Use of SEM/EDX methods for the analysis of ambient particulate matter adhering to the skin surface.

BACKGROUND: The skin is exposed to numerous particulate and gaseous air pollutants. The ones that need particular attention are the particles that adhere to the skin surface, which can later cause direct skin damage. This study aimed to characterize air pollution (AP) particles adhered to the human skin by using scanning electron microscopy (SEM) combined with X-ray dispersive energy spectrometry (EDX). METHODS: Tape stripping was performed from six healthy volunteers exposed to urban AP to collect stratum corneum samples from the cheeks and forehead. The samples were analysed using SEM equipped with EDX system with a silicon drift detector at an accelerating voltage of 20 keV. After the preliminary examination, the particles were located and counted using 1000× magnification. Each particle was analysed, increasing magnification up to 5000× for precise dimension measurement and elemental composition analysis. At least 100 fields or a surface of approximately 1 mm2 were examined. RESULTS: Particles adhered to the skin were identified in all samples, with a particle load ranging from 729 to 4525. The average area and perimeter of all particles identified were 302 ± 260 µm2 and 51 ± 23 µm subsequently, while the equivalent circular diameter was, on average, 14 ± 6 µm. The particles were classified into ten groups based on morphology and elemental composition. Chlorides were the most numerous particle group (21.9%), followed by carbonaceous organic particles (20.3%), silicates (18%), carbonates (16.4%), metal-rich particles (14%), and a minor number of bioaerosols, quartz-like, and fly ash particles. CONCLUSION: The SEM-EDX analysis provides evidence of the contamination of exposed skin to various airborne PM of natural or anthropogenic origin. This method may provide new insights into the link between exposure to AP and AP-induced skin damage.

Development of a negative ion-based neutral beam injector in Novosibirsk.

A 1000 keV, 5 MW, 1000 s neutral beam injector based on negative ions is being developed in the Budker Institute of Nuclear Physics, Novosibirsk in collaboration with Tri Alpha Energy, Inc. The innovative design of the injector features the spatially separated ion source and an electrostatic accelerator. Plasma or photon neutralizer and energy recuperation of the remaining ion species is employed in the injector to provide an overall energy efficiency of the system as high as 80%. A test stand for the beam acceleration is now under construction. A prototype of the negative ion beam source has been fabricated and installed at the test stand. The prototype ion source is designed to produce 120 keV, 1.5 A beam.

Analysis of hematopoiesis dynamics in residents of Techa riverside villages chronically exposed to nonuniform radiation: modeling approach.

A profound approach to the analysis of clinical data on the dynamics of major hematopoietic lineages (granulocytopoietic, thrombocytopoietic, and erythrocytopoietic systems) in chronically irradiated humans is proposed. It is based on recently developed mathematical models of these systems in humans, which enable one to study and interpret clinical hematological data. The developed approach is applied to the analysis of statistically processed clinical data, which were obtained under hematological examinations of residents of Techa riverside villages. These people were exposed to chronic irradiation with varying dose rate due to the radioactive contamination of the river basin by the Mayak Production Association. In the course of modeling studies, the relationship between the dynamics of aforementioned systems in examined individuals and the variation of chronic exposure dose rate over the considered period of time is revealed. It is found that the models are capable of reproducing common regularities and peculiarities of the dynamics of systems on hand, including the decreased stationary levels of blood cell concentrations during the period of maximum radiation exposure, the recovery processes during the period of decrease of exposure dose rate, and the prevalence of younger bone marrow granulocytopoietic cells over more mature ones during the entire period. The mechanisms of such effects of chronic irradiation on the hematopoietic lineages are revealed on the basis of modeling studies. All this testifies to the efficiency of employment of the developed models in the analysis, investigation, and prediction of effects of chronic irradiation on human hematopoietic system.

[Status of hemapoiesis in residents of the Techa riverside villages in the period of maximum radiation exposure. Report 1. Evaluation of the cellular composition of peripheral blood and the role of comorbidities in the oppression of hemapoiesis].

Residents of the Techa riverside villages chronically exposed to ionizing radiation (the average dose rate in 1951-1956 was 0.047 Gy/year, the maximum reached 2.44 Gy/year) developed marked changes in the cellular composition of peripheral blood. The maximum reduction of peripheral blood counts occurred in the years 1951-1953, after which the beginning of the restoration of cellularity to the control level was observed. The dose rate at this point (1956) was about 0.02 Gy/year. The factors of radiation and non-radiation nature (gender, the age at the onset of exposure, health related disorders) in different combinations affect the number of peripheral blood cells. The influence of dose rate of a chronic radiation exposure on a platelet count takes precedence over other factors. The factors of gender and dose rate determine the number of erythrocytes in exposed persons. The changes accompanying the health status and dose rate significantly affect the number of neutrophils. The influence of comorbidity, age and dose rate on the number of monocytes was noted. A lymphocyte count was mainly determined by the age at the onset of exposure and concomitant diseases. A joint influence of chronic radiation exposure and concomitant diseases increases a mutual action on erythro- and thrombocytopoiesis. The decrease of the dose rate was followed by a gradual predominance of the somatic disease influence on leukocyte (neutrophils, lymphocytes and monocytes) counts.

[Status of hemapoiesis in residents of the Techa riverside villages in the period of maximum radiation exposure. Report 2. Influence of exposure dose and dose rate of red bone marrow as well as modifying factors on the frequency of cytopenia and cytosis].

The purpose of this study is a retrospective estimation of the influence of dose and dose rate of the red bone marrow chronic radiation exposure in combination with various modifying factors (gender, age, comorbidity) on the frequency of deviations from normal values of the results of peripheral blood investigation in humans exposed on the Techa River. The results of investigation show that humans chronically exposed to radiation can develop marked changes in the cellular composition of peripheral blood characterized by a tendency to cytopenia (signs of the decompensation of hemopoiesis). The tendency to cytopenia can be identified earlier in the lymphoid germ, and later in platelet and erythroid lines. A high lability of granulocytes under the influence of various, often infectious, factors is the cause of the lack of statistically significant differences in terms of frequency of neutropenia. Several non-radiation factors (gender, age, health status) in combination with radiation exposure could have a modifying influence on hematopoiesis, which contributed to the disruption of adaptation processes and the development of conditions characterized by a tendency to cytopenias in exposed individuals. The red bone marrow dose rate reduction resulted in a gradual decrease in the frequency of erythrocytopenia, thrombocytopenia, neutropenia and lymphocytopenia in the group of exposed population. Increased frequencies of erythrocytosis, thrombocytosis, lymphocytosis, monocytosis and neutrophilia were observed when the median dose rate was reduced to the level of 0.024 Gy/year (in the year 1956), which could be regarded as activation of regenerative processes in hematopoiesis.

[Efficiency and safety of the intravenous application of esomeprazole (nexium - Astra Zeneca) in high risk patients subjected to mechanic ventilation].

INTRODUCTION: The aim of the research was to determine the effectivity and the safety of the intravenous application of Esomeprazole (Nexium - Astra Zeneca) like prevention of the development of stress-ulcers of the gastric mucous with high risk patients at ICU with mechanic ventilation. PATIENTS AND METHODS: 47 patients subjected to mechanic ventilation over 48 hours with availability of just one more risk factor for development of stress-ulcers of gastric musous were included in the study. Samples of gastric juice for determination of the acidity and presence of fresh erythrocytes and microbiological cultures from gastric contents, wash away of the mouth cavity and tracheal aspiration were tested on the 1st, the 3rd and the 5th day from the start of the treatment. At the end of the therapy there has been determinated the outcome - survivor or died and total quantity of the haemotransfusions. RESULTS: The acidity of the gastric juice changed in the range over pH 5 during the 24 hours by the application of esomeprazole. Fibrogastroscopic examinations were performed of patients who were found to have fresh erythrocytes in the gastric contents. No one was registered with bleeding of the gastric mucous. The isolated microorganisms of the gastric juice and wash away of mouth cavity were identical with those of tracheobronchial aspiration in about 13 %. CONCLUSIONS: In our study the application of esomeprazole i.v. was effective and safe approach for profilaxy of the stress-ulcers and the bleeding of the gastric mucous. Comparative studies with H2-blockers and sucralfat are necessary for clarifying and objectifying the significance of the microbiologic isolates of the gastric contents and wash away from mouth cavity and their relation to the development of nosocomial pneumonia.

[Algorithms for procedures in thoracic trauma]. / Algoritum na povedenie pri travmi v toraksa.

The study includes 1127 injured with thoracic trauma, 23 percent of them with polytrauma. The worse thoracic trauma were these with formed flail chest with pleural and lung complications, accompanied by severe disfunction in circulation and biomechanics of breathing. The application of minimal surgical procedures like pleural punctures and drainage of pleural cavities with aspiration achieved good results. Thoracotomy was performed on clear indications (unstoppable bleeding, large ruptures of lung parenchyma, suppurative lung haematoma, cardiac tamponade, rupture of major airways, rupture of diaphragm, rupture of oesophagus and coagulated haemothorax). The achieved mortality of 5.9 percent is an excellent index suggesting a choice of treatment.

[Mediastinitis--diagnostics and surgical treament]. / Diagnostika i lechenie na ostrite mediastiniti.

During the last 10 years we have treated 23 patients with acute mediastinitis. The patients' age, sex, medical status, causes of the infection, bacteriology, chest X-ray and computed tomography scan findings, surgical intervention, complications, survival, and other clinical parameters were reviewed.

[Uncommon tracheal trauma. Diagnosis and treatment]. / Lechebnodiagnostichen podkhod pri riad vid travma na trakheiata.

The trauma of the trachea and bronchi are extremely rare, in 0.6 to 3 per cent of the patients with chest trauma. Most common are the longitudinal lesions localized in the membranous part. Following are the transversal lesions localized between two cartilaginous rings and in 20 per cent of the cases total circular lesions with dislocation of the two ends are found. A review of the clinical signs, the complications, the diagnosis and the successful operative treatment of a patient with the latter particularly rare traumatic injury of the trachea is presented.

[Spontaneous esophageal perforation--a case report and review]. / Spontanni perforatsii na khranoprovoda--s prinos ot edin sluchai i obzor.

The quick diagnosis is decisive for the outcome of the treatment of patients with esophageal perforation because of the serious complications--mediastinitis, empyema and sepsis. These are the main causes for the high mortality of up to 60 per cent of the patients with esophageal perforation. The difficulties for the particular operative tactics rise from the late diagnosis. These are the most problematic moments of the spontaneous esophageal perforation (Boerhaave's syndrome) management. A review of the clinical signs, the complications, the diagnostics and the successful operative treatment on a patient with Boerhaave's syndrome performed on the 10th day after the incident is presented.