2,059 research outputs found
Variations in pulp/tooth area ratio as an indicator of age: a preliminary study
This paper details for age determination of adult from single rooted theeth. The sample consisted of 100 Italians white Caucasioan patients (46 men, 54 womwn) aged between 18 and 72 years. The single rooted maxillary right canine was utilized in this preliminary study. Pulp/root ration, tooth length ratio, pulp/root area and pulp/root width ratios at three different levels were computed. Pearson's correlation coefficients between age and these variables showed that the ratio between pulp and tooth area correlated best with age (r2 = 0,85). Stepwise multiple regression models yielded a linear relationship between pulp/root width at mid-root level and chronological age and a linear relationship when pulp/tooth area was compared to age. Statistical analysis indicated that these two variables explain 84,9% of variations in estimated chronological age. The median of the absolute value of residual errors between actual and estimated ages was less than four years
Age estimation in children by measurement of open apices in teeth
This paper concerns a method for estimating the
age of children based on their teeth. The sample consisted
of 455 Italian white children (213 boys, 242 girls) aged
between 5 and 15 years. The purpose of the present investigation
was to present a method for assessing chronological
age based on the relationship between age and
measurement of the open apices in teeth. Pearson\u2019s correlation
coefficients between age and these variables
showed that the correlations between age and the open
apices in teeth were significant and negative. Furthermore,
gender and the number of teeth with the apical end of the
root canals completely closed (N0) showed a significant
correlation with chronological age. With the aid of a
stepwise multiple regression model, a linear relationship
between open apices, N0, and age was shown. Statistical
analysis indicated that these morphological variables
explain 83.6% of the variations in estimated chronological
age. The median of residual errors between the actual
and estimated ages was 120.035 years [interquartile range
(IQR)=1.18 years]
Multiple solutions to a magnetic nonlinear Choquard equation
We consider the stationary nonlinear magnetic Choquard equation
[(-\mathrm{i}\nabla+A(x))^{2}u+V(x)u=(\frac{1}{|x|^{\alpha}}\ast |u|^{p})
|u|^{p-2}u,\quad x\in\mathbb{R}^{N}%] where is a real valued vector
potential, is a real valued scalar potential ,
and . \ We assume that both and are
compatible with the action of some group of linear isometries of
. We establish the existence of multiple complex valued
solutions to this equation which satisfy the symmetry condition where
is a given group homomorphism into the unit
complex numbers.Comment: To appear on ZAM
Role of anisotropy in the F\"orster energy transfer from a semiconductor quantum well to an organic crystalline overlayer
We consider the non-radiative resonant energy transfer from a two-dimensional
Wannier exciton (donor) to a Frenkel exciton of a molecular crystal overlayer
(acceptor). We characterize the effect of the optical anisotropy of the organic
subsystem on this process. Using realistic values of material parameters, we
show that it is possible to change the transfer rate within typically a factor
of two depending on the orientation of the crystalline overlayer. The resonant
matching of donor and acceptor energies is also partly tunable via the organic
crystal orientation.Comment: 6 pages, 8 figure
Carpals and epiphysis of radius and ulna as age indicators
Estimation of skeletal age using radiographic
images is widely used for assessing biological growth in
clinical and auxological studies. The most frequent areas
used for age estimation in children and adolescents are
tooth and wrist/hand, both giving good results with only a
low level of radiation. In particular, ossification of the
carpals shows good agreement with chronological age. This
study of a sample of 150 Italian children and adolescents
aged between 5 and 17 years focused on analyzing the
possible applications of the proportion of carpal area (Ca)
mineralization as a criterion of age estimation. The ratio
between the total area of carpal bones and epiphyses of the
ulna and radius (Bo) andCa was calculated. This ratio (Bo/Ca)
was used for linear regression analysis. The regression model,
describing age as a linear function of the ratio Bo/Ca, yielded
the following equation: Age= 123.253+0.719g+20.610 Bo/Ca,
and explained 83% of the total variance (R2=0.83). The
median of the absolute values of residuals (observed age
minus predicted age) was 0.08 years, with a quartile deviation
of 1.59 years, and a standard error of estimate of 1.19 years
Detection and quantitation analysis of cocaine and metabolites in fixed liver tissue and formalin solutions.
This study reports the results of the detection and quantitation of
cocaine and its metabolites in liver tissues fixed in formalin and in
the formalin solutions in which the same tissues were fixed.
Toxicological analyses were performed on formalin-fixed liver
samples from four cases of death of cocaine abusers and on
formalin solutions (10% buffered, pH 7) in which the samples were
preserved. Analyses carried out at the time of autopsy on body
fluids and tissues allowed identification of cocaine and the
metabolite benzoylecgonine. Liver tissue samples were preserved in formalin solutions for four weeks before analysis. Results only
showed the presence of benzoylecgonine in the studied materials.
The mean levels of recovery of benzoylecgonine in fixed tissues
were 12.31% in liver and 84.47% in formalin from liver. Results
indicated that benzoylecgonine has good stability, even in
biological specimens subjected to chemical fixation
Age estimation in children by measurement of open apices in teeth: an Indian formula.
The aim of this paper is twofold: first, to evaluate
an Indian sample by Cameriere\u2019s European formula; and
second, if this formula turns out to be unsuitable, to study a
specific formula for Indian children. Orthopantomographs
taken from 480 Indian children (227 girls and 253 boys) aged
between 3 and 15 years were analyzed. Following the pilot
study, subjects\u2019 age was modeled as a function of gender (g),
region of country (C), and morphological variables (predictors:
x5, the distance between the inner sides of the open
apex of the second premolar divided by the tooth length;
s \ubc x1 \ufe x2 \ufe x3 \ufe x4 \ufe x5 \ufe x6 \ufe x7, sum of normalized
open apices; N0, the number of teeth with root development
complete. Results showed that all these variables except
gender and second premolar contributed significantly to the
fit so that all were included in the regression model, yielding
the following linear regression formula:
Age \ubc 9:402 0:879 C \ufe 0:663 N0 0:711 s 0:106s N0
where C is a dummy variable equal to 0 for the center or
north of India and 1 for the south. The above equation, with
the variables considered, explained 89.7% (R2=0.897) of
total deviance. The median of the residuals (observed age
minus predicted age) was \u20130.063 years, with an interquartile
range of 1.10 years
Polydimethylsiloxane-LiNbO3 surface acoustic wave micropump devices for fluid control into microchannels.
This paper presents prototypical microfluidic devices made by hybrid microchannels based on piezoelectric LiNbO3 and polydimethylsiloxane. This system enables withdrawing micropumping by acoustic radiation in microchannels. The withdrawing configuration, integrated on chip, is here quantitatively investigated for the first time, and found to be related to the formation and coalescence dynamics of droplets within the microchannel, primed by surface acoustic waves. The growth dynamics of droplets is governed by the water diffusion on LiNbO3, determining the advancement of the fluid front. Observed velocities are up to 2.6 mm s−1 for 30 dBm signals applied to the interdigital transducer, corresponding to tens of nl s−1, and the micropumping dynamics is described by a model taking into account an acoustic power exponentially decaying upon travelling along the microchannel. This straighforward and flexible micropumping approach is particularly promising for the withdrawing of liquids in lab-on-chip devices performing cycling transport of fluids and biochemical reactions
Temperature dependence of the photoluminescence properties of colloidal Cd Se ∕ Zn S core/shell quantum dots embedded in a polystyrene matrix
We report on the temperature dependence of the photoluminescence (PL) spectrum and of the PL relaxation dynamics for colloidal core/shell quantum dots (QDs) embedded in an inert polystyrene matrix. We demonstrate that the confinement energy in the QDs is independent of the temperature. The coupling with both acoustic and optical phonons is also studied. Quantum confinement results in a strong increase of the exciton\char21{}acoustic-phonon coupling constant, up to 71\phantom{\rule{0.3em}{0ex}}\ensuremath{\mu}\mathrm{eV}∕\mathrm{K}, and in a reduced exciton\char21{}longitudinal-optical (LO)-phonon coupling constant, down to , with respect to bulk CdSe. In addition, we demonstrate that the main nonradiative process that limits the quantum efficiency of the QD at room temperature is the thermal escape from the dot assisted by scattering with four LO phonons. Thermally activated trapping in surface states is also observed at low temperature, with an activation energy of about
The measurement of open apices of teeth to test chronological age of over 14-year-olds in living subjects
Age determination in living subjects is a problem of increasing interest in our community, due to the increasing numbers of individuals without
identification papers, who have immigrated illegally or committed crimes, and for whom it is necessary to verify whether they have reached the age
of 14 years in order to be charged legally.
Although the most widespread methods for age estimation refer to skeletal or dental analysis, these methods do present some drawbacks for
identification of the age of 14. The aim of the present study is to discriminate between children who are or are not 14 years of age or older by
measuring the open apices of teeth.
We evaluated the OPGs of 447 persons aged between 12 and 16 years, of Italian, Croatian and Slovenian nationality. For each individual, dental
maturity was estimated using the number of the seven left permanent mandibular teeth with root development complete, and normalized
measurement of the open apices of the third molar.
The results revealed that an individual is considered to be 14 years of age or older if all seven left permanent mandibular teeth have closed apices
and the normalized measurement of open apices of the third molar is lower than 1.1
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