Perceived School Experience of Children and Adolescents With Type 1 Diabetes in the Kingdom of Saudi Arabia.

BACKGROUND AND OBJECTIVE: Type 1 diabetes mellitus (T1DM) is one of the most common chronic diseases in children globally affecting more than 1.2 million children worldwide. It is challenging to manage in children and adolescents, as it can have much more serious psychosocial impacts in these groups. The objective of this study was to investigate the perceived experience of children and adolescents with T1DM regarding the management of their condition while in school. METHODS:  We used a cross-sectional study design with descriptive statistics and non-probability consecutive sampling in this work. This study was conducted at the Department of Pediatrics, Qassim Armed Forces Hospital, Al-Qassim, Saudi Arabia, from July 2018 to December 2018. In this study, we included 84 school-aged children and adolescents from various schools in the Qassim region of the Kingdom of Saudi Arabia who had T1DM and met the inclusion criteria. After we obtained written informed consent from the participants, they filled out a survey questionnaire about their perceived school experience while being a T1DM patient. RESULTS:  Although most of the children believed that they were not prevented from managing their diabetes at school, most also believed that school personnel did not have adequate knowledge about diabetes. CONCLUSION:  In this study, adolescents and children with T1DM had mixed perceptions of their experience at school.

The molecular structure and vibrational, (1)H and (13)C NMR spectra of lidocaine hydrochloride monohydrate.

The structure, vibrational and NMR spectra of the local anesthetic drug lidocaine hydrochloride monohydrate salt were investigated by B3LYP/6-311G(∗∗) calculations. The lidocaine·HCl·H2O salt is predicted to have the gauche structure as the predominant form at ambient temperature with NCCN and CNCC torsional angles of 110° and -123° as compared to 10° and -64°, respectively in the base lidocaine. The repulsive interaction between the two N-H bonds destabilized the gauche structure of lidocaine·HCl·H2O salt. The analysis of the observed vibrational spectra is consistent with the presence of the lidocaine salt in only one gauche conformation at room temperature. The (1)H and (13)C NMR spectra of lidocaine·HCl·H2O were interpreted by experimental and DFT calculated chemical shifts of the lidocaine salt. The RMSD between experimental and theoretical (1)H and (13)C chemical shifts for lidocaine·HCl·H2O is 2.32 and 8.21ppm, respectively.

The conformational stability, solvation and the assignments of the experimental infrared, Raman, (1)H and (13)C NMR spectra of the local anesthetic drug lidocaine.

The structure, vibrational and (1)H and (13)C NMR spectra of the local anesthetic drug lidocaine were investigated by the B3LYP/6-311G(∗∗) calculations. The molecule was predicted to have the non-planar cis (NCCN∼0°) structures being about 2-6kcal/mol lower in energy than the corresponding trans (NCCN∼180°) forms. The calculated NCCN (9.6°) and CNCC (-132.2°) torsional angles were in a good qualitative agreement with the reported X-ray angles (3.1 and 13.0°, -102.67 and -77.9°, respectively, for H-bonded dimers). The Gibbs energy of solution of lidocaine in formamide, water, dimethylsulfoxide, acetonitrile, methanol, ethanol and chloroform solutions was estimated at the B3LYP level. The predicted affinity of lidocaine toward the alcohols, acetonitrile and chloroform solutions was in excellent agreement with the reported experimental solubility of the drug in organic solvents. The analysis of the observed vibrational spectra is consistent with the presence of lidocaine in only one conformation at room temperature. The (1)H and (13)C NMR spectra of lidocaine were interpreted by experimental and DFT calculated chemical shifts of the drug. The RMSD between experimental and theoretical (1)H and (13)C chemical shifts for lidocaine is 0.47 and 8.26ppm, respectively.

A comparative study of the conformational equilibria, vibrational, (1)H and (13)C NMR spectra of isobutyranilide and its derivative the anticancer drug flutamide.

The molecular structure of isobutyranilide and flutamide were investigated by DFT-B3LYP/6-311G(**) and MP2/6-311G(**) calculations. Isobutyranilide was predicted to exist predominantly in a planar cis conformation, while flutamide in non-planar structures with the CF3 and the NO2 groups adopting an out of the phenyl-plane configuration. The vibrational frequencies of the low energy structures of the two molecules were computed at the DFT-B3LYP level of theory. From the calculated Gibb's free energies, isobutyranilide is estimated to have an equilibrium mixture of 91% cis and 9% trans structures, while flutamide is calculated to have a mixture of 65% cis-cis and 28% trans-cis structures at 298.15K. The analysis of the observed vibrational spectra supports the presence of isobutyranilide in only one conformation at room temperature. From a 1:1 acetonitrile solvent experiment flutamide is determined to exist in more than one conformation at ambient temperature. Complete vibrational assignments of the normal modes of isobutyranilide and flutamide were provided on the basis of combined normal coordinate calculations and experimental Infrared and Raman spectra. The (1)H and (13)C NMR spectra of isobutyranilide were measured and their chemical shifts were compared to the corresponding ones of flutamide.

Analysis of the molecular structure and vibrational spectra of the indole based analgesic drug indomethacin.

The stability of the syn and anti structures of the non-steroidal anti-inflammatory drug indomethacin were investigated by the DFT-B3LYP and ab initio MP2 calculations with the 6-311G(**) basis set. The molecule was predicted at the DFT and MP2 levels of calculation to have the syn (C1N7C10C18 ∼40°) form being about 1.7 and 1.5kcal/mol, respectively lower in energy than the anti (C1N7C10C18 ∼140°) structure. The calculated CNCC torsional angles for the chlorobenzene and indole rings syn-anti conformational interconversion was in a good qualitative agreement with the reported X-ray angles (C1N7C10C18 ∼29 and 155°) for the syn and anti conformers, respectively). Indomethacin was estimated from the calculated Gibb's free energies to have an equilibrium mixture of 95% syn and 5% anti structures at 298.15K. The vibrational wavenumbers were computed at the B3LYP level of theory and complete vibrational assignments were provided on the basis of theoretical and normal coordinate calculations combined with experimental infrared and Raman data of the molecule. The analysis of the observed spectra supports the presence of indomethacin in only one conformation at room temperature.

A comparative study of the infrared and Raman spectra of aniline and o-, m-, p-phenylenediamine isomers.

The structural stabilities of o-, m- and p-phenylenediamine (PDA) isomers were investigated by DFT-B3LYP and ab initio MP2 calculations with the 6-311G(**) basis set. From the calculations the three isomers were predicted to exist predominantly in an anti (transoid) structure. In the o-isomer, the syn (cisoid) form is calculated to turn to the anti (transoid) form with the two HNCC torsional angles of about 44 and 10° and the NH2 inversion barrier of 3-4 kcal/mol. The CCNH torsional angles in the m-PDA and p-PDA isomers were calculated to be about 25-26° as compared to 20° in aniline. A comparison of the Raman spectra of the three PDA-s with those of aniline shows the high sensitivity of the ring breathing mode to the nature of substituents in the aniline ring. The vibrational wavenumbers were computed at the DFT-B3LYP for aniline and the o-, m- and p-PDA isomers for the purpose of comparison. Complete vibrational assignments were made on the basis of normal coordinate analyses and potential energy distributions for aniline and the o-, m- and p-PDA molecules.

A comparative study of the structure and vibrational spectra of diphenylmethane, the carcinogen 4,4'-methylenedianiline and 4,4'-methylenebis(N,N-dimethylaniline).

The structural stability of 4,4'-methylenedianiline (MDA), 4,4'-methylenebis(N,N-dimethylaniline) (MBDMA) and their parent diphenylmethane (DPM) was investigated by the DFT-B3LYP and ab initio MP2 calculations with the 6-311G(**) basis set. From the calculations the three diphenylmethanes were predicted to exist predominantly in a non-planar structure with a near C2 molecular symmetry in agreement with X-ray studies. The CCCC angles in DPM and the two dianilines were calculated to be nearly equal of about 60° as compared to X-ray angles of 17° and 67° for MDA. The NH2 inversion barriers in MDA was estimated to be about 1-5 kcal/mol. On comparison of the Raman spectra of the three compounds, the line intensity and position of the characteristic ring breathing mode were shown to be sensitive to the amino substitution. The vibrational wavenumbers of the optimized structures of the two dianilines were computed at the DFT-B3LYP level of theory. Tentative vibrational assignments were made on the basis of combined DFT and experimental FT-IR and FT-Raman data of MDA and MBDMA.

Analysis of the infrared and Raman spectra of the symmetrically substituted 1,3-diphenylurea and 1,3-diphenylacetone (dibenzyl ketone).

The structural stability of 1,3-diphenylurea and 1,3-diphenylacetone was investigated by the DFT-B3LYP and ab initio MP2 calculations using the 6-311G(**) basis set. From full energy optimization at the MP2 level of theory the near-planar cis-trans form of 1,3-diphenylurea was predicted to be about 1.5kcal/mol lower in energy than the X-ray near-planar cis-cis conformer. At the DFT-B3LYP level of theory the near-planar cis-trans and cis-cis forms were predicted to have a very comparable relative stability. The dibenzyl ketone was predicted by both levels to exist predominantly in a gauche-gauche conformation. On comparison the DFT near-planar structures of each of the two molecules were found to be consistent with the reported X-ray structures. The analysis of the infrared and Raman spectra of 1,3-diphenylurea suggests the presence of a second form at room temperature. The vibrational frequencies of the conformers most consistent with X-ray data of diphenylurea and dibenzyl ketone were computed at the B3LYP level and tentative vibrational assignments of their normal modes were provided on the basis of combined experimental and computed data.

A study of the molecular structure and vibrational spectra of 1,3-dichloro-2-propanol and 1,1,1-trichloro-2-methyl-2-propanol (chlorobutanol).

The conformational stability of 1,3-dichloro-2-propanol and 1,1,1-trichloro-2-methyl-2-propanol (chlorobutanol) was investigated by the DFT-B3LYP/6-311+G**, MP2/6-311+G** and MP4(SDQ)/6-311+G** levels of theory. From the calculations chlorobutanol was predicted to exist in a non-planar gauche structure. The planar cis and trans structures of chlorobutanol were calculated to be about 3kcal/mol higher in energy than the gauche structure. From the calculations 1,3-dichloro-2-propanol was predicted to exist in a Ggg1 and Ggg conformational mixture at ambient temperature. In the low energy structures of both alcohols the non-bonded Cl⋯H(O) distance was calculated to be of about 2.6-2.7Å. The observation of a broad and very intense band at about 3400cm(-1) in the infrared spectra of the two alcohols supports the presence of strong intermolecular Cl⋯H(O) dipolar interactions in their condensed phases. The analysis of the Raman spectra of 1,3-dichloro-2-propanol suggests the presence of a second high energy Ggg structure of the dichloride at room temperature. The vibrational frequencies of 1,3-dichloro-2-propanol and chlorobutanol in their low energy structures were computed at the B3LYP level and tentative vibrational assignments were made for their normal modes on the basis of combined calculated and experimental data.

Vibrational spectra and assignments of 2-phenylethanol and 2-phenoxyethanol.

The structural stability of 2-phenyl- and 2-phenoxyethanols were investigated at the DFT-B3LYP/6-311G**, MP2 and MP4(SDQ) levels of theory. From the calculations at the three levels of theory 2-phenylethanol and 2-phenoxyethanol were predicted to exist predominantly in non-planar gauche conformations. For 2-phenylethanol the lowest energy Gg1 structure was predicted to be stabilized by an interaction between the hydroxyl H atom and the phenyl ring. For 2-phenoxyethanol the Ggg1 structure was predicted to be strongly stabilized by dipolar interactions between the hydroxyl H atom and the phenoxy O atom of the alcohol. For both alcohols the planar trans structure with minimum steric interactions between the CH(2) groups was predicted to be significantly higher in energy than the ground state gauche structure of the alcohols. The dipolar interactions are reported to play more important role than steric ones in stabilizing the molecules. The vibrational frequencies of each of the two alcohols in its lowest energy gauche structure were computed at the B3LYP level and tentative vibrational assignments were made for their normal modes on the basis of the calculated and experimental data.

Analysis of the infrared and Raman spectra of phenylacetic acid and mandelic (2-hydroxy-2-phenylacetic) acid.

The structural stability of phenylacetic acid and mandelic acid was investigated by the DFT-B3LYP and the ab initio MP2 calculations with the 6-311G** basis set. The two molecules were predicted at the DFT and MP2 levels of calculation to have the non-planar (Np) forms as their lowest energy structures. The observed spectral intensities of the acids were consistent with the Np conformation being the predominant form at room temperature. The vibrational wavenumbers were computed at the B3LYP level of theory and tentative vibrational assignments were provided on the basis of combined theoretical and experimental infrared and Raman data of the molecules. The sharpness of the methylenic O-H stretching mode in the IR spectrum of mandelic acid suggests the absence of intermolecular dimerization in the acid which is supported by the observation of no splitting of its CO stretching mode.

Molecular structure and vibrational assignments of 2,4-dichlorophenoxyacetic acid herbicide.

The structural stability of 2,4-dichlorophenoxyacetic acid was investigated by the DFT-B3LYP and the ab initio MP2 calculations with the 6-311G** basis set. From the calculations at both levels of theory the Cgcpp structure was predicted to be the lowest energy minimum for the acid. The DFT and the MP2 levels disagreed about the nature of the second stable structure of 2,4-dichlorophenoxyacetic acid. At the DFT-B3LYP level of calculation the planar Tttp (transoid O=C-O-H) and the non-planar Tgcpp (cisoid O=C-O-H) forms were predicted to be 0.7 and 1.5 kcal/mol, respectively higher in energy than the Cgcpp conformation. At the MP2 level the two high energy Tttp and Tgcpp forms were predicted to be 2.7 and 1.4 kcal/mol, respectively higher in energy than the ground state Cgcpp structure. The Tgcpp form was adopted as the second possible structure of 2,4-dichlorophenoxyacetic acid on the basis of the fact that the Møller-Plesset calculations account better than the DFT ones for the non-bonding Ocdots, three dots, centeredH interactions. The vibrational frequencies of the lowest energy Cgcpp conformer were computed at the B3LYP level of theory and tentative vibrational assignments were provided on the basis of normal coordinate analysis and experimental infrared and Raman data.

A study of the conformational stability and the vibrational spectra of 2,3-dichloro-1-propanol.

The conformational stability and the three rotor internal rotations in 2,3-dichloro-1-propanol were investigated at DFT-B3LYP/6-311+G**, MP2/6-311+G** and MP4(SDQ) levels of theory. From the calculated potential energy surface, ten distinct minima were located all of which were predicted to have real frequencies at the B3LYP level of theory. The calculated lowest energy minima in the potential curves of the molecule were predicted to correspond to the Ggg and Gtg1 structures. The observed broad and very intense infrared band centered at about 3370 cm(-1) supports the existence of the strong intermolecular H-bonding in 2,3-dichloro-1-propanol. The equilibrium constants for the conformational interconversion in the molecule were estimated from the calculated Gibb's energies at the B3LYP/6-311+G** level of calculation and found to correspond to an equilibrium mixture of about 49% Ggg, 27% Gtg1, 5% Ggt and 5% Tgg conformations at 298.15K.

A study of internal rotations and vibrational spectra of oxiranemethanol (glycidol).

The conformational stability and the C-O and O-H internal rotations in oxiranemethanol were investigated at the DFT-B3LYP/6-311 G**, MP2/6-311 G** and MP4(SDQ)/6-311 G** levels of theory. Three minima were predicted in the CCOH potential energy scans of the molecule to have relative energies of about 2 kcal/mol or less and all were calculated to have real frequencies upon full optimization of structural parameters at the DFT and the MP2 levels of calculations. The Cg1 (H bond inner) conformation was predicted to be the lowest energy conformation for oxiranemethanol in excellent agreement with an earlier microwave study. The equilibrium mixture was calculated from Gibb's free-energy changes to be about 79% Cg1, 17% G1g and 3% Gg1 at the B3LYP/6-311G** level and about 87% Cg1, 11% G1g and 2% Gg1 at the MP2/6-311 G** level for oxiranemethanol at 298.15 K. No conclusive evidence was obtained for the presence of high-energy form in the liquid phase of oxiranemethanol. The vibrational frequencies of oxiranemethanol in its three stable forms were computed at the B3LYP level and complete vibrational assignments were made for the lowest energy Cg1 form on basis of calculated and experimental data of the molecule.

A study of conformational stability and vibrational assignments of 1-aminocyclopropanecarboxylic acid c-C3H4(NH2)-COOH.

The structural stability of 1-aminocyclopropanecarboxylic acid was investigated at DFT-BLYP, DFT-B3LYP and ab initio MP2 levels of theory with 6-311G(**) basis set. The molecule was predicted at the three levels of calculation to exist in cis-syn<-->trans-syn conformational equilibrium. The equilibrium constants for the conformational interconversion were calculated and found to correspond to an equilibrium mixture of about 35% cis-syn and 65% trans-syn conformations at 298.15 K. The cis-trans rotational barrier and the NH(2)syn-anti inversion barrier were estimated to be about 6 and 7 kcal/mol, respectively. The O-H rotational barrier was calculated to be of the order 12-14 kcal/mol. The vibrational frequencies of the two stable conformers of the acid were computed at the BLYP and the B3LYP levels of theory. Only vibrational assignments were provided for the low energy trans-syn conformer on the basis of normal coordinate analysis and experimental data. No clear evidence was found for the presence of the second high energy cis-syn structure in the spectra of the molecule.

Structural stability, C--N internal rotations and vibrational spectral analysis of non-planar phenylurea and phenylthiourea.

The structural stability and C-N internal rotations of phenylurea and phenylthiourea were investigated by DFT-B3LYP and ab initio MP2 and MP4//MP2 calculations with 6-311G** and/or 6-311+G** basis sets. The complex multirotor internal rotations in phenylurea and phenylthiourea were investigated at the B3LYP/6-311+G** level of theory from which several clear minima were predicted in the calculated potential energy scans of both molecules. For phenylurea two minima that correspond to non-planar- (CNCC dihedral angle of about 45 degrees ) cis (CNCO dihedral angle is near 0 degrees ) and trans (CNCO dihedral angle is near 180 degrees ) structures were predicted to have real frequency. For phenylthiourea only the non-planar-trans structure was predicted to be the low energy minimum for the molecule. The vibrational frequencies of the lowest energy non-planar-trans conformer of each of the two molecules were computed at the B3LYP level and tentative vibrational assignments were provided on the basis of normal coordinate analysis and experimental infrared and Raman data.

Analysis of vibrational spectra of 3-halo-1-propanols CH(2)XCH(2)CH(2)OH (X is Cl and Br).

The conformational stability and the three rotor internal rotations in 3-chloro- and 3-bromo-1-propanols were investigated by DFT-B3LYP/6-311+G and ab initio MP2/6-311+G, MP3/6-311+G and MP4(SDTQ)//MP3/6-311+G levels of theory. On the calculated potential energy surface twelve distinct minima were located all of which were not predicted to have imaginary frequencies at the B3LYP level of theory. The calculated lowest energy minimum in the potential curves of both molecules was predicted to correspond to the Gauche-gauche-trans (Ggt) conformer in excellent agreement with earlier microwave and electron diffraction results. The equilibrium constants for the conformational interconversion of the two 3-halo-1-propanols were calculated at the B3LYP/6-311+G level of calculation and found to correspond to an equilibrium mixture of about 32% Ggt, 18% Ggg1, 13% Tgt, 8% Tgg and 8% Gtt conformations for 3-chloro-1-propanol and 34% Ggt, 15% Tgt, 13% Ggg1, 9% Tgg and 7% Gtt conformations for 3-bromo-1-propanol at 298.15K. The nature of the high energy conformations was verified by carrying out solvent experiments using formamide ( epsilon=109.5) and MP3 and MP4//MP3 calculations. The vibrational frequencies of each molecule in its three most stable forms were computed at the B3LYP level and complete vibrational assignments were made based on normal coordinate calculations and comparison with experimental data of the molecules.

Solvent dependence of conformational stability and analysis of vibrational spectra of 2,2,3,3,3-pentafluoro-1-propanol.

The conformational stability of 2,2,3,3,3-pentafluoro-1-propanol was investigated by the DFT-B3LYP/6-311+G** and the ab initio MP2/6-311+G** calculations. The calculated potential energy curves of 2,2,3,3,3-pentafluoro-1-propanol at both levels of theory were consistent with three distinct minima that correspond to Trans-gauche-gauche (Tgg), trans-trans-gauche (Ttg) and trans-gauche-gauche(-) (Tgg1) conformers in the order of decreasing relative stability. The equilibrium constants for the conformational interconversion of 2,2,3,3,3-pentafluoro-1-propanol were calculated and found to correspond to an equilibrium mixture of about 46% Tgg, 43% Ttg and 11% Tgg1 conformations at 298.15K. The calculated (%Ttg/%Tgg) ratio of 0.93 is consistent with the 0.85 ratio of the observed intensities of the 772 and 794 cm(-1) lines in the Raman spectrum of the liquid. The nature of the high energy Ttg conformation was verified by solvent experiments using formamide (epsilon = 109.5) and acetonitrile (epsilon = 37). The vibrational frequencies of the molecule in its stable forms were computed at B3LYP level and complete vibrational assignments were made based on normal coordinate calculations and comparison with experimental data of the molecule.

Ring inversion, structural stability and vibrational assignments of sulfolane c-C4H8SO2 and 3-sulfolene c-C4H6SO2.

The structural stability of sulfolane (tetrahydrothiophene1,1-dioxide) and 3-sulfolene (dihydrothiophene1,1-dioxide) was investigated by DFT-B3LYP and ab initio MP2 calculations with 6-311+G**) basis set. The calculated symmetric ring-puckering potential of 3-sulfolene at the B3LYP level is consistent with a flat minimum that corresponds to a planar ring but at the MP2 level with a double minimum with a low barrier of about 193 cal mol(-1) to ring planarity in reasonable agreement with experimental results. From the calculations at the two levels of theory sulfolane was predicted to exist predominantly in the twist conformation. The vibrational wavenumbers were calculated at the MP2/6-31G** level of theory and the potential energy distributions PED among the symmetry coordinates of the normal modes were computed for the low-energy structure of the molecules. Complete vibrational assignments were provided on the basis of the calculated PED values. The experimental infrared and Raman spectra of the two molecules were compared to the calculated ones.

Three rotor potential energy scans, conformational equilibrium constants and vibrational analysis of 3-fluoro-1-propanol CH(2)FCH(2)CH(2)OH.

The conformational stability and the three rotor internal rotations in 3-fluoro-1-propanol were investigated by the DFT-B3LYP/6-311+G** and the ab initio MP2/6-311+G** levels of theory. The calculated potential energy curves of the molecule at both levels of theory were consistent with complex conformational equilibria of about 12 minima, all of which were predicted to have real frequencies at both the B3LYP and the MP2 levels. The lowest energy minimum in the potential curves of 3-fluoro-1-propanol was predicted to correspond to the Gauche-gauche-trans (Ggt) conformer in excellent agreement with microwave and electron diffraction results. The equilibrium constants for the conformational interconversion of the molecule were calculated and found to correspond to an equilibrium mixture of about 33% Ggt, 14% Ggg1 and 13% Gg1g and about 43% Ggt, 12% Ggg1 and 10% Gg1g distribution by the B3LYP/6-311+G** and the MP2/6-311+G** calculations, respectively, at 298.15K. The vibrational frequencies of each molecule in its three stable forms were computed at B3LYP level and complete vibrational assignments were made based on normal coordinate calculations and comparison with experimental data of the molecule.