151
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Abstract
The hypothesis that endogenous cholecystokinin (CCK) released from the small intestine during feeding causes satiety was tested in rat pups, 9 to 12 days old. Intragastric administration of soybean trypsin inhibitor, a procedure that releases CCK from the small intestine, decreased the subsequent intake of a test meal. This effect was reversed by prior treatment with MK-329, a selective antagonist of CCK at alimentary-type CCK (CCK-A) receptors. Thus, endogenous, small intestinal CCK can cause satiety in the neonatal rat and this effect involves CCK-A receptors.
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152
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Abstract
Low doses (0.12-2.0 micrograms/kg) of cholecystokinin octapeptide (CCK), administered intraperitoneally, support the formation of conditioned odor preference in neonatal and weanling rats. Exposure to a novel odor was paired with CCK injection, and the rats' olfactory choices were assessed 24 hr later. Rats at 5, 11, and 22 days of age preferred the odor previously associated with CCK, compared with vehicle-injected littermates. In contrast, CCK failed to support olfactory conditioning in 28-day-old rats, whether they were (a) weaned and independently housed, (b) residing with the dam and suckling, or (c) fed only milk. Adult rats also did not establish an odor preference with CCK as the unconditioned stimulus. Thus, CCK's changing impact from positive to neutral probably occurs during the rats' 4th postnatal week and may be related to maturational changes occurring during the final stages of weaning.
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153
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Abstract
Low doses (0.12-2.0 micrograms/kg) of cholecystokinin octapeptide (CCK), administered intraperitoneally, support the formation of conditioned odor preference in neonatal and weanling rats. Exposure to a novel odor was paired with CCK injection, and the rats' olfactory choices were assessed 24 hr later. Rats at 5, 11, and 22 days of age preferred the odor previously associated with CCK, compared with vehicle-injected littermates. In contrast, CCK failed to support olfactory conditioning in 28-day-old rats, whether they were (a) weaned and independently housed, (b) residing with the dam and suckling, or (c) fed only milk. Adult rats also did not establish an odor preference with CCK as the unconditioned stimulus. Thus, CCK's changing impact from positive to neutral probably occurs during the rats' 4th postnatal week and may be related to maturational changes occurring during the final stages of weaning.
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154
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Blass EM, Fillion TJ, Weller A, Brunson L. Separation of opioid from nonopioid mediation of affect in neonatal rats: Nonopioid mechanisms mediate maternal contact influences. Behav Neurosci 1990; 104:625-36. [PMID: 2169762 DOI: 10.1037/0735-7044.104.4.625] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A causal distinction is established in infant Norway rats between opioid- and nonopioid-mediated determinants of behavior. Contact influences are shown to be mediated by nonopioid pathways, whereas gustatory influences are shown to be opioid mediated. Specifically, naltrexone (0.5 and 1.0 mg/kg) did not at all diminish quieting exerted by contact with an anesthetized dam but completely reversed the quieting effects of morphine in isolated rats. Naloxone (5 mg/kg) did not affect the latencies with which nondeprived or 8-hr deprived rats 9, 12, 15, and 18 days of age attached to the nipples of anesthetized dams, nor did naloxone (5 and 10 mg/kg) cause any systematic change in nipple attachment in 10- and 18-day-old rats that had been deprived of their dam for either 0, 8, or 24 hr. In a 3rd experiment, naloxone (5 mg/kg) did not significantly reduce milk intake by 9-, 12-, 15-, or 18-day-old rats from the nipple when milk letdown was induced by oxytocin. Moreover, naloxone (5 and 10 mg/kg) did not reduce milk intake in Day-10 rats that, while suckling, received milk via a cannula placed in the posterior portion of the tongue at the level of the intermolar eminence or in rats that obtained milk directly from their awake mother. In contrast, milk intake was significantly reduced by naltrexone (0.25-1.0 mg/kg) in Day-10 rats that obtained milk (a) by licking it off a saturated substrate or (b) through an indwelling cannula located in the anterior portion of the lower jaw. (Milk delivered at this placement is thought to engage feeding systems by its taste and texture.) In a final set of experiments in Day-10 rats, intake of milk delivered via anterior jaw cannulae was reduced by naloxone (5 and 10 mg/kg) in rats that were either isolated, in contact with an anesthetized dam, or attached to her nipples. On the basis of resistance to naloxone and naltrexone administration, these experiments demonstrate that behavioral influences of the tactile (and possibly olfactory) qualities of the mother are not mediated by opioid systems. Implications for understanding the means through which mothers can influence their young and the infantile mediators of these maternal influences are discussed.
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155
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Blass EM, Shide DJ, Weller A. Stress-reducing effects of ingesting milk, sugars, and fats. A developmental perspective. Ann N Y Acad Sci 1989; 575:292-305; discussion 305-6. [PMID: 2699193 DOI: 10.1111/j.1749-6632.1989.tb53251.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A developmental approach to the study of feeding is proposed that considers social complexity and its biological mediation as core determinants of later ingestive patterns. Evidence is presented for opioid-mediated influences of milk and its major constituents and for nonopioid-mediated channels for contact comfort. Consideration of these factors might help us better understand some of the determinants of human feeding disorders such as bulimia and anorexia nervosa.
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156
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Rebmann H, Weller A. [Nursery schools, a site for exposure to house dust mite allergens?]. Monatsschr Kinderheilkd 1989; 137:672-4. [PMID: 2586533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In June 1988, 110 dust samples from carpets, cushions, mattresses and upholstered furniture were collected by vacuum cleaner in 33 municipal nursery schools. All samples were assessed with guanine test strips (Acarex). In all samples giving moderately or strongly positive results in these tests (guanine stages 2 and 3) and in 10 random samples each from of stages 1 (weakly positive) and 0 (negative), mites were counted by light microscope. In 36% of the nursery schools, objects with guanine stages 2 or 3 were found, which indicates a high allergen burden. The high guanine stages were found only in mattresses, cushions and upholstered furniture. Nursery schools can be source areas of significant allergen exposure relevant for children with dust mite allergies.
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157
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Lonsky C, Thomas P, Weller A. Optical dephasing in disordered semiconductors. PHYSICAL REVIEW LETTERS 1989; 63:652-655. [PMID: 10041137 DOI: 10.1103/physrevlett.63.652] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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158
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Weller A, Thomas P, Feldmann J, Peter G, G�bel EO. Model calculations of diffusion limited trapping dynamics in quantum well laser structures. ACTA ACUST UNITED AC 1989. [DOI: 10.1007/bf00617851] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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159
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Leslie K, Blay R, Haisch C, Lodge A, Weller A, Huber S. Clinical and experimental aspects of viral myocarditis. Clin Microbiol Rev 1989; 2:191-203. [PMID: 2650861 PMCID: PMC358110 DOI: 10.1128/cmr.2.2.191] [Citation(s) in RCA: 86] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Picornaviruses are frequently implicated as the etiological agents of acute myocarditis. This association is based historically on serological evidence of rising antibody titers to specific pathogens and more recently on identification of viral genomic material in endocardial biopsy specimens through in situ hybridization. Only rarely is infectious virus isolated from either the patient or the heart during periods of maximum myocardial inflammation and injury. Thus, despite a probable viral etiology, much interest centers on the role of the immune system in cardiac damage and the likelihood that the infection triggers an autoimmune response to heart-specific antigens. Heart-reactive antibodies and T cells are found in most myocarditis patients, and immunosuppressive therapy has proven beneficial in many, though not all, cases. Furthermore, murine models of coxsackievirus group B type 3-induced myocarditis also demonstrate that virus infection initiates autoimmunity and that these autoimmune effectors are predominately responsible for tissue injury. How virus-host interactions overcome presumed self-tolerance to heart antigens is discussed, and evidence supporting various theories of virus-initiated autoimmunity and disease pathogenesis are delineated.
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160
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Vetterli D, Boeglin W, Egelhof P, Henneck R, Jaskòla M, Klein A, Mühry H, Plattner GR, Sick I, Trautmann D, Baur G, Weller A. Effects of vacuum polarization in hadron-hadron scattering. PHYSICAL REVIEW LETTERS 1989; 62:1453-1456. [PMID: 10039678 DOI: 10.1103/physrevlett.62.1453] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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161
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Staerk H, Busmann HG, Kühnle W, Weller A. Solvent effects on the magnetic-field-dependent reaction yields of photogenerated radical ion pairs. Chem Phys Lett 1989. [DOI: 10.1016/0009-2614(89)87481-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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162
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Weller A, Blass EM. Behavioral evidence for cholecystokinin-opiate interactions in neonatal rats. THE AMERICAN JOURNAL OF PHYSIOLOGY 1988; 255:R901-7. [PMID: 3202224 DOI: 10.1152/ajpregu.1988.255.6.r901] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
In adult mammals, cholecystokinin (CCK)-opiate interactions are complex and task dependent. Specifically, CCK antagonizes opiate effects in some cases, yet acts similarly to opiate agonists in others. The present study used behavioral measures to determine how CCK interacts with opiates in neonatal rats. CCK, at doses of 1 microgram/kg and higher, markedly reduced isolation-induced distress vocalization in rat pups. Moreover, CCK selectively prevented naltrexone antagonism of opiate-mediated reduction in distress vocalization in 3- and 11-day-old rats. Yet CCK did not affect opiate-induced analgesia, as measured by the hot-plate paw-lift response. Thus CCK either did not interact with opiates or did so agonistically, with the same (low) dose range, and within subjects. These findings suggest independence of stress and pain systems in neonatal rats and demonstrate a functional interaction between CCK and opioid systems.
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163
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Huber SA, Weller A, Herzum M, Lodge PA, Estrin M, Simpson K, Guthrie M. Immunopathogenic mechanisms in experimental picornavirus-induced autoimmunity. PATHOLOGY AND IMMUNOPATHOLOGY RESEARCH 1988; 7:279-91. [PMID: 2853346 DOI: 10.1159/000157123] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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164
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Weller A, Glaubman H, Yehuda S, Caspy T, Ben-Uria Y. Acute and repeated gestational stress affect offspring learning and activity in rats. Physiol Behav 1988; 43:139-43. [PMID: 3212048 DOI: 10.1016/0031-9384(88)90229-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
This study assessed possible long-lasting effects of mild, indirect prenatal stress upon offspring. Dams were restrained for 30 minutes either once or four times during the third trimester of gestation. Their male offspring were challenged in adulthood with a series of appetitive operant learning tasks. Both acute and repeated prenatal maternal restraint retarded the performance of the offspring in a selective manner: deficits appeared during the reversal stage of an operant discrimination task, with no effect on acquisition, discrimination or extinction. Repeated, but not acute, maternal stress was also associated with offspring hyperactivity. This highlights the differential impact of varying the stress schedule. Furthermore, use of multiple measures of learning uncovered a long-lasting, selective effect of relatively mild, indirect prenatal manipulation.
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165
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Weller A, Cheetham AD, Edwards AW, Gill RD, Gondhalekar A, Granetz RS, Snipes J, Wesson JA. Persistent density perturbations at rational-q surfaces following pellet injection in the Joint European Torus. PHYSICAL REVIEW LETTERS 1987; 59:2303-2306. [PMID: 10035508 DOI: 10.1103/physrevlett.59.2303] [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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166
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Weller A, Meek J, Adamson ED. Preparation and properties of monoclonal and polyclonal antibodies to mouse epidermal growth factor (EGF) receptors: evidence for cryptic EGF receptors in embryonal carcinoma cells. Development 1987; 100:351-63. [PMID: 3308402 DOI: 10.1242/dev.100.2.351] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Monoclonal antibodies to mouse epidermal growth factor (EGF) receptor were prepared by the immunization of rats with receptor glycoprotein purified from mouse liver by affinity chromatography on immobilized EGF. Purified mouse EGF receptor retained EGF-inducible autophosphorylating activity and was antigenic in rats and rabbits. The monoclonal antibodies cross react very poorly with human EGF receptor, while polyclonal rabbit antibodies immunoprecipitate human, rat and mouse EGF receptor equally well. The rabbit antibody blocks EGF binding to mouse fibroblast cells and, at 20-fold higher concentrations, stimulates uptake of tritiated thymidine into DNA. This indicates that antibodies bind at or close to the EGF-binding site and can mimic the effects of the growth factor. None of the monoclonals bind at the EGF site of the receptor. Immunoprecipitation, immunoblotting, 125I-EGF cross linking, 125I-surface labelling, immunohistochemistry and autophosphorylation techniques were used to delineate the basis for the induction of EGF receptors when OC15 embryonal carcinoma (EC) cells differentiate into endodermal derivatives (END). EGF-stimulated autophosphorylation of a 170 X 10(3) Mr protein in solubilized OC15 EC cells is readily detectable, although intact EC cells do not bind or respond to EGF by all other tests. The results suggest that cryptic EGF receptors are present in EC stem cells, a finding with implications in development.
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167
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Butsch R, Jänsch H, Krämer D, Möbius K, Moroz Z, Ott W, Rusek K, Steffens E, Suntz R, Tungate G, Turkiewicz I, Weller A, Becker K, Blatt K, Fick D, Leucker H, Luck W, Paul P. Subbarrier fusion with aligned 23Na ions. PHYSICAL REVIEW LETTERS 1986; 57:2002-2005. [PMID: 10033607 DOI: 10.1103/physrevlett.57.2002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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168
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Blatt K, Becker K, Heck B, Jänsch H, Leucker H, Fick D, Caplar R, Butsch R, Krämer D, Möbius K, Moroz Z, Ott W, Paul P, Steffens E, Tungate G, Turkiewicz IM, Weller A. Limitation of heavy-ion fusion: Fusion of aligned 23Na with 23Na. PHYSICAL REVIEW LETTERS 1986; 57:819-822. [PMID: 10034169 DOI: 10.1103/physrevlett.57.819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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169
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Edwards AW, Campbell DJ, Engelhardt WW, Fahrbach H, Gill RD, Granetz RS, Tsuji S, Tubbing BJ, Weller A, Wesson J, Zasche D. Rapid collapse of a plasma sawtooth oscillation in the JET tokamak. PHYSICAL REVIEW LETTERS 1986; 57:210-213. [PMID: 10033749 DOI: 10.1103/physrevlett.57.210] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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170
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Mossman BT, Marsh JP, Hardwick D, Gilbert R, Hill S, Sesko A, Shatos M, Doherty J, Weller A, Bergeron M. Approaches to prevention of asbestos-induced lung disease using polyethylene glycol (PEG)-conjugated catalase. JOURNAL OF FREE RADICALS IN BIOLOGY & MEDICINE 1986; 2:335-8. [PMID: 3036929 DOI: 10.1016/s0748-5514(86)80033-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Asbestos-associated damage to cells of the respiratory tract in vitro can be prevented by the simultaneous addition of scavengers of active oxygen species to cultures. To determine if administration of scavenger enzymes to animals and humans is a plausible approach to the prevention of asbestos-induced lung disease, osmotic pumps were filled with various concentrations of PEG-coupled catalase and implanted subcutaneously into Fischer 344 rats over a 28-day period. At 3, 14, and 28 days after implantation of the pumps, the animals were evaluated for levels of catalase in serum and lung. In addition, lung tissue and lavage fluids were examined at 28 days for biochemical and morphologic indications of cell injury, inflammation, and fibrotic lung disease. At all time points examined, the administration of PEG-catalase caused a dosage-dependent increase in serum levels of catalase. The levels of lung catalase were evaluated at 28 days but not at earlier time periods. In comparison to control rats, the amounts of enzymes (lactic dehydrogenase, alkaline phosphatase), protein, and cells in lavage fluids from treated animals were unaltered. Moreover, the lungs showed no evidence of inflammation or fibrotic disease as determined by differential cell counts in lavage and measurement of hydroxyproline. These studies suggest that administration of PEG-catalase does not cause injury or other alterations in lung tissue and can be pursued as a feasible approach to prevention of asbestosis.
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171
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Weller A, Egelhof P, Caplar R, Karban O, Krämer D, Möbius K, Moroz Z, Rusek K, Steffens E, Tungate G, Blatt K, Koenig I, Fick D. Electromagnetic excitation of aligned 7Li nuclei. PHYSICAL REVIEW LETTERS 1985; 55:480-483. [PMID: 10032364 DOI: 10.1103/physrevlett.55.480] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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172
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Staerk H, Kühnle W, Treichel R, Weller A. Magnetic field dependence of intramolecular exciplex formation in polymethyelene-linked A–D systems. Chem Phys Lett 1985. [DOI: 10.1016/0009-2614(85)85257-x] [Citation(s) in RCA: 101] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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173
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Krämer D, Becker K, Blatt K, Čaplar R, Fick D, Gemmeke H, Haeberli W, Jänsch H, Karban O, Koenig I, Luh L, Möbius KH, Nečas V, Ott W, Tanaka M, Tungate G, Turkiewicz I, Weller A, Steffens E. The source of polarized heavy ions (PSI) at the Heidelberg MP tandem. ACTA ACUST UNITED AC 1984. [DOI: 10.1016/0167-5087(84)90422-8] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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174
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Weller A. Blood bankers send out AIDS alert. PATHOLOGIST 1983; 37:431-2. [PMID: 10263494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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175
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Weller A, Nolting F, Staerk H. A quantitative interpretation of the magnetic field effect on hyperfine-coupling-induced triplet fromation from radical ion pairs. Chem Phys Lett 1983. [DOI: 10.1016/0009-2614(83)80109-2] [Citation(s) in RCA: 164] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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176
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Staerk H, Treichel R, Weller A. Life uncertainty broadening in photoinduced electron transfer. Chem Phys Lett 1983. [DOI: 10.1016/0009-2614(83)80110-9] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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177
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Weller A. DHHS + DRG = prospective reimbursement. PATHOLOGIST 1982; 36:646-7. [PMID: 10310094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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178
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Weller A. CAP to FDA: Class II unnecessary for most of 175 devices. PATHOLOGIST 1982; 36:597-9. [PMID: 10257232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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179
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Weber A, Mommsen H, Sarter W, Weller A. Double scattering in Rutherford backscattering spectra. ACTA ACUST UNITED AC 1982. [DOI: 10.1016/0167-5087(82)90295-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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180
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181
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Greinert R, Staerk H, Stier A, Weller A. E-type delayed fluorescence depolarization, technique to probe rotational motion in the microsecond range. JOURNAL OF BIOCHEMICAL AND BIOPHYSICAL METHODS 1979; 1:77-83. [PMID: 95189 DOI: 10.1016/0165-022x(79)90014-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
E (eosin)-type delayed fluorescence depolarization studies extend the time range for the measurement of rotational diffusion to microseconds and ms, thereby allowing investigation of slow rotational movement of macromolecules like membrane proteins. An apparatus is described for the determination of time-dependent anisotropy in this interesting time range. The method has been tested on eosin-labelled cytochrome P-450 incorporated into phospholipid membrane vesicles.
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182
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Abstract
Photoinduced electron transfer generates radical pairs which recombine with 10(-9)10(-8)s by electron back-transfer to either singlet or triplet products. The product distribution determined by the spin motion of the unpaired electrons in the radical pairs is affected by external magnetic fields. The analysis of the magnetic field effect furnishes new information about electron transfer processes. Light-induced electron transfer in polar solvents and in the bacterial photosynthetic reaction center are discussed as examples.
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183
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Werner HJ, Schulten K, Weller A. Electron transfer and spin exchange contributing to the magnetic field dependence of the primary photochemical reaction of bacterial photosynthesis. BIOCHIMICA ET BIOPHYSICA ACTA 1978; 502:255-68. [PMID: 306834 DOI: 10.1016/0005-2728(78)90047-6] [Citation(s) in RCA: 111] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The yield phiT of triplet products "PR" generated in reaction centers of Rhodopseudomonas sphaeroides in which the "primary" acceptor is reduced had been found to depend on external magnetic fields. The magnetic field dependence varies, however, between different reaction center preparations. By means of a theoretical description of the primary electron transfer processes and hyperfine coupling-induced electron spin motion the factors influencing the magnetic field behaviour of the triplet products are studied. The following quantities characteristic of the primary electron transfer in photosynthesis have a strong effect on phiT: (1) the rate constants of reversible electron transfer between the initially excited singlet state of the reaction center and an intermediate radical ion pair state; (2) the rate constants of irreversible electron transfer of the radical pair to the ground and excited triplet state of the reaction center; (3) the electron exchange interactions between the radical pair and the "primary" acceptor. From the observed magnetic field dependence of phiT estimates for these quantities are obtained. A temperature dependence of the magnetic field behaviour of phiT and a magnetic field effect on the fluorescence quantum yield of the reaction center are predicted.
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184
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Pollmann P, Rehm D, Weller A. Der Druckeinfluß auf die Bildung von Hetero-Excimeren. 2. Mitt. Verschiedene Donor-Akzentor-Systeme in n-Hexan. Colloid Polym Sci 1978. [DOI: 10.1007/bf01746697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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185
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Abstract
The excited acid-base
reactions of 1-naphthol and pyren-1-amine have been studied in sodium dodecyl
sulphate surfactant micelles. These molecules which show complete equilibration
for excited state reactions in water show only partial equilibration in micelles
(2-naphthol goes from partial equilibration to complete lack of reaction). It
is believed that this is a micellar viscosity effect.
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186
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Schulten K, Staerk H, Weller A, Werner HJ, Nickel B. Magnetic Field Dependence of the Geminate Recombination of Radical Ion Pairs in Polar Solvents. ACTA ACUST UNITED AC 1976. [DOI: 10.1524/zpch.1976.101.1-6.371] [Citation(s) in RCA: 266] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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187
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Breuninger V, Weller A. On the mechanisms of phosphorescence quenching by transition metal ions. Chem Phys Lett 1973. [DOI: 10.1016/0009-2614(73)89559-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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188
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Weller A. Biting the hand. DENTAL MANAGEMENT 1972; 12:95-6. [PMID: 4507366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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189
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Potashnik R, Goldschmidt CR, Ottolenghi M, Weller A. Absorption Spectra of Exciplexes. J Chem Phys 1971. [DOI: 10.1063/1.1675677] [Citation(s) in RCA: 41] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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190
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191
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Weller A, Zachariasse K. Chemiluminescence from radical ion recombination. Experimental evidence for triplet—triplet annihilation mechanism. Chem Phys Lett 1971. [DOI: 10.1016/0009-2614(71)80459-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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192
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Beens H, Möhwald H, Rehm D, Sackmann E, Weller A. Fluorescence polarization studies of hetero-excimers oriented in liquid crystals. Chem Phys Lett 1971. [DOI: 10.1016/0009-2614(71)80058-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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193
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Nickel B, Staerk H, Weller A. Energy transfer from adsorbed dye molecules to anthracene single crystals. Chem Phys Lett 1969. [DOI: 10.1016/0009-2614(69)85025-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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194
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Weller A. Optische Anregung organischer Systeme. Z PHYS CHEM 1969. [DOI: 10.1524/zpch.1969.63.5_6.326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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195
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Weller A. Triplets at Buchanan Hospital, St. Leonards-on-Sea. MIDWIVES CHRONICLE 1969; 82:14-5. [PMID: 5190144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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196
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197
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Weller A. Bildung und Eigenschaften von Molekülkomplexen im angeregten Zustand. Angew Chem Int Ed Engl 1968. [DOI: 10.1002/ange.19680800415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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198
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Weller A. Formation and Properties of Molecular Complexes in the Excited State. Angew Chem Int Ed Engl 1968. [DOI: 10.1002/anie.196801471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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199
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200
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Leonhardt H, Weller A. Kinetische Protondonatorwirkung hydratisierter Kationen. Naturwissenschaften 1960. [DOI: 10.1007/bf00708833] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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