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JW Erdman AJ Thatcher NE Hofmann JD Lederman SS Block CM Lee S Mokady 《Canadian Metallurgical Quarterly》1998,128(11):2009-2013
The algae Dunaliella bardawil and Dunaliella salina naturally contain large concentrations of all-trans and 9-cis beta-carotene (betaC). The purpose of this study was to compare the relative serum and tissue accumulation of all-trans and 9-cis betaC in ferrets fed different ratios of all-trans/9-cis betaC derived from two commercial sources, D. bardawil or D. salina (Betatene). Male ferrets (7 wk old) were fed carotene-free, pelleted diets for 27 d. Beginning on d 18, groups of ferrets (n = 6 or 7) received daily, one of six oral supplements varying in ratios of 9-cis and all-trans betaC mixed with approximately 1.0mL of Ensure. Four supplements containing 5.2-8.3 micromol total betaC were prepared from a 20% Betatene preparation, D. bardawil, a high-cis Betatene preparation, and Betatene further enriched in 9-cis betaC with all-trans betaC/9-cis betaC ratios of 2.2, 1.5, 0.6 and 0.4, respectively. Two control supplements, high and low betaC, were prepared from commercial betaC beadlets. The high control supplement had an all-trans/9-cis ratio of 19.0, whereas 9-cis betaC was not detected in the low supplement. On d 27, serum and tissues were obtained for HPLC analysis of betaC and its isomers. Analysis of livers showed that all-trans betaC was the primary isomer present, but 9-cis and other isomers were also detected in all groups. The hepatic all-trans/9-cis ratios were 5.9, 4.9, 2.5, 1.4, 52.2 and47.5, respectively, for the groups listed above. Lower amounts of all-trans and 9-cis betaC were found in kidneys compared with the liver, but ratios of all-trans/9-cis were not different among groups. Only trace amounts of 9-cis betaC were found in serum. These results demonstrate that the algae D. bardawil and D. salina provide a bioavailable source of betaC isomers, but, as in humans, absorption of 9-cis betaC is poor and any 9-cis betaC absorbed is apparently cleared by the liver. 相似文献
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Monroe William S. Skidmore Frank M. Odaibo David G. Tanik Murat M. 《Neural computing & applications》2021,33(11):6027-6038
Neural Computing and Applications - In the medical imaging domain, nonlinear warping has enabled pixel-by-pixel mapping of one image dataset to a reference dataset. This co-registration of data... 相似文献
66.
R. S. Chambers Frank P. Gerstle Jr. S. L. Monroe 《Journal of the American Ceramic Society》1989,72(6):929-932
A family of phosphate glasses has been developed with thermal expansion behavior in the elastic range that nearly matches the response of 304 stainless steel. Attempts to make concentric pin-shell seals consistently have yielded fractures between 400° and 300°C during cooling. Elastic stress analyses which neglect glass transitional behavior and utilize constant glassy ("elastic") thermal expansion coefficients predict a residual stress state that is compressive. However, viscoelastic computations which include the effects of structural relaxation during glass transtion show that tensile stresses sufficient to cause failure arise during cooldown of the seal. 相似文献
67.
This article has made a number of points that assert what is today a minority position within the fields of MPD/DID and BPD. We hope our views will stimulate attempts by others to rethink their positions and test our assertions, so that issues surrounding these two disorders can be sharpened. For the sake of the clarity of future work, we summarize in outline form the essence of our viewpoint. 1. BPD and MPD/DID have similar appearing symptoms, such as identity problems, unstable affect modulation, self-destructive behaviors, chaotic impulse control, and troubled interpersonal relationships, but they have decisive differences in underlying dynamics, process, and structure. 2. DSM tends to blur these two disorders by its emphasis on phenomenology over inner structure, thus fostering misleading conclusions when DSM criteria are used to test for comorbidity or overlap between BPD and MPD/DID. 3. BPD and MPD/DID are both described dynamically as using the defense of splitting, but we contend that the splitting in each disorder is fundamentally different from the splitting in the other. BPD uses a polarization form of splitting, whereas MPD/DID uses ego splitting or identity division. 4. Both disorders partake in the process of dissociation, but the quality of dissociation in BPD is a "low-tech" spaced out type, whereas that of MPD/DID is a "high-tech" waking dream. 5. BPD structure is also "low tech," with polarization of self, object, and relationship. MPD/DID structure is "high tech," with heavily symbolic, highly nuanced variations of self, object, and relationship. 6. Although both conditions have etiologic elements of trauma, BPD has a larger degree of developmental deficiency, with a failure to complete the task of entering a repression hierarchy of defenses. MPD/DID, by use of primary process-linked symbolic dissociation, is able to continue development to the repression hierarchy, although at a profound cost of simultaneous suspension of reality testing. BPD patients suffer from the rigid use of too few defenses; MPD/DID patients suffer from the obsolete use of too many defenses. 7. BPD patients grow up in homes in which overtly expressed aggression is more tolerated, or at least more openly experienced. MPD/DID patients grow up in homes in which the fact of aggression is kept a secret. This has consequences for the formation of psychic structure in each disorder.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
68.
C Frey K Narayanan K McMillan L Spack SS Gross BS Masters OW Griffith 《Canadian Metallurgical Quarterly》1994,269(42):26083-26091
Nitric-oxide synthase (NOS) catalyzes the oxidation of L-arginine to citrulline and nitric oxide (NO). The enzyme is inhibited by a variety of N omega-monosubstituted L-arginine analogs, and some of these compounds are useful in reversing pathologies associated with the overproduction of NO (e.g. the hypotension of septic shock). We report here that L-thiocitrulline (gamma-thioureido-L-norvaline) is a potent, stereospecific inhibitor of the constitutive brain and endothelial isoforms of NOS as well as the isoform induced in vascular smooth muscle cells by lipopolysaccharide and interferon-gamma. Steady state kinetic studies show L-thiocitrulline inhibition is competitive with L-arginine (Ki approximately 4-20% of KArgm), indicating that initial binding is as a substrate/product analog. In contrast to L-arginine and N omega-methyl-L-arginine, the prototypic NOS inhibitor, L-thiocitrulline binding elicits a "Type II" difference spectrum, indicating a high spin to low spin transition of the iron in the heme cofactor. This finding suggests that L-thiocitrulline is contributing the sixth ligand to heme iron, probably through the thioureido sulfur. Such interaction with heme iron neither stimulates nor inhibits the direct flavin-mediated cytochrome c reduction activity of the enzyme, but it does inhibit heme-dependent superoxide formation. In vivo, L-thiocitrulline is a potent pressor agent in both normal and endotoxemic rats, the latter finding suggesting utility in treating the hypotension of septic shock. 相似文献
69.
After being poisoned by eating the mushroom species Cortinarius speciosissimus, a twin developed interstitial nephritis with acute renal failure. He received a renal transplant from his living twin brother, who was presumed dizygotic on phenotypic grounds. Fifteen years later, the twins were zygosity tested by DNA "fingerprint analysis" and found to be monozygotic, despite important phenotypic discordances. The recipient has discontinued immunosuppression therapy and remains well after 9 months. We suggest that, for medical and other reasons, zygosity should be determined at birth on all like-sexed twins. 相似文献
70.
SS Cohen DJ Mason LS Arsenie SM Sargese D Needham 《Canadian Metallurgical Quarterly》1998,23(6):48, 54, 57-460 passim
Decades of practice and research suggest that nurse practitioners (NPs) provide cost-effective and high-quality care. Managed care's emphasis on prevention and cost savings led some policy makers to view NPs as a way to meet the need for primary care providers. However, access to and utilization of NPs has increasingly been controlled by managed care organizations (MCOs) through their selection of providers for primary care panels. This study employed qualitative methodology to examine NPs' experiences with MCOs. Three focus groups, comprising 27 NPs in New York and Connecticut, revealed NPs' mixed reactions to managed care and a range of sentiments regarding NPs' efforts to be listed as primary care providers. The results reflected NPs' concerns about their perceived "invisibility," as well as their sense of "invincibility" in the ways in which NPs are responding to the barriers posed by MCOs. They identified barriers to, as well as ways to facilitate, being listed by MCOs, and described the importance of NPs working individually and collectively in negotiating with MCOs. 相似文献