ABSTRACT
To estimate the frequencies of self-reported middle ear and hearing complaints and vertigo/dizziness in adult Greenlanders. Furthermore, to examine if there has been a development in the frequency of these complaints within a 20-year period. A structured questionnaire concerning middle ear disease and related neuro-otological symptoms was mailed to 400 randomly selected adult Greenlanders between 18 and 60 years of age in 1995. In 2014, the questions were included for the same age group in the general Greenlandic Health Survey. The questionnaires contained a total of six identical questions. In 1995, 281 participants (70%) replied to the questionnaire. In 2014, 1,639 participants (78%) replied. We found that in 1995 the two youngest age groups (18-29- and 30-39-year-olds) had the highest relative number of ear discharge. Approximately one-third of the participants in these two age groups reported to have had ear discharge, while this was only reported by 17% of the 18-29-year-olds and 16% of the 30-39-year-olds in 2014 (95% CI [0.03, 0.3] and [0.1, 0.3], respectively). The oldest age group indicated the lowest relative number of experiences of ear discharge in both 1995 and 2014 (18% and 17%, respectively). In 1995, 30% in the age group 30-39-year-olds reported hearing loss, whereas only 18% reported hearing loss in 2014 (p < 0.05, 95% CI [-0.003,0.2]). There was no significant difference in reported ear discharge since childhood and otitis media in childhood among the age groups between 1995 and 2014. However, in 1995 significantly more females had experienced ear discharge in the age groups 18-29 and 30-39 year-olds compared to 2014. Females in the age group 18-29 year-olds also showed a significant difference in having experienced otitis media in childhood, where 32% answered "yes" in 1995, and 18% answered "yes" in 2014 (p < 0.05). In 2014, females reported more frequent complaints of vertigo compared to males, 16% and 9%, respectively (p < 0.05). In 1995, there was no significant difference in experienced vertigo between males and females. Ear and hearing health problems and vertigo are reported frequently in the Greenlandic population. Overall, a tendency of less complaints in 2014 compared to 1995 except for vertigo. It is important to follow this trend and increase the prophylactic efforts to reduce common health disabilities like early otitis media in childhood and noise created symptoms even more.
Subject(s)
Hearing Loss , Female , Male , Adult , Humans , Greenland/epidemiology , Self Report , Prevalence , Hearing Loss/epidemiology , Vertigo/epidemiologyABSTRACT
The synthesis of a number pyrrolo-annelated tetrathiafulvalenes, including the parent bis(pyrrolo[3,4-d])tetrathiafulvalene (7) is decribed. Starting from readily available 4,5-bis(bromomethyl)-1, 3-dithiole-2-thione (14) and sodium tosylamide, the parent 7 and the asymmetric monopyrrolo tetrathiafulvalenes 23a,b were prepared in good yields via a nonclassical and simple pyrrole synthesis. Furthermore, a series of asymmetrical N-alkylated monopyrrolo/monodihydropyrrolotetrathiafulvalenes was prepared starting from primary amines and 14. A detailed study of the fundamental redox behavior of this class of heterocycles is reported. NMR spectroscopy, cyclic voltammetry, and PM3 MO calculations revealed that the pyrrolo-annelated tetrathiafulvalenes have highly extended pi-surfaces. The X-ray crystallographic analyses of the monopyrrolo tetrathiafulvalenes 22b and 24b, together with preliminary formation of a charge-transfer complex between the parent donor 7 and TCNQ, are also reported.
ABSTRACT
The tris-tetrathiafulvalene (TTF) macrocycles 3 with a large end-cavity were effectively synthesized from the readily available tetrakis(cyanoethylthio)TTF by means of a selective deprotection/realkylation sequence followed by an intramolecular coupling reaction. Crystar structure analyses revealed that the neutral molecules include two (3a) or one chloroform molecule (3b) as solvent of crystallization inside the cavity, whereas the I3- salt of 3b, obtained by electrocrystallization, has a molecular structure which is different from that of the neutral molecule in that the cavity has completely collapsed.
ABSTRACT
The geometry of the 4,8,12-trioxa-4,8,12,12c-tetrahydrodibenzo[cd,mn]pyrene system in the cationic state was established by X-ray structural resolution of the salts formed between the cation and various anions. The geometry was found to be planar for the 4,8,12-trioxa-4,8,12,12c-tetrahydrodibenzo[cd,mn]pyrenylium and 2,6,10-tri(tert-butyl)-4,8,12-trioxa-4,8,12,12c-tetrahydrodibenzo[cd,mn]pyrenylium cations with the monovalent anions I(-), BF(4)(-), PF(6)(-), AsF(6)(-), HNO(3).NO(3)(-) and CF(3)SO(3)(-), and the divalent anions S(2)O(6)(2-) and Mo(6)Cl(14)(2-). The salts were found to crystallize in distinct space groups following a characteristic pattern. Mixed cation-anion stacking resulted in space groups with high symmetry: Pbca in three cases and R3;c in one; a temperature study of the latter was made at ten different temperatures. The formation of dimers of anions and cations resulted in lower-symmetry space groups, mainly monoclinic (P2(1)/n, P2(1)/c and C2/c), but also P1;.
