Structural basis of closed groove scrambling by a TMEM16 protein.

Activation of Ca2+-dependent TMEM16 scramblases induces phosphatidylserine externalization, a key step in multiple signaling processes. Current models suggest that the TMEM16s scramble lipids by deforming the membrane near a hydrophilic groove and that Ca2+ dependence arises from the different association of lipids with an open or closed groove. However, the molecular rearrangements underlying groove opening and how lipids reorganize outside the closed groove remain unknown. Here we directly visualize how lipids associate at the closed groove of Ca2+-bound fungal nhTMEM16 in nanodiscs using cryo-EM. Functional experiments pinpoint lipid-protein interaction sites critical for closed groove scrambling. Structural and functional analyses suggest groove opening entails the sequential appearance of two π-helical turns in the groove-lining TM6 helix and identify critical rearrangements. Finally, we show that the choice of scaffold protein and lipids affects the conformations of nhTMEM16 and their distribution, highlighting a key role of these factors in cryo-EM structure determination.

Modified Nishida muscle transposition procedure combined with superior rectus muscle tenotomy for inferior rectus muscle aplasia.

The modified Nishida muscle transposition procedure, in which one-third of each vertical rectus muscle belly is sutured onto the sclera in the infero- and superotemporal quadrants without either tenotomy of the vertical rectus muscles or splitting of the vertical rectus muscle is an effective treatment for abducens nerve palsy. We report a case of inferior rectus muscle aplasia treated using the modified Nishida procedure to transpose both horizontal rectus muscles inferiorly combined with superior rectus tenotomy.

Probiotics' effects on gut microbiota in jaundiced neonates: a randomized controlled trial protocol.

Introduction: Recent evidence suggests that blue-light phototherapy impacts gut microbiota composition in jaundiced newborns, leading to disturbances closely related to the therapy's side effects. As a result, gut microbiota may serve as a potential intervention target to mitigate these side effects. In this study, we aim to examine the effects of AB-GG (Lactobacillus rhamnosus LGG), Bb-12 (Bifidobacterium animalis Bb-12) and M-16V (Bifidobacterium breve M-16V) and their combination on the intestinal microbiota, metabolomics and phototherapy-related side effects in neonates with jaundice. Methods and analysis: A total of 100 jaundiced newborns aged two weeks or younger will be included in this randomized, single-blind (the parents knew, but the neonatologists did not know), single-center controlled trial to receive either 109 colony-forming units of AB-GG, Bb-12, M-16V, a combination of the three probiotics with blue-light phototherapy, or blue-light phototherapy alone. The experimental group will be treated with oral probiotics once daily for 30 days, while the control group will receive only blue-light phototherapy. The follow-up duration will last 30 days. The primary outcomes include changes in gut microbiota, metabolomics, and the incidence of phototherapy side effects, assessed after each phototherapy session, as well as on days 10, 20, and 30. Ethics and dissemination: The study protocol has been approved by the Ethics Committee of our institution. The findings of this trial will be submitted to a peer-reviewed pediatric journal. Its abstracts will be submitted to relevant national and international conferences. Clinical Trial Registration: http://www.chictr.org.cn/index.aspx, identifer (ChiCTR2000036013).

Advances in disilylation reactions to access cis/trans-1,2-disilylated and gem-disilylated alkenes.

Organosilane compounds are widely used in both organic synthesis and materials science. Particularly, 1,2-disilylated and gem-disilylated alkenes, characterized by a carbon-carbon double bond and multiple silyl groups, exhibit significant potential for subsequently diverse transformations. The versatility of these compounds renders them highly promising for applications in materials, enabling them to be valuable and versatile building blocks in organic synthesis. This review provides a comprehensive summary of methods for the preparation of cis/trans-1,2-disilylated and gem-disilylated alkenes. Despite notable advancements in this field, certain limitations persist, including challenges related to regioselectivity in the incorporation and chemoselectivity in the transformation of two nearly identical silyl groups. The primary objective of this review is to outline synthetic methodologies for the generation of these alkenes through disilylation reactions, employing silicon reagents, specifically disilanes, hydrosilanes, and silylborane reagents. The review places particular emphasis on investigating the practical applications of the C-Si bond of disilylalkenes and delves into an in-depth discussion of reaction mechanisms, particularly those reactions involving the activation of Si-Si, Si-H, and Si-B bonds, as well as the C-Si bond formation.

Interfacial Polarization Locked Flexible ß-Phase Glycine/Nb2 CTx Piezoelectric Nanofibers.

Biomolecular piezoelectric materials show great potential in the field of wearable and implantable biomedical devices. Here, a self-assemble approach is developed to fabricating flexible ß-glycine piezoelectric nanofibers with interfacial polarization locked aligned crystal domains induced by Nb2 CTx nanosheets. Acted as an effective nucleating agent, Nb2 CTx nanosheets can induce glycine to crystallize from edges toward flat surfaces on its 2D crystal plane and form a distinctive eutectic structure within the nanoconfined space. The interfacial polarization locking formed between O atom on glycine and Nb atom on Nb2 CTx is essential to align the ß-glycine crystal domains with (001) crystal plane intensity extremely improved. This ß-phase glycine/Nb2 CTx nanofibers (Gly-Nb2 C-NFs) exhibit fabulous mechanical flexibility with Young's modulus of 10 MPa, and an enhanced piezoelectric coefficient of 5.0 pC N-1 or piezoelectric voltage coefficient of 129 × 10-3 Vm N-1 . The interface polarization locking greatly improves the thermostability of ß-glycine before melting (≈210°C). A piezoelectric sensor based on this Gly-Nb2 C-NFs is used for micro-vibration sensing in vivo in mice and exhibits excellent sensing ability. This strategy provides an effective approach for the regular crystallization modulation for glycine crystals, opening a new avenue toward the design of piezoelectric biomolecular materials induced by 2D materials.

Protocol for iron-catalyzed cross-electrophile coupling of aryl chlorides with unactivated alkyl chlorides.

Organochlorides are a crucial class of electrophiles in organic synthesis. Here, we present a protocol for the cross-electrophile coupling of aryl chlorides with unactivated alkyl chlorides, facilitated by an iron/B2pin2 catalytic system. We describe steps for the coupling of aryl chlorides with alkyl chlorides, followed by purification of products. This protocol can produce alkylated products with up to 81% yield. For complete details on the use and execution of this protocol, please refer to Zhang et al.1.

Structural basis of closed groove scrambling by a TMEM16 protein.

Activation of Ca2+-dependent TMEM16 scramblases induces the externalization of phosphatidylserine, a key molecule in multiple signaling processes. Current models suggest that the TMEM16s scramble lipids by deforming the membrane near a hydrophilic groove, and that Ca2+ dependence arises from the different association of lipids with an open or closed groove. However, the molecular rearrangements involved in groove opening and of how lipids reorganize outside the closed groove remain unknown. Using cryogenic electron microscopy, we directly visualize how lipids associate at the closed groove of Ca2+-bound nhTMEM16 in nanodiscs. Functional experiments pinpoint the lipid-protein interaction sites critical for closed groove scrambling. Structural and functional analyses suggest groove opening entails the sequential appearance of two π-helical turns in the groove-lining TM6 helix and identify critical rearrangements. Finally, we show that the choice of scaffold protein and lipids affects the conformations of nhTMEM16 and their distribution, highlighting a key role of these factors in cryoEM structure determination.

Exosome Derived from Mesenchymal Stem Cells Alleviates Hypertrophic Scar by Inhibiting the Fibroblasts via TNFSF-13/HSPG2 Signaling Pathway.

Background: Mesenchymal stem cell-derived exosomes (MSC-exo) have been shown to have significant potential in wound healing and scar relief processes. According to reports, TNFSF13 and HSPG2 are associated with various fibrotic diseases. The aim of this study is to investigate how TNFSF13 and HSPG2 affect the formation of hypertrophic scar (HS) and the mechanism by which exosomes regulate HS. Methods: Immunohistochemistry, qRT-PCR, Western blot, and immunofluorescence were performed to measure TNFSF13 expression in HS skin tissues and hypertrophic scar fibroblast (HSF). HSF were treated with recombinant TNFSF13 protein and TNFSF13 siRNAs to probe the effect of TNFSF13 on the activity of HSF. The CCK-8, EdU, Transwell, and Western blot were used to investigate the role of TNFSF13 in viability, proliferation and inflammation. The influence of MSC-exo on the proliferation and function of HSF was determined by scratch and Western blot. Results: TNFSF13 was dramatically up-regulated in HS skin tissues and HSF. Recombinant TNFSF13 protein increased cell viability, proliferation, migration, fibrosis, inflammation, and the binding between TNFSF13 and HSPG2 of HSF. The opposite results were obtained in TNFSF13 siRNAs transferred HSF. Furthermore, TNFSF13 activated the nuclear factor-κB (NF-κB) signaling pathway. Silencing of HSPG2 and inhibition of NF-κB remarkably eliminated the promoting effects of TNFSF13 on cell viability, proliferation, migration, fibrosis and inflammation of HSF. MSC-exo reduced α-SMA and COL1A1 inhibited the proliferation and migration of HSF by inhibiting TNFSF13 and HSPG2. Conclusion: TNFSF13 activates NF-κB signaling pathway by interacting with HSPG2, which regulates the proliferation, migration, fibrosis and inflammatory response of HSF. Through the above mechanisms, knocking out TNFSF13 can inhibit the proliferation, migration, fibrosis and inflammatory response of HSF, whereas MSC-exo could reverse this process. These results suggest that MSC-exo alleviates HS by inhibiting the fibroblasts via TNFSF-13/HSPG2 signaling pathway.

Soft ferroelectret ultrasound receiver for targeted peripheral neuromodulation.

Bioelectronic medicine is a rapidly growing field where targeted electrical signals can act as an adjunct or alternative to drugs to treat neurological disorders and diseases via stimulating the peripheral nervous system on demand. However, current existing strategies are limited by external battery requirements, and the injury and inflammation caused by the mechanical mismatch between rigid electrodes and soft nerves. Here we report a wireless, leadless, and battery-free ferroelectret implant, termed NeuroRing, that wraps around the target peripheral nerve and demonstrates high mechanical conformability to dynamic motion nerve tissue. As-fabricated NeuroRing can act as an ultrasound receiver that converts ultrasound vibrations into electrostimulation pulses, thus stimulating the targeted peripheral nerve on demand. This capability is demonstrated by the precise modulation of the sacral splanchnic nerve to treat colitis, providing a framework for future bioelectronic medicines that offer an alternative to non-specific pharmacological approaches.

Structural basis of closed groove scrambling by a TMEM16 protein.

Activation of Ca2+-dependent TMEM16 scramblases induces the externalization of phosphatidylserine, a key molecule in multiple signaling processes. Current models suggest that the TMEM16s scramble lipids by deforming the membrane near a hydrophilic groove, and that Ca2+ dependence arises from the different association of lipids with an open or closed groove. However, the molecular rearrangements involved in groove opening and of how lipids reorganize outside the closed groove remain unknown. Using cryogenic electron microscopy, we directly visualize how lipids associate at the closed groove of Ca2+-bound nhTMEM16 in nanodiscs. Functional experiments pinpoint the lipid-protein interaction sites critical for closed groove scrambling. Structural and functional analyses suggest groove opening entails the sequential appearance of two π-helical turns in the groove-lining TM6 helix and identify critical rearrangements. Finally, we show that the choice of scaffold protein and lipids affects the conformations of nhTMEM16 and their distribution, highlighting a key role of these factors in cryoEM structure determination.

Kawasaki disease with peritonsillar abscess as the first symptom: A case report.

BACKGROUND: Kawasaki disease (KD), also known as mucocutaneous lymph node syndrome, is an acute, self-limiting vasculitis of unknown aetiology that mainly involves the medium and small arteries and can lead to serious cardiovascular complications, with a 25% incidence of coronary artery aneurysms. Periton-Sillar abscesses are a rare symptom of KD and is easily misdiagnosed at its early stages. CASE SUMMARY: A 5-year-old boy who presented to a community hospital with a 3-d fever, difficulty in opening his mouth, and neck pain and was originally treated for throat infection without improvement. On the basis of laboratory tests, ultrasound of submandibular and superficial lymph nodes and computed tomography of the neck, the clinician diagnosed the periamygdala abscess and sepsis that did not resolve after antibiotic therapy. On the fifth day of admission, the child developed conjunctival congestion, prune tongue, perianal congestion and desquamation, and slightly stiff and swollen bunions on both feet. A diagnosis of KD was reached with complete remission after intravenous immunoglobulin treatment. CONCLUSION: Children with neck pain, lymph node enlargement, or airway obstruction as the main manifestations are poorly treated with intravenous broad-spectrum antibiotics. Clinicians should not rush invasive operations such as neck puncture, incision, and drainage and should be alert for KD when it cannot be explained by deep neck space infection and early treatment with aspirin combined with gammaglobulin.

Surface Functional Modification by Ti3 C2 Tx MXene on PLLA Nanofibers for Optimizing Neural Stem Cell Engineering.

Optimizing cell substrates by surface modification of neural stem cells (NSCs), for efficient and oriented neurogenesis, represents a promising strategy for treating neurological diseases. However, developing substrates with the advanced surface functionality, conductivity, and biocompatibility required for practical application is still challenging. Here, Ti3 C2 Tx MXene is introduced as a coating nanomaterial for aligned poly(l-lactide) (PLLA) nanofibers (M-ANF) to enhance NSC neurogenesis and simultaneously tailor the cell growth direction. Ti3 C2 Tx MXene treatment provides a superior conductivity substrate with a surface rich in functional groups, hydrophilicity, and roughness, which can provide biochemical and physical cues to support NSC adhesion and proliferation. Moreover, Ti3 C2 Tx MXene coating significantly promotes NSC differentiation into both neurons and astrocytes. Interestingly, Ti3 C2 Tx MXene acts synergistically with the alignment of nanofibers to promote the growth of neurites, indicating enhanced maturation of these neurons. RNA sequencing analysis further reveals the molecular mechanism by which Ti3 C2 Tx MXene modulates the fate of NSCs. Notably, surface modification by Ti3 C2 Tx MXene mitigates the in vivo foreign body response to implanted PLLA nanofibers. This study confirms that Ti3 C2 Tx MXene provides multiple advantages for decorating the aligned PLLA nanofibers to cooperatively improve neural regeneration.

Thioethers as Dichotomous Electrophiles for Site-Selective Silylation via C-S Bond Cleavage.

The development of aryl alkyl sulfides as dichotomous electrophiles for site-selective silylation via C-S bond cleavage has been achieved. Iron-catalyzed selective cleavage of C(aryl)-S bonds can occur in the presence of ß-diketimine ligands, and the cleavage of C(alkyl)-S bonds can be achieved by t-BuONa without the use of transition metals, resulting in the corresponding silylated products in moderate to excellent yields. Mechanistic studies suggest that Fe-Si species may undergo metathesis reactions during the cleavage of C(aryl)-S bonds, while silyl radicals are involved during the cleavage of C(alkyl)-S bonds.

ATP2B1-AS1 exacerbates sepsis-induced cell apoptosis and inflammation by regulating miR-23a-3p/TLR4 axis

Background: Sepsis is a life-threatening disease with dominant mortality. Its early diagnosis and treatment can improve prognosis and reduce mortality. Long noncoding RNAs (lncRNAs) ATPase plasma membrane Ca2+ transporting 1 antisense RNA 1 (ATP2B1-AS1) is dysregulated and is involved in the progression of various diseases. Nevertheless, the role of ATP2B1-AS1 in sepsis remains unclear. Methods: A human monocytic cell line, THP-1 cells, was stimulated to induce a model of sepsis in vitro. The levels of ATP2B1-AS1, miR-23a-3p, and TLR4 were assessed by real-time quantitative polymerase chain reaction. The role of ATP2B1-AS1 in cell apoptosis and inflammation was explored by flow cytometry, Western blot analysis and enzyme-linked immunosorbent serologic assay. The binding sites between ATP2B1-AS1 and miR-23a-3p, and between miR-23a-3p and TLR4 were predicted by BiBiServ and the Encyclopedia of RNA Interactomes (ENCORI) online sites, respectively, and confirmed by the luciferase assay. Results: The level of ATP2B1-AS1 was increased in lipopolysaccharide (LPS)-treated THP-1 cells. LPS increased apoptosis ratio, relative protein expressions of pro-apoptotic factors, and relative messenger RNA (mRNA) level and concentrations of pro-inflammatory cytokines, but decreased the relative expression of anti-apoptosis protein and relative mRNA level and concentrations of anti-inflammatory factor. All these alterations were reversed with transfection of shATP2B1-AS1 into THP-1 cells. Moreover, ATP2B1-AS1 directly bound miR-23a-3p and negatively modulated the level of miR-23a-3p. Meanwhile, TLR4 was directly targeted by miR-23a-3p, and negatively and positively modulated by miR-23a-3p and ATP2B1-AS1, respectively. Conclusion: ATP2B1-AS1 aggravated apoptosis and inflammation by modulating miR-23a-3p/TLR4 axis in LPS-treated THP-1 cells (AU)

Recent advances in the synthesis of fluorinated amino acids and peptides.

The site-selective modification of amino acids, peptides, and proteins has always been an intensive topic in organic synthesis, medicinal chemistry, and chemical biology due to the vital role of amino acids in life. Among the developed methods, the site-selective introduction of fluorine functionalities into amino acids and peptides has emerged as a useful approach to change their physicochemical and biological properties. With the increasing demand for life science, the direct fluorination/fluoroalkylation of proteins has also received increasing attention because of the unique properties of fluorine atom(s) that can change the protein structure, increase their lipophilicity, and enable fluorine functionality as a biological tracer or probe for chemical biology studies. In this feature article, we summarized the recent advances in the synthesis of fluorinated amino acids and peptides, wherein two strategies have been discussed. One is based on the fluorinated building blocks to prepare fluorinated amino acids and peptides with diversified structures, including the transformations of fluorinated imines and nickel-catalyzed dicarbofunctionalization of alkenes with bromodifluoroacetate and its derivatives; the other is direct fluorination/fluoroakylation of amino acids, peptides, and proteins, in which the selective transformations of the functional groups on serine, threonine, tyrosine, tryptophan, and cysteine lead to a wide range of fluorinated α-amino acids, peptides, and proteins, featuring synthetic convenience and late-stage modification of biomacromolecules. These two strategies complement each other, wherein transition-metal catalysis and new fluoroalkylating reagents provide powerful tools to selectively access fluorinated amino acids, peptides, and proteins, showing the prospect of medicinal chemistry and chemical biology.

Nile tilapia DNA sensor STING is involved in the IFN-ß and AP-1 signaling pathways in the immune response dependent on DDX41.

Stimulator of interferon genes (STING) plays important roles in innate immunology. In this study, we isolated the STING gene in Nile tilapia, termed OnSTING. Using quantitative RT-PCR, we explored the expression patterns of the OnSTING gene. Using dual-luciferase reporter assays, we revealed the effect of STING overexpression on nuclear factor κB (NF-κB), IFN and AP activation in HEK 293 cells. Using coimmunoprecipitation, the interaction of STING and TRIF was studied. The effect of OnSTING overexpression on the antibacterial activity in tilapia was investigated. The results showed that upon stimulation with Streptococcus agalactiae, the OnSTING transcript was upregulated in all the tested tissues. OnSTING mRNA levels were very stable from 2.5 to 8.5 dpf. Moreover, OnSTING, OnIFN and IRF3 expression was induced by LPS, Poly (I:C), S. agalactiae WC1535 and DCPS in Nile tilapia macrophages. Overexpression of OnSTING and OnDDX41 increased NF-κB activation in HEK293T cells and slightly increased IFN-ß activation but had no effect on AP-1 activation. OnSTING interacted with OnDDX41 and OnTBK1. However, OnSTING did not interact with TRIF. OnSTING overexpression in vivo decreased the sensitivity of tilapia to S. agalactiae infection. These results are helpful for clarifying the innate immune response against bacterial infection in Nile tilapia.

Thoracoscopic laparoscopy-assisted Ivor-Lewis resection of esophagogastric junction cancer / 中华肿瘤杂志

Objective: To investigate the outcome of patients with esophagogastric junction cancer undergoing thoracoscopic laparoscopy-assisted Ivor-Lewis resection. Methods: Eighty-four patients who were diagnosed with esophagogastric junction cancer and underwent Ivor-Lewis resection assisted by thoracoscopic laparoscopy at the National Cancer Center from October 2019 to April 2022 were collected. The neoadjuvant treatment mode, surgical safety and clinicopathological characteristics were analyzed. Results: Siewert type Ⅱ (92.8%) and adenocarcinoma (95.2%) were predominant in the cases. A total of 2 774 lymph nodes were dissected in 84 patients. The average number was 33 per case, and the median was 31. Lymph node metastasis was found in 45 patients, and the lymph node metastasis rate was 53.6% (45/84). The total number of lymph node metastasis was 294, and the degree of lymph node metastasis was 10.6%(294/2 774). Among them, abdominal lymph nodes (100%, 45/45) were more likely to metastasize than thoracic lymph nodes (13.3%, 6/45). Sixty-eight patients received neoadjuvant therapy before surgery, and nine patients achieved pathological complete remission (pCR) (13.2%, 9/68). Eighty-three patients had negative surgical margins and underwent R0 resection (98.8%, 83/84). One patient, the intraoperative frozen pathology suggested resection margin was negative, while vascular tumor thrombus was seen on the postoperative pathological margin, R1 resection was performed (1.2%, 1/84). The average operation time of the 84 patients was 234.5 (199.3, 275.0) minutes, and the intraoperative blood loss was 90 (80, 100) ml. One case of intraoperative blood transfusion, one case of postoperative transfer to ICU ward, two cases of postoperative anastomotic leakage, one case of pleural effusion requiring catheter drainage, one case of small intestinal hernia with 12mm poke hole, no postoperative intestinal obstruction, chyle leakage and other complications were observed. The number of deaths within 30 days after surgery was 0. Number of lymph nodes dissection, operation duration, and intraoperative blood loss were not related to whether neoadjuvant therapy was performed (P>0.05). Preoperative neoadjuvant chemotherapy combined with radiotherapy or immunotherapy was not related to whether postoperative pathology achieved pCR (P>0.05). Conclusion: Laparoscopic-assisted Ivor-Lewis surgery for esophagogastric junction cancer has a low incidence of intraoperative and postoperative complications, high safety, wide range of lymph node dissection, and sufficient margin length, which is worthy of clinical promotion.

Visual analysis of clinical comprehensive evaluation of drugs in China by bibliometric analysis / 药学实践杂志

Objective To analyze the research status and predict the development trend of clinical comprehensive evaluation of drugs in China, and to provide reference for clinical comprehensive evaluation. Methods CNKI, Wanfang and VIP database were used to search the published articles of clinical comprehensive evaluation. Literature searching was set from the building time of the database to 2022, the basic information about the published articles was obtained for the evaluation of the literature quality. Bibliometrics and CiteSpace 6.1.R3 software were used to visualize the research authors, research institutions, and key words. Results After data screening, a total of 126 Chinese published articles were selected. The analysis showed that the numbers of published articles were rising continuously, and China Academy of Chinese Medical Sciences and Xie Yanming were the institute and the author with the maximum number of literatures, respectively. Conclusion The clinical comprehensive evaluation of drugs was conducted based on the clinical value of drugs, guided by the policy requirements. It is suggested that researchers should conduct the comprehensive evaluation according to the focus and requirements of government agencies, the pharmaceutical industry and the clinical applications.

Identification of Human Body Fluid Stains and Non-Biological Stains by Three-Dimensional Fluorescence Spectroscopy / 法医学杂志

OBJECTIVES@#To establish a rapid and nondestructive identification method for human body fluid stains and non-biological stains using three-dimensional fluorescence spectroscopy.@*METHODS@#The collected three-dimensional fluorescence spectrum data of human saliva, 3% blood, coffee and Fanta® stains were processed with dimensionality reduction. After wavelet transform, spectral denoising and feature extraction, the classification formula was established. The Fisher discriminant was used for spectrum matching and recognition to establish the analysis method to distinguish stain types.@*RESULTS@#According to the results of data training and comparison, all the recognition accuracies of Fanta®, coffee, saliva and blood were more than 91.39%. Among them, saliva reached 100% recognition accuracy.@*CONCLUSIONS@#Three-dimensional fluorescence spectroscopy is a potential method for rapid and nondestructive identification of biological and non-biological stains.

The impact of image quality on the diagnostic performance of CT-derived fractional flow reserve / 中华放射学杂志

Objective:To explore the impact of coronary CT angiography (CCTA) image quality and related factors on the diagnostic performance of CT-derived fractional flow reserve (CT-FFR).Methods:Based on the CT-FFR CHINA trial, the prospective multicenter trial enrolled patients with suspected coronary artery disease who underwent CCTA, CT-FFR and FFR measurement. The subjective and objective assessments of CCTA image were performed on a per-vessel level. The objective assessments included the enhancement degree of coronary artery, the signal-to-noise ratio (SNR) of the aortic root. We used χ 2 test and DeLong test to compare the diagnostic performance of CT-FFR with FFR as the reference standard in different subjective groups (non-artifact vs. artifact), enhancement degree of coronary artery groups (≤400 vs. 401-500 vs.>500 HU), SNR of the aortic root groups (≤16.9 vs.>16.9), body mass index (BMI) groups (<25 kg/m 2 vs.≥25 kg/m 2) and heart rate groups (<75 bpm vs.≥75 bpm). FFR and CT-FFR values≤0.80 was identified as myocardial ischemia. Results:The study enrolled 317 patients with 366 vessels. All target vessels in CCTA images were successfully analyzed by CT-FFR. The accuracy, sensitivity, specificity, positive predictive value, negative predictive value and AUC of the non-artifact group were 90.45%, 86.75%, 93.10%, 90.00%, 90.76% and 0.928, respectively, and those of the artifact group were 83.23%, 87.21%, 79.01%, 81.52%, 85.33% and 0.869, respectively. The differences in accuracy and specificity were statistically significant (χ 2=4.23, P=0.040; χ 2=8.55, P=0.003). The diagnostic efficacy of CT-FFR had no statistically significant differences among different objective groups (all P>0.05). Conclusions:The artifact of CCTA image has an effect on CT-FFR in the diagnosis of myocardial ischemia. The degree of vascular enhancement, SNR, BMI, and heart rate have no significant effect on the diagnostic performance of CT-FFR.