Blood Concentration of Plasticizer at Steady-State in Dialysing Patients: A Model

Morphine, pethidine and fentanyl have similar pharmacokinetic profiles with moderately long elimination half-lives (3 to 4 hours), large steady-state volumes of distribution (2 to 4 l/kg), and high hepatic clearances (10 to 20 ml/kg/min). Alfentanil has a shorter terminal elimination half-life (1 1/2 hours) because of a decreased steady-state volume of distribution (0.5 to 1 l/kg). Physicochemical properties and blood: brain tissue solubility can explain the clinical differences in the rate of onset and dissipation of narcotic effect for these four narcotics. Morphine's low lipid solubility and limited rate of blood: brain barrier penetration results in the slow onset and dissipation of narcotic effect relative to pethidine or fentanyl. Alfentanil's lower blood: brain solubility results in the very rapid onset of narcotic effect when compared to fentanyl. All of the narcotics have a very steep blood concentration: narcotic effect curves. Thus, small changes of narcotic blood concentrations can have profound changes of narcotic effect. Finally, different degrees of perioperative stimuli result in different narcotic blood concentration requirements. Thus, narcotic infusion rates need be varied during surgical procedures to adjust for the varying opiate requirement.

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Studies on Water in the Hydration Chamber of a Modified Electron Microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100069715 ◽

1970 ◽

Vol 28 ◽

pp. 544-545

Author(s):

R. C. Moretz ◽

G. G. Hausner ◽

D. F. Parsons

Keyword(s):

Thin Film ◽

Thin Films ◽

Electron Microscope ◽

Steady State ◽

Room Temperature ◽

Small Mass ◽

Equilibrium Pressure ◽

Biological Objects ◽

Mechanical Pump ◽

Differential Pumping

Use of the electron microscope to examine wet objects is possible due to the small mass thickness of the equilibrium pressure of water vapor at room temperature. Previous attempts to examine hydrated biological objects and water itself used a chamber consisting of two small apertures sealed by two thin films. Extensive work in our laboratory showed that such films have an 80% failure rate when wet. Using the principle of differential pumping of the microscope column, we can use open apertures in place of thin film windows.Fig. 1 shows the modified Siemens la specimen chamber with the connections to the water supply and the auxiliary pumping station. A mechanical pump is connected to the vapor supply via a 100μ aperture to maintain steady-state conditions.

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Continuous hydrogenolysis of acetal-stabilized lignin in flow

Green Chemistry ◽

10.1039/d0gc02928a ◽

2021 ◽

Author(s):

Wu Lan ◽

Yuan Peng Du ◽

Songlan Sun ◽

Jean Behaghel de Bueren ◽

Florent Héroguel ◽

...

Keyword(s):

Steady State ◽

Challenges And Opportunities

We performed a steady state high-yielding depolymerization of soluble acetal-stabilized lignin in flow, which offered a window into challenges and opportunities that will be faced when continuously processing this feedstock.

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