Study of a mechanism responsible for anomalous results for free thyroxin by some analog assays for subjects with albumin deficiency.

1984 ◽  
Vol 30 (11) ◽  
pp. 1742-1745 ◽  
Author(s):  
T J Wilke

Abstract I examined the effect of albumin deficiency, as might occur in pregnancy and nonthyroidal illness, on four analog-based assays for free thyroxin (Amersham's Amerlex, Diagnostic Products Corporation's Coat-A-Count "one-step," Clinical Assays' Gammacoat "one-step," and Corning's Immophase "single-step"). In subjects with albumin deficiency per se, Amerlex and Coat-A-Count results for free thyroxin were not significantly different from normal, whereas free thyroxin values by Gammacoat and Immophase assays were lower than that of the control. Furthermore, in the albumin-deficient group, the mean amount of thyroxin associated with antisera in each assay was significantly higher than that of the control and correlated well with the degree of decrease in free thyroxin. I conclude that subnormal results for thyroxin by analog assays, in euthyroid patients with albumin deficiency, is a function of the specific assays and is not a characteristic of analog assays per se. In addition, the study suggests that albumin deficiency alters the distribution between thyroxin and its binders in all four analog assays, but only in the Gammacoat and Immophase methods is this alteration sufficiently large as to distort assay results.

2011 ◽  
Vol 24 (2) ◽  
pp. 01-08
Author(s):  
B. Kumar ◽  
N. K. Patra

Opium poppy (Papaver somniferum L.) is an important medicinal plant produces more than 80 alkaloids obtained from the capsules and straw of the plant. The estimate of combining ability gives an indication of the genetic behaviour of the parental material. It is therefore, desirable to select the parents for hybridization on the basis of their per se performance and combining ability effects. The F1, F2 and their reciprocals of an eight parent diallel cross in opium poppy were studied for combining ability of seven economic traits. The mean sum of squares due to GCA, SCA and reciprocals were significant for all the traits. The magnitude of GCA variances were invariably higher than those of SCA and thus indicating the preponderance of non-additive genetic variances, which was further affirmed by the measure of average degree of dominance i.e. ?(?2s/? 2g).  Among the parents VN35I for plant height, Sanchita and VG26 for capsules per plant, VN23, VN35I and Vivek for capsule index, VG26 and Sanchita for seed and straw yield per plant, and VN35I and VG20 for morphine content were found good general combiners. Earliness being a desired trait, parent VG20 having significant negative GCA estimates coupled with per se performance can be considered as good general combiner for early flowering. Inclusion of good general combiners in a multiple crossing program or an inter-mating population involving all possible crosses among them subjected to bi-parental mating may be expected to offer maximum promise in breeding for economic traits.DOI: http://dx.doi.org/10.3329/bjpbg.v24i2.17000


1972 ◽  
Vol 71 (1) ◽  
pp. 24-36 ◽  
Author(s):  
Ariel Gordin ◽  
Pirkko Saarinen

ABSTRACT An account is given of a methodological study of the double-antibody radioimmunoassay of human TSH, using highly purified labelled human TSH as tracer. It was shown that conventional paper electrophoresis was not adequate for studying the purity of labelled human TSH. When polyvinylchloride (Pevikon®) electrophoresis was used, four subfractions could still be separated, even though, on paper electrophoresis, the material seemed to be homogeneous. Only two of the four Pevikon fractions were immunoreactive. Purification of labelled human TSH by Pevikon electrophoresis also improved the sensitivity of the assay. Specific activities of about 100 mCi/mg gave the highest initial binding capacity, produced least damage to the labelled hormone and showed the best stability of the tracer without influencing the sensitivity of the method. In different storage conditions, labelled human TSH was found to be most stable at −20°C and diluted 1/100. Only in pregnancy did the addition of HCG seem necessary. The mean TSH value in healthy subjects was 3.6 ± 1.4 μU/ml (mean±sd) with a range from 1.6 μU/ml to 8.8 μU/ml.


Synthesis ◽  
2021 ◽  
Author(s):  
Sambasivarao Kotha ◽  
Sunil Pulletikurti ◽  
Ambareen Fatma ◽  
gopal dhangar ◽  
gonna somu Naidu

Here, we have demonstrated that the presence of a carbonyl group at C7 position is preventing the olefin metathesis of endo-norbornene derivatives due to the complexation of the metal alkylidene. Time-dependent NMR studies showed the presence of new proton signals in the metal alkylidene region, which indicate the formation of metal complex with the carbonyl group of the substrate. These observations were further proved by ESI-MS analysis. Whereas, computational studies provided that the catalyst was interacting with the C7 carbonyl group and aligned perpendicular to that of norbornene olefin. Later, these endo-keto norbornene derivatives were reduced to hydroxyl derivatives diastereoselectively. Ring-rearrangement metathesis (RRM) of these hydroxyl derivatives, produced the [6/5/6], and [5/6/5] carbo-tricyclic cores of the natural products in one step. Whereas the RRM of O-allyl derivatives, delivered the oxa-tricyclic compounds in a single step with excellent yields.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Afsaneh Keramat ◽  
Mina Malary ◽  
Mahmood Moosazadeh ◽  
Nastaran Bagherian ◽  
Mohammad-Reza Rajabi-Shakib

Abstract Background Pregnancy is a unique period with the increased likelihood of psychological changes and emotional disturbances such as depression, anxiety, and stress. In this study, we investigated the factors influencing depression, anxiety, and stress in pregnancy and identify their associations with Sexual Distress (SD) and Genital Self-Image (GSI). Methods This was a descriptive, correlational, cross-sectional study performed using the two-stage cluster sampling method between September 2019 and January 2020. Overall, 295 pregnant women completed a demographics and obstetric information checklist, Depression Anxiety and Stress Scale-21 (DASS-21), Female Genital Self-Image Scale (FGSI), and Female Sexual Distress Scale-Revised (FSDS-R). Results Analysis of Variance (ANOVA) showed significant differences in the mean scores of SD between the groups with varying degrees of depression, anxiety, and stress (P <  0.001) and in the mean score of GSI between the groups with varying degrees of depression (P = 0.01) and anxiety (P <  0.001). In multivariate linear regression analysis, higher (worse) depression, anxiety, and stress scores were found in women with more advanced age and higher SD scores; however, these scores were lower (better) in those with increased gestational age. Lower depression and anxiety scores were associated with moderate satisfaction with income, moderate satisfaction with BI in pregnancy, and lower stress and depression scores were linked to planned pregnancy. Higher (better) GSI score was a predictor of lower depression score, complication in a previous pregnancy was a predictor of higher stress score, and finally, fear of fetal abortion and being a housewife were predictors of a higher anxiety score. Conclusion Various factors contribute to the development of antenatal depression, anxiety, and stress. A positive correlation was found between SD and the severity of depression, anxiety, and stress, while a negative correlation was noted between GSI and the severity of depression and anxiety. Therefore, raising awareness regarding SD and GSI through screening and counseling sessions can have beneficial effects for mothers and their fetuses.


Electronics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1275
Author(s):  
Simone Scafati ◽  
Enza Pellegrino ◽  
Francesco de Paulis ◽  
Carlo Olivieri ◽  
James Drewniak ◽  
...  

The de-embedding of measurement fixtures is relevant for an accurate experimental characterization of radio frequency and digital electronic devices. The standard technique consists in removing the effects of the measurement fixtures by the calculation of the transfer scattering parameters (T-parameters) from the available measured (or simulated) global scattering parameters (S-parameters). The standard de-embedding is achieved by a multiple steps process, involving the S-to-T and subsequent T-to-S parameter conversion. In a typical measurement setup, two fixtures are usually placed before and after the device under test (DUT) allowing the connection of the device to the calibrated vector network analyzer coaxial ports. An alternative method is proposed in this paper: it is based on the newly developed multi-network cascading algorithm. The matrices involved in the fixture-DUT-fixture cascading gives rise to a non-linear set of equations that is in one step analytically solved in closed form, obtaining a unique solution. The method is shown to be effective and at least as accurate as the standard multi-step de-embedding one.


2002 ◽  
Vol 11 (1) ◽  
pp. 42-49
Author(s):  
Devin L. McCaslin ◽  
Lawrence L. Feth ◽  
Gary P. Jacobson ◽  
Pamela J. Mishler

This investigation was conducted to determine whether an exogenous event-related potential called the mismatch negativity (MMN) would change systematically in response to frequency-modulated signals with varying temporal properties. Both N1 and P2 waveforms were recorded for 50-ms frequency-modulated signals from normal hearing listeners. The standard stimuli for this investigation were continuous sweep tones with center frequencies of 1000 Hz that traversed a frequency range of 200 Hz in a single step. The rare stimuli were signals that traversed the same frequency range in two, four, six, or eight discrete steps. Results suggest that for the 10 participants, 1) the mean MMN peak-to-peak amplitude and mean area decreased significantly with decreases in step duration, 2) MMN area amplitude was the best indicator of psychophysical performance for the two magnitude measures, and 3) MMN onsets and peak latencies did not show either a significant increase or decrease in latency as step duration decreased.


1969 ◽  
Vol 60 (4) ◽  
pp. 579-585
Author(s):  
K. Schollberg ◽  
E. Seiler ◽  
J. Holtorff

ABSTRACT The urinary excretion of testosterone and epitestosterone by women in late pregnancy has been studied. The mean values of 22 normal women in pregnancy mens X are 12.9 ± 9.2 μg/24 h in the case of testosterone and 16.1 ± 16.2 μg/24 h in the case of epitestosterone. Both values do not differ significantly from those of non-pregnant females. The excretion values of mothers bearing a male foetus (17.3 ± 8.9 μg/24 h) are higher than those of mothers with a female foetus (6.4 ± 4.8 μg/24 h). The difference is statistically significant with P = 0.01.


2016 ◽  
Vol 113 (28) ◽  
pp. 7722-7726 ◽  
Author(s):  
Gavin O. Jones ◽  
Alexander Yuen ◽  
Rudy J. Wojtecki ◽  
James L. Hedrick ◽  
Jeannette M. García

It is estimated that ∼2.7 million tons poly(carbonate)s (PCs) are produced annually worldwide. In 2008, retailers pulled products from store shelves after reports of bisphenol A (BPA) leaching from baby bottles, reusable drink bottles, and other retail products. Since PCs are not typically recycled, a need for the repurposing of the PC waste has arisen. We report the one-step synthesis of poly(aryl ether sulfone)s (PSUs) from the depolymerization of PCs and in situ polycondensation with bis(aryl fluorides) in the presence of carbonate salts. PSUs are high-performance engineering thermoplastics that are commonly used for reverse osmosis and water purification membranes, medical equipment, as well as high temperature applications. PSUs generated through this cascade approach were isolated in high purity and yield with the expected thermal properties and represent a procedure for direct conversion of one class of polymer to another in a single step. Computational investigations performed with density functional theory predict that the carbonate salt plays two important catalytic roles in this reaction: it decomposes the PCs by nucleophilic attack, and in the subsequent polyether formation process, it promotes the reaction of phenolate dimers formed in situ with the aryl fluorides present. We envision repurposing poly(BPA carbonate) for the production of value-added polymers.


2014 ◽  
Vol 745 ◽  
pp. 647-681 ◽  
Author(s):  
Yee Chee See ◽  
Matthias Ihme

AbstractLocal linear stability analysis has been shown to provide valuable information about the response of jet diffusion flames to flow-field perturbations. However, this analysis commonly relies on several modelling assumptions about the mean flow prescription, the thermo-viscous-diffusive transport properties, and the complexity and representation of the chemical reaction mechanisms. In this work, the effects of these modelling assumptions on the stability behaviour of a jet diffusion flame are systematically investigated. A flamelet formulation is combined with linear stability theory to fully account for the effects of complex transport properties and the detailed reaction chemistry on the perturbation dynamics. The model is applied to a methane–air jet diffusion flame that was experimentally investigated by Füriet al.(Proc. Combust. Inst., vol. 29, 2002, pp. 1653–1661). Detailed simulations are performed to obtain mean flow quantities, about which the stability analysis is performed. Simulation results show that the growth rate of the inviscid instability mode is insensitive to the representation of the transport properties at low frequencies, and exhibits a stronger dependence on the mean flow representation. The effects of the complexity of the reaction chemistry on the stability behaviour are investigated in the context of an adiabatic jet flame configuration. Comparisons with a detailed chemical-kinetics model show that the use of a one-step chemistry representation in combination with a simplified viscous-diffusive transport model can affect the mean flow representation and heat release location, thereby modifying the instability behaviour. This is attributed to the shift in the flame structure predicted by the one-step chemistry model, and is further exacerbated by the representation of the transport properties. A pinch-point analysis is performed to investigate the stability behaviour; it is shown that the shear-layer instability is convectively unstable, while the outer buoyancy-driven instability mode transitions from absolutely to convectively unstable in the nozzle near field, and this transition point is dependent on the Froude number.


Nutrients ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 916 ◽  
Author(s):  
Andrea Hemmingway ◽  
Karen O’Callaghan ◽  
Áine Hennessy ◽  
George Hull ◽  
Kevin Cashman ◽  
...  

Adverse effects of low vitamin D status and calcium intakes in pregnancy may be mediated through functional effects on the calcium metabolic system. Little explored in pregnancy, we aimed to examine the relative importance of serum 25-hydroxyvitamin D (25(OH)D) and calcium intake on parathyroid hormone (PTH) concentrations in healthy white-skinned pregnant women. This cross-sectional analysis included 142 participants (14 ± 2 weeks’ gestation) at baseline of a vitamin D intervention trial at 51.9 °N. Serum 25(OH)D, PTH, and albumin-corrected calcium were quantified biochemically. Total vitamin D and calcium intakes (diet and supplements) were estimated using a validated food frequency questionnaire. The mean ± SD vitamin D intake was 10.7 ± 5.2 μg/day. With a mean ± SD serum 25(OH)D of 54.9 ± 22.6 nmol/L, 44% of women were <50 nmol/L and 13% <30 nmol/L. Calcium intakes (mean ± SD) were 1182 ± 488 mg/day and 23% of participants consumed <800 mg/day. The mean ± SD serum albumin-adjusted calcium was 2.2 ± 0.1 mmol/L and geometric mean (95% CI) PTH was 9.2 (8.4, 10.2) pg/mL. PTH was inversely correlated with serum 25(OH)D (r = −0.311, p < 0.001), but not with calcium intake or serum calcium (r = −0.087 and 0.057, respectively, both p > 0.05). Analysis of variance showed that while serum 25(OH)D (dichotomised at 50 nmol/L) had a significant effect on PTH (p = 0.025), calcium intake (<800, 800–1000, ≥1000 mg/day) had no effect (p = 0.822). There was no 25(OH)D-calcium intake interaction effect on PTH (p = 0.941). In this group of white-skinned women with largely sufficient calcium intakes, serum 25(OH)D was important for maintaining normal PTH concentration.


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