angular measurements
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2022 ◽  
Vol 38 (3) ◽  
Author(s):  
Gülnihal Deniz ◽  
Ahmet Kavakli ◽  
Murat Kucukukur ◽  
Evren Kose ◽  
Ilgin Karaca

Objectives: To investigate the diversity and average values of bifurcation angles in a large population to help develop new methods. Methods: One thousand five individuals (504 females, 501 male) who visited the Cardiology Polyclinic of Fırat University Hospital with the complaint of chest pain between 2010 and 2015 were evaluated retrospectively. Bifurcation angle measurements between LMCA-CX, CX-LAD, LMCA-LAD, CX-OM1, CX-OM2, LAD-D1, LAD-D2, RCA-RMD, RCA-RVD and PDA-PL were evaluated in all cases. Results: Bifurcation angles between LMCA-LAD, LMCA-Cx and LAD-Cx branches with “> 90 wide angle bifurcations”, and Cx-OM1, Cx-OM2, LAD-D1, LAD-D2, RCA-RMD and PDA-PL with “<70 Y type bifurcation angle” were found to be high in male and female individuals. The RCA-RVD in female individuals was “<70 Y-type bifurcation” in 14 (2.8%) people, “> 70-90 T-type bifurcation” in 209 (41.5%) people, and “> 90 wide angle bifurcation” in 281 (55.8%) people. Results for male subjects were compatible with this. The correlations of all angles were examined. Robust positive correlations (p≤0.001) were found for the angular measurements between the main branches and the side branches (Cx-OM1, Cx-OM2, LAD-D1, LAD-D2 and RCA-RMD, PDA-PL). Conclusion: With the help of developing technology, we believe that all this coronary angiography data will guide bifurcation stent techniques, which are essential alternatives to bypass. doi: https://doi.org/10.12669/pjms.38.3.4782 How to cite this:Deniz G, Kavakli A, Kucukukur M, Kose E, Karaca I. Evaluation of major coronary artery Bifurcation angles with digital angiography: A detailed study of prevalence in the Upper Euphrates Basin. Pak J Med Sci. 2022;38(3):---------.  doi: https://doi.org/10.12669/pjms.38.3.4782 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


2022 ◽  
Vol 11 ◽  
pp. 279-287
Author(s):  
Esra Genc ◽  
S. Kutalmış Buyuk

Objectives: Maxillary impacted canines have an important place in orthodontics for the reason of being a common anomaly and its treatment is time consuming and difficult. The aim of this study was to investigate the mandibular indexes and cephalometric parameters in adolescents with impacted maxillary canines. Materials and Methods: The radiographs of 4026 patients aged 12–19 years old were scanned and a total of 155 patients were included in the study. Subjects were divided into three groups according to the permanent maxillary canines: Bilateral impacted canine (BIC) (52 subjects; mean age 15.02 ± 1.74 years), unilaterally impacted canine (UIC) (51 subjects; mean age 14.89 ± 1.39 years), and the control (52 subjects; mean age 14.84 ± 1.65 years) groups. Skeletal, soft tissue and dental measurements were performed on cephalometric radiographs. Mandibular index analyzes including the panoramic mandibular index (PMI), mental index (MI), antegonial index (AI), and gonial index (GI) measurements and also angular measurements of impacted maxillary canines were performed on panoramic radiographs. Data were analyzed statistically and P < 0.05 was considered significant. Results: Maxillary skeletal and dental measurements showed retrusive positioned maxillary dental arch in the sagittal direction in the impacted canine groups (P < 0.05). PMI and MI values were greater in the BIC and UIC groups than in control group (P < 0.05). There was no statistically significant difference in AI value among groups (P < 0.05). GI value of BIC group was found statistically lower than other groups (P < 0.05). Conclusion: Individuals with impacted maxillary canines have more retrusive maxillary dental arch and soft-tissue components. Furthermore, mandibular cortex was thicker in subjects with impacted maxillary canine than individuals with not and clinicians should keep in mind this when examine the panoramic radiographs in terms of early diagnosis of impacted maxillary canine teeth.


2021 ◽  
Vol 20 ◽  
pp. 97-107
Author(s):  
Piotr Banasik ◽  
Władysław Góral

The astronomical knowledge on the disc has been coded on two planes: horizontal and meridian. The range of sunrise and sunset directions during the year has been described on the horizontal plane. In turn, on the meridian (vertical) plane, the range of changes in the horizontal height and declination of the Sun in the upper culmination during the year and the Moon in its 18.61-year cycle were described. The relationships between the latitude of the place of observation, the horizontal height of the celestial body and its declination were described by means of geometric constructions. The presented article is a continuation of two publications [1] and [2], which describe the decryption of the Nebra disc. These publications were based on the interpretation of the results of angular measurements, made using a protractor with a scale of 0.5 degrees, without the use of a computer. The presented publication is based on a digital disc image obtained by means of its digitization. The obtained data was used for further calculations based on analytical geometry and graphic programs. This allowed to obtain results in a linear measure with a precision of less than 1 mm. PRECYZJA DYSKU Z NEBRY W ASPEKCIE ASTRONOMICZNYM I GEOMETRYCZNYM Wiedza astronomiczna na dysku została zakodowana na dwóch płaszczyznach: horyzontalnej i południkowej. Na płaszczyźnie horyzontalnej (poziomej) opisano zakres kierunków wschodu i zachodu Słońca w ciągu roku. Z kolei na płaszczyźnie południkowej (pionowej) opisano zakres zmiany wysokości horyzontalnej i deklinacji Słońca w kulminacji górnej w ciągu roku oraz Księżyca w jego 18,61-rocznym cyklu. Za pomocą konstrukcji geometrycznych opisano związki między szerokością geograficzną miejsca obserwacji, wysokością horyzontalną ciała niebieskiego i jego deklinacją. Prezentowany artykuł jest kontynuacją dwóch publikacji: [1], [2], w których opisano deszyfrację dysku z Nebry. Publikacje te były oparte na interpretacji wyników pomiarów kątowych, wykonanych za pomocą kątomierza o podziałce 0,5 stopnia, bez użycia komputera. Prezentowana publikacja bazuje na cyfrowym obrazie dysku, uzyskanym za pomocą jego digitalizacji. Uzyskane dane wykorzystano do dalszych obliczeń opartych na geometrii analitycznej oraz programach graficznych.


2021 ◽  
Vol 7 (12) ◽  
pp. 110739-11078
Author(s):  
Ligianne Landim Sampaio ◽  
Natália Muniz Santos ◽  
Nathállia Manuela Luna Lacerda ◽  
Paulo Moura Leal Neto ◽  
Raisla Luana Bezerra de Aquino ◽  
...  
Keyword(s):  

2021 ◽  
Vol 94, 2021 (94) ◽  
pp. 20-28
Author(s):  
Mykhailo Fys ◽  
◽  
Volodymyr Litynskyi ◽  
Anatolii Vivat ◽  
Svyatoslav Litynskyi ◽  
...  

The aim. The study of formulas determination of the point coordinates by the inverse linear-angular intersection method. Previously, we investigated the possibility of using electronic total stations to control the geometric parameters of industrial buildings. The applied application of electronic total stations for high-precision measurements has been investigated as well. [Vivat, 2018]. The formula for optimal use of the device with certain accuracy characteristics relative to the measured basis is analytically proved and derived [Litynskyi, 2014]. Measurements on the basis of the II category are performed and theoretical calculations are confirmed. The possibility of achieving high accuracy in determining the segment by the method of linear-angular measurements is shown [Litynsky, 2015]. The influence of the angle value on the accuracy of determining the coordinates by the sine theorem is investigated and the possibility of optimizing the determination of coordinates by the method of inverse linear-angular serif by the formulas of cosines and sines is investigated [Litynskyi, 2019]. Method. Establishing a mathematical interconnection between measured values (distances and angles) with the required (flat coordinates of a point), differentiation and finding the minima of functions. Results.There were five formulas selected, of which six combinations had been created to calculate the increments of coordinates and to estimate their accuracy. Numerical experiments show that neither method has a significant advantage, which is supported by the results presented in the graphs and tables. It is worth noting one feature of the second method - in which it is possible to determine the increments of coordinates with an accuracy that exceeds the accuracy of measuring the sides. The possibility of optimizing the coordinate increments determination due to the choice of calculation formulas is considered. The possibility of increasing the accuracy of determination of the coordinates increments using different calculation formulas is researched. Consequently, it is suggested to optimize the choice of calculation formulas depending on the position of the desired point. The results of these studies can be used to create electronic total station or laser tracker application software in order to improve the accuracy of coordinate determination.


2021 ◽  
Vol 56 ◽  
pp. 71-82
Author(s):  
I. Z. Indutnyi ◽  

Detailed studies of the efficiency of excitation of surface plasmon-polaritons (SPP) on aluminum gratings with a period a = 694 nm, which exceeds the incident wavelength of λ = 632,8 nm, have been carried out. The gratings relief depth (h) range was 6–135 nm. Research samples were formed on As40S30Se30 chalcogenide photoresist films using interference lithography and vacuum thermal deposition of an opaque aluminum layer about 80 nm thick. An atomic force microscope was used to determine the groove profile shape and the grating relief depth. The study of the SPP excitation features was carried out on a stand mounted on the basis of a G5M goniometer and an FS-5 Fedorov stage by measuring the angular dependences of the intensity of specularly reflected and diffracted p-polarized radiation of He-Ne laser. When determining the SPP excitation efficiency, the resonance values of both specular reflection and reflection in the -1st DO were taken into account. It was found that the dependence of the integral plasmon absorption on the grating modulation depth (h/a) is described by a somewhat asymmetric curve with a wide maximum, the position of which corresponds to an h/a value of about 0.07 and a half-width of about 0.123. This allows to excite SPP with an efficiency ≥ 80% of the maximum value on the gratings with the 0,05-0,105 h/a range. The half-width of the plasmon minimum of the reflection in the -1st DO is less than in the specular reflection, which can increase sensitivity of sensor devices when registering the shift of the minimum from angular measurements. The dependence of the half-width of the SPP reflection minima on the grating modulation depth is close to quadratic. In the investigated h/a range (from 0.009 to 0.194), the maximum dynamic range of the reflection coefficient is two orders of magnitude and is achieved in specular reflection for gratings with h/a ≈ 0.075.


Author(s):  
O. Kuznietsov ◽  
O. Kolomiitsev ◽  
S. Yarovyy ◽  
R. Oliinyk ◽  
Y. Zhivetc

Radars with a phased array antenna (PAA) which performs multi-channel radar signal reception are effective means of obtaining radar information about air objects in difficult conditions of air and jamming environment. Radar surveillance for radars with PAA is accompanied by a significant negative effect of tropospheric inhomogeneity, which causes a decrease in the accuracy of measurements of azimuth angles and air object‟s position due to fluctuations of the phase front of the received wave reflected from an air object. According to the results of research, the hypothesis of a normal distribution law of these fluctuations is accepted. The paper presents the results of estimating the root mean square errors of measuring the angular coordinates of the air object, which occur if the fluctuations of the phase front of the received signal‟s wave are not taken into account and analyzes the possibility of reducing such errors when the fluctuations are considered. The possibility of optimizing the angular measurements of air objects in digital radars with PAA is shown, which consists in taking into account the fluctuations of the phase front of the received signal in the algorithm of discrete (fast) Fourier transform, which is widely used to provide spatial measurements in modern digital radar stations. The results of previous studies were generalized, which makes it possible to evaluate the possibility of increasing the accuracy of angular measurements of air objects during multichannel reception of a radar signal in difficult conditions of radar operation.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Saher Abu-Leil ◽  
Asaf Weisman ◽  
Yizhar Floman ◽  
Fabio Galbusera ◽  
Youssef Masharawi

Abstract Background Although Degenerative Spondylolisthesis (DS) is a common osseous dysfunction, very few studies have examined the bony morphology of lumbar the neural arch in the population afflicted with DS. Therefore, this study aimed to characterize the neural arch (NA) morphology along the entire lumbar spine in individuals with degenerative spondylolisthesis (DS) and compare them to healthy controls. Methods One hundred CTs from a database of 500 lumbar CTs of spondylolisthesis were selected. We excluded vertebral fractures, non-L4-L5 slips, previous surgeries, vertebral spondyloarthropathies, and scoliosis. Scans were divided into a study group of 50 individuals with single-level DS (grades 1–2) at L4–5 (25 males and 25 females), and an age-sex matched control group of 50 individuals. Linear and angular measurements from all lumbar segments included: vertebral canals, intervertebral foramens, pedicles, and articular facets. Results Compared with the controls, all individuals with DS had greater pedicle dimensions in the lower lumbar segments (∆ = 1 mm–2.14 mm) and shorter intervertebral foramens in all the lumbar segments (∆range:1.85 mm–3.94 mm). In DS females, the lower lumbar facets were mostly wider (∆ = 1.73–2.86 mm) and more sagittally-oriented (∆10°) than the controls. Greater prevalence of grade-3 facet arthrosis was found only in the DS population (DS = 40–90%,controls = 16.7–66.7%). In DS males, degenerated facets were observed along the entire lumbar spine (L1-S1), whereas, in DS females, the facets were observed mainly in the lower lumbar segments (L4-S1). Individuals with DS have shorter intervertebral foramens and greater pedicle dimensions compared with controls. Conclusions Females with DS have wider articular facets, more sagittally-oriented facets, and excessively degenerated facets than the controls. This unique NA shape may further clarify DS’s pathophysiology and explain its greater prevalence in females compared to males.


2021 ◽  
Vol 7 (11) ◽  
pp. 109691-109700
Author(s):  
Ligianne Landim Sampaio ◽  
Natália Muniz Santos ◽  
Nathállia Manuela Luna Lacerda ◽  
Paulo Moura Leal Neto ◽  
Raisla Luana Bezerra De Aquino ◽  
...  
Keyword(s):  

2021 ◽  
pp. 105566562110531
Author(s):  
Natália Cristina Ruy Carneiro ◽  
Lucas Guimarães Abreu ◽  
Roselaine Moreira Coelho Milagres ◽  
Tania Mara Pimenta Amaral ◽  
Carlos Flores-Mir ◽  
...  

Objective The aim was to assess craniofacial features through facial anthropometric and lateral cephalometry measurements of individuals with mucopolysaccharidosis (MPS) and compare them with individuals without MPS. Design Cross-sectional study. Patients A total of 14 individuals with MPS and 28 non-MPS age- and sex-matched were enrolled in this study. Methods A clinical facial analysis to evaluate the soft tissues and cephalometric analysis that comprised linear and angular measurements were performed. The calculation of the method error suggested no systematic errors ( p > .05). Random errors for linear and angular measurements were low (less than 0.5° and 1.6 mm). Chi-square test and independent t-test were performed. Results Most individuals with MPS were dolichofacial, presented altered facial proportions with an increased anterior lower facial height (ALFH) and lip incompetence (all p < .05), when compared with non-MPS individuals. Six angular measurements (1s.Na, 1s.NB, FMA, IMPA, AFI, and Po.Or_Go.Me; all p < .05) were significantly increased among individuals with MPS, and two (1s.1i and Ba.N-Ptm.Gn, all p < .05) were significantly decreased among them. Four linear measurements were significantly increased among individuals with MPS (1s-NA, 1i-NB, S-UL, and S-LL; all p < .05) and five (PogN-Perp, Co-A, Co-Gn, Nfa-Nfp, and overbite; all p < .05) were significantly decreased among them. Conclusion In summary, most individuals with MPS were dolichofacial with increased ALFH. Proclined upper and lower incisors, reduced nasopharyngeal space, and reduced overbite was also noted.


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