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Donner-Banzhoff N, Chan Y, Szalai JP, Hilditch JR. Low blood pressure associated with low mood: a red herring? J Clin Epidemiol 1997; 50:1175-81. [PMID: 9368526 DOI: 10.1016/s0895-4356(97)00157-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE Several reports have discussed a relationship between blood pressure (BP) and psychological well-being scales. Lower BP readings were associated with higher levels of psychological distress and fatigue. This study sought to replicate the association found by previous secondary analyses of epidemiological surveys. DESIGN Cross-sectional study. SETTING Academic Family Medicine Department in Toronto, Canada. SUBJECTS 214 practice attenders. STUDY MEASURES: Extent of psychological abnormalities with the General Health Questionnaire (GHQ), self-reported fatigue, in-clinic and home BP measurements. RESULTS No significant relationship between blood pressure levels and GHQ-score or fatigue could be demonstrated. This applies to clinic and home measurements for systolic and diastolic pressure. Neither adjustment for age or sex nor for several confounders through multiple linear regression produced significant associations in the postulated direction. No nonlinear relationship could be shown either. The study had a power of 95% to detect a correlation of r = 0.22 (alpha = 0.05, one-sided). CONCLUSION The study specifically addressing the possible link between blood pressure and psychological dysfunction/fatigue, could not confirm the previously reported association. Problems related to type-I error in epidemiological research are discussed.
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Poon WS, Chan Y, Kay RL. Phenytoin or sodium valproate for prophylaxis of postoperative convulsions: A randomised comparison. Clin Neurol Neurosurg 1997. [DOI: 10.1016/s0303-8467(97)82166-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
Dystrophin, a component of the muscle membrane cytoskeleton, is the protein altered in Duchenne Muscular Dystrophy (DMD) and Becker Muscular Dystrophy (BMD). Dystrophin shares significant homology with other cytoskeletal proteins, such as alpha-actinin and spectrin. On the basis of its sequence similarity with alpha-actinin and spectrin, dystrophin has been proposed to function as dimer. However, the existence of both dimers and monomers have been observed by electron microscopy. To address this apparent discrepancy, we expressed dystrophin fragments composed of different domains in an in vitro translation system. The expressed fragments were tested for their ability to interact with each other and full-length dystrophin by both immunoprecipitation and blot overlay assays. These assays were successfully used to demonstrate the dimerization of alpha-actinin and spectrin, yet failed to detect any interaction between dystrophin fragments. Although these in vitro results do not prove that dystrophin is not a dimer in vivo, they do indicate that this interaction is not like that of the alpha-actinin and spectrin.
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Chan Y, Chan K, Lam W, Metreweli C. Comparison of whole body MRI and radioisotope bone scintigram for skeletal metastases detection. Chin Med J (Engl) 1997; 110:485-9. [PMID: 9594253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVE To compare whole body magnetic resonance imaging (MRI) using fast sequences with radioisotope bone scintigraphy (BS) for the detection of metastases in the entire skeleton. METHODS AND RESULTS In forty-four patients suffering from carcinoma of lung, breast and prostate whole body MRI could generally be accomplished in about 39 minutes and it was shown to have a higher skeletal metastases detection compared with BS in the spine, pelvis, limb bones, sternum, scapula, and clavicle, but lower in the ribs and skull. CONCLUSIONS We think for addressing the status of skeletal metastases only, bone scintigram is still preferred over whole body MRI. When bone scintigram is unavailable, whole body MRI is a practical and acceptable alternative especially when extra-osseous metastases are also of concern.
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Donner-Banzhoff N, Chan Y, Szalai JP, Hilditch JR. Is the 'clinic-home blood pressure difference' associated with psychological distress? A primary care-based study. J Hypertens 1997; 15:585-90. [PMID: 9218176 DOI: 10.1097/00004872-199715060-00003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE To determine whether there is an association between the 'clinic-home blood pressure difference' (CHBPD) and psychological distress in a sample not selected without regard to blood pressure and hypertension status. DESIGN A cross-sectional study. SETTING An academic family medicine department in Toronto, Canada. PARTICIPANTS Consecutive attenders (n = 214) of the primary care facility. Subjects aged less than 16 years and those being administered psychotropic or blood pressure-lowering agents were excluded. MAIN OUTCOME MEASURES The CHBPD was calculated from clinic blood pressure readings and self-measurements by subjects at home; psychological distress was measured by the 30-item version of the General Health Questionnaire (GHQ). RESULTS No significant association between the CHBPD and psychological distress could be shown for systolic and diastolic blood pressures. The same applied to GHQ subdomains and the CHBPD modelled on several independent variables by multiple linear regression analyses. CONCLUSION The results from this study, using a large sample drawn from a community, support the view that the CHBPD is not related to anxiety, depression and other forms of psychological distress, but rather is a reaction specific to the clinic setting itself.
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Mathi SK, Chan Y, Li X, Wheeler MB. Scanning of the glucagon-like peptide-1 receptor localizes G protein-activating determinants primarily to the N terminus of the third intracellular loop. Mol Endocrinol 1997; 11:424-32. [PMID: 9092794 DOI: 10.1210/mend.11.4.9913] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
It is well known that glucagon-like peptide-1 (7-36 amide) (tGLP-1) is a potent insulinotropic hormone with powerful antidiabetogenic effects. In the present study we sought to determine the precise regions of the intracellular domains of the tGLP-1 receptor that are required for its efficient coupling to adenylyl cyclase because cAMP is the primary candidate second messenger coupling tGLP-1 to insulin secretion. Recently, we identified an amino acid within the third intracellular loop, K334, that was required for efficient coupling of tGLP-1 receptor to adenylyl cyclase. A similar mutagenesis-based strategy was employed here to examine the first and second intracellular loops and to further define sequences in the third loop required for the efficient coupling of the receptor to its second messengers. Receptor mutants were expressed in COS-7 cells and examined for tGLP-1 binding and cAMP stimulation. Three alanine substitution mutations, V327A, 1328A, and V331A, resulted in significantly lower tGLP-1-stimulated cAMP production without reductions in receptor expression. Analysis of the first and second intracellular loops revealed only one mutation contained within the first loop, R176A, where a significant reduction in cAMP activation was observed with normal receptor expression. These studies suggest that specific determinants of coupling for tGLP-1 receptor are primarily localized to the predicted junction of the fifth transmembrane helix and the third intracellular loop. We predict that V327, 1328, and V331 form part of a hydrophobic face that directly contacts the G protein.
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132
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Wong SM, Mahtani PH, Lee KC, Yu HH, Tan Y, Neo KK, Chan Y, Wu M, Chng CG. Cymbidium mosaic potexvirus RNA: complete nucleotide sequence and phylogenetic analysis. Arch Virol 1997; 142:383-91. [PMID: 9125051 DOI: 10.1007/s007050050084] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The complete nucleotide sequence of the genomic RNA of cymbidium mosaic potexvirus (CymMV) was determined to be 6227 nucleotides in length, excluding the poly (A) tail at the 3' terminus. Similar to other potexviruses, its genome organisation is comprised of five major open reading frames (ORFs 1 to 5), encoding a Mr 160 KDa putative RNA-dependent RNA polymerase (RdRp); a Mr 26KDa/13KDa/10KDa triple-gene-block (TGB) and a Mr 24 KDa coat protein. The CymMV encoded proteins shared a high degree of homology to their corresponding proteins of other members of the potexvirus group. The nucleotide sequence of the 5' noncoding region (NCR) of CymMV and all other potexviruses initiates with GAAAA. CymMV possesses the shortest 5' NCR among all potexviruses. Based on phylogenetic comparisons of RdRp and coat protein, CymMV shares a close relationship to PAMV, NMV, WClMV and SMYEaV. This is believed to be the first record of the complete nucleotide sequence of CymMV.
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Chan Y, Wapner R, Kauffman M, Weinblatt V, Jackson L. Outcomes and complications of second and third trimester placental biopsy. Am J Obstet Gynecol 1997. [DOI: 10.1016/s0002-9378(97)80094-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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134
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Scarpaci JA, Chan Y, DiGregorio D, Harmon BA, Pouliot J, Stokstad RG, Suro J. Central collisions in the 16O+12C reaction at 32.5 MeV/nucleon. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1995; 52:764-774. [PMID: 9970568 DOI: 10.1103/physrevc.52.764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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135
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Murgatroyd JT, Bennett SJ, Fulton BR, Pople JS, Jarvis NS, Watson DL, Rae WD, Chan Y, DiGregorio D, Scarpaci J, Stokstad RG. Evidence for 16O+12C cluster structure in 28Si. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1995; 51:2230-2232. [PMID: 9970295 DOI: 10.1103/physrevc.51.2230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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136
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Chan Y, Anton-Lamprecht I, Yu QC, Jäckel A, Zabel B, Ernst JP, Fuchs E. A human keratin 14 "knockout": the absence of K14 leads to severe epidermolysis bullosa simplex and a function for an intermediate filament protein. Genes Dev 1994; 8:2574-87. [PMID: 7525408 DOI: 10.1101/gad.8.21.2574] [Citation(s) in RCA: 162] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Since their discovery, the function of intermediate filaments (IFs) has remained obscure. In skin, epidermal cells have extensive cytoskeletal architectures of IFs, composed of type I and type II keratin heterodimers. Clues to possible functions of these proteins have come from recent studies showing that several autosomal-dominant, blistering skin disorders are caused by defects in genes that encode epidermal keratins. These diseases all exhibit cell degeneration and keratin network perturbations in cells that express the particular mutant keratin gene. However, it is not clear from these studies whether cytolysis arises from the presence of large insoluble keratin aggregates that compromise cellular physiology or from the absence of an extensive keratin filament network, which jeopardizes mechanical integrity. We report here the analysis of an extremely rare case of severe recessive epidermolysis bullosa simplex (EBS), where the patient lacks a discernible keratin filament network in basal epidermal cells. Genetic analyses revealed a homozygous point mutation that yielded a premature termination codon in the major basal type I keratin gene and caused complete ablation of K14. The consanguineous parents were normal, each harboring one copy of the null K14 mutation. Analysis of cultured keratinocytes enabled us to document that the loss of K14 is not compensated for by the up-regulation of any other type I keratin. When taken together with the in vivo studies showing the presence of cell fragility generated from the lack of an extensive basal keratin network, these findings provide the first clear demonstration of loss of function associated with the absence of an IF protein in vivo.
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Chan Y, Chien R. Identification and analyses of periodontal pathogens in Taiwan by microbiological tests. ZHONGHUA MINGUO WEI SHENG WU JI MIAN YI XUE ZA ZHI = CHINESE JOURNAL OF MICROBIOLOGY AND IMMUNOLOGY 1994; 27:59-69. [PMID: 9747334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The purpose of this study was to use microbiological tests for diagnosis of periodontal diseases in Taiwan. Anaerobic culture, direct microscopy, indirect immunofluorescence (IF), and biochemical tests were used to examine 336 samples for the specific microorganisms in subgingival plaque. The results indicated that gram-negative species and motile bacteria were less frequently detected, and in lower proportion, in samples from healthy sites. The bacteria found frequently in healthy group were the coccal forms. However, Bacteroides forsythus detected by IF showed a close association with periodontal inflammation. Porphyromonas gingivalis was found with about 53% frequency in the periodontitis group; in more than half the samples the proportion was above 5%. Actinobacillus actinomycetemcomitans was recovered with 48% frequency of periodontitis group. Other cultivable species including Campylobacter rectus, Capnocytophaga species, Centipeda periodontii, Eikenella corrodens, Fusobacterium nucleatum, Prevotella intermedia, Selenomonas species, and the Spirochetes were detected in a significantly higher proportion in periodontitis group. The results strongly support the use of microbiological tests as adjuncts to diagnosis, and for assessment of the importance of microbiota in periodontal disease.
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Bardayan DW, Chan Y, García A, Hindi MM, Larimer R, Lesko KT, Norman EB, Rossi DF, Stokstad RG, Wietfeldt FE, Zlimen I. Thick-target yields of iodine isotopes from proton interactions in Te, and the double- beta decays of 128,130Te. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1993; 48:3106-3109. [PMID: 9969185 DOI: 10.1103/physrevc.48.3106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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139
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Chan Y, García A, Hindi MM, Kenchian G, Larimer R, Lesko KT, Norman EB, Stokstad RG, Wietfeldt FE, Zlimen I. Search for the beta + decay of 54Mn. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1993; 48:3110-3112. [PMID: 9969186 DOI: 10.1103/physrevc.48.3110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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140
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Chavez-Lomeli E, Dacal A, Ortiz ME, Gazes SB, Chan Y, Stokstad RG, Plagnol E, Siwek-Wilczynska K, Wilczynski J. 16O breakup in quasielastic reactions near the Fermi energy. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1993; 48:699-710. [PMID: 9968881 DOI: 10.1103/physrevc.48.699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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141
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Webb DR, Redgrave N, Chan Y, Harewood LM. Extraperitoneal laparoscopy: early experience and evaluation. THE AUSTRALIAN AND NEW ZEALAND JOURNAL OF SURGERY 1993; 63:554-7. [PMID: 8317982 DOI: 10.1111/j.1445-2197.1993.tb00451.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
This paper evaluates the use of various balloon dilators in the flank, iliac fossa and retro-pubic regions to create extraperitoneal spaces for subsequent extraperitoneal laparoscopy. Eight patients were investigated, three undergoing pelvic surgery, four renal surgery (two nephrectomies) and one laparoscopic ureterolithotomy. Extraperitoneal balloon dilatation was simple, safe and easy and provided large tamponaded bloodless cavities and excellent vision. Port access was slightly restricted by the lateral peritoneal reflections and bony prominences of the thorax and pelvis. This approach for laparoscopy is safe, simple and deserving of further evaluation.
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Hanash SM, Strahler JR, Chan Y, Kuick R, Teichroew D, Neel JV, Hailat N, Keim DR, Gratiot-Deans J, Ungar D. Data base analysis of protein expression patterns during T-cell ontogeny and activation. Proc Natl Acad Sci U S A 1993; 90:3314-8. [PMID: 8475073 PMCID: PMC46290 DOI: 10.1073/pnas.90.8.3314] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
We have developed a data base of lymphoid proteins detectable by two-dimensional polyacrylamide gel electrophoresis. The data base contains two-dimensional patterns and derived information pertaining to polypeptide constituents of unstimulated and stimulated mature T cells and immature thymocytes, single-cell-derived T- and B-cell clones, leukemia cells, and lymphoid cell lines. Using this data base, we have compared the protein constituents of mature T cells and immature thymocytes before and after mitotic stimulation. A subset of polypeptides that are induced in mature T cells following mitotic stimulation were found to be constitutively expressed in immature thymocytes. Other polypeptides exhibited differences in their expression between mature and immature thymocytes in a manner unrelated to proliferation. The identity of several constitutively expressed or mitotically induced proteins in lymphoid cells was established by microsequencing. These initial findings point to significant differences in the molecular pathways leading to proliferation between mature and immature T cells. The construction of this database should facilitate further studies of lymphoid differentiation and function.
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143
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Webb DR, Redgrave N, Chan Y. Retropubic extraperitoneal endoscopy. Med J Aust 1992; 157:843. [PMID: 1454032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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144
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Chan Y, Larimer R, Lesko KT, Norman EB, Stokstad RG, Wietfeldt FE, Zlimen I. Half-life of 56Ni. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1992; 46:1132-1135. [PMID: 9968218 DOI: 10.1103/physrevc.46.1132] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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145
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Zlimen I, Browne E, Chan Y, García A, Larimer R, Lesko KT, Norman EB, Stokstad RG, Wietfeldt FE. Second-forbidden electron-capture decay of 55Fe. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1992; 46:1136-1138. [PMID: 9968219 DOI: 10.1103/physrevc.46.1136] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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146
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Pacheco AJ, DiGregorio DE, Testoni JE, Chan Y, Chávez E, Gazes S, Plagnol E, Stokstad RG. Capture reactions in the 40,48Ca+197Au and 40,48Ca+208Pb systems. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1992; 45:2861-2869. [PMID: 9968051 DOI: 10.1103/physrevc.45.2861] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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147
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Ali I, Chan Y, Kuick R, Teichroew D, Hanash SM. Implementation of a two-dimensional electrophoresis-related laboratory information processing system: database aspects. Electrophoresis 1991; 12:747-61. [PMID: 1802692 DOI: 10.1002/elps.1150121008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A laboratory information processing system (LIPS) has been developed to provide support for various laboratory activities related to two-dimensional electrophoresis. In this paper we present the relational schema for each level of activity and the application development of LIPS, in terms of the relational database management system being used. We also discuss our experience with the current system.
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148
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DiGregorio DE, Chan Y, Chavez E, Dacal A, Ortiz ME, Suro J, Stokstad RG. Fusion cross sections for 12C+128Te and the deduction of absolute average angular momenta. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1991; 43:687-690. [PMID: 9967109 DOI: 10.1103/physrevc.43.687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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149
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Pouliot J, Chan Y, DiGregorio DE, Harmon BA, Knop R, Moisan C, Roy R, Stokstad RG. Excitation and multiple dissociation of 12C, 14N, and 16O projectiles in peripheral collisions at 32.5 MeV/nucleon. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1991; 43:735-744. [PMID: 9967114 DOI: 10.1103/physrevc.43.735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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150
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DiGregorio DE, Lesko KT, Harmon BA, Norman EB, Pouliot J, Sur B, Chan Y, Stokstad RG. Angular momentum in sub-barrier fusion: Experimental study using the isomer ratio 137Cem/137Ceg. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1990; 42:2108-2124. [PMID: 9966959 DOI: 10.1103/physrevc.42.2108] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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