Indigo dyeing is an ancient technique that imparts a beautiful blue hue to fabrics and yarns. To dye yarn with indigo, you need a vat of indigo dye, which can be made using natural indigo powder, a reducing agent like sodium hydrosulfite, and lye to adjust pH. First, dissolve the indigo powder in hot water and let it cool. Next, add the reducing agent and stir gently to activate the dye. Afterward, gradually add lye while stirring. The vat is ready when it turns from greenish-yellow to dark brown. Rinse your yarn in cold water before submerging it into the vat. Leave it submerged for about 10 minutes, then remove and expose it to air, where oxidation will turn it blue. Repeat this process for deeper shades. Finally, rinse the yarn until the water runs clear, wash it with mild soap, and dry it away from direct sunlight.

In biochemistry, amino acids are categorized based on the properties of their side chains into basic, acidic, neutral nonpolar, and neutral polar. The basic amino acids have side chains that contain nitrogen and can accept a proton, making them positively charged at physiological pH. The three basic amino acids are Lysine (Lys, K), Arginine (Arg, R), and Histidine (His, H). Lysine and Arginine are always positively charged under physiological conditions, whereas Histidine, with its imidazole side group, has a pKa around physiological pH, which allows it to act as a proton acceptor or donor, playing a pivotal role in enzyme active sites. These properties make basic amino acids essential for protein structure due to their ability to form ionic bonds and participate in hydrogen bonding and are critical in protein-protein interactions and the binding of nucleic acids.

Polyethylene glycol 3350 (PEG 3350), commonly used as an osmotic laxative in treating constipation, can indeed cause gas among other gastrointestinal (GI) side effects. The mechanism involves drawing water into the bowel to soften stools, which can lead to increased gas production as a side effect. While not everyone will experience gas, it is listed among the potential side effects. To minimize discomfort, it's recommended to start with a lower dose and gradually increase as needed, while also staying hydrated. If gas or other side effects become bothersome, consulting a healthcare provider is advisable.