Human Umbilical Cord Mesenchymal Stem Cells Improve Lung Function in Chronic Obstructive Pulmonary Disease Rat Model Through Regulating Lung Microbiota.

BACKGROUND: The use of human umbilical cord mesenchymal stem cells (UC-MSCs) has shown promise in improving the pathophysiological characteristics of rats with chronic obstructive pulmonary disease (COPD). However, more research is needed to understand the exact mechanism behind their therapeutic effects and their impact on lung microbiota. METHODS: To investigate this, rats were randomly assigned to one of 3 groups: Control, COPD + vehicle, and COPD + UC-MSCs group. Lung function changes after UC-MSCs therapy were evaluated weekly for 6 weeks. Additionally, lactate dehydrogenase (LDH), TNF (tumor necrosis factor)-α, IL (interleukin)-6, and IL-1ß level in bronchoalveolar lavage fluid (BALF) were analyzed. Arterial blood gas and weight were recorded. Hematoxylin and eosin (HE) staining was used to examine lung pathology, while changes in the lung microbiota were evaluated through 16S rRNA sequencing. RESULTS: The administration of UC-MSCs in rats led to a progressive amelioration of COPD, as demonstrated by enhanced lung function and reduced inflammatory response. UC-MSCs treatment significantly altered the structure and diversity of the lung microbiota, effectively preventing microbiota dysbiosis. This was achieved by increasing the abundance of Bacteroidetes and reducing the levels of Proteobacteria. Additionally, treatment with UC-MSCs reduced the activation of pathways associated with COPD, including microbial metabolism, ABC transporters, and Quorum sensing. The group of UC-MSCs showed increased metabolic pathways, such as amino acid biosynthesis, purine metabolism, starch and sucrose metabolism, and biosynthesis of secondary metabolites, compared to the COPD group. CONCLUSIONS: The use of UC-MSCs was found to reduce inflammation and improve lung function in rats with COPD. The mechanism may be related to the lung microbiota, as UC-MSCs improved the communities of lung microbiota and regulated dysregulated metabolic pathways.

Long-read sequencing reveals the structural complexity of genomic integration of HPV DNA in cervical cancer cell lines.

BACKGROUND: Cervical cancer (CC) causes more than 311,000 deaths annually worldwide. The integration of human papillomavirus (HPV) is a crucial genetic event that contributes to cervical carcinogenesis. Despite HPV DNA integration is known to disrupt the genomic architecture of both the host and viral genomes in CC, the complexity of this process remains largely unexplored. RESULTS: In this study, we conducted whole-genome sequencing (WGS) at 55-65X coverage utilizing the PacBio long-read sequencing platform in SiHa and HeLa cells, followed by comprehensive analyses of the sequence data to elucidate the complexity of HPV integration. Firstly, our results demonstrated that PacBio long-read sequencing effectively identifies HPV integration breakpoints with comparable accuracy to targeted-capture Next-generation sequencing (NGS) methods. Secondly, we constructed detailed models of complex integrated genome structures that included both the HPV genome and nearby regions of the human genome by utilizing PacBio long-read WGS. Thirdly, our sequencing results revealed the occurrence of a wide variety of genome-wide structural variations (SVs) in SiHa and HeLa cells. Additionally, our analysis further revealed a potential correlation between changes in gene expression levels and SVs on chromosome 13 in the genome of SiHa cells. CONCLUSIONS: Using PacBio long-read sequencing, we have successfully constructed complex models illustrating HPV integrated genome structures in SiHa and HeLa cells. This accomplishment serves as a compelling demonstration of the valuable capabilities of long-read sequencing in detecting and characterizing HPV genomic integration structures within human cells. Furthermore, these findings offer critical insights into the complex process of HPV16 and HPV18 integration and their potential contribution to the development of cervical cancer.

Steering Electron-Induced Surface Reaction via a Molecular Assembly Approach.

Electrons not only serve as a "reactant" in redox reactions but also play a role in "catalyzing" some chemical processes. Despite the significance and ubiquitousness of electron-induced chemistry, many related scientific issues still await further exploration, among which is the impact of molecular assembly. In this work, microscopic insights into the vital role of molecular assembly in tweaking the electron-induced surface chemistry are unfolded by combined scanning tunneling microscopy and density functional theory studies. It is shown that the selective dissociation of a C-Cl bond in 4,4″-dichloro-1,1':3',1''-terphenyl (DCTP) on Cu(111) can be efficiently triggered by an electron injection via the STM tip into the unoccupied molecular orbital. The DCTP molecules are embedded in different assembly structures, including its self-assembly and coassemblies with Br adatoms. The energy threshold for the C-Cl bond cleavage increases as more Br adatoms stay close to the molecule, indicative of the sensitive response of the electron-induced surface reactivity of the C-Cl bond to the subtle change in the molecular assembly. Such a phenomenon is rationalized by the energy shift of the involved unoccupied molecular orbital of DCTP that is embedded in different assemblies. These findings shed new light on the tuning effect of molecular assembly on electron-induced reactions and introduce an efficient approach to precisely steer surface chemistry.

Architecting the Microenvironment Skeleton of Active Materials in High-Capacity Electrodes by Self-Assembled Nano-Building Blocks.

In analogy to the cell microenvironment in biology, understanding and controlling the active-material microenvironment (ME@AM) microstructures in battery electrodes is essential to the successes of energy storage devices. However, this is extremely difficult for especially high-capacity active materials (AMs) like sulfur, due to the poor controlling on the electrode microstructures. To conquer this challenge, here, a semi-dry strategy based on self-assembled nano-building blocks is reported to construct nest-like robust ME@AM skeleton in a solvent-and-stress-less way. To do that, poly(vinylidene difluoride) nanoparticle binder is coated onto carbon-nanofibers (NB@CNF) via the nanostorm technology developed in the lab, to form self-assembled nano-building blocks in the dry slurry. After compressed into an electrode prototype, the self-assembled dry-slurry is then bonded by in-situ nanobinder solvation. With this strategy, mechanically strong thick sulfur electrodes are successfully fabricated without cracking and exhibit high capacity and good C-rate performance even at a high AM loading (25.0 mg cm-2 by 90 wt% in the whole electrode). This study may not only bring a promising solution to dry manufacturing of batteries, but also uncover the ME@AM structuring mechanism with nano-binder for guiding the design and control on electrode microstructures.

Metasurface-assisted amorphous germanium-tin waveguide bolometer for mid-infrared photodetection.

An amorphous germanium-tin (a-Ge0.83Sn0.17) waveguide bolometer featuring a one-dimension (1D) metasurface absorber is proposed for mid-infrared photodetection at room-temperature. The device is based on the germanium-on-silicon (GOS) photonic platform. The impacts of the 1D metasurface on the performances of the waveguide bolometer are investigated. The responsivity of the a-Ge0.83Sn0.17 waveguide bolometer could be significantly enhanced by the metasurface. A responsivity of around -3.17%/µW within the 4.1 ∼ 4.3 µm wavelength range is achieved. In addition, a 3-dB roll-off frequency higher than 10 kHz is obtained.

Aluminum scandium nitride on 8-inch Si wafers: material characterization and photonic device demonstration.

The anisotropic optical properties of aluminum scandium nitride (Al1-xScxN) thin films for both ordinary and extraordinary light are investigated. A quantitative analysis of the band structures of the wurtzite Al1-xScxN is carried out. In addition, Al1-xScxN photonic waveguides and bends are fabricated on 8-inch Si substrates. With x = 0.087 and 0.181, the light propagation losses are 5.98 ± 0.11 dB/cm and 8.23 ± 0.39 dB/cm, and the 90° bending losses are 0.05 dB/turn and 0.08 dB/turn at 1550 nm wavelength, respectively.

Waveguide-integrated van der Waals heterostructure photodetector on a lithium niobate on insulator platform.

Lithium niobate (LN) photonics has gained significant interest for their distinct material properties. However, achieving monolithically integrated photodetectors on lithium niobate on an insulator (LNOI) platform for communication wavelengths remains a challenge due to the large bandgap and extremely low electrical conductivity of LN material. A two-dimensional (2D) material photodetector is an ideal solution for LNOI photonics with a strong light-matter interaction and simple integration technique. In this work, a van der Waals heterostructure photodiode composed of a p-type black phosphorus layer and an n-type MoS2 layer is successfully demonstrated for photodetection at communication wavelengths on a LNOI platform. The LNOI waveguide-integrated BP-MoS2 photodetector exhibits a dark current as low as 0.21 nA and an on/off ratio exceeding 200 under zero voltage bias with an incident power of 13.93 µW. A responsivity as high as 1.46 A/W is achieved at -1 V bias with a reasonable dark current around 2.33 µA. With the advantages of high responsivity, low dark current, and simple fabrication process, it is promising for the monolithically integrated photodetector application for LNOI photonic platforms at communication wavelengths.

GPS2 ameliorates cigarette smoking-induced pulmonary vascular remodeling by modulating the ras-Raf-ERK axis.

BACKGROUND: Mitogen-activated protein kinase (MAPK)signaling-mediated smoking-associated pulmonary vascular remodeling (PVR) plays an important role in the pathogenesis of group 3 pulmonary hypertension (PH). And G protein pathway suppressor 2 (GPS2) could suppress G-protein signaling such as Ras and MAPK, but its role in cigarette smoking -induced PVR (CS-PVR) is unclear. METHODS: An in vivo model of smoke-exposed rats was constructed to assess the role of GPS2 in smoking-induced PH and PVR. In vitro, the effects of GPS2 overexpression and silencing on the function of human pulmonary arterial smooth cells (HPASMCs) and the underlying mechanisms were explored. RESULTS: GPS2 expression was downregulated in rat pulmonary arteries (PAs) and HPASMCs after CS exposure. More importantly, CS-exposed rats with GPS2 overexpression had lower right ventricular systolic pressure (RVSP), right ventricular hypertrophy index (RVHI), and wall thickness (WT%) than those without. And enhanced proliferation and migration of HPASMCs induced by cigarette smoking extract (CSE) can be evidently inhibited by overexpressed GPS2. Besides, GPS2siRNA significantly enhanced the proliferation, and migration of HPASMCs as well as activated Ras and Raf/ERK signaling, while these effects were inhibited by zoledronic acid (ZOL). In addition, GPS2 promoter methylation level in rat PAs and HPASMCs was increased after CS exposure, and 5-aza-2-deoxycytidine (5-aza) inhibited CSE-induced GPS2 hypermethylation and downregulation in vitro. CONCLUSIONS: GPS2 overexpression could improve the CS-PVR, suggesting that GPS2 might serve as a novel therapeutic target for PH-COPD in the future.

Pseudomonas paeninsulae sp. nov. and Pseudomonas svalbardensis sp. nov., isolated from Antarctic intertidal sediment and Arctic soil, respectively.

Two Gram-stain-negative, aerobic, rod-shaped, non-endospore-forming and motile bacterial strains, designated IT1137T and S025T, were isolated from an intertidal sediment sample collected from the Fildes Peninsula (King George Island, Maritime Antarctica) and a soil sample under red snow in the Ny-Ålesund region (Svalbard, High Arctic), respectively. The 16S rRNA gene sequence similarity values grouped them in the genus Pseudomonas. The two strains were characterized phenotypically using API 20E, API 20NE, API ZYM and Biolog GENIII tests and chemotaxonomically by their fatty acid contents, polar lipids and respiratory quinones. Multilocus sequence analysis (concatenated 16S rRNA, gyrB, rpoB and rpoD sequences), together with genome comparisons by average nucleotide identity and digital DNA-DNA hybridization, were performed. The results showed that the similarity values of the two isolates with the type strains of related Pseudomonas species were below the recognized thresholds for species definition. Based on polyphasic taxonomy analysis, it can be concluded that strains IT1137T and S025T represent two novel species of the genus Pseudomonas, for which the names Pseudomonas paeninsulae sp. nov. (type strain IT1137T=PMCC 100533T=CCTCC AB 2023226T=JCM 36637T) and Pseudomonas svalbardensis sp. nov. (type strain S025T=PMCC 200367T= CCTCC AB 2023225T=JCM 36638T) are proposed.

Proteomic analysis of the effects of Dictyophora polysaccharide on arsenic-induced hepatotoxicity in rats.

Arsenic (As) is a highly toxic environmental toxicant and a known human carcinogen. Long-term exposure to As can cause liver injury. Dictyophora polysaccharide (DIP) is a biologically active natural compound found in the Dictyophora with excellent antioxidation, anti-inflammation, and immune protection properties. In this study, the Sprague-Dawley (SD) rat model of As toxicity was established using a feeding method, followed by DIP treatment in rats with As-induced liver injury. The molecular mechanisms of As toxicity to the rat liver and the protective effect of DIP were investigated by proteomic studies. The results showed that 172, 328 and 191 differentially expressed proteins (DEPs) were identified between the As-exposed rats versus control rats (As/Ctrl), DIP treated rats versus As-exposed rats (DIP+As/As), and DIP treated rats versus control rats (DIP+As /Ctrl), respectively. Among them, the expression of 90 DEPs in the As/Ctrl groups was reversed by DIP treatment. As exposure caused dysregulation of metabolic pathways, mitochondria, oxidative stress, and apoptosis-related proteins in the rat liver. However, DIP treatment changed or restored the levels of these proteins, which attenuated the damage to the livers of rats caused by As exposure. The results provide new insights into the mechanisms of liver injury induced by As exposure and the treatment of DIP in As poisoning.

Enhancing the Activity of a Carbon Nitride Photocatalyst by Constructing a Triazine-Heptazine Homojunction.

Establishing homojunctions at the molecular level between different but physicochemically similar phases belonging to the same family of materials is an effective approach to promoting the photocatalytic activity of polymeric carbon nitride (CN) materials. Here, we prepared a CN material with a uniform distribution of homojunctions by combining two synthetic strategies: supramolecular assemblies as the precursor and molten salt as the medium. We designed porous CN rods with triazine-heptazine homojunctions (THCNs) using a melem supramolecular aggregate (Me) and melamine as the precursors and a KCl/LiBr salt mixture as the liquid reaction medium. The triazine/heptazine ratio is controlled by varying the relative amounts of the chosen precursors, and the molten salt treatment enhances the structural order of the interplanar packing units for the THCN skeleton, leading to rapid charge migration. The resulting built-in electric field induced by the triazine-heptazine homojunction enhances photogenerated charge separation; the optimal THCN catalyst exhibits an excellent H2 evolution rate via photocatalytic water splitting, which is ∼24 times as high as that of reference bulk CN, with long-term stability.

Effectiveness of bevacizumab in the treatment of metastatic colorectal cancer: a systematic review and meta-analysis.

OBJECTIVE: To evaluate the benefit of bevacizumab under the comprehensive treatment strategy and its advantages over other drugs, so as to provide reference for the formulation of clinical plans. METHODS: As of October 1, 2022, the randomized controlled clinical trials of bevacizumab in combination with metastatic colorectal cancer published in PubMed, Cochrane Library and Medline databases were searched. The odds ratio (OR) and its 95% confidence interval (CI) were used to evaluate the short-term disease control effect and long-term survival of the treatment strategy. RESULTS: 21 RCTs (6665 patients; 3356 patients in the experimental group and 3309 patients in the control group; average age, 55-75 years) were treated with bevacizumab as the experimental group for metastatic colorectal cancer. BEV has stronger anti-tumor activity than the single treatment scheme (OR = 1.30, 95% CI: 1.11-1.52). And Benefits of the BEV group were 0.73 (0.55, 0.96), 1.26 (0.71, 2.24), 1.63 (0.92, 2.87) and 0.07 (0.02, 0.25) compared with CET, VAN, CED and PAN respectively. The disease control of BEV combined therapy was better (OR = 1.36, 95% CI: 1.04-1.78). The same as compared with cediranib (OR = 1.94, 95% CI: 1.06-3.55). However, the long-term prognosis of BEV, including the overall survival (HRs = 0.98, 95% CI: 0.84-1.15) and progression-free survival (HRs = 1.05,95% CI: 0.97-1.13) were not prolonged. The survival benefits of cetuximab and panitumumab were not reflected. CONCLUSION: The addition of BEV can enhance the anti-tumor ability and disease control, while cetuximab and panitumumab may have stronger ability. However, it did not effectively improve the survival of patients. A more reasonable and effective treatment plan needs more clinical experimental support.

Synergistic effects of selenium and zinc on Bletilla striata (Thunb.) Reichb. F. growth and polysaccharide antioxidation.

Selenium (Se) is a beneficial trace element for plants, while zinc (Zn) is a vital micronutrient. Bletilla striata (Thunb.) Reichb. F. is widely recognized as a medicinal herb. In this study, Se and Zn were introduced to determine the medicinal properties of B. striata. The plant's biomass, polysaccharides, Se and Zn contents, and the antioxidant properties of polysaccharide solutions were all examined. A notable increase in polysaccharide synthesis in B. striata tubers was observed following the application of 0.2 kg ha-1 of Se, and 1.0 kg ha-1 of Zn, either individually or in combination. Se and Zn content in polysaccharides were 3.33 to 3.77 mg kg-1 and 82.82 to 121.78 mg kg-1, at 1.0 kg ha-1 Se and 10.0 kg ha-1 Zn treatments, respectively. These values were 2.1-3.1 times and 1.8-2.8 times higher than those observed in control samples. Polysaccharide antioxidation has resulted in an increase in antioxidant activity as the concentration of polysaccharide solutions increased. The largest scavenging of 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radicals and the most excellent reducing power of the polysaccharide solutions were observed when a mixture of Se and Zn was applied at a rate of 1.0 kg ha-1 and 10.0 kg ha-1. The individual application of Se at 1.0 kg ha-1 and Zn at 10.0 kg ha-1 also resulted in significant DPPH radicals scavenging and reduced power. These data suggested that Se-Zn enriched B. striata is a new source of Se and Zn supplementation and an antioxidant resource.

Effects of arsenic exposure on blood trace element levels in rats and sex differences.

Arsenic (As) is a widespread environmental metalloid and human carcinogen, and its exposure is associated with a wide range of toxic effects, leading to serious health hazards. As poisoning is a complex systemic multi-organ and multi-system damage disease. In this study, a rat model of As poisoning was established to investigate the levels of trace elements in the blood of rats and sex differences in the effect of As on every trace elements in rat blood. Twenty 6-week-old SD (Sprague Dawley) rats were randomly divided into the control group and the As-exposed group. After 3 months, the contents of 19 elements including As in the blood were detected in these two groups by inductively coupled plasma mass spectrometry (ICP-MS). As levels in the blood of As-exposed rats were significantly higher than those in the control group, with increased levels of Rb, Sr, Cs and Ce, and decreased levels of Pd. As showed a significant positive correlation with Rb. There were significant sex differences in blood Se, Pd, Eu, Dy, Ho, and Au levels in the As-exposed group. The results showed that As exposure can lead to an increase of As content in blood and an imbalance of some elements. There were sex differences in the concentration and the correlation between elements of some elements. Elemental imbalances may affect the toxic effects of As and play a synergistic or antagonistic role in As toxicity.

Unbalanced X;Y translocations carrying SRY in prenatal settings: Clinical, molecular, and cytogenetic analysis of three cases.

BACKGROUND: Generally, the translocation of SRY onto one of the X chromosomes leads to 46, XX testicular disorders of sex development, a relatively rare condition characterized by the presence of testicular tissue with a 46, XX karyotype. Three prenatal cases of unbalanced X; Y translocation carrying SRY were identified in this study. METHODS: Structural variants were confirmed using single nucleotide polymorphism array and chromosomal karyotyping. X chromosome inactivation (XCI) was also analyzed. Detailed clinical features of the three cases were collected. RESULTS: We identified two fetuses with maternal inherited unbalanced X; Y translocations carrying SRY and skewed XCI presenting with normal female external genitalia, and one fetus with de novo 46, XX (SRY+) and random XCI manifested male phenotypic external genitalia. CONCLUSION: This study reports that cases with unbalanced X; Y translocations carrying SRY manifested a normal female external genitalia in a prenatal setting. We speculate that the skewed XCI mediates the silence of SRY. In addition, our study emphasizes that combining clinical findings with pedigree analysis is critical for estimating the prognosis of fetuses with sex chromosome abnormalities.

Asian Screening Array and Next-Generation Sequencing Based Panels Applied to Preimplantation Genetic Testing for Monogenic Disorders Preclinical Workup in 294 Families: A Retrospective Analysis.

OBJECTIVE: Currently, the most commonly used methods for linkage analysis of pre-implantation genetic testing for monogenic disorders (PGT-M) are next generation sequencing (NGS) and SNP array. We aim to investigate whether the application efficacy of Asian screening array (ASA) in PGT-M preclinical workup for the Chinese population is superior to NGS based single nucleotide polymorphism (SNP) panels. METHODS: We conducted a retrospective analysis by reviewing 294 couples from a single center over the past 4 years and compared the detection results between NGS-based SNP panels and ASA. Using the numbers of informative SNPs upstream and downstream flanking of variants, we assessed the detection efficiency of both methods in monogenic diseases, chromosomal microdeletion syndrome and males with de novo variants, among other scenarios. RESULTS: Results indicate that ASA offers a greater number of informative SNPs compared with NGS-based SNP panels. Additionally, data analysis for ASA is generally more straightforward and may require less computational resources. While ASA can address most PGT-M challenges, we have also identified certain genes in previous tests that are not suitable for PGT-M using ASA. CONCLUSION: The application of ASA in PGT-M preclinical workup for Chinese populations has good practical value as it can perform linkage analysis for most genetic variants. However, for certain variants, NGS or other testing methods, such as mutated allele revealed by sequencing with aneuploidy and linkage analysis (MARSALA), may still be necessary for completion.

Status of Professional Identity, Self-Directed Learning Competence, and Self-Efficacy Among Central Sterile Supply Department Nurses.

BACKGROUND Previous studies on professional identity, self-directed learning competence, and self-efficacy among central sterile supply department (CSSD) nurses are rare. We investigated the status of these 3 characteristics among CSSD nurses and offered suggestions, to provide a reference for CSSD talent development. MATERIAL AND METHODS CSSD nurses working in 45 hospitals in southwest China were invited to participate in a questionnaire survey in August 2021. The survey comprised a general information questionnaire, a self-directed learning competence rating scale, a professional identity scale, and a general self-efficacy scale. RESULTS The CSSD nurses' scores for professional identity, self-directed learning competence, and self-efficacy were 109.92±17.161, 125.77±21.316, and 26.92±6.633, respectively. For professional identity, statistically significant differences were identified (P≤0.05) for 3 factors: monthly income, reason for studying nursing, and reason for working in the CSSD. For self-directed learning competence, statistically significant differences (P≤0.05) were identified for 5 factors: age, hospital grade, type of employee, monthly income, and reason for working in the CSSD. For self-efficacy, statistically significant differences were identified (P≤0.05) for 3 factors: age, reason for studying nursing and working in the CSSD, and whether the CSSD nurses wished their children to become nurses. CONCLUSIONS The professional identity, self-directed learning competence, and self-efficacy of the CSSD nurses in this study were at the medium level. More attention should be paid to career planning of young nurses and improvement of their professional identity and self-directed learning competence.

Non-uniform distributed silicon optical phased array for high directionality and a wide steering range.

A non-uniform distributed silicon optical phased array (OPA) is proposed and numerically demonstrated to realize high directionality and a wide range for beam steering. The OPA is composed of grating antennas with dual-layer corrugations along silicon strip waveguides, which can achieve a high directionality of 0.96 and a small divergence angle of 0.084°. To reduce the crosstalk between adjacent antennas and realize a wide steering range, the genetic algorithm is improved and utilized to arrange the locations of grating antennas. As a proof of concept, a 32-channel non-uniform distributed OPA is designed and thoroughly optimized. The simulation results successfully demonstrate a two-dimensional wide steering range of 70∘×18.7∘ with a side-mode suppression ratio (SMSR) over 10 dB.

All-silicon metalens for broadband achromatic polarization multiplexing in long-wave infrared wavelengths.

Traditional long-wave infrared polarimetry usually relies on complex optical setups, making it challenging to meet the increasing demand for system miniaturization. To address this problem, we design an all-silicon broadband achromatic polarization-multiplexing metalens (BAPM) operating at the wavelength range of 9-12 µm. A machine-learning-based design method is developed to replace the tedious and computationally intensive simulation of a large number of meta-atoms. The results indicate that the coefficients of variation in focal length of the BAPM are 3.95% and 3.71%, and the average focusing efficiencies are 41.3% and 40.5% under broadband light incidence with x- and y-polarizations, respectively.

Factors associated with damages and repair costs of reusable flexible bronchoscopes in pediatrics in China.

BACKGROUND: Frequent repairs of pediatric flexible bronchoscopes can lead to a huge financial burden for the hospital. This study aimed to investigate the common causes of the failures in pediatric flexible bronchoscopes and propose the measures to prevent the failures. METHODS: This was a retrospective study. We collected repair information of the pediatric flexible bronchoscopes reprocessed in the Department of Sterile Processing at a hospital between September 1, 2018 and September 1, 2022 in order to investigate the causes and possible factors associated with the failures in pediatric flexible bronchoscopes. RESULTS: The Department of Sterile Processing staff reprocessed the pediatric flexible bronchoscopes 4280 times. A total of 29 failures were identified. The failure rate was 0.678%. The average repair cost was USD7246.60. The common failures in the pediatric flexible bronchoscopes included dim video image, black dots, improper video image display or no image during angulation adjustment, and pressure marks in the insertion tube. The failure rates in flexible electronic bronchoscopes and small-diameter flexible bronchoscopes were 65.5% and 93.1%, respectively. The failure rate in the pediatric flexible bronchoscopes reprocessed by the staff members with less work experience was 75.9%. CONCLUSION: The failure rate in the pediatric flexible bronchoscopes was not high but the repair costs were extremely high. The types and size of the flexible bronchoscopes and work experience of the staff members responsible for bronchoscope reprocessing were the possible factors associated with the failure rate in the pediatric flexible bronchoscopes. It is advisable to further optimize the central workflow and management mode for reprocessing the pediatric flexible bronchoscopes, thereby extending their useful life and reducing costs.