Each primer contained three tribution along the rice genome in order to evaluate the selective nucleotides at the 3' end. The core sequences of selective amplification primers were from Zabeau and Vos Two Pstl efficiency of this marker technology for use in marker- and ten Msel selective primers were synthesized. The Twenty primer combinations could be derived from these 12 range of polymorphic bands was from 4 to 21 mean of selective amplification primers. AFLP markers were generated in The level of polymorphism for 0.
The selective amplification profile was 1 ranging from A total of 22 codominant marker pairs was observed for all primer For the AFLP markers, the overall frequency of the combinations.
This ratio is the same as that of mix during the selective amplification step, a number of RFLP markers segregating in the same population doublets occurred and was determined for each primer Huang et al. Of the AFLP markers, 45 combination.
Only 28 doublets out of markers The markers in the boxes are RFLP markers. Map distances in centiMorgans cM are given on the left mosomes Table 2, Fig. The map length of rice increased from order on the combined map. The correlation between cM Huang et al. Map length cM length cM length cM no. The extension of the map towards telomeric markers were located adjacent to each other Fig. The most typical quarter of the increased map distance.
The remaining example is on chromosome Half of the chromosome three-quarters was due to a stretching effect, which was was covered by AFLP markers while the other half pronounced on most of the chromosomes Table 2. The mapping which has also been observed in other crops Becker of these AFLP markers had a stretching effect which et al. The small population size used in this study was very pronounced on most of the chromosomes may be one of the reasons, as it would offer comparative- Fig.
This is why we felt it timely to look into the historical development of its definition and to delimit it. A short introduction to thermodynamic aspects and characterization methods of polymorphs is given. One chapter is then dedicated to polymorphism of… Expand. View PDF. Save to Library Save. Create Alert Alert. Share This Paper.
Figures and Tables from this paper. Citation Type. Has PDF. Publication Type. More Filters. Acta crystallographica. Section C, Structural chemistry. View 1 excerpt, cites background. The phase evolution of pyrite NiS 2 and polymorphism of NiSe 2 have briefly been studied in the literature, but there has been limited work focusing on the phase transformations within each of these two systems.
Each reaction can be controlled by fine-tuning the reaction parameters, including temperature, time, and the precursor identity and concentration. Interestingly, both NiS 2 and NiSe 2 nanopyrites are active catalysts in the selective reduction of nitrobenzene to aniline, in agreement with other catalysts containing an fcc sub lattice.
Our results demonstrate a feasible, logical process for synthesizing nanocrystalline pyrites without common byproducts or impurities. This work can help in solving a major problem suspected in preventing pyrite FeS 2 and similar materials from large-scale use: the presence of small amounts of secondary phases and impurities.
Such files may be downloaded by article for research use if there is a public use license linked to the relevant article, that license may permit other uses. More by Marquix A. More by Philip Yox. Need an account? Click here to sign up. Download Free PDF. Polymorphism in Pharmaceutical Compounds. Poonam Tandon. A short summary of this paper.
Download Download PDF. Translate PDF. We have also discussed the importance of this phenomenon in pharmaceutical compounds and why is it necessary to study polymorphism. Keywords: Polymorphism, enantiotropes, monotropes, pharmaceutical compunds.
It is the ability of a substance to exist as two or more crystalline phases that have different arrangements or conformations of the molecules in the crystal lattice. The complete morphology of a material is described by polymorphism and other variables such as crystal habit, amorphous or crystallographic defects. Polymorphism is relevant to the fields of pharmaceuticals, agrochemicals, pigments and explosives. The element carbon is the most common example exhibiting polymorphism. It exists in the form of graphite hexagonal , diamond cubic and as fullerenes C60, C70 , and are shown in Fig.
Conformationally rigid molecules exhibit orientational or packing polymorphism. Conformational polymorphism arises when a flexible molecule adopts different conformations in different crystal structures[5]. Taste depends on which crystalline forms predominate.
Some of these crystalline forms are not very palatable—others are sensational. Cocoa butter, the main solid fat in chocolate, can crystallize into six polymorphs. The form that predominates in the best-tasting chocolate is form V. This polymorph also makes the chocolate look glossy and melts in the mouth. Most organic substances exist in solid state as polymorphs, pseudo-polymorphs solvates or amorphous forms.
Since all the physicochemical properties in solid state are affected mainly in terms of solubility, dissolution, bioavailibility, processability and stability, it is mandatory[6] to investigate the polymorphic behaviour of active ingredients. Pseudo-polymorphism is applicable for hydrates and solvates. Now-a-days research and material properties of active drug compounds and excipients excipients are ingredients included in a pharmaceutical preparation for the purpose of improving its physical qualities is an integral part of drug development.
Polymorphism in Pharmaceutical Compounds 41 2. They exhibit different melting points, solubilities, X-ray crystal and diffraction pattern.
0コメント