Objective To investigate the dietary intake of preschool children in Northwest China, and provide scientific basis for studying the dietary patterns and characteristics of preschool children and formulating targeted dietary interventions. Methods Using the self-designed ^“Semi-quantitative Food Frequency Questionnaire for Preschool Children in Northwest China^“, a convenient sampling method was used to investigate the dietary intake of children aged 3 to 7 years in Northwest China. The factor analysis combined with the cluster method was used to extract the dietary pattern. Results Through factor analysis of the average daily food intake of preschool children, the results show that the KMO test value was 0.82, Bartlett’s test value was 4 528.97, and the associated probability was <0.001, so factor analysis can be performed. In order to obtain more typical factor components so that the results were easier to explain, under the guidance of nutrition experts, the first 4 common factors were finally retained for analysis, and the cumulative variance contribution rate was 62.17%. On this basis, the number of clusters was 4, and the K-means cluster analysis method was used to cluster the factor scores of various foods for preschool children. According to the proportions of various foods and the characteristics of the foods, The dietary patterns of preschool children can be divided into staple food-based dietary patterns, high-protein dietary patterns, healthy dietary patterns, and high-sugar dietary patterns. Conclusion Using factor analysis method, the scores of each food factor of preschool children were continuous variables, and the results were highly repeatable, and subsequent analysis can be carried out. The factor analysis combined with cluster analysis method extracting the dietary pattern of preschool children that had certain degree of science. According to the characteristics of the four dietary patterns extracted in this study, children's dietary interventions can be targeted to promote children's physical and mental health.

Objective To investigate the modification effect of atmospheric temperature on outpatient visits caused by O₃ in Linzhi City. Methods The daily outpatient data, the daily O₃ concentration and daily meteorological data (including daily average temperature, average relative humidity, etc.) in Linzhi City from 2018 to 2019 were collected. The distributed lag non-liner-model (DLNM) was used to quantitatively evaluate the impact of O₃ in different temperature layers on the risk of outpatient visits. Results At low temperature layers, the cumulative relative risk (CRR) of total outpatient visits and non-injury outpatient visits increased by 53.8%（4.2% -126.9%) and 59.1%（5.8% -139.2%）for every 10 μg/m³ increase of O₃ concentration, respectively. The subgroup analysis showed that for every 10 μg/m³ increase of O₃ concentration at low temperature, the CRR of patients with circulatory diseases, men, women, and people being <14 years old and 14-65 years old increased by 152.1% (15.1% - 451.9%), 58.3% (2.1%-145.5%), 49.2% (3.0% -116.1%), 39.6% (2.5% - 90.3%), and 61% (0.8%-157.1%), respectively. Conclusion The average temperature may have a modifying effect on the outpatient visits caused by O₃ in Linzhi City. In general, the cumulative risk increases as the temperature decreases.

AIM: To explore the mechanism of rejection of bioengineered keratoplasty by the laser confocal microscope and immunopathological studies.

METHODS: Retrospective case study. Five patients(5 eyes)who underwent bioengineered keratoplasty for infectious keratitis from Sep.2018 to Dec.2020 and were immunologically rejected included. All observers were monocular. Slit-lamp was used to examine corneal transparency and corneal neovascularization. The cornea was dynamically observed under laser confocal microscopy, the density of subepithelial langerhans cells and stromal inflammatory cells was recorded after graft rejection, and the contralateral eye was used as the control group for statistical analysis. The infiltration and distribution of CD4⁺ cells, CD8⁺ cells and inflammatory cells were observed after immunohistochemical staining of bioengineered corneas during corneal allograft.

RESULTS: Confocal laser microscopy showed that a large number of langerhans cells were activated under the corneal epithelium of the intraoperative eye, and the activation ratio was significantly different from that of the contralateral eye(χ²=38.29, P<0.001). The stromal layer was rich in inflammatory cells, which was significantly different from that of the contralateral eye(t=32.5, P<0.05). Immunohistochemical staining and HE staining were performed on the bioengineering corneal tissue. CD4⁺ and CD8⁺ cells were observed in all corneal stromal layers, and only one case had a large number of eosinophils.

CONCLUSION: Immunopathology of rejection after bioengineered keratoplasty confirmed that T-cell-mediated cellular immunity plays an important role in the pathogenesis, and hypersensitivity to xenoantigen may be involved in it.

AIM: To evaluate the clinical effects and safety of surgical techniques in Descemet stripping automatic endothelial keratoplasty(DSAEK)in bullous keratopathy.

METHODS: A retrospective analysis of 10 patients with bullous keratopathy treated in our hospital from December 2018 to December 2019 in our hospital, including 4 males(4 eyes), 6 females(6 eyes). Descemet stripping automatic endothelial keratoplasty(DSAEK)was performed with every patient. In addition to the conventional surgical procedures, the surgical technique such as the setting of the anterior chamber perfusion tube, the design of the incision, and the peripheral corneal puncture during the operation were performed. Follow-up for 6mo, the recovery of corneal grafts and postoperative dislocations, double anterior chambers, and other complications were observed, including best corrected visual acuity(BCVA), anterior segment optical coherence tomography, corneal endothelial cell count and incidence of postoperative complications.

RESULTS: All patients had smooth surgery, no intraoperative complications occurred, and no postoperative dislocations or interlaminar effusions occurred; postoperative intraocular pressure was normal, and the BCVA was improved to different degrees than before surgery. The symptoms such as tearing and photophobia gradually reduced from 1d after surgery, and completely relieved after 2wk. Corneal stroma edema decreased within 1mo after operation, and the central corneal thickness(596.8±19.11μm)was significantly thinner than that before operation(874.0±58.64μm). During the follow-up period, all patients were stable and the corneal grafts remained transparent, but the corneal endothelial counts were reduced to varying degrees.

CONCLUSION: The application of surgical techniques in DSAEK can significantly reduce intraoperative and postoperative complications, improve the safety of surgery, and has clinical value in bullous keratopathy.