Vol 37, No 6 (2020)

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Full Issue


In memory of Irina Petrovna Koryukina


Irina Petrovna Koryukina was born on February 21, 1953 in Perm in a family of doctors. In 1970 she graduated with a gold medal from school number 22 with in-depth study of the French language, in the same year she entered the medical faculty of the Perm State Medical Institute (PSMI), in 1976 she graduated with honors. From 1976 to 1978 she studied in residency, and from 1978 to 1981 - in graduate school at the Department of Faculty Pediatrics, PSMI. Since 1981 - Assistant, and from 1985 to 1992 - Associate Professor of the Department, since 1992 - Head of the Department of Pediatrics of the Faculty of Advanced Training for Physicians. From 2002 to 2005 - vice-rector for scientific work of the Perm State Medical Academy, since 2005 - rector.

Perm Medical Journal. 2020;37(6):

In memory of Yakov Saulovich Tsimmerman


On November 3, 2020, at the age of 99, an outstanding Russian scientist-gastroenterologist, Honored Scientist of the Russian Federation, founder of the Perm School of Gastroenterology, Honorary Professor of the Russian Gastroenterological Association and Perm Medical University Yakov Saulovich Tsimmerman died.

Perm Medical Journal. 2020;37(6):

In memory of Andrey Valentinovich Nikolenko


Andrey Valentinovich Nikolenko was born on February 26, 1972 in the city of Chusovoy, Perm Region, into a family of medical workers. Graduated from the medical faculty of the Perm State Medical Academy in 1994, clinical residency, full-time postgraduate study. Academic degree: candidate of medical sciences, academic title: associate professor (2005). Since 2001 - Assistant at the Department of Hospital Surgery, Anesthesiology and Reanimatology with the course of Oncology and Surgery at FUV. In 2008, he organized and headed the Department of Mobilization Preparation of Health Care and Disaster Medicine. Since 2015, he headed the Department of Anesthesiology and Reanimatology. Since 2018 - the Department of Anesthesiology, Reanimatology and Emergency Medicine. During his work, the head with his help trained more than 100 specialists who graduated from residency, the negative growth in the staff of anesthesiologists-resuscitators was stopped (the staff shortage decreased by 30% in four years).

Perm Medical Journal. 2020;37(6):

Original studies

Contribution of changes in iron metabolism in pathogenesis of chronic diffuse liver diseases

Shchekotova A.P., Bulatova I.A.


Objective. To assess the role of iron metabolism changes in the pathogenesis of chronic diffuse liver diseases (CDLD). Assessment of the hepatic fibrosis progression and the most significant factors, influencing it, is still an actual target of modern medicine. A certain interest from the point of view of complex approach to studying the mechanism of development and progression of fibrosis is the determination of serum markers of iron metabolism.

Materials and methods. The study included 170 patients with CDLD: 150 with chronic viral hepatitis C and 20 with alcohol hepatic cirrhosis (AHC). Iron metabolism indices and functional hepatic biochemical tests were studied. Expression of hepatic fibrosis in hepatitis was estimated by means of the liver density index with the scale METAVIR using the data of ultrasound elastography (Fibroscan 502, Echosens, France); fibrosis development rate was calculated with T. Poynard method. The control group enclosed 100 persons.

Results. There was revealed a significant elevation of the blood ferritin concentration among patients with chronic hepatitis up to 107.9 [31; 250] ng/ml compared with the control (22.0 [11; 33] ng/ml) and to 325.8 [209; 401] ng/ml in patients with AHC.

Conclusions. Progression of fibrosis into cirrhosis in patients with CDLD is interconnected with iron metabolism disorders in the form of increased ferritin concentration, which correlates with the parameters of liver lesion severity that confirms a direct involvement of iron metabolism disorders in CDLD pathogenesis.

Perm Medical Journal. 2020;37(6):5-12
pages 5-12 views

Features of amniotic fluid microbiota in full-term pregnancy

Kaganova M.A., Spiridonova N.V., Medvedchikova-Ardiya L.K.


Objective. To study the microbial landscape of amniotic fluid in physiological process of full-term pregnancy. Recently, after publication of a number of studies regarding human microbiota (The Human Microbiome Project – HMP), there occurred a change in paradigm on absolute sterility of fetal membranes and amniotic fluid in physiologically developing pregnancy.

Materials and methods. At the City Clinical Hospital № 1 named after N.I. Pirogov, during elective cesarean section of 19 pregnant women (at the terms of 37–41 weeks) with intact fetal membranes, an amniotic fluid of the following microorganisms was taken by means of PCR-PB: Lactobacillus spp., Enterobacteriaceae, Streptococcus spp., Staphylococcus spp., Gardnerella vaginalis / Prevotella bivia / Porphyromonas spp., Eubacterium spp., Sneathia spp. / Leptotrihia spp. / Fusobacterium spp., Megasphaera spp. / Veillonella spp. / Dialister spp., Lachnobacterium spp. / Clostridium spp., Mobiluncus spp. / Corynebacterium spp., Peptostreptococcus spp., Atopobium vaginae, Mycoplasma hominis, Ureaplasma (urealyticum + parvum), Candida spp., Mycoplasma henitalium.

Results. The general bacterial mass (GBM) of amniotic fluid in intact fetal membranes is 103,02 Ge/copies, in 47.4 % of cases the amniotic fluid is sterile. Microbiota is most often presented by Enterobacteriaceae spp. – 37 %, the share of the rest, identified bacteria is 28 %, the share of “unknown” is 35 %.

Conclusions. In case of physiologically developing pregnancy and intact fetal membranes, the general bacterial mass is low (GBM = 103,02 ± 345 Ge/ml). In the intact amniotic sac the most typical microorganisms living in amniotic fluid are Enterobacteriaceae spp. (37 %), the rest are presented in single instances. The presence of the representatives of anaerobic vaginal dysbiosis as well as lactobacilli is not typical for the intact fetal membranes.

Perm Medical Journal. 2020;37(6):13-24
pages 13-24 views

Construction of integral index for comprehensive assessment and analysis of risk factors for lower limb varicose veins during pregnancy

Shevlyukova T.P., Chabanova N.B., Ermakova A.A., Ermakova P.A.


Objective. To develop a model of an integral index for complex assessment of varicose vein risk factors and estimate the influence of pregnancy on the occurrence of chronic vein diseases. Varicose veins (VV) and chronic venous insufficiency are one of the most widespread human diseases. This pathology in pregnancy has a clear picture, which is quite different from varicose veins in non-pregnant women.

Materials and methods. Analysis of 1974 individual medical cards of pregnant women and puerperas of Maternity Hospital № 2 for the period of 2016–2019 was carried out. Out of them, 456 cards had a diagnosis of varicose veins of the lower limbs. The method was based on statistical analysis and integral indices.

Results. The following risk diapasons were determined: low risk (favorable prognosis) – 0.44–0.85; medium risk (favorable prognosis is possible) – 0.86–1.28; high risk (unfavorable prognosis) – 1.29–2.13. The quantity of pregnancies is not an unfavorable prognosis for women. Long statistical loads give unfavorable prognosis (1.34–1.43); family predisposition is an unfavorable prognosis (1.66); lifting loads depending on the quantity in grams (1000 – favorable sign; 5000–10 000 – unfavorable (1.21–1.870)); wearing tight clothes is not an unfavorable prognosis (0.88); hypodynamia – medium risk (1.14); diet – low and medium risk (0.75–0.95), obesity – high risk (1.24–2.15).

Conclusions. The obtained results permitted to detect the most significant risk factors for varicose veins during pregnancy. Medium and high-risk indices are the following: long statistical loads, family predisposition, lifting loads, hypodynamia, diet and obesity. They influence the development of varicose veins. There is a possibility to present a prospective prognosis for pregnant women and develop a complex of measures to decrease risks for chronic vein diseases taking into account individual features of patients.

Perm Medical Journal. 2020;37(6):25-32
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Species diversity and biological properties of dominant species of causative agents of poststernotomic infectious complications in cardiac surgery

Kasatov A.V., Gorovits E.S.


Objective. To study the microbial and biological properties of the dominant species of causative agents of infectious and inflammatory complications after cardiac surgery. Infectious and inflammatory complications (IIC) developing after cardiac surgery with sternal approach such as thoracic and rib osteomyelitis, sterno-mediastinitis are severe life threatening states.

Materials and methods. Bacteriological study of the sternal wound discharge from 178 patients with different infectious and inflammatory complications after sternotomic open-heart surgeries was conducted. Biological properties of isolates were investigated.

Results. There were detected 242 strains of microorganisms referring to different taxons. Gram-positive bacteria, in particular, S. aureus and S. epidermidis prevailed. Out of gram-negative bacteria, prevailed P. aeruginosa and E. coli. All isolates S. aureus and P. aeruginosa possessed different factors of virulence and persistence including ability to biofilm formation. Carbapenems displayed the greatest bactericidal activity in relation to S. aureus and P. aeruginosa.

Conclusions. The obtained data permit to optimize the preoperative preparation of cardiac surgery patients.

Perm Medical Journal. 2020;37(6):33-41
pages 33-41 views

Influence of genetic characteristics of Helicobacter pylori on pathomorphology of gastric mucosa in young persons with chronic gastritis

Spivak E.M., Manyakina O.M., Akkuratova-Maksimova I.S.


Objective. To evaluate the effect of the genetic characteristics of Helicobacter pylori on the nature of pathomorphological disorders in the gastric mucosa in chronic Hp-associated gastritis in young people.

Material and methods. Forty-two adults (25 men and 17 women) aged 19 to 40 years with Hp-associated chronic gastritis were examined. The severity and activity of inflammation, as well as the presence of atrophy and intestinal metaplasia were determined in gastrobioptates. Genetic typing of Hp was performed for 16 pathogenicity factors of infect: CagA, CagM, CagT, CagH, CagC, CagF, CagE, VacAs1 and As2, IceA, Baba; HpaA; OipA, AlpB; UreB and UreI using polymerase chain reaction.

Results. Pathogenic Hp strains were detected in 59.5 % of patients. Factors of adhesion – HpaA (83.3 %), OipA (81 %), and AlpB (83.3 %) were identified with the highest frequency. In 57.1 % of cases, cytotoxin of the Cag group was detected, and 54.8 % of patients had a positive CagA-status. The VacA S1 allele was registered in 73.8 %, VacA S2 in 4.8 %, IceA in 38.1 %, and BabA in 45.2 % of cases. The presence of Hp strains in the gastric mucosa, which have three or more pathogenicity island genes, significantly increases the severity and activity of the inflammatory process, revealing signs of moderate atrophy of the digestive tract and intestinal metaplasia.

Conclusions. Colonization of the gastric mucosa in young patients with Hp-associated chronic gastritis by highly pathogenic Hp strains leads to severe violations of its morphology.

Perm Medical Journal. 2020;37(6):42-47
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Personification of nordic walking course in children with bronchial asthma depending on physical health level and disease control

Kuzina E.N., Spivak E.M., Nezhkina N.N.


Objective. To evaluate the effectiveness of a personalized Nordic walking course in children with bronchial asthma.

Material and methods. In conditions of a local sanatorium, 60 children aged 8–14 years with atopic bronchial asthma in remission were examined, 30 patients received the usual set of health-improving measures (comparison group), 30 patients additionally underwent a course of sports walking, personalized depending on the degree of asthma control and the level of physical health (main group). To evaluate it, the method of L.G. Apanasenko was used. Indicators of external respiration, abdominal and back muscle strength, physical performance, and Robinson and Rufier indices were determined. The children were examined twice: before and after the rehabilitation course. The dynamics of functional indicators was expressed as a percentage increase in relation to the initial values.

Results. It was found that 36.7 % of patients had a low, 53.3 % average and only 10 % high level of physical health. Only 10 % had a complete asthma control, and 90 % of children had a partial control. The use of a personalized sports walking course helped to improve the functional parameters of external respiration, muscular and cardiovascular systems. In the comparison group, the positive dynamics of most of functional indicators was significantly less obvious.

Conclusions. The course of Nordic walking in children with bronchial asthma at the stage of rehabilitation should be personalized taking into account the level of physical health and the degree of disease control. This technology in this category of patients has a significant positive health-strengthening effect, which is manifested by improving the functional state of the muscular, respiratory and cardiovascular systems.

Perm Medical Journal. 2020;37(6):48-53
pages 48-53 views

Epidemiology and clinical features of congenital malformations of uri-nary system organs in conditions of environmental distress

Pukhova T.G., Chirkova O.N., Sitnikova E.P., Dashichev K.V., Leontiev I.A.


Objective. To establish the features of epidemiology and clinical manifestations of congenital malformations of the urinary system in the zone of environmental distress.

Material and methods. We analyzed the overall prevalence of nephropathies and the proportion of congenital malformations of the urinary system in the dynamics from 2001 to 2019; 697 patients aged 1–18 years were examined with assessment of clinical and anamnestic, laboratory, instrumental and radiological data in accordance with diagnostic standards and protocols. We studied the features of epidemiology and clinical manifestations of congenital kidney and urinary tract diseases in an area with an unfavorable environmental situation.

Results. Over the past 2 decades, the general prevalence of nephropathies in the children's population has increased with an elevation in the proportion of congenital malformations of the urinary system. These indicators are significantly higher in an area with a high level of anthropogenic environmental pollution than in an area with a relatively favorable environmental situation. Features of congenital pathology of the kidneys and urinary tract in patients living in an environmentally unfavorable zone were revealed: the presence of mass deficiency, reduced resistance, combination with undifferentiated connective tissue dysplasia syndrome, more frequent attachment of microbial-inflammatory process, decreased concentration and evacuation function of the kidneys.

Conclusions. These features of epidemiology and clinical manifestations of congenital malformations of the urinary system in patients living in a region with a high level of environmental pollution should be taken into account when carrying out their medical support.

Perm Medical Journal. 2020;37(6):54-60
pages 54-60 views

Review of literature

Chronic obstructive pulmonary disease among workers exposed to in-dustrial aerosols: literature review

Panachevа L.A., Shpagina L.A.


The article presents a literature review regarding the formation of chronic obstructive pulmonary disease in conditions of the exposure of industrial aerosols. It shows a high frequency of occupational respiratory hazards, characterizes the diseases caused by air pollution with industrial and indoor pollutants, allergens and toxins in different occupational groups as well as basic conditions for development of dust pathology of the lungs.

Perm Medical Journal. 2020;37(6):61-70
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Pregnancy management tactics in fetal hemolytic disease. Literature review

Fedchenko M.V., Maslennikova Y.S.


Hemolytic disease of the fetus is one of the types of pathological abnormalities in the development of the fetus, the reason of which is isoimmune hemolytic anemia. Depending on the degree of severity of this pathology, it can influence the development of the fetus both in a mild form, practically leaving no trace and in a severe form, which can cause fetal death.

When carrying out a timely diagnostic research to detect this pathology, tactics of pregnancy management should differ, that will allow maintaining of pregnancy and ensure normal development of the fetus just until the moment of childbirth. To determine the tactics, which will be used during pregnancy management, it is necessary to identify not only the symptoms of hemolytic diseases of the fetus but its degree as well. Depending on the degree of severity of this disease, the activities will differ. If the disease is developing in a mild form, a pregnant woman is thoroughly observed and repeatedly diagnosed; if it is a severe form, intrauterine fetal blood transfusions are regularly conducted. The tactics of managing pregnancy with the detected fetal hemolytic disease will differ from the standard one and its right choice will ensure normal development of the fetus and term labor with minimum risks for both a mother and a child.

Perm Medical Journal. 2020;37(6):71-80
pages 71-80 views

Methods of diagnosis and technologies

Influence of suture technique in aortic valve replacement on occurrence of "Prosthesis-Patient" mismatch

Kadyraliev B.K., Arutyunyan V.B., Kucherenko S.V., Gorbunova E.A.


Objective. To determine the suture technique, which provides better hemodynamic indices in aortic valve replacement. Aortic valve AV) pathology is a widespread pathology among elderly persons and since the share of them increases every year, the number of surgeries for AV replacement is growing. Many factors can influence the hemolytic characteristics of AV prosthesis including construction of cusps and supporting ring. Suture technique can also influence the hemodynamic results of AV replacement. Conventional technique for attaching mechanical valve is an interrupted sealing suture.

Materials and methods. Patients who underwent AV prosthetics isolated prosthetics, prosthetics combined with coronary artery bypass grafting, with mitral valve repair, tricuspid valve repair or aortic prosthetics) over the period from January 2015 to September 2018 were studied. All statistical calculations were fulfilled using IBM SPSS Statistics 23.0 IBM Corp., Armonk, NY).

Results. Altogether, from January 2015 to September 2018, 439 patients underwent AV prosthetics; 321 patient 73.1 %) underwent isolated AV replacement. Unsealed technique had less frequency of occurrence of “prosthesis-patient" mismatch PPM), especially in the small aortic ring compared with the other suturing techniques. The suture type was the following: sealing and figure-of-eight suture and the number of sutures more than 16 were the risk factors for moderate and severe PPM in logistic regressive analysis; the suture technique was an independent risk factor for moderate and severe PPM.

Conclusions. An interrupted mattress unsealed suture permits to implant the AV prosthesis on the native fibrous ring of the valve with less frequency of occurrence of “prosthesis-patient" mismatch and promotes improvement of hemodynamics in patients with a small fibrous ring of the aortic valve.

Perm Medical Journal. 2020;37(6):81-88
pages 81-88 views

Diastolic function of left ventricle and importance of tissue doppler echocardiography in patients with coronary artery disease and type 2 diabetes mellitus after coronary artery bypass grafting

Magerramova L.I.


Objective. To analyze the influence of coronary artery bypass grafting CABG) on the diastolic function DF) in patients with coronary artery disease and type 2 diabetes mellitus with the preserved systolic function of the left ventricle LV) using tissue myocardial Doppler echocardiography TMD). The increase in the number of patients with type 2 diabetes mellitus type 2 DM) is one of the causes of a constant growth of the quantity of patients with coronary artery disease CAD). Taking into account the character of vascular bed lesion in patients with type 2 DM, revascularization of myocardium is significant for CAD treatment in this group of patients.

Materials and methods. The study included 122 patients diagnosed coronary artery disease mean age 58.8 ± 0.7 years, men – 81.1 %), who underwent coronary artery bypass grafting. The patients were divided into two groups: group 1–52 patients with CAD without type 2 DM; group 2–70 patients with CAD and type 2 DM. To assesss the diastolic function using pulse-wave Dollper PWD), there were estimated the velocity and time characteristics of the transmitral blood flow by means of TMD – myocardium movement velocity at the level of the mitral valve fibrous ring.

Results. The quantity of the detected patients with diastolic dysfunction DD) when using both PWD and TMD with type 2 DM – 85.7 %, without type 2 DM – 65.3 %) in both groups was higher compared with PWD applied alone with type 2 DM – 77.3 %, without type 2 DM – 59.6 %) p < 0.001).

Conclusions. Among CAD patients with preserved systolic function of the left ventricle, who underwent CABG and have type 2 DM, the use of both PWD and TMD is more preferable for revealing DD and dynamic postoperative observation.

Perm Medical Journal. 2020;37(6):89-101
pages 89-101 views

Laser thermotherapy or excision, what to offer to a patient with pilonidal disease?

Zolotukhin D.S., Krochek I.V., Sergiyko S.V.


Objective. To carry out a comparative analysis of the results of epithelial coccygeal course treatment using laser-induced interstitial thermotherapy LIT) under ultrasound control and traditional open excision. The high trauma rate of traditional operations in the epithelial coccygeal course ECC), the duration of hospital stay, pain syndrome force surgeons to search for new technologies in the treatment of this pathology.

Materials and methods. A retrospective analysis of the treatment results of 369 patients with ECC who were admitted to the clinic for elective surgery in the period from 2009 to 2019 was carried out. There were 264 men 71.5 %) and 105 women 28.5 %). The mean age was 26.9 ± 7.2 years. The patients were divided into 2 groups: 190 patients of the main group underwent surgery using a fiber-optic laser under ultrasound guidance, 179 patients of the comparison group underwent traditional radical excision of ECC with application of primary sutures or various types of plastic.

Results. The severity of pain syndrome after surgery in patients of the main group was 1.7 ± 0.6 points, in the comparison group 3.5 ± 1.3 points by a five-point visual analogue scale VAS) for pain. The duration of inpatient treatment in the main group was 1.8 ± 0.4 days, in the comparison group 11.5 ± 1.7 days. Moreover, in 197 76.1 %) patients of the main group, the operation was performed on an outpatient basis. The restoration of working capacity in the main group occurred after 5.2 ± 1.2 days, and in the comparison group – after 17.4 ± 2.8. After traditional operations, the relapse of the disease was noted in 11.7 %, and after laser treatment, slightly more than 12.1 %. Satisfaction with the results of treatment in the main group was noted in 95.1 %, and in the comparison group in 90 % of patients.

Conclusions. The obtained results of treatment allow us to recommend the technique of interstitial laser obliteration of the coccygeal cyst under ultrasound navigation developed in the clinic for widespread use in practical work of surgeons.

Perm Medical Journal. 2020;37(6):102-110
pages 102-110 views

Preventive and social medicine

Features of mental deadaptation formation in powder production workers

Kuzmina S.V., Garipova R.V., Yakhin K.K.


Objective. The aim was to assess the impact of production and non-production risk factors on the formation of mental health disorders in chemical workers.

Materials and methods. 201 employees of the main and 352 employees of the group of control were examined by a clinical method using a clinical structured psychiatric interview; questionnaires to identify additional non-production risk factors; questionnaire of neurotization. The calculations were carried out in the environment of the statistical system R. For modeling dependencies and calculating probabilities, logistic regression models were built, factor analysis was carried out.

Results. The dependence of the formation of prenosological mental disorders in workers on the temporal characteristics, the level of material support and the actual production factors was revealed. The proportion of persons with mental deadaptation MD) in the main group 72.5 %) and the group of control 27.5 %) significantly differ from each other p ≤ 0.001).

Conclusions. 1. The structure and the actual risk of MD formation among workers in the production of gunpowder is determined by harmful labor factors, depends on economic security, evolves depending on time characteristics. 2. For persons working under the influence of a chemical factor of the production environment in combination with explosive and fire hazardous works, the leading is astheno-vegetative symptomatology in combination with the personality type of conversion reaction. In the first 9 years of experience, general neurotic reactions are observed with a pronounced contribution from all scales, indicating the tension of adaptation mechanisms up to the formation of decompensation. With an increase in the length of time, the reactions are transformed into a conversion type of response according to the somato-vegetative type with a phobic radical and obsessions, and subsequently manifest themselves in relative independence from characterological reactions. 3. The degree of severity of reactions is characterized by variability, significantly overlapping the types of disorders that can be considered in the framework of «Other mood disorders» F38.0 and F38.1), which does not give grounds to classify them as F30-F34, since they are not sufficiently pronounced and severe.

Perm Medical Journal. 2020;37(6):111-122
pages 111-122 views

Clinical case

The case of takotsubo syndrome

Khovaeva Y.B., Kiryanova N.V., Zinkovskaya T.M., Ivanova N.V., Sosnin D.Y., Moiseenko N.P., Voronova E.I., Gladkov S.V., Gerasimova A.V.


The article describes the current understanding of the takotsubo syndrome concerning the issues of pathogenesis, differential diagnosis with acute coronary syndrome and strategy of management. There is presented our own clinical observation of a patient with an atypical form of cardiac dysfunction and myocardial geometry.

Perm Medical Journal. 2020;37(6):123-130
pages 123-130 views

Prolongation of viability of isolated skin explants by exposing them to their own transformed physical fields: experimental study

Nikityuk I.E., Afonichev K.A., Nikitin M.S., Kubasov V.A., Petrash V.V.


Objective. To study the effect of materials with optical-electrical properties on the survival of full-layer skin explants when they are isolated from the body with completely stopped trophic activity.

Material and methods. In rabbits of both sexes at the age of 5-6 months, full-layer skin flaps were excised from the back area, which were dissected into fragments-explants measuring 1.0×1.0 cm. All samples were thermostated for 2 days at 37 °C near transducers represented by aluminum foil sheets and silicon single crystals. In the first series of experiments, the explants were directly in contact with the transducers; in the second and third series, screens made of light-proof black paper and thin glass were installed between the explants and the transducers, respectively. In each series, the experiments were repeated 5 times with each transducer. After thermostating, the explant viability index was evaluated by histological method in points.

Results. In the first and second series of experiments, the highest survival rate of explants with a viability index from 3.6 to 3.8 points with a norm of 4.0 points) was revealed depending on the type of transducer. In series III, when screening silicon crystals with thin glass, the explant survival rate decreased slightly to 3.3 points. However, the screening of aluminum foil with glass led to a sharp decrease in the viability of explants to 0.2 points.

Conclusions. A long-term viability of skin explants can be explained only by the effect of their own physical fields on them produced by the biostructures of explants and transformed by interaction with nearby materials possessing optical and electrical properties.

Perm Medical Journal. 2020;37(6):131-142
pages 131-142 views

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