Hopkins head

If the compound to be distilled is in solution, it is now necessary to remove the solvent. If the solvent has a boiling point close (within 100°) to that of the compound, it is necessary to effect the removal of the solvent with as much care as is used in the distillation of the compound. If the solvent has a much lower boiling point than the compound, it is convenient to remove it by using a Hopkins head (Fig. 1-14) or a rotating evaporator (Fig. 1-15), usually under... 

The inlet tube for steam should reach to the bottom of the distillation flask. A i6-mm. bulb on the end of this tube with four 0.8-mm. openings helps to insure thorough mixmg of the heavy residue. If this is not well stirred the aldehyde distils very slowly. It is well to connect the flask to the condenser through a large Hopkins still head in order to prevent the entrainment of foam during the distillation. 

From these nine basic quantities, numerous other SI units may be derived. Table B.2 lists a number of these derived units, particularly those relevant to colloid and surface chemistry. The table is arranged alphabetically according to the name of the physical quantity involved. Note that instructions for the use of the conversion factors —depending on the direction of the conversion —are given in the top and bottom headings of the columns. Table B.2 is by no means an exhaustive list of the various derived SI units Hopkins (1973) reports on many additional conversions, as do most handbooks and numerous other references. 

Connections should be of glass since cork and rubber are attacked readily. Since nitrosobenzene decomposes at the elevated temperature, it should be steam-distilled as rapidly as possible. If several runs are made, not more than four or five should be combined for distillation. A Hopkins still head is effective for preventing contamination. 

Hopkins, M. S., Graham, A. W., Hewett, R., Ash, J., and Head, J. (1990). Evidence of late Pleistocene fires and eucalypt forest from a north Queensland humid tropical reainforest site. Aust. I. Ecol. 15, 345-357. 

An alternative approach to studying the migration phenomenon has been adopted by Hopkins Allen (333). These workers severed the scolex of worms (one-worm infections) on day 14, without disturbing the attached scolex from the mucosa. They found that, within 48-72 h, the scolex had moved back to a position where a young worm of that size would normally be found. They suggested that the position of the scolex is, in part, determined by the position of the strobila, which monitors information about its position from all over its surface, balancing the input of adverse information from its tail and head ends (333). They concluded that the preferred site for H. diminuta was 30-50% down the small intestine. 

Dr Neal Halsey, head of the Institute for Vaccine Safety at John Hopkins University, explained that the poor sales had resulted from public misperception and the promotion of false concerns (5). Lyme disease researchers consider the Lyme vaccine story in the USA to have been a setback in Ljme disease prevention. Vaccines meeting the specific epidemiological situation in Europe are under development. Lyme disease prevention and prophylaxis has been reviewed (6). 

Candace Pert, together with Solomon Snyder (Johns Hopkins, Baltimore, USA), first identified opioid receptors in the brain in 1972 (Eignre 1.5). In 1975 Hans Kosterlitz and John Hnghes (Aberdeen, UK) reported the existence of an endogenons morphine-like snbstance and named it enkephalin (for in the head ). Enkephalins, endorphins, and dynorphins bind to specific receptor sites in the brain. 

Mr. Hopkins has been severely depress for several months. Two w ks ago the primary care provider prescribed amitriptyline 30 mg orally four times a day. His family is concerned because he is still depressed. They are requesting that the dosage be increased. Discus what information you would ve Mr. Hopkins and his family and what assessments you could make Ms. ikffermn has been taking phenelzine for depression. Sie reports having a bad headache at the back of her head. Determine what assessmeait would be most important to make. Explain what action, if any, you would... 

Our administrative leaders at Johns Hopkins were skeptical. On February 8, 1979, I received a letter from Dr. Bob Heyssell, Director of Johns Hopkins Hospital (before coming to Johns Hopkins, he had been head of nudear medicine at Vanderbilt University). 

As I lay with my head in the NeuroEcat PET scanner, I was injected with 25 me of C-11 carfenanil, the label on 80 ng kg of the drug. In the room were Jim Frost, Sol Snyder, Jon Links, our chief nuclear medicine technologist, Jim Langan, who had been in nuclear medicine at Johns Hopkins since its inception in 1958, and two other technologists. Jay Rhine and Martin Stumpf... 

Corruccini has prepared an excellent survey of the properties of materials at low temperatures. Included in this survey are data on thermal conductivities, coefficients of linear thermal expansion, and mean thermal expansions of a number of important structural materials obtained by H. L. Laquer and E. L. Head. Figure 15 is a plot of AL/Lq for four metals from data given in the survey paper. Additional data may be found in other compilations by Scott,Bell, and McClin-tock, and in recent articles by Rhodes, Moeller, Hopkins, and Marx, " Robbins, Ohori, and Weitzel, and Zelman on the thermal expansion of a number of metals, elastomers, and organic sealants, respectively. 

Eugene D. Shchukin graduated in physics from Moscow State University (MSU, 1950) and earned a PhD (1958) and a doctor of science (1962) in physics and mathematics. The main positions he has held include the following research professor at Johns Hopkins University (1994-2006) and professor emeritus (since 2006) professor (1967-2002), chairman (1973-1994), distinguished professor (since 1995) at the Colloid Chemistry Department at MSU, Institute of Physical Chemistry of the USSR Academy of Sciences, Head of Laboratory of Physical Chemistry Mechanics (1967-2003), and advisor (since 2003). 

The goals of SodM have not changed over the years. What have changed are the methods used and the emphasis between the different tasks. Its activities can be summarised under four headings, three of which match the steps in figure 2 of Hopkins Hale s introductory chapter to this book (see in brackets below). 

Always trust the little voice in your head. Gemma Hopkins, STS... 

---