In order to extract the outlines of macular edema from OCT images of macular, and estimate the volume of edema, we have to accurately segment the macular edema region. In this paper, an improved PCNN algorithm was proposed to conduct the above process. Combined with the adaptive base threshold, and the simplified neural network parameters, a binary image of macular edema was produced. According to the principle of maximum image entropy, the optimal number of iterations was determined as 8, which was evaluated by its misclassification rate. Simulation showed that the proposed algorithm could extract the macular edema region rapidly and accurately, providing the basis for further OCT image analysis.
Algorithms ; Fluorescein Angiography ; methods ; Humans ; Macular Edema ; diagnostic imaging ; Radiography ; Tomography, Optical Coherence ; methods

Objective:To evaluate the rationality of the "Sandwich Principle teaching mode" adopted in our teaching of internal medicine and verify the necessity of its "Intergroup intersecting discussion".Methods:33 students majoring in traditional Chinese medicine were divided into control group (taught by standard process of sandwich principle) and experiment group (taught by simplified process of sandwich principle). The Dundee Ready Education Environment Measure (DREEM) was used to evaluate students' feelings toward the two teaching modes.Results:The total score of DREEM in the control group was higher than that in the experiment group, with statistically significant difference; the total score in the academic perception subscale in the control group was higher than that in the experiment group, among which the scores of "I have faith in passing the exam this year" and other 2 items were better than that in the experiment group, with statistically significant difference ( P<0.05); there were no statistical difference in the total scores of other perception subscales between the two groups( P>0.05), but the scores of the 9 items including "the atmosphere is very harmonious in the clinical teaching process" in the control group were significantly better than those in the experiment group, with statistically significant difference( P<0.05). Conclusion:The teaching mode of Sandwich Principle can create a positive and effective learning environment for supporting students. "Intergroup intersecting discussion" can encourage students to actively participate in the teaching process, and help increase their academic confidence and sense of achievement in learning. It is also helpful to build a harmonious teacher-student relationship and create a relaxing and pleasant learning environment so that students can gain a better learning experience. Therefore, "Intergroup intersecting discussion" is indispensable in medical teaching.

ObjectiveTo investigate the therapeutic effect of Dayuanyin on acute lung injury induced by H1N1 infection and decipher the potential mechanism. MethodThe constituents in Dayuanyin were analyzed by ultra-high performance liquid chromatography-quadrupole-exactive orbitrap mass spectrometry （UHPLC-Q-Exactive Orbitrap MS）. Forty-eight female BALB/c mice were randomized into normal， model， oseltamivir （19.5 mg·kg^-1）， and low-， medium-， and high-dose （2.73， 5.46， 10.92 g·kg^-1） Dayuanyin groups. The normal and model groups were administrated with deionized water by gavage， and the other groups were administrated with the corresponding drugs by gavage. On day 3 of drug administration， the normal group received nasal inhalation of normal saline， and the other groups were inoculated intranasally with A/RP/8/34 （H1N1） for the modeling of influenza virus infection. Mice were administrated with drugs continuously for 7 days and weighed daily. Sampling was performed 12 h after the last administration， and the lung tissue was weighed to calculate the lung index. Hematoxylin-eosin staining was performed to observe the pathological and morphological changes of the lung tissue and bronchi. The cytometric bead array （CBA） was used to measure the serum levels of interferon-gamma （IFN-γ）， C-X-C motif ligand 1 （CXCL1）， tumor necrosis factor-alpha （TNF-α）， chemokine ligand 2 （CCL2）， interleukin-12p70 （IL-12p70）， chemokine ligand 5 （CCL5）， interleukin-1β （IL-1β）， chemokine （C-X-C motif） ligand 10 （CXCL10）， granulocyte-macrophage colony-stimulating factor （GM-CSF）， interleukin-10 （IL-10）， interferon-beta （IFN-β）， interferon-alpha （IFN-α）， and interleukin-6 （IL-6）. According to the results of mass spectrometry and network pharmacology， we analyzed the mechanism of Dayuanyin in treating acute lung injury caused by H1N1. The protein levels of extracellular signal-regulated kinase 1/2 （ERK1/2）， p38 mitogen-activated protein kinase （p38 MAPK）， nuclear factor-kappa B （NF-κB）， and their phosphorylated forms were determined by Western blot. The mRNA levels of myeloid differentiation factor 88 （MyD88）， Toll-like receptor 3 （TLR3）， Toll-like receptor 7 （TLR7）， and Toll-like receptor 8 （TLR8） in the lung tissue were measured by Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）. ResultA total of 57 compounds， including paeoniflorin and baicalein， were detected in Dayuanyin. Compared with the normal group， the model group showed decreased body weight （P<0.01）， lung edema and hemorrhage， increased lung index （P<0.01）， and elevated levels of IFN-γ， IL-12p70， CCL5， IL-1β， CXCL10， GM-CSF， IFN-β， and IL-6 （P<0.01）. Compared with the model group， Dayuanyin attenuated alveolar wall thickening， capillary congestion， and immune cell infiltration， reduced the alterations in body weight and lung index （P<0.01）， and down-regulated the protein levels of IFN-γ， IL-12p70， CCL5， IL-1β， CXCL10， GM-CSF， IFN-β， and IL-6 （P<0.01）. A total of 57 key genes were predicted by network pharmacological analysis， of which the MAPK signaling pathway was the main target signaling pathway. Compared with the normal group， the model group showed up-regulation in the protein levels of phosphorylation （p）-ERK1/2， p-p38 MAPK， and p-NF-κB （P<0.01） and the mRNA levels of TLR7， TLR8， MyD88， and TLR3 （P<0.05， P<0.01）. Compared with the model group， Dayuanyin lowered the phosphorylation levels of ERK1/2， p38 MAPK， and NF-κB p65 in a dose-dependent manner （P<0.01） and down-regulated the mRNA levels of TLR3， TLR7， TLR8， and MyD88 （P<0.01）. ConclusionDayuanyin can prevent and control H1N1 infection-induced acute lung injury by inhibiting the TLR/MAPK/NF-κB signaling pathway.

Objective:To investigate the epidemiological and clinical characteristics of human parainfluenza viruses (HPIVs) infection among hospitalized children with community-acquired pneumonia (CAP) in China, and provide basic data for diagnosis, treatment and prevention of HPIVs infection.Methods:From November 2014 to February 2020, 5 448 hospitalized children with CAP were enrolled in 14 hospitals in 11 provinces and municipalities directly under the Central Government in southern China and northern China. Nasopharyngeal aspirates or throat swabs were collected, and the nucleic acids of 18 types respiratory viruses including HPIV1-4 were screened by suspension array technology. Demographic data and clinical information were collected for statistical analysis.Results:The total detection rate of HPIVs in 5 448 children with CAP was 8.83% (481/5 448), and the detection rate in males was higher than that in females (62.79% vs. 37.21%; χ2=0.000, P=0.992). The detection rate of HPIVs in 1~< 3 years age group was higher than that in other age groups, and the difference was statistically significant ( χ2=61.893, P<0.001). The detection rate of HPIVs in the northern region was higher than that in the southern region (9.02% vs 8.65%), but the difference was not statistically significant ( χ2=0.239, P=0.625). The prevalence of HPIV1-4 in northern and southern China was not completely same. HPIV1 was mainly prevalent in autumn in both northern and southern regions. HPIV2 was prevalent in summer in northern China, and the detection rate was low in southern China. HPIV3 reached its peak in both spring and summer in both northern and southern China, but its duration was longer in southern China than in northern China. HPIV4 is mainly popular in autumn in both southern China and northern China. Among 481 children infected with HPIVs, 58.42% (281/481) were infected with HPIV alone, and the main clinical manifestations were cough (90.75%) and fever (68.68%). Out of the HPIV-positive cases, 42.62% (205/481) were co-infected with another type of HPIV or a different virus, while 11.43% (55/481) had co-infections with two or more different viruses. HPIV3 was the most common type of co-infection with other viruses. HPIV3 infection accounted for the largest proportion (76.80%) in 47 HPIVs-positive children with severe pneumonia. Conclusions:HPIVs is one of the most important pathogens causing CAP in children in China, and children under 3 years of age are the main populations of HPIVs infection. The prevalence characteristics of all types of HPIVs in children in the north and south are not completely same. HPIV3 is the dominant type of HPIV infections and causes more severe diseases.