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1.
Probl Endokrinol (Mosk) ; 65(5): 330-340, 2019 11 23.
Article in Russian | MEDLINE | ID: mdl-32202737

ABSTRACT

BACKGROUND: The most of the current studies include patients who are different by the etiology of secondary adrenal insufficiency (SAI), or investigate SAI among other late effects of the radiation therapy. AIMS: To describe the features of SAI and to select the best method of screening SAI in adult patients followed complex treatment of nonpituitary brain tumors in childhood. MATERIALS AND METHODS: It was the retrospective cross-sectional study. 31 patients after the complex treatment of nonpituitary brain tumors in childhood and 20 healthy volunteers were examined. Age and sex ratio were comparable between the groups. Biochemical and clinical blood tests, levels of cortisol, ACTH, DHEA-C were evaluated. The insulin tolerance test (ITT) was performed for all patients and 11 volunteers. RESULTS: The prevalence of SAI by ITT was 45.2%. The levels of basal cortisol (BC) were significantly higher in patients without SAI in comparison with the SAI group and volunteers (505 [340; 650] vs 323 [233; 382] and 372 [263; 489] nmol / l; pSAI- without_SAI=0.001; pwihtout_SAI-healthy = 0.04). The SAI group had DHEA-C significantly lower than in other groups one (3.1 [1.8; 3.4] vs 5.1 [2.5; 6.4] and 6.8 [4.1; 8.9]; рSAI- without_SAI = 0.036; pSAI-healthy = 0.001). ROC analysis showed that BC and DHEA-S can be used as high-quality screening tests for SAI (AUC = 89.3% and 88.3%). The maximum level of cortisol (656 [608-686] vs 634 [548-677]; p = 1) and the time of its increase (45 and 60 min) did not differ during ITT in patients without SAI and volunteers. Side effects: delayed hypoglycemia occurred in 4/14 patients of the SAI group 4090 minutes late of injection 60-80 ml of 40% glucose solution for stopping hypoglycemia in the test. CONCLUSIONS: 45.2% of patients followed craniospinal irradiation had SAI that is characterized by a decrease in DHEA-C levels. A highly normal level of basal cortisol was observed in 45% of patients without SAI. DHEA-C and blood cortisol can be used for SAI screening.


Subject(s)
Adrenal Insufficiency , Brain Neoplasms , Adrenal Insufficiency/diagnosis , Adrenal Insufficiency/etiology , Brain Neoplasms/complications , Brain Neoplasms/diagnosis , Humans , Hydrocortisone , Retrospective Studies
2.
J Chem Phys ; 139(15): 154203, 2013 Oct 21.
Article in English | MEDLINE | ID: mdl-24160506

ABSTRACT

Perturbation-facilitated two-color resonant four-wave-mixing spectroscopy is realized to access the (dark) triplet manifold of the C3 molecule from the singlet X̃(1)Σg (+) ground state. The inherent nonlinear signal dependence and coherence of the technique result in a favorable detection of the excited triplet states of interest. The observation of a newly found (3)Δu electronic state is achieved by a two-step excitation via "gate-way" levels (i.e., singlet-triplet mixed levels). Additionally, by fixing the probe laser on a transition exhibiting mainly triplet-triplet character and scanning the pump laser, we demonstrate an effective spin-filtering in a four-wave mixing measurement where only transitions to the perturber (3)Σu(-) state appear exclusively in an otherwise congested spectral range of the Comet band. Ab initio calculations of excited triplet states complement our analysis with the electronic assignment of the observed resonances.

3.
J Chem Phys ; 134(4): 044302, 2011 Jan 28.
Article in English | MEDLINE | ID: mdl-21280720

ABSTRACT

In this work we present a deperturbation study of the d (3)Π(g), v=6 state of C(2) by double-resonant four-wave mixing spectroscopy. Accurate line positions of perturbed transitions are unambiguously assigned by intermediate level labeling. In addition, extra lines are accessible by taking advantage of the sensitivity and high dynamic range of the technique. These weak spectral features originate from nearby-lying dark states that gain transition strength through the perturbation process. The deperturbation analysis of the complex spectral region in the (6,5) and (6,4) bands of the Swan system (d(3)Π(g)-a (3)Π(u)) unveils the presence of the energetically lowest high-spin state of C(2) in the vicinity of the d (3)Π(g), v=6 state. The term energy curves of the three spin components of the d state cross the five terms of the 1 (5)Π(g) state at rotational quantum numbers N ≤ 11. The spectral complexity for transitions to the v = 6 level of d (3)Π(g) state is further enhanced by an additional perturbation at N = 19 and 21 owing to the b (3)Σ(g)(-), v=19 state. The spectroscopic characterization of both dark states is accessible by the measurement of 122 "window" levels. A global fit of the positions to a conventional Hamiltonian for a linear diatomic molecule yields accurate molecular constants for the quintet and triplet perturber states for the first time. In addition, parameters for the spin-orbit and L-uncoupling interaction between the electronic levels are determined. The detailed deperturbation study unravels major issues of the so-called high-pressure bands of C(2). The anomalous nonthermal emission initially observed by Fowler in 1910 [Mon. Not. R. Astron. Soc. 70, 484 (1910)] and later observed in numerous experimental environments are rationalized by taking into account "gateway" states, i.e., rotational levels of the d (3)Π(g), v=6 state that exhibit significant (5)Π(g) character through which all population flows from one electronic state to the other.

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