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Numerical Methods and Computational Tools
Published in Raj P. Chhabra, CRC Handbook of Thermal Engineering Second Edition, 2017
Atul Sharma, Salil S. Kulkarni, K. Hrisheekesh, Amit Agrawal, Shyamprasad Karagadde, Amitabh Bhattacharya, Rajneesh Bhardwaj
Bhardwaj et al. [8] simulated the propagation of the blast wave in 3D coordinates to obtain the transient flow fields and pressure loading on the human eye. The flow fields in the sagittal plane are shown in Figure 5.6.13a, and the extensive reflections of the blast wave by the nasal and brow ridges are also shown in this figure. The blast wave reflections also produced an asymmetric pressure loading on the eye (Figure 5.6.13b) that was higher, close to the nasal bone than the zygomatic bones. This study also predicted possible eye injuries and associated injury risks using the calculated intraocular pressure (IOP) and von Mises stress in the sclera.
Obstetrics and gynaecology
Published in David A Lisle, Imaging for Students, 2012
An accurate risk assessment for fetal aneuploidy is calculated based on: Maternal ageNuchal thicknessPresence or absence of the fetal nasal boneMaternal levels of β-hCG and pregnancy-associated plasma protein A (PAPP-A).
Dental Radiography
Published in Paolo Russo, Handbook of X-ray Imaging, 2017
Using larger area detectors (ca. 7 × 5 cm2) occlusal radiographs are obtained by placing the detector between the occlusal tooth surfaces. The patient is instructed to slightly close his/her mouth to gently hold the detector in place. Care must be exercised that the patient does not force his/her bite, since this likely would damage the detector. Both film and storage phosphors are used for acquisition of occlusal radiographs. Unfortunately, however, to date solid-state detectors are not yet available, simply due to their very high costs in the required size. Depending on the region under investigation, the receptor may be placed either with its longitudinal axis parallel to the midsagittal plane or perpendicular to it. In relation to periapical and bitewing radiographs, occlusal radiographs are far less common and acquired only for special purposes. Their main indication is to obtain a view from a direction roughly orthogonally to the occlusal plane. Consequently, maxillary occlusal radiographs show the hard palate roughly back to the second molar. The posterior occlusal may even reach back to the wisdom teeth. Here, the angle between the detector and the central X-ray is ca. 60° to 70°. A more orthogonal orientation would interfere with the frontal bone of the skull, which would then be superimposed over the hard palate, thereby disguising the structures of interest. For the less frequently used posterior maxillary occlusal, the X-ray should be orientated even more obliquely (around 75°). The patient is seated with the occlusal plane roughly parallel to the horizontal plane. The dental X-ray cone is placed with its aperture centered on the nasal bone and the central X-ray orientated roughly onto the sagittal midline of the patient in the region of the first upper molar (Figure 22.18).
Force and velocity of impact during upper limb strikes in combat sports: a systematic review and meta-analysis
Published in Sports Biomechanics, 2023
Václav Beránek, Petr Votápek, Petr Stastny
Strikes with a certain level of Fmean or Fmax can have high potential for a risk of injury, which some authors have evaluated in connection with boxing and taekwondo systems (Svoboda et al., 2016; Walilko et al., 2005). This becomes even more important if the strike targets the face, where biomechanical tolerance of different regions of the facial bones has been reported (Adamec et al., 2013): the nasal bone (os nasale) has the lowest tolerance (0.5 kN), followed by the maxilla (0.7–1.5 kN), the os zygomaticum (1.0 kN), the mandibula (1.4 kN), the lateral region of the skull (2.0–3.6 kN), the temporoparietal region (2.5–5.2 kN), the frontal region (4.0–6.2 kN) and the occipital region (12.5 kN). When comparing the values of the highest Fmean of straight punches with the contact forces required for bone fracture, fractures can be caused in six regions of the skull. When comparing the Fmax (Table 1), fractures can be caused in seven regions of the skull. In total, four studies reported values that approached or exceeded the tolerance of most facial bones (5 kN) (Atha et al., 1985; Dyson et al., 2005; Walilko et al., 2005; Pierce et al., 2006). On the other hand, high-impact strikes can cause injury risks for the attacker and may cause the attacker to be injured (Kowalczuk et al., 2009; Shafran-Tikva et al., 2017), according to Newton’s third law.
Nuchal Translucency Thickness Measurement in Fetal Ultrasound Images to Analyze Down Syndrome
Published in IETE Journal of Research, 2021
Mary Christeena Thomas, Sridhar P. Arjunan, Rekha Viswanathan
Down syndrome (DS), or trisomy 21 is a chromosomal abnormality first discovered by John Langdon Down [1] in the year 1866. DS is occurred because of the additional copy of chromosome 21 [2]. Each year, 1 in 1000 babies are born with DS, and advanced maternal age can increase the risk of having a baby with DS [3]. Ultrasonography [4] is used for the detection and assessment of fetuses because of its non-invasive nature, economical, and constant enhancement in the quality of the image. DS can be identified before birth (prenatally) or after birth (postnatally). Prenatal screening includes biochemical serum [5] (Beta-HCG and Papp-A), and an ultrasound (US). Amniocentesis and Chorionic villus sampling [6,7] are the invasive diagnostic tests to detect DS which can lead to miscarriage and fetal injury. DS is likely to be associated with a blood test, and markers like Nuchal translucency (NT) and Nasal Bone (NB) are seen in the ultrasound scan during the first and second trimester of pregnancy. Combined Maternal age [8], biochemical serum, and sonographic markers such as NT and NB [9] give a better detection rate.
Critical-Size Alveolar Defect Treatment via TGF-ß3 and BMP-2 Releasing Hybrid Constructs
Published in Journal of Biomaterials Science, Polymer Edition, 2019
Aybüke Garipcan, Petek Korkusuz, Elif Bilgic, Halil M. Aydin, Eda Ozturk, Ilyas Inci, Asya Ozkizilcik, K. Kamile Ozturk, Erhan Piskin, Ibrahim Vargel
Male Wistar-Albino rats weighing between 350 to 500 g were caged in the Hacettepe University Animal Experiments Laboratory and fed ad libitum in a 12-hours light/dark cycle. All of the experimental procedures were approved by Animal Experimentations Ethics Board of Hacettepe University, (Hacettepe University Ethical Board Permission No:2010/7). An intraperitoneal injection of ketamin/xylazin anesthesia was performed. Anesthetized rats were placed in supine. One centimeter-long full-thickness cut was made in the gingival mucosa layer between maxillary first molar and central incisor. Dentoalveolar mucoperiosteal flap was removed to expose alveolar bone. As reported in the literature, critical-size alveolar bone defects (7x4x3 mm) were made by thin drilling of alveolar bone towards right nasal bone (Fig 1) [48, 49]. Iliac bone was chosen as autograft donor site due to histomorphological similarities of the bones and mostly preference of the same method in clinical applications.