Dimensional Measurements Research Articles

Potential of natural fiber based on plant characteristics

Natural fiber is one of the prospective non-timber forest products that contribute to the augmentation of a nation’s foreign exchange within the forestry industry. The objective of this research is to ascertain the distinguishing features of several species of plants that produce natural fiber, and to evaluate the prospective applications of these fibers. The study approach commences by conducting tests on the physical qualities, followed by analysing the chemical components with the established TAPPI method. Additionally, tests are conducted to assess dimensional analyses and fiber variants. The result indicated that the examination of the physical characteristics of the specimens, namely their specific gravity and water content, yielded a strong classification falling within the range of II-IV. The study of chemical constituents, including extractives, lignin, and cellulose, across all samples yielded a range of 1.27% to 7.64%, 15.88% to 36.55%, and 24.63% to 68.32%, respectively. Similarly, the findings from the analysis of fiber dimension measurements indicate that the fiber length category ranges from fairly short to very long.

Fault diagnosis-based SDG transfer for zero-sample fault symptom

The traditional fault diagnosis models cannot achieve good fault diagnosis accuracy when a new unseen fault class appears in the test set, but there is no training sample of this fault in the training set. Therefore, studying the unseen cause-effect problem of fault symptoms is extremely challenging. As various faults often occur in a chemical plant, it is necessary to perform fault causal-effect diagnosis to find the root cause of the fault. However, only some fault causal-effect data are always available to construct a reliable causal-effect diagnosis model. Another worst thing is that measurement noise often contaminates the collected data. The above problems are very common in industrial operations. However, past-developed data-driven approaches rarely include causal-effect relationships between variables, particularly in the zero-shot of causal-effect relationships. This would cause incorrect inference of seen faults and make it impossible to predict unseen faults. This study effectively combines zero-shot learning, conditional variational autoencoders (CVAE), and the signed directed graph (SDG) to solve the above problems. Specifically, the learning approach that determines the cause-effect of all the faults using SDG with physics knowledge to obtain the fault description. SDG is used to determine the attributes of the seen and unseen faults. Instead of the seen fault label space, attributes can easily create an unseen fault space from a seen fault space. After having the corresponding attribute spaces of the failure cause, some failure causes are learned in advance by a CVAE model from the available fault data. The advantage of the CVAE is that process variables are mapped into the latent space for dimension reduction and measurement noise deduction; the latent data can more accurately represent the actual behavior of the process. Then, with the extended space spanned by unseen attributes, the migration capabilities can predict the unseen causes of failure and infer the causes of the unseen failures. Finally, the feasibility of the proposed method is verified by the data collected from chemical reaction processes.

Echocardiographic measurements of left ventricular dimensions and function in newborns with omphalocele and pulmonary

PurposeThe purpose of this study was to explore echocardiographic parameters of the left ventricle (LV) in relation to the outcomes of omphalocele neonates with pulmonary hypertension (PH).MethodsThis retrospective study was conducted among omphalocele patients with PH born from 2019 to 2020. Patients in this study did not have additional severe malformations or chromosomal aberrations. Patients who died under palliative care were excluded. The echocardiographic parameters of LV were obtained within 24 h after birth. Clinical and outcomes data were recorded, echocardiograms evaluated for left ventricular internal dimension in end-diastole (LVIDd), end-diastolic volume (EDV), stroke volume (SV) and cardiac output index (CI), among others.ResultsThere were 18 omphalocele newborns with PH, of whom 14 survived and 4 died. Both groups were comparable in the baseline characteristics. Non-survival was associated with a smaller LV [LVIDd (12.2 mm versus15.7 mm, p < 0.05), EDV (3.5 ml versus 6.8 ml, p < 0.05)] and with worse systolic function [SV (2.3 ml versus 4.2 ml, p < 0.05), and CI (1.7 L/min/m2 versus 2.9 L/min/m2, p < 0.01)].ConclusionIn the cohort of omphalocele patients with PH, lower LVIDd, EDV, SV and CI were associated with mortality.Level of evidenceLevel III.

Error analysis of precision measurement with monocular vision

To systematically study the measurement error of the calibration coefficient method when the camera’s optical axis is not perpendicular to the measurement plane, this paper first discusses the principle of error measurement with 2D imaging model, and then derives the distribution relationship of physical points corresponding to evenly distributed pixels in the pixel coordinate system based on the projection transformation matrix of the vision system. Theoretical analysis reveals an equivariance series in the expression of physical point intervals. Considering rotational symmetry of the coordinate axis, this paper analyzes the geometric relationship when the calibration plane rotates around the axis and derives the mathematical expression for dimensional measurement. Finally, an experimental platform with both industrial and telecentric lenses is proposed and designed. Experimental results demonstrate that the measurement results of the expression derived in this paper are consistent with the traditional coordinate transformation method and the maximum deviation of the measurement is less than 0.06 mm, validating the theoretical analysis presented in this paper and providing theoretical guidance for subsequent practical application.

A Sparse Sensor Placement Strategy Based on Information Entropy and Data Reconstruction for Ocean Monitoring

Sparse sensor placement strategies are applied to reconstruct a region’s full-state data conditioned to a limited number of sensors, particularly crucial to ocean monitoring systems. In maritime systems, existing sparse sensor placement methods consider the reconstruction error of data or rely on specific requirements. Considering how sensors acquire essential information for monitoring systems, the utilization of entropy from information theory becomes quite interesting. In this article, we show that entropy measurements on different quantities of information are sensitive to indicate the border areas, thus requiring a balance between the number of sensors needed and the amount of information collected by them in coastal areas. Due to such, we propose (i) a novel sparse sensor placement strategy based on entropy, where the entropy measurements in temporal dimension are utilized for sample selection, so portions of samples selected are utilized for training data, significantly improving the training efficiency without sacrificing accuracy of subsequent data reconstruction. In the proposed strategy, (ii) we use orthogonal triangle decomposition from linear algebra, where a low-cost sensor is employed as a pivot. In terms of spatial dimension, the entropy of each location is adopted as entropy weight to reconstruct full-state data. Additionally, (iii) the strategy employs a greedy algorithm of weighted column pivoting for the orthogonal triangle decomposition, which is designed to suit yet effectively seek additional information and minimal reconstruction error in each iteration processing step. Experimental results using Sea Surface Temperature (SST) data show that the proposed strategy outperforms existing methods, acquiring more information, ensuring higher efficiency, and reducing costs while minimizing reconstruction errors.

Radial cracks in Castanopsis hystrix wood and its dimensional stability improvement by resin-impregnated modification

Abstract This study investigated the characteristics of radial cracks in Castanopsis hystrix wood and evaluated its dimensional stability after impregnation with low-molecular-weight polyacrylate (PA), melamine-urea-glyoxal (MUG), and melamine-urea-formaldehyde (MUF) resins. The physical properties were examined by dimensional stability measurements, dynamic vapor sorption (DVS) analysis, and scanning electron microscopy (SEM). The results showed that radial cracks were easily produced in the transverse section of untreated wood during drying. The surfaces of the radial cracks exhibited an even and clean structure without fluffs on the pair of surfaces, and cracks spanned 4–5 annual rings. The resin-impregnated wood showed no radial cracks on its transverse surface. C. hystrix wood modified with MUG and MUF exhibited a higher weight percentage gain (WPG) than wood modified with the same concentration of PA resin. The resin-impregnated C. hystrix wood also showed reduced anisotropy and improved dimensional stability. The SEM images of the modified wood showed that the wood pits and cells were filled with resin, while the cell wall surfaces were covered with a layer of resin.

Long term impact of measured and predicted prosthesis patient mismatch following transcatheter aortic valve replacement

Abstract Objectives To investigate the long-term clinical impact of prosthesis-patient mismatch (PPM) in patients undergoing transcatheter aortic valve implantation(TAVI). Background Both measured and predicted effective orifice area indexed to the body surface area (EOAi) have been suggested to define PPM in patients undergoing TAVI. The impact of PPM on clinical outcomes may accumulate with extended follow-up and vary according to the definition used. Methods Patients included in a prospective TAVI registry were stratified by the presence of moderate (0.65-0.85 cm2/m2 or 0.55-0.70 cm2/m2 if obese) or severe (≤0.65 cm2/m2 or ≤0.55 cm2/m2 if obese) PPM according to echocardiographically measured EOAi (measured PPM) prior to discharge, predicted EOAi based on published EOA reference values for each valve model and size (predicted PPMTHV), or predicted EOAi based on EOA reference derived from computed tomography measurements of aortic annulus dimension (predicted PPMCT). Results In an analysis of 2,463 patients, the incidence of measured PPM (moderate: 27.0%; severe: 8.7%) was higher than the incidence of predicted PPMTHV (moderate: 11.3%; severe: 1.2%) or predicted PPMCT (moderate: 12.0%; severe: 0.1%). During a median time to death of 843 days, mortality rates at 10 years were comparable in patients with versus without measured PPM or predicted PPMCT. In contrast, patients with moderate predicted PPMTHV had a lower risk of 10-year all-cause mortality compared with those without PPM (HR: 0.69; 95% CI: 0.52-0.90). Conclusions The use of predicted as compared to measured EOAi results in a lower estimate of PPM severity in TAVI ptients. We observed no increased risk of death in patients with PPM throughout 10-year of follow-up.Incidence of PPM after TAVIImpact of Measured an Predicted PPM

Normative Measurements of L1 to S1 Neuroforaminal Dimensions Derived From Plain Film Radiography, Computed Tomography, and Magnetic Resonance Imaging.

Retrospective cohort. To report normative measurements of L1 to S1 lumbar neuroforamina on plain film radiography (PFR), computed tomography (CT), and magnetic resonance imaging (MRI), accounting for patients' sex and ethnicity. The quantitative criteria fothe diagnosis of neuroforaminal stenosis remains unknown. Acquiring a thorough understanding of normative foraminal dimensions is a key step in formulating objective parameters for neuroforaminal stenosis. We measured 988 images from 494 patients between 18 and 35 years old without spinal pathology who received PFR, CT, or MRI within 1 year of each other. Neuroforaminal measurements were defined as the height, area, and sagittal and axial widths. Statistical analyses were performed to assess relationships among PFR, CT, and MRI-derived neuroforaminal measurements, as well as the influence of patients' sex and ethnicity. 330 PFR, 377 CT, and 281 MRI were measured. Of these, 213 PFR and CT, 117 PFR and MRI, and 164 MRI and CT intrapatient images were compared. Statistically significant differences were observed among PFR, CT, and MRI measurements across all levels L1 to S1. PFR measurements were larger compared with those derived from CT and MRI. Weak-to-moderate correlations were observed between PFR and CT, PFR and MRI, and CT and MRI, with the magnitude of correlation decreasing caudally from L1 to S1. Variations in neuroforaminal anatomy were observed based on sex and ethnicity. This study reports 25,951 measurements of normal L1 to S1 neuroforaminal anatomy assessed by PFR, CT, and MRI. The values reported in this study may be used as normative reference measurements of the lumbar neuroforamina. PFR measurements of the neuroforamina are larger compared with those derived from CT and MRI across all levels from L1 to S1. There is a poor correlation between PFR, CT, and MRI when measuring the lumbar neuroforamina. Differences in neuroforaminal anatomy are evident based on patients' sex and ethnicity.

Comparison of cone-beam and fan-beam computed tomography and low-field magnetic resonance imaging for detection of palmar/plantar osteochondral disease in Thoroughbred horses.

Palmar/plantar osteochondral disease (POD) of the metacarpal/tarsal condyles is a common pathological finding in racehorses. To compare diagnoses, imaging details, and measurements of POD lesions between cone-beam computed tomography CT (CBCT), fan-beam CT (FBCT), and low-field magnetic resonance imaging (MRI) using macroscopic pathology as a gold standard. Cross-sectional study. Thirty-five cadaver limbs from 10 horses underwent CBCT, FBCT, MRI, and macroscopic examination. CT and MR images were examined for presence of POD, imaging details of POD, and measurements of POD dimensions and areas. Imaging diagnoses, details, and measurements were compared with macroscopic examination and between modalities. Forty-eight POD lesions were seen over 70 condyles. Compared with macroscopic examination the sensitivity and specificity of diagnosis were 95.8% (CI95 = 88%-99%) and 63.6% (CI95 = 43%-81%) for FBCT, 85.4% (CI95 = 74%-94%) and 81.8% (CI95 = 63%-94%) for CBCT, and 69.0% (CI95 = 54%-82%) and 71.4% (CI95 = 46%-90%) for MRI. Inter-modality agreement on diagnosis was moderate between CBCT and FBCT (κ = 0.56, p < 0.001). POD was identified on CT as hypoattenuating lesions with surrounding hyperattenuation and on MRI as either T1W, T2*W, T2W, and STIR hyperintense lesions or T1W and T2*W heterogeneous hypointense lesions with surrounding hypointensity. Agreement on imaging details between CBCT and FBCT was substantial for subchondral irregularity (κ = 0.61, p < 0.001). Macroscopic POD width strongly correlated with MRI (r = 0.81, p < 0.001) and CBCT (r = 0.79, p < 0.001) and moderately correlated with FBCT (r = 0.69, p < 0.001). Macroscopic POD width was greater than all imaging modality (p < 0.001). Effect of motion artefact in live horse imaging could not be assessed. All imaging modalities were able to detect POD lesions, but underestimated lesion size. The CT systems were more sensitive, but the differing patterns of signal intensity may suggest that MRI can detect changes associated with POD pathological status or severity. The image features observed by CBCT and FBCT were similar.

Comparison of L1-S1 neuroforaminal dimensions derived from plain film radiography versus computed tomography.

To compare measurements of lumbar neuroforaminal dimensions (NFD) derived from plain film radiography (PFR) and computed tomography (CT) of young patients without spinal pathology. We analyzed 213 patients between 18 and 35years of age without spinal pathology who received PFR and CT within one year of each other. NFD were defined as foraminal height, sagittal anterior-to-posterior width, and area. Statistical analyses assessed correlations and differences between PFR- and CT-derived NFD measurements. 111 subjects were female and 102 were male. Significant differences between PFR- and CT-derived NFD measurements were observed for all levels L1-S1, with those for foraminal height listed as follows: 4.10mm at L1-L2, 1.58mm at L2-L3, 3.23mm at L3-L4, 4.27mm at L4-L5, and 1.75mm at L5-S1. Regarding foraminal area, these differences were 72.20, 73.45, 61.80, 35.38, and 16.18 mm2, respectively. PFR-derived measurements of NFD were larger compared to those derived from CT across all levels (p < .001). Only weak (0 ≤ r ≤ .4) or moderate (.4 ≤ r ≤ .7) correlations were observed between PFR- and CT-derived NFD measurements for all levels from L1-S1. This study describes 9585 measurements from L1-S1 of neuroforaminal measurements derived from CT and plain film radiography from a sample of young patients without spinal pathology. Among these patients, plain film measurements of the neuroforamina are larger compared to those derived from CT for all levels from L1-S1. There is poor correlation and reliability between plain film and CT measurements of neuroforaminal dimensions.

Two different experimental approaches for the uncertainty determination of X-ray computed tomography dimensional measurements on lattice structures

X-ray computed tomography (CT) is increasingly used in industrial dimensional metrology. However, the establishment of metrological traceability can be challenging for CT dimensional measurements, as the evaluation of their uncertainty is generally non-trivial. Moreover, uncertainty determination becomes even more difficult when dealing with complex measurement tasks, such as in the case of lattice structures produced by additive manufacturing, characterized by features not accessible from the outside and/or by complex surface topographies, which are problematic to be calibrated using other measuring principles to ensure sufficiently low calibration uncertainty. This paper presents a critical investigation of two different experimental approaches for the uncertainty determination of CT dimensional measurements performed on components with inaccessible and/or complex geometries, as well as complex surface topography. The first approach, the “substitution method”, is applied in this work using a newly developed reference object as the basis for the uncertainty assessment procedure through substitution measurements. The second one, the “multiple measurements approach”, is based on repeated measurements both on the uncalibrated workpiece in multiple orientations and on simple calibrated standards. This second approach, initially introduced some years ago for tactile coordinate measuring machines, is now investigated in this work for its application to CT metrology. The two approaches are discussed and compared through an industrial case study: the dimensional verification of lattice structures fabricated by metal additive manufacturing. For the selected case, both approaches yielded comparable measurement results and uncertainties. Finally, the multiple measurements approach was further investigated by applying it to the CT measurement of the calibrated object. The paper also discusses the open issues of both methods and outlines directions for future investigations.

Long-term outcomes of measured and predicted prosthesis-patient mismatch following transcatheter aortic valve replacement.

Both measured and predicted effective orifice area (EOA) indexed to the body surface area (EOAi) have been suggested to define prosthesis-patient mismatch (PPM) in patients undergoing transcatheter aortic valve replacement (TAVR). The impact of PPM on clinical outcomes may accumulate with extended follow-up and vary according to the definition used. We aimed to investigate the long-term clinical impact of PPM in patients undergoing TAVR. Patients in a prospective TAVR registry were stratified by the presence of moderate (0.65-0.85 or 0.55-0.70 cm2/m2 if obese) or severe (≤0.65 or ≤0.55 cm2/m2 if obese) PPM according to echocardiographically measured EOAi (measured PPM), predicted EOAi based on published EOA reference values for each valve model and size (predicted PPMTHV), or predicted EOAi based on EOA reference values derived from computed tomography measurements of aortic annulus dimensions (predicted PPMCT). In an analysis of 2,463 patients, the frequency of measured PPM (moderate: 27.0%; severe: 8.7%) was higher than the frequency of predicted PPMTHV (moderate: 11.3%; severe: 1.2%) or predicted PPMCT (moderate: 12.0%; severe: 0.1%). During a median follow-up of 429 days, 10-year mortality was comparable in patients with versus without measured PPM or predicted PPMCT. In contrast, patients with moderate predicted PPMTHV had a lower risk of 10-year all-cause mortality compared with those without PPM (adjusted hazard ratio: 0.73, 95% confidence interval: 0.55-0.96). The use of predicted versus measured EOAi results in a lower estimate of PPM severity. We observed no increased risk of death in patients with PPM over a median follow-up time of 429 days. gov: NCT01368250.

Comparison of intracardiac vs. transesophageal echocardiography for "one-stop" procedures of combined radiofrequency catheter ablation and left atrial appendage closure with the Watchman device in the treatment of atrial fibrillation.

This study aimed to assess the efficacy and safety of "one-stop" procedures that combined radiofrequency catheter ablation and left atrial appendage closure (LAAC) with the Watchman device under the guidance of intracardiac echocardiography (ICE) vs. transesophageal echocardiography (TEE) in patients with atrial fibrillation. In this study, we prospectively enrolled patients who underwent "one-stop" procedures under the guidance of ICE (n = 193, 109 men, 65.02 ± 8.47 years) or TEE (n = 109, 69 men, 64.23 ± 7.75 years) between January 2021 and October 2022. Intraprocedural thrombus formation in the left atrial appendage (LAA) was observed in 3 (1.46%) patients in the ICE group and 15 (11.63%) patients in the TEE group (P < 0.05) before LAAC. Total fluoroscopy time and dose in the ICE group were less than those in the TEE group. The total "one-stop" turnaround time and LAAC procedure time in the ICE group were significantly shorter than those in the TEE group (P < 0.05). Postoperative esophagus discomfort, nausea and vomiting, and hypotension were more often seen in the TEE group (P < 0.001). There was no significant difference in matched cases between ICE and fluoroscopy measurements (P = 0.082). The TEE results related to LAAC and clinical events were similar between the two groups during the follow-up (P > 0.05). The ICE-guided "one-stop" procedure was safe and feasible with less radiation exposure, shorter turnaround time, and fewer complications and intraoperative thrombus formations than the TEE group. ICE offered accurate measurements in the LAA dimension during LAAC. Echocardiography during the "one-stop" procedures was necessary to rule out the intraoperative thrombus.

Comparative evaluation of methods fordetermining the width of the upper jaw in growing patients

Aim. To conduct a comparative evaluation of methods for measuring the width of the upper jaw in growing patients in order to determine the difference between these standard values and improve diagnostics. Materials and methods. The study was conducted in 20 patients aged 6, 8, 10 and 12 years. Measurement of the transversal dimensions of the jaws was carried out on frontal cephalograms using the Ricketts cephalometric analysis, and on CBCT scans using the analysis of the University of Pennsylvania. Results. The results of measurements by frontal cephalograms and CBCT scans have almost the same indicators, the data of both methods differ insignificantly. Conclusions. As a result of the study, both methods confirmed their reliability, however, the analysis of cone-beam computed tomography has a number of advantages. Accordingly, it is possible to simplify the carrying out of diagnostic measures to determine the width of the upper jaw, limiting ourselves to one research method – cone-beam computed tomography without prescribing additional teleroentgenography.

Helicon waves in a converging-diverging magnetoplasma

Waves propagating along a converging-diverging rf magnetoplasma having the characteristics of a bounded m = 0 helicon mode are reported and characterised. The discharge features a 30cm separation between the region of radiofrequency energy deposition by a single loop antenna and the region of maximum magnetic field applied by a pair of coils. With 200W of rf input power, up to a five-fold increase in axial plasma density between the antenna and the magnetic mirror throat is observed together with an Ar II blue-mode. Two dimensional B-dot probe measurements show that the rf magnetic fields are closely guided by the converging-diverging geometry. The wave is characterised as a m = 0 mode satisfying the helicon dispersion relation on-axis with radial boundary conditions approximately matching the radii of the plasma column. Analysis of the wave phase velocity and wave axial damping failed to identify collisionless or collisional wave-plasma coupling mechanisms. Instead, the wave axial amplitude variations can be explained by local wave resonances and possible reflections from localised rapid changes of the refractive index. A Venturi-like effect owing to the funnel-shaped magnetoplasma and conservation of the wave energy may also explain some level of amplitude variations.

Artificial Intelligence for Improved Hepatosplenomegaly Diagnosis.

Hepatosplenomegaly is commonly diagnosed by radiologists based on single dimension measurements and heuristic cut-offs. Volumetric measurements may be more accurate for diagnosing organ enlargement. Artificial intelligence techniques may be able to automatically calculate liver and spleen volume and facilitate more accurate diagnosis. After IRB approval, 2 convolutional neural networks (CNN) were developed to automatically segment the liver and spleen on a training dataset comprised of 500 single-phase, contrast-enhanced CT abdomen and pelvis examinations. A separate dataset of ten thousand sequential examinations at a single institution was segmented with these CNNs. Performance was evaluated on a 1% subset and compared with manual segmentations using Sorensen-Dice coefficients and Pearson correlation coefficients. Radiologist reports were reviewed for diagnosis of hepatomegaly and splenomegaly and compared with calculated volumes. Abnormal enlargement was defined as greater than 2 standard deviations above the mean. Median Dice coefficients for liver and spleen segmentation were 0.988 and 0.981, respectively. Pearson correlation coefficients of CNN-derived estimates of organ volume against the gold-standard manual annotation were 0.999 for the liver and spleen (P < 0.001). Average liver volume was 1556.8 ± 498.7 cc and average spleen volume was 194.6 ± 123.0 cc. There were significant differences in average liver and spleen volumes between male and female patients. Thus, the volume thresholds for ground-truth determination of hepatomegaly and splenomegaly were determined separately for each sex. Radiologist classification of hepatomegaly was 65% sensitive, 91% specific, with a positive predictive value (PPV) of 23% and an negative predictive value (NPV) of 98%. Radiologist classification of splenomegaly was 68% sensitive, 97% specific, with a positive predictive value (PPV) of 50% and a negative predictive value (NPV) of 99%. Convolutional neural networks can accurately segment the liver and spleen and may be helpful to improve radiologist accuracy in the diagnosis of hepatomegaly and splenomegaly.

Is There a Relationship Between Unilateral/Bilateral Impacted Maxillary Canines and Nasal Septum Deviation?

Introduction A deviated nasal septum may be associated with some dentofacial deformities. The aim of the study was to determine whether there is a relationship between some craniomaxillary features of unilateral and bilateral maxillary impacted canines and nasal septum deviation. Methods This is a retrospective study consisting of cone beam computed tomography (CBCT) images of 51 patients. All patients were divided into three subgroups: unilateral maxillary impacted canines (UMIC) (n=19) bilateral maxillary impacted canines (BMIC) (n=15), and control group (MC) (n=17). The septal deviation angle and some angular and dimensional measurements were performed. Differences in linear and angular measurements between the groups were analyzed using One-way ANOVA and the Kruskal-Wallis test. Pearson's correlation analysis was performed to determine the relationship between the septal deviation angle, septal deviation direction, nasal floor angle, and other parameters, and multivariate linear regression analysis was performed to determine the effect of variables in the septal deviation angle. Results Bilateral or unilateral position of the impacted canines was found to be effective on septal deviation. The septal deviation angle and the nasal floor angle values were found to be significantly higher in the UMIC and BMIC groups (p<0.001) than in the MC group. Maxillary width was found to be significantly lower in the BMIC group compared to the UMIC (p<0.01) and MC group (p<0.001). Septal deviation angle was positively correlated with septal deviation direction and nasal floor angle (p<0.001). Palatal width and nasal floor angle were found to be negatively correlated (p<0.05), and palatal depth and septal deviation direction were found to be positively correlated (p<0.01). Groups and septal deviation angle, septal deviation direction, and nasal floor angle were found to be negatively correlated (p<0.001). The multivariate linear regression analysis revealed an association between septal deviation angle, group (p<0.01), and nasal floor angle (p<0.05). Conclusion Bilateral or unilateral position of the impacted canines was found to be effective on septal deviation.The septal deviation angle values were found to be higher when the maxillary impacted canine was unilateral. Unilateral or bilateral positions of the impacted canine and the nasal floor angle were found to be factors affecting the formation of septal deviation.

Assessment of correlation between hand-wrist maturation and cervical vertebral maturation: a fractal analysis study

BackgroundTo investigate whether fractal dimension (FD) measurements from hand-wrist radiographs and lateral cephalometric radiographs are correlated with each other and with skeletal maturation stages.MethodsIn this retrospective study conducted on hand-wrist and lateral cephalometric radiographs obtained from patients between 2017 and 2023, hand-wrist maturation stages (HWMS) and cervical vertebral maturation stages (CVMS) of 144 subjects (6 to 17 years of age) were assessed radiographically. The participants were divided into nine groups (n = 16 each) based on HWMS. Fractal analysis was performed on the radiographs of the radius, the middle finger phalanges (proximal, medial and distal), and the cervical vertebral bodies (C2, C3, C4). Mean and standard deviation values, Spearman’s and Pearson correlation analyses, one-way ANOVA, Kruskal-Wallis H tests and Mann-Whitney-U test were used to evaluate the data.ResultsPositive correlations were found between the FD values of the radius and HWMS or CVMS (r = .559, P = .001, r = .528 P = .001 respectively). The FD values of the radius were positively correlated with those of all cervical vertebrae (C2, C3, C4), proximal and medial phalanges as well as age. FD values measured from the proximal phalanx, medial phalanx and radius showed significant differences among both HWMS and CVMS (P < .05). HWMS was strongly correlated with CVMS (r = .929, P = .001). Age was strongly correlated with HWMS (r = .795, P = .001) and CVMS (r = .756, P = .001). There was a significant difference in terms of age distribution among HWMS and CVMS (P < .05).ConclusionsFD measurements on hand-wrist radiographs can provide useful information for the assessment of skeletal maturation stage. Especially, FD measurements from the radius are important and more reliable to predict skeletal maturation stage.

Dynamical fractal: Theory and case study

Urbanization is a phenomenon of concern for planning and public health: projections are difficult because of policy changes and natural events, and indicators are multiple. There are previous studies of development that used fractals, but none for this specific problem, nor extrapolating the future trend. In the first part of this paper, we construct a theoretical framework for analyzing dynamic (changing) fractals and extrapolating their future trends based on their fractal dimension—a measure of the complexity of the fractal. We believe this approach holds enormous potential for applications in analyzing changing fractals in the real world, such as urban growth, cells, cancers, etc., all of which are invaluable to research. This theoretical framework may shed light on a factor overlooked in past research: the trend of how fractals change. In the second part of this paper, we apply this theoretical framework to study the urbanization of Boston. We compare several maps and measurements of fractal dimensions, produce code11https://github.com/yinj66/fractal-dimension. that reads the maps and divides the city into subsections, and ultimately graph the fractal dimension over time using both differential and difference equations. Finally, we postulate the logistic equation as a model to fit the evolution of the fractal dimension, as well as the total population derived from census data, which serves as a component for comparing dynamical fractals.

Associations of burnout with job demands/resources during the pandemic in health workers from Southeast European countries.

Despite several studies assessing job demands and burnout in countries from the Southeast European (SEE) region, there is still a lack of data about the psychological impact of the pandemic on health workers (HWs). The present study aimed to demonstrate and compare levels of burnout dimensions in HWs from SEE countries and to reveal the burnout-job demands/resources relationships in these workers during the pandemic. During the autumn of 2020, this online multicentric cross-sectional survey studied a large group (N = 4.621) of HWs working in SEE countries. The Maslach Burnout Inventory was used for the measurement of burnout dimensions. We analyzed the job demands by using the Hospital Experience Scale. Remuneration and relationships with superiors were measured using the Questionnaire sur les Ressources et Contraintes Professionnelles (English version). A series of ANOVA comparisons of means revealed the countries in which respondents showed higher mean values of emotional exhaustion (Bosnia and Herzegovina, Bulgaria, Croatia, Moldova, Montenegro, and North Macedonia) and the countries in which respondents showed lower mean values of this burnout dimension (Israel and Romania) (Welch F = 17.98, p < 0.001). We also found differences among HWs from different countries in job demands and job resources. The testing of hierarchical regression models, which have been controlled for certain confounding factors, clearly revealed that emotional exhaustion was predicted by job demands (R2 = 0.37) and job resources (R2 = 0.16). Preventive measures for the improvement of mental health in HWs during the pandemic and beyond have to take into account the differences between countries regarding the country context and current scientific knowledge. A modified stress test should be implemented in hospitals regarding future shocks that might include new pandemics, terrorism, catastrophes, or border conflicts.