1 Pain that does not diminish with rest, and pain that may be worse at night than during the day. 2  Back pain along with constitutional symptoms, such as loss of appetite, unplanned weight loss, nausea, vomiting, or fever, chills or shakes.
Unstable chemicals. Onions produce the chemical irritant known as syn-propanethial-S-oxide. It stimulates the eyes' lachrymal glands so they release tears. Scientists used to blame the enzyme allinase for the instability of substances in a cut onion.
You refrigerate a cut onion for several reasons. One is that cutting into anything introduces bacteria, which will grow more quickly and cause spoilage faster at room temperature.When you cut the onion, you also rupture the cells, which leak moisture and cause spoilage. Again, that happens faster at room temperature.And cutting an onion releases more odor, so the smell of a cut onion at room temperature will be noticeable pretty quickly. According to the Heinz Web site, ketchup is very acidic, so it doesn't spoil easily.ne is that cutting into anything introduces bacteria, which will grow more quickly and cause spoilage faster at room temperature. When you cut the onion, you also rupture the cells, which leak moisture and cause spoilage. Again, that happens faster at room temperature.