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Prague, Czech Republic

Klusackova P.,Klinika Pracovniho Lekarstvi 1. LF UK A VFN | Lebedova J.,Klinika Pracovniho Lekarstvi 1. LF UK A VFN | Fenclova Z.,Klinika Pracovniho Lekarstvi 1. LF UK A VFN | Vlckova S.,Klinika Pracovniho Lekarstvi 1. LF UK A VFN | And 5 more authors.
Alergie | Year: 2013

Diagnostics of occupational asthma is based on positive results of bronchoprovocation tests (BPT) with occupational allergens. It is necessary to look for new methods which could make the diagnostics more precise. Twenty persons were tested with suspicion on occupational asthma. Except standard tests also leukotrienes (LT) B4, C4, D4, E 4, 8-isoprostane, malondialdehyde and 4-hydroxy-trans-2-nonenal in breath condensate, plasma and urine were analyzed. Examination was performed before BPT, after the non-specific bronchoprovocation test (nBPT) with methacholine and after specific bronchoprovocation tests with occupational allergens (sBPT). Specific bronchoprovocation tests were positive in 10 persons. In the group of patients with positive results of sBPT more frequently nBPT was positive (p = 0.002). Significant difference was found between groups with negative and positive results of sBPT in pH of breath condensate (p = 0.012). Within the group with positive sBPT significant decrease of 8-isoprostane was found in plasma after nBPT and sBPT (p = 0.006 a 0.049) compared to the basal value and significant increase of LTE4 in plasma after sBPT compared to the value after nBPT (p = 0.037). Source

On the occasion of 60 years anniversary of founding Institute of Chemical Technology as independent academic institution the parallel history of its Central Library is summarized. It is stressed that despite of unfavourable economical and political condition in Czech Republic for most of this time range the Central Library was able to maintain relative high standard not only as classical library but also to keep pace with development of electronic forms of scientific information. Thanks to this after opening of physical and financial borders Central Library was able systematically build up collection of digital information resources, both the secondary chemistry databases like CA, Beilstein or Gmelin but also very large collection of primary journals including so called archive collection covering full runs of most chemistry titles. Source

The posibility of comparing textual description of a problem is a clear advantage of the SciFinder resulting from abundant indexing of the paper content done by specialists in contrast to the description based on the paper title and abstract only. Search for individual compounds affords comparable results for both databases because both use the same principles of excerpting all compounds studied in a given document. In reaction search the advantage of Reaxys is distinct, much like the former databases Beilstein and Gmelin, which are built as reaction databases. The reaction module CASREACT in SciFinder is comparable with the Reaxys in the last 30-40 years only but offers no data for inorganic reactions. The patent search in Chemical Abstracts (CA) with traditional indepth coverage of patents and in the Reaxys are strong in looking for data of both organic and inorganic compounds. Despite the attempts of both databases at extending coverage and being competitive, the concept based on bibliographic records in CA and compound listing in Beilstein or Gmelin lead to different results, which is advantageous for completeness and relevance of the results. Source

Vaclavika J.,Ustav Organicke Technology | Pechacek J.,Ustav Organicke Technology | Precha J.,Ustav Organicke Technology | Kuzmab M.,Laborator charakterizace molekularni struktury | And 2 more authors.
Chemicke Listy | Year: 2012

Three methods for determination of enantioselectivity of asymmetric transfer hydrogenation of imines are presented: direct NMR observation of diastereomeric reduction products of a chiral imine, chiral solvation with Pirkle's alcohol, (-)-(1R)-1-(9-anthryl)-2,2,2-trifluoroethan-1-ol and precolumn derivatization with (-)-(1R)-menthyl chloroformate followed by GC analysis on a non-chiral column of the resulting diastereomeric carbamates. Source

Krejzova E.,Ustav Organicke Technology | Belohlav Z.,Ustav Organicke Technology
Chemicke Listy | Year: 2014

Orally dispersible tablets (ODT) are important for their fast disintegration in mouth as well as for their fast action and high biological availability of the drug. This dosage form is suitable in cases when the tablet swallowing is difficult, either for children or patients with dysphagia or for those who have no access to water. Development of ODT is complicated mainly by masking the unpleasant taste of the drug. It is necessary to keep the critical parameters of the tablets such as their hardness and fast disintegration. There are many methods of taste masking, but their application is very individual. In some cases the taste correction by with sweeteners and flavors can be sufficient, sometimes it is necessary to choose more sophisticated methods such as tablet coating or chemical modification of the active substance. In recent years, the taste masking using cyclodextrins and ion exchangers has been widely used. However, their use is limited to active substances capable of forming stable complexes with the tastemasking agents. The agents can negatively affect the dissolution profile of the active substance as well as slow down tablet disintegration. In a number of ODT efficient taste masking is achieved by a combination of appropriate physicochemical methods and technologies. Source

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