AIM: To report three cases of viral keratitis caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).METHODS: Slit lamp, intraocular pressure, corneal fluorescence staining, anterior segment photography, in vivo confocal microscopy(IVCM), and routine fundus screening were performed in the three confirmed patients. Treatment involved Ganciclovir, artificial tears and glucocorticoid eye drops.RESULTS: Three patients with SARS-CoV-2 keratitis(SCK)recovered well after standard treatment.CONCLUSION: SARS-CoV-2 keratitis typically presents as corneal subepithelial infiltration and can result in a decrease in corneal subepithelial nerve fiber density and an increase in dendritic cells(DC). Antiviral therapy in combination with glucocorticoid has proven to be effective.

Objective:To investigate the effects of wza gene deletion in Klebsiella pneumoniae on capsule formation ability and bacteriophage sensitivity. Methods:The wza deletion mutant strain was constructed through a temperature-sensitive plasmid-mediated homologous recombination. The growth curves of W14 and Δ wza were detected by measuring the optical density OD 600. In order to analyze the effect of gene wza on bacterial capsule formation, wild-type strain W14 and Δ wza mutant strain were detected by transmission electron microscope, and their capsule contents were measured by quantifying the uronic acid contents. The plaque assay was used to detect bacterial sensitivity to bacteriophage in wild-type strain W14 and Δ wza mutant strain. The t test was used to compare whether there were differences in the contents of uronic acid in the capsules of wild-type strain W14 and Δ wza mutant strain. Results:The PCR results revealed that the Δ wza mutant strain was successfully constructed. Compared with wild-type strain W14, the growth curves of Δ wza on the solid plates demonstrated a slightly slower growth. However, no difference in growth was observed among wild-type strain W14 and Δ wza mutant strains in LB broth. The transmission electron microscope results showed that wza gene deletion resulted in the loss of capsule in bacteria. The uronic acid content assay suggested that the capsule content was significantly decreased in Δ wza mutant strain (45.963±2.795) μg/ml compared with wild-type strain W14 (138.800±5.201) μg/ml. There was a statistical difference between the two groups ( t=27.233, P<0.001). The plaque assay indicated that bacteria lost its sensitivity to bacteriophage when gene wza was deleted. Conclusion:Deletion of the wza gene impairs bacterial capsule formation ability and can affect bacterial sensitivity to bacteriophage phiW14.

Objective:To express and purify the phage depolymerase from hypervirulent Klebsiella pneumoniae (hv Kp) serotype K1 and validate its function. Methods:Phage that infected serotype K1-type hv Kp was isolated from hospital sewage. The biology and morphology of the phage were determined by plaque assay and transmission electron microscopy. The whole genome of the phage was sequenced by the Illumina HiSeq 2500 platform. The presence of depolymerase was determined by observing the plaque halo. Bioinformatic analysis and prokaryotic protein expression system were further used to predict and identify phage depolymerase. The depolymerase gene fragment was obtained by PCR and cloned into the pET28a expression vector, and the expression and purification of the depolymerase were completed in strain BL21. The depolymerase activities on the capsular polysaccharide of serotype K1-type hv Kp clinical isolates were detected by plaque assay and low-speed centrifugation assay. Results:A lytic phage (phiA2) that infected serotype K1-type hv Kp clinical isolate was isolated from hospital sewage. It was typical of the Caudovirales order and Autographiviridae family, and its whole genome was 43 526 bp in length and contained 51 coding domain sequences. The phage phiA2-derived depolymerase phiA2-dep was predicted, expressed and purified. The plaque assay and low-speed centrifugation assay indicated that the depolymerase phiA2-dep had good lytic activity on the capsular polysaccharide of serotype K1-type hv Kp clinical isolates. Conclusion:Depolymerase phiA2-dep can specifically degrade the capsular polysaccharide of serotype K1-type hv Kp, which has potential application value in treating bacterial infection.

China prospective multicenter birth cohort (Prospective Omics Health Atlas birth cohort, POHA birth cohort) study was officially launched in 2022. This study, in collaboration with 12 participating units, aims to establish a high-quality, multidimensional cohort comprising 20 000 naturally conceived families and assisted reproductive families. The study involves long-term follow-up of parents and offspring, with corresponding biological samples collected at key time points. Through multi-omics testing and analysis, the study aims to conduct multi-omics big data research across the entire maternal and infant life cycle. The goal is to identify new biomarkers for maternal and infant diseases and provide scientific evidence for risk prediction related to maternal diseases and neonatal health.

Objective The risk evaluation indicators for the occurrence of diaphragm dysfunction in ICU patients was constructed to provide a reference for the establishment of the disease risk evaluation tools for diaphragm dysfunction.Methods The literature related to diaphragm dysfunction from CNKI,Wanfang Data,PubMed,Embase and Web of Science from the establishment of databases to November 11 th,2022 was systematically searched.After the first draft was determined through the literature review method,the first draft of the indicators was revised by brainstorming,with the opinions of 10 medical and nursing experts from May to June 2023.From June to July 2023,the content and weight of risk evaluation indicators of diaphragmatic dysfunction in ICU patients were determined through expert letter inquiry and hierarchical analysis.Results 35 experts completed the first round of letter inquiry,and 34 experts completed the second round of letter inquiry.The recovery rates of the valid questionnaires in the 2 rounds of expert correspondence were 92.1％and 97.1％,respectively,and the expert authority coefficients were 0.884 and 0.904,respectively,and the Kendall harmony coefficients of all indicators were 0.356～0.570 and 0.369～0.604,respectively(all P＜0.001).The final constructed risk evaluation indicators of diaphragm dysfunction in ICU patients includes 7 first-level indicators,34 secondary indicators and 34 tertiary indicators.Conclusion The risk evaluation index of diaphragm dysfunction in ICU patients constructed in this study is comprehensive,specific,scientific and applicable,which can guide medical staff to conduct early risk evaluation of diaphragm function in ICU patients,and provide references for the establishment of disease risk assessment tools for diaphragm function.

Objective:To investigate the effects of wza gene deletion in Klebsiella pneumoniae on capsule formation ability and bacteriophage sensitivity. Methods:The wza deletion mutant strain was constructed through a temperature-sensitive plasmid-mediated homologous recombination. The growth curves of W14 and Δ wza were detected by measuring the optical density OD 600. In order to analyze the effect of gene wza on bacterial capsule formation, wild-type strain W14 and Δ wza mutant strain were detected by transmission electron microscope, and their capsule contents were measured by quantifying the uronic acid contents. The plaque assay was used to detect bacterial sensitivity to bacteriophage in wild-type strain W14 and Δ wza mutant strain. The t test was used to compare whether there were differences in the contents of uronic acid in the capsules of wild-type strain W14 and Δ wza mutant strain. Results:The PCR results revealed that the Δ wza mutant strain was successfully constructed. Compared with wild-type strain W14, the growth curves of Δ wza on the solid plates demonstrated a slightly slower growth. However, no difference in growth was observed among wild-type strain W14 and Δ wza mutant strains in LB broth. The transmission electron microscope results showed that wza gene deletion resulted in the loss of capsule in bacteria. The uronic acid content assay suggested that the capsule content was significantly decreased in Δ wza mutant strain (45.963±2.795) μg/ml compared with wild-type strain W14 (138.800±5.201) μg/ml. There was a statistical difference between the two groups ( t=27.233, P<0.001). The plaque assay indicated that bacteria lost its sensitivity to bacteriophage when gene wza was deleted. Conclusion:Deletion of the wza gene impairs bacterial capsule formation ability and can affect bacterial sensitivity to bacteriophage phiW14.

Objective:To express and purify the phage depolymerase from hypervirulent Klebsiella pneumoniae (hv Kp) serotype K1 and validate its function. Methods:Phage that infected serotype K1-type hv Kp was isolated from hospital sewage. The biology and morphology of the phage were determined by plaque assay and transmission electron microscopy. The whole genome of the phage was sequenced by the Illumina HiSeq 2500 platform. The presence of depolymerase was determined by observing the plaque halo. Bioinformatic analysis and prokaryotic protein expression system were further used to predict and identify phage depolymerase. The depolymerase gene fragment was obtained by PCR and cloned into the pET28a expression vector, and the expression and purification of the depolymerase were completed in strain BL21. The depolymerase activities on the capsular polysaccharide of serotype K1-type hv Kp clinical isolates were detected by plaque assay and low-speed centrifugation assay. Results:A lytic phage (phiA2) that infected serotype K1-type hv Kp clinical isolate was isolated from hospital sewage. It was typical of the Caudovirales order and Autographiviridae family, and its whole genome was 43 526 bp in length and contained 51 coding domain sequences. The phage phiA2-derived depolymerase phiA2-dep was predicted, expressed and purified. The plaque assay and low-speed centrifugation assay indicated that the depolymerase phiA2-dep had good lytic activity on the capsular polysaccharide of serotype K1-type hv Kp clinical isolates. Conclusion:Depolymerase phiA2-dep can specifically degrade the capsular polysaccharide of serotype K1-type hv Kp, which has potential application value in treating bacterial infection.

Objective To compare the effect of internal iliac artery block using balloon of different properties in cesarean section for delivery female patients with pernicious placenta previa(PPP).Methods The clinical data of 82 delivery female patients with PPP were retrospectively analyzed.The patients were divided into observation group(n=40)and control group(n=42).The patients of the observation group received compliant Fogarty balloon block of bilateral internal iliac arteries,while the patients of the control group received non-compliant balloon block of bilateral internal iliac arteries.The preoperative and postoperative systolic blood pressure and heart rate,X-ray fluoroscopy time,fetal body surface radiation dose,time spent for cesarean section,intraoperative blood loss amount and blood transfusion quantity,uterine artery embolization rate,hysterectomy rate,1-,5-,and 10-minute neonatal Apgar scores,postoperative hospital stay,and surgery-related complications were compared between the two groups.Results In all patients of both groups,the uterus was successfully preserved and the bilateral internal iliac artery balloon obstruction-assisted cesarean section was successfully accomplished.After the balloon catheter was withdrawn,uterine artery embolization was carried out in some patients,and no patient received ovarian artery embolization and hysterectomy.No statistically significant differences in preoperative,postoperative systolic blood pressure and heart rate existed between the two groups,but in both groups the postoperative systolic blood pressure and heart rate were lower than their preoperative values(all P＜0.05).No statistically significant differences in X-ray fluoroscopy time,fetal body surface radiation dose,uterine artery embolization rate,hysterectomy rate,1-,5-,and 10-minute neonatal Apgar scores,and postoperative hospital stay existed between the two groups.In the observation group the time spent for cesarean section,intraoperative blood loss amount and blood transfusion quantity were lower than those in the control group(all P＜0.05).The difference in the incidence of balloon obstruction-related complications between the two groups was not statistically significant.Conclusion In cesarean section for delivery female patients with PPP,balloon block of bilateral internal iliac,regardless of using compliant Fogarty balloon catheter or non-compliant balloon catheter,is clinically safe and effective.However,the use of compliant Fogarty balloon catheter is superior to the use of non-compliant balloon catheter in reducing the cesarean section operative time,intraoperative blood loss amount,and intraoperative blood transfusion quantity.

This paper interprets the background, content overview and characteristics, clinical practice significance and disciplinary development of Nursing Standards for Clinical Operation Techniques in Critical Care Ultrasound (hereinafter referred to as the Standards) and puts forward reflections on the clinical application of the Standards, aiming to improve the critical care ultrasound techniques of clinical nursing staff, solve nursing challenges and make clinical nursing ultrasound techniques more scientific, standardized and homogenized.

Objective:To comprehensively search and summarize the evidence on critical ultrasound nursing practice training courses, with the aim of providing a basis for critical ultrasound nursing practice training.Methods:Taking the evidence-based clinical translation model of Fudan University Centre for Evidence-based Nursing as the theoretical framework, the evidence was retrieved, evaluated, and summarized to determine the evidence to be introduced into clinical practice, forming a training program for critical ultrasound nursing practice. From July to August 2023, 25 experts from 10 provinces/municipalities across the country were selected for two rounds of consultation to determine the practical training course system for critical ultrasound nursing.Results:A total of 14 articles were included, including one clinical decision, nine expert consensus, and four systematic reviews. In the two rounds of consultation, the positive coefficients of experts were 90.0% (27/30) and 92.6% (25/27), the authority coefficients of experts were 0.956 and 0.964, and the coefficients of Kendall's harmony were 0.303 and 0.350 ( P<0.01), respectively. The final practical training course system for critical ultrasound nursing included five first-level indicators, 25 second-level indicators, and 67 third-level indicators. Conclusions:Ultrasound examination is a complex skill. The construction method of the practical training course system for critical ultrasound nursing is scientific, reasonable, with strong practicality in content, which can provide reference for the development and evaluation of critical ultrasound nursing training courses.