。 然後我們會將話題轉向動物，挑戰你對飛蛾行為和電鰻的既有認知。 最後，我們會為大家介紹科學界對花生過敏的新知，以及驟聽之下少 許違反直覺的嶄新治療策略。 理學院在春季亦會舉辦多個全日活動，請密切留意我們在社交媒 體的宣傳，期望在不久將來能與大家在科大校園相遇！ 主編 麥晧怡教授 敬上 Message from the Editor-in-Chief 主編的話 Copyright © 2025 HKUST E-mail: sciencefocus@ust.hk Homepage: https://sciencefocus.hkust.edu.hk Scientific Advisors 科學顧問 Prof. Man Fung Cheung 張文峰教授 Prof. Yukinori Hirano 平野恭敬教授 Prof. Adrian Po 傅凱駿教授 Editor-in-Chief 主編輯 Prof. Ho Yi Mak麥晧怡教授 Managing Editor 總編輯 Daniel Lau 劉劭行 Student Editorial Board學生編委 Editors 編輯 Roshni Printer Minnie Soo 蘇慧音 Helen Wong 王思齊 Jane Yang 楊靜悠 Daria Zaitseva Social Media Editors 社交媒體編輯 Zoey Tsang 曾鈺榆 Navis Wong 黃諾軒 Graphic Designers 設計師 Coby Ngai 魏敏儀 Winkie Wong 王穎琪 Constance Zhang 張粲璨 Contents Science Focus Issue 029, 2025 What’s Happening in Hong Kong? 香港科技活動 Jane Goodall – Reasons for Hope 1 珍古德 — 信有希望 The Sun, Our Living Star 太陽 — 生命之源 Science Today 今日科學 A New Explanation of “Like a Moth to a Flame” 2 「飛蛾撲火」新解 Wireless Charging Explained 5 無線充電大解構 Peanut Allergies Unshelled: 8 New Treatment and Preventive Measures 解密花生過敏：新療法與預防措施 Amusing World of Science 趣味科學 Electric Eels: Shock You in More Than One Way 11 電鰻：水中的多重震撼 How to Regain Your Sleep from Your Smartphone? 14 如何從智能手機搶回睡眠時間？ Science Behind Auroras 17 極光的科學
What’s Happening in Hong Kong? 香港科技活動 Fun in Spring Science Activities 春日科學好節目 Any plans for this spring? Check out the following events! 計劃好這個春天的課餘節目了嗎？不妨考慮以下活動！ Jane Goodall – Reasons for Hope 珍古德 — 信有希望 This documentary featuring Dr. Jane Goodall emphasizes her enduring optimism and commitment to raising environmental awareness. The show highlights successful restoration efforts, such as the transformation of polluted land in a Canadian mining town into a lush green oasis, and the reintroduction of the endangered American Bison by an indigenous North American tribe, the Blackfeet Nation. The show encourages viewers to embrace hope and take action for a sustainable future, particularly empowering youth to drive change. 放映日期： 現在至2025年3月14日 時間： 下午五時正（一、三至五） 上午十一時正、下午三時半及 八時正（六、日及公眾假期） 地點： 香港太空館天象廳 入場費： 標準票：40 元（後座）；30 元（前座） 優惠票：20元（後座）；15 元（前座） 這套由Jane Goodall博士主持的紀錄片 揭示了她對提高大眾保育意識的長期貢獻，以及 堅定不移的樂觀態度。透過激勵人心的故事，節 目展示了多個致力將環境復原的成功例子，例如 將加拿大一個採礦小鎮受污染的土地轉化為綠 洲，以及北美原住民「黑腳部族」幫助瀕臨絕種 的美國野牛重新立足美洲大地的故事。電影鼓 勵觀眾 ─ 尤其是青少年 ─ 抱持希望，並為締造 可持續的未來出一分力。 Show period: Now – March 14, 2025 Time: 5:00 PM (Mon, Wed to Fri) 11:00 AM, 3:30 PM and 8:00 PM (Sat, Sun and public holiday) Venue: Space Theatre, Hong Kong Space Museum Admission fee: Standard admission: $40 (stalls), $30 (front stalls) Concession admission: $20 (stalls), $15 (front stalls) The Sun, Our Living Star 太陽 — 生命之源 This Sky Show invites audiences to explore the deep fascination of humanity with the Sun, from ancient reverence to contemporary scientific insights. For billions of years, the Sun has been essential for life on Earth, influencing weather patterns and governing our daily rhythms. This show delves into the Sun’s formation 4.6 billion years ago, its mechanism to generate energy, and its impact on our lives. Highlights include Galileo's groundbreaking observations of sunspots, the phenomena of solar flares and auroras, and the advanced telescopes that enhance our understanding of this vital star. Read the articles on circadian rhythm and auroras in this issue and watch the show! Show period: Now – May 14, 2025 Time: 3:30 PM and 8:00 PM (Mon, Wed to Fri) 2:00 PM and 6:30 PM (Sat, Sun and public holiday) Venue: Space Theatre, Hong Kong Space Museum Admission fee: Standard admission: $40 (stalls), $30 (front stalls) Concession admission: $20 (stalls), $15 (front stalls) Remark: This show is not suitable for viewers sensitive to flashing lights. 放映日期： 現在至2025年5月14日 時間： 下午三時半及八時正（一、三至五） 下午二時正及六時半（六、日及公眾假期） 地點： 香港太空館天象廳 入場費： 標準票：40 元（後座）；30 元（前座） 優惠票：20元（後座）；15 元（前座） 備註： 本片不適宜對閃光敏感之人士觀看。 由古代敬畏到現今科學發現，此天象節目 邀請觀眾探索人類長久以來對太陽的著迷。數 十億年以來太陽一直對地球上的生物至關重要， 皆因它影響天氣規律，並掌管我們的晝夜節律。 本片會闡述太陽在46億年前的形成過程、其產 生能量的奧秘，以及對我們生活的影響。精彩內 容包括伽利略對太陽黑子的突破性觀測、太陽 閃焰和極光現象，還有使我們對這個生命之源有 更深認識的先進望遠鏡。不妨閱讀今期關於晝 夜節律及極光的文章，然後去看這套電影吧！ 1
If you ever lit a candle in the wilderness during nighttime, you would likely find moths (and other nocturnal insects) irresistibly drawn to the candle flame. This phenomenon is so common that there’s a phrase for it, “like a moth to a flame.” For centuries, scientists wondered what attracts insects to flames [1]. Some believe insects mistake flame light for an indicator of gaps between leaves, or a celestial compass like the moon. Others propose that the heat of the light draws them in, or that the intense light blinds them, causing erratic flight patterns. To answer this age-old question, researchers at Imperial College London recorded and analyzed high-resolution flight trajectories of insects under artificial lights. Surprisingly, their findings point to a new explanation: the dorsal light response (DLR) [1–3], a highly conserved behavior that keeps the dorsal side, or the back, of insects facing the brightest visual region. Flying insects need to stay upright to maintain correct flight orientation. Throughout the long history of insect flight evolution, the sky has consistently been the brightest region in the visual field, making it a reliable cue for determining which way is up. Thus, by leveraging DLR, flying insects can adjust their flight orientation with reference to the sky. This capability is especially critical for small insects flying with a relatively low inertia because the gravitational force they experience can often be masked by other forces exerted by wind or turbulence, so unlike humans and plants, gravity cannot be used as a reliable cue of direction. Let’s take a closer look at how the researchers arrived at this unexpected conclusion of DLR. The first clues for DLR emerged from initial field experiments in Costa Rica, where the team used infrared high-speed cameras (Footnote 1–2) to record insect flight under various lighting configurations. Upon analyzing the recordings, researchers observed three unusual behaviors that are common in conditions with light but not in complete darkness (Figure 1). When the insects are at the same horizontal level as the light source, they orbit around it. If the insects are above “Like a Moth to a Flame” 「飛蛾 A New Explanation of Figure 1 Insect flight trajectories demonstrating the three unusual behaviors observed during field experiments: orbiting (left), inverting (middle), and stalling (right). 圖一 研究人員在野外實驗觀察到的三種不尋常昆蟲飛行軌跡：繞圈（左）、上下顛倒（中）和失速（右）。
3 By Helen Wong 王思齊 the light source, they inverse, or flip upside down, and crash onto the ground. While below the light source, the insects fly upward and then stall, or slow down. Most importantly, in all three scenarios, the insects tilted their backs toward the light source. Combining all lines of evidence, the most plausible explanation is that the insects are trying to align their backs to the light source under the influence of DLR. Nonetheless, these are just qualitative observations — can we possibly quantify this “dorsal tilting toward light” behavior? An intuitive approach is to track the insects’ flight paths and measure their body orientation as they fly. Back in the lab, the researchers conducted similar flight experiments, this time attaching position markers to several species of interest: Common Darter and Migrant Hawker dragonflies, as well as Yellow Underwing Moths and Lorquin’s Atlas Moth. They then projected the velocity vectors of the insects onto the ground and compared them to the instantaneous direction of light. Results showed that the insects mostly moved at right angles to the direction of the light source (Figure 2) – a piece of strong evidence that the insects are not attracted to the light, but are instead caught in loops around it as they aligned their backs to it due to DLR. The team demonstrated, through simulated flight experiments, that DLR alone is sufficient to produce the observed behavior in both field and lab settings. The significance of this study goes beyond merely answering a longstanding question; it also carries important implications for our use of artificial light. As human civilization progresses, we increasingly rely on artificial lighting at night for convenience, often not realizing that these lights could confuse insects. While many artificial light sources, like streetlamps, are essential, we can still make changes to help. By simply getting rid of unnecessary upward-facing lights that disorient insects and cause them to crash onto the ground (recall the inversion behavior!), we can seek a more harmonious coexistence with nature. 蛾 撲火」新解 1. Insect movements were captured using infrared illumination, as infrared light is assumed to be invisible to insects in this study [1]. This ensures their behavior remains unaffected during the flight experiments. In fact, none of the insects crashed into or interacted with the infrared lights set for videography purposes, which indirectly rejected the hypothesis that the heat of the light intervenes the flight of insects. 2. Videos in our daily life are filmed at 24, 25 or 30 frames per second (fps), while slow-motion videos are captured at 50 or 60 fps. In this study, they shot at an incredibly high frame rate of 500 fps. Figure 2 When insects tilt their backs toward the light source under DLR, their flight direction (solid arrow) will form a right angle to the direction of the light source (dashed arrow). 圖二 當昆蟲在背部光反應的影響下將背部朝向光源時，它們的飛 行方向（實線箭頭）會與光源方向（虛線箭頭）形成直角。 如果你在夜間的荒野點起燭光，你很可能會看見飛蛾 （和其他夜行昆蟲）出於本能反應撲向火焰。這種現象非 常普遍，以至於古人創作了一個成語來形容它：飛蛾撲火。 數世紀以來，科學家一直希望找出火焰吸引昆蟲的原 因 [1]。有人認為昆蟲誤將火焰當作樹葉間隙的線索，或是 當成月亮等可用作導航的天體；又有人提出昆蟲是被火焰 的熱力所吸引，又或是被火焰的強光致盲以致飛行路徑不 穩。 為了回答這個長久以來的問題，倫敦帝國學院的研究 人員記錄並分析了昆蟲在人工光源下的高解析度飛行軌 跡。令人意想不到的是，研究結果指向一個全新的解釋：背 部光反應（Dorsal Light Response / DLR）[1–3]，一種
References 參考資料： [1] Fabian, S. T., Sondhi, Y., Allen, P. E., Theobald, J. C., & Lin, H. T. (2024). Why flying insects gather at artificial light. Nature Communications, 15(1), 689. https://doi. org/10.1038/s41467-024-44785-3 [2] nature video. (2024, January 31). ‘Like a moth to a flame’ - this strange insect behaviour is finally explained [Video]. YouTube. https://www.youtube. com/watch?v=i7awa_WGI_o [3] Ravate, B. (2024, February 2). Flying insects become disorientated and trapped by artificial light. Imperial News. https://www.imperial.ac.uk/news/251217/flyinginsects-become-disorientated-trapped-artificial/ 普遍存在於多種昆蟲的高度保守（highly conserved） 行為，使昆蟲背部始終朝向視野中最明亮的區域。 飛行中的昆蟲需要保持背部朝上以維持正確的飛行 方向。在漫長的飛行進化史中，天空一直是視野中最明亮 的區域，因此成為了昆蟲辨認上方的可靠線索。透過背部 光反應，昆蟲就能以天空作參照來調整飛行方向。這對慣 性較低的小型昆蟲尤為重要，因為它們感受的重力往往會 被風或湍流施加的力所掩蓋，所以與人類和植物不同，這 些昆蟲不能倚靠重力作為判斷方向的依據。 現在讓我們仔細看看研究人員如何得出背部光反應 這個出乎意料的結論吧！ 背部光反應的最初線索來自研究團隊在哥斯達黎加 進行的野外實驗，他們使用紅外線高速攝影機（註一及二） 記錄昆蟲在不同照明配置下的飛行軌跡。在分析影片後， 研究人員觀察到三種在有光情況下出現，但在完全黑暗中 沒有出現的不尋常行為（圖一）：當昆蟲與光源處於同一水 平時，它們會圍繞光源飛行；如果昆蟲位於光源上方，它們 就會上下顛倒，然後墜落地面；如果昆蟲位於光源下方，昆 蟲則會改為向上飛行，漸漸失去前進的速度。最重要的一 點是在全部三種情況中，昆蟲均會把背部朝向光源。 綜合所有發現，最合理的解釋便是昆蟲在背部光反應 的影響下試圖將背部對準光源。可是，以上的結論只是基 於定性觀測 — 我們能否量化這種「將背部朝向光源」的 行為呢？ 一種直觀的方法是追蹤昆蟲的飛行路徑並測量它們 飛行時的身體方向。回到實驗室後，研究人員進行了類 似的飛行實驗，這次他們在以下數種昆蟲身上附加位置 標記：條斑赤蜻、混合蜓、大黃夜蛾和蛇頭蛾。接著，他 們將昆蟲的速度向量投影到地面，並將其與光的瞬時方 向進行比較。結果顯示，昆蟲大多以與光源方向成直角 的方式移動（圖二），證明昆蟲並非被光吸引，而是在試 圖將背部朝向光源方向的情況下被迫繞著光源飛。團隊 通過模擬飛行實驗進一步表明，單靠背部光反應就足以 在野外和實驗室環境中產生觀察到的行為。 這項研究的意義不僅在於回答了這個長久以來的問 題，亦為我們應如何設置燈光帶來重要的啓示。隨著人類 文明進步，我們在夜間越發依賴人工照明的同時，往往沒 有意識到這些燈光會干擾昆蟲飛行。儘管許多人工光源 （例如路燈）已成為現代社會的必需品，但我們仍然有改 善空間，例如我們可以避免使用向上照射的光源，因為它 們會使昆蟲迷失方向並墜落地面（回想一下上下顛倒的行 為！）。哪怕只是微小的改變，也能讓我們以更和諧的方 式與大自然共存。 1. 在拍攝昆蟲移動時，選用紅外線照明的前設是昆蟲看不見紅外線，這樣才能 確保它們的飛行路徑不受拍攝用的燈光影響。事實上，實驗中沒有任何一隻 昆蟲撞上或飛向攝影用的紅外線燈具，這亦間接否定了光的熱力干擾昆蟲 飛行這一假設。 2. 日常生活中的影片通常以每秒24、25 或 30 幀拍攝，而慢動作影片則以每秒 50或60幀拍攝。在這項研究中，研究人員以高達每秒500 幀的速率進行 拍攝。
5 WIRELESS CHARGING 無線充電 Explained 大解構 By Daria Zaitseva Wireless technology is the new black. Latest technological advances helped us ditch the hassle of cables and enjoy seamless use of devices with wireless charging pads and stands. Have you ever wondered how these chargers work? The answer is much simpler than you might think! Wireless charging, also called inductive charging, is based on some physical principles of electromagnetism and electromagnetic induction. The first principle to know is Ampere’s law, which implies that an electric current in a conductor generates a magnetic field with a strength proportional to the current. If we pass a current through a solenoid (a helical coil), the solenoid becomes an electromagnet with the north and south poles at either of its ends depending on the current direction. This is the transmitter coil installed in the charging pad. When the transmitter is plugged in, a current runs through the coil and turns it to an electromagnet. An alternating current (a.c.) with the direction of electron flow reverses regularly can be supplied, so that we get an electromagnet with the two poles switching constantly, creating a changing magnetic field. Then here comes the second principle: Faraday’s law of electromagnetic induction. Discovered by Michael Faraday in 1831, this law states that a changing magnetic field can induce a voltage called an electromotive force (e.m.f.), which can drive a current to flow through a conductor. Let’s say we take advantage of this principle and install a receiver coil into the device we want to charge. The coil picks up the changing magnetic field and develop an e.m.f. across it, eventually inducing a current to flow through the device. Voilà, the current is now transmitted wirelessly. As smartphones and watches can only be charged by direct current (d.c.), there is an electrical device called a rectifier to convert the induced a.c. into d.c. by restricting the electron flow to only one direction. Many people may not know: W i r e l e s s charging could be much more than a convenient accessory for your phone.
Researchers have long sought a wireless solution to power biomedical devices. Theoretically, magnetic fields can penetrate the skin to induce a current to charge the implanted device [1]. This capability could be a game-changer, eliminating the need of repeated surgeries to replace pacemaker batteries [2], and the infection risk associated with percutaneous wire insertion to power left ventricular assist devices (mechanical pumps for patients with advanced heart failure) [3]. Nevertheless, before the wireless charging technology can be commercialized in biomedical devices, some technical challenges still need to be overcome, such as misalignment between coils and burn injury caused by the highpower transmission [2, 4]. Wireless charging systems could be a future direction for electric cars as well. Mercedez-Benz has already been offering a wireless charging option in a car model back in 2017 [5]. Recently, the leading electric car company Tesla has also expressed interest in developing their own wireless charging technology [6]. However, infrastructural support, such as setting up charging stations with charging pads, is crucial to the promotion of the use of wireless charging. This may explain the general reluctance of car manufacturers to incorporate wireless technology into their products [6]. It is a chicken and egg situation: The motivation of car companies to invest in wireless technology is driven by the demand of electric cars, which, however, is now hindered by the accessibility to public charging. Although a lot of development is still due, engineers have conceived some futuristic ideas in city planning. Detroit has built the first wireless charging road in the US with electromagnetic coils installed underground for pilot testing [7]. While driving down the 400-meter road, the car battery can be charged through inductive charging. This could be a solution to extend the range of electric vehicles. This is just a glance at what wireless charging could do. In a desire to make technology better and smarter, developers take on the responsibility to make our lives easier without wires. From homes to high-tech endeavors, more and more devices go wireless. What’s next? 無線技術是新潮流，科技進步使我們能擺脫電線的纏 繞，讓我們享受到以無線充電座或支架為手機充電的便利 體驗。你有想過無線充電器如何運作嗎？答案也許比你想 像的簡單得多！ 無線充電又稱為感應充電，運作原理基於電磁學和電磁 感應範疇中一些物理學原理。我們第一個要了解的是安培定 律，它表明導體中的電流會產生與其強度成正比的磁場。如 果我們為一個螺線管（螺旋線圈）接上電源，螺線管就會變 成一塊電磁鐵，兩端會根據電流方向一端成為南極，另一端 成為北極。 這就是安裝在充電座裡的發射線圈。當發射線圈插上電 源後，電流會通過線圈使其成為電磁鐵。如果接上交流電， 電子的流動方向會不停改變，使電磁鐵的兩極不斷互換，從 而產生不斷變化的磁場。 接下來是第二個原理：法拉第電磁感應定律。這個由米 高．法拉第（Michael Faraday）於1831年發現的定律指出 變化中的磁場可以感生出稱為電動勢的電壓，它可以驅使電 流在導體內流動。 如果我們利用這個原理，將一個接收線圈安裝到我們想 要充電的設備中，這個線圈就會接收到不斷變化的磁場，並 產生電動勢，最終感生出電流通過設備。現在我們不就是能 無線傳輸電流了嗎？由於智能手機和手錶只能用直流電充 電，因此有種稱為整流器的電子零件可以透過限制電流方 向，將感生而來的交流電轉換成直流電。 許多人可能不知道，無線充電並不僅被用於手機充電，研 究人員亦一直尋求為醫療儀器無線供電的方案。理論上，磁 場可以穿透皮膚並感生電流為已植入體內的儀器充電 [1]。 這個原理未來可能會帶來革命性的改變，讓使用心臟起搏器 的患者不再需要接受重複手術以更換電池 [2]，亦能使植入 左心室輔助裝置（供末期心臟衰竭患者用的機械泵）的患者 不再需要透過皮下導線供電，從而避免相關感染風險 [3]。 然而，在應用無線充電技術的醫療儀器商品化之前，設計人 員仍需克服一些技術挑戰，例如線圈之間的錯位問題和高功 率傳輸造成的燒傷等 [2, 4]。 無線充電系統亦可能是電動車的未來方向。平治 （Mercedez-Benz）早在 2017 年就已經為旗下一款汽車型號 提供無線充電選項 [5；] 最近電動車公司的領頭羊特斯拉（Tesla） 也表示對開發自家無線充電技術感興趣 [6]。可是，建設基礎設 施對推廣無線充電至關重要，例如設立更多設置充電板的充電 站等，這某程度上解釋了汽車製造商普遍不願意將無線技術納 入其產品的原因 [6]。這是個「先有雞還是先有蛋」的問題：驅使
References 參考資料： [1] Mussivand, T., Miller, J. A., Santerre, P. J., Belanger, G., Rajagopalan, K. C., Hendry, P. J., Masters, R. G., Holmes, K. S., Robichaud, R., Keaney, M., Walley, V. M. & Keon, W. J. (1993). Transcutaneous Energy Transfer System Performance Evaluation. Artificial Organs, 17(11), 940– 947. https://doi.org/10.1111/j.1525-1594.1993.tb00407.x [2] Salloum, W., Ghosson, Y., & Fardoun, A. (2022). Wireless Pacemaker Battery Charger. 2022 IEEE 4th Eurasia Conference on Biomedical Engineering, Healthcare and Sustainability (ECBIOS). https://doi.org/10.1109/ ECBIOS54627.2022.9944998 [3] Pya, Y. (2020). Transcutaneous Energy Transmission: Can we do it now? The VAD Journal, 6(2), e2020624. https:// doi.org/10.11589/vad/e2020624 [4] Horie, H., Isoyama, T., & Ishiyama, K. (2023). Design of an Innovative Wireless Left Ventricular Assist Device Driven by either Extracorporeal Magnets or an Intracorporeal Battery Pack. ASAIO Journal, 69(2), e73-e79. https://doi.org/10.1097/MAT.0000000000001874 [5] Mercedes-Benz of Silver Spring. (n.d.). Mercedes-Benz, Qualcomm Unveil Wireless Charging for Plug-in Hybrid S-Class. https://news.mercedesbenzsilverspring.net/ article/mercedes-benz-qualcomm-unveil-wirelesscharging-for-hybrid-s-class [6] Alake, T. (2024, February 20). Wireless Charging for Electric Cars Is Inching Closer to Reality. Bloomberg. https://www.bloomberg.com/news/articles/2024-02-20/ wireless-charging-for-electric-cars-is-inching-closer-toreality [7] Paris, M. (2022, January 31). Wireless charging: The roads where electric vehicles never need to plug in. BBC. https://www.bbc.com/future/article/20240130wireless-charging-the-roads-where-electric-vehiclesnever-need-to-plug-in 7 汽車公司投放資源於發展無線技術的誘因是電動車的需求，但 目前這一需求又受制於公共充電設施的普及性。 儘管技術離發展成熟還有一段距離，但工程師們已經在城市 規劃方面構想出一些具前瞻性的新穎想法。底特律就建造了美國 第一條無線充電道路進行試點測試 [7]，在道路下方安裝了電磁 線圈。當車輛駛過這條 400米長的道路時，車輛電池就能夠進 行感應充電。這方案有望在未來被用於延長電動車的續航力。 這只是無線充電在未來可行應用的數例。為了讓技術變得 更智能和實用，開發者肩負起讓我們生活變得不受拘束的責 任。從家居應用到高科技產業，越來越多設備走上無線化的道 路，接下來的設備又會是哪個呢？
Peanut Allergies Unshelled: New Treatment and Preventive Measures Have you ever felt the craving for a warm peanut butter and condensed milk toast? While most of us can probably relate, peanut allergy is one of the most common food allergies. It typically develops in early childhood and persist in around 80% of patients for life [1, 2]. In severe cases, life-threatening symptoms can occur after ingestion of even a small trace of peanut. The presence of these traces in everyday meals makes it challenging to avoid accidental ingestion. In the past, “treatment” of peanut allergy was largely limited to complete avoidance. However, recent studies have brought forward ways to prevent as well as manage this common condition: Let’s delve into them and crack the peanut allergy! In 2015, a landmark clinical trial published in the New England Journal of Medicine suggested that the introduction of peanuts in the diets of infants at risk could prevent the development of peanut allergy [3]. The mechanism is called desensitization: a treatment to increase the body’s tolerance to peanuts by exposing the infant to an increasing amount of peanut antigen, the allergy-causing component in peanuts. Termed “oral immunotherapy,” desensitization can modify the developing immune system of infants so that peanuts can be recognized by the body as a safe food instead of a threat. In May 2017, after taking recent evidence into consideration, the United States National Institute of Allergy and Infectious Diseases (NIAID) recommended early introduction of peanuts to infants at risk, especially to those aged four to six months with severe eczema and/or egg allergy [4]. Preliminary immunological test should be conducted to infants with severe eczema and/or egg allergy to ensure safety and to determine the preferred method of the administration of dietary peanut. However, their recommendation for infants who had already been identified as allergic was avoidance. In 2023, further data from a new study urged the promotion of this preventive intervention to the general population [5]. Compared to the marginal reduction of 4.6% by targeting only the highest-risk infants with severe eczema, extending the scope to all infants could lower the prevalence by 77%. The study also showed that the older a child grows, the less effective the intervention would become. This could explain the tenfold lower rate of peanut allergy in the children in Israel,
9 解密花生過敏： 新療法與 預防措施 where peanut is frequently fed to infants in large quantities as snacks, when compared to the UK [6]. This prompted the National Health Service (NHS) of the UK to recommend introducing crushed or ground peanuts, or peanut butter to infants from the age of six months, after the infant is ready to ingest solid foods [7, 8]. The breakthroughs in the study of peanut allergy also came with the development of Palforzia, a novel drug for young patients already diagnosed with peanut allergy. Targeting patients aged from four to 17 years old, this drug was approved by the US Food and Drug Administration (FDA) in January 2020 [9]. It contains peanut allergens in powder form which can be ingested with a soft food [10]. By gradually escalating the dose until a limit is found, the patient can build up tolerance to small amounts of peanut protein. After the up-dosing stage, the patient will need to take a maintenance dose every day for the treatment to remain effective. This fact, combined with the high cost and the requirement of biweekly visits to doctors in the first six months of the treatment discouraged the widespread use by patients, especially during the pandemic shortly after its launch. These limitations eventually led to Palforzia’s flop in sales – showing us how a medical breakthrough does not necessarily lead to a successful business [10, 11]! The study of peanut allergy highlights the tentative nature of science – scientific theories are subject to change when new evidence arises. Therefore, it is crucial to be open-minded and keep abreast of the latest developments in scientific research. Before you share this article to those with peanut allergy, please 你試過突然想吃熱烘烘的花生醬煉乳多士嗎？ 雖然我們大多數人都會有共鳴，但花生過敏是最常見的 食物過敏之一。它通常從幼兒期開始出現，過敏情況在約八 成患者中會持續終生 [1, 2]。在嚴重個案中，即使攝入微量 花生也能導致危及生命的症狀，然而花生的蹤影在日常膳食 中可謂無處不在，使過敏者難以完全避免攝入花生。在過去， 花生過敏的「治療方法」僅限於避免進食花生，但近年研究 提出了預防和減輕這種常見過敏的方法。讓我們深入了解， 並嘗試破解花生過敏的難題吧！ 2015年，《新英格蘭醫學雜誌》（New England Journal of Medicine）發表了突破性的臨床試驗結果，指出 在高風險嬰兒的膳食中加入花生有助預防花生過敏 [3]。當 中原理稱為「脫敏法」（desensitization）：透過讓嬰兒攝取 分量逐漸增加的花生抗原（花生的致敏成分），從而提高身 體對花生的接受程度。這種被稱為「口服免疫療法」的脫敏 治療能引導嬰兒發展中的免疫系統，使其將花生識別為可信 賴的安全食物而非外來威脅。 2017 年 5月，在考慮到最新證據後，美國國家過敏及傳 染病研究所（United States National Institute of Allergy and Infectious Diseases / NIAID）建議在高風險嬰兒（四 至六個月大患有嚴重濕疹或（及）雞蛋過敏）的膳食中引入 花生 [4]，但此前應先進行初步免疫學測驗，以策安全並找 出處方花生的最佳方法。儘管如此，研究所對已確診花生過 敏兒的建議仍然是避免攝取花生。 By Roshni Printer make sure they understand that any attempt on the new therapeutic strategies should be closely supervised by medical professionals.
2023年，來自另一項 研究的進一步數據建議將預防措施推廣至 所有嬰兒 [5]。與僅針對患有嚴重濕疹的高風險嬰兒能帶來 的 4.6%些微減少相比，將範圍擴大到所有嬰兒能將花生 過敏的患病率降低77%。研究還指出措拖成效會隨孩子年 齡增長而減低。這些結果或許能解釋以色列兒童的花生過 敏率比英國低十倍的原因，因為以色列家長會餵嬰兒進食 大量含花生的零食 [6]。這促使英國國民保健署（National Health Service / NHS）建議從六個月起及在嬰兒能進食固 體食物後，就應在其膳食中加入磨碎的花生或花生醬 [7, 8]。 花生過敏研究上的突破還促使一種新型藥物 Palforzia 的發展，這種藥物的對象是已被診斷為花生過敏的年輕患 者。該藥物針對四至 17歲的患者，於2020 年1 月獲美國 食品藥物管理局（US Food and Drug Administration / FDA）批准使用 [9]。Palforzia是含有花生過敏原的粉末， 可混入流質食物進食 [10]。透過逐漸增加劑量直至找到上 限，患者對花生蛋白的接受程度亦會漸漸增加，使其能接受 少量花生。在增加劑量的階段完結後，患者需要每天服用維 持劑量以維持療程效力。然而這一點，加上高昂的費用和療 程首六個月每兩週就需要就診一次的要求成為了Palforzia 未能普及的原因，尤其在推出後不久就爆發了新冠疫情，令銷 情雪上加霜。這些缺點最終導致 Palforzia 銷情慘淡，因此故 事告訴我們醫學上的突破未必等於商業上的成功 [10, 11]！ 花生過敏的研究帶出了科學的暫時性 — 當新證據出現 時，科學理論就會隨之變化。因此，保持開放和與時並進的心 態至關重要。在你分享這篇文章給花生過敏者前，請確保他 們明瞭任何新療法都應在專業醫療人員的密切監督下進行。 References 參考資料： [1] Whitsel, R. M, Bjelac, J. A., Subramanian, A., Hoyt, A. E. W., & Hong, S. J. (2021). Cleveland Clinic Journal of Medicine, 88(2), 104–109. https://doi.org/10.3949/ ccjm.88a.20130 [2] Al-Ahmed, N., Alsowaidi, S., & Vadas, P. (2008). Allergy, Asthma & Clinical Immunology, 4(4), 139–143. https://doi. org/10.1186/1710-1492-4-4-139 [3] Du Toit, G., Roberts, G., Sayre, P. H., Bahnson, H. T., Radulovic, S., Santos, A. F., Brough, H. A., Phippard, D., Basting, M., Feeney, M., Turcanu, V., Sever, M. L., Gomez Lorenzo, M., Plaut, M., Lack, G., & LEAP Study Team (2015). Randomized trial of peanut consumption in infants at risk for peanut allergy. The New England Journal of Medicine, 372(9), 803–813. https://doi.org/10.1056/NEJMoa1414850 [4] Togias, A., Cooper, S. F., Acebal, M. L., Assa'ad, A., Baker, J. R., Jr., Beck, L. A., Block, J., Byrd-Bredbenner, C., Chan, E. S., Eichenfield, L. F., Fleischer, D. M., Fuchs, G. J., III, Furuta, G. T., Greenhawt, M. J., Gupta, R. S., Habich, M., Jones, S. M., Keaton, K., Muraro, A., … Boyce, J. A. (2017). Addendum guidelines for the prevention of peanut allergy in the United States: Report of the National Institute of Allergy and Infectious Diseases-sponsored expert panel. Journal of allergy and clinical immunology, 139(1), 29–44. https://doi.org/10.1016/j.jaci.2016.10.010 [5] Roberts, G., Bahnson, H. T., Du Toit, G., O'Rourke, C., Sever, M. L., Brittain, E., Plaut, M., & Lack, G. (2023). Defining the window of opportunity and target populations to prevent peanut allergy. Journal of Allergy and Clinical Immunology, 151(5), 1329–1336. https://doi.org/10.1016/ j.jaci.2022.09.042 [6] Du Toit, G., Katz, Y., Sasieni, P., Mesher, D., Maleki, S. J., Fisher, H. R., Fox, A. T., Turcanu, V., Amir, T., ZadikMnuhin, G., Cohen, A., Livne, I., & Lack, G. (2008). Early consumption of peanuts in infancy is associated with a low prevalence of peanut allergy. Journal of Allergy and Clinical Immunology, 122(5), 984–991. https://doi. org/10.1016/j.jaci.2008.08.039 [7] Gallagher, J. (2023, March 17). Give babies peanut butter to cut allergy by 77%, study says. BBC News. https://www.bbc.com/news/health-64987074 [8] National Health Service. (2021, November 5). Food allergies in babies and young children. https://www. nhs.uk/conditions/baby/weaning-and-feeding/foodallergies-in-babies-and-young-children/ [9] U.S. Food and Drug Administration. (2020, January 31). FDA approves first drug for treatment of peanut allergy for children. https://www.fda.gov/news-events/pressannouncements/fda-approves-first-drug-treatmentpeanut-allergy-children [10] Aimmune Therapeutics. (2022). Palforzia Treatment Handbook. https://www.palforzia.com/sites/default/ files/2022-10/treatment_handbook.pdf [11] Halpert, W. (2022, December 3). Peanut allergies: Parents worry after Palforzia drug sales flop. BBC News. https:// www.bbc.com/news/world-us-canada-63788730 [12] Speed, M. (2023, September 4). Nestlé sells peanut allergy business after insufficient demand. Financial Times. https://www.ft.com/content/436756c9-80c5-499abddf-e7f56defe844
11 In 1800, the Italian scientist Alessandro Volta drew inspiration from the electric eel to create the first ever battery [1, 2]. Despite their name, electric eels are not true eels but share a striking resemblance [2]. These fascinating fresh-water knifefish possess a unique ability to discharge electricity, which can stun or even kill some animals. But how does it work? First, we should understand the concept of electric current, which is the flow of charged particles like electrons and ions. The difference in charges between two points generate a potential difference which results in a discharge when the circuit is complete, with the electric current inversely proportional to the resistance of the circuit. In the nervous system of living organisms, signals are transmitted in the form of electrical impulses. Similar to how a battery has positive and negative terminals, our neurons actively maintain different ion concentrations across the cell membrane, resulting in a potential difference inside and outside the cell. By opening and closing the ion channels in the plasma membrane in an ordered fashion, ions are allowed to flow across the membrane down the concentration gradient. The flow of ions eventually generates a pulse of current that relays a message across a nerve. Electric eels took it further. Up to 80% of their body consists of specialized organs involved in electricity generation [3]. The three organs, known as Sach's, Hunter's, and the main organ, are composed of modified flattened muscle cells called electrocytes. These tiny batteries are connected both in series and in parallel so the voltage and current add up respectively. When electrocytes receive a command to discharge, in the form of nerve signals, sodium channels in the plasma membrane will open, causing a flood of sodium ions (Na+) into the cells. This results in the accumulation of positive charges within the stacks of electrocytes, turning the entire body of the electric eel into one long battery, with a positive end at the fish’s head and a negative end at the tail. The voltage of this living battery can reach up to 600 V [1], which is almost three times of Hong Kong’s standard electrical voltage! To compensate for their weak eyesight, electric eels also set up low-voltage electric field to gauge their surroundings [4]. This feature enables them to live and hunt in the murky, slow-moving pools and swamps of the Amazon and Orinoco rivers of northern South America [2]. When an obstacle, prey, or a predator Shock You in More Than One Way 水中的多重震撼 By Daria Zaitseva Electric Eels 電鰻:
comes close, the fish’s electric field is disrupted. Even a tiny distortion, possibly as small as a microvolt per centimeter (10-6 V/cm) [4], can be detected by the electroreceptors distributed throughout the fish's body, alarming the knifefish. Once the fish detects an object that resembles prey, it will enter a typical attack mode [5, 6]. It will first generate a doublet of high-voltage electric discharges which can cause a powerful involuntary twitch in the hidden prey. The ripples generated can be sensed by the knifefish and reveal the location of the prey. Then the fish will fire a volley of high-voltage pulses to paralyze the prey and then swallow it. To give an even harder shock, the electric eel sometimes seizes their prey in its mouth and curls its body to bring the prey closer to the tail, so that the prey can experience a much stronger electric field [5]. This fascinating ability comes with a mystery: How does a knifefish avoid shocking itself? A theory states that the relatively large size of electric eels (they can reach 2.5 meters in length!) helps them withstand the current that is unbearable to their much smaller prey [7, 8]. Meanwhile, the insulating fat layers surrounding the electric organs [8] and the dissipation of current into water [7] protect the fish’s central nervous system and heart from being directly shocked by the strong current they just produce. Yet, there is indeed much more to be studied and discovered. 在1800年，意大利科學家Alessandro Volta受電 鰻的啟發，創造了第一顆電池 [1, 2]。雖然名字中有個「鰻」 字，但電鰻在分類上並不屬於鰻魚的一種 [2]，儘管兩者外 形非常相似。這些有趣的淡水刀魚擁有獨特的放電能力， 能使其他動物暈眩甚至死亡。到底箇中原理是甚麼呢？ 首先，我們須了解電流這個概念，就是帶電粒子（例如 電子或離子）的流動。兩點之間的電荷差異產生電勢差，當 電路接通時就會導致放電現象，當中電流大小與電路的電 阻成反比。 在生物的神經系統中，信號是以電脈衝的形式傳遞。類 似於電池有正負極，我們的神經元會主動地維持細胞膜兩 邊離子的不同濃度，使細胞內外有著電勢差。透過有秩序 地開關細胞膜中的離子通道，離子就可以順濃度梯度穿越 細胞膜。離子的流動最終產生一波電脈衝，將信息從神經 一端傳遞至另一端。 然而電鰻將生物放電的潛能發揮到極致。牠們身體八 成均由與放電相關的特化器官組成 [3]，這三個器官分別 是石赫氏器官（Sach's organ）、亨特氏器官（Hunter's organ）和主器官（main organ），由稱為「發電細胞」的 特化扁平肌肉細胞組成。這些微小的電池同時以串聯和並 聯方式連接，分別使電壓和電流得以累加。當發電細胞接 收到指示它們放電的神經信號時，細胞膜中的鈉通道會打 開，使鈉離子（Na+）湧入細胞。這使一群群堆疊的發電細 胞內部積聚大量正電荷，將電鰻身體變成一條長長的電池 — 魚的頭部為正極，尾部為負極。這塊「活電池」的電壓可 以高達 600 伏特 [1]，幾乎是香港標準電壓的三倍！
13 為了彌補視力上的不足，電鰻還能透過設置低電壓的電 場以探測周圍環境 [4]，使牠們能在南美洲北部亞馬遜河和 奧里諾高河一帶混濁的死水和沼澤中生活和捕獵 [2]。當障 礙物、獵物或捕食者靠近時，魚的電場會受到干擾；而即使 是細小至每厘米一微伏（10-6 V/cm）[4] 的電場扭曲，也能 被散佈在電鰻身體上的電感受器偵測到，使電鰻能察覺四 周。 一旦電鰻偵測到類似獵物的物體，就會進入典型的攻擊 模式 [5, 6]。電鰻首先會以高電壓連續兩下放電，使躲藏的 獵物不自主地強烈抽搐。泛起的漣漪能被電鰻感知，從而揭 示獵物的位置。然後電鰻會以一連串高壓脈衝掃射獵物，使 其麻痺再把其吞下。有時為了施以更強烈的電擊，電鰻會用 口叼住獵物並捲曲身體，將獵物拉近尾部，把獵物扯進更強 烈的電場 [5]。 這驚人能力背後還有一個不解謎團：電鰻如何在放電 中保護自己免受電擊？有理論認為電鰻相對較大的體型 （可達 2.5米長！）能幫助牠們承受細小獵物無法忍受的電 流 [7, 8]。與此同時，包圍著放電器官的絕緣脂肪層 [8] 和 在水中散失的一部分電流 [7] 保護了電鰻的中樞神經系統 和心臟，避免其受自己發出的強大電流直接衝擊。儘管如 此，關於電鰻，確實還有許多東西需要進一步研究和發現。 References 參考資料： [1] SPARK Museum of Electrical Invention. (n.d.). Volta’s Fishy Invention. https://www.sparkmuseum.org/voltasfishy-invention/ [2] Chetan-Welsh, H. (n.d.) How do electric eels work? Natural History Museum. https://www.nhm.ac.uk/ discover/how-do-electric-eels-work.html [3] The University of Western Australia. (2015, February). Electrical circuits 6: Electric eels (fact sheet). https:// www.uwa.edu.au/study/-/media/faculties/science/ docs/electric-eels.pdf [4] Bennett, M. V. L. (1971). Electroreception. In W. S. Hoar, & D. J. Randall (Eds.), Fish Physiology (pp. 493–574). Academic Press. https://doi.org/10.1016/S15465098(08)60038-2 [5] Catania, K. C. (2019, April 1). Shocking Secrets of the Electric Eel. Scientific American. https://www. scientificamerican.com/article/shocking-secrets-ofthe-electric-eel/ [6] Catania, K. (2014). The shocking predatory strike of the electric eel. Science, 346(6214), 1231–1234. https://doi. org/10.1126/science.1260807 [7] Scientific American. (2005, December 5). How do electric eels generate a voltage and why do they not get shocked in the process? https://www. scientificamerican.com/article/how-do-electric-eelsgene/ [8] BBC Wildlife Magazine. (2023, July 3). How an electric eel works: You wouldn't want to be on the receiving end of its high voltage charge. https:// www.discoverwildlife.com/animal-facts/fish/how-anelectric-eel-works
By Jane Yang 楊靜悠 In our modern, hyper-connected world, smartphones have become ubiquitous companions for many of us. However, the convenience and allure of these devices may come at a cost, particularly when it comes to our sleep habits. Do you find yourself habitually reaching for your smartphone as you wind down for the night, only to find yourself hours later still scrolling through endless social media feeds or watching video after video? If so, you're not alone. Let’s explore the impact of bedtime smartphone use on our circadian rhythms — the body's internal clock that controls our sleep-and-wake cycles. Toward the end, we will provide some insights on how to regain a restful sleep. Blue Light from Electronic Screens Modern electronic screens, from smartphones to computer monitors, utilize the RGB color model to display a wide range of hues. This method relies on mixing varying intensities of the three primary colors — red, green, and blue. However, what many don't realize is that blue light has a profound impact on our circadian rhythms [1, 2]. Melatonin-Suppressing Effect of Blue Light Our body’s biological clock needs to be calibrated every day, so that our behavior and physiology can optimally adapt to the external day-night cycle [3]. Sunlight is composed of light waves of all the visible colors, of which retinal ganglion cells have been shown to play a key role in detecting blue light to synchronize our circadian rhythms [4]. Retinal ganglion cells are photoreceptors that do not contribute to our visual perception. However, in response to blue light, they will send signals to the suprachiasmatic nucleus (SCN) — a structure located in the anterior part of the hypothalamus [5] — to tell the brain that it is daytime. The SCN then regulates the release of melatonin by the pineal gland — stimulation in darkness and suppression in light — to modulate internal biological events, such as sleep-wake cycles and some energy metabolism functions (e.g. glycogen synthesis and daily phase of high insulin sensitivity) [6]. The blue light exposure in the evening hours, therefore, confuses our brain and disrupts our sleep-wake cycles, making us difficult to fall asleep. The mechanism by which blue light from electronic screens disrupts our circadian rhythms is similar to jet lag. When we traverse multiple time zones, our internal clocks struggle to immediately adjust to the new daylight pattern of the destination. This mismatch between our body's internal clock and the local time confuses our body, leading to symptoms like fatigue and difficulty sleeping. How to Regain Your Sleep from Your Smartphone? 如何從智能手機 搶回睡眠時間？
15 How to Resynchronize the Clocks? So, what can we do to stay away from the negative effects of blue light? Many smartphones nowadays have eye protection mode and dark mode [7]. After switching to eye protection mode, the screen will turn yellowish because some of the blue light is filtered, so the red and green lights, which add up to yellow, become more prominent. Alternatively, dark mode features white text against a black background to minimize our exposure to the blue light in white backgrounds. Turning on these modes before sleep can reduce the melatonin-suppressing effect of blue light, potentially leading to a better sleep. But these are just some long-term measures. What if I have an important event the following day but find myself unable to sleep due to the recent late-night use of smartphone? And what if I am suffering from jet lag? You can try taking melatonin as an emergency remedy under the instructions provided with the medicine or by your doctor [8, 9]. Taking melatonin two hours before the desired bedtime can promote sleep by putting you into a state of quiet wakefulness [8]. However, it is important to note that the effectiveness of melatonin can vary significantly between individuals [9]. We should always seek professional medical advice when in doubt. After all, the best way to avoid blue light-induced insomnia and drowsiness at work or school is to stick to a healthy and responsible sleep routine, minimizing screen time in the hours before bed. 在現今高度互聯的世界中，智能手機已成為我們無處 不在的搭檔。然而，尤其是在睡眠習慣方面，這些設備帶 來的便利和誘惑卻可能叫我們付出沉重的代價。您有否發 現自己在晚上休息時習慣性地拿起手機，數小時後仍在瀏 覽社交媒體或觀看一條又一條的影片？如果你也是這樣， 不用怕，你絕不是少數。讓我們探討睡前使用智能手機如 何影響我們的晝夜節律，亦即是身體控制睡眠和覺醒週期 的內部時鐘。最後，我們將提供一些重拾優質睡眠的方法。 電子螢幕發出的藍光 從智能手機到電腦顯示器，現代電子螢幕利用 RGB 顏 色模型顯示不同顏色，這個方法透過混合不同強度紅、綠、 藍三種原色的光來產生各種顏色。可是，許多人沒有意識 到藍光會影響我們的晝夜節律 [1, 2]。
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