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The history of the growth of continental crust is uncertain, and several different models that involve a gradual, decelerating, or stepwise process have been proposed1-4. Even more uncertain is the timing and the secular trend of the emergence of most landmasses above the sea (subaerial landmasses), with estimates ranging from about one billion to three billion years ago5-7. The area of emerged crust influences global climate feedbacks and the supply of nutrients to the oceans 8 , and therefore connects Earth's crustal evolution to surface environmental conditions9-11. Here we use the triple-oxygen-isotope composition of shales from all continents, spanning 3.7 billion years, to provide constraints on the emergence of continents over time. Our measurements show a stepwise total decrease of 0.08 per mille in the average triple-oxygen-isotope value of shales across the Archaean-Proterozoic boundary. We suggest that our data are best explained by a shift in the nature of water-rock interactions, from near-coastal in the Archaean era to predominantly continental in the Proterozoic, accompanied by a decrease in average surface temperatures. We propose that this shift may have coincided with the onset of a modern hydrological cycle owing to the rapid emergence of continental crust with near-modern average elevation and aerial extent roughly 2.5 billion years ago.
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Planeta Tierra , Sedimentos Geológicos/análisis , Sedimentos Geológicos/química , Ciclo Hidrológico , Agua/química , Historia Antigua , Minerales/análisis , Minerales/química , Isótopos de Oxígeno/análisis , Agua de Mar/química , TemperaturaRESUMEN
The state health care policy in Russia is directed at improving medical care quality and population satisfaction with it. The functioning of medical organizations beloning to national health care system has determinative impact on population health. The increasing of level of organization of their functioning is imposible without target manpower policy, upgrading qualification and professionalism of health care workers. The purpose of the study was to analyze personnel potential of Oblast clinical hospital, as one of leading health care institutiond of the Astrakhan Oblast. The methodologies of statistical, logical and system analysis were applied. The study used method of continuous sampling and was carried out in 2012-2021. The information sources included forms of the Federal statistical monitoring â 30 "Information on the medical organization" and â 17 "Information on medical and pharmaceutical workers". The absolute and mean values, extensive parameters modeling structure and methods of dynamic series construction were applied. The study revealed positive dynamics of increasing of number of established posts on 33.7%. The number of physical persons of hospital medical personnel (the basic increase made up to 40%) increased. It resulted in decreasing of combining jobs coefficient and in increasing of staff efficiency employment. The women consisted 65.2% of all working physicians. The mean age made 43.2 years among phycians and 41.7 years among paramedical personnel. The ratio 1.5:1 of paramedical personnel to physicians in staff list is negative factor. Alongside, ratio of physical persons of paramedical personnel and physicians decreases. It testifies necessity of increasing both established posts and involvement of more physical persons to work on paramedical personnel rates.
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Instituciones de Salud , Hospitales , Humanos , Femenino , Adulto , Recursos Humanos , Personal de Salud , Atención a la SaludRESUMEN
Surgical community has not yet reached any consensus on the adequate treatment of gallstone disease with combined stones of the gallbladder and bile ducts. Endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic papillosphincterotomy (EPST) followed by laparoscopic cholecystectomy (LCE) have been considered the optimal treatment method for the past thirty years. Thanks to improvement of technologies and experience in laparoscopic surgery, many centers in the world offer simultaneous treatment of cholecystocholedocholithiasis, i.e. LCE and laparoscopic choledocholithotomy. Transcystical and transcholedochal extraction of calculi from the common bile duct is the most common. Intraoperative cholangiography and choledochoscopy are used to assess extraction of calculi while T-shaped drainage, biliary stent and primary suture of common bile duct are used to complete choledocholithotomy. Laparoscopic choledocholithotomy is associated with certain difficulties, requires some experience in choledochoscopy and intracorporeal suturing of common bile duct. There are many unresolved issues regarding the choice of laparoscopic choledocholithotomy technique depending on the number and dimensions of stones, diameter of cystic duct and common bile duct. The authors analyze literature data on the role of modern minimally invasive interventions in the treatment of gallstone disease.
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Colecistectomía Laparoscópica , Cálculos Biliares , Humanos , Cálculos Biliares/complicaciones , Colangiopancreatografia Retrógrada Endoscópica , Colangiografía/métodos , Conductos Biliares , Colecistectomía Laparoscópica/efectos adversos , Colecistectomía Laparoscópica/métodosRESUMEN
The review is devoted to the role of laparoscopic appendectomy in surgical management of acute appendicitis in pregnancy. We analyzed reviews, prospective and retrospective studies in the PubMed, Google, the Springer Link online library, the Cochrane Systematic Review databases. The results of laparoscopic and traditional treatment of acute appendicitis in pregnant women were assessed. We analyzed clinical, epidemiological features in these patients, differential diagnosis of acute appendicitis in pregnant women, indications and contraindications for endoscopic treatment, features of laparoscopic procedures. Comparative assessment of laparoscopic and open surgeries for acute appendicitis in pregnant women was carried out. We also estimated the influence of surgical treatment of acute appendicitis on subsequent course of pregnancy.
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Apendicitis , Laparoscopía , Femenino , Humanos , Embarazo , Enfermedad Aguda , Apendicectomía/efectos adversos , Apendicitis/diagnóstico , Apendicitis/cirugía , Laparoscopía/efectos adversos , Estudios Prospectivos , Estudios RetrospectivosRESUMEN
The review is devoted to laparoscopic technology in the treatment of perforated gastroduodenal ulcers. Searching for literature data was performed in the PubMed, Google, Springer Link online library, Cochrane Systematic Review databases. We analyzed reviews, prospective and retrospective studies devoted to various strategies in the treatment of perforated peptic ulcers. Demographic, clinical and epidemiological features of these patients, indications and contraindications for endoscopic suturing of perforations, features of laparoscopic procedures and causes of conversions to open surgery were studied. Finally, we compared the results of laparoscopic and open surgeries.
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Úlcera Duodenal , Laparoscopía , Úlcera Péptica Perforada , Úlcera Gástrica , Humanos , Úlcera Duodenal/cirugía , Úlcera Gástrica/cirugía , Estudios Retrospectivos , Estudios Prospectivos , Úlcera Péptica Perforada/diagnóstico , Úlcera Péptica Perforada/etiología , Úlcera Péptica Perforada/cirugía , Laparoscopía/efectos adversos , Laparoscopía/métodos , Resultado del TratamientoRESUMEN
The article presents a report on the findings of representatives of frenulate pogonophorans Nereilinum murmanicum in the northern and central parts of the Barents Sea, which significantly expands the range of this species and provides guidance on its distribution in this basin. Here we present the coordinates of new finds with an indication of the depth. Find points were associated with data on known and potential hydrocarbon deposits.
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Anélidos , Poliquetos , Animales , HidrocarburosRESUMEN
OBJECTIVE: To compare the results of endoscopic and open treatment of perforated gastroduodenal ulcers. MATERIAL AND METHODS: There were 445 patients with perforated gastroduodenal ulcers between 2013 and 2021. Endoscopic suturing of perforation was performed in 172 patients (38.7%), 273 ones underwent open surgery. RESULTS: Among 172 patients scheduled for endoscopy, 160 (93.6%) ones underwent laparoscopic suturing of perforation. Morbidity rate was 5.0% (n=8), postoperative mortality rate - 1.3% (n=2). Comparison of the outcomes after laparoscopic suturing of ulcers in 160 patients and open surgery in 134 patients showed that laparoscopy was followed by 2.5 times lower incidence of complications and 3 times lower postoperative mortality. CONCLUSION: Diagnostic laparoscopy is advisable in patients with perforated ulcers and no contraindications. In most cases, surgery can be successfully and effectively completed without conversion to laparotomy. Endoscopic closure of ulcerative defect is preferable since this procedure has certain advantages over traditional intervention, contributes to significant reduction in morbidity, mortality and hospital-stay.
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Úlcera Duodenal , Laparoscopía , Úlcera Péptica Perforada , Humanos , Úlcera Duodenal/complicaciones , Úlcera Duodenal/diagnóstico , Úlcera Duodenal/cirugía , Úlcera , Úlcera Péptica Perforada/diagnóstico , Úlcera Péptica Perforada/etiología , Úlcera Péptica Perforada/cirugía , Laparoscopía/efectos adversos , Laparoscopía/métodos , Laparotomía/efectos adversos , Resultado del Tratamiento , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/prevención & controlRESUMEN
We studied the effects of apoptotic bodies of cardiomyocytes (ApBc) and fibroblasts (ApBf) on myocardial regeneration and contractility in rats and the dynamics of RNA concentrations in cardiomyocytes and fibroblasts at different stages of apoptosis. ApBc increase the contractility of rat myocardium, while ApBf reduce it. ApBc stimulate the development of clones of cardiomyocyte precursors in the myocardium, while ApBf stimulate the formation of endothelial precursor clones. In doxorubicin cardiomyopathy, ApBc, similar to the reference drug (ACE inhibitor) improve animal survival, while ApBf produce no such effect. RNA concentrations in cardiomyocytes and fibroblasts before apoptosis and at the beginning of cell death significantly differed, while in apoptotic bodies of these cells, it was practically the same. It has been hypothesized that RNA complex present in ApBc and ApBf represents an "epigenetic code" of directed differentiation of cardiac stem cells.
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Envejecimiento/metabolismo , Cardiomiopatías/metabolismo , Medios de Cultivo/farmacología , Vesículas Extracelulares/metabolismo , Fibroblastos/metabolismo , Miocitos Cardíacos/metabolismo , Células Madre/metabolismo , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Animales , Apoptosis/efectos de los fármacos , Cardiomiopatías/inducido químicamente , Cardiomiopatías/tratamiento farmacológico , Cardiomiopatías/patología , Diferenciación Celular , Células Clonales , Medios de Cultivo/química , Doxorrubicina/toxicidad , Vesículas Extracelulares/química , Fibroblastos/citología , Fibroblastos/efectos de los fármacos , Fosinopril/farmacología , Masculino , Contracción Miocárdica/efectos de los fármacos , Miocardio/metabolismo , Miocardio/patología , Miocitos Cardíacos/citología , Miocitos Cardíacos/efectos de los fármacos , Cultivo Primario de Células , ARN/metabolismo , Ratas , Ratas Wistar , Transducción de Señal , Células Madre/citología , Células Madre/efectos de los fármacosRESUMEN
OBJECTIVE: The purpose of the study was to evaluate the influence of endoprosthetic repair of the aortic thoracic portion on remodelling of the descending aorta in patients after the surgical stage of correction for DeBakey type I aortic dissection. PATIENTS AND METHODS: The authors retrospectively analysed a group of 12 patients (9 men and 3 women) subjected to endoprosthetic repair of the aortic thoracic portion after previously performed surgical correction of the ascending aorta and its braches. The average age of the patients amounted to 48 (43-56.7) years. All patients underwent multispiral computed tomography (MSCT) first performed at admission, then immediately after implantation of the stent graft and at 6, 12 and 24 months after discharge. The Control Group consisted of nine patients with a previous history of DeBakey type I aortic dissection, who had endured only surgical correction of the ascending aorta and arch. RESULTS: The success rate of the intervention amounted to 100%. There were no signs of ischaemia of the spinal cord, visceral organs or lower limbs. The diameter of the implanted stent grafts varied from 28 to 40 mm and the length ranged from 140 to 204 mm. Seven (58%) patients of the Study Group as early as during a year were found to have no blood flow along the false channel. The false channel remained patent in 100% of the Control Group patients. Over a two-year period of follow up, in patients after endoprosthetic repair, the diameter of the false channel did not increase. In the Control Group patients during the same period of follow up, there was a tendency towards an increase in the aortic diameter at the expense of dilatation of the false channel, with an enlargement of the false channel of the descending aorta at the level of the diaphragm from 1.8 (1.57-2.1) to 2.05 (1.7-2.31) cm (p=0.4) and at the level of the renal arteries from 1.5 (1.32-1.8) to 1.8 (1.58-1.97) cm (p=0.4). There were no lethal outcomes during follow up. CONCLUSION: Endoprosthetic repair of the thoracic portion after surgical correction was in the remote period accompanied and followed by stabilization of the diameter of the descending aorta, as well as contributed to closure of the false channel.
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Aneurisma de la Aorta Torácica/cirugía , Disección Aórtica/cirugía , Implantación de Prótesis Vascular/efectos adversos , Procedimientos Endovasculares/métodos , Oclusión de Injerto Vascular , Stents , Adulto , Aorta Torácica/diagnóstico por imagen , Aorta Torácica/cirugía , Aortografía/métodos , Implantación de Prótesis Vascular/instrumentación , Implantación de Prótesis Vascular/métodos , Femenino , Oclusión de Injerto Vascular/diagnóstico , Oclusión de Injerto Vascular/fisiopatología , Oclusión de Injerto Vascular/cirugía , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/fisiopatología , Complicaciones Posoperatorias/cirugía , Reoperación/métodos , Estudios Retrospectivos , Federación de Rusia , Tomografía Computarizada por Rayos X/métodos , Resultado del Tratamiento , Remodelación VascularRESUMEN
Nanowire growth by the vapour-liquid-solid (VLS) process enables a high level of control over nanowire composition, diameter, growth direction, branching and kinking, periodic twinning, and crystal structure. The tremendous impact of VLS-grown nanowires is due to this structural versatility, generating applications ranging from solid-state lighting and single-photon sources to thermoelectric devices. Here, we show that the morphology of these nanostructures can be further tailored by using the liquid droplets that catalyse nanowire growth as a 'mixing bowl', in which growth materials are sequentially supplied to nucleate new phases. Growing within the liquid, these phases adopt the shape of faceted nanocrystals that are then incorporated into the nanowires by further growth. We demonstrate this concept by epitaxially incorporating metal-silicide nanocrystals into Si nanowires with defect-free interfaces, and discuss how this process can be generalized to create complex nanowire-based heterostructures.
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In situ transmission electron microscopy observations of nanowire morphologies indicate that during Au-catalyzed Ge nanowire growth, Ge facets can rapidly form along the nanowire sidewalls when the source gas (here, digermane) flux is decreased or the temperature is increased. This sidewall faceting is accompanied by continuous catalyst loss as Au diffuses from the droplet to the wire surface. We suggest that high digermane flux and low temperatures promote effective surface passivation of Ge nanowires with H or other digermane fragments inhibiting diffusion and attachment of Au and Ge on the sidewalls. These results illustrate the essential roles of the precursor gas and substrate temperature in maintaining nanowire sidewall passivation, necessary to ensure the growth of straight, untapered, ⟨111⟩-oriented nanowires.
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We demonstrate that argon ion bombardment of single crystal sapphire leads to the creation of substrates that support the growth of vertically aligned carbon nanotubes from iron catalysts with a density, height, and quality equivalent to those grown on conventional, disordered alumina supports. We quantify the evolution of the catalyst using a range of surface characterization techniques and demonstrate the ability to engineer and pattern the catalyst support through control of ion beam bombardment parameters.
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Drugs that block dopaminergic transmission are currently widely used in the treatment of psychiatric diseases. One of the significant, common complications of therapy are tardive dyskinesias, which develop after prolonged, at least 3 months, therapy with antipsychotics and significantly reduce the quality of life of patients. Tardive dyskinesia is an extrapyramidal disorder, mainly manifested by involuntary hyperkinesis of the muscles of the face and tongue. These movements negatively affect the patient's daily activities and quality of life. This article reviews the currently available treatment strategies for this type of disorder. One of the promising methods is therapy with Normokinesin (tetrabenazine), which, by reducing dopaminergic stimulation of brain neurons, significantly reduces hyperkinesis.
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Antipsicóticos , Discinesia Inducida por Medicamentos , Trastornos Mentales , Discinesia Tardía , Antipsicóticos/uso terapéutico , Discinesia Inducida por Medicamentos/tratamiento farmacológico , Discinesia Inducida por Medicamentos/etiología , Humanos , Trastornos Mentales/complicaciones , Calidad de Vida , Discinesia Tardía/inducido químicamente , Discinesia Tardía/complicaciones , Discinesia Tardía/tratamiento farmacológicoRESUMEN
The synucleinopathies are a group of neurodegenerative diseases characterized by the oligomerization of alpha-synuclein protein in neurons or glial cells. Recent studies provide data that ceramide metabolism impairment may play a role in the pathogenesis of synucleinopathies due to its influence on alpha-synuclein accumulation. The aim of the current study was to assess changes in activities of enzymes involved in ceramide metabolism in patients with different synucleinopathies (Parkinson's disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA)). The study enrolled 163 PD, 44 DLB, and 30 MSA patients as well as 159 controls. Glucocerebrosidase, alpha-galactosidase, acid sphingomyelinase enzyme activities, and concentrations of the corresponding substrates (hexosylsphingosine, globotriaosylsphingosine, lysosphingomyelin) were measured by liquid chromatography tandem-mass spectrometry in blood. Expression levels of GBA, GLA, and SMPD1 genes encoding glucoceresobridase, alpha-galactosidase, and acid sphingomyelinase enzymes, correspondently, were analyzed by real-time PCR with TaqMan assay in CD45 + blood cells. Increased hexosylsphingosine concentration was observed in DLB and MSA patients in comparison to PD and controls (p < 0.001) and it was associated with earlier age at onset (AAO) of DLB (p = 0.0008). SMPD1 expression was decreased in MSA compared to controls (p = 0.015). Acid sphingomyelinase activity was decreased in DLB, MSA patients compared to PD patients (p < 0.0001, p < 0.0001, respectively), and in MSA compared to controls (p < 0.0001). Lower acid sphingomyelinase activity was associated with earlier AAO of PD (p = 0.012). Our data support the role of lysosomal dysfunction in the pathogenesis of synucleinopathies, namely, the pronounced alterations of lysosomal activities involved in ceramide metabolism in patients with MSA and DLB.
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Enfermedad por Cuerpos de Lewy , Atrofia de Múltiples Sistemas , Enfermedad de Parkinson , Sinucleinopatías , Ceramidas , Humanos , Enfermedad por Cuerpos de Lewy/metabolismo , Atrofia de Múltiples Sistemas/patología , Enfermedad de Parkinson/patología , Esfingolípidos , Esfingomielina Fosfodiesterasa , alfa-Galactosidasa , alfa-Sinucleína/metabolismoRESUMEN
The near field underneath the ultrasonic probe fluid coupled to an isotropic solid is approximated in the frequency domain by a closed form asymptotic solution. The approximation is based on the problem decomposition and uses the stationary phase method evaluating the response to an equivalent surface source. This results in a sum of contributions, each dominating in a specific geometrical region, the main beam or a side lobe. The transitional zones are also described. The pulse trains are computed using the harmonic synthesis and compared with the results obtained by direct calculation of Fourier integrals. It is shown that the asymptotic approach permits us to elucidate the physics of problem and leads to a numerical algorithm which is about 10(4) times faster than the direct computations.
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Algoritmos , Modelos Teóricos , Transductores , Ultrasonido , Análisis de FourierRESUMEN
A two-compartment model of the dopaminergic neuron based on modified FitzHue-Nagumo oscillators for each compartment has been built. The compartments corresponded to the soma and dendrites and differed by the values of small parameters. The influence of stimuli (applied current for the somatic compartment and synaptic activation for the dendritic compartment) on the model has been studied. It has been shown that the activation of AMPA and NMDA synaptic currents lead to the generation of high-frequency bursts by the neuron. The mechanisms underlying the generation of the bursts have been investigated.
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Relojes Biológicos/fisiología , Dendritas/fisiología , Dopamina/metabolismo , Modelos Neurológicos , Sinapsis/fisiología , Animales , Humanos , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiónico/metabolismoRESUMEN
The relative organization of genes and repetitive DNAs in complex eukaryotic genomes is not well understood. Diagnostic sequencing indicated that a 280-kilobase region containing the maize Adh1-F and u22 genes is composed primarily of retrotransposons inserted within each other. Ten retroelement families were discovered, with reiteration frequencies ranging from 10 to 30,000 copies per haploid genome. These retrotransposons accounted for more than 60 percent of the Adh1-F region and at least 50 percent of the nuclear DNA of maize. These elements were largely intact and are dispersed throughout the gene-containing regions of the maize genome.
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Genoma de Planta , Retroelementos , Zea mays/genética , Cromosomas Artificiales de Levadura , ADN de Plantas/genética , Genes de Plantas , Datos de Secuencia Molecular , Secuencias Repetitivas de Ácidos NucleicosRESUMEN
Synchronization processes have been studied within the framework of a model describing the dynamics of two inferior olive cells coupled electrotonically through gap junctions surrounded by synaptic inhibitory terminals that block these couplings. A simple model of a chemical synaptic terminal based on the first-order kinetics has been constructed to describe the coupling break. It was found that different types of synchronous behavior exist in the system, depending on the parameters. These are 1:1 and 1:2 synchronization regimes, spike time binding, and others. It was demonstrated that even small changes in the coupling parameters (coupling strength and coupling break delay) may significantly affect the synchronous regimes of interacting cells. In some cases, the activity of one of inferior olive cells is suppressed due to collective dynamics, whereas the activity of the other cell is conserved.
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Sinapsis Eléctricas/fisiología , Uniones Comunicantes/fisiología , Modelos Neurológicos , Neuronas/fisiología , Animales , HumanosRESUMEN
We analyzed a generic relaxation oscillator under moderately strong forcing at a frequency much greater that the natural intrinsic frequency of the oscillator. Additionally, the forcing is of the same sign and, thus, has a nonzero average, matching neuroscience applications. We found that, first, the transition to high-frequency synchronous oscillations occurs mostly through periodic solutions with virtually no chaotic regimes present. Second, the amplitude of the high-frequency oscillations is large, suggesting an important role for these oscillations in applications. Third, the 1:1 synchronized solution may lose stability, and, contrary to other cases, this occurs at smaller, but not at higher frequency differences between intrinsic and forcing oscillations. We analytically built a map that gives an explanation of these properties. Thus, we found a way to substantially "overclock" the oscillator with only a moderately strong external force. Interestingly, in application to neuroscience, both excitatory and inhibitory inputs can force the high-frequency oscillations.
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Despite nearly 30 years of experience in the application of botulinum toxin type A (BTA) in clinical practice, many fundamental questions of therapy remain valid. There are 5 botulinum toxin type A used for neurological indications in the Russian Federation in 2017. They contain different number of active neuroprotein (150 kDa) in a therapeutic dose of the drug that may have a potential impact on the efficacy and duration of action. The current SmPC of each BTA stated that the unit of activity is unique and can not be compared with any other BTA. In scientific publications one can find many details concerning the equivalence doses of onabotulinumtoxin A (botox) and abobotulinumtoxin A (dysport) and the ratio of units varies from 1:1 to 1:11. However, according to clinical guidelines, systematic reviews and high quality research evidence of recent years, the ratio of units of abobotulinumtoxin A (dysport) and onabotulinumtoxin A (botox) is 3(2,5):1. Use of a fixed ratio of units is possible only when switching from one drug to another or in case of limiting access to specific drug. Botulinum toxin type A is the first line of therapy in the treatment of several neurological diseases. The most commonly used drugs of botulinum toxin type A (botox, dysport, xeomin) have a significant evidence base that confirms their efficacy and optimal safety profile. The main difference between botulinum toxin type A is their potential activity of action, i.e., activity units and total therapeutic dose.