Objective To observe the characteristics of morphological development of premature retina at 33-46 weeks of gestational corrected age (GCA). Methods A total of 268 premature infants were divided into 7 groups according to the GCA (33-34，35-36，37-38，39-40，41-42，43-44 and 45-46 weeks). The ocular fundus of those infants were recorded and analyzed by an indirect ophthalmoscopelinked imaging system. Results As GCA increases, noticeable macular morphological changes occurred and recorded in 96% of infant at 45-46 weeks of GCA. Retinas were gradually vascularized at 41-42 weeks (nasal retina) or 43-44 weeks (area Ⅲ,temporal retina), and pigmented in 84% of infant at 45-46 weeks of GCA. Conclusion Macular morphological patterns, retinal blood vessels and pigments continue to develop in postnatal premature infants.
Objective To observe the characteristics of images of ocular fundus obtained by computer-assisted imaging system of binocular indirect ophthalmosco p y (CABIO) in the healthy premature infants and the ones with retinopathy of prem aturity(ROP), and evaluate the value of the clinical practice of CABIO in ROP s creening. Methods From January, 2006 to December, 2006, we exa mined 150 prematur e infants in ROP screening procedure by using the computerassisted imaging sys t em of binocular indirect ophthalmoscope, beginning at the infantsprime;age of postn a tal 4-6 weeks or the corrected age above 32 weeks. The follow-up duration was co nfirmed according to the first examination results. The procedure of the operati on was recorded and the typical pictures were shot to obtain the images of the o cular fundus of the healthy premature infants and the ones with ROP. The charact eristics of the images were retrospectively analyzed and compared. Resu lts The typical images of normal ocular fundus and that with ROP in the 150 premature i nfants were successfully obtained by indirect ophthalmoscope. In normal fundus o f infants, the color of optic disc was pale, peripheral retina was not completel y vascularized and presented gray-tone in color;while all stages of ROP present ed dif ferent appearances under the indirect ophthalmoscope. Conclusions Computer-ass isted imaging system of the binocular indirect ophthalmoscopy can clearly observ e the characteristics of normal ocular fundus of premature infants and the ocula r fundus with ROP, and can save the objective examination results, which may pro vide significant references in screening and treating ROP.
Objective To study the predictive value of inspiratory capacity (IC) and total lung capacity (TLC) on acute exacerbation of patients with chronic obstructive pulmonary disease (COPD). Methods The in-patients due to acute exacerbation of COPD (AECOPD) from February 2017 to March 2019 were recruited in the study. Research data were collected during the recovery period and one year follow-up , and the patients were divided into two groups according to whether there was another acute exacerbation. Results A total of 372 patients were included in the study. In the patients with acute exacerbation, the age and TLC as a percentage of the expected value (TLC%pred) were higher, while IC as a percentage of the expected value (IC%pred) and the ratio of IC and TLC (IC/TLC) were lower. Univariate analysis revealed that IC/TLC≤25% was a significant predictor of acute exacerbation (P<0.001) after the AECOPD patients were discharged. Multivariable analysis revealed age (OR=1.25, 95%CI 1.17 to 1.44, P<0.001) and IC/TLC≤25% (OR=1.68, 95%CI 1.36 to 2.07, P<0.001) were independent risk factors of AECOPD.Conclusions Decreased IC/TLC significantly correlates with poor prognosis of COPD. IC/TLC≤25% is an independent risk factor for acute exacerbation.
Objective To observe the development of cone/rod functions in children with retinopathy of prematurity (ROP) after laser photocoagulation. Methods 30 ROP patients (60 eyes) treated with laser photocoagulation (case group) and 30 preterm infants (60 eyes) without ROP (control group) were enrolled in this study. Flash Electroretinogram (F-ERG) was performed on all the children, and the response of rod cells and cone cells, maximal mixed responses and oscillatory potentials were recorded. Results Compared with the control group, the amplitude of response of rod cells was obviously decreased (t=-2.385, P＜0.05), while the latency phase of rod cells was obviously prolonged (t=-2.799,P＜0.05); the amplitudes of a-and b-wave of maximal response were significantly decreased in the case group (t=-2.967, -4.037; P＜0.05). But there was no significant difference of amplitudes(t=-1.402) and latency phase (t=-1.637,0.465)of b-/a-wave of the maximal mixed response between two groups(P＞0.05). In the response of cone cells, there was no significant difference of the latency phase (t=1.222) and amplitude (t=-0.636)of a-wave as well as amplitude (t=-1.927) of b-wave between two groups (P＞0.05). The latency phase of b-wave of cone cells in the case group was longer than that in the control group (t=-2.466,P＜0.05). Conclusions Compared to no-ROP preterm infant retina, laser-treated ROP retina has normal cone function development and delayed rod function development.
It is the main method for amplifying the specific gene to use the nucleic acid amplification system to accomplish polymerase chain reaction (PCR). The temperature retard between heat source and sample exists in the heating and cooling progresses of most nucleic acid amplification system. The retard would result in the problem that the sample would take a long time to reach the set temperature and the problem would reduce the speed of integrate reaction. Non-specific products would be created in the process of amplification when the sample cannot reach the set temperature within a certainly time and the amplified efficiency would be reduced. A miniaturization nucleic acid amplification system heated by air was designed in this study according to the principle of air-heated nucleic acid amplification system and the characteristics of the PCR instrument Smart-cycler. The heat transfer process was analyzed and the heat transfer time was calculated. The actual temperature was measured in real time, and the temperature curves were fitted. The heating time was chosen by analysis results and data fitting and the air temperature was changed, while the sample temperature was recorded. The retard between sample and air was optimized by choosing the best curve of sample temperature. The temperature retard between sample and air was reduced sharply and the required time of integrate progress is shortened to 50%. We confirmed from the amplification experiment of Listeria monocytogenes that the improved system could complete 3 cycles within 4 minutes, and the amplification effect was good. The amplification speed and effect could be improved effectively by optimizing the delay between sample and air.
One of the most important environmental cleanliness indicators is airborne microbe. However, the particularity of clean operating environment and controlled experimental environment often leads to the limitation of the airborne microbe research. This paper designed and implemented a microenvironment test chamber for airborne microbe research in normal test conditions. Numerical simulation by Fluent showed that airborne microbes were evenly dispersed in the upper part of test chamber, and had a bottom-up concentration growth distribution. According to the simulation results, the verification experiment was carried out by selecting 5 sampling points in different space positions in the test chamber. Experimental results showed that average particle concentrations of all sampling points reached 107 counts/m3 after 5 minutes’ distributing of Staphylococcus aureus, and all sampling points showed the accordant mapping of concentration distribution. The concentration of airborne microbe in the upper chamber was slightly higher than that in the middle chamber, and that was also slightly higher than that in the bottom chamber. It is consistent with the results of numerical simulation, and it proves that the system can be well used for airborne microbe research.
Artifacts produced by chest compression during cardiopulmonary resuscitation (CPR) seriously affect the reliability of shockable rhythm detection algorithms. In this paper, we proposed an adaptive CPR artifacts elimination algorithm without needing any reference channels. The clean electrocardiogram (ECG) signals can be extracted from the corrupted ECG signals by incorporating empirical mode decomposition (EMD) and independent component analysis (ICA). For evaluating the performance of the proposed algorithm, a back propagation neural network was constructed to implement the shockable rhythm detection. A total of 1 484 corrupted ECG samples collected from pigs were included in the analysis. The results of the experiments indicated that this method would greatly reduce the effects of the CPR artifacts and thereby increase the accuracy of the shockable rhythm detection algorithm.
Detection and classification of malignant arrhythmia are key tasks of automated external defibrillators. In this paper, 21 metrics extracted from existing algorithms were studied by retrospective analysis. Based on these metrics, a back propagation neural network optimized by genetic algorithm was constructed. A total of 1,343 electrocardiogram samples were included in the analysis. The results of the experiments indicated that this network had a good performance in classification of sinus rhythm, ventricular fibrillation, ventricular tachycardia and asystole. The balanced accuracy on test dataset reached up to 99.06%. It illustrates that our proposed detection algorithm is obviously superior to existing algorithms. The application of the algorithm in the automated external defibrillators will further improve the reliability of rhythm analysis before defibrillation and ultimately improve the survival rate of cardiac arrest.