Core Viewpoint - The article discusses the reasons why white clothing turns yellow over time and provides methods for prevention and restoration of whiteness. Group 1: Reasons for Yellowing - Yellowing can occur in specific areas or uniformly across the fabric, indicating multiple complex causes [6] - Sweat and skin oil residues can oxidize and create yellow substances, making it harder to clean if not addressed promptly [7] - Certain fabric materials, such as nylon and silk, are prone to yellowing due to their chemical structure containing amino groups that oxidize in air [8] - Improper cleaning and storage can lead to bacterial growth, which produces carotenoid pigments that cause yellowing [9] - Alkaline detergents can create chromophores that lead to yellowing, suggesting that neutral or acidic detergents are preferable for maintaining whiteness [10] - Cheap plastic packaging may contain BHT, which can transfer to clothing and cause yellowing through oxidation [11] - Airborne pollutants and UV light exposure can also contribute to the yellowing of white fabrics [14][15] - Improper storage conditions, such as humidity, can promote mold growth that leads to yellow stains [16] Group 2: Prevention Methods - To prevent yellowing, it is recommended to use neutral detergents, wash white clothes separately, and promptly address stains [18] - Avoid direct sunlight when drying white clothes to prevent UV damage [19] - Proper storage involves cleaning clothes before storage and maintaining a dry environment to prevent mold [20] Group 3: Restoration Methods - For restoring yellowed white clothes, methods include soaking in sodium percarbonate, which releases active oxygen to break down yellowing substances [21] - DIY options like using bulk sodium percarbonate can effectively bleach without damaging fabric dyes [21] - Textile fluorescent whitening agents can also be used, but caution is advised against using chlorine bleach, which can damage fabric and color [22]

Core Viewpoint - The article highlights the dual nature of the medical knowledge dissemination ecosystem on social media, where some medical professionals misuse their authority for commercial gain, leading to the need for regulatory measures to ensure ethical practices in health-related content [5][10][12]. Group 1: Medical Professionals and Commercialization - Some medical professionals are using their authority to promote non-medical products, such as hand creams and dietary supplements, under the guise of health education [5][6]. - Certain influencers are misrepresenting their professional identities by using titles like "doctor" or wearing lab coats to gain credibility while promoting products [7][10]. - There are instances where medical professionals provide misleading information or promote unrelated products, such as a urologist discussing foot fungus treatments, which raises ethical concerns [8][10]. Group 2: Regulatory Measures - In March, Shanghai introduced the first "negative behavior list" for internet health education, outlining prohibited actions such as disguised product promotion and collaboration with disreputable agencies [5][11]. - The article mentions that existing laws already impose strict regulations on medical advertising and the conduct of medical professionals online, including penalties for impersonating doctors or providing unauthorized medical advice [11][12]. - The need for a return to the altruistic roots of medical practice is emphasized, advocating for a healthier online environment that prioritizes public benefit over commercial interests [12].