RESUMO
Thiocyameluric acid C6 N7 S3 H3 , the tri-thio analogue of cyameluric acid, is a key compound for the synthesis of new s-heptazine (tri-s-triazine) derivatives. Here, two different routes for the synthesis of thiocyameluric acid and its reaction to tris(aryldithio)- and tris(alkyldithio)cyamelurates C6 N7 (SSR)3 are reported as well as transformation to alkali metal thiocyamelurates M3 [C6 N7 S3 ], M=Na, K. These compounds were characterised by FTIR, Raman, solution 13 C and 1 Hâ NMR spectroscopies, thermal gravimetric analysis (TGA) and elemental analysis. The three (de)protonation steps of thiocyameluric acid were investigated by acid-base titration followed via UV/Vis absorption spectroscopy. While it was not possible to determine the three pKa values, it could be postulated that the acid strength probably increases in the following order: cyanuric acid (C3 N3 O3 H3 ) < thiocyanuric acid (C3 N3 S3 H3 ) < cyameluric acid (C6 N7 O3 H3 ) < thiocyameluric acid (C6 N7 S3 H3 ). Single crystals of Na3 [C6 N7 S3 ]â 10 H2 O and K3 [C6 N7 S3 ]â 6 H2 O were obtained and the structures analyzed by single crystal X-ray diffraction. Additionally, quantum chemical calculations were performed to get insights into the electronic structure of thiocyameluric acid and to clarify the thiol-thione tautomerism. Based on a comparison of calculated and measured vibrational spectra it can be concluded that thiocyameluric acid and the di- and mono-protonated anions exist in the thione form.
RESUMO
Asymmetrically substituted s-triazine phosphonates with up to three different phosphonate groups C3 N3 RR'R" with R, R', R"=PO(OR"') and R"'=for example, methyl, ethyl, isopropyl or n-butyl are interesting as polymer additives like flame retardants. Typically, these compounds are obtained by multiple synthesis steps. However, this leads to high production costs, which are a disadvantage for commercial use. Here we report the one-step synthesis of mixtures of asymmetrical s-triazine phosphonates which is an easy way to adjust the thermal behaviour and other properties such as viscosities of the compounds. The synthesis is based on a Michaelis-Arbuzov reaction. A complete conversion of the reactants to the target compounds is observed which was proofed by detailed 1 H, 13 C and 31 Pâ NMR investigations and elemental analysis. The thermal behaviour was compared with thermogravimetric analysis (TGA).
RESUMO
OBJECTIVE: To compare the effect of two types of counselling brochure on knowledge, attitudes and intention towards combined oral contraceptives (COCs). STUDY DESIGN: Double-blind, parallel-group randomised trial conducted in Germany. Nulliparous women aged 18-24 years were randomly assigned to receive one of two comprehensive information brochures about COCs, their benefits and risks, and alternative contraceptive methods. The first brochure was based on standard recommendations for evidence-based patient information (EBPI). This was restructured and adapted according to the mental models approach (MMA) for the second brochure. The primary endpoint was the change in number of correct answers in a knowledge questionnaire administered directly after the intervention and three months later. The impact on attitudes and intention were secondary outcomes. RESULTS: Before the intervention, women answered 18.9 (standard deviation [SD] 4.2) of 39 knowledge items correctly. After the intervention, the EBPI group (n = 66; p = not significant) improved by 7.6 (SD 5.4) correct answers compared to 8.3 (SD 5.8) in the MMA group (n = 66). After three months, the MMA group (n = 60) maintained an improvement (5.0 [SD 4.8] correct answers vs. pre-intervention measurement). In the EPBI group (n = 64), this value was 3.9 (SD 5.6). The change in correct answers was positively correlated with a change in attitude (r = 0.284, p = 0.001) and intention (r = 0.212, p = 0.015). CONCLUSIONS: The use of detailed evidence-based information brochures - irrespective of the underlying risk communication approach - can be recommended.
Assuntos
Anticoncepcionais Orais Combinados , Conhecimentos, Atitudes e Prática em Saúde , Folhetos , Adolescente , Adulto , Método Duplo-Cego , Prática Clínica Baseada em Evidências , Feminino , Alemanha , Humanos , Inquéritos e QuestionáriosRESUMO
OBJECTIVES: This pilot study aimed at identifying counselling topics relevant to young women, at comparing their perceived and actual knowledge about combined oral contraceptives (COCs), and at determining the appropriate scope of counselling material about benefits and risks of COCs. METHOD: Thirty women aged 18-24 completed an online questionnaire assessing information needs and knowledge about 25 medical conditions under consideration as potential counselling items (benefits, risks and myths) and preferences about counselling material. RESULTS: Respondents were unable to identify non-contraceptive benefits of COCs or potential severe health risks and had some misconceptions. They rated their knowledge of specific COC effects significantly lower than their corresponding interest in the effect. In contrast, the assessment of how well participants felt they were informed about benefits and risks was rated predominantly as 'rather well'. Eleven items were identified as relevant to patients, the most relevant being cancer-related effects of COCs whereas there was less interest in thrombotic risk. Participants preferred detailed counselling materials and considered gynaecologists, patient information leaflets and the internet as their major sources of information. CONCLUSION: While most women were confident of being knowledgeable about COCs, many were unaware of their knowledge gap. Healthcare professionals should proactively educate about items relevant to their patients. Counselling materials provided by the gynaecologist seem to be an appropriate communication channel. Additional efforts are needed to improve knowledge of the thrombotic and other risk associated with COCs.
Assuntos
Anticoncepcionais Orais Combinados , Conhecimentos, Atitudes e Prática em Saúde , Adolescente , Anticoncepcionais Orais Combinados/efeitos adversos , Anticoncepcionais Orais Combinados/farmacologia , Aconselhamento , Feminino , Alemanha , Humanos , Disseminação de Informação/métodos , Internet , Educação de Pacientes como Assunto/métodos , Relações Médico-Paciente , Fatores de Risco , Inquéritos e Questionários , Adulto JovemRESUMO
BACKGROUND: More than 170 weak or partial RHD alleles are currently known. A similar heterogeneity of RHCE alleles may be anticipated, but a large-scale systematic analysis of the molecular bases of altered C, c, E, and e antigenicity in European blood donors was lacking. STUDY DESIGN AND METHODS: Between November 2004 and October 2006, samples collected from 567,105 blood donors in the northwest of Germany were surveyed for weakened and/or discrepant serologic reaction patterns of the C, c, E, or e antigens in automated testing. Samples from 187 donors with systematic typing problems were further investigated by manual typing and in 122 donors by DNA typing. The polymorphisms determining C, c, E, and e, as well as three repeatedly found substitutions, M167K, G96S, and L115R, were tested by PCR-SSP. Further analysis consisted of sequencing of the exons of RHCE. In addition, 13 referred samples were analyzed. RESULTS: RHcE(M167K) known as E variant I was the most frequent allele, found in 70 of 122 analyzed donors. Among 13 referred samples, C typing problems predominated. Overall, 34 different underlying alleles were detected, 23 of which were new. Molecular causes included single-amino-acid substitutions, gene conversions, multiple dispersed amino acid substitutions, protein extensions, and in-frame amino acid deletions. CONCLUSION: In addition to RHcE(M167K), a large number of different alleles are underlying CcEe typing problems. Molecular mechanisms parallel those found in RHD. Elucidation of the molecular bases of variant antigens is important to improve serologic and molecular typing methods.
Assuntos
Alelos , Doadores de Sangue/estatística & dados numéricos , Tipagem e Reações Cruzadas Sanguíneas/métodos , Sistema do Grupo Sanguíneo Rh-Hr/genética , Alemanha , Humanos , Mutação , Reação em Cadeia da PolimeraseRESUMO
Communication regarding the benefits and risks of combined oral contraceptives (COCs) remains a challenge in view of persistent misconceptions about the 'pill'. The aim of this study was to investigate how women understand the benefits and risks of COCs, comparing their assessments with an expert model created from literature- and guideline-based research and reviewed by a sample of gynaecologists using the mental models approach. Two qualitative studies were conducted in Germany - a questionnaire-based study involving 30 gynaecologists with a mean of 218 COC prescriptions on average per month, and in-depth interviews (plus the use of a questionnaire) with 21 women aged 18-24 years. As expected, women reported only a few concepts of benefits and risks unprompted, but further prompting revealed beliefs of many other associations. The women stated an overall positive valence even if the number of negative concepts predominated indicating a latent cognitive dissonance. The major differences compared with the expert model included: (a) a negative association with weight gain, subfertility and teratogenicity, (b) only a partial association of COC intake with thromboembolic conditions, (c) a confusing, rather negative perception of a COC-related effect on cancer and (d) a partial lack of basic knowledge of the active ingredients, time to excretion and mode of action of COCs. Appropriate COC counselling should cover these discrepancies.