Establishing a natural population prospective cohort represents a sophisticated systematic project that spans multiple disciplines and research directions, requiring comprehensive consideration of diverse factors. Both international and domestic practices have accumulated substantial experience and achievements in this field. These prospective cohorts are typically developed through collaborative efforts among research institutions, generating systematic insights into construction backgrounds, objectives, design frameworks, implementation strategies, and management protocols. This study conducts an in-depth investigation into the current status of natural population prospective cohort development globally and domestically, systematically summarizing progress in development history, current status, and research advancements. The findings aim to inform strategic planning in China’s related domains, thereby facilitating the advancement of natural population prospective cohort research.

Objective:To investigate the effect of β-elemene on mitochondrial structure and function of the A549 cells of non-small cell lung cancer(NSCLC),and to elucidate the mechanism of β-elemene in the treatment of NSCLC.Methods:The A549 cells at logarithmic growth stage were divided into blank control group(0 mng·L-1 β-elemene),low,medium and high doses of β-elemene groups(10,25 and 50 mg·L-1),and solvent control group(0.5％ethanol in equal volume).After treatment for 24 h,the cell activities in various groups were detected by MTT assay;the morphology changes of mitochondria in the cells in various groups was observed by transmission electron microscope;the levels of adenosine 5′-triphosphate(ATP)in the cells in various groups were detected by colorimetry;the mitochondrial membrane potential of the A549 cells in various groups were detected by JC-1 flow cytometry;mitochondrial membrane permeability transfer hole assay was used to detect the mitochondrial membrane permeabilities of the cells in various groups.Results:The MTT results showed that compared with blank control group,the cell activities in low,medium and high doses of β-elemene groups were decreased gradually(P＜0.05),while the cell activity in solvent control group had no significant change,and the difference was not significant(P＞0.05).The transmission electron microscope results showed that compared with blank control group,the mitochondria of A549 cells in low,medium and high doses ofβ-elemene groups showed swelling,vacuolation,disordered arrangement and dissolution,while the mitochondrial morphology of the A549 cells in solvent control group had no significant changes.The colorimetric method results showed that compared with blank control group,the ATP levels in the A549 cells in low,medium and high dose β-elemene groups were gradually decreased(P＜0.05),while the ATP level in the A549 cells in solvent control group had no significant change,and the difference was not significant(P＞0.05).The JC-1 flow cytometry method results showed that compared with blank control group,the mitochondrial membrane potential of the A549 cells in low,medium and high doses ofβ-elemene groups were decreased,and the percentages of the cells in Q2-4 region were increased(P＜0.05);the percentage of the A549 cells in the Q2-4 region in solvent control group had no significant change.The results of mitochondrial membrane permeability transfer hole experiment showed that compared with blank control group,the mitochondrial membrane permeabilities of the A549 cells in low,medium and high doses of β-elemene groups were increased,and the percentages of the cells in M4 region were increased(P＜0.05);the mitochondrial membrane permeability of the A549 cells and the percentage of the M4 cells in solvent control group had no significant changes,and the difference was not significant(P＞0.05).Conclusion:β-elemene can inhibit the proliferation of the A549 cells,and the mechanism may be that the mitochondrial structure of A549 cells is damaged by reducing the level of ATP and mitochondrial membrane potential,changing the mitochondrial morphology and increasing the mitochondrial membrane permeability.

OBJECTIVE To investigate the selection strategy for recipient vessels in free flap reconstruction of head and neck defects.METHODS A retrospective analysis was conducted on 96 patients who underwent 99 free flap reconstructions for head and neck defects between January 2020 and December 2024.Recipient vessel selection,flap survival,and postoperative complications were analyzed based on defect location and flap type.RESULTS In 99 cases microvessel anastomosis,the recipient arteries were superior thyroid artery in 49 branches,facial artery in 28 branches,superficial temporal artery in 14 branches,lingual artery in 5 branches.external carotid artery in 1 branch,transverse cervical artery in 1 branch,and superior laryngeal artery in 1 branch.Venous anastomosis was performed in 104 branches,with 94 cases in 1 venous anastomosis and 5 cases in 2 venous anastomoses.The recipient veins selected were facial vein in 62 branches,external jugular vein in 21 branches,superficial temporal vein in 12 branches,retromandibular vein in 3 branches,middle thyroid vein in 2 branches,internal jugular vein in 2 branches,middle temporal vein in 1 branch,and superior thyroid vein in 1 branch.Complete flap necrosis occurred in 5 cases,and partial necrosis occurred in 4 cases.When the recipient vessels were deficient,the lingual artery was chosen in 3 cases,the facial artery in 1 case,the external jugular vein in 3 cases,the internal jugular vein with end-to-side anastomosis in 1 case,and the common facial vein with end-to-side anastomosis in 1 case.CONCLUSION In free flap reconstruction for head and neck defects,the superior thyroid artery,facial artery,and superficial temporal artery are commonly used as recipient arteries,while the facial vein,external jugular vein,and superficial temporal vein are frequently selected as recipient veins.When recipient vessels are scarce,the ipsilateral lingual artery,transverse cervical artery,and main trunk of the internal jugular vein can serve as alternative recipient vessels.

OBJECTIVE To explore the application of the facial artery musculomucosal(FAMM)flap for the reconstruction of head and neck defects.METHODS A retrospective analysis of 9 patients with head and neck defects reconstructed with the FAMM at the Department of Otolaryngology Head and Neck Surgery,Beijing Tongren Hospital,Capital Medical University,between May 2019 and March 2024.Data regarding defect location,flap size,and postoperative complications were analyzed.RESULTS The defect locations among the nine patients were as follows:hard palate(3 cases),soft palate(2 cases),nasal septum and columella(1 case),oropharyngeal lateral wall(1 case),retromolar region and oropharyngeal lateral wall(1 case),and lower lip(1 case).The FAMM flap sizes ranged from 1.5 cm×2.5 cm to 4 cm×6 cm.Primary closure of the donor site was achieved by direct intermittent suturing in 7 cases;one case was repaired using acellular dermal matrix,and 1 case was repaired using a buccal fat pad graft.Postoperatively,eight flaps survived completely,while 1 flap experienced necrosis.None of the patients developed trismus or malocclusion.CONCLUSION The FAMM flap is suitable for reconstructing defects of the hard palate,soft palate,lower lip or oropharyngeal lateral wall.With reliable blood supply and an intraoral donor site,it offers relatively favorable aesthetic outcomes and is worthy of widespread adoption.

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.

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.