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51.
From high-resolution infrared spectra of 14N12C12C14N, 14N13C13C14N, and 15N12C12C15N, we find that the levels 1000(0)0(0), 1000(0)1(1), 1000(0)2(0,2), and 1000(0)3(1,3) have very pronounced perturbations. Our analysis shows that these perturbations are due to a vibrational resonance among the levels 1000(0)0(0), 0102(0)2(0), and 0102(0)2(2) in the one case, and equivalent levels with one or more additional quanta of nu5 in the other three cases. The resonance constant for the perturbation involving nu1 is 0.25 cm-1. It has the dependence on v5 and l5 that is expected for the sextic potential constant, K124455, although it seems too large for such a high-order constant. The Deltal (or Deltak) = 2 interaction between, for instance, 1000(0)0(0) and 0102(0)2(2e) is shown to be primarily due to the l-type resonance mixing of the 0102(0)2(0) and 0102(0)2(2e) states. The resonance is nearly "turned off" for the 1000(0)2(0,2) and 1000(0)3(1,3) states of 14N13C13C14N because there are no level crossings between the interacting states and the band centers are too far away to have an obvious effect, although careful analysis shows that the perturbation can be seen in their effective centrifugal distortion constants. The spectrum of 15N12C12C15N shows level crossings only in the case of the 1000(0)1(1), 1000(0)2(0,2), and 1000(0)3(1,3) states. Copyright 1999 Academic Press. 相似文献
52.
Even simple and relatively safe provocation procedures like nasal allergen challenges, should aim to allow detection of positivity with the less possible discomfort to the patient. The objective of this work was to evaluate if the use of rhinomanometric measurements during nasal provocation procedures could allow a decrease in the total administered allergen dose, causing less symptoms to the patients but without increasing the number of false-negatives, comparatively to clinical scores or nasal peak-flow measurements. Our results showed that performing rhinomanometric measurements during nasal HDM challenge procedures can lead in many patients to a reduction in the total dose of allergen administered during the challenge, without loss of sensitivity or specificity. This allergen dose reduction translates in less time consumed during the provocation and less patients' discomfort. 相似文献
53.
AV Demin AV Kolesnikov MA Olfer'ev PV Favorov KV Fegeding AG Gabibov NV Gnuchev 《Canadian Metallurgical Quarterly》1998,34(10):1333-1337
A new system for the expression of a catalytic light chain antibody to the vasoactive intestinal peptide is described. The system made possible the isolation the large amounts of a homogeneous protein without any additional peptide domains. The preparation obtained can be used in further experiments on light chain crystallization and in X-ray-structural analysis of its catalytic center. 相似文献
54.
JG De Man GE Boeckxstaens BY De Winter TG Moreels ME Misset AG Herman PA Pelckmans 《Canadian Metallurgical Quarterly》1995,114(6):1179-1184
1. In organ bath experiments, hydroquinone (30-100 microM) and hydroxocobalamin (30-100 microM) concentration-dependently inhibited the relaxations induced by NO (0.3-30 microM) but not those by nitroglycerin (GTN, 1 microM) in the canine ileocolonic junction (ICJ). Hydroxocobalamin reduced the relaxation to low frequency (2 Hz) stimulation of the non-adrenergic, non-cholinergic (NANC) nerves, whereas hydroquinone only reduced the NANC nerve-mediated relaxations to electrical stimulation at 16 Hz, 0.5 ms. 2. Relaxations to S-nitroso-L-cysteine (CysNO, 1-30 microM), or S-nitroso-N-acetyl-D,L-penicillamine (SNAP, 1-30 microM) were not inhibited by hydroquinone (30-100 microM), hydroxocobalamin (30-100 microM), pyrogallol (30-100 microM) or L-cysteine (1-3 microM). Hydroquinone (100 microM) only reduced the relaxation to 10 microM CysNO. Hydroxocobalamin, but not hydroquinone, pyrogallol or L-cysteine, potentiated the relaxations to the lowest concentration (1 microM) of S-nitrosoglutathione (GSNO, 1-30 microM). 3. In the superfusion bioassay, hydroquinone (100 microM) and hydroxocobalamin (1 microM) concentration-dependently inhibited the biological activity of authentic NO (1-4 pmol) to the same extent as that of the transferable nitrergic factor, released from the canine ICJ in response to NANC nerve stimulation (8-16 Hz, 2 ms). Responses to GTN (10 pmol) or adenosine 5'-triphosphate (10 nmol) were not affected. 4. In conclusion, the nitrosothiols CysNO, SNAP and GSNO relax the canine ileocolonic junction, but these relaxations, pharmacologically, behave differently from the NANC nerve-mediated relaxations. From the bioassay experiments, we conclude that the nitrergic factor, released in response to NANCnerve stimulation of the canine ICJ, behaves pharmacologically like NO but not like a nitrosothiol.Therefore, we suggest NO, and not CysNO, SNAP or GSNO as the inhibitory NANC neurotransmitter in the canine ICJ. 相似文献
55.
AG Baxter F Hamilton TE Mandel C Augustine A Cooke G Morahan 《Canadian Metallurgical Quarterly》1993,20(5):409-417
The basis for diabetes resistance in low diabetes incidence NOD/Wehi mice was examined in a breeding study. NOD/Wehi mice were crossed with high diabetes incidence NOD/Lt mice producing F1 hybrid mice which expressed a low incidence of diabetes. To distinguish between genetic and environmental causes for diabetes resistance, these F1 mice were backcrossed to NOD/Lt mice resulting in BC1 hybrid mice which expressed an intermediate incidence of diabetes. Similar results were obtained by examining the severity of insulitis in the hybrid mice. As both the incidence of diabetes and severity of insulitis in the hybrid mice were consistent with a single dominant gene mediating diabetes resistance, an attempt to localize this gene was made. Although over 140 loci which display polymorphism amongst inbred strains were typed in both parental lines, only a single locus, D8Mit9, was found to differ. As heterozygotes at D8Mit9 were not over represented amongst 45 diabetic BC1 hybrid mice examined, it was concluded that a resistance gene was not linked to this locus. 相似文献
56.
BACKGROUND/AIMS: International comparisons of clinical practice may help in assessing the magnitude and possible causes of variation in cross national healthcare utilisation. With this aim, the indications for cataract surgery in the United States, Denmark, the province of Manitoba (Canada), and the city of Barcelona (Spain) were compared. METHODS: In a prospective multicentre study, patients scheduled for first eye cataract surgery and aged 50 years or older were enrolled consecutively. From the United States 766 patients were enrolled; from Denmark 291; from Manitoba 152; and from Barcelona 200. Indication for surgery was measured as preoperative visual status of patients enlisted for cataract surgery. Main variables were preoperative visual acuity in operative eye, the VF-14 score (an index of functional impairment in patients with cataract) and ocular comorbidity. RESULTS: Mean visual acuity were 0.23 (USA), 0.17 (Denmark), 0.15 (Manitoba), and 0.07 (Barcelona) (p < 0.001). When restricting the sample to eyes with normal retina and macula, no significant difference between United States and Denmark was observed (p > 0.05). Mean VF-14 scores were 76 (USA), 76 (Denmark), 71 (Manitoba), and 64 (Barcelona) (p < 0.001). CONCLUSION: Similar indications for cataract surgery were found in the United States and Denmark. Significantly more restricted indications were observed in Manitoba and Barcelona. Possible explanations for the results are discussed, including differences in sociodemographic characteristics, access to care, surgeons' willingness to operate, and patient demand. 相似文献
57.
Based on the study of 66 miners in the subclinical stage of manganotoxicosis the principle functional changes have been ascertained in the given condition. Revealed in the above series were an increased content of manganese in the hair of more than 3 mg% (95.5%-100.0%), the presence of neurosis-like condition presenting with elements of somatized depression, anxiety, asthenization, slight decline in the mnestic functions (69.6%-93.5%), mild impairment of the power of voluntary movement, parasympathetic type vegetative dystonia (42%-73.7%), slight changes in cerebral and peripheral hemodynamics (36.6%-68.6%), disordered bioelectrical activity of muscles of the extrapyramidal type (53.7%-83.2%), breakdown of mechanisms of adaptation of the sympathoadrenal (19.1%-49.3%) and cholinergic (26.3%-57.9%) systems. 相似文献
58.
JM César AG Avello A Vecino C Cerveró JG Lara?a IF Fuertes J Villarrubia J López JP de Oteyza JL Velasco A Cantalapiedra P Herrera S Herrero JL Navarro 《Canadian Metallurgical Quarterly》1998,111(16):601-603
BACKGROUND: To describe the main characteristics and response to desmopressin infusion in 103 patients suffering from von Willebrand disease (vWD). PATIENTS AND METHODS: The criteria for diagnosis were (except for type 2N) the coexistence of von Willebrand factor ristocetin cofactor (vWF:RCo) activity < 50 U/dl with bleeding disease or one of the following data: von Willebrand factor antigen (vWF:Ag) activity < 50 U/dl, factor VIII (FVIII) activity < 50 U/dl or the existence of a increased bleeding time (BT). Multimeric studies of vWF were performed in 51 cases and ristocetin induced platelet aggregation (RIPA) was also performed. RESULTS: Spontaneous bleeding was found in 36 patients, while in 18 cases the diagnosis was done after surgical bleeding. Thirteen patients (6 presenting with mild bleeding) were studied for abnormalities in the routine preanestesic tests. Other 22 patients were diagnosed with vWD by familial studies. There were 3 patients with type 2B, 1 case with type 2N and other patient with type 3. BT was found increased in 26 out of 58 patients. The activities of vWF:CoR and vWF:Ag were 38.4 (9.4) U/dl and 45.8 (23.2) U/dl, respectively, while the activity of FVIII was 49.9 (20.8) U/dl. Prophylactic DDAVP (desmopressin) was infused in 32 patients. After 1 h, basal activities of vWF:CoR and vWF:Ag were increased by 3.1 (3.2) and 3.4 (3.1) times, respectively, and maintained for 3 h. FVIII activity increased 3.6 (2.3) times the basal levels decreasing after 3 h (2.9 [2.1]; p < 0.01). The BT was corrected in 8 out of ten patients. CONCLUSIONS: vWD is a major cause of surgical bleeding. Preanestesic anamnesis and coagulation tests can be useful to identify vWD. Many patients with vWD have normal BT. A failure in the response to desmopressin infusion is unusual. 相似文献
59.
The recent rapid growth of protein sequence databases is outpacing the capacity of researchers to biochemically and structurally characterize new proteins. Accordingly, new methods for recognition of motifs and homologies in protein primary sequences may be useful in determining how these proteins might function. We have applied such a method, an iterative learning algorithm, to analyze possible coiled coil domains in histidine kinase receptors. The potential coiled coils have not yet been structurally characterized in any histidine kinase, and they appear outside previously noted kinase homology regions. The learning algorithm uses a combination of established sequence patterns in known coiled coil proteins and histidine kinase sequence data to learn to recognize efficiently this coiled coil-like motif in the histidine kinases. The common appearance of the structural motif in a functionally important part of the receptors suggests hypotheses for kinase regulation and signal transduction. 相似文献
60.