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Morgan CG, Bisby RH, Johnson SA, Mitchell AC. Fast solute release from photosensitive liposomes: an alternative to 'caged' reagents for use in biological systems. FEBS Lett 1995; 375:113-6. [PMID: 7498457 DOI: 10.1016/0014-5793(95)01193-i] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The kinetics of release of soluble marker trapped in liposomes of gel phase phospholipid containing a photoisomerisable phospholipid analogue have been investigated. Marker release is triggered by UV laser flash photolysis at 355 nm. A markedly temperature-dependent release rate is seen, and above 25 degrees C millisecond release kinetics can be achieved. These results suggest that such liposomes might find application as an alternative to conventional 'caged' reagents for photo-triggered reagent release in biological research.
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Morgan CG, Yianni YP, Sandhu SS, Mitchell AC. Liposome fusion and lipid exchange on ultraviolet irradiation of liposomes containing a photochromic phospholipid. Photochem Photobiol 1995; 62:24-9. [PMID: 7638269 DOI: 10.1111/j.1751-1097.1995.tb05233.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A photochromic phospholipid, 1,2-bis[4-4(4-n-butylphenylazo) phenylbutyroyl] phosphatidylcholine (Bis-Azo PC) has been incorporated into liposomes of gel- and liquid-crystalline- phase phospholipids. Liposomes of gel-phase phospholipid are stable in the presence of the trans photostationary state Bis-Azo PC and can encapsulate fluorescent marker dye. On photoisomerization to the cis photostationary state, trapped marker is rapidly released. Liposomes containing Bis-Azo PC can rapidly fuse together after UV isomerization, this process continuing in the dark. Exposure to white light causes reversion of Bis-Azo Pc to the trans form and halts dye leakage and vesicle fusion. Both unilamellar and multilamellar liposomes are able to fuse together on UV exposure. On UV photolysis, liposomes containing Bis-Azo PC do not fuse with a large excess of unlabeled liposomes, but transfer of Bis-Azo PC can be demonstrated spectrophotometrically. Vesicles of pure gel-phase lipid containing trapped marker dye but initially no Bis-Azo PC become leaky as a result of this lipid transfer. Liposomes composed of liquid-crystalline-phase phosphatidylcholine- containing Bis-Azo PC neither leak trapped marker no fuse together on photolysis, nor do liquid-crystalline-phase liposomes fuse with gel-phase liposomes under these conditions. These results are discussed together with some possible applications of liposome photodestabilization.
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Abstract
Recent legislation such as the Americans with Disabilities Act will have a significant impact on higher education in nursing. A survey was conducted to describe the extent to which BSN and ADN nursing programs in the United States admit and graduate special needs and chronically ill students, and to identify the accommodations which have been successful in providing nursing education to these students. Responses received from 86 schools of nursing in 44 states indicated that most schools have had contact with students with special needs such as visual, hearing, or mobility impairments, learning disabilities, and mental or chronic illnesses. Learning disabilities and mental impairment were cited most frequently as having been present among the student population. Few programs have had experience with students with vision problems. While most programs responding had little experience with providing special accommodations to special needs students, most were aware of accessibility on their campuses. Recent legislation aimed at creating opportunities for disabled individuals to successfully enter the work force creates challenges for schools of nursing in education of students with special needs. Issues are raised that must be addressed to meet this important challenge.
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Nellis WJ, Mitchell AC, McCandless PC, Erskine DJ, Weir ST. Electronic energy gap of molecular hydrogen from electrical conductivity measurements at high shock pressures. PHYSICAL REVIEW LETTERS 1992; 68:2937-2940. [PMID: 10045533 DOI: 10.1103/physrevlett.68.2937] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Nellis WJ, Mitchell AC, Ree FH, Ross M, Holmes NC, Trainor RJ, Erskine DJ. Equation of state of shock‐compressed liquids: Carbon dioxide and air. J Chem Phys 1991. [DOI: 10.1063/1.461665] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Nellis WJ, Radousky HB, Hamilton DC, Mitchell AC, Holmes NC, Christianson KB, van Thiel M. Equation‐of‐state, shock‐temperature, and electrical‐conductivity data of dense fluid nitrogen in the region of the dissociative phase transition. J Chem Phys 1991. [DOI: 10.1063/1.459895] [Citation(s) in RCA: 101] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Radousky HB, Mitchell AC, Nellis WJ. Shock temperature measurements of planetary ices: NH3, CH4, and ‘‘synthetic Uranus’’. J Chem Phys 1990. [DOI: 10.1063/1.459302] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Hamilton DC, Mitchell AC, Ree FH, Nellis WJ. Equation of state of 1‐butene shocked to 54 GPa (540 kbar). J Chem Phys 1988. [DOI: 10.1063/1.454284] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Nellis WJ, Hamilton DC, Holmes NC, Radousky HB, Ree FH, Mitchell AC, Nicol M. The Nature of the Interior of Uranus Based on Studies of Planetary Ices at High Dynamic Pressure. Science 1988; 240:779-81. [PMID: 17741451 DOI: 10.1126/science.240.4853.779] [Citation(s) in RCA: 92] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Data from the Voyager II spacecraft showed that Uranus has a large magnetic field with geometry similar to an offset tilted dipole. To interpret the origin of the magnetic field, measurements were made of electrical conductivity and equation-of-state data of the planetary "ices" ammonia, methane, and "synthetic Uranus" at shock pressures and temperatures up to 75 gigapascals and 5000 K. These pressures and temperatures correspond to conditions at the depths at which the surface magnetic field is generated. Above 40 gigapascals the conductivities of synthetic Uranus, water, and ammonia plateau at about 20(ohm-cm)(-1), providing an upper limit for the electrical conductivity used in kinematic or dynamo calculations. The nature of materials at the extreme conditions in the interior is discussed.
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Hamilton DC, Nellis WJ, Mitchell AC, Ree FH, van Thiel M. Electrical conductivity and equation of state of shock‐compressed liquid oxygen. J Chem Phys 1988. [DOI: 10.1063/1.454657] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Nellis WJ, Moriarty JA, Mitchell AC, Ross M, Dandrea RG, Ashcroft NW, Holmes NC, Gathers GR. Metals physics at ultrahigh pressure: Aluminum, copper, and lead as prototypes. PHYSICAL REVIEW LETTERS 1988; 60:1414-1417. [PMID: 10038032 DOI: 10.1103/physrevlett.60.1414] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Morgan CG, Thomas EW, Sandhu SS, Yianni YP, Mitchell AC. Light-induced fusion of liposomes with release of trapped marker dye is sensitised by photochromic phospholipid. BIOCHIMICA ET BIOPHYSICA ACTA 1987; 903:504-9. [PMID: 3663656 DOI: 10.1016/0005-2736(87)90057-5] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Liposomes have been prepared from dipalmitoylphosphatidylcholine containing small amounts of a synthetic photochromic phospholipid, 'Bis-Azo PC'. In the dark, these are stable at room temperature, and contents do not significantly leak over weeks. Photoisomerisation results in immediate release of trapped marker, and in liposome fusion to form larger structures. Fusion has been detected using a fluorescence polarisation assay, and confirmed by electron microscopy. In mixtures, fusion occurs between 'photochromic' liposomes and those of pure lipid. Bis-Azo PC contains two photochromic acyl chains; analogues bearing a single photochromic chain appear to have little effect on bilayer permeability after isomerisation. Photo-induced leakage and liposome fusion suggest possible applications for localised drug delivery as an adjunct to phototherapy. The ability to non-invasively trigger fusion processes should be useful in fundamental studies of membrane interactions. We believe this to be the first report of photo-induced fusion to date.
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Radousky HB, Nellis WJ, Ross M, Hamilton DC, Mitchell AC. Molecular dissociation and shock-induced cooling in fluid nitrogen at high densities and temperatures. PHYSICAL REVIEW LETTERS 1986; 57:2419-2422. [PMID: 10033720 DOI: 10.1103/physrevlett.57.2419] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Radousky HB, Ross M, Mitchell AC, Nellis WJ. Shock temperatures and melting in CsI. PHYSICAL REVIEW. B, CONDENSED MATTER 1985; 31:1457-1462. [PMID: 9935920 DOI: 10.1103/physrevb.31.1457] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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Nellis WJ, Ree FH, Trainor RJ, Mitchell AC, Boslough MB. Equation of state and optical luminosity of benzene, polybutene, and polyethylene shocked to 210 GPa (2.1 Mbar). J Chem Phys 1984. [DOI: 10.1063/1.447027] [Citation(s) in RCA: 94] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Elliott RV, Mitchell AC. Foundation report. New guidelines for chronic pain management. COLORADO MEDICINE 1983; 80:307-10. [PMID: 6197224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Nellis WJ, Mitchell AC, van Thiel M, Devine GJ, Trainor RJ, Brown N. Equation‐of‐state data for molecular hydrogen and deuterium at shock pressures in the range 2–76 GPa (20–760 kbar)a). J Chem Phys 1983. [DOI: 10.1063/1.445938] [Citation(s) in RCA: 214] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Mitchell AC. The hospital medical staff--1983. COLORADO MEDICINE 1983; 80:188-90. [PMID: 6627856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Mitchell AC, Nellis WJ. Equation of state and electrical conductivity of water and ammonia shocked to the 100 GPa (1 Mbar) pressure range. J Chem Phys 1982. [DOI: 10.1063/1.443030] [Citation(s) in RCA: 219] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Lyzenga GA, Ahrens TJ, Nellis WJ, Mitchell AC. The temperature of shock‐compressed water. J Chem Phys 1982. [DOI: 10.1063/1.443031] [Citation(s) in RCA: 152] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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47
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Nellis WJ, Ree FH, van Thiel M, Mitchell AC. Shock compression of liquid carbon monoxide and methane to 90 GPa (900 kbar). J Chem Phys 1981. [DOI: 10.1063/1.442401] [Citation(s) in RCA: 118] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Nellis WJ, Mitchell AC. Shock compression of liquid argon, nitrogen, and oxygen to 90 GPa (900 kbar). J Chem Phys 1980. [DOI: 10.1063/1.440105] [Citation(s) in RCA: 162] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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49
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Mitchell AC. Barriers to therapeutic communication with black clients. Nurs Outlook 1978; 26:109-12. [PMID: 245615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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