ABSTRACT
Persistent pulmonary hypertension of the newborn(PPHN)is a disease that seriously endangers the life of the newborn caused by one or more factors.The causes mainly include respiratory distress syndrome, meconium aspiration syndrome, infection, congenital diaphragmatic hernia, etc.The pathogenesis of PPHN is still not completely clear, and neurobiochemical, internal environment, genetics and other factors are currently recognized as influencing factors.In recent years, with the rapid development and wide application of genetic testing technology, more and more studies have shown that the occurrence of PPHN may be related to the polymorphism and/or mutation of some genes.This article reviews the research progress of six gene loci that may be related to PPHN in order to provide reference for clinical research.
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Objective To explore the characteristics and clinical significance of lung function in children with mycoplasma pneumoniae pneumonia. Methods The pulmonary ventilation function of 60 cases of mycoplasma pneumoniae pneumonia was tested in the acute stage and 2 weeks after treatment by the pneumatometer made by JAEGER company in Germany. FVC, FEV1, PEF, FEF25,FEF50、FEF75 and MMEF75/25 was detected. Results In acute phase, lung function indexs (FVC, FEV1, PEF, FEF25, FEF50, FEF75, MMEF75/25) of 60 children with MPP were less than expected:(1.56 ± 0.53) L vs.(1.99 ± 0.69) L, (1.37 ± 0.47) L vs. (1.68 ± 0.57) L, (2.90 ± 0.86) L/s vs. (3.95 ± 1.08) L/s, (2.48 ± 0.67) L/s vs. (3.56 ± 0.89) L/s, (1.42 ± 0.41) L/s vs. (2.51 ± 0.64) L/s, (0.65 ± 0.20) L/s vs. (1.28 ± 0.33) L/s, (1.22 ± 0.77) L/s vs.(2.18 ± 0.61) L/s], and there were significant difference (P<0.01). In recovery period, the level of FVC, FEV1, PEF, FEF25, FEF50, FEF75, MMEF75/25 was significantly better than that in acute phase: (98.80 ± 9.34)% vs.(79.14 ± 6.28)%, (98.67 ± 8.28)% vs. (81.63 ± 6.56)%, (86.23 ± 6.86)% vs.(73.17 ± 6.21)%, (85.17 ± 7.86)% vs. (69.79 ± 8.16)%, (79.08 ± 7.99)% vs. (56.57 ± 8.77)%, (70.85 ± 7.48)% vs. (50.66 ± 9.86)%, (77.35 ± 6.81)% vs. (56.19 ± 9.61)%, P<0.01. Conclusions In the acute stage, the pulmonary function of children with MPP shows hybrid ventilation dysfunction. In the recovery period, pulmonary function index improves significantly, but there are still abnormal small airway indicators.
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This study was aimed to assess the stress distribution of different capacity of class I cavity after composite resin filling. A three-dimensional finite element made of the maxillary second molar was constructed by spiral CT scan technology. Based on this model, stress distribution in tooth was analyzed before and after post-core restorations with 5 different capacities of class I cavity. When the circle triangle of class I cavities being under 50N vertical pressures, the cavity capacity increased from 3.3 mm to 3.7 mm, the maximum tensile stress values of the composite resin restorations being 3 times those of normal tooth, which were 14.872 MPa, 16.682 MPa and 17.589 MPa, 17.307 MPa and17.912 MPa. Obviously, the effect of different capacities of class I cavity on the maximum stress value enduring ability of teeth was samll, but in the analysis model, the enduring ability of teeth was reduced when the molars were filled with resin.
Subject(s)
Humans , Composite Resins , Chemistry , Computer Simulation , Dental Stress Analysis , Finite Element Analysis , Imaging, Three-Dimensional , Models, Biological , Molar , Diagnostic Imaging , Pathology , Post and Core Technique , Root Canal Filling Materials , Chemistry , Tomography, Spiral ComputedABSTRACT
Ray casting algorithm can obtain better quality images in volume rendering, however, it presents some problems such as powerful computing capacity and slow rendering velocity. Therefore, a new fast algorithm of ray casting volume rendering is proposed in this paper. This algorithm reduces matrix computation by the matrix transformation characteristics of re-sampling points in two coordinate system, so re-sampled computational process is accelerated. By extending the Bresenham algorithm to three dimension and utilizing boundary box technique, this algorithm avoids the sampling in empty voxel and greatly improves the efficiency of ray casting. The experiment results show that the improved acceleration algorithm can produce the required quality images, at the same time reduces the total operations remarkably, and speeds up the volume rendering.
Subject(s)
Humans , Algorithms , Fourier Analysis , Image Interpretation, Computer-Assisted , Methods , Imaging, Three-Dimensional , Methods , SoftwareABSTRACT
In the examination of 3D DCE-MRA, it is the key of success or failure to measure and compute the delaying scan time accurately. Now, the timing technique used widely in clinic is test injection bolus, which is limited by inadequate perfectibility, limited spatial resolution and technique complexity. In this article is presented a technique in which contrast arrival is detected in the targeted vasculature in real time using MR fluoroscopy. Upon detection the operator triggers a 3D MR angiographic acquisition which uses an elliptical centric view order. It is shown that the view order intrinsically provides a high degree of venous suppression, a high degree of immunity to motion effects and a high degree of spatial resolution. The reliability of fluoroscopic triggering in bolus detection is shown to be over 95%. The technique provides high quality contrast-enhanced MR angiograms for many vascular regions.
Subject(s)
Humans , Contrast Media , Fluoroscopy , Methods , Image Enhancement , Methods , Imaging, Three-Dimensional , Magnetic Resonance Angiography , MethodsABSTRACT
<p><b>OBJECTIVE</b>To assess the possibility of using spirometrically controlled computed tomography (CT) to test pulmonary ventilation function.</p><p><b>METHODS</b>Spiral CT scans under the control of a spirometer were performed on 30 healthy adults. Spiral CT scan was performed at 50% vital capacity (VC) with an 8 mm slice thickness. Mean attenuation values and pixel index (PI) of lung regions were evaluated with semiautomatic evaluation software.</p><p><b>RESULTS</b>There were significant differences in PI values between four pixel intervals.</p><p><b>CONCLUSIONS</b>Spirometrically controlled spiral CT with semiautomatic evaluation software is an accurate and reproducible method of measuring lung density and PI, which has the possibility of indicating pulmonary ventilation function.</p>