83 research outputs found

    Hand anthropometry in patients with carpal tunnel syndrome: a case-control study with a matched control group of healthy volunteers

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    Background: The aim of this study was to perform anthropometrical measure- ments of patients’ hands with carpal tunnel syndrome (CTS) in order to evaluate if there is a correlation between CTS occurrence and hand features regarding sexual dimorphism, age and physical activity.  Materials and methods: Study sample consisted of 48 patients (33 females) and control group included 80 healthy volunteers (58 females) with no history of CTS. The following measurements were performed: the wrist circumference, length of the hand, the hand’s width, width of the wrist, thickness of the wrist, height of the hypothenar and thenar, length of the arm and forearm, circumference of the proximal phalanges and width of the digits; as well as several indexes were calculated i.e.: body mass index (BMI), shape index, digit index, wrist index, hand length/height ratio (HLH-ratio) and hand length/upper limb length ratio (HLULL-ratio).  Results: Correlation coincidences were analysed between circumferences within the hand, palm and body weight. All parameters except fingers were correlated with body weight in either gender in both groups (p < 0.05; r = 0.40–0.80); Furthermore, width of the hand was correlated with body height (p < 0.001; r = 0.56–0.71). Mean values of wrist index for CTS patients were: males: 0.8, females: 0.74 (significantly higher than in healthy individuals and indicating square shape); shape index: males 76.5, females 75.8; digit index: males 55.7, females 56.5. The calculated HLH-ratio in CTS group was: males 10.6, females 10.9; HLULL-ratio: males 23.6, females 24.9 and they did not differ significantly from healthy volunteers. Almost 90.0% of females with diagnosed CTS have BMI > 25.0 kg/m2.  Conclusions: There are significant differences in morphometrical features of the upper limbs between CTS patients and healthy individuals. Hands of patients with CTS are more massive and with ‘plumb’ fingers and square shape of the wrist. Furthermore, higher BMI values were confirmed to be predisposing factors in CTS occurrence.

    Rare earth oxycarbonates as a material class for chemoresistive CO2 gas sensors

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    AbstractIn this work we compare the CO2 gas sensing properties of two new materials synthesized from rare earth hydroxide (La(OH)3,Pr(OH)3) precursors, with the already reported ones for neodymium oxycarbonate, which was synthesized from the corresponding Nd(OH)3 precursor. In-situ XRD measurements show that by following similar thermal treatment, praseodymium hydroxide is transforming to the metal oxide while lanthanum hydroxide forms an oxycarbonate, like in the case of neodymium. The chemoresistive effects we found for the lanthanum oxycarbonate were even higher than the ones recorded for the neodymium oxycarbonate; for the praseodymium metal oxide we could not find any CO2 sensitivity. Accordingly, we think that the condition for CO2 sensing is the formation of the rare earth oxycarbonate

    The Evolved Red Stellar Contents of the Sculptor Group Galaxies NGC55, NGC300, and NGC7793

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    Deep J, H, and K images are used to probe the evolved stellar contents in the central regions of the Sculptor group galaxies NGC55, NGC300, and NGC7793. The brightest stars are massive red supergiants (RSGs) with K ~ 15 - 15.5. The peak RSG brightness is constant to within ~0.5 mag in K, suggesting that NGC55, NGC300, and NGC7793 are at comparable distances. Comparisons with bright RSGs in the Magellanic Clouds indicate that the difference in distance modulus with respect to the LMC is = 7.5. A rich population of asymptotic giant branch (AGB) stars, which isochrones indicate have ages between 0.1 and 10 Gyr, dominates the (K, J-K) color-magnitude diagram (CMD) of each galaxy. The detection of significant numbers of AGB stars with ages near 10 Gyr indicates that the disks of these galaxies contain an underlying old population. The CMDs and luminosity functions reveal significant galaxy-to-galaxy variations in stellar content. Star-forming activity in the central arcmin of NGC300 has been suppressed for the past Gyr with respect to disk fields at larger radii. Nevertheless, comparisons between fields within each galaxy indicate that star-forming activity during intermediate epochs was coherent on spatial scales of a kpc or more. A large cluster of stars, which isochrones suggest has an age near 100 Myr, is seen in one of the NGC55 fields. The luminosity function of the brightest stars in this cluster is flat, as expected if a linear luminosity-core mass relation is present.Comment: 30 pages, including 13 figure

    Ultrasound-guided topographic anatomy of the medial calcaneal branches of the tibial nerve

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    Background: The purpose of this study was to evaluate the topographic anatomy of the tibial nerve and its medial calcaneal branches in relation to the tip of the medial malleolus and to the posterior superior tip of the calcaneal tuberosity using the ultrasound examination and to verify its preoperative usefulness in surgical treatment. Materials and methods: Bilateral ultrasound examination was performed on 30 volunteers and the location of the tibial nerve bifurcation and medial calcaneal branches origin were measured. Medial calcaneal branches were analysed in reference to the amount and their respective nerves of origin. Results: In 77% of cases, tibial nerve bifurcation occurred below the tip of the medial malleolus with the average distance of 5.9 mm and in 48% of cases above the posterior superior tip of the calcaneal tuberosity with the average distance of 2.7 mm. In 73% of cases medial calcaneal branches occurred as a single branch originating from the tibial nerve (60%). The average distance of the first, second and third medial calcaneal branch was accordingly 9.3 mm above, 9.5 mm below and 11.6 mm below the tip of the medial malleolus and 17.7 mm above, 1.6 mm below and 4 mm below the posterior superior tip of the calcaneal tuberosity. Conclusions: As the tibial nerve and its branches present a huge variability in the medial ankle area, in order to prevent the iatrogenic injuries, the preoperative or intraoperative ultrasound assessment (sonosurgery) of its localisation should be introduced into the clinic

    The terminal branch of the posterior interosseous nerve: an anatomic and histologic study

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    Background: The aim of this study was to evaluate the terminal branch of the posterior interosseous nerve (PIN) by anatomically and histologically assessing the number, dimension, and area of its individual fascicles, by determining the dimension and area of the whole nerve itself, and by calculating the nerve density ratio (ratio of the sum of the areas of individual fascicles to the area of the whole nerve) of the terminal branch of the PIN. Materials and methods: Twenty-eight terminal branches of the PIN nerve samples were collected from patients undergoing partial denervation of the wrist. The nerve samples were fixed in 10% buffered formalin and stained with haematoxylin and eosin to visualise their nerve bundles. Quantitative analysis of individual fascicles and the whole nerve itself were carried out. Results: Ten nerve samples (35.7%) had one single fascicle (group 1) while the remaining 18 nerve samples (64.3%) contained 2–9 fascicles (group 2). The difference in the sum of the areas of individual fascicles between the two groups did not constitute a statistical difference. Statistically significant between-group differences (p < 0.05) were seen in the area of whole nerve, the ratio of fascicle area to the nerve cross-sectional area and the cross-section maximum nerve length and width. Conclusions: The number of nerve fascicles in the terminal branch of the PIN does not affect the overall size of the nerve. The majority of the volume of multi-fascicle nerves, therefore, primarily consists of the internal perineurium. However, due to the low number of nerves, this question cannot be clearly answered. This sets a further direction for further research on a larger group

    Correcting for the Effects of Interstellar Extinction

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    This paper addresses the issue of how best to correct astronomical data for the wavelength-dependent effects of Galactic interstellar extinction. The main general features of extinction from the IR through the UV are reviewed, along with the nature of observed spatial variations. The enormous range of extinction properties found in the Galaxy, particularly in the UV spectral region, is illustrated. Fortunately, there are some tight constraints on the wavelength dependence of extinction and some general correlations between extinction curve shape and interstellar environment. These relationships provide some guidance for correcting data for the effects of extinction. Several strategies for dereddening are discussed along with estimates of the uncertainties inherent in each method. In the Appendix, a new derivation of the wavelength dependence of an average Galactic extinction curve from the IR through the UV is presented, along with a new estimate of how this extinction law varies with the parameter R = A(V)/E(B-V). These curves represent the true monochromatic wavelength dependence of extinction and, as such, are suitable for dereddening IR--UV spectrophotometric data of any resolution, and can be used to derive extinction relations for any photometry system.Comment: To appear in PASP (January 1999) 14 pages including 4 pages of figures Uses emulateapj style. PASP, in press (January 1999

    Extinction Curves, Distances, and Clumpiness of Diffuse Interstellar Dust Clouds

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    We present CCD photometry in UBVRI of several thousand Galactic field stars in four large (>1 degree^2) regions centered on diffuse interstellar dust clouds, commonly referred to as ``cirrus'' clouds (with optical depth A_V less than unity). Our goal in studying these stars is to investigate the properties of the cirrus clouds. A comparison of the observed stellar surface density between on-cloud and off-cloud regions as a function of apparent magnitude in each of the five bands effectively yields a measure of the extinction through each cloud. For two of the cirrus clouds, this method is used to derive UBVRI star counts-based extinction curves, and U-band counts are used to place constraints on the cloud distance. The color distribution of stars and their location in (U-B, B-V) and (B-V, V-I) color-color space are analyzed in order to determine the amount of selective extinction (reddening) caused by the cirrus. The color excesses, A_lambda-A_V, derived from stellar color histogram offsets for the four clouds, are better fit by a reddening law that rises steeply towards short wavelengths [R_V==A_V/E(B-V)<=2] than by the standard law (R_V=3.1). This may be indicative of a higher-than-average abundance of small dust grains relative to larger grains in diffuse cirrus clouds. The shape of the counts-based effective extinction curve and a comparison of different estimates of the dust optical depth (extinction optical depth derived from background star counts/colors; emission optical depth derived from far infrared measurements), are used to measure the degree of clumpiness in clouds. The set of techniques explored in this paper can be readily adapted to the Sloan Digital Sky Survey data set in order to carry out a systematic, large-scale study of cirrus clouds.Comment: 22 pages, 13 figures (postscript, gif, jpg). Accepted for publication in the Astronomical Journal, scheduled for the May 1999 issue. Full resolution postscript versions of all figures are available at http://www.ucolick.org/~arpad

    The potential of operando XAFS for determining the role and structure of noble metal additives in metal oxide based gas sensors

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    Noble metal additives significantly improve the performance of SnO2 based sensors. Recently, it has been found that X-ray absorption spectroscopy is an excellent tool to identify their structure under sensing conditions, despite of the low concentrations and the rather thin (50 ÎŒm) and highly porous layers. For this purpose a new in situ approach has been established and here we highlight the potential with an overview on the results of Pd-, Pt-, and Au-additives in SnO2-based sensors at work. Emphasis was laid on recording the structure (by XANES and EXAFS) and performance at the same time. In contrast to earlier studies, Pd- and Pt-additives were observed to be in oxidized and finely dispersed state under sensing conditions excluding a spillover from metallic noble metal particles. However, Au was mainly present as metallic particles in the sensing SnO2-layer. For the Pt- and Au-doped SnO2-layers high energy-resolved fluorescence detected X-ray absorption spectra (HERFD-XAS) were recorded not only to minimize the lifetime-broadening but also to eliminate the Au- and Pt-fluorescence effectively and to record range-extended EXAFS

    An Analysis of the Shapes of Interstellar Extinction Curves. V. The IR-Through-UV Curve Morphology

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    We study the IR-through-UV interstellar extinction curves towards 328 Galactic B and late-O stars. We use a new technique which employs stellar atmosphere models in lieu of unreddened "standard" stars. This technique is capable of virtually eliminating spectral mismatch errors in the curves. It also allows a quantitative assessment of the errors and enables a rigorous testing of the significance of relationships between various curve parameters, regardless of whether their uncertainties are correlated. Analysis of the curves gives the following results: (1) In accord with our previous findings, the central position of the 2175 A extinction bump is mildly variable, its width is highly variable, and the two variations are unrelated. (2) Strong correlations are found among some extinction properties within the UV region, and within the IR region. (3) With the exception of a few curves with extreme (i.e., large) values of R(V), the UV and IR portions of Galactic extinction curves are not correlated with each other. (4) The large sightline-to-sightline variation seen in our sample implies that any average Galactic extinction curve will always reflect the biases of its parent sample. (5) The use of an average curve to deredden a spectral energy distribution (SED) will result in significant errors, and a realistic error budget for the dereddened SED must include the observed variance of Galactic curves. While the observed large sightline-to-sightline variations, and the lack of correlation among the various features of the curves, make it difficult to meaningfully characterize average extinction properties, they demonstrate that extinction curves respond sensitively to local conditions. Thus, each curve contains potentially unique information about the grains along its sightline.Comment: To appear in the Astrophysical Journal, Part 1, July 1, 2007. Figures and Tables which will appear only in the electronic version of the Journal can be obtained via anonymous ftp from ftp://ftp.astronomy.villanova.edu . After logging in, change directories to "fitz/FMV_EXTINCTION". A README file describes the various files present in the director

    The divided zygoma: a meta-analysis of its prevalence with a review of the literature

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    Background: Divided zygoma (DZ) is an important structure in the midfacial region. The anatomy of DZ is poorly researched, but knowledge about this entity could be useful during posttraumatic facial reconstructions. The aim of this study was to estimate the prevalence and anatomy of DZ in different regions around the world. Therefore, the authors performed a meta-analysis, including all studies that report extractable data on the DZ. Materials and methods: The main online medical databases such as PubMed, EBSCO, ScienceDirect, Web of Science, SciELO, BIOSIS, Current Content Connect, Korean Journal Database and Russian Citation Index, were utilized to gather all studies on anatomical characteristics, prevalence, symmetry, and a number of divisions of zygomatic bone. Results: A total of 20 studies were included in this meta-analysis. Data were grouped and analyzed in 5 categories: (1) prevalence of DZ bone, (2) prevalence of DZ skulls, (3) gender prevalence of DZ with sides, (4) divisions of zygomatic bone, (5) symmetry of DZ. Conclusion: In conclusion, the authors of the present study believe that this is this study can be considered and up-to-date meta-analysis regarding the prevalence, divisions, and symmetricity of the DZ. The data provided by the present study may be useful information for physicians in recognizing the DZ of the fracture and may be important information during zygomatic bone osteotomy. Detailed anatomical knowledge of the midfacial region can prevent surgical complications when operating in this area
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