Objective: Low bone quality is a contributing factor to motor vehicle crash (MVC) injury. Quantification of occupant bone mineral density (BMD) is important from an injury causation standpoint. The first aim of this study was to validate a technique for measuring lumbar volumetric BMD (vBMD) from phantomless computed tomography (CT) scans. The second aim was to apply the validated phantomless technique to quantify lumbar vBMD in Crash Injury Research and Engineering Network (CIREN) occupants for correlation with age, fracture incidence, and osteopenia/osteoporosis diagnoses.Methods: Quantitative CT (qCT) and dual-energy X-ray absorptiometry (DXA) were collected prospectively for 50 subjects and used to validate a technique to measure vBMD from 281 phantomless CT scans of CIREN occupants. Hounsfield unit (HU) measurements were collected from the L1–L5 vertebrae, right psoas major muscle, and anterior subcutaneous fat for all subjects and from 3 phantom ports with known mg/cc calcium hydroxyapatite values for the validation group. qCT calibration was accomplished using regressions between the phantom HU and mg/cc values to convert L1–L5 HU values to mg/cc. A phantomless calibration technique was developed where the fat and muscle HU values were linearly regressed against fat (?69 mg/cc) and muscle (77 mg/cc) to establish a conversion for L1–L5 HU measurements to mg/cc. vBMD calculated from qCT versus the phantomless method was compared for the 50 subjects to assess agreement and a mg/cc osteopenia threshold was established using DXA T-scores. CIREN HU measurements were converted to mg/cc using the phantomless technique and the mg/cc osteopenia threshold was used to compare vBMD to age, fracture incidence, and osteopenia comorbidity classifications in CIREN.Results: Linear regression of lumbar vBMD derived from the qCT versus phantomless calibrations showed excellent agreement (R2 = 0.87, P <.0001). A 145 mg/cc threshold for osteopenia was established (sensitivity = 1, specificity = 0.57) and 44 CIREN occupants had vBMD below this threshold. Of these 44 occupants, 64% were not classified as osteopenic in CIREN, but vBMD suggested undiagnosed osteopenia. Age was negatively correlated with vBMD in both sexes (P <.0001) and CIREN occupants with less than 145 mg/cc vBMD sustained an average 1.7 additional rib/sternum fractures (P =.036).Conclusions: Because lumbar vBMD was estimated from phantomless CT scans with accuracy similar to qCT, the phantomless technique can be broadly applied to both prospectively and retrospectively assess patient bone quality for research and clinical studies related to MVCs, falls, and aging. 相似文献
This study examined two conversion methods, M1 and M2, to predict finger/phalange bone lengths based on finger/phalange surface lengths. Forty-one Korean college students (25 males and 16 females) were recruited and their finger/phalange surface lengths, bone lengths and grip strengths were measured using a vernier caliper, an X-ray generator and a double-handle force measurement system, respectively. M1 and M2 were defined as formulas able to estimate finger/phalange bone lengths based on one dimension (i.e., surface hand length) and four finger dimensions (surface finger lengths), respectively. As a result of conversion, the estimation errors by M1 presented mean 1.22?mm, which was smaller than those (1.29?mm) by M2. The bone lengths estimated by M1 (mean r?=?0.81) presented higher correlations with the measured bone lengths than those estimated by M2 (0.79). Thus, the M1 method was recommended in the present study, based on conversion simplicity and accuracy. 相似文献
Objective: The facial region is a commonly fractured site, but the etiology varies widely by country and geographic region. To date, there are no population-based studies of facial fractures in Taiwan.
Methods: We conducted a retrospective study of patients diagnosed with facial fracture and registered in the National Health Insurance Research Database of Taiwan between 1997 and 2011. The epidemiological characteristics of this cohort were analyzed, including the etiology, fracture site, associated injuries, and sex and age distributions.
Results: A total of 6,013 cases were identified that involved facial fractures. Most patients were male (69.8%), aged 18–29 years (35.8%), and had fractures caused by road traffic accidents (RTAs; 55.2%), particularly motorcycle accidents (31.5%). Falls increased in frequency with advancing age, reaching 23.9% among the elderly (age > 65 years). The most common sites of involvement were the malar and maxillary bones (54.0%), but nasal bone fractures were more common among those younger than 18 years.
Conclusion: Most facial injuries in Taiwan occur in young males and typically result from RTAs, particularly involving motorcycles. However, with increasing age, there is an increase in the proportion of facial injuries due to falls. 相似文献
Goal, Scope and Background In this paper, we attempt to elucidate the composition and origin of the orange patina on the surfaces of the West-Porch
of Salisbury Cathedral by comparison to other known patinas: (i) the orange-brown patina on the marble surfaces of the Acropolis
in Athens and the Arch of Titus in Rome whose analyses have shown very high amounts of phosphates, and generally amino acids
from animal-skin glue or other protein binders; (ii) the phosphated patinas which also contain oxalates, found in 1996 on
Catalonian calcareous sandstones and in the calcareous dolomites of the Monastery of Silos, Spain, whose origin is either
the application of calcium caseinate, or egg yolk and animal glue; and (iii) the patinas with only oxalates found in some
of Verona's monuments (St Zeno) and Spanish sites as in the Monastery of Guadalupe and Cuenca cathedral, formed either by
the mineralization of algal filaments or by biological reactions yielding oxalate from yolk egg (added to stone as part of
preservative empirical treatments).
Methods In the winter of 2003, the West-Porch of Salisbury Cathedral received conservation works, but the old patina was not entirely
removed. This fact has allowed us to collect the samples for its study. The IR spectra were registered with a Golden Gate
ATR Mk II system using attenuated total reflectance Fourier transform infrared (ATR/FTIR) spectrometry. Mineral composition
was determined by XRD (Philips PW 1710 spectrometer with Cu tube), whereas major and trace elements analyses were performed
by XRF (Philips PW1480 PW). Microscopy examination was performed on a Leica M655 microscope. Phosphate, oxalate, calcium and
sulphate contents were analysed by usual chemical methods.
Results ATD-FTIR spectra of the Salisbury's patina exhibit peaks at 2361, 2341 and 671 cm–1 (assigned to phosphates); 3410, 1680,
1620, 1122 and 602 cm–1 (assigned to sulphates); and 1447/1437 and 876 cm–1 (attributed to carbonates). The little peaks at
1620 and 798 cm–1 could be assigned to oxalates. XRD and XRF have led to identify the carbonates, phosphates and sulphates
as pertaining to the species dolomite, hydroxyapatite and gypsum, respectively. Oxalates are detected only in small amounts
by chemical analyses but wewellite and weddellite have not been well identified. The interface between the patina and the
calcareous dolomite is very uneven and full of cavities in certain cases, but well-defined and rather smooth in other cases.
In accord with the very small amounts of the oxalates found, remnants of micro-organisms are not detected in the patinas.
Discussion The Salisbury's patina is a composite material formed by particulates and matrix constituents. Regarding the patina particulate,
e.g. animal bones, it is necessary to refer to the apatite phase composition. The bone mineral contains 4–8 wt % of carbonate
in animal body and its presence in the apatite phase is advantageous as it increases the mechanical strength. We think that
FTIR bands at around 1440 and 876 cm–1 arise from vibration of CO32– ions, but not necessarily from the limestone. They could
be attributed to carbonated hydroxyapatite through the substitution of groups PO43– for CO32– in the lattice of hydroxyapatite.
Concerning the matrix and also from the FTIR spectra, the absence of specific bands of the following species: proteins (3350–3225,
1660, 1550–1535, 1270–1230 and 620 cm–1), oils (1778, 1738 and 1051 cm–1), bee waxes (3000, 1470, 720–730 and 1700 cm–1) and
aged egg-yolk (2954, 2920, 2850, 1650, 1549, 1465 and 1240 cm–1) had led us to exclude these usual binders. On the other hand,
the amount of sulphates in the paste that covers the walls of the Salisbury's Cathedral is excessively high (above 20% in
weight) to consider it as a biotransformation product of calcium oxalate from fungal biofilms. Consequently, we must think
that the gypsum found in the samples has a man-made origin (it was deliberately added as part of a protective paste) and that
it is the matrix searched for. Thus, we deduce that the patina of Salisbury's Cathedral is a special stucco made mixing plaster
with powdered bone (the colour of the bones is the same that it exhibits in the patina), low quantities of an uncharacterized
binder (collagen, possibly) and water.
Conclusion We believe that the patina of the Salisbury's Cathedral is a variant of the Greco-Latin empirical protective treatment that
included bone as a hardening material. Nevertheless, we also think that the presence of the bones in the paste could be related
to an aesthetical intention: gaining a warm tone for the original stone through the ochre colour of the bones.
Recommendation and Perspective Our results have been an excuse to contribute to the controversy started at the 80's on the origin of orange-brown patinas
observed on stone surfaces of Greco-Latin and medieval monuments. There are two major theories on provenance: biological vs.
man-made. In Salisbury Cathedral, neither of them has been proven through scientific evidence as yet. Our opinion is that
Salisbury patina can be classified into the man-made group. 相似文献
The factories processing natural phosphates and apatites in Poland release into the atmosphere considerable amounts of fluorine compounds. Fluoride is known to accumulate in the hard tissues of animals and humans. This paper describes the determination of fluoride in mandibles of deer in the years 1982 and 1990. In recent years, the establishments have restricted their output and modernized the technology of phosphate fertilizer production. The fluoride content in jaws has decreased, particularly in those animals having their habitat in the vicinity of the two factories. 相似文献