ABSTRACT
BACKGROUND: Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiac disorder and shows high variability in genetic heterogeneity and phenotypic characteristics. The genetic etiology responsible for HCM in many individuals remains unclear. OBJECTIVE: This instigation was sought to identify novel genetic determinants for familial hypertrophic cardiomyopathy. METHODS: Six unrelated Chinese families with HCM were studied. For each of the 13 established HCM-susceptibility genes, 3 to 5 microsatellite markers were selected to perform genotyping and haplotype analysis. The linked genes were sequenced. RESULTS: Haplotype analyses on candidate genetic loci revealed cosegregation of the gene beta-myosin heavy chain (MYH7) with HCM in a single family. A novel double heterozygous missense mutation of Ala26Val plus Arg719Trp in MYH7 was subsequently identified by sequencing in this family and was associated with a severe phenotype of HCM. CONCLUSION: The novel double mutation of Ala26Val plus Arg719Trp in MYH7 identified in a Chinese family highlights the remarkable genetic heterogeneity of HCM, which provides important information for genetic counseling, accurate diagnosis, prognostic evaluation, and appropriate clinical management.
Subject(s)
Cardiac Myosins/genetics , Cardiomyopathy, Hypertrophic, Familial/genetics , Mutation, Missense , Myosin Heavy Chains/genetics , Adolescent , Adult , Aged , Base Sequence , Cardiomyopathy, Hypertrophic, Familial/diagnosis , Child , China , DNA Mutational Analysis , Echocardiography, Doppler , Electrocardiography , Female , Genetic Predisposition to Disease , Haplotypes , Heterozygote , Humans , Male , Microsatellite Repeats , Molecular Sequence Data , Pedigree , Phenotype , Risk Factors , Severity of Illness IndexABSTRACT
A two-dimensional infrared (2D IR) correlation spectroscopy technique has been introduced to study the intermolecular interaction between 4-aminopyridine and methacrylic acid. The type and relationship of the bond between 4-aminopyridine and methacrylic acid molecule could not be characterized directly using the one-dimensional FTIR spectroscopy. On the contrary, the interactions between 4-aminopyridine and methacrylic acid molecule were determined using 2D IR correlation spectroscopy. The synchronous cross peaks exist between stretching vibrations of hydroxyl group of methacrylic acid at 1298 and 1202 cm(-1) and C=N group of 4-aminopyridine at 1531 cm(-1), and between carbonyl group of methacrylic acid at 1705 cm(-1) and N-H group of 4-aminopyridine at 3382 and 3212 cm(-1), respectively. According to the two-dimensional correlation rules, the interactions of static electricity and hydrogen bonding exist between 4-aminopyridine and methacrylic acid molecule. Such successful applications demonstrate that two-dimensional infrared correlation spectroscopy may be a convenient and effective means in the study of the intermolecular and intramolecular interaction.
ABSTRACT
In-situ FTIR spectroscopy is a rising and dynamic technique. This technique combines the advantages of investigation in-situ and accurate structure analysis by FTIR spectroscopy, and can detect real time chemical change in materials at different temperatures and obtain the relationship between micromechanism of materials and temperature. In the present paper, thermal decomposition of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) heated with a rate of 5, 10, 20 and 40 degrees C x min(-1), respectively, was investigated by in-situ diffuse reflection FTIR spectroscopy. The results demonstrate that intramolecular cyclization occurs in breakage of HMX with a heating rate of 5 degrees C x min(-1), while intermolecular cyclization appears with a heating rate of 10, 20 and 40 degrees C x min(-1). With increasing temperature, the rupture rate of C-N bond is faster than that of N-N bond, which verifies that the cleavage of C-N bond is the dominant rupture form. With increasing heating rate, the decomposition beginning temperature of C-N bond increases. Eight kinds of gaseous products such as CO2, N2O, CO, NO, HCHO, HONO, NO2 and HCN were determined. The decomposition mechanism of HMX was not affected with changing heating rate.
ABSTRACT
In-situ FTIR spectroscopy is a rising and dynamic technique. This technique, which combines the advantages of investigation in-situ and accurate structure analysis by FTIR spectsoscopy, can detect the chemical change of materials in different temperature with real time and obtain the relationship between micromechanism of materials and temperature. In the present paper, thermal decomposition of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) heated with 5 degrees C x min(-1) was investigated by in-situ FTIR spectroscopy. The results demonstrate that C-N bond cleavage and N-N bond cleavage of HMX occur at 205 degrees C. With increasing temperature, the rupture rate of C-N bond is faster than that of N-N bond, which verifies that the cleavage of C-N bond is the dominant rupture form. The augment in tension of HMX cyclic confirms that intramolecular cyclization occurs in breakage of HMX. Eight kinds of gaseous products such as CO2, N2O, CO, NO, HCHO, HONO, NO2 and HCN were determined. According to the structure change in condensed state and gaseous products, the decomposition mechanism was deduced that HCHO, N2O, HONO and HCN were released due to the cleavage of C-N bond, and NO2 was released due to the cleavage of N-N bond.
