Search PubMed⌕ Search

Biomedical subjects

G Lazarov

Publications and source records attributed to G Lazarov.

At least 19 recordsLinked to original sources
PubMed2001

Enhanced Access to the Dark Triplet States of (7)Li(2) through New Singlet-Triplet A(1)Sigma(+)(u) approximately b(3)Pi(u) Perturbation Window Levels: Perturbation-Facilitated Optical-Optical Double Resonance Study of the 2(3)Sigma(+)(g) State.

Two new pairs of singlet-triplet A(1)Sigma(+)(u) approximately b(3)Pi(u) mixed levels of (7)Li(2) have been observed and used here as "window" levels in cw perturbation-facilitated optical-optical double-resonance (PFOODR) experiments. Previously, only one b(3)Pi(u) vibrational level, v = 19, was known to mix with the singlet A(1)Sigma(+)(u) v = 13 level, resulting in three perturbed A approximately b pairs [L. Li, T. An, T.-J. Whang, A. M. Lyyra, W. C. Stwalley, R. W. Field, and R. A. Bernheim, J. Chem. Phys. 96, 3342 (1992)]. The scarcity of window levels and the resulting difficulty in accessing the dark triplet states of Li(2) is caused by the weak spin-orbit interaction of Li(2). The two new mixed b(3)Pi(u) v = 15 and 22 levels reported here enhance access to the dark triplet state manifold through expansion of the Franck-Condon overlap factor range. Furthermore, the earlier range of accessible rotational levels, N = 5, 7, and 10, is now expanded to include N = 8 and N = 16, thereby allowing for more reliable determination of the excited triplet states rotational structure. To demonstrate the importance of the new A(1)Sigma(+)(u) approximately b(3)Pi(u) mixed levels, we have studied the 2(3)Sigma(+)(g) state by cw PFOODR fluorescence excitation spectroscopy. New molecular constants and RKR potential curve have been determined. As previously reported [L. Li, G. Lazarov, and A. M. Lyyra, J. Mol. Spectrosc. 191, 387 (1998)], the 2(3)Sigma(+)(g) state interacts with the repulsive 1(3)Pi(g) state by L-uncoupling and predissociates. We show that some 2(3)Pi(g) levels predissociate accidentally by the 1(3)Pi(g) state via the 2(3)Sigma(+)(g) state through L-uncoupling. Copyright 2001 Academic Press.

Journal Article↗
PubMed1999

New Vibrational Numbering and Potential Energy Curve for the 3(3)Pig Electronic State of the Li2 Molecule.

An experimental study of the 3(3)Pig electronic state of 7Li2, using the Perturbation-Facilitated Optical-Optical Double Resonance (PFOODR) technique, was recently reported [A. Yiannopoulou et al., J. Chem. Phys. 103, 5898, (1995)]. However, due to the very small number of known 7Li2 A1Sigma+u approximately b3Piu window levels, only 13 ro-vibrational levels (spanning a range of vibrational levels designated upsilonx - 1 to upsilonx + 3 in that reference) could be observed. Dunham coefficients, based on the assignment upsilonx = 7, were found to fit the observed term values and give a qualitative fit to the intensities of the first six lines of the 3(3)Pig (upsilon = upsilonx, N = 11) --> b3Piu emission spectrum. However, due to the limited number of levels used in the fit, both the absolute vibrational numbering and the 3(3)Pig RKR potential curve obtained from the Dunham coefficients, must be considered to be uncertain. In the present work, we show that the previously reported 3(3)Pig RKR curve is unable to reproduce the experimental intensity distribution in the 7Li2 3(3)Pig (upsilonx = 7, N = 11) --> a3Sigma+u emission continuum. We report new experimental data for the 7Li2 3(3)Pig (upsilonx + 1, N = 11) --> a3Sigma+u bound-free continuum and discrete 3(3)Pig (upsilonx +/- 1, N = 11) --> b3Piu spectra obtained using the PFOODR experimental technique. We demonstrate that the correct vibrational numbering and an improved RKR potential curve can be obtained by analyzing the experimental term values in combination with all observed bound-free and discrete spectra. Finally, term values for four 6Li2 3(3)Pig ro-vibrational levels were obtained using PFOODR spectroscopy. The measured isotope shifts confirm the absolute vibrational numbering obtained from the present analysis. Copyright 1999 Academic Press.

Journal Article↗
PubMed1999

Rotational Pattern Difference in Resolved Fluorescence Spectra with Different Detection Schemes.

The relative intensities of rotational lines in resolved fluorescence spectra are dependent on the detection direction and the choice of the detection scheme when a grating monochromator is used. These differences arise from the spatially anisotropic distribution of the fluorescence, the rotational branch dependence of the fluorescence polarization, and the polarization dependence of the monochromator grating efficiency. Both the anisotropy of the emission and the rotational branch dependence of the fluorescence polarization are enhanced in double-resonance excitation schemes. In the present work, we analyze the relative intensities in the (7)Li(2) 1(3)Sigma(-)(g) --> 1(b)(3)Pi(u) and 1(3)Delta(g) --> 1(b)(3)Pi(u) resolved fluorescence spectra, observed following double-resonance excitation, for three different detection schemes. Copyright 1999 Academic Press.

Journal Article↗
PubMed1999

The 4(3)Pi(g) State of Na(2): Vibrational Numbering and Hyperfine Structure.

The Na(2) 4(3)Pi(g) state has been studied by continuous-wave (cw) perturbation-facilitated optical-optical double resonance (PFOODR) fluorescence excitation and resolved fluorescence spectroscopy. The absolute vibrational numbering was determined by resolved fluorescence to the a(3)Sigma(+)(u) state. The OODR excitation lines of the 4(3)Pi(g) (Kv, N) <-- b(3)Pi(u) (Kv(b)('), J') approximately A(1)Sigma(+)(u) (Kv(A)('), J') <-- X(1)Sigma(+)(g) (Kv", J") transitions show hyperfine splittings, and the hyperfine coupling scheme of the upper 4(3)Pi(g) levels is case b(betaS). Although this 4(3)Pi(g) state dissociates to the 3p + 3p atomic limit, it is a Rydberg state at a small internuclear distance, and the hyperfine splitting is caused mainly by the Fermi contact interaction of the varsigma(g)3s valence electron with the nuclei. The Fermi contact constant was determined to be b(F) = 218.3 +/- 3.9 MHz. Copyright 1999 Academic Press.

Journal Article↗
PubMed1999

Treatment of renal stones in Bulgaria in ancient times ('Hissarya' baths).

Well-known mineral baths in Bulgaria, 'Hissarya', are described. Their existence dates back more than 25 centuries. 'Hissarya' is an Arabic word meaning 'siege of a castle'. Remains of castle walls are the symbol of 'Hissarya' today. Every year more than 100,000 patients from Bulgaria and other countries visit 'Hissarya'. From the time of the Thracians and the Roman Empire until now renal stones have been successfully treated by drinking the mineral water and by taking baths. The Roman Emperor Septimius Severus (193-211) visited 'Hissarya' every spring to treat his renal disease.

Balneology↗
PubMed1990

[Creatine kinase in patients with diabetes mellitus].

In 72 diabetic patients the serum levels of creatine kinase (CK) and its isoenzyme MB were examined together with the levels of other enzymes most frequently examined in practice. A transient elevation of the CK level, mainly of the muscular isoenzyme, was found in 12.5% of the patients examined. In none of these patients lesions of the myocardium, thyroid gland or the striated muscles, which could explain the rise of CK, were found. There was a moderate correlation between the degree of glycemia and the CK elevation but there was no such correlation with other enzymes. With improvement of the carbohydrate metabolism the CK level became normal. The possible pathogenic mechanisms for the rise of the CK level in diabetes mellitus are discussed. The limited number of the patients examined does not allow final conclusions about these mechanisms.

Biomarkers↗
PubMed1990

[Treatment of obesity with a very low-energy dietetic regimen--the endocrine parallels].

25 patients with various degree of obesity treated with a very low-caloric diet (Dresden diet) were followed up dynamically. By an average clinical stay of 22 days a satisfactory reduction of the body mass with mean 6.6 kg was achieved at mean reduction of the body mass index from 34 to 31. The blood sugar level, immunoreactive insulin in the course of the oral glucose tolerance test, the 24 h rhythm of the plasma cortisol and the aldosterone level at rest and in orthostatic position at the beginning and the end of the dietetic treatment were followed up. The results achieved are discussed in relation to the reduction of the body mass.

Adolescent↗
PubMed1989

[The TRH test using the Bulgarian preparation Protilerin in the diagnosis of hyperthyroidism].

The stimulation test--TRH test was carried out with the Bulgarian drug "Protilerin" in 63 patients (Basedow's disease--53 patients, basedoid goiter--5 patients, infiltrative ophthalmopathy--5 patients) and in 20 healthy controls. The healthy controls showed normal reaction to the stimulation. All patients with hyperthyroidism showed a suppressed response to the stimulation. In two of the patients with euthyroid infiltrative ophthalmopathy the response was similar to that of the healthy controls. The Bulgarian drug Protilerin is suitable for the performance of the TRH test in the diagnosis of hyperthyroidism.

Adult↗
PubMed1988

[Our experience in treating diabetes mellitus with the preparation Minidiab].

55 patients with non-insulin-dependent diabetes mellitus were treated with the new oral drug Minidiab. In 58.2% of the patients the carbohydrate metabolism was influenced. No relation between the immunoreactive insulin increase and the effect of the treatment was found. An extrapancreatic action of the drug is suggested as its hypoglycemic activity.

Adult↗
PubMed1986

[Autonomic cardiac neuropathy in diabetes mellitus].

A total of 90 patients were studied (47 females and 43 males)--with insulin-dependent diabetes--81 subjects and with non-insulin-dependent type--9 subjects. Eighty five of them were aged between 15 and 45 years and 5--over 45. A total of 33 healthy subjects (18 females and 15 males) served as controls. Test for observation of heart rate at test, the changes in P-P intervals after a single deep breathing and 6 deep breathings within I min were used as well as the test with standing up and Valsalva's maneuver. Recording was realized by a 6-channel electrocardiograph, type "Hellige". Statistically significant was established to be the basal heart rate in the patients with diabetes, inhibited sinus arrhythmia in 26.6 to 45.5% of the cases with both tests with deep breathing, pathological Valsalva's ratio in 13.4% of the cases and borderline pathological in 32.9%. The results from the test with standing and calculating the index 30:15 have no statistically significance as compared with the controls. Our studies suggest changed cardiocirculatory responses in the patients with diabetes, associated with affected parasympathetic innervation of the heart.

Adolescent↗
PubMed1985

[Diabetes mellitus with atrophy of the mm. interossei of the upper extremities].

Two cases are described with atrophy of the interosseous muscles of the upper extremities as a manifestation of peripheral diabetic polyneuropathy with a main motor damage. In both cases, a long-term diabetes is concerned--insulin-independent type, perorally treated. Retino- and nephropathy were present in the patients as well as macroangiopathy in one of the cases. The lesions were in the frame of generalized polyneuropathy of the four extremities, confirmed, in one of the cases, by electromyographic examination. No changes in muscular atrophy were observed by the treatment carried out.

Diabetic Neuropathies↗
PubMed1985

[Multiple gangrene of the digits in a female patient with liver cirrhosis, diabetes mellitus and cryoglobulinemia].

A case is described with multiple gangrene of the fingers of a female, aged 55, with confirmed cirrhosis of liver and diabetes mellitus. Cryoglobulins were established in the serum. A disturbed immunological balance was present and the family loading with collagenosis raises the problem of genetic moments of the disturbed homeostasis. The existing diabetic microangiopathy, histologically confirmed by biopsy of skin and subcutaneous tissue, brings forward the question of the complex pathogenesis of gangrene. At the end of her stay in the clinic, the patient developed cerebral apoplexy.

Brain Ischemia↗
PubMed1985

[Lipoatrophic diabetes with hypertrophic subaortic stenosis].

A rare case is described of the combination of lipotrophic diabetes with hyperrophic subaortic stenosis in a young female. The authors announce the good results from the administration of bromorgocryptin for the reduction of the considerable hyperlipoproteinemia in the patient. The scare experiences in literature from the administration of the preparation is emphasized as well as the difficulties in the explanation of its mechanisms of action, at the present stage of our knowledge.

Adult↗