Journal articles: 'Complexos de rodi'

1

Paris, Sophie, Jean-Paul Debeaupuis, Reto Crameri, Marilyn Carey, Franck Charlès, Marie Christine Prévost, Christine Schmitt, Bruno Philippe, and Jean Paul Latgé. "Conidial Hydrophobins of Aspergillus fumigatus." Applied and Environmental Microbiology 69, no. 3 (March 2003): 1581–88. http://dx.doi.org/10.1128/aem.69.3.1581-1588.2003.

Full text

Abstract:

ABSTRACT The surface of Aspergillus fumigatus conidia, the first structure recognized by the host immune system, is covered by rodlets. We report that this outer cell wall layer contains two hydrophobins, RodAp and RodBp, which are found as highly insoluble complexes. The RODA gene was previously characterized, and ΔrodA conidia do not display a rodlet layer (N. Thau, M. Monod, B. Crestani, C. Rolland, G. Tronchin, J. P. Latgé, and S. Paris, Infect. Immun. 62:4380-4388, 1994). The RODB gene was cloned and disrupted. RodBp was highly homologous to RodAp and different from DewAp of A. nidulans. ΔrodB conidia had a rodlet layer similar to that of the wild-type conidia. Therefore, unlike RodAp, RodBp is not required for rodlet formation. The surface of ΔrodA conidia is granular; in contrast, an amorphous layer is present at the surface of the conidia of the ΔrodA ΔrodB double mutant. These data show that RodBp plays a role in the structure of the conidial cell wall. Moreover, rodletless mutants are more sensitive to killing by alveolar macrophages, suggesting that RodAp or the rodlet structure is involved in the resistance to host cells.

APA, Harvard, Vancouver, ISO, and other styles

2

Figueira, João, Wojciech Czardybon, José Carlos Mesquita, João Rodrigues, Fernando Lahoz, Luca Russo, Arto Valkonen, and Kari Rissanen. "Synthesis, characterization and solid-state photoluminescence studies of six alkoxy phenylene ethynylene dinuclear palladium(ii) rods." Dalton Transactions 44, no. 9 (2015): 4003–15. http://dx.doi.org/10.1039/c4dt00493k.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Sandroni, Carlos. "Samba de roda, patrimônio imaterial da humanidade." Estudos Avançados 24, no. 69 (2010): 373–88. http://dx.doi.org/10.1590/s0103-40142010000200023.

Full text

Abstract:

Em 2005, o samba de roda, forma musical-coreográfica da região do Recôncavo, na Bahia, foi incluída pela Unesco na sua III Declaração de Obras-Primas do Patrimônio Imaterial da Humanidade. Essa candidatura vitoriosa foi construída num processo complexo, que envolveu agentes de políticas públicas, antropólogos, etnomusicólogos e, especialmente, sambadores e sambadoras do Recôncavo. A candidatura envolveu a elaboração de um Plano de Ação, previsto para cinco anos, para a salvaguarda do samba de roda no Recôncavo. No presente texto, depois de tratar brevemente do processo que levou à premiação da Unesco, são abordadas sobretudo questões suscitadas pela implementação do Plano de Ação, que se estruturou em torno de quatro "eixos": organização dos sambadores do Recôncavo, transmissão, difusão e documentação do samba de roda.

APA, Harvard, Vancouver, ISO, and other styles

4

Bowers, Philip L. "The upper Perron method for labelled complexes with applications to circle packings." Mathematical Proceedings of the Cambridge Philosophical Society 114, no. 2 (September 1993): 321–45. http://dx.doi.org/10.1017/s0305004100071619.

Full text

Abstract:

The construction of geometric surfaces via labelled complexes was introduced by Thurston[16, chapter 13], and subsequent applications and developments have appeared in [1, 3, 4, 5, 14, 15]. The basic idea of using labelled complexes to produce geometric structures is that the vertices of a simplicial triangulation of a surface can be labelled with positive real numbers that collectively determine a metric of constant curvature ±1 or 0, with possible singularities at vertices, by using the label values to identify 2-simplices of the triangulation with geometric triangles. Beardon and Stephenson[1] developed a particularly simple method for producing non-singular surfaces via labelled complexes that is modelled after the classical Perron method for producing harmonic functions, and they applied their method in [2] to construct a fairly comprehensive theory of circle packings in general Riemann surfaces. This Perron method was developed more fully by Stephenson and the author in [3, 4] and applied to the study of circle packing points in moduli space. At about the same time and independently of Beardon, Stephenson, and Bowers, Carter and Rodin [5] and Doyle [8] developed the method for flat surfaces and Minda and Rodin [14] developed the method for finite type surfaces. Minda and Rodin [14] applied their development to give partial solutions to the labelled complex version of the classical Schwarz-Picard problem that concerns the construction of singular hyperbolic metrics on surfaces with prescribed singularities. In this paper, we modify the aforementioned approaches and examine the upper Perron method for producing non-singular geometric surfaces. This upper method has several advantages over the Perron method as developed previously and provides a complete solution to the labelled complex version of the Schwarz-Picard problem.

APA, Harvard, Vancouver, ISO, and other styles

5

Rees-Isele, Luitgard, Hans-Peter Winkler, and Egbert Keller. "In Search of the True Structure of the Sodium Chromium Alum II: Crystal Growth and Structure of the Double Salt NaCr(SO4)2(H2O)6·(CH3OH)0.6(2)· (H2O)1.5(5)." Zeitschrift für Naturforschung B 68, no. 12 (December 1, 2013): 1288–94. http://dx.doi.org/10.5560/znb.2013-3200.

Full text

Abstract:

Attempts to crystallize the sodium chromium alum, NaCr(SO4)2(H2O)12, from water=methanol solutions at temperatures around 281 K yielded crystals of the title compound instead. Their monoclinic structure can be described as a centered rectangular array of linear {1∞}[Na(SO4)2]3- rods aligned parallel to [001] with vicinal rods held together by columns of isolated [Cr(H2O)6]3+ complexes. The structure forms channels parallel to [001] which are occupied by methanol and water molecules with atomic site occupancy factors of 1/5 and less. Various attempts to crystallize the compound or the sodium chromium alum from purely aqueous solutions remained unsuccessful

APA, Harvard, Vancouver, ISO, and other styles

6

Triantis, Charalampos, Antonio Shegani, Christos Kiritsis, Catherine Raptopoulou, Vassilis Psycharis, Maria Pelecanou, Ioannis Pirmettis, and Minas Papadopoulos. "Crystal structure offac-tricarbonyl(cyclohexyl isocyanide-κC)(quinoline-2-carboxylato-κ2N,O)rhenium(I)." Acta Crystallographica Section E Crystallographic Communications 72, no. 3 (February 17, 2016): 358–62. http://dx.doi.org/10.1107/s2056989016002206.

Full text

Abstract:

In the title compound, [Re(C10H6NO2)(C7H11N)(CO)3], the ReIatom is coordinated by three carbonyl ligands in a facial arrangement and by the N, O and C atoms from a chelating quinaldate anion and a monodentate isocyanide ligand, respectively. The resultant C4NO coordination sphere is distorted octahedral. A lengthening of the axial Re—CO bondtransto the isocyanide ligand is indicative of thetranseffect. Individual complexes are stacked into rods parallel to [001] through displaced π–π interactions. Weak C—H...O hydrogen-bonding interactions between the rods lead to the formation of layers parallel to (010). These layers are stacked along [010] by C—H...H—C van der Waals contacts.

APA, Harvard, Vancouver, ISO, and other styles

7

Koshel, Sergiy, and Ganna Koshel. "Analysis of fourth-grade flat machines with movable close-cycle formed by the rods and two complex links." Odes’kyi Politechnichnyi Universytet. Pratsi, no. 2 (August 20, 2016): 5–10. http://dx.doi.org/10.15276/opu.2.49.2016.03.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Bazunova, Marina V., Robert A. Mustakimov, Nadezhda V. Dmitrieva, Diana R. Dayanova, and Andrey A. Bazunov. "Study of the physical and chemical properties of materials based on polymer complexes of some water-soluble polymers." Butlerov Communications 62, no. 5 (May 31, 2020): 91–96. http://dx.doi.org/10.37952/roi-jbc-01/20-62-5-91.

Full text

Abstract:

Polymer complexes based on water-soluble physiologically-neutral polymers are promising for creating biomedical materials used in targeted delivery systems of drugs, enzymes or genes, as well as for encapsulating biological substances in biomedicine. In this work, the creation of film materials based on polymer complexes has used the sodium salt of succinyl chitosan, polyvinylpyrrolidone, sodium salt of carboxymethylcellulose, polyethylene glycol. Polyvinylpyrrolidone and polyethylene glycol are characterized by unsatisfactory a film-forming and gel-forming property, which limits their application in medical practice. These shortcomings have been compensated by the introduction of polysaccharides. It has been shown that the variation in composition of the studied polymer complexes allows changing purposefully the hydrophilic-hydrophobic balance of the surface and sorption properties of polymer films based on them. The preparation of polymer complexes consisted of adding a portion of poly-N-vinylpyrrolidone or polyethylene glycol to solutions of the sodium salt of succinyl chitosan or sodium salt of carboxymethylcellulose so that the ratio of the components of the complex was equimolar. Films based on polymer complexes were prepared by the method of pouring solutions of polymer mixtures with a concentration of 1 mol/L onto a previously defatted surface of a Petri dish. The thickness of the film samples was maintained constant and equal to 0.1 mm. It was shown that the preparation of polymer complexes of the sodium salt of chitosan succinyl or the sodium salt of carboxymethyl cellulose with poly-(N-vinylpyrrolidone) or polyethylene glycol allows one to purposefully change the hydrophilic-hydrophobic balance of the surface of polymer films based on them. Also, film materials based on the studied polymer complexes have satisfactory sorption properties for water vapor. These facts suggest that systems based on polymer complexes of the sodium salt of chitosan succinyl or sodium salt of carboxymethylcellulose with poly (N-vinyl pyrrolidone) or polyethylene glycol can serve as the basis for the creation of film or gel polymer materials for medical use.

APA, Harvard, Vancouver, ISO, and other styles

9

DeRouchey, Jason, Greg F. Walker, Ernst Wagner, and Joachim O. Rädler. "Decorated Rods: A “Bottom-Up” Self-Assembly of Monomolecular DNA Complexes." Journal of Physical Chemistry B 110, no. 10 (March 2006): 4548–54. http://dx.doi.org/10.1021/jp053760a.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Kedzierski, W., W. N. Moghrabi, A. C. Allen, M. M. Jablonski-Stiemke, S. M. Azarian, D. Bok, and G. H. Travis. "Three homologs of rds/peripherin in Xenopus laevis photoreceptors that exhibit covalent and non-covalent interactions." Journal of Cell Science 109, no. 10 (October 1, 1996): 2551–60. http://dx.doi.org/10.1242/jcs.109.10.2551.

Full text

Abstract:

We have isolated and characterized three homologs of mammalian rds/peripherin from Xenopus retinae. One (xrds38) is likely the Xenopus ortholog, while the other two (xrds36 and -35) are more distant relatives. By immunocytochemical analysis of retinal sections, xrds38 is distributed in both rod and cone photoreceptors, while xrds36 and xrds35 are present in rods only. At the EM level, xrds38 is present specifically in the rims and incisures of rod and cone outer segment discs. All are N-glycosylated and form covalent dimers. Immunoprecipitation analysis showed that in rods, these three proteins interact to form heterotetrameric or higher-order complexes. The pattern of sequence conservation among the xrds proteins, mammalian rds/peripherin, and mammalian rom-1 suggest that the central portion of the intradiscal D2 loop contains the interacting structural elements.

APA, Harvard, Vancouver, ISO, and other styles

11

Queiroz, Clécia Maria Aquino de. "Sambando no miudinho: a estética performativa das mulheres do Recôncavo Baiano." Tabuleiro de Letras 13, no. 2 (December 26, 2019): 5. http://dx.doi.org/10.35499/tl.v13i2.7768.

Full text

Abstract:

Este trabalho analisa as configurações cênicas do samba de roda no Recôncavo Baiano, a partir das vozes e das performances das mulheres sambadeiras. Para perseguir tais objetivos, o estudo foi realizado com uma abordagem qualitativa, tendo como suporte os princípios da Etnocenologia. A análise das estéticas performativas do samba de roda do Recôncavo Baiano levou a compreensão de que elas não se resumem ao gesto, à dança ou à música. Elas são todo um complexo de percepção de si mesmo(a) e da(o) outra(o), onde o movimento, ludicidade, musicalidade e criatividade são conjugados juntos com a ambiência e relações de sociabilidade. O estudo rítmico do sapatear de algumas sambadeiras, com posterior transcrição para notação musical, apontou para a inexistência de um padrão único do passo conhecido como miudinho que difere de acordo com o estilo praticado pela comunidade de samba e com as percepções individuais das praticantes. A pesquisa ressalta ainda a importância e protagonismo das mulheres do samba de roda na organização dos eventos e na configuração dos seus procedimentos cênicos essenciais.

APA, Harvard, Vancouver, ISO, and other styles

12

Walter, P., M. Korbelik, I. Spadinger, and K. Skov. "Investigations into mechanisms of the interaction between platinum complexes and irradiation at low (∼2 Gy) doses in hypoxic cells:I. Role of single-strand breaks." Radiation Oncology Investigations 1, no. 3 (1993): 137–47. http://dx.doi.org/10.1002/roi.2970010303.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Zuo, Jing-Lin, Eberhardt Herdtweck, and Fritz E. Kühn. "Diruthenium σ-alkynyl complexes as potential building blocks for heterometallic molecular rods." Journal of the Chemical Society, Dalton Transactions, no. 7 (2002): 1244. http://dx.doi.org/10.1039/b111068n.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Dăbuleanu, Dragoș, Antonio Bauzá, Joaquín Ortega-Castro, Eduardo C. Escudero-Adán, Pablo Ballester, and Antonio Frontera. "Synthesis, X-ray Characterization and Density Functional Theory (DFT) Studies of Two Polymorphs of the α,α,α,α, Isomer of Tetra-p-Iodophenyl Tetramethyl Calix[4]pyrrole: On the Importance of Halogen Bonds." Molecules 25, no. 2 (January 10, 2020): 285. http://dx.doi.org/10.3390/molecules25020285.

Full text

Abstract:

This manuscript reports the improved synthesis of the α,α,α,α isomer of tetra-p-iodophenyl tetra-methyl calix[4]pyrrole and the X-ray characterization of two solvate polymorphs. In the solid state, the calix[4]pyrrole receptor adopts the cone conformation, including one acetonitrile molecule in its aromatic cavity by establishing four convergent hydrogen bonds between its nitrogen atom and the four pyrrole NHs of the former. The inclusion complexes pack into rods, displaying a unidirectional orientation. In turn, the rods form flat 2D-layers by alternating the orientation of their p-iodo substituents. The 2D layers stack on top of another, resulting in a head-to-head and tail-to-tail orientation of the complexes or their exclusive arrangement in a head-to-tail geometry. The dissimilar stacking of the layers yields two solvate polymorphs that are simultaneously present in the structures of the single crystals. The ratio of the two polymorph phases is regulated by the amount of acetonitrile added to the chloroform solutions from which the crystals grow. Halogen bonding interactions are highly relevant in the crystal lattices of the two polymorphs. We analyzed and characterized these interactions by means of density functional theory (DFT) calculations and several computational tools. Remarkably, single crystals of a solvate containing two acetonitrile molecules per calix[4]pyrrole were obtained from pure acetonitrile solution.

APA, Harvard, Vancouver, ISO, and other styles

15

Hill, Christopher, Wasiu Abdullahi, Robert Dalgliesh, Martin Crossman, and Peter Charles Griffiths. "Charge Modification as a Mechanism for Tunable Properties in Polymer–Surfactant Complexes." Polymers 13, no. 16 (August 20, 2021): 2800. http://dx.doi.org/10.3390/polym13162800.

Full text

Abstract:

Oppositely charged polymer–surfactant complexes are frequently explored as a function of phase space defined by the charge ratio Z, (where Z = [+polymer]/[−surfactant]), commonly accessed through the surfactant concentration. Tuning the phase behaviour and related properties of these complexes is an important tool for optimising commercial formulations; hence, understanding the relationship between Z and bulk properties is pertinent. Here, within a homologous series of cationic hydroxyethyl cellulose (cat-HEC) polymers with minor perturbations in the degree of side chain charge modification, phase space is instead explored through [+polymer] at fixed Cpolymer. The nanostructures were characterised by small-angle neutron scattering (SANS) in D2O solutions and in combination with the oppositely charged surfactant sodium dodecylsulfate (h- or d-SDS). Scattering consistent with thin rods with an average radius of ∼7.7 Å and length of ∼85 Å was observed for all cat-HEC polymers and no significant interactions were shown between the neutral HEC polymer and SDS (CSDS < CMC). For the charge-modified polymers, interactions with SDS were evident and the radius of the formed complexes grew up to ∼15 Å with increasing Z. This study demonstrates a novel approach in which the Z phase space of oppositely charged polymer–surfactant complexes can be controlled at fixed concentrations.

APA, Harvard, Vancouver, ISO, and other styles

16

Smirnova, Natalia N., and Kirill V. Smirnov. "Protein-polyelectrolyte complexes. Part 3. Complexes bovine serum albumin with sulfonate-containing aromatic poly- and copolyamides." Butlerov Communications 58, no. 4 (April 30, 2019): 66–71. http://dx.doi.org/10.37952/roi-jbc-01/19-58-4-66.

Full text

Abstract:

The interaction of bovine serum albumin in aqueous solution with sulfonate-containing poly- and copolyamides were studied. It was shown that, as a result of macromolecular reactions protein-polyelectrolyte complexes forms, stabilized mainly by electrostatic forces. To characterize the protein-polyelectrolyte complexes composition the r parameter used, which is defines as the ratio of mass concentration of polyelectrolyte and protein. It was shown that the main factor determining the composition and structure of forming protein-polyelectrolyte complexes is the degree of ionization of functional groups, interacting in the polyelectrolyte reaction that is determined by the nature of those groups and the pH of the solution. The presen ce of sulfonate and carboxylic groups in the copolyamide composition gives an extra opportunity to regulate the protein-polyelectrolyte interactions. Using spectrophotometry were established that, in the studied system when the aromatic polyamide and bovine serum albumin are mixed at optimal pH conditions (рН < 4.9), complexes are formed, the composition of which corresponds to the value of r ~ 0.15 g/g. The degree of conversation in protein-polyelectrolyte reactions is close to 0.8. The size of the formed particles was about 2.2 μm. In the case of aromatic copolyamides that contain both sulfonate and carboxylic groups, an increase in concentration of carboxylic groups to 42 mol. % leads to a shift of the optical density maximum on the curve of turbidimetric titration in to the higher r values (~ 0.18 g/g) at pH = 3.5, when the carboxylic groups are non-ionized. The size of the formed complex particles was about ~ 150.0 nm, the fraction of micron-sized particles is about 5%. The degree of released protein is based on the conditions under which reaction take place and varies from 93 to 99%. The result obtained during this work can serve as a base for the effective methods of isolation and purifying of the target proteins development.

APA, Harvard, Vancouver, ISO, and other styles

17

Ramasamy, Karthik, Weerakanya Maneerprakorn, Mohammad A. Malik, and Paul O'Brien. "Single-molecule precursor-based approaches to cobalt sulphide nanostructures." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 368, no. 1927 (September 28, 2010): 4249–60. http://dx.doi.org/10.1098/rsta.2010.0125.

Full text

Abstract:

Cobalt complexes of 1,1,5,5-tetramethyl-2,4-dithiobiuret, [Co{N(SCNMe 2 ) 2 } 3 ] ( 1 ), and 1,1,5,5-tetraisopropyl-2-thiobiuret, [Co{N(SOCN i Pr 2 ) 2 } 2 ] ( 2 ), have been synthesized and characterized. Both complexes were used as single-molecule precursors for the preparation of cobalt sulphide nanoparticles by thermolysis in hexadecylamine, octadecylamine or oleylamine. The powder X-ray diffraction pattern of as-prepared nanoparticles showed the hexagonal phase of Co 1− x S from complex 1 and mixtures of cubic and hexagonal Co 4 S 3 from complex 2 . Transmission electron microscopy images of material prepared from complex 1 showed spherical and trigonally shaped particles in the size range of 10–15 nm; whereas spheres, rods, trigonal prisms and pentagonally and hexagonally faceted crystallites were observed from complex 2 . This observation is the first of the Co 4 S 3 phase in a nanodispersed form.

APA, Harvard, Vancouver, ISO, and other styles

18

Smirnova, Natalya N. "Effect of chemical structure and linear density charge of sulfonate-containing aromatic polyamides on interaction with polycations in organic and water-organic media." Butlerov Communications 60, no. 11 (November 30, 2019): 40–47. http://dx.doi.org/10.37952/roi-jbc-01/19-60-11-40.

Full text

Abstract:

The interaction of sulfonate-containing aromatic poly- and copolyamides with acrylonitrile copolymers with N,N-dimethyl-N,N-diallylammonium chloride (DMDAAC) and N,N-diethylaminoethylmethacrylate (DEAEM) in organic and water-organic solutions was studied. It was shown that as a result of macromolecular reactions interpolyelectrolyte complexes (IPEC) forms. They are stabilized mainly by electrostatic forces. To characterize the interpolyelectrolyte complexes composition the φ parameter was used, that defines as the ratio of corresponding functional groups molar concentrations of interacting polyelectrolytes. The transformation degree in interpolymer reactions θ was calculated as the ratio of the salt bonds number between polyions to their maximum possible number. It was shown that the main factors determining the composition and structure of forming interpolyelectrolyte complexes are linear charge density of polyelectrolytes, the nature and composition of the solvent in which interpolymer reactions occurs. It is possible to obtain IPEC, the composition of which for the same polycation will vary from φ = 2.5 to φ = 1.0, changing these factors. It was found that at the complexation process is not accompanied by a change in the phase state of the interpolymer system, when the concentration of units with sulfonate groups in the macromolecular polyamide chain 5 mol.%. It was found that the introduction of polycation leads to the formation of IPEC structures in the form of particles with an average size of ~217.7 nm for poly-4,4'-(2-sodium sulfonate) – diphenylaminisophthalamide and ~248.1 nm in the case of poly-4,4'-(2-sodium sulfonate) -diphenylaminterephthalamide. It was shown that the decrease in the polymer content of units with sulfonate groups is accompanied by a decrease in the transformation degree from 0.65-0.66 to 0.18. It was found that the studied complexes can be transferred to the solution by increasing its ionic strength. The result obtained during this work can serve as a base for the development of for the manufacturing technology of film and membrane materials based on sulfonate-containing aromatic poly- and copolyamides.

APA, Harvard, Vancouver, ISO, and other styles

19

Straume, Daniel, Katarzyna Wiaroslawa Piechowiak, Silje Olsen, Gro Anita Stamsås, Kari Helene Berg, Morten Kjos, Maria Victoria Heggenhougen, Martín Alcorlo, Juan A. Hermoso, and Leiv Sigve Håvarstein. "Class A PBPs have a distinct and unique role in the construction of the pneumococcal cell wall." Proceedings of the National Academy of Sciences 117, no. 11 (March 2, 2020): 6129–38. http://dx.doi.org/10.1073/pnas.1917820117.

Full text

Abstract:

In oval-shapedStreptococcus pneumoniae, septal and longitudinal peptidoglycan syntheses are performed by independent functional complexes: the divisome and the elongasome. Penicillin-binding proteins (PBPs) were long considered the key peptidoglycan-synthesizing enzymes in these complexes. Among these were the bifunctional class A PBPs, which are both glycosyltransferases and transpeptidases, and monofunctional class B PBPs with only transpeptidase activity. Recently, however, it was established that the monofunctional class B PBPs work together with transmembrane glycosyltransferases (FtsW and RodA) from the shape, elongation, division, and sporulation (SEDS) family to make up the core peptidoglycan-synthesizing machineries within the pneumococcal divisome (FtsW/PBP2x) and elongasome (RodA/PBP2b). The function of class A PBPs is therefore now an open question. Here we utilize the peptidoglycan hydrolase CbpD that targets the septum ofS. pneumoniaecells to show that class A PBPs have an autonomous role during pneumococcal cell wall synthesis. Using assays to specifically inhibit the function of PBP2x and FtsW, we demonstrate that CbpD attacks nascent peptidoglycan synthesized by the divisome. Notably, class A PBPs could process this nascent peptidoglycan from a CbpD-sensitive to a CbpD-resistant form. The class A PBP-mediated processing was independent of divisome and elongasome activities. Class A PBPs thus constitute an autonomous functional entity which processes recently formed peptidoglycan synthesized by FtsW/PBP2×. Our results support a model in which mature pneumococcal peptidoglycan is synthesized by three functional entities, the divisome, the elongasome, and bifunctional PBPs. The latter modify existing peptidoglycan but are probably not involved in primary peptidoglycan synthesis.

APA, Harvard, Vancouver, ISO, and other styles

20

Zinovieva, Elena G., and Vladimir A. Efimov. "Complexes of metal salts of groups I-VIII with trialkyl (aryl) phosphates." Butlerov Communications 58, no. 5 (May 31, 2019): 49–53. http://dx.doi.org/10.37952/roi-jbc-01/19-58-5-49.

Full text

Abstract:

The reactions of various inorganic salts of metals of groups I-VIII in the Periodic Table with trialkyl(aryl)phosphate compounds obtained new multifunctional complexes. Modern methods of physicochemical analysis studied the laws of complexation reactions. The influence of the nature and molar ratio of the starting trialkyl(aryl)phosphates, metal salts and their crystalline hydrates on the nature of the reactions between them has been revealed. It has been shown that organic phosphates with aromatic radicals are less reactive compared to trialkylphosphates. The presence of crystallization water in metal salts leads to a decrease in the rate of their reactions with trialkyl(aryl)phosphates. The most chemically active with respect to the trialkyl(aryl)phosphate compounds were tin and titanium tetrachlorides. Synthesized metalcomplex compounds were investigated as modifiers of polymer compositions. For polymer compositions, their viability was studied, which was determined by the gelation time and the compatibility of the composition with the metal complex; hardened polymer samples were tested according to standart methods for breaking stress at break, impact strength, elongation, resistance to aggressive chemical substance and fire resistance using the fire tube method. We have developed a method of obtaining epoxy polymers by carrying out two processes – partial polymerization of the epoxy oligomer with solutions of trialkylphosphate complexes with Lewis acids in the corresponding trialkylphosphates at room temperature and the subsequent confirmation of the resulting prepolymer with triethylentetramine at 80 °C. It was revealed that trialkyl(aryl)phosphate complexes of metals are promising catalysts, modifiers and flame retardants for large-capacity polymers.

APA, Harvard, Vancouver, ISO, and other styles

21

Baeta, Sanny Rhemann, and Walter Melo. "O apoio matricial e suas relações com a teoria da complexidade." Ciência & Saúde Coletiva 25, no. 6 (June 2020): 2289–95. http://dx.doi.org/10.1590/1413-81232020256.19912018.

Full text

Abstract:

Resumo As relações entre o apoio matricial e a teoria da complexidade possuem a palavra articulação como fundamento. Dessa maneira, há o reconhecimento de que a noção de apoio matricial integra um complexo arranjo teórico-metodológico, que o insere na metodologia Paideia, colocando-o em relação ao método da roda, à clínica ampliada e compartilhada, e ao projeto terapêutico singular (PTS). O caráter técnico-assistencial e pedagógico, que caracteriza o apoio matricial, é abordado pelo aspecto de não-linearidade e de incompletude do conhecimento, possibilitando a ampliação da capacidade reflexiva de pesquisadores e, no caso em questão, de profissionais da saúde.

APA, Harvard, Vancouver, ISO, and other styles

22

Kourdioukov, Alexandre I. "Comparative DFT study of triplet and singlet elementary oxidation acts of the cyclohexane and 1,3-cyclohexadiene initiated by primary interaction with 3O2 under SCF conditions." Butlerov Communications 60, no. 11 (November 30, 2019): 128–42. http://dx.doi.org/10.37952/roi-jbc-01/19-60-11-128.

Full text

Abstract:

The primary stages of the oxidation of model cyclohexane and 1,3-cyclohexadiene by triplet molecular oxygen and subsequent transformations involving triplet and singlet states were studied for the first time by the DFT method with the density functional B3LYP with the basis set 6-311++g(df,p). It was shown that, ceteris paribus, cyclohexane and 1,3-cyclohexadiene will be orders of magnitude more reactive compared to the activity of acyclic saturated hydrocarbons under SCF conditions when the oxidation process is initiated by the primary reaction with 3O2, which allows the propane-butane mixture to be effectively used as SCF conditions of heavy oils and use air purge to activate this process. The triplet associate complexes resulting from the oxidative cleavage of the secondary C–H bond of cyclohexane and 1,3-cyclohexadiene consist of hydrogen-bonded hydroperoxyl radical and cyclohexyl radical or 1,3-cyclohexadiene radical, respectively. These complexes can dissociate into unbound pairs of radicals, and therefore further reactions can proceed in the triplet or singlet direction. The singlet direction is characterized by hydrate-induced hydroperoxide-carbonyl transformation, as well as other hydrate-induced rearrangements. The triplet direction is characterized by the occurrence of triplet rearrangement, which in its essence is a triplet recombination of associated radicals. Associate triplet complexes can be agents of radical hydroperoxyl and alkyl activity, as well as agents of radical hydroxyl and alkoxyl activity. Most oxidative dehydrogenation reactions are absolutely real under a number of conditions, namely, they must take place under SCF conditions, as well as in the presence of an excess of SCF solvent necessary for the effective shift of thermodynamic equilibrium towards the target products in accordance with the Le Chatelier principle.

APA, Harvard, Vancouver, ISO, and other styles

23

Ismailov, Namig I., and Sevinj N. Osmanova. "Azo-substituted ethoxyacridine – reagents for the extraction-photometric determination of gallium." Butlerov Communications 58, no. 5 (May 31, 2019): 70–74. http://dx.doi.org/10.37952/roi-jbc-01/19-58-5-70.

Full text

Abstract:

The associates of halide (chloride) complexes of gallim azo-substituted ethoxyacridine have been studied by spectrophotometric method. It has been found that the associates are well extracted with a mixture of dichloroethane-acetone (3:2). The optimum volume of aqueous and organic phase is equal to 5 ml. The molar ratio of the components in the extractable compounds was studied by the methods of isomolar series, equilibrium shift and a straight line. It was found that gallium chloride associated with azo-ethoxyacridines (AE) in a ratio of 1:1. It was studied formation and extraction of associates of gallium chloride with AEADPA (2-ethoxy-6-(4-N,N-dipropylphenylazo)-9-aminoacridine) and AEAN (2-ethoxy-6-(2-hydroxynaphthylazo)-9aminoacridine). The maxima of light absorption of gallium chloride with AEADPA is observed at 520 nm, and the AEAN at 510 nm. The light absorption of the extracts of associates coincides with the absorption maxima of azoethoxyacridines, which indicates the electrostatic character of the interaction and the formation of complexes. Study of the effect of foreign ions on the accuracy of the determination of gallium with azo-substituted ethoxyacridine showed that the number of ions does not interfere (in parentheses are multiple relationships to gallium ions); Zn2+ (2000), NiII (1500), CuII (2500), CoII (1400), Cr III(1100), PbI (2250), Al3+(1600), Cd2+(700), FeII (1050), ReVII (500), PdIII (1200), Tl (2500). Number of ions interfered the determination: TeIV(1), FeIII (1), AuIII (1), SbV(1), TlIII(1), SeIV(3). The physico-chemical and analytical characteristics of the azo-substituted ethoxyacridines and their ionic associates with chloride gallium acidic complexes (λmax ε, βkD, D, R%) were determined. It was shown that chloro-gallium compounds with azo-substituted ethoxyacridines are ionic associates, the molar ratios of the components in which are: [Ga3+] : [Cl-] : R+ = 1:4:1.

APA, Harvard, Vancouver, ISO, and other styles

24

Tsurusaki, Tatsuya, and Takeshi Ohgai. "Mechanical Properties of Solder-Jointed Copper Rods with Electrodeposited Sn-Zn Alloy Films." Materials 13, no. 6 (March 14, 2020): 1330. http://dx.doi.org/10.3390/ma13061330.

Full text

Abstract:

Enforced solid solution type Sn-Zn alloy films were electrochemically synthesized on Cu substrate from an aqueous solution containing citric acid complexes. The electrodeposition behavior of Sn-Zn alloys was classified to a normal co-deposition type, in which electrochemically nobler Sn deposits preferentially compared to Zn. Electrodeposited Sn-Zn alloy films were composed of a non-equilibrium phase, like an enforced solid solution, which was not observed in an equilibrium phase diagram of an Sn-Zn binary alloy system. By applying a thermal annealing process at 150 °C for 10 minutes, a pure Zn phase was precipitated from an electrodeposited Sn-based solid solution phase with excessively dissolved Zn atoms. During the soldering process, intermetallic phases such as Cu3Sn and Cu5Zn8 were formed at the interface between an Sn-Zn alloy and Cu substrate. Tensile strength and fracture elongation of solder-jointed Cu rods with Sn-8 at.%Zn alloy films reached ca. 40 MPa and 12%, respectively.

APA, Harvard, Vancouver, ISO, and other styles

25

Garcia, Galo, Gregory C. Finnigan, Lydia R. Heasley, Sarah M. Sterling, Adeeti Aggarwal, Chad G. Pearson, Eva Nogales, Michael A. McMurray, and Jeremy Thorner. "Assembly, molecular organization, and membrane-binding properties of development-specific septins." Journal of Cell Biology 212, no. 5 (February 29, 2016): 515–29. http://dx.doi.org/10.1083/jcb.201511029.

Full text

Abstract:

Septin complexes display remarkable plasticity in subunit composition, yet how a new subunit assembled into higher-order structures confers different functions is not fully understood. Here, this question is addressed in budding yeast, where during meiosis Spr3 and Spr28 replace the mitotic septin subunits Cdc12 and Cdc11 (and Shs1), respectively. In vitro, the sole stable complex that contains both meiosis-specific septins is a linear Spr28–Spr3–Cdc3–Cdc10–Cdc10–Cdc3–Spr3–Spr28 hetero-octamer. Only coexpressed Spr3 and Spr28 colocalize with Cdc3 and Cdc10 in mitotic cells, indicating that incorporation requires a Spr28-Spr3 protomer. Unlike their mitotic counterparts, Spr28-Spr3–capped rods are unable to form higher-order structures in solution but assemble to form long paired filaments on lipid monolayers containing phosphatidylinositol-4,5-bisphosphate, mimicking presence of this phosphoinositide in the prospore membrane. Spr28 and Spr3 fail to rescue the lethality of a cdc11Δ cdc12Δ mutant, and Cdc11 and Cdc12 fail to restore sporulation proficiency to spr3Δ/spr3Δ spr28Δ/spr28Δ diploids. Thus, specific meiotic and mitotic subunits endow septin complexes with functionally distinct properties.

APA, Harvard, Vancouver, ISO, and other styles

26

Khan, Anum, Jay Newby, and Amy S. Gladfelter. "Control of septin filament flexibility and bundling by subunit composition and nucleotide interactions." Molecular Biology of the Cell 29, no. 6 (March 15, 2018): 702–12. http://dx.doi.org/10.1091/mbc.e17-10-0608.

Full text

Abstract:

Septins self-assemble into heteromeric rods and filaments to act as scaffolds and modulate membrane properties. How cells tune the biophysical properties of septin filaments to control filament flexibility and length, and in turn the size, shape, and position of higher-order septin structures, is not well understood. We examined how rod composition and nucleotide availability influence physical properties of septins such as annealing, fragmentation, bundling, and bending. We found that septin complexes have symmetric termini, even when both Shs1 and Cdc11 are coexpressed. The relative proportion of Cdc11/Shs1 septin complexes controls the biophysical properties of filaments and influences the rate of annealing, fragmentation, and filament flexibility. Additionally, the presence and apparent exchange of guanine nucleotide also alters filament length and bundling. An Shs1 mutant that is predicted to alter nucleotide hydrolysis has altered filament length and dynamics in cells and impacts cell morphogenesis. These data show that modulating filament properties through rod composition and nucleotide binding can control formation of septin assemblies that have distinct physical properties and functions.

APA, Harvard, Vancouver, ISO, and other styles

27

Adeyemi, Jerry O., and Damian C. Onwudiwe. "PbS Nanoparticles Prepared Using 1, 10-Phenanthroline Adduct of Lead(II) Bis(N-alkyl-N-phenyl dithiocarbamate) as Single Source Precursors." Molecules 25, no. 9 (April 30, 2020): 2097. http://dx.doi.org/10.3390/molecules25092097.

Full text

Abstract:

Dithiocarbamate complexes have remained prominent as single source precursors for the synthesis of clean metal sulfide nanoparticles. This study reports the synthesis of lead sulfide (PbS) nanoparticles using some novel complexes of 1, 10-phenanthroline lead(II) bis(N-alkyl-N-phenyl dithiocarbamate), represented as [Pb(L1)2phen] (1) and [Pb(L2)2phen] (2) (where L1 = bis(N-ethyl-N-phenyldithiocarbamate; L2 = bis(N-butyl-N-phenyldithiocarbamate); phen = 1, 10 phenanthroline) as a single source precursors. The complexes (1 and 2) were synthesized and characterized using various spectroscopic techniques and elemental analysis. The nanoparticles were synthesized via a solvothermal approach in oleylamine, used as a capping agent, and were given as PbS(1) and PbS(2) from [Pb(L1)2phen] (1) and [Pb(L2)2phen] (2), respectively, which were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), and absorption spectroscopy. The diffraction patterns confirmed the formation of face-centered cubic phase PbS nanoparticles with a preferential growth orientation along the (200) plane. The TEM images showed that PbS(1) were of a spherical morphology, while the morphology of PbS(2) tended to produce short rods. This was due to variation in the functional group on the precursor compounds. This variation also resulted in the different band gap energies found such as 1.148 and 1.107 eV for PbS(1) and PbS(2), respectively, indicating a blue shift from the bulk.

APA, Harvard, Vancouver, ISO, and other styles

28

Kurshev, Nikita I. "Theoretical study of dimethylcarbonate production by urea alcoholysis." Butlerov Communications 62, no. 4 (April 30, 2020): 38–50. http://dx.doi.org/10.37952/roi-jbc-01/20-62-4-38.

Full text

Abstract:

Using the density functional method М06, the mechanisms of non-catalytic reactions of transesterification of urea with methanol with the formation of dimethyl carbonate, as well as in catalysis with zinc oxide and acetate, were studied. The transesterification proceeds stepwise with the intermediate formation of methyl carbamate. The non-catalytic process of transesterification of urea with methanol proceeds by the mechanism of nucleophilic SN2 substitution and is accompanied by the formation of pre-reaction complexes, which through synchronous transition states turn into post-reaction complexes, decomposing into ammonia and methyl carbamate in the first stage and dimethyl carbonate in the second. It has been established that methanol associates can take part in these reactions. Their participation is preferable both kinetically and thermodynamically. An analysis of the equilibrium constants of the reaction of urea with methanol at various temperatures showed that in a wide temperature range their values remain large in the first stage – the formation of methyl carbamate and become significantly reversible in the second – the conversion of methyl carbamate to dimethyl carbonate. Reactions involving acetate and zinc oxide proceed through the same stages as non-catalytic interactions. In the case of zinc acetate catalyzed reactions, if methanol monomer is involved in the reaction, the reaction of formation of methyl carbamate has a lower activation barrier compared to the reaction of conversion of methyl carbamate to dimethyl carbonate. If a methanol dimer is involved in the reaction, both reactions have a practically equal activation barrier. In the case of zinc oxide catalyzed interactions, reactions involving a methanol dimer were not detected. The participation of the catalyst leads to a significant decrease in activation barriers, and a more significant decrease occurs in the case of catalysis with zinc oxide. The reason for the different catalytic activity, in our opinion, is the difference in the charges on the urea carbon atom in the pre-reaction complexes.

APA, Harvard, Vancouver, ISO, and other styles

29

Wawrzyniak, Urszula E, Mateusz Woźny, Jarosław Kowalski, Sławomir Domagała, Elwira Maicka, Renata Bilewicz, Krzysztof Woźniak, and Bohdan Korybut-Daszkiewicz. "Neutral Nickel(II) and Copper(II) Tetraazamacrocyclic Complexes as Molecular Rods Attached to Gold Electrodes." Chemistry - A European Journal 15, no. 1 (January 2009): 149–57. http://dx.doi.org/10.1002/chem.200801689.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Johnson Martinho, Neudson, Victor Hugo Martins Santos, Cristiane Maria Amorim Costa, Cristiano Bertolossi Marta, Edneiva Dos Santos Bacani, Rosaní Siqueira Viana Morae, and Karoline Cristine Aparecida Ribeiro Ramos. "Dificuldades enfrentadas no acesso à saúde por usuários LGBT." Saúde Coletiva (Barueri), no. 58 (November 23, 2020): 3841–48. http://dx.doi.org/10.36489/saudecoletiva.2020v10i58p3841-3848.

Full text

Abstract:

Os problemas enfrentados quanto ao acesso aos serviços de saúde pelos usuários LGBT ainda são complexos, de modo específico, nos casos das travestis e transexuais. Este é o recorte de um projeto de pesquisa com abordagem qualitativa, o qual objetiva desvelar as percepções dos LGBT quanto aos atendimentos que recebem nos serviços de saúde de Cuiabá – MT. Foi utilizada a metodologia da roda de conversas para coleta de dados. Os sujeitos referiram despreparo dos profissionais da saúde no acolhimento e atendimento às suas demandas, demonstrando que a academia não os prepara para este tipo de atenção específica e nem as políticas de saúde integral à saúde LGBT estão efetivadas na prática. Espaços de fala e escuta possibilitam aos sujeitos expressarem seus sentimentos e vivências, permitindo-os expressar como deveria ser o atendimento à saúde com equidade e qualidade.

APA, Harvard, Vancouver, ISO, and other styles

31

Mukhina, Veronika A., Veronika A. Prikhodko, Nadezhda V. Kirillova, Natalia A. Anisimova, and Alexey G. Ivanov. "Insulin-mimetic macromolecular poly-N-vinylpyrrolidone-based vanadium metallocomplexes. Part 2. Assessment of the hypoglycemic activity of the vanadium macromolecular metal complex." Butlerov Communications 59, no. 9 (September 30, 2019): 110–16. http://dx.doi.org/10.37952/roi-jbc-01/19-59-9-110.

Full text

Abstract:

In a previous work, a method for the synthesis of a new metal-polymer complex of oxovanadium (IV) based on poly-N-vinylpyrrolidone was described, its structure was studied by spectral methods, and its composition was determined. Based on the data of electronic and vibrational spectroscopy, it was shown that the complex is formed due to the interaction of the metal with nitrogen and oxygen atoms of the polymer lactam ring, it should be noted that this type of interaction can occur both by intramolecular or intermolecular coordination. Using the Prozorovsky’s express method for estimation of acute oral toxicity the median value of LD50 of the synthesized complex was determined and it amounted to 1350 ± 160 mg/kg. The obtained LD50 value allow to attribute this metal-polymer complex to the class of low-toxic substances, which opens up some prospects for its further research on insulinomimetic activity. The aim of this work is to investigate the hypoglycemic activity of new polymer derivatives of vanadyl (VO2+) based on poly-N-vinylpyrrolidone (PVP) and to explore the possibility of using these compounds or compositions based on them for the prevention and treatment of type 2 diabetes. The work describes a method for creating an experimental model of type 2 diabetes mellitus in animals, combining the use of a high-fat diet and streptozotocin as a diabetogenic agent. The results of evaluating the effect of the studied metal-polymer complexes on such indicators of carbohydrate metabolism of laboratory animals as changes in blood glucose and urine, change daily diuresis of animals during treatment. The results of evaluating the effect of the metal-polymer complexes on such indicators of carbohydrate metabolism in laboratory animals as a change in blood and urine glucose, a change in the daily diuresis of animals during and after treatment are presented. The investigation of the effect of the obtained vanadium compounds on carbohydrate indices was carried out using metformin as a comparison drug. It was found that the new metal-polymer complexes of vanadium have hypoglycemic activity, normalizing the blood glucose level of laboratory animals with high-fat diet/ streptozotocin induced diabetes.

APA, Harvard, Vancouver, ISO, and other styles

32

HAUCK, J., and K. MIKA. "CRYSTAL HABIT OF MINERALS — A CRYSTAL CHEMICAL APPROACH." International Journal of Modern Physics B 21, no. 06 (March 10, 2007): 871–83. http://dx.doi.org/10.1142/s0217979207036734.

Full text

Abstract:

Homogeneous particles A like carbon atoms in diamond, CO 3 ions in CaCO 3, or sulfur molecules in sulfur with different A–A interactions are ordered in such a way that the bulk structure can be characterized by the self-coordination numbers T i, i = 1-3, of nearest, second, and third neighbors. There are about 500 sets with increased Ti values and about 500 sets with reduced Ti values, which can be obtained from characteristic lattice complexes. The different sets with increased Ti values are characterized by S, L, or R for sphere, layer, or rod packing. Two or more particles A, B, C, etc., can belong to the same set like Na and Cl atoms in NaCl or different sets like Ca and F atoms in CaF 2. The Dirichlet domains of A and B ( CaF 2) or A + B ( NaCl ) are approaches to the morphological lattices (cubes or rhombododecahedra). Planes with a high density of A positions and thus low h k l values like the {111} planes of octahedra are derived from Bravais' theory. The morphological lattices of layer or rod packings are layers or rods because of the increased densities of A in layers or rods.

APA, Harvard, Vancouver, ISO, and other styles

33

Gacki, Michał, Karolina Kafarska, Anna Pietrzak, Izabela Korona-Głowniak, and Wojciech M. Wolf. "Double Palindrome Water Chain in Cu(II) Theophylline Complex. Synthesis, Characterization, Biological Activity of Cu(II), Zn(II) Complexes with Theophylline." Crystals 10, no. 2 (February 8, 2020): 97. http://dx.doi.org/10.3390/cryst10020097.

Full text

Abstract:

Two metal complexes of theophylline were synthesized. Namely, 1 with the formula [Cu(theop)2(H2O)3]·2H2O and 2, [Zn(theop)2]∙H2O (where: theop = theophylline ion). Their properties were thoroughly investigated by the elemental analysis (EA), flame atomic absorption spectrometry (FAAS), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA) that were augmented by antimicrobial and antioxidant analyses. Their radical scavenging ability (RSA) is notably higher than that of a pure theophylline itself. Similarly to theophylline complexes already studied by us 3, [Mn(theop)2(H2O)4] 4, [Co(theop)2(H2O)4] and 5, [Ni(theop)2(H2O)4] title compounds are inactive against Gram-negative bacteria, but they show moderate or mild activity against Gram-positive rods. The low temperature, single crystal X-ray diffraction technique determines the crystal structure of 1. Its supramolecular crystal topology is affected by the unique, double palindrome water chain that formed by two conserved and a sole coordinated water molecules. Crystal packing arrangements were characterized by fingerprint plots that were derived from the Hirshfeld surfaces (HS), as calculated for all structures in the series 1, 3, 4, 5.

APA, Harvard, Vancouver, ISO, and other styles

34

Li, Ying, Han Gong, Rui Zhan, Shushan Ouyang, Kyung-Tae Park, Joe Lutkenhaus, and Shishen Du. "Genetic analysis of the septal peptidoglycan synthase FtsWI complex supports a conserved activation mechanism for SEDS-bPBP complexes." PLOS Genetics 17, no. 4 (April 15, 2021): e1009366. http://dx.doi.org/10.1371/journal.pgen.1009366.

Full text

Abstract:

SEDS family peptidoglycan (PG) glycosyltransferases, RodA and FtsW, require their cognate transpeptidases PBP2 and FtsI (class B penicillin binding proteins) to synthesize PG along the cell cylinder and at the septum, respectively. The activities of these SEDS-bPBPs complexes are tightly regulated to ensure proper cell elongation and division. In Escherichia coli FtsN switches FtsA and FtsQLB to the active forms that synergize to stimulate FtsWI, but the exact mechanism is not well understood. Previously, we isolated an activation mutation in ftsW (M269I) that allows cell division with reduced FtsN function. To try to understand the basis for activation we isolated additional substitutions at this position and found that only the original substitution produced an active mutant whereas drastic changes resulted in an inactive mutant. In another approach we isolated suppressors of an inactive FtsL mutant and obtained FtsWE289G and FtsIK211I and found they bypassed FtsN. Epistatic analysis of these mutations and others confirmed that the FtsN-triggered activation signal goes from FtsQLB to FtsI to FtsW. Mapping these mutations, as well as others affecting the activity of FtsWI, on the RodA-PBP2 structure revealed they are located at the interaction interface between the extracellular loop 4 (ECL4) of FtsW and the pedestal domain of FtsI (PBP3). This supports a model in which the interaction between the ECL4 of SEDS proteins and the pedestal domain of their cognate bPBPs plays a critical role in the activation mechanism.

APA, Harvard, Vancouver, ISO, and other styles

35

Koroteev, Alexander M., Garry Z. Kaziev, Mikhail P. Koroteev, Anna F. Stepnova, Anton O. Pozdeev, Valery P. Zinchenko, Alexander I. Sergeev, and Evgeny N. Ofitserov. "Transformation of hydrophobic flavonoids catechin, dihydroquercetin and quercetin into water-soluble structures." Butlerov Communications 64, no. 10 (October 31, 2020): 14–21. http://dx.doi.org/10.37952/roi-jbc-01/20-64-10-14.

Full text

Abstract:

The paper describes methods for the transformation of poorly water-soluble flavonoids: dihydroquercetin, catechin and quercetin into water-soluble forms during the formation of supromolecular adducts with β-cyclodextrin and salt-type ionic complexes with the natural amino acid L-arginine, which contains a guanidine moiety properties necessary to create a cationic structure when interacting with phenolic groups. First, a methodology was developed for the synthesis of supromolecular structures, in which flavonoids were incorporated into a cyclodextrin matrix. As a result, the solubility in water at 20 °C of encapsulated flavonoids increased by more than two orders of magnitude. In the formation of complexes of cyclodextrin with flavonoids, the main role is played not by hydrogen bonds between the hydroxyl groups of flavonoids and β-cyclodextrin - in the case of dihydroquercetin and catechin, they are different and similar in the case of dihydroquercetin and quercetin, but the spatial orientation of the pyrocatechol cycle B (due to the flat conjugation of the entire molecule and due to sp2 is the structure of the second carbon atom of the pyran ring). Another implemented approach for obtaining water-soluble flavonoids at room temperature is the creation of their salts with the natural amino acid L-arginine, which is a part of proteins and is involved in several vital processes in the body. The structure of the obtained compounds was proved by the methods of NMR spectroscopy on 13C nuclei and X-ray structural analysis, the composition – by elemental analysis.

APA, Harvard, Vancouver, ISO, and other styles

36

Loeb, S. J., S. L. Murphy, and J. A. Wisner. "Crystal engineering with molecular rods: binuclear complexes of bridging, nitrogen-donor ligands capped by organopalladium fragments." Crystal Engineering 2, no. 1 (September 1999): 27–36. http://dx.doi.org/10.1016/s1463-0184(99)00004-0.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Makarova, Anna A., Elena V. Grachova, Dmitry V. Krupenya, Oleg Vilkov, Alexander Fedorov, Dmitry Usachov, Alexander Generalov, et al. "Self-Assembled Supramolecular Complexes with “Rods-in-Belt” Architecture in the Light of Soft X-rays." Journal of Physical Chemistry C 117, no. 23 (June 4, 2013): 12385–92. http://dx.doi.org/10.1021/jp404459k.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Damzina, Anna А., Lidia N. Skvortsova, and Konstantin A. Bolgaru. "Oxidative photo-catalytic destruction of eosine with the application of iron-contalning metal-ceramic composites with additive complex-forming reagents." Butlerov Communications 60, no. 11 (November 30, 2019): 21–30. http://dx.doi.org/10.37952/roi-jbc-01/19-60-11-21.

Full text

Abstract:

Iron-containing metal-ceramic composites based on nitrogen and sialon nitrides, obtained by the method of self-propagated synthesis were studied in the process of photocatalytic oxidative destruction of eosin. The phase composition of the samples was established by the X-ray diffraction method. It was shown that, along with the main phases, the ceramic matrix of materials contains the phases of semiconductors: (SiC, TiN). The indicator method of Hammet and Tanabe assessed the surface acid-base centers of the composites. It was established that a large sorption of the dye is characteristic of samples based on silicon nitride and sialon and is associated with the participation of active Brensted acid sites. The photocatalytic activity of iron-containing composites was studied in the presence of H2O2 (photo-Fenton system), H2O2 and EDTA (peroxide-ferriccomplexon system), H2O2 and tartaric acid (peroxide-ferritartrate system). It was shown that the degree of oxidative destruction of eosin is significantly higher with the participation of Fe(II, III) complexes with EDTA and tartaric acid, than Fe(II, III) aquacomplexes in the photo-Feton system. The high activity of composites containing the semiconductor phase of titanium nitride (TiN) is due to the combination of homogeneous and heterogeneous catalysis with the participation of the ceramic matrix. The introduction of complexing agents shifts the optimal acidity (pH 2-4) for a homogeneous system of photo-Fenton with the participation of iron(II, III) aqua complexes in the weakly acidic region (pH 4-7) and leads to almost complete destruction of the dye in the peroxide-tartrate system.

APA, Harvard, Vancouver, ISO, and other styles

39

Kimyashov, Alexander A., Alexander V. Syromolotov, and Dmitry S. Ryashincev. "Study of Buchwald-Hartwig reaction with catalysts based on monovalent copper." Butlerov Communications 58, no. 4 (April 30, 2019): 62–65. http://dx.doi.org/10.37952/roi-jbc-01/19-58-4-62.

Full text

Abstract:

Many natural substances and drugs includes N-aryl-substituted heterocycles. These substances can be synthesized in various conditions, one of which is the amination of Buchwald-Hartwig. In this reaction formation of N-substituted anilines was observed as the resalt of the interaction between aryl halides and tin amides in palladium catalysis condition. It was discovered by Buchwald and Hartwig in 1994. In 1996, toxic amides of tin and P(o-Tol)3 were replaced by amines and chelating diphosphines. Due to high yields and good reproducibility, Buchwald-Hartwig amination is the attractive method for producing aromatic amines. Currently, this amination is carried out with triphenylphosphine palladium complexes. The main drawback of these catalysts is the high cost and toxicity. In this regard, work is underway to replace these catalysts on copper containing. Currently using complexes of monovalent copper with the following chelating agents: diamines, amino acids, 1,10-phenanthroline, diols. In this work, we studied the reaction of C-N cross-combination using a catalytic system based on a complex of monovalent copper and 1-ethylbenzimidazole. The efficiency of this catalytic system is compared with the copper – L proline system described in the literature. It is shown that the use of copper – 1-ethyl-benzimidazole system can reduce the synthesis time from forty hours to twelve. It is established that the presence of the acceptor substituent in the substrate increase the yield of the product in the Buchwald-Hartwig reaction. Indole was used as a substrate. Arylation was carried out by iodobenzene, o-iodotoluene and p-iodnitrobenzen.

APA, Harvard, Vancouver, ISO, and other styles

40

Nazarova, Anastasia A., Alsu I. Gilyazeva, and Ivan I. Stoykov. "The solvent nature influence on the self-assembly of monosubstituted pillar[5]arenes containing N-(aminoalkyl)amide fragment." Butlerov Communications 63, no. 7 (July 31, 2020): 1–10. http://dx.doi.org/10.37952/roi-jbc-01/20-63-7-1.

Full text

Abstract:

Chemistry of macrocyclic compounds is one of the rapidly developing areas of modern organic chemistry. These macrocycles have become widespread due to the high availability of parents compounds, the possibility of synthesis of ligands based on them for highly selective recognition, ion-selective membranes, electrodes, sensors and nanocontainers for targeted drug delivery. Moreover, in the past few years, attention of researchers has again been riveted on mechanically interlocked molecules (rotaxanes and pseudorotaxans) and supramolecular polymers, which can be explained by their potential application as molecular machines and materials. Mechanically interlocked molecules are molecular architectures consisting from two or more components which mechanically bind due to their own topology. Supramolecular polymers are comprise ordered monomer units combined via non-covalent bonds (hydrogen bonds or electrostatic interactions). Thus, this manuscript presents an approach to the synthesis of monosubstituted pillar[5]arenes containing N-(aminoalkyl)amide fragments with various substituent lengths. The formation of self-inclusion complexes by synthesized macrocycles was established by one- and two-dimensional NMR spectroscopy. According to NMR data, only four carbon atoms of the alkyl fragment were included in the macrocyclic cavity regardless of the alkyl chain length. Formation of self-inclusion complexes becomes possible due to the intramolecular hydrogen bond between the NH protons and the oxygen atom of methoxyl fragment, which is confirmed by IR spectroscopy. It was shown by dynamic light scattering that the synthesized pillar[5]arenes in chloroform form aggregates with an average hydrodynamic diameter of 316-640 nm and polydispersity index from 0.18 to 0.20, while polydisperse systems are formed in dimethyl sulfoxide.

APA, Harvard, Vancouver, ISO, and other styles

41

Jovanovic, Goran, Parul Mehta, Liming Ying, and Martin Buck. "Anionic lipids and the cytoskeletal proteins MreB and RodZ define the spatio-temporal distribution and function of membrane stress controller PspA in Escherichia coli." Microbiology 160, no. 11 (November 1, 2014): 2374–86. http://dx.doi.org/10.1099/mic.0.078527-0.

Full text

Abstract:

All cell types must maintain the integrity of their membranes. The conserved bacterial membrane-associated protein PspA is a major effector acting upon extracytoplasmic stress and is implicated in protection of the inner membrane of pathogens, formation of biofilms and multi-drug-resistant persister cells. PspA and its homologues in Gram-positive bacteria and archaea protect the cell envelope whilst also supporting thylakoid biogenesis in cyanobacteria and higher plants. In enterobacteria, PspA is a dual function protein negatively regulating the Psp system in the absence of stress and acting as an effector of membrane integrity upon stress. We show that in Escherichia coli the low-order oligomeric PspA regulatory complex associates with cardiolipin-rich, curved polar inner membrane regions. There, cardiolipin and the flotillin 1 homologue YqiK support the PspBC sensors in transducing a membrane stress signal to the PspA-PspF inhibitory complex. After stress perception, PspA high-order oligomeric effector complexes initially assemble in polar membrane regions. Subsequently, the discrete spatial distribution and dynamics of PspA effector(s) in lateral membrane regions depend on the actin homologue MreB and the peptidoglycan machinery protein RodZ. The consequences of loss of cytoplasmic membrane anionic lipids, MreB, RodZ and/or YqiK suggest that the mode of action of the PspA effector is closely associated with cell envelope organization.

APA, Harvard, Vancouver, ISO, and other styles

42

Bari, Valéria Aparecida, and Shirley dos Santos Ferreira. "APROPRIAÇÃO DA LEITURA LITERÁRIA POR MEIO DAS HISTÓRIAS EM QUADRINHOS: PRÁTICA DA EDUCOMUNICAÇÃO." Interfaces Científicas - Educação 5, no. 2 (February 22, 2017): 29–40. http://dx.doi.org/10.17564/2316-3828.2017v5n2p29-40.

Full text

Abstract:

Discute como a prática educomunicativa favorece a mediação da leitura literária, por meio da utilização da linguagem das histórias em quadrinhos, como recurso de adaptação e clarificação de conteúdos complexos. Para verificação dessa premissa, foi elaborada atividade de Roda de Leitura com a adaptação em quadrinhos do poema épico de Gonçalves Dias, I-Juca Pirama. A partir da adaptação para a linguagem dos quadrinhos, de autoria de Silvino, mais elementos foram acrescentados à narrativa, uma vez que os efeitos poéticos e a linguagem rebuscada se hibridizam com imagens que aprofundam a ação e a afetividade. Por meio de uma vivência desenvolvida em celebração ao Dia do Índio, no Museu Histórico de Sergipe (MHSE), foram elaboradas análises sobre a apropriação de diferentes segmentos da população, com identidades sociais assumidas como indígenas e descendentes e população mestiça branco/parda aculturada.

APA, Harvard, Vancouver, ISO, and other styles

43

Korolev, Arkadii, Anna Kochkina, and Dmitry Stashenkov. "The Early Eneolithic burial ground at Ekaterinovsky Cape in the forest-steppe Volga region." Documenta Praehistorica 46 (December 9, 2019): 388–97. http://dx.doi.org/10.4312/dp.46-24.

Full text

Abstract:

The Ekaterinovsky Cape burial ground is located on the territory of the Samara region of Russia on the left bank of the River Volga. The excavation of the burial ground was carried out in 2013–2018. During this time we studied 100 graves, including sacrificial sites with ceramics of collar type and sacrificial complexes. Most of the skeletons were in an extended position on their backs. There are some skeletons on their backs with legs bent at the knees, secondary burials and separate burials of skulls. Ochre was used. The inventory included beads made from shells, stone products, animal teeth, bones and horns. There we distinguished graves with stone sceptres and zoomorphic rods made from the horn. The burial ground belongs to the Samara culture and dates from the second half of the 6th millennium BC.

APA, Harvard, Vancouver, ISO, and other styles

44

Korolev, Arkadii, Anna Kochkina, and Dmitry Stashenkov. "The Early Eneolithic burial ground at Ekaterinovsky Cape in the forest-steppe Volga region." Documenta Praehistorica 46 (December 9, 2019): 388–97. http://dx.doi.org/10.4312/dp.46.24.

Full text

Abstract:

The Ekaterinovsky Cape burial ground is located on the territory of the Samara region of Russia on the left bank of the River Volga. The excavation of the burial ground was carried out in 2013–2018. During this time we studied 100 graves, including sacrificial sites with ceramics of collar type and sacrificial complexes. Most of the skeletons were in an extended position on their backs. There are some skeletons on their backs with legs bent at the knees, secondary burials and separate burials of skulls. Ochre was used. The inventory included beads made from shells, stone products, animal teeth, bones and horns. There we distinguished graves with stone sceptres and zoomorphic rods made from the horn. The burial ground belongs to the Samara culture and dates from the second half of the 6th millennium BC.

APA, Harvard, Vancouver, ISO, and other styles

45

Mukhamedyarova, Lilia I., Sergey G. Bezryadin, Elena Yu Klukvina, Vladimir V. Chevela, and Valentina Yu Ivanova. "Composition, stability and stereo effects of zirconium(IV) dl-tartrate formation." Butlerov Communications 57, no. 2 (February 28, 2019): 28–34. http://dx.doi.org/10.37952/roi-jbc-01/19-57-2-28.

Full text

Abstract:

The system of zirconium (IV) – dl-tartaric acid for metal: ligand 1: 1, 1: 2 and 1: 3 ratios in aqueous solution has been studied by means of using potentiometric titration method in combination with mathematical modeling. The comparison of Bjerrum functions from pH for zirconium(IV) systems: d-tartaric acid and zirconium (IV): dl-tartaric acid, has revealed the following features in the behavior of the curves: the degree of titration for the complexes at a fixed pH value for systems with dl-tartaric acid is more than for d-acid. The CPESSP software complex has calculated the composition, stability constants and molar fractions of zirconium(IV) tartrate accumulation. It has been also found that at a ratio of 1: 1 for Zr (IV) and ligand (H4Tart) ions in the system under study ZrHTart+ is formed, which is tetramerized into Zr4Tart40 and, further, tetranuclear particles of varying degrees of deprotonization are formed, as well as mononuclear forms. In a strongly alkaline pH environment > 10, Bjerrum curves for d- and dl-tartaric acids overlap each other and correspond to hydroxocomplexes of varying degrees of titration. For the 1: 2 ratio, the composition of the complexes for the zirconium(IV) – dl-H4T system is slightly different; compared to the zirconium(IV) – dH4T system, differences are clearly observed for both low and high concentrations. Based on these data, a complex formation scheme in the Zr(IV) – dl-tartaric acid system has been proposed for all the ratios studied. The characteristics of stereoselective diastereomer formation have been calculated. It has been revealed that in the medium of racemic tartrate, ddd- and lll-Zr(H2Tart)2(HTart)3-forms, as well as Zr(H2Tart)(НTart)24-Zr(HTart)35- are formed on a stereoselective basis.

APA, Harvard, Vancouver, ISO, and other styles

46

Grishin, Vladimir V., Vladimir V. Grishin, Elizaveta N. Kanyuka, Denis V. Solovey, Irina S. Ivanova, Alexey S. Popov, Alexander S. Chukhno, Anna V. Zamyatina, and Mikhail E. Zhalko. "Investigation of the effect of antibiotics on the rate of remineralization of tooth enamel." Butlerov Communications 63, no. 7 (July 31, 2020): 85–91. http://dx.doi.org/10.37952/roi-jbc-01/20-63-7-85.

Full text

Abstract:

The safety of antibiotics is still debatable. The properties of large molecules to give insoluble compounds with metal ions leads to a decrease of absorption of active components and most often loss of biological activity. Depending on the presence of functional groups in the side chain, the formation of complexes of different strength is possible. The properties of a number of antibiotics to interact with calcium ions allow us to expect the interaction of these antibiotics with the surface of the tooth enamel along the calcium centers. The alkaline environment of the oral cavity and the excess of calcium ions in the saliva, in comparison with phosphate residues, make it possible to make available the calcium centers of the hydroxyapatite crystal. The strength of this complex will be determined by the structure and functional substituents of the antibiotic molecule and will not depend much on its charge. In this article the effect of broad-spectrum antibiotics on the remineralizing ability of saliva in relation to tooth enamel based on the experiments performed on teeth is discussed. The analysis of the degree of remineralization function of saliva was carried out by means of spectrophotometric determination of the stability of calcium complexes with individual broad-spectrum antibiotics at different multiplicity of individual components. As a result of setting up an experiment to restore tooth enamel after treatment with these solutions of antibiotics, the characteristic assessment of which is the presence of sites of remineralization and their size on the surface of the tooth enamel for certain periods of time and in comparison with the standard, it was concluded that antibiotic solutions reduce the remineralization ability of saliva to restore the outer surface of the enamel of teeth.

APA, Harvard, Vancouver, ISO, and other styles

47

Degtyarev, Andrey A., and Alexandra V. Trishina. "Research the sulfonation mechanism of urea in oleum by density functional theory calculation." Butlerov Communications 59, no. 8 (August 31, 2019): 32–39. http://dx.doi.org/10.37952/roi-jbc-01/19-59-8-32.

Full text

Abstract:

The work investigates the sulfonation mechanism of urea in oleum, which is used in the synthesis of sulfamic acid. In addition to sulfamic acid, carbon dioxide is also released in the process. The method of density functional theory was used to model the sulfonation reaction using cation HSO3+ as a true sulfonating agent. All elementary acts, intermediates, and transition states of the reaction are determined. Six possible complexes of urea and cation HSO3+ are identified, of which two are reactive, formed through the bonding of the nitrogen atom of urea and sulfur of the HSO3+. The most stable complex is formed through the bonding of the oxygen atom of urea and sulfur of the HSO3+, from the reactive complexes it is separated by an activation barrier of 149.86 kJ/mol, so its formation inactivates the starting reagents and their return to a reactive state is possible only through interaction with negatively charged particles. The activation energies and thermal effects of the stages are calculated. The first stable intermediate of the process is isocyanic acid. Subsequently, isocyanic acid reacts with sulfuric by two mechanisms: the formation of urethane-like structures of NH2COOSO3H or carbamic acid. The second mechanism is preferred since it requires much milder conditions. Using the continuum models D-PCM and COSMO, the influence of the solvent on the reaction mechanism was studied. As a solvent, 100% sulfuric acid was taken. The maximum activation energy of elementary stages according to the first mechanism was: 167.37 (COSMO) kJ/mol, 169.77 (D-PCM), without solvent 180.38 kJ/mol. By the second mechanism: 57.38 (COSMO) kJ/mol, 59.91 (D-PCM), without solvent 91.15 kJ/mol. The number of elementary acts is 6 for the first mechanism and 7 for the second.

APA, Harvard, Vancouver, ISO, and other styles

48

Maskaeva, Larisa N., Victoria M. Yurk, Anastasia V. Belceva, Ivan V. Zarubin, Anastasia D. Kutyavina, and Vyacheslav F. Markov. "Chemical bath synthesis of metal chalcogenide films. Part 42. Experimental verification of the deposition regions of PbSe by sodium selenosulfate and selenourea in the presence of various ligands." Butlerov Communications 60, no. 10 (October 31, 2019): 88–98. http://dx.doi.org/10.37952/roi-jbc-01/19-60-10-88.

Full text

Abstract:

Calculation of ionic equilibria in the reaction system for synthesis of PbSe thin films was carried out. Three reaction systems containing the following combinations of reagents were considered: sodium citrate with liquid ammonia and sodium selenosulfate (system 1) or selenourea (system 2) used as chalcogenizer, ethilendiamine, sodium acetate and selenourea (system 3).The main lead complex compoundsprevented the fast PbSe formation in system 1 and 2 in region of pH of intensive selenosulfate and selenourea decomposition were hydroxo-citrate complexes. In the system 3 complexes with ethilendiamine and acetate-ions played the most significant role. For evaluating the deposition conditions of the main and impurity phases (metal hydroxides and cyanamides) by thermodynamic calculations taking into account the sizes of critical nucleis, the boundary conditions and regions of formation of PbSe, Pb(OH)2, PbCN2 in the studied reaction systems were found. The calculation results are presented in the form of three-dimensional dependencies in the coordinates “indicator of the initial concentration of the metal salt – pH of the solution – ligand concentration” and “indicator of the initial concentration of the metal salt – pH of the solution – concentration of the chalcogenizer”. Based on the calculations and preliminary experiments, the compositions of the discussed reaction mixtures were formed for the chemical bath deposition of PbSe films, which, in addition to the main components, included a dopant in the form of ammonium iodide. In the synthesis process at a temperature of 353 K (system 1 and 2) for 60 minutes and 308 K for 90 minutes (system 3), using all the studied reaction systems on glass substrates, homogeneous PbSe layers with a thickness of ~500 to ~700 nm were obtained. The ratio between the main elements of Pb and Se in the film varies between 0.98-1.32, and the iodine content is 7-11 at.% depending on the composition of the reaction bath.

APA, Harvard, Vancouver, ISO, and other styles

49

Coin-Carvalho, João Eduardo, and Vera Helena Ostronoff. "Cuidado e transformação social: avaliação da implantação do plantão comunitário no Complexo da Funerária." Estudos de Psicologia (Natal) 19, no. 2 (June 2014): 138–44. http://dx.doi.org/10.1590/s1413-294x2014000200006.

Full text

Abstract:

A prática em Psicologia Social Comunitária solicita a instituição de ferramentas ajustadas às condições concretas de intervenção. Neste trabalho são discutidas ações psicossociais em uma comunidade de baixa renda de São Paulo realizadas a partir de um dispositivo de atendimento em grupo. Durante os anos de 2007 e 2008 foram conduzidos Plantões Comunitários, um grupo aberto e de participação espontânea tendo como referências a prática do Plantão Psicológico e os princípios teórico-políticos da Psicologia Social Comunitária. Em uma "roda de cadeiras" montada sobre a calçada, três psicólogos mediaram encontros semanais entre moradores. O Plantão Comunitário permitiu o acolhimento e o compartilhamento de experiências, assim como promoveu horizontalidade e empoderamento entre os participantes. Os resultados indicam a importância de dispositivos simples de encontro, desafiando os limites entre o público e o privado e justifica o desenvolvimento de práticas grupais inovadoras e críticas para ações psicossociais.

APA, Harvard, Vancouver, ISO, and other styles

50

Kutlugildina, Galia G., Zalia F. Ramazanova, and Yury S. Zimin. "Physico-chemical interaction patterns of oxidized polyvinyl alcohol fraction with 4- and 5-aminosalicylic acids." Butlerov Communications 58, no. 4 (April 30, 2019): 77–84. http://dx.doi.org/10.37952/roi-jbc-01/19-58-4-77.

Full text

Abstract:

The interaction of the oxidized fraction of polyvinyl alcohol (OF of PVA) with 4- and 5-aminosalicylic acids (4- and 5-ASA) in aqueous solutions was examined by ultraviolet spectroscopy. OF of PVA is obtained by oxidation of polyvinyl alcohol in an aqueous medium affected by hydrogen peroxide (363 K, [PVA] = 3.5% wt., [H2O2] = 1 mol/l, toxid. = 45 min), further separated from the solution by acetone addition. The average molecular weight of the oxidized fraction of PVA, calculated from the experimentally found value of the characteristic viscosity using the Mark-Kun-Houwink equation, amounted to 4.5 kDa. It was found that the addition of the original (non-oxidized) polyvinyl alcohol to aqueous solutions of 4- and 5-ASA does not change their UV spectra. At the same time, the introduction of an oxidized fraction of polyvinyl alcohol into aqueous solutions of aminosalicylic acids leads to spectral changes, indicating intermolecular interactions and complexation. By the method of molar ratios, it was shown that in dilute aqueous solutions OF of PVA forms complex 1 : 1 compounds with 4-ASA and 5-ASA, i.e., one molecule of 4- or 5-aminosalicylic acid accounts for one carboxyl group of the oxidized PVA fraction. Using this method, in the 291-316 K temperature range, the stability constants (K) of the resulting complex compounds were calculated. The results analised demonstrated that the oxidized fraction of polyvinyl alcohol forms strong enough complexes with 4- and 5-aminosalicylic acids: the K values in the temperature range under study vary within (1-7)∙104 l/mol. It was found out that with increasing temperature, the values of stability constants of complex compounds decrease. The study of the temperature dependence of K made it possible to determine the standard values of the changes in the Gibbs energy (ΔG°), enthalpy (ΔH°), and entropy (ΔS°) of complexing. Negative values of thermodynamic parameters indicate a spontaneous process of formation of complexes, their exothermicity and the resulting constraints of the movements of molecules.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Complexos de rodi'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles