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Articoli di riviste sul tema "Polymorphic"

Autore: Grafiati

Pubblicato: 4 giugno 2021

Ultima modifica: 25 luglio 2025

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1

G, Nithya, Sudha R, and Charles C. Kanakam. "Polymorphic behavior of an organic compound." Asian Journal of Pharmaceutical and Clinical Research 10, no. 4 (2017): 259. http://dx.doi.org/10.22159/ajpcr.2017.v10i4.16702.

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Objective: Polymorphic crystals were exhibited in many organic compounds. The frequency changes, relative intensities, band contours, and numberof bands were observed in the spectra of different polymorphism which may be due to molecule-molecule interactions in the crystal unit cells. Theshape of a molecule at its site in the unit cell is distorted by molecular interactions.Methods: The identification of a pure crystal form and to quantify a mixture of two forms infrared and Raman spectra of different crystalline formsof the same organic compound can be used. 2’-chloro-4-methoxy-3-nitro benzil

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Ângelo, Marilene, Jennifer Jacon, Olimpia Maria Santos, et al. "Occurrence of polymorphism in famotidine raw materials." Acta Crystallographica Section A Foundations and Advances 70, a1 (2014): C1563. http://dx.doi.org/10.1107/s2053273314084368.

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Polymorphs are compounds with the same chemical composition, however the molecules are arranged in at least two different ways in the solid state. Famotidine is a histamine H2-receptor antagonist inhibitor of gastric secretion and widely used in gastric and duodenal ulcer disease. Two polymorphs are described for famotidine, A and B. The polymorph A is the most thermodynamically stable form and polymorph B is the kinetically favored form being marketed because it presents greater pharmacological activity. The aim of this study was to evaluate the occurrence of famotidine polymorphs in five raw

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3

So, Hee-Soo, and Shinya Matsumoto. "Three differently coloured polymorphs of 3,6-bis(4-chlorophenyl)-2,5-dipropyl-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione." Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials 75, no. 3 (2019): 414–22. http://dx.doi.org/10.1107/s2052520619004773.

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In this paper, the conformational polymorphism of a chlorinated diketopyrrolopyrrole (DPP) dye having flexible substituents in a non-hydrogen-bonding system is reported. The propyl-substituted DPP derivative (PR3C) has three polymorphic forms, each showing a different colour (red, orange and yellow). All polymorphs could be obtained concomitantly under various crystallization conditions. The results of the crystal structure analysis indicate that PR3C adopts different conformations in each polymorph. The packing effect caused by the difference in the arrangement of neighbouring molecules was f

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4

Akune, Yoko, Risa Hirosawa, Atsushi Koseki, and Shinya Matsumoto. "Role of halogen substituents in a series of polymorphic 2,5-diamino-3,6-dicyanopyrazine derivatives with highly flexible groups." Zeitschrift für Kristallographie - Crystalline Materials 232, no. 5 (2017): 395–405. http://dx.doi.org/10.1515/zkri-2016-2007.

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AbstractThe crystal structures of the ortho-X-benzyl derivatives, where X=F, Cl, Br, I, and Me, of 2,5-bis(N,N-dibenzylamino)-3,6-dicyanopyrazine dyes (C34H24N6X4) were analysed to evaluate the effect of a systematic series of structures on the occurrence of polymorphism. Detailed crystal structure analysis indicated that the thermally stable forms of the polymorphic derivatives (Cl and Br derivatives) were close-packed, whereas those of the non-polymorphic derivatives (F and I derivatives) were stabilised by an intermolecular interaction involving the ortho-substituents. In the thermally meta

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5

Cieślińska, Karolina, Brygida Manikowska-Ślepowrońska, and Dariusz Jakubas. "Color Polymorphism of Unfeathered Parts of the Great White Egret Ardea alba alba in Europe: An Analysis of the Internet Images." Diversity 15, no. 10 (2023): 1063. http://dx.doi.org/10.3390/d15101063.

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Polymorphism has been described in many avian taxa including Ardeidae. This study investigated the spatio-temporal distribution of color polymorphic forms (with regard to the color of the unfeathered parts (legs/lores)) of the Great White Egret Ardea alba alba in internet images from Europe. In total, 140 images of presumed polymorphs from 16 countries (from 2006 to 2021) have been collected and examined. Eight coloration schemes of visible unfeathered parts were distinguished. Since some polymorphs may represent the subspecies Eastern Great Egret Ardea alba modesta, the ratio of beak length t

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6

Wantha, Lek. "Kinetics of the Solution-Mediated Polymorphic Transformation of Organic Compounds." Current Pharmaceutical Design 24, no. 21 (2018): 2383–93. http://dx.doi.org/10.2174/1381612824666180601093228.

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Polymorphism is a behavior of a substance to crystallize into more than one district crystal structures. Preferential formation of a polymorph depends strongly on the kinetics of the relevant mechanisms. Solutionmediated polymorphic transformation is an important mechanism in crystallization of organic compounds from solution. Knowing its kinetics allows us to understand the process and control the polymorphic formation. In this review, concepts, kinetics, and process modeling of crystallization and solution-mediated polymorphic transformation are examined and summarized.

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7

Hsu, Cheng-Hung, Wen-Ting Ke, and Shan-Yang Lin. "Progressive Steps of Polymorphic Transformation of Gabapentin Polymorphs Studied by Hot-stage FTIR Microspectroscopy." Journal of Pharmacy & Pharmaceutical Sciences 13, no. 1 (2010): 67. http://dx.doi.org/10.18433/j3fs32.

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Purpose. The aim of this study was to determine the progressive processes of polymorphic transformation of different gabapentin (GBP) polymorphs by using hot-stage Fourier transform infrared (FTIR) microspectroscopy. Methods. Four polymorphs of GBP were previously prepared and then identified by differential scanning calorimetry (DSC), thermogravimetric (TG) analysis, FTIR microspectroscopy and X-ray powder diffractometry. A novel hot-stage FTIR microspectroscopic technique was used to investigate the progressive steps of polymorphic transformation of each GBP polymorph sealed within two piece

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8

Goossens, D. J., and E. J. Chan. "Synchrotron X-ray diffuse scattering from a stable polymorphic material: terephthalic acid, C8H6O4." Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials 73, no. 1 (2017): 112–21. http://dx.doi.org/10.1107/s2052520616018801.

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Terephthalic acid (TPA, C8H6O4) is an industrially important chemical, one that shows polymorphism and disorder. Three polymorphs are known, two triclinic [(I) and (II)] and one monoclinic (III). Of the two triclinic polymorphs, (II) has been shown to be more stable in ambient conditions. This paper presents models of the local order of polymorphs (I) and (II), and compares the single-crystal diffuse scattering (SCDS) computed from the models with that observed from real crystals. TPA shows relatively weak and less-structured diffuse scattering than some other polymorphic materials, but it doe

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9

Kuzmin, V. S., V. V. Chernyshev, and A. I. Luttseva. "X-RAY POWDER DIFFRACTION IN QUALITY CONTROL OF MEDICINES." Bulletin of the Scientific Centre for Expert Evaluation of Medicinal Products 8, no. 3 (2018): 158–61. http://dx.doi.org/10.30895/1991-2919-2018-8-3-158-161.

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X-ray powder diffraction is one of the methods used for detection and analysis of polymorphic forms of pharmaceutical substances. The article elucidates the concept of polymorphism, briefly explains physical characteristics of this phenomenon, conditions of polymorphic transformations and the prevalence of polymorphic forms among drug substances. It should be noted that polymorphism is observed in drug substances belonging to different pharmacologic classes. Polymorphic forms of the same drug substance have different solubility, melting point, resistance to oxidation and to other destructive p

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10

Wójcik, Grażyna, and Izabela Mossakowska. "Polymorphs of p-nitrophenol as studied by variable-temperature X-ray diffraction and calorimetry: comparison with m-nitrophenol." Acta Crystallographica Section B Structural Science 62, no. 1 (2006): 143–52. http://dx.doi.org/10.1107/s010876810503418x.

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Crystal structures of two polymorphic forms of p-nitrophenol have been determined at several temperatures between 120 and 375 K. The thermal expansion tensor has been determined for both polymorphs. The rigid-body mean-square amplitudes of molecular translations and librations and the amplitudes of the internal torsions of the nitro group have been calculated at different temperatures. Differential scanning calorimetry was used to find the temperature and enthalpy of the polymorphic transformation. The results were compared with those recently obtained for m-nitrophenol polymorphs. Some conclu

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11

Wardhana, Yoga Windhu, Risanteni Riskasari, and Fikri Alatas. "Phase Transitions Among of Valsartan Polymorphs due to Grinding and Humidity Variations." Indonesian Journal of Pharmaceutics 3, no. 2 (2021): 82. http://dx.doi.org/10.24198/idjp.v3i2.35312.

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Phase transition between drugs with polymorphisms needs attention due to unconscious changes in quality. Valsartan (VAL) is a drug model with polymorphic events to be studied here. Two polymorphic forms were obtained from recrystallization with various organic solvents such as acetonitrile and n-butyl acetate. With untreated materials (from the market) were used as a comparison in this study. The phase transition of each polymorph was studied through grinding and humidity variations (RH 75% and 98%) treatment. The polymorph characterization was observed by microscope light polarization (PLM),

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12

DELGADO, G., M. GUILLEN, and A. J. MORA. "4-METHYL HYPPURIC ACID: A CASE OF POLYMORPHISM AND SOLVATOMORPHISM." Periódico Tchê Química 16, no. 32 (2019): 812–19. http://dx.doi.org/10.52571/ptq.v16.n32.2019.830_periodico32_pgs_812_819.pdf.

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Polymorphism is known as the ability of a solid material to exist in more than one form or crystal structure, with important applications in the preparation of active pharmaceutical ingredients. Characterization of different polymorphs of the specific metabolite of 4-xylene can contribute to the chemical and pharmaceutical industry. Polymorphism is of particular importance in industrial processes, where different physical properties of polymorphic forms can substantially alter the viability and quality of a manufactured product. This is particularly so for the design and production of drugs in

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13

Khoj, Manal A., Colan E. Hughes, Kenneth D. M. Harris, and Benson M. Kariuki. "Polymorphic phase transformations of 3-chloro-trans-cinnamic acid and its solid solution with 3-bromo-trans-cinnamic acid." Acta Crystallographica Section C Structural Chemistry 74, no. 8 (2018): 923–28. http://dx.doi.org/10.1107/s2053229618009269.

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We have investigated the polymorphic phase transformations above ambient temperature for 3-chloro-trans-cinnamic acid (3-ClCA, C9H7ClO2) and a solid solution of 3-ClCA and 3-bromo-trans-cinnamic acid (3-BrCA, C9H7BrO2). At 413 K, the γ polymorph of 3-ClCA transforms to the β polymorph. Interestingly, the structure of the β polymorph of 3-ClCA obtained in this transformation is different from the structure of the β polymorph of 3-BrCA obtained in the corresponding polymorphic transformation from the γ polymorph of 3-BrCA, even though the γ polymorphs of 3-ClCA and 3-BrCA are isostructural. We a

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14

Pogoda, Dorota, Jan Janczak, and Veneta Videnova-Adrabinska. "New polymorphs of an old drug: conformational and synthon polymorphism of 5-nitrofurazone." Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials 72, no. 2 (2016): 263–73. http://dx.doi.org/10.1107/s2052520615024956.

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Two new polymorphic forms of 5-nitrofurazone (5-nitro-2-furaldehyde semicarbazone) have been synthesized and structurally characterized by single-crystal and powder X-ray diffraction methods, vibrational spectroscopy (FT–IR and temperature Raman), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and Hirshfeld surface analysis. The compound crystallizes in three different polymorphic formsP21/a(polymorph α),P21(polymorph β) andP21/c(polymorph γ), the crystal structures of two of which (polymorphs β and γ) represent new structure determinations. The solid-state molecular

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15

Rumel, Dey, and Roy Chowdhury Dona. "Review of Pharmaceutical Solid Polymorphism: Preparation, Characterization and Influence on Performance of Drugs." Journal of Advances in Bio- pharmaceutics and Pharmacovigilance 2, no. 1 (2020): 33–48. https://doi.org/10.5281/zenodo.3668629.

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<em>When the crystalline structure of the same chemical compound (and atomic formula) exhibits two or more patterns of the repeated unit cells, these crystalline structures are called polymorphs and the phenomena is referred to as polymorphism. Active pharmaceutical ingredient (API) can have a variety of polymorph. These different Polymorphic forms of drug substance exhibits different physical and chemical properties, including melting point, chemical reactivity, apparent solubility, dissolution rate, optical and mechanical properties, vapor pressure and density. Polymorphism properties of API

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16

Acebedo-Martínez, Francisco Javier, Carolina Alarcón-Payer, Antonio Frontera, et al. "Novel Polymorphic Cocrystals of the Non-Steroidal Anti-Inflammatory Drug Niflumic Acid: Expanding the Pharmaceutical Landscape." Pharmaceutics 13, no. 12 (2021): 2140. http://dx.doi.org/10.3390/pharmaceutics13122140.

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Any time the pharmaceutical industry develops a new drug, potential polymorphic events must be thoroughly described, because in a crystalline pharmaceutical solid, different arrangements of the same active pharmaceutical ingredient can yield to very different physicochemical properties that might be crucial for its efficacy, such as dissolution, solubility, or stability. Polymorphism in cocrystal formulation cannot be neglected, either. In this work, two different cocrystal polymorphs of the non-steroidal anti-inflammatory drug niflumic acid and caffeine are reported. They have been synthesize

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17

Du, Dan, Guo-Bin Ren, Ming-Hui Qi, Zhong Li, and Xiao-Yong Xu. "Solvent-Mediated Polymorphic Transformation of Famoxadone from Form II to Form I in Several Mixed Solvent Systems." Crystals 9, no. 3 (2019): 161. http://dx.doi.org/10.3390/cryst9030161.

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This paper discloses six polymorphs of famoxadone obtained from polymorph screening, which were characterized by XRPD, DSC, and SEM. A study of solvent-mediated polymorphic transformation (SMPT) of famoxadone from the metastable Form II to the stable Form I in several mixed solvent systems at the temperature of 30 °C was also conducted. The transformation process was monitored by Process Analytical Technologies. It was confirmed that the Form II to Form I polymorphic transformation is controlled by the Form I growth process. The transformation rate constants depended linearly on the solubility

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18

Aramini, Andrea, Gianluca Bianchini, Samuele Lillini, et al. "Unexpected Salt/Cocrystal Polymorphism of the Ketoprofen–Lysine System: Discovery of a New Ketoprofen–l-Lysine Salt Polymorph with Different Physicochemical and Pharmacokinetic Properties." Pharmaceuticals 14, no. 6 (2021): 555. http://dx.doi.org/10.3390/ph14060555.

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Ketoprofen–l-lysine salt (KLS) is a widely used nonsteroidal anti-inflammatory drug. Here, we studied deeply the solid-state characteristics of KLS to possibly identify new polymorphic drugs. Conducting a polymorph screening study and combining conventional techniques with solid-state nuclear magnetic resonance, we identified, for the first time, a salt/cocrystal polymorphism of the ketoprofen (KET)–lysine (LYS) system, with the cocrystal, KET–LYS polymorph 1 (P1), being representative of commercial KLS, and the salt, KET–LYS polymorph 2 (P2), being a new polymorphic form of KLS. Interestingly

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Horvath, Ulrike E. I., and Helgard G. Raubenheimer. "A third polymorph of (2-thiazolidinethionato)(triphenylphosphine)gold(I)." Acta Crystallographica Section E Structure Reports Online 62, no. 7 (2006): m1644—m1645. http://dx.doi.org/10.1107/s1600536806023178.

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The title compound, [Au(C3H4NS2)(C18H15P)], is a third polymorphic form of a compound previously reported by Grant, Forward & Fackler Jr [Z. Kristallogr. (1996). 211, 483–484]. At 100 K, the present polymorph shows triclinic symmetry, as do the other two polymorphs.

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van den Ende, Joost, and Herma Cuppen. "Solid-to-solid polymorphic transitions in amino acid crystals." Acta Crystallographica Section A Foundations and Advances 70, a1 (2014): C1627. http://dx.doi.org/10.1107/s2053273314083727.

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The properties of crystals are related to their structure and therefore they can be different for different polymorphs. For example, the pharmaceutical characteristics bioavailability and shelf life can depend on the formed polymorph and its stability. We aim to understand transitions between polymorphs that occur in the solid phase, with the ultimate goal to induce or inhibit these transitions. We apply Molecular Dynamics (MD) simulations as a computational microscope to study these processes at the molecular level. Our used model systems for polymorphic behavior of molecular crystals in a ph

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Falk, Jacqueline, Detlef Hofmann, and Klaus Merz. "Controlled usage of H/D exchange to circumvent concomitant polymorphs of ROY." IUCrJ 5, no. 5 (2018): 569–73. http://dx.doi.org/10.1107/s2052252518009995.

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The hypothesis that H/D exchange affects the structural formation of organic compounds in the solid state is supported by a deeper understanding of the altering polymorphism of ROY (a substance striking for its high number of polymorphic forms) through deuteration. Therefore, ROY was deuterated at its amine function, which leads to a seemingly small yet effective modification of the hydrogen-bond strength. In contrast to the crystallization of the non-deuterated ROY in methanol or ethanol, which leads to the simultaneous formation of two forms (OP and Y polymorphs), so-called concomitant polym

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22

Masum, Zia Uddin, P. Grant Spoors, Matt D. Burke, and Vivek Gupta. "Novel Polymorphic Patterns for Elacestrant Dihydrochloride." Pharmaceutics 17, no. 6 (2025): 745. https://doi.org/10.3390/pharmaceutics17060745.

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Objective: This study expands on the polymorphic characterization of elacestrant dihydrochloride, developed by Stemline Therapeutics and approved by the FDA in 2023. The article focuses on more extensive polymorphism screening using various methods and solvents to discover the new polymorphism forms of this molecule, besides identifying three polymorphic forms in the previously published studies. Methods: The crystalline and amorphous elacestrant hydrochloride solubility was assessed, and crystals were formed, followed by polymorph screening using 40 non-conventional solvents via different tec

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23

Yang, Yuxin, Jia Liu, Anna Hu, Ting Nie, Zeneng Cheng, and Wenjie Liu. "A Critical Review on Engineering of d-Mannitol Crystals: Properties, Applications, and Polymorphic Control." Crystals 12, no. 8 (2022): 1080. http://dx.doi.org/10.3390/cryst12081080.

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d-mannitol is a common six-carbon sugar alcohol, which is widely used in food, chemical, pharmaceutical, and other industries. Polymorphism is defined as the ability of materials to crystallize into different crystal structures. It has been reported for a long time that d-mannitol has three polymorphs: β, δ, and α. These different polymorphs have unique physicochemical properties, thus affecting the industrial applications of d-mannitol. In this review, we firstly introduced the characteristics of different d-mannitol polymorphs, e.g., crystal structure, morphology, molecular conformational en

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24

Takeguchi, Seiya, Arisa Sato, Hironori Hondoh, Mio Aoki, Hidetaka Uehara та Satoru Ueno. "Multiple β Forms of Saturated Monoacid Triacylglycerol Crystals". Molecules 25, № 21 (2020): 5086. http://dx.doi.org/10.3390/molecules25215086.

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We have investigated the polymorphism of triacylglycerol (TAG) crystals as they affect the qualities such as shelf life, mouth feel, and texture of chocolate and other products. Saturated monoacid TAGs, like trilaurin, are considered as models for TAG crystallization; however, there is still debate about the number of their polymorphs that exist. In this study, we characterized a set of novel polymorphs, β forms of saturated monoacid TAGs, which were obtained via different pathways depending on the crystallization history, by polarized light microscopy, X-ray diffraction, and differential scan

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Tao, Yue, Yuhan Gao, Baoxi Zhang, et al. "Advances in Quantitative Analytical Methods for Solid Drugs." Crystals 15, no. 1 (2024): 38. https://doi.org/10.3390/cryst15010038.

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The solid form of the drug can directly affect the physicochemical properties, bioavailability, safety, and efficacy of the drug, and its types mainly include amorphous state, single-component polycrystalline, hydrate, solvate, salt, and cocrystal. Polymorphic drugs are solid drugs whose active ingredients exist in a specific crystalline state. Polymorphic drugs are solid drugs whose active ingredients exist in a specific crystalline state. Drug polymorphism refers to the presence of two or more different crystalline states of the drug. Pharmaceutical cocrystal is a new type of solid form that

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Rajendrakumar, Satyasree, Anuja Surampudi Venkata Sai Durga, Jagadeesh Babu Nanubolu, and Sridhar Balasubramanian. "Two novel polymorphic forms of iron-chelating agent deferiprone." Acta Crystallographica Section C Structural Chemistry 76, no. 2 (2020): 193–200. http://dx.doi.org/10.1107/s2053229620000959.

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Thalassemia is a genetic blood disorder requiring life-long blood transfusions. This process often results in iron overload and can be treated by an iron-chelating agent, like deferiprone (3-hydroxy-1,2-dimethylpyridin-4-one), C7H9NO2, in an oral formulation. The first crystal structure of deferiprone, (Ia), was reported in 1988 [Nelson et al. (1988). Can. J. Chem. 66, 123–131]. In the present study, two novel polymorphic forms, (Ib) and (Ic), of deferiprone were identified concomitantly with polymorph (Ia) during the crystallization experiments. Polymorph (Ia) was redetermined at low temperat

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Paczkowska, Magdalena, Gabriela Wiergowska, Andrzej Miklaszewski, et al. "The Analysis of the Physicochemical Properties of Benzocaine Polymorphs." Molecules 23, no. 7 (2018): 1737. http://dx.doi.org/10.3390/molecules23071737.

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The study was a pioneering attempt to assess the influence of the structural polymorphism (forms I, II, III) of benzocaine on its solubility, apparent solubility, and chemical stability, which are vital parameters for preformulation and formulation work. The impact of differences in the solubility of selected polymorphs of benzocaine on their permeability through artificial biological membranes (PAMPA system) was evaluated. The polymorphs of benzocaine were obtained by means of techniques commonly used for the preparation of various pharmaceutical dosage forms: ball milling, micro milling, and

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Hean, Duane, Andreas Lemmerer, and Joseph Michael. "Rampant Polymorphism in Pharmaceuticals: An Isoniazid Derivative." Acta Crystallographica Section A Foundations and Advances 70, a1 (2014): C653. http://dx.doi.org/10.1107/s2053273314093462.

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Investigations into the polymorphic forms of Active Pharmaceutical Ingredients (APIs) are of vital importance to drug formulations and are often kept a closely guarded secret by pharmaceutical companies. This secrecy is maintained as the nature of the polymorph could either make or break a drug formulation. Polymorphism is the ability of a solid crystalline form to exist in more than one structural arrangement. The variation in the crystalline forms often displays different mechanical, thermal, and chemical properties. These changes can remarkably influence the bioavailability, hygroscopicity,

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Shiau, Lie-Ding. "Modelling of the Polymorph Nucleation based on Classical Nucleation Theory." Crystals 9, no. 2 (2019): 69. http://dx.doi.org/10.3390/cryst9020069.

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To elucidate the relative nucleation rates of different polymorphs, a competitive kinetic model is developed based on classical nucleation theory to describe the time evolution of two different polymorphic cluster size distributions controlled by the association and dissociation of the solute molecules during polymorph nucleation. Although there is only one type of the solute molecules, the agglomerated solute clusters are divided into two types–A form and B form, which resemble the structures and morphologies of the different mature polymorphs and eventually lead to the formation of two polym

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Schmidtmann, Marc, Derek S. Middlemiss, and Chick C. Wilson. "Isotopomeric polymorphism in a “doubly-polymorphic” multi-component molecular crystal." CrystEngComm 17, no. 28 (2015): 5273–79. http://dx.doi.org/10.1039/c5ce00123d.

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Isotopomeric polymorphism is observed in complexes of isonicotinamide with oxalic acid, highly unusual here in that each isotopic complex is itself polymorphic, a situation of “double polymorphism”. The four polymorphic forms exhibit different degrees of hydron transfer.

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Chistyakov, Dmitry, and Gleb Sergeev. "The Polymorphism of Drugs: New Approaches to the Synthesis of Nanostructured Polymorphs." Pharmaceutics 12, no. 1 (2020): 34. http://dx.doi.org/10.3390/pharmaceutics12010034.

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Among the significant problems of modern pharmacology are the low solubility and bioavailability of drugs. One way to resolve this problem is to obtain new polymorphic forms of drugs with improved physicochemical properties. Various approaches have been developed with this aim, including the preparation of co-crystals, the use of nanoparticles, or the use of compounds in the form of a salt. A promising direction in pharmacology concerns the production of new stable polymorphic structures. In this mini-review, we consider certain aspects of drug polymorphism, methods for the synthesis of polymo

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Mnguni, Malitsatsi J., Joseph P. Michael, and Andreas Lemmerer. "Binary polymorphic cocrystals: an update on the available literature in the Cambridge Structural Database, including a new polymorph of the pharmaceutical 1:1 cocrystal theophylline–3,4-dihydroxybenzoic acid." Acta Crystallographica Section C Structural Chemistry 74, no. 6 (2018): 715–20. http://dx.doi.org/10.1107/s2053229618006861.

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An analysis and classification of the 2925 neutral binary organic cocrystals in the Cambridge Structural Database is reported, focusing specifically on those both showing polymorphism and containing an active pharmaceutical ingredient (API). The search was confined to molecules having only C, H, N, O, S and halogens atoms. It was found that 400 out of 2925 cocrystals can be classified as pharmaceutical cocrystals, containing at least one API, and that of those, 56 can be classified as being polymorphic cocrystals. In general, the total number of polymorphic cocrystal systems of any type stands

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Shankar C., Abida P. S., Jiji Joseph, Rose Mary Francies, Deepu Mathew, and Beena R. "Evaluation for Parental Polymorphism and Identification of Microsatellites Linked to Drought Tolerance in Rice (Oryza sativa L.)." International Journal of Plant & Soil Science 35, no. 22 (2023): 275–84. http://dx.doi.org/10.9734/ijpss/2023/v35i224134.

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Aims: To identify the ready-to-use polymorphic microsatellite markers associated with drought tolerance for marker-assisted backcross breeding through a polymorphism survey between Jyothi and Chuvannamodan rice varieties. Place and Duration of Study: Centre for plant biotechnology and molecular biology, Thrissur, Kerala, India, during January to May 2023. Methodology: The genomic DNA of Jyothi and Chuvannamodan was isolated by following CTAB (Cetyltrimethyl Ammonium Bromide) method with modification. Isolated DNA from both varieties was subjected to PCR amplification using 208 Simp

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34

Britton, Doyle, Victor G. Young, Wayland E. Noland, Matthew J. Pinnow, and Christopher M. Clark. "Four polymorphs (polytypes) of 5,6-dimethylbenzofurazan 1-oxide." Acta Crystallographica Section B Structural Science 68, no. 5 (2012): 536–42. http://dx.doi.org/10.1107/s0108768112037457.

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5,6-Dimethylbenzofurazan 1-oxide (Me2BF), C8H8N2O2, occurs in four polymorphic forms that are polytypes of each other. Each polymorph of Me2BF contains molecules disordered about pseudo-twofold axes and arranged head-to-tail in ribbons, with the ribbons forming approximately planar layers held together by weak C—H...N and C—H...O interactions. Adjacent layers interact in different ways in the different polymorphs. In addition to twinning in the individual polymorphs, four examples of allotwining, that is, oriented overgrowths between different polymorphs, were found.

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Modec, Barbara. "Polymorphism ofmer-μ-oxalato-bis[chloridotripyridinecobalt(II)] pyridine disolvate". Acta Crystallographica Section C Crystal Structure Communications 69, № 4 (2013): 340–43. http://dx.doi.org/10.1107/s010827011300499x.

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Single crystals of a triclinic polymorphic form ofmer-μ-oxalato-bis[chloridotripyridinecobalt(II)] pyridine disolvate, [Co2(C2O4)Cl2(C5H5N)6]·2C5H5N, have been prepared by solvothermal methods. The structure and geometric parameters strongly resemble those of the previously reported monoclinic polymorph [Bolte (2006).Acta Cryst.E62, m597–m598]. In both polymorphic forms, the dinuclear complex molecules are located on a crystallographic centre of inversion, with the CoIIcations in a distorted octahedral environment consisting of a chloride ligand, three pyridine ligands and a chelating bis-bide

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36

Mareczek, Lena, Carolin Riehl, Meike Harms, and Stephan Reichl. "Understanding the Multidimensional Effects of Polymorphism, Particle Size and Processing for D-Mannitol Powders." Pharmaceutics 14, no. 10 (2022): 2128. http://dx.doi.org/10.3390/pharmaceutics14102128.

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The relevance of the polymorphic form, particle size, and processing of mannitol for the mechanical properties of solid oral dosage forms was examined. Thus, particle and powder properties of spray granulated β D-mannitol, β D-mannitol, and δ D-mannitol were assessed in this study with regards to their manufacturability. D-mannitol is a commonly used excipient in pharmaceutical formulations, especially in oral solid dosage forms, and can be crystallized as three polymorphic forms, of which β is the thermodynamically most stable form and δ is a kinetically stabilized polymorph. A systematic ana

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37

Guzmán-Ornelas, Milton-Omar, Marcelo Heron Petri, Mónica Vázquez-Del Mercado, et al. "CCL2 Serum Levels and Adiposity Are Associated with the Polymorphic Phenotypes -2518A on CCL2 and 64ILE on CCR2 in a Mexican Population with Insulin Resistance." Journal of Diabetes Research 2016 (2016): 1–11. http://dx.doi.org/10.1155/2016/5675739.

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Abstract (sommario):

Genetic susceptibility has been described in insulin resistance (IR). Chemokine (C-C motif) ligand-2 (CCL2) is overexpressed in white adipose tissue and is the ligand of C-C motif receptor-2 (CCR2). TheCCL2G-2518A polymorphism is known to regulate gene expression, whereas the physiological effects of theCCR2Val64Ile polymorphism are unknown. The aim of the study is to investigate the relationship between these polymorphisms with soluble CCL2 levels (sCCL2), metabolic markers, and adiposity. In a cross-sectional study we included 380 Mexican-Mestizo individuals, classified with IR according to

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38

Myz, Svetlana A., Anatoly A. Politov, Svetlana A. Kuznetsova, and Tatyana P. Shakhtshneider. "Morphological Changes in Betulin Particles as a Result of Polymorphic Transformations, and Formation of Co-Crystals under Heating." Powders 2, no. 2 (2023): 432–44. http://dx.doi.org/10.3390/powders2020026.

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Changes in the morphology of betulin crystals during heating at selected temperatures corresponding to polymorphic transformations were investigated. It was shown that the prismatic crystals of starting betulin form III were converted into needles at 120 °C after water removal, followed by the III→II polymorphic transformation. During further heating up to 180 °C, the whiskers of betulin form I were grown. Experiments on betulin heating in the presence of dicarboxylic acids, adipic or suberic showed that the morphological changes can serve as a test for the formation of cocrystals. According t

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39

An, Ji-Hun, Wonno Youn, Alice Kiyonga, et al. "Kinetics of the Solution-Mediated Polymorphic Transformation of the Novel l-Carnitine Orotate Polymorph, Form-II." Pharmaceutics 10, no. 4 (2018): 171. http://dx.doi.org/10.3390/pharmaceutics10040171.

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Research studies related to the polymorphs of l-Carnitine orotate (CO), a medication used for the treatment and prevention of liver diseases, are insignificant or almost nonexistent. Accordingly, in the present study, l-Carnitine orotate (CO) was prepared for investigating CO polymorphs. Here, a reactive crystallization was induced by reacting 1g of l-Carn (1 equivalent) and 0.97 g of OA (1 equivalent) in methanol (MeOH); as a result, CO form-I and CO form-II polymorphs were obtained after 1 h and 16 h of stirring, respectively. The characterization of CO polymorphs was carried out utilizing P

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40

Mapp, Lucy, Mateusz Pitak, Simon Coles, and Srinivasulu Aitipamula. "Charge density studies on 1:1 co-crystals of ethenzamide and saccharin." Acta Crystallographica Section A Foundations and Advances 70, a1 (2014): C964. http://dx.doi.org/10.1107/s2053273314090354.

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Abstract (sommario):

The study of multi-component crystals, as well as the phenomenon of polymorphism, both have relevance to crystal engineering. Obtaining a specific polymorph is crucial as different polymorphs usually exhibit different physical and chemical properties and often the origin of this behaviour is unknown. This is especially important in the pharmaceutical industry. Herein, we present results of comparative studies of an analgesic drug, ethenzamide and its co-crystals with saccharin. The co-crystalisation of ethenzamide (2-ethoxybenzamide, EA) with saccharin (1,1-dioxo-,1,2-benzothiazol-3-one, SAC)

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41

Jurek, Paul, Garry E. Kiefer, and Frank R. Fronczek. "Crystal structures of two polymorphic forms of DOTAM-mono-acid dihydrate." Acta Crystallographica Section C Structural Chemistry 74, no. 5 (2018): 542–47. http://dx.doi.org/10.1107/s2053229618004631.

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Abstract (sommario):

The structural chemistry of 2-[4,7,10-tris(carbamoylmethyl)-1,4,7,10-tetraazacyclododecan-1-yl]acetic acid dihydrate, C16H31N7O5·2H2O, is described. The macrocyclic compound, also known by the abbreviation DOTAM-mono-acid, crystallized at room temperature and was isolated concomitantly as two polymorphic forms. The structures of both polymorphs were determined at 90 K. The first polymorph crystallized as a zwitterionic dihydrate [systematic name: 4,7,10-tris(carbamoylmethyl)-1-(carboxylatomethyl)-1,4,7,10-tetraazacyclododecan-1-ium dihydrate] in the space group P21/n, with Z′ = 1. The second p

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42

Guzzi, A. F., F. S. L. Oliveira, M. M. S. Amaro, P. F. Tavares-Filho, and J. E. Gabriel. "In silico prediction of the functional and structural consequences of the non-synonymous single nucleotide polymorphism A122V in bovine CXC chemokine receptor type 1." Brazilian Journal of Biology 80, no. 1 (2020): 39–46. http://dx.doi.org/10.1590/1519-6984.188655.

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Abstract (sommario):

Abstract The current study aimed to assess whether the A122V causal polymorphism promotes alterations in the functional and structural proprieties of the CXC chemokine receptor type 1 protein (CXCR1) of cattle Bos taurus by in silico analyses. Two amino acid sequences of bovine CXCR1 was selected from database UniProtKB/Swiss-Prot: a) non-polymorphic sequence (A7KWG0) with alanine (A) at position 122, and b) polymorphic sequence harboring the A122V polymorphism, substituting alanine by valine (V) at same position. CXCR1 sequences were submitted as input to different Bioinformatics’ tools to ex

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43

CRARY, KARL, STEPHANIE WEIRICH, and GREG MORRISETT. "Intensional polymorphism in type-erasure semantics." Journal of Functional Programming 12, no. 6 (2002): 567–600. http://dx.doi.org/10.1017/s0956796801004282.

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Abstract (sommario):

Intensional polymorphism, the ability to dispatch to different routines based on types at run time, enables a variety of advanced implementation techniques for polymorphic languages, including tag-free garbage collection, unboxed function arguments, polymorphic marshalling and attened data structures. To date, languages that support intensional polymorphism have required a type-passing (as opposed to type-erasure) interpretation where types are constructed and passed to polymorphic functions at run time. Unfortunately, type-passing suffers from a number of drawbacks: it requires duplication of

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44

Subramanian, V., S. Gurtu, R. C. Nageswara Rao, and S. N. Nigam. "Identification of DNA polymorphism in cultivated groundnut using random amplified polymorphic DNA (RAPD) assay." Genome 43, no. 4 (2000): 656–60. http://dx.doi.org/10.1139/g00-034.

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Abstract (sommario):

Construction of a genetic linkage map is necessary to apply marker-assisted selection tools in a crop improvement program. Except for the recent studies from two laboratories, most of the previous studies have shown little or no DNA polymorphism in cultivated groundnut (Arachis hypogaea L.). In the present study, 70 selected genotypes, representing variability for several morphological, physiological, and other characters, were studied for polymorphism employing random amplified polymorphic DNA (RAPD) assay with 48 oligonucleotide primers. Of the 48 oligonucleotide primers only 7 (14.6%) yield

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45

Shishkina, Svitlana V., Anna M. Shaposhnyk, Vyacheslav N. Baumer, Natali I. Voloshchuk, Pavlo S. Bondarenko та Igor V. Ukrainets. "1-Allyl-4-hydroxy-2,2-dioxo-N-(4-methoxyphenyl)-1H-2λ⁶,1-benzothiazine-3-carboxamide: polymorphic transition due to grinding with the loss of the biological activity". Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials 78, № 1 (2022): 70–79. http://dx.doi.org/10.1107/s2052520621013093.

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Abstract (sommario):

A study of two polymorphic forms of 1-allyl-4-hydroxy-2,2-dioxo-N-(4-methoxyphenyl)-1-2λ6,1-benzothiazine-3-carboxamide (a structural analogue of piroxicam) has revealed some regularities in the crystal structure formation due to different evaporation rates from the tested solvents. The monoclinic polymorph crystallized from ethyl acetate is formed due to a large number of very weak C—H...O and C—H...π interactions as well as one strong stacking interaction. The triclinic polymorph crystallized from N,N-dimethylformamide is formed due to a small number of weak specific interactions and a maxim

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46

Mohan, Shikhar, Yi Li, Kevin Chu, et al. "Developing In Situ Chemometric Models with Raman Spectroscopy for Monitoring an API Disproportionation with a Complex Polymorphic Landscape." Pharmaceuticals 16, no. 2 (2023): 327. http://dx.doi.org/10.3390/ph16020327.

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Abstract (sommario):

An in situ Raman method was developed to characterize the disproportionation of two salts involving a complex polymorphic landscape comprising up to two metastable and one stable freebase forms. Few precedents exist for Raman calibration procedures for solid form quantitation involving more than two polymorphs, while no literature examples were found for cases with multiple metastable forms. Therefore, a new Raman calibration procedure was proposed by directly using disproportionation experiments to generate multiple calibration samples encompassing a range of polymorph ratios through in-line

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47

Sun, Mengying, Xiurong Hu, Xinbo Zhou, and Jianming Gu. "Determination of minor quantities of linezolid polymorphs in a drug substance and tablet formulation by powder X-ray diffraction technique." Powder Diffraction 32, no. 2 (2017): 78–85. http://dx.doi.org/10.1017/s0885715617000069.

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Abstract (sommario):

Linezolid (LZD) is one of the first commercially available synthetic oxazolidinone antibiotics and is widely used for the treatment of multidrug-resistant Gram-positive bacterial infection. LZD was found to have five polymorphic forms. The most stable and commercialized polymorphs are known as forms II and IV. Trace content of form II in LZD form IV will cause to transition LZD form IV to II rapidly. Powder X-ray diffraction (PXRD) methods were evaluated for the determination of the polymorphic content of the drug substance and drug product. The estimated limit of detection values of the singl

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48

Kinelovskii S.A. "Similarity between shock-induced polymorphic transitions in the silica system." Technical Physics 92, no. 6 (2022): 695. http://dx.doi.org/10.21883/tp.2022.06.54415.320-21.

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Abstract (sommario):

A set of experimental data on the thermodynamic parameters of polymorphic transitions in the silica system is considered. Analysis of these parameters in dimensionless form is performed. A fundamental result of the analysis is that the thermodynamic parameters of all silica polymorphs after transitions are described by a single universal Hugoniot of polymorphic transition. It is shown that the two-shock model of polymorphic transformations proposed earlier by the author describes all the results obtained in the analysis. A joint consideration of the experimental data and model calculations lea

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Кинеловский, С. А. "Подобие ударно-волновых полиморфных переходов в системе кремнезема". Журнал технической физики 92, № 6 (2022): 822. http://dx.doi.org/10.21883/jtf.2022.06.52511.320-21.

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Abstract (sommario):

A set of experimental data on the thermodynamic parameters of polymorphic transitions in the silica system is considered. Analysis of these parameters in dimensionless form is performed. A fundamental result of the analysis is that the thermodynamic parameters of all silica polymorphs after transitions are described by a single universal Hugoniot of polymorphic transition. It is shown that the two-shock model of polymorphic transformations proposed earlier by the author describes all the results obtained in the analysis. A joint consideration of the experimental data and model calculations lea

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50

Tian, Ruizheng, Cunhuan Zhang, Yixiao Huang, Xin Guo, and Maohua Chen. "A Novel Software and Method for the Efficient Development of Polymorphic SSR Loci Based on Transcriptome Data." Genes 10, no. 11 (2019): 917. http://dx.doi.org/10.3390/genes10110917.

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Abstract (sommario):

Traditional methods for developing polymorphic microsatellite loci without reference sequences are time-consuming and labor-intensive, and the polymorphisms of simple sequence repeat (SSR) loci developed from expressed sequence tag (EST) databases are generally poor. To address this issue, in this study, we developed a new software (PSSRdt) and established an effective method for directly obtaining polymorphism details of SSR loci by analyzing diverse transcriptome data. The new method includes three steps, raw data processing, PSSRdt application, and loci extraction and verification. To test

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