Objective To investigate the radiological features of degenerative cervical kyphosis (DCK) and the relationship between cervical sagittal parameters. Methods The quality of life scores and imaging data of 89 patients with DCK treated between February 2019 and February 2022 were retrospectively analysed. There were 47 males and 42 females, with an average age of 48.4 years (range, 25-81 years). Quality of life scores included visual analogue scale (VAS) score and neck disability index (NDI). The imaging data included C0-C2 angle, C2-C7 angle, C3-C7 inclination of zygapophyseal joints, C7 slope (C7S), cervical sagittal vertical axis (cSVA), kyphosis range, and kyphosis focal. The patients were grouped by gender, and the differences of the above parameters between the two groups were compared. Pearson correlation was used to analyze the relationship between age, quality of life scores, and cervical sagittal parameters, and the relationship between cervical sagittal parameters. Results The preoperative VAS score was 0-9 (mean, 4.3); NDI was 16%-44% (mean, 30.0%). There was no significant difference in VAS score and NDI between male and female groups (P>0.05). The kyphosis range of cervical spines was C3-5 in 3 cases, C3-6 in 41 cases, C3-7 in 30 cases, C4-6 in 4 cases, C4-7 in 10 cases, C5-7 in 1 case, and the kyphosis focal was mostly located between C4-C5 (78/89, 87.64%). The C3-C7 inclination of zygapophyseal joints were (60.25±5.56)°, (55.42±5.77)°, (53.03±6.33)°, (58.39±7.27)°, and (64.70±6.40)°, respectively. The C0-C2 angle, C2-C7 angle, C7S, and cSVA were (–23.81±6.74)°, (10.15±2.94)°, (15.31±4.59)°, and (2.37±1.19) mm, respectively. The C7S and cSVA of males were significantly larger than females (P<0.05), with no significant difference in other parameters between male and female groups (P>0.05). VAS score and NDI were negatively correlated with C0-C2 angle (P<0.05), and positively correlated with C2-C7 angle and cSVA (P<0.05); VAS score was negatively correlated with C7S (P<0.05). Except VAS, NDI and all cervical sagittal parameters were affected by age. Age was positively correlated with NDI, C7S, and cSVA (P<0.05), and negatively correlated with C0-C2 angle and C2-C7 angle (P<0.05). The correlation analysis of cervical sagittal parameters showed that C0-C2 angle was negatively correlated with C2-C7 angle and cSVA (P<0.05); C7S was negatively correlated with C2-C7 angle (P<0.05) and positively correlated with cSVA (P<0.05). There was no correlation among other parameters (P>0.05). ConclusionThe inclination of zygapophyseal joints of cervical spines of DCK patients is U-shaped in the kyphosis range, and the inclination at the kyphosis focal is the smallest. When cervical degenerative kyphosis occurs, in addition to the interaction of sagittal parameters, age, gender, neck pain, and dysfunction will also affect the cervical sagittal balance. Furthermore, cervical curvature and morphological changes are not purely local problems.
ObjectiveTo analyze the the characteristics of pulse oximetry (SpO2) curve changes in patients with obstructive sleep apnea (OSA), hypoxic parameters and to explore the difference and connection between obstructive apnea (OA) events and hypopnea (Hyp) events, evaluate the impact of different types of obstructive respiratory events on hypoxia, and provide a theoretical basis for exploration of hypoxic differences in each type of respiratory events and construction of prediction models for respiratory event types in the future. MethodsSixty patients with OSA diagnosed by polysomnography (PSG) were selected for retrospective analysis, and all respiratory events with oxygen drop in the recorded data overnight were divided into OA group (5972) according to the type of events and Hyp group (4110), recorded and scored events were exported from the PSG software as comma-separated variable (.csv) files, which were then imported and analyzed using the in-house built Matlab software. Propensity score matching was performed on the duration of respiratory events and whether they were accompanied by arousal in the two groups, and minimum oxygen saturation of events (e-minSpO2), the depth of desaturation (ΔSpO2), the duration of desaturation and resaturation (DSpO2), the duration of desaturation (d.DSpO2), duration of resaturation (r.DSpO2), duration of SpO2<90% (T90), duration of SpO2<90% during desaturation (d.T90), duration of SpO2<90% during resaturation (r.T90), area under the curve of SpO2<90% (ST90), area under the curve of SpO2<90% during desaturation (d.ST90), area under the curve of SpO2<90% during resaturation (r.ST90), oxygen desaturation rate (ODR) and oxygen resaturation rate (ORR), a total of 13 hypoxic parameters differences. ResultsVarious hypoxic parameters showed that more severe SpO2 desaturation in severe OSA patients, compared with mild and moderate OSA patients (P<0.05); There were statistically significant differences in the respiratory events duration and whether accompanied by arousal between the Hyp group and OA group (P<0.05), and the respiratory events duration and whether accompanied by arousal were significantly correlated with most hypoxic parameters; After accounting for respiratory events duration and whether accompanied by arousal by propensity score matching, compared with the Hyp group, e-minSpO2 was significantly lower in the OA group, ΔSpO2, d.DSpO2, r.DSpO2, ODR, ORR, T90, d.T90, r.T90, ST90, d.ST90, r.ST90 were significantly increased (P<0.05). ConclusionsDue to pathophysiological differences, all hypoxic parameters suggest that OA events will result in a more severe desaturation than Hyp events. Clinical assessment of OSA severity should not equate OA with Hyp events, which may cause more damage to the organism, establishing a basis for applying nocturnal SpO2 to automatically identify the type of respiratory event.
ObjectiveTo find out the diagnostic power and correlation between platelet-related parameters and inflammatory indicators in acute pancreatitis patients with different severity.MethodsA total of 88 patients with acute pancreatitis diagnosed in West China Hospital of Sichuan University from January 2019 to August 2019 were enrolled in the retrospective study, including 58 mild acute pancreatitis patients and 30 severe acute pancreatitis patients. The patients’ platelet-related parameters and inflammatory indicators were collected. The platelet parameters and inflammatory indicators in different severity acute pancreatitis groups were compared and the diagnostic power and correlation were analyzed.ResultsThe platelet count and plateletcrit of the severe group were lower than those of the mild group, the difference was statistically significant (Z=–5.502, –3.673; P<0.001). The immature platelet fraction, platelet distribution width, mean platelet volume and platelet-large cell ratio levels of the severe group were higher than those of the mild group (Z=–4.217, –2.998, –3.754, –3.816; P<0.05). Platelet-related parameters platelet count, immature platelet fraction, platelet distribution width, mean platelet volume, platelet-large cell ratio, plateletcrit and inflammatory indicators procalcitonin, interleukin-6 showed good diagnostic power with areas under under receiver operating characteristic curves greater than 0.75 in differentiating the severity of acute pancreatitis. Correlation analysis showed that immature platelet fraction was positively correlated with procalcitonin and interleukin-6 levels in patients with acute pancreatitis (rs=0.457, 0.385; P<0.05).ConclusionsImmature platelet fraction is correlated with the severity of acute pancreatitis, and positively correlated with the levels of inflammatory indicators procalcitonin and interleukin-6.
In order to study the variation of complex impedance and characteristic parameters on human normal and tumor lung tissue during the extracorporeal time, we established a real part-imaginary part chart of complex impedance on lung tissue which provided the basic theory and the reference data for research on elementary medicine and clinical diagnosis of lung cancer and meanwhile provided prior information for electrical impedance tomography (EIT) research. In the experiment carried out in our laboratory, when operation was finished, we kept the lung cancer tissue and normal tissue neatly separated into the cylindrical testing cavities and kept the temperature and humidity at expected values. Then the measurements of complex impedance property are performed at frequency from 1 000 Hz to 30 MHz using 4294A impedance analyzer of Aglient Company. With time changing, the results showed that there was a significant change occurring on the complex impedance of human normal and tumor lung tissue. However, the impedance of normal lung tissue is greater than that of tumor lung tissue. We consider that this change should be related to the change in extracellular fluid, intracellular fluid and cell membrane.
This study was aimed to estimate the effect of different ProDisc-C arthroplasty designs after it was implanted to C5-C6 cervicalspine. Finite element (FE) model of intact C5-C6 segments including the vertebrae and disc was developed and validated. Ball-and-socket artificial disc prosthesis model (ProDisc-C, Synthes) was implanted into the validated FE model and the curvature of the ProDisc-C prosthesis was varied. All models were loaded with compressed force 74 N and the pure moment of 1.8 Nm along flexion-extension and bilateral bending and axial torsion separately. The results indicated that the variation in the curvature of ball and socket configuration would influence the range of motion in flexion/extension, while there were not apparently differences under other conditions of loads. The method increasing the curvature will solve the stress concentration of the polyethylene, but it will also bring adverse outcomes, such as facet joint force increasing and ligament tension increasing. Therefore, the design of artificial discs should be considered comprehensively to reserve the range of motion as well as to avoid the adverse problems, so as not to affect the long-term clinical results.
The link between micro- and macro-parameters for radiation interactions that take place in living biological systems is described in this paper. Meanwhile recent progress and development in microdosimetry and nanodosimetry are introduced, including the methods to measure and calculate these micro- or nano-parameters. The relationship between radiobiology and physical quantities in microdosimetry and nanodosimetry was presented. Both the current problems on their applications in radiation protection and radiotherapy and the future development direction are proposed.
A fitting method of calculating local helix parameters of proteins based on dual quaternions registration fitting (DQRFit) is proposed in this paper. First, the C and N atom coordinates of each residue in the protein structure data are extracted. Then the unregistered data and reference data are constructed using the sliding windows. The square sum of the distance of the data points before and after registration is regarded as an optimization goal. We calculate the optimal rotation matrix and the translation vector using the dual quaternion registration algorithm, and get the helix parameters of the secondary structure which contain the number of residues per turn(τ), helix radius(ρ)and helix pitch(p). Furthermore, we can achieve the fitting of three-helix parameters of τ, ρ, p simultaneously with the dual quaternion registration, and can adjust the sliding windows to adapt to different error levels. Compared with the traditional helix fitting method, DQRFit has some advantages such as low computational complexity, strong anti-interference, and high fitting accuracy. It is proven that the precision of proposed DQRFit for α helix detection is comparable to that of the dictionary of secondary structure of proteins (DSSP), and is better than that of other traditional methods. This is of great significance for the protein structure classification and functional prediction, drug design, protein structure visualization and other fields in the future.
Objective To investigate the changes of low back pain (LBP) and spinal sagittal parameters in patients with unilateral Crowe type Ⅳ developmental dysplasia of the hip (DDH) after total hip arthroplasty (THA). Methods The clinical data of 30 patients who met the selection criteria between October 2018 and March 2020 were retrospectively analyzed. Patients were divided into LBP group (16 cases) and control group (14 cases) according to whether there was LBP before operation. There was no significant difference between the two groups of patients in gender, age, body mass index, affected sides, preoperative Harris score (P>0.05). Full-length lateral X-ray films of the spine were taken within 1 week before operation and at 1 year after operation, and the following imaging indicators were measured: sacral slope (SS), lumbar lordosis (LL ), spinal tilt (ST), spine-sacral angle (SSA), sagittal vertebral axis (SVA). The visual analogue scale (VAS) score, lumbar Oswestry disability index (ODI), the Harris score of the hip joint before operation and at 1 year after operation, and the occurrence of postoperative complications were collected and analysed. Results In the LBP group, LBP was relieved to varying degrees at 1 year after operation, of which 13 patients (81.3%) had complete LBP remission; VAS score decreased from 4.9±2.3 preoperatively to 0.3±0.8, ODI decreased from 33.5±22.6 preoperatively to 1.3±2.9, the differences were all significant (t=7.372, P=0.000; t=5.499, P=0.000). There was no new chronic LBP in the control group during follow-up. The Harris scores of the two groups significantly improved when compared with those before operation (P<0.05); there was no significant difference between the two groups at 1 year after operation (t=0.421, P=0.677). There was no significant difference in imaging indexes between the two groups before operation and the difference between pre- and post-operation (P>0.05). At 1 year after operation, ST and SVA in the LBP group, SSA in the control group, and SS in the two groups significantly improved when compared with those before operation (P<0.05); there was no significant difference in the other indexes between the two groups before and after operation (P>0.05). Conclusion Unilateral Crowe type Ⅳ DDH patients with LBP before operation were all relieved of LBP after THA. The relief of LBP may be related to the improvement of spinal balance, but not to lumbar lordosis and its changes.
Currently, monitoring system of awareness of the depth of anesthesia has been more and more widely used in clinical practices. The intelligent evaluation algorithm is the key technology of this type of equipment. On the basis of studies about changes of electroencephalography (EEG) features during anesthesia, a discussion about how to select reasonable EEG parameters and classification algorithm to monitor the depth of anesthesia has taken place. A scheme which combines time domain analysis, frequency domain analysis and the variability of EEG and decision tree as classifier and least squares to compute Depth of anesthesia Index (DOAI) is proposed in this paper. Using the EEG of 40 patients who underwent general anesthesia with propofol, and the classification and the score of the EEG annotated by anesthesiologist, we verified this scheme with experiments. Classification and scoring was based on a combination of modified observer assessment of alertness/sedation (MOAA/S), and the changes of EEG parameters of patients during anesthesia. Then we used the BIS index to testify the validation of the DOAI. Results showed that Pearson's correlation coefficient between the DOAI and the BIS over the test set was 0.89. It is demonstrated that the method is feasible and has good accuracy.
The impeller, as a key component of artificial heart pumps, experiences high shear stress due to its rapid rotation, which may lead to hemolysis. To enhance the hemolytic performance of artificial heart pumps and identify the optimal combination of blade parameters, an optimization design for existing pump blades is conducted. The number of blades, outlet angle, and blade thickness were selected as design variables, with the maximum shear stress within the pump serving as the optimization objective. A back propagation (BP) neural network prediction model was established using existing simulation data, and a grey wolf optimization algorithm was employed to optimize the blade parameters. The results indicated that the optimized blade parameters consisted of 7 impeller blades, an outlet angle of 25 °, and a blade thickness of 1.2 mm; this configuration achieved a maximum shear stress value of 377 Pa—representing a reduction of 16% compared to the original model. Simulation analysis revealed that in comparison to the original model, regions with high shear stress at locations such as the outer edge, root, and base significantly decreased following optimization efforts, thus leading to marked improvements in hemolytic performance. The coupling algorithm employed in this study has significantly reduced the workload associated with modeling and simulation, while also enhancing the performance of optimization objectives. Compared to traditional optimization algorithms, it demonstrates distinct advantages, thereby providing a novel approach for investigating parameter optimization issues related to centrifugal artificial heart pumps.