Gray baby syndrome has been noted to be dose-dependent as it typically occurs in neonates who have received a daily dose greater than 200 milligrams.When chloramphenicol is necessary, the condition can be prevented by using chloramphenicol at the recommended doses and monitoring blood levels, or alternatively, third generation cephalosporins can be effectively substituted for the drug, without the associated toxicity. Also, repeated course of administration and prolonged treatment should be avoided as much as possible. In terms of hepatic development in neonates, it take only weeks from birth for them to develop their UDPGT expression and function to be at an adult-like level, while the function is only about 1% in the late pregnancy, even right before birth-giving. According to MSD Manuals, chloramphenicol should not be given to neonates with younger than 1 month of age with more than a dose of 25 mg/kg/day to start with. The serum concentration of the medication should be monitored to titrate to a therapeutic level and to prevent toxicity. Medication reconciliation of other medications that neonates may be taking that can decrease blood cell count should be monitored because of this medications ability to suppress bone marrow activity. Rifampicin and trimethoprim are examples of medications with bone marrow suppression abilities and are contraindicated for concomitant use with chloramphenicol. In regards to bone marrow suppression, chloramphenicol has two major etiological manifestations. The first mechanism of bone marrow suppression affects the formation of blood cells such as erythrocytes, and this can be reversible since it is an early sign up toxicity.
As of May 2010, the smallest time interval uncertainty in direct measurements is on the order of 12 attoseconds (1.2 × 10−17 seconds), about 3.7 × 1026 Planck times. Units
The second (s) is the SI base unit. A minute (min) is 60 seconds in length, and an hour is 60 minutes or 3600 seconds in length. A day is usually 24 hours or 86,400 seconds in length; however, the duration of a calendar day can vary due to Daylight saving time and Leap seconds. Definitions and standards
A time standard is a specification for measuring time: assigning a number or calendar date to an instant (point in time), quantifying the duration of a time interval, and establishing a chronology (ordering of events). In modern times, several time specifications have been officially recognized as standards, where formerly they were matters of custom and practice. The invention in 1955 of the caesium atomic clock has led to the replacement of older and purely astronomical time standards such as sidereal time and ephemeris time, for most practical purposes, by newer time standards based wholly or partly on atomic time using the SI second. International Atomic Time (TAI) is the primary international time standard from which other time standards are calculated. Universal Time (UT1) is mean solar time at 0° longitude, computed from astronomical observations. It varies from TAI because of the irregularities in Earths rotation. Coordinated Universal Time (UTC) is an atomic time scale designed to approximate Universal Time. UTC differs from TAI by an integral number of seconds.