Objective To compare the effect of two different methods of cell seeding on spatial distribution and gene expression of hBMSCs in biocoral scaffold in vitro cultures. Methods The composite of hBMSCs and biocoral scaffold was prepared by traditional seeding (group A) and fibrin glue seeding (group B). The seeding efficiency was measured after 30 minutes of incubation in group B and after 3 hours in group A. At 2, 7, 14 and 21 days after culture, the samples were harvestedand the serial longitudinal sections were cut for each embedded composite. The sections were stained with DAPI and were measured using fluorescence microscope with apotome under serial optical sections. The cell number in every 10 × objective field was automatically measured by AxioVision image analysis software and levels (from seeding surface to bottom L1-L5) or columns (from centre to margin) for comparing cell distribution were set up. The specific osteogenic genes [osteonectin (ON), core binding factor α1 (Cbfα1), osteocalcin (OC)] expression was measured by RT-PCR. Results The seeding efficiency was significantly higher in group B (88.32% ± 4.2%) than in group A (66.51% ± 12.33%, P lt; 0.01). At 2 days after culture, the cell number from L1 to L4 decreased gradully in two groups (P lt; 0.05); in the cell number of different columns, there was no significant difference in group A (Pgt; 0.05) whereas significant difference in group B (P lt; 0.05); there was no significant difference in gene expression between two groups (P gt; 0.05). At 7 days after culture, the cell number was less than that at 2 days in group A and there was significant difference among levels (P lt; 0.05). The cell number and osteogenic gene expression increased sharply and there appeared uniform cell distribution in group B (P gt; 0.05). The gene expression of ON and Cbfα1 in group B was higher than that in group A (Plt; 0.05). At 14 days after culture, the cell number in levels or columns in group A decreased sharply and was less than that at 7 days (P lt; 0.05); whereas the cell number was similar to that at 7 days in group B (P gt; 0.05). The OC gene expression reached the highest level in group B at 14 days. The gene expression was higher in group B than in group A (P lt; 0.05). At 21 days after culture, there was significant difference in the cell number among levels and in the gene expression between group A and group B (P lt; 0.05); there was no significant difference in the cell number among columns in two groups (Pgt; 0.05). In addition, the cell number of most levels and columns in group B was more than that in group A at 7, 14 and 21 days after culture (P lt; 0.05). Conclusion More uniform cell distribution with rapid prol iferation and osteogenic differentiation is available in different levels or columns of scaffold by fibrin glue seeding than by traditional seeding.
In the present work, Monte Carlo simulations were employed to study the characteristics of the dose distribution of high energy electron beam in the presence of uniform transverse magnetic field. The simulations carried out the transport processes of the 30 MeV electron beam in the homogeneous water phantom with different magnetic field. It was found that the dose distribution of the 30 MeV electron beam had changed significantly because of the magnetic field. The result showed that the range of the electron beam was decreased obviously and it formed a very high dose peak at the end of the range, and the ratio of maximum dose to the dose of the surface was greatly increased. The results of this study demonstrated that we could change the depth dose distribution of electron beam which is analogous to the heavy ion by modulating the energy of the electron and magnetic field. It means that using magnetic fields in conjunction with electron radiation therapy has great application prospect, but it also has brought new challenges for the research of dose algorithm.
Objective To analyze the differences in microbial communities in bronchoalveolar lavage fluid (BALF) from patients with simple pneumonia versus those with chronic obstructive pulmonary disease (COPD) combined with lower respiratory tract infection using metagenomic next-generation sequencing (mNGS). Methods Patients hospitalized for pulmonary infections at the First Affiliated Hospital of Xinjiang Medical University between December 2021 and March 2023 were included. Based on the presence of COPD, the patients were divided into two groups: those with simple pneumonia and those with COPD combined with lower respiratory tract infection. mNGS was employed to detect microbes in BALF, and the microbial community distribution characteristics of the two groups were analyzed. Results A total of 97 patients were included, of whom 80 (81.82%) had positive microbial detection results. The smoking index in COPD group with lower respiratory tract infection was significantly higher than that in the group with simple pneumonia (t= ?3.62, P=0.001). Differences in microbial community distributions were observed between the groups. At the genus level, 19 species of microorganisms were detected in the simple pneumoniapulmonary infection group, including 8 bacteria (42.11%), 2 fungi (10.53%), 3 viruses (15.79%), and 6 other types of microorganisms (31.58%). In contrast, 22 types of microbes were detected in COPD group with lower respiratory tract infection, including 10 bacteria (47.62%), 3 fungi (14.29%), 4 viruses (19.05%), and 4 other types of microorganisms (19.05%). Differences were also noted in reads per million (RPM) values; bacterial RPM values at the genus level were significantly higher in the COPD group during non-severe pneumonia compared to the simple pneumonia group (Z=–2.706, P=0.007). In the patients with severe pneumonia, RPM values at the genus and species levels were significantly higher than those in non-severe pneumonia (Z=?2.202, P=0.028; Z=?2.141, P=0.032). In COPD combined with severe pneumonia, bacterial RPM values were significantly higher at the species level compared to non-severe pneumonia (Z=?2.367, P=0.017). ConclusionsThere are differences in the distribution of microbial communities at the genus and species levels in BALF from patients with COPD combined with lower respiratory tract infection compared to those with simple pulmonary pneumonia. Bacteria are the predominant microbial type in both groups, but the dominant bacterial species differ between them. Simple pneumonia are primarily associated with bacterial, viral, and other types of microbial infections, while COPD combined with lower respiratory tract infection is predominantly associated with fungal and bacterial infections. RPM values may serve as an indicator of the severity of pneumonia.
Stress distribution of denture is an important criterion to evaluate the reasonableness of technological parameters, and the bite force derived from the antagonist is the critical load condition for the calculation of stress distribution. In order to improve the accuracy of stress distribution as much as possible, all-ceramic crown of the mandibular first molar with centric occlusion was taken as the research object, and a bite force loading method reflecting the actual occlusal situation was adopted. Firstly, raster scanning and three dimensional reconstruction of the occlusal surface of molars in the standard dental model were carried out. Meanwhile, the surface modeling of the bonding surface was carried out according to the preparation process. Secondly, the parametric occlusal analysis program was developed with the help of OFA function library, and the genetic algorithm was used to optimize the mandibular centric position. Finally, both the optimized case of the mesh model based on the results of occlusal optimization and the referenced case according to the cusp-fossa contact characteristics were designed. The stress distribution was analyzed and compared by using Abaqus software. The results showed that the genetic algorithm was suitable for solving the occlusal optimization problem. Compared with the reference case, the optimized case had smaller maximum stress and more uniform stress distribution characteristics. The proposed method further improves the stress accuracy of the prosthesis in the finite element model. Also, it provides a new idea for stress analysis of other joints in human body.
Functional imaging method of biological electrical characteristics based on magneto-acoustic effect gives valuable information of tissue in early tumor diagnosis, therein time and frequency characteristics analysis of magneto-acoustic signal is important in image reconstruction. This paper proposes wave summing method based on Green function solution for acoustic source of magneto-acoustic effect. Simulations and analysis under quasi 1D transmission condition are carried out to time and frequency characteristics of magneto-acoustic signal of models with different thickness. Simulation results of magneto-acoustic signal were verified through experiments. Results of the simulation with different thickness showed that time-frequency characteristics of magneto-acoustic signal reflected thickness of sample. Thin sample, which is less than one wavelength of pulse, and thick sample, which is larger than one wavelength, showed different summed waveform and frequency characteristics, due to difference of summing thickness. Experimental results verified theoretical analysis and simulation results. This research has laid a foundation for acoustic source and conductivity reconstruction to the medium with different thickness in magneto-acoustic imaging.
ObjectiveTo investigate the predictive value of preoperative red blood cell distribution width to platelet count ratio (RPR) and platelet-albumin-bilirubin (PALBI) scoring for postoperative complications after radical resection of hepatic alveolar echinococcosis (HAE). MethodsAccording to the inclusion and exclusion criteria, the clinicopathologic data of patients diagnosed with HAE and underwent radical hepatectomy in the Affiliated Hospital of Qinghai University from January 2018 to October 2022 were retrospectively collected. The risk factors affecting postoperative complications after radical hepatectomy for HAE were analyzed by univariate and multivariate unconditional logistic regression analysis, which were used to construct the nomogram. The receiver operating characteristic curve was used to evaluate the value in predicting postoperative complications by nomogram model. The discrimination of the nomogram was evaluated using Bootstrap internal 1 000 resampling and evaluated using a consistency index. The predicted postoperative complications probability by nomogram and actual postoperative complications probability were calculated by Kaplan-Meier method, and the calibration curve was drawn. The calibration ability of the nomogram model was evaluated by Hosmer-Lemeshow goodness-of-fit test. The decision curve analysis was used to evaluate clinical benefit of the nomogram model. ResultsA total of 160 patients with HAE radical hepatectomy were included, of which 105 had no postoperative complications and 55 had postoperative complications. The multivariate unconditional logistic regression analysis showed that the operation time ≥207 min, intraoperative bleeding ≥650 mL, and albumin ＜38 g/L, RPR ≥0.054, and higher PALBI grading (3 levels) were the risk factors affecting postoperative complications after HAE radical hepatectomy (OR＞1, P<0.05). Based on the risk factors, the nomogram was constructed. The area under the receiver operating characteristic curve (95%CI) predicted by the nomogram for the postoperative complications was 0.873 (0.808, 0.937), with an optimal cutoff value of 0.499. The consistency index was 0.855 for discriminating postoperative complications after HAE radical hepatectomy. The calibration curve was tested by Hosmer-Limeshow and showed a good fit between the predicted curve by the nomogram and actual curve (χ2=3.193, P=0.367), indicating that the nomogram had a good calibration ability. The decision curve analysis showed that there was a good clinical applicability within the range of 11% to 93% of the threshold probability. ConclusionsThe preoperative RPR and PALBI scoring are risk factors affecting postoperative complications after radical hepatectomy for HAE. The nomogram constructed with risk factors including RPR and PALBI has a good predictive value for postoperative complications after radical hepatectomy for HAE.
ObjectiveTo explore the relation of preoperative red blood cell distribution width (RDW) with prognosis in esophageal cancer.MethodsThe PubMed, EMbase, Web of Science, Cochrane Library, VIP, Wanfang, CNKI and SinoMed databases were searched to identify potential studies assessing the correlation between preoperative RDW and prognosis of esophageal cancer patients from establishment of databases to February 2019. The endpoint events included the overall survival (OS), cancer-specific survival (CSS) and disease-free survival (DFS). The Stata 12.0 software was applied for the meta-analysis and the hazard ratio (HR) and 95% confidence interval (CI) were calculated.ResultsA total of 10 retrospective studies involving 4 260 esophageal cancer patients from China or Japan were included. The score of Newcastle-Ottawa scale (NOS) of the included studies was more than 6 points. The results demonstrated that elevated preoperative RDW was significantly associated with poor CSS (HR=1.50, 95% CI 1.14 to 1.99, P=0.004) and DFS (HR=1.45, 95% CI 1.14 to 1.85, P=0.002), while no significant association between preoperative RDW and OS in esophageal cancer was observed (HR=1.17, 95% CI 0.95 to 1.45, P=0.143). Subgroup analysis based on the pathology revealed that preoperative RDW had high prognostic value in esophageal squamous carcinoma (ESCC) (HR=1.37, 95% CI 1.05 to 1.77, P=0.018).ConclusionPreoperative RDW may be an independent prognostic factor for Chinese and Japanese esophageal cancer patients, especially for ESCC patients. However, more prospective studies with bigger sample sizes from other countries are still needed to verify our findings.
In order to check the neck response and injury during motor vehicle accidents, we developed a detailed finite element model for human cervical spine C4-C6. This model consisted of cortical bone, cancellous bone, annulus, nucleus, ligaments and articular facet, and it also set up contact in the contacting parts for simulating the movement perfectly under frontal impact. This model could be used for stress and strain distribution after the frontal impact load was applied on this model. During the process of frontal impact, the most displacement simulated data were in the interval range of experimental data. The experimental results showed that this model for the human cervical spine C4-C6 simulated the movement under the frontal impact with fidelity, and reflected the impact dynamics response on the whole.
ObjectiveTo investigate the relationship between the red blood cell distribution width (RDW) and the severity of acute exacerbation of bronchiectasis in elderly patients.MethodsThe clinical data of 216 elderly patients with acute exacerbation of bronchiectasis admitted from January 2015 to October of 2018 were analyzed retrospectively. The severity of acute exacerbation of bronchiectasis in the elderly was evaluated by bronchiectasis severity index (BSI) score. Meanwhile, 50 elderly people receiving qualified medical examination were collected as a healthy control group in the same period. The distributions of BSI score, RDW, procalcitonin (PCT), neutrophil percentage (NEU%) and C-reactive protein (CRP) were described in the patients with different risk degree. The severity of acute exacerbation of bronchiectasis in the elderly was evaluated by BSI. The patients were divided into three groups by BSI score: a low risk group, a middle risk group, and a high risk group. The indexes were described including the distribution of stratified BSI score, RDW, PCT, NEU%, CRP at different risk levels. The correlation of each index was analyzed by Spearman correlation. The threshold value of RDW was calculated by general linear regression, and the influencing factors of BSI score were analyzed by multivariate linear regression analysis.ResultsThe higher the risk stratification, the higher the BSI score, RDW, PCT, NEU% and CRP were. RDW was positively correlated with PCT, NEU% and CRP (r values were 0.425, 0.311, 0.177, respectively, P<0.05). BSI score was positively correlated with RDW, PCT, NEU%, and CRP (r values were 0.425, 0.394, 0.650, 0.578, respectively, P<0.05). RDW was positively correlated with PSI score (r=0.425, P<0.05). The thresholds of RDW were 11.45% and 14.03%. Multiple linear regression showed that RDW, PCT, NEU% and CRP were all influential factors of BSI score and explained 52.3% of the total mutation rate.ConclusionRDW is related to the severity of acute exacerbation of bronchiectasis in the elderly, and can predict the severity of acute exacerbation of bronchiectasis in the elderly.
Missing data represent a general problem in many scientific fields, especially in medical survival analysis. Dealing with censored data, interpolation method is one of important methods. However, most of the interpolation methods replace the censored data with the exact data, which will distort the real distribution of the censored data and reduce the probability of the real data falling into the interpolation data. In order to solve this problem, we in this paper propose a nonparametric method of estimating the survival function of right-censored and interval-censored data and compare its performance to SC (self-consistent) algorithm. Comparing to the average interpolation and the nearest neighbor interpolation method, the proposed method in this paper replaces the right-censored data with the interval-censored data, and greatly improves the probability of the real data falling into imputation interval. Then it bases on the empirical distribution theory to estimate the survival function of right-censored and interval-censored data. The results of numerical examples and a real breast cancer data set demonstrated that the proposed method had higher accuracy and better robustness for the different proportion of the censored data. This paper provides a good method to compare the clinical treatments performance with estimation of the survival data of the patients. This provides some help to the medical survival data analysis.