PubMed Health⌕ Search

Biomedical subjects

N Georgiev

Publications and source records attributed to N Georgiev.

At least 19 recordsLinked to original sources
PubMed2002

Two crossovers in the Pseudogap regime of YBa 2Cu 3O (7-delta) superconductors observed by ultrafast spectroscopy.

We have investigated the temperature dependence of the optical reflectivity on a femtosecond scale in a near optimally doped YBa 2Cu 3O (7-delta) superconductor. The combined study of the lattice and carrier dynamics at temperatures above T(c) allows us to identify two crossover temperatures in the normal state, giving evidence for an inhomogeneity of the pseudogap regime. These crossovers exhibit a clear hysteresis behavior depending on the direction of temperature change. The carrier and lattice dynamics within the crossover regimes show distinct differences from and similarities to the superconducting state, which may help in choosing between the competing theories for the pseudogap state.

Journal Article↗
PubMed1988

[The survival and treatment of patients with systemic connective tissue diseases (research based on data from the II Internal Medicine Department of the Main Community Hospital in Stara Zagora for 1976-1986)].

The experience of the district hospital in Stara Zagora in the treatment of patients with systemic connective tissue diseases for the period 1976-1986 is presented. The study includes 47 patients with systemic connective tissue diseases: 22 patients with systemic lupus erythematodes (19 alive, 3 deceased); 18 patients with systemic progressive sclerodermia (16 alive, 2 deceased); 5 patients with dermatomyositis (4 alive, I deceased); 2 patients with nodal polyarteriitis (I alive, I deceased). The characteristic of the course of the disease is discussed--acute, subacute and chronic. The treatment applied and the cause of death are analyzed. The mean duration of the disease from the first clinical signs for the alive and the deceased is as follows: systemic lupus erythematodes--13.7 years for the alive and 12.5 years for the deceased patients; systemic progressive sclerodermia--16.6 years for the alive and 3.0 years for the deceased patients; dermatomyositis--3.7 years for the alive, 1.5 years for the deceased patients; polyarteritis nodosa--5 years for the alive, 2 years for the deceased patients. The conclusion is reached that the contemporary treatment can lead to a remission even in severe cases and life-threatening forms of the disease.

Bulgaria↗
PubMed1986

[Scintigraphy of the myocardium in postinfarct cardiac fibrosis].

The authors conducted a scintigraphic study of 50 patients with a 2-7 year history of myocardial infarction and clinical findings of postinfarction myocardiofibrosis. 201Tl-chloride with the activity of 74 MBq and the Picker 500 magna-scanner (USA) were employed. Four projections were used in the study. It was stressed that in anterior myocardial infarction the best positions were the front and front-left-oblique ones (30 and 45 degrees) and in posterior myocardial infarction the front-left-oblique one (75 degrees). A conclusion has been made as to a high sensitivity of the method to confirm postinfarction myocardiofibrosis represented in the form of a zone with disturbed perfusion. The authors underlined a high value of the method in cases accompanied by conductive disorders as the information value of a scintigram exceeded that of ECG.

Adult↗
PubMed1986

[Block of the anterior median branch of the bundle of His].

Present-day data (histological, electrocardiographic, vectorcardiographic and coronarographic) are presented in the paper, forming the concept of quadrifascicular structure of the conduction system of the heart. The criteria are indicated, on which the diagnostics of blocking of anterior-medial ramification of the left branch of His bundle is based. The author presents 4 of his own observations, illustrating the variety of the manifestations of the blocking of the anterior-medial ramulus--intermittent blocking, combination with blocking of anterior-upper ramulus, blocking in the presence of only septal fibres of the ramulus and blocking with spreading of the fibres also in the anterior-septal region of the left ventricle of heart.

Aged↗
PubMed1982

[Atrial dissociation].

Auricular dissociation is a rare and interesting arrhythmia, characterized by ectopic auricular thythm, independent of the basic one. The basic and accessory auricular rhythm never interfere in between, the latter always being restricted to a smaller part of auricle and is almost never conducted to ventricles. It is most frequently a slow rhythm, and is rarely recorded as auricular fibrillation and undulation of one auricle, or as auricular tachycardia. Almost always the auricular dissociation develops in critical states and most frequently appears several hours prior to a lethal end. A typical case of auricular dissociation is described in a male subject with active myocardial infarction that originated several hours prior to the lethal end of the patient. In our case a rare variant of auricular dissociation is concerned, combined with AV dissociation.

Arrhythmias, Cardiac↗
PubMed1980

[Multifocal atrial tachycardia].

The multifocal auricular tachycardia is one ectopic rhythm anomaly, conditioned by a constellation of biochemical and mechanic factors. The presence of four basic ECG-criteria, characterizing the origination of heterotropic impulses from different auricular foci are necessary in order to admit that anomaly. The author has followed up seven cases, presenting characteristic ECG-records and clinical states, when multifocal auricular tachycardia arises. The considerable resistance of the applied antiarrhythmic therapy was stressed upon as well as the high mortality in case of that rhythm disorder, usually occurring in patients with advanced heart diseases.

Adult↗