Molecular mechanisms of vascular tissue patterning in Arabidopsis thaliana L. roots.

A vascular system in plants is a product of aromorphosis that enabled them to colonize land because it delivers water, mineral and organic compounds to plant organs and provides effective communications between organs and mechanical support. Vascular system development is a common object of fundamental research in plant development biology. In the model plant Arabidopsis thaliana, early stages of vascular tissue formation in the root are a bright example of the self-organization of a bisymmetric (having two planes of symmetry) pattern of hormone distribution, which determines vascular cell fates. In the root, vascular tissue development comprises four stages: (1) specification of progenitor cells for the provascular meristem in early embryonic stages, (2) the growth and patterning of the embryo provascular meristem, (3) postembryonic maintenance of the cell identity in the vascular tissue initials within the root apical meristem, and (4) differentiation of their descendants. Although the anatomical details of A. thaliana root vasculature development have long been known and described in detail, our knowledge of the underlying molecular and genetic mechanisms remains limited. In recent years, several important advances have been made, shedding light on the regulation of the earliest events in provascular cells specification. In this review, we summarize the latest data on the molecular and genetic mechanisms of vascular tissue patterning in A. thaliana root. The first part of the review describes the root vasculature ontogeny, and the second reconstructs the sequence of regulatory events that underlie this histogenesis and determine the development of the progenitors of the vascular initials in the embryo and organization of vascular initials in the seedling root.

Superconductivity in an extreme strange metal.

Some of the highest-transition-temperature superconductors across various materials classes exhibit linear-in-temperature 'strange metal' or 'Planckian' electrical resistivities in their normal state. It is thus believed by many that this behavior holds the key to unlock the secrets of high-temperature superconductivity. However, these materials typically display complex phase diagrams governed by various competing energy scales, making an unambiguous identification of the physics at play difficult. Here we use electrical resistivity measurements into the micro-Kelvin regime to discover superconductivity condensing out of an extreme strange metal state-with linear resistivity over 3.5 orders of magnitude in temperature. We propose that the Cooper pairing is mediated by the modes associated with a recently evidenced dynamical charge localization-delocalization transition, a mechanism that may well be pertinent also in other strange metal superconductors.

[Theory and practice of aging upon COVID-19 pandemic.]

Never before in history, aging was such a significant factor for epidemics as it is now for the current COVID-19 pandemic, which features a drastic shift of mortality towards older ages. Our analysis of data on COVID-19-related mortality in Spain, Italy, and Sweden has shown that, in the range of 30 to 90 years of age, each dependency of the logarithm of mortality upon age is linear, and all regression lines are strictly parallel to those related to the total mortality in accordance with the Gompertz law. In all cases, irrespective of the stage and place of epidemic, mortality doubling time in this age range is close to 7,5 years. The rates of being infected with the SARS-CoV-2 coronavirus and of being diagnosed due to the symptomatic manifestations of the infection are dependent on age to a far lesser degree. With account for these observations, three messages are put forth: 1) Older persons are the principal victims of both SARS-CoV-2 and measures undertaken to control its spread; 2) Older persons are not the principal driving force of SARS-CoV-2 spread; 3) Older persons can and should be engaged in combating the pandemic and its consequences; however, not via selective social distancing and other discriminative measures. People aged over 65 years constitute a significant part of the current population. They have specific interests and needs, which deserve no less respect than those of any other age group. This includes the right for the quality of life that remains sustained under the emergency conditions. Since the prospects for controlling the SARS-CoV-2 are dubious, those in charge of decisions concerning «people aged above 65¼ should mind that currently, unlike in the medieval ages, 65+ is the individual future of almost everyone.

Adsorptive therapy as a modificator for tumor-host interaction.

The potential of one of the adsorption methods, enterosorption (ES), using the new generation of carbon adsorbents to correct the negative manifestations of tumor-host interaction in the framework of paraneoplastic syndrome (PNS) as well as systemic toxicity of chemo- and radiation therapy, is discussed. The ES influence on the development of PNS was demonstrated in C57/BL6 mice with transplanted Lewis lung carcinoma. Two-week administration of carbon enterosorbents resulted in a significant suppression of metastasis and correction of tumor-related anemia, activation of granulocytic line in the bone marrow with nearly 3-fold enhancement of its mitotic activity. ES exerted a positive influence on the structural-morphologic indexes and regenerative potential of kidneys and liver, mitigated manifestations of oxidative stress, decreased the level of endogenous intoxication, increased resistance of erythrocyte membranes and decreased ligand loading of blood plasma transport proteins. The effect of ES on anticancer activity and toxic reactions of cisplatin (CP) was evaluated in Guerin carcinoma-bearing rats. ES reduced significantly creatinine and other kidney biochemical indexes elevated in the blood plasma of rats after CP treatment. ES attenuated dystrophic changes in the histological structure of internal organs (kidney, liver, spleen), caused by tumor growth and significantly aggravated under the influence of CP. Such changes were specially traced in the kidneys and well reflect the nephroprotective potential of ES. In rats irradiated with X-ray in sublethal dose, highly activated granulated carbonic enterosorbents facilitated the restoration of white blood cells and lymphocyte count. The results obtained confirm the insights of academician R.E. Kavetsky predicting the future of adsorptive detoxification with activated carbons in the treatment of cancer patients.

Estimation of Decellularization and Recellularization Quality of Tissue-Engineered Constructions by the Chemiluminescence Method.

It was found that the chemiluminescence intensity in native and recellularized tissues of rat muscular organs as well as in their decellularized scaffolds can serve as an express criterion that, along with ultrastructural analysis, makes it possible to perform quantitative assessment of the viability of cellular structures in biological samples of the diaphragm.

[Hybrid intervention for a ruptured thoracoabdominal aortic aneurysm]. / Gibridnoe vmeshatel'stvo pri razryve torakoabdominal'noi anevrizmy aorty.

A ruptured thoracoabdominal aortic aneurysm is an urgent situation requiring emergency surgery during which it is necessary to decrease the scope of the intervention in a patient at an extremely high surgical risk. A combination of surgical and endovascular techniques makes it possible to minimize surgical injury, blood loss, to shorten the duration of internal organs ischaemia, to reduce the risk of paraplegia. Presented herein are the results of emergency hybrid intervention for a ruptured thoracoabdominal aortic aneurysm, accompanied and followed by description of the technical aspects of performing the surgical and endovascular stages. The early postoperative period was complicated by thrombosis of the left superficial femoral artery on the background of atherosclerotic lesions, which was successfully eliminated by means of endovascular intervention with endovascular prosthetic repair. After 10 months, the patient underwent a cardiosurgical intervention. Combining surgical and endovascular techniques made it possible in an emergency situation to save the patient's life and to provide its good quality in the remote period of follow up (4 years after the hybrid operation).

Enzymatic synthesis of cefazolin using immobilized recombinant cephalosporin-acid synthetase as the biocatalyst.

A method for the synthesis of ß-lactam antibiotic cefazolin (CEZ) by enzymatic acylation of 7-amino-3-(5-methyl-l,3,4-thiadiazol-2-yl)thiomethyl-3-cephem-4-carboxylic acid (TDA) using immobilized cephalosporin-acid synthetase (IECASA) from recombinant E. coli strain VKPM B-12316 has been developed. A stepwise pH gradient designed on the basis of investigations on the solubility of components was applied for synthesis. This helped in avoiding the precipitation of TDA in the reaction when its initial concentration was high (150-200 mM). Thus, under optimal conditions a high yield of CEZ (relative to TDA) of 92-95% was obtained. Where the final reaction mixture contained 65-85 mg/mL of CEZ, 4-5 mg/mL of unreacted TDA, and 40-60 mg/mL of the by-product, 1(H)-tetrazolylacetic acid (TzAA). Testing of optimized CEZ synthesis using IECASA in a batch reactor has proved sufficiently high operational stability of the biocatalyst, with its residual activity after the 25th cycle accounting for about 83 ± 2% of its starting value. The half-inactivation period of IECASA was estimated as 85 cycles of CEZ synthesis.

Highly activated carbon enterosorbent mediates the suppression of paraneoplastic syndrome associated with Lewis lung carcinoma in mice.

AIM: To investigate the effect of enterosorption on the development of paraneoplastic syndrome in mice with Lewis lung carcinoma (LLC). MATERIALS AND METHODS: The study was performed on male С57/ВL6 mice with transplanted LLC. As an enterosorbent, highly activated powder fraction of HSGD was administered per os daily at a dose of 0.625 g/kg for two weeks starting from the 7th day after tumor cell transplantation. Analysis of hemo- and myelograms, morphological alterations in vital organs, the activities of catalase and superoxide dismutase, biochemical analysis of blood and quantitative analysis of hydroperoxides, malonic dialdehyde, аdvanced oxidation protein products was carried out by standard methods after completing the course of enterosorption. Ligand loading of blood plasma proteins was estimated by the method of differential scanning microcalorimetry. RESULTS: Administration of enterosorbent resulted in inhibition of LLC growth and in nearly 2-fold decrease of lung metastases number (p < 0.05). Activation of granulocytic line in the bone marrow with nearly 3-fold enhancement of mitotic activity took place after enterosorbent administration. Red cell lineage indices and bone marrow cellularity remained unaltered. After enterosorption session, the studied biochemical indices of peripheral blood evidenced on decreasing the endogenous intoxication and oxidative stress levels, improving the functional state of kidneys, increasing the resistance of erythrocyte membranes and lowering the ligand loading of blood plasma transport proteins. Morphological structure of kidneys and liver confirmed significant positive effect of enterosorption. The data of morphologic examination of gastric fundus, small intestine, and large bowel slides after 2-week administration of enterosorbent showed its high safety and proper evacuation from intestine. CONCLUSION: The two-week long enterosorption session in mice with LLC caused the suppression of tumor growth and metastasis, normalization of bone marrow hemopoiesis. Enterosorption exerted a positive influence on the structural-morphologic indexes and regenerative potential of kidneys and liver, mitigated manifestations of oxidative stress, decreased the level of endogenous intoxication, promoted deliganding of albumin molecule and deloading of erythrocyte membranes.

[Hybrid intervention for a multilevel aneurysmatic lesion of the aorta in a patient with multifocal atherosclerosis]. / Gibridnoe vmeshatel'stvo pri mnogourovnevom anevrizmaticheskom porazhenii aorty u bol'nogo s mul'tifokal'nym aterosklerozom.

A multilevel aneurysmatic lesion of the aorta is a rare pathology. The authors describe herein a clinical case report regarding stage-wise treatment of a patient presenting with aneurysms of the thoracic and abdominal portions of the aorta and a haemodynamically significant lesion of coronary and carotid arteries. Strategy of surgical management was decided upon collegially. Successful endoprosthetic repair of the aneurysm of the thoracic portion of the aorta required closure of the left carotid artery with a graft, which, taking into consideration an existing occlusion of the right internal carotid artery, demanded preliminary carotid-subclavian bypass grafting. The clinical course of progressing angina pectoris (75% stenosis of the anterior descending artery with a poststenotic aneurysm) also increased the risk of the surgical stage. The authors provide a detailed description of the planning procedure, stages, and technical aspects of the operations performed. No complications were encountered. The duration of the follow up period amounted to 15 months. There was regression of the symptomatic manifestations, accompanied and followed by complete thrombosis of the aneurysmatic zones stented. A hybrid approach demonstrated efficacy and safety in staged treatment of complicated combined pathology of the aorta and its branches.

[POPULATION AGING IN KAZAKHSTAN. 1. PROBLEMS AND OPPORTUNITIES].

This review article is devoted to the distinctive aspects of population aging in the Republic of Kazakhstan. The demographic parameters of aging are analyzed, as well as their implications for various spheres of Kazakhstan society, such as health care, social security and social services.

Kondo Insulator to Semimetal Transformation Tuned by Spin-Orbit Coupling.

Recent theoretical studies of topologically nontrivial electronic states in Kondo insulators have pointed to the importance of spin-orbit coupling (SOC) for stabilizing these states. However, systematic experimental studies that tune the SOC parameter λ_{SOC} in Kondo insulators remain elusive. The main reason is that variations of (chemical) pressure or doping strongly influence the Kondo coupling J_{K} and the chemical potential µ-both essential parameters determining the ground state of the material-and thus possible λ_{SOC} tuning effects have remained unnoticed. Here, we present the successful growth of the substitution series Ce_{3}Bi_{4}(Pt_{1-x}Pd_{x})_{3} (0≤x≤1) of the archetypal (noncentrosymmetric) Kondo insulator Ce_{3}Bi_{4}Pt_{3}. The Pt-Pd substitution is isostructural, isoelectronic, and isosize, and it therefore is likely to leave J_{K} and µ essentially unchanged. By contrast, the large mass difference between the 5d element Pt and the 4d element Pd leads to a large difference in λ_{SOC}, which thus is the dominating tuning parameter in the series. Surprisingly, with increasing x (decreasing λ_{SOC}), we observe a Kondo insulator to semimetal transition, demonstrating an unprecedented drastic influence of the SOC. The fully substituted end compound Ce_{3}Bi_{4}Pd_{3} shows thermodynamic signatures of a recently predicted Weyl-Kondo semimetal.

[Population aging in Kazakhstan. 2. Public policy responses.]

This article consists of the concluding sections of the review devoted to the issues of population aging in the Republic of Kazakhstan. The presented material is intended to substantiate strategic approaches for addressing the evolving process of population aging in Kazakhstan.

[Recombinant cephalosporin-acid synthesase: optimisation of expression in E.coli cells, immobilisation and application for biocatalytic cefazolin synthesis].

Cephalosporin acid synthetase (CASA) is responsible for specific to synthesis of cephalosporin-acids, its expression in Escherichia coli cells is accompanied by accumulation of unprocessed insoluble precursor. In order to optimize conditions of recombinant CASA production we have studied the effects of several parameters of strain cultivation, including growth media composition, temperature, and inoculation dose. Also plasmids for production of CASA variants with the signal sequence of Erwinia carotovora L-asparaginase (ansCASA) and "leaderless" CASA were created in search of more efficient expression constructs. Removal of the N-terminal secretion signal sequence reduced the production of functionally active CASA more than 10-fold and inhibited strain growth. Insertion of the L-asparaginase signal sequence increased the specific enzyme activity in the resultant recombinant strain. The ansCASA producing strain was used to develop the method of immobilization of the recombinant enzyme on an epoxy-activated macroporous acrylic support. The resultant biocatalyst performed effective synthesis of cefazolin from 3-[(5-methyl-1,3,4-thiadiazol-2-il)-thiomethyl]-7- aminocephalosporanic acid (MMTD-7-ACA) and methyl ester of 1(H)-tetrazolilacetic acid (МETzAA), under mild conditions a transformation level of MMTD-7-ACA to cefazolin of 95% is reached.

[The Rheological Properties of Blood Depending on Age and Sex].

The rheological properties of blood (viscosity, concentration of red blood cells, erythrocyte sedimantation rate, prothrombin index, and fibrinogen and blood lipid concentration) were studied in apparently healthy subjects of both sexes within the age range from 1 to 75 years. We observed an increase in blood viscosity from infancy to adulthood, followed by a decrease in older age in males. A progressive increase in viscosity is observed in females with aging. We determined three age periods during which the viscosity values remain constant: 1) from the period of early infancy to the second childhood (3.6 ± 0.07 mPa s regardless of sex); 2) from adolescence to the second period of adulthood (5.1 ± 0.06 in men; 4.3 ± 0.05 mPa s in women); 3) elderly and senile age (4.7 ± 0.13 in men; 4.4 ± 0.09 mPa s in women). Sex-related differences in the absolute value of blood viscosity (p < 0.001) were discovered in the period of adulthood. Moreover, we observed sex-related differences in the values of determination coefficients of interrelation between viscosity and the level of red blood cells (R(M)2 = 0.41, p < 0.001; R(F)2 = 0.35, p < 0.001), and viscosity and cholesterol level (R(M)2 = 0.47, p < 0.001; R(F)2 = 0.68, p < 0.001) among men and women. The factor analysis showed that blood viscosity correlates with the concentration of red blood cells by 28%; with the level of fibrinogen, by 23%; with the cholesterol concentration, by 20%.

Thermal, magnetic and electronic properties of non-centrosymmetric YbPt2B.

Ternary YbPt2B crystallizes in the non-centrosymmetric hexagonal CePt2B-type structure (space group P6(2)22). Electrical resistivity, specific heat and magnetic measurements reveal a magnetic instability at 5.6 K. Furthermore, a spin-reorientation of presumably a ferromagnetic type occurs around 1.5 K. The behaviour at low temperature is governed by a rather weak Kondo effect, T(K) ⩽ 1 K, in the presence of strong crystalline electric field splitting, with a doublet ground state. Besides, the complex magnetic behaviour presumably results from a Dzyaloshinskii-Moriya interaction triggered by the absence of inversion symmetry in the crystal structure. Scaling according to the de Gennes factor traces back magnetic ordering in YbPt2B to the Rudermann-Kittel-Kasuya-Yoshida (RKKY) interaction and the smooth evolution of the lattice constants and the unit cell volume of REPt2B (RE = rare earths) refers to the 4f(13) electronic configuration of Yb in YbPt2B.

[International cooperation on aging: areas and players].

This review article is devoted to the issues of international cooperation on ageing. It aims at describing the basic areas of cooperation and introducing its major players. Within the limited length of a journal article it is hardly possible to offer an exhaustive presentation of all available information; thus the article strives to provide a general orientation within the selected themes. The authors are hopeful that the presented materials will be of interest to the policy oriented researchers, policy makers and professionals working in the field of ageing and related areas such as social security, health and social services etc., as well as to the activists of non-governmental organizations.

The influence of enterosorption on some haematological and biochemical indices of the normal rats after single injection of melphalan.

AIM: One of the most prominent side effects of intensive cancer chemotherapy is bone marrow suppression which is an independent negative prognostic factor for the time to tumor progression. The aim of the study was to evaluate the myeloprotective possibilities of carbon enterosorbents in the case of usage of alkilating drug melphalan (L-PAM). MATERIALS AND METHODS: L-PAM was injected intravenously to healthy inbred rats to cause the myelosuppression. 3 days before and 7 days after this, suspension of two types of carbon granulated enterosorbents were administered per os one time per day. On 8(th) day after L-PAM injection, the rats were weighted and blood and liver tissue were taken under Ketamine general anesthesia for biochemical examination. Peripheral blood smears were made also. RESULTS: Melphalan at a dose of 3 mg/kg causes expressed myelotoxic reaction: leucopenia, decreasing of erythrocytes, hemoglobin and platelets counts. Even on 8(th) day after single injection of this cytostatic we can detect expressed signs of oxidative stress like increasing of hydroperoxides, TBA-reactive substances, and decreasing of activity and level of main endogenic antioxidants - superoxide dismutase (SOD), catalase and reduced glutathione. L-PAM causes also the violation of kidney function such as increase of urea and creatinine level; and rising of endogenic intoxication with elevation of middle mass molecules level. In a dose of 3 mg/kg melphalan has no negative influence on liver function on 8(th) day of experiment. Enterosorption with carbon enterosorbents C1 (bulk density γ = 0.28 g/cm(3), granules diameter 0.15-0.25 mm, BET pore surface 1719 m(2)/g, therapeutic dosage 1400 mg/kg) and C2 (bulk density γ = 0.18 g/cm(3), granules diameter 0.15-0.25 mm, BET pore surface 2162 m(2)/g, therapeutic dosage 900 mg/kg) diminishes and mitigates negative side effects caused by single intravenous injection of melphalan. Carbon enterosorbent C2 have rather more expressed positive effect than C1 for practically all indices. The most important curative effect due to C2 administration is prominent myeloprotection of bone marrow of experimental animals. CONCLUSION: Carbon enterosorbent C2 is promising and perspective sorbent for prophylaxis and treatment of side effects of cytostatic chemotherapy including myelotoxicity, mucositis, kidney injuries, gonadotoxicity, etc.

Band filling effect on polaron localization in La1-x(Ca(y)Sr1-y)xMnO3 manganites.

We report on a ìSR and 55 Mn NMR investigation of the magnetic order parameter as a function of temperature in the optimally doped La(5/8)(CaySr(1.y))(3/8)MnO3 and in the underdoped La1.xSrxMnO3 and La1.xCaxMnO3 metallic manganite families. The study is aimed at unravelling the effect of lattice distortions, implicitly controlled by the Ca-Sr isoelectronic substitution, from that of hole doping x on the Curie temperature TC and the order of the magnetic transition. At optimal doping, the transitions are second order at all y values, including the y = 1 (La(5/8)Ca(3/8)MnO3) end member. By contrast, they are first order in the underdoped samples, which show a finite (truncated) order parameter at the Curie point, including La(0.75)Sr(0.25)MnO3 whose TC is much higher than that of La(5/8)Ca(3/8)MnO3. The order parameter curves, on the other hand, exhibit a very minor dependence on x, if truncation is excepted. This suggests that the effective exchange interaction between Mn ions is essentially governed by local distortions, in agreement with the original double-exchange model, while truncation is primarily, if not entirely, an effect of under- or over-doping. A phase diagram, separating in the x.y plane polaron-driven first order transitions from regular second order transitions governed by critical fluctuations, is proposed for the La(1.x)(CaySr(1.y))xMnO3 system.

[The study of hemodynamic parameters of human internal carotid arteries depending on the age considering the sex and the localization of the artery].

The research of the ultrasound diameter, linear velocity and the resistance of internal carotid arteries of 647 people of both sexes aged from one to 74 years was conducted. Additionally, shear stress and the Reynolds number were calculated. During the period from early childhood to adolescence and from the first mature to old age there is an increase in the diameter of the internal carotid arteries. The phases of increased vascular resistance by the first period of childhood, adolescence and old age are observed. Volumetric flow rate has relatively stable parameters till adolescence, then it declines by old age. The average linear velocity, shear stress, and the Reynolds number diminish progressively twice with age. Laminar blood flow with local twists in the early stages of postnatal ontogenesis is characteristic of internal carotid arteries. The diameter of internal carotid arteries, vascular resistance index, blood flow velocity are higher in males than in females during most age periods. Shear stress in both internal carotid arteries during the age periods studied is symmetrical and has no sex differences.