Microstructure and Mechanical Properties of Refill Friction Stir Spot-Welded Joints of 2A12Al and 7B04Al: Effects of Tool Size and Welding Parameters.

To solve problems in dissimilarly light metal joints, refilled friction stir spot welding (RFSSW) is proposed instead of resistance spot welding. However, rotation speed, dwell time, plunge depth, and the diameter of welding tools all have a great influence on joints, which brings great challenges in optimizing welding parameters to ensure their mechanical properties. In this study, the 1.5 mm thick 2A12Al and 2 mm thick 7B04Al lap joints were prepared by Taguchi orthogonal experiment design and RFSSW. The welding tool (shoulder) diameters were 5 mm and 7 mm, respectively. The macro/microstructures of the cross-section, the geometrical characteristics of the effective welding depth (EWD), the stir zone area (SZA), and the stir zone volume (SZV) were characterized. The shear strength and failure mode of the lap joint were analyzed using an optical microscope. It was found that EWD, SZA, and SZV had a good correlation with tensile-shear force. The optimal welding parameters of 5 mm diameter joints are 1500 rpm of rotation speed, 2.5 mm of plunge depth, and 0 s of dwell time, which for 7 mm joints are 1200 rpm, 1.5 mm, and 2 s. The tensile-shear force of 5 mm and 7 mm joints welded with these optical parameters was 4965 N and 5920 N, respectively. At the same time, the 5 mm diameter joints had better strength and strength stability.

Genomic surveillance indicates clonal replacement of hypervirulent Klebsiella pneumoniae ST881 and ST29 lineage strains in vivo.

The emergence of hypervirulent Klebsiella pneumoniae (hvKp) poses a significant public health threat, particularly regarding its carriage in the healthy population. However, the genomic epidemiological characteristics and population dynamics of hvKp within a single patient across distinct infection episodes remain largely unknown. This study aimed to investigate the clonal replacement of hvKp K2-ST881 and K54-ST29 lineage strains in a single patient experiencing multiple-site infections during two independent episodes. Two strains, designated EDhvKp-1 and EDhvKp-2, were obtained from blood and cerebrospinal fluid during the first admission, and the strain isolated from blood on the second admission was named EDhvKp-3. Whole-genome sequencing, utilizing both short-read Illumina and long-read Oxford Nanopore platforms, was conducted. In silico multilocus sequence typing (MLST), identification of antimicrobial resistance and virulence genes, and the phylogenetic relationship between our strains and other K. pneumoniae ST881 and ST29 genomes retrieved from the public database were performed. Virulence potentials were assessed through a mouse lethality assay. Our study indicated that the strains were highly susceptible to multiple antimicrobial agents. Plasmid sequence analysis confirmed that both virulence plasmids, pEDhvKp-1 (166,008 bp) and pEDhvKp-3 (210,948 bp), belonged to IncFIB type. Multiple virulence genes, including rmpA, rmpA2, rmpC, rmpD, iroBCDN, iucABCD, and iutA, were identified. EDhvKp-1 and EDhvKp-2 showed the closest relationship to strain 502 (differing by 51 SNPs), while EDhvKp-3 exhibited 69 SNPs differences compared to strain TAKPN-1, which all recovered from Chinese patients in 2020. In the mouse infection experiment, both ST881 EDhvKp-1 and ST29 EDhvKp-3 displayed similar virulence traits, causing 90 and 100% of the mice to die within 72 h after intraperitoneal infection, respectively. Our study expands the spectrum of hvKp lineages and highlights genomic alterations associated with clonal switching between two distinct lineages of hvKP that successively replaced each other in vivo. The development of novel strategies for the surveillance, diagnosis, and treatment of high-risk hvKp is urgently needed.

Anti-Inflammatory Lindenane Sesquiterpenoid Dimers from the Roots of Sarcandra glabra.

Sarglaroids A-H (1-8), eight new lindenane dimers, and a monomer sarglaroid I (9), along with fourteen known analogues (10-23), were isolated from the roots of Sarcandra glabra. The planar structures and the absolute configurations were elucidated by HR-MS, NMR, ECD calculations, and X-ray diffraction crystallography. Sarglaroid A (1) was identified as a rare 8,9-seco lindenane dimer with a unique 5/5/5 tricyclic system. The biological evaluation showed that compounds 1 and 13 potently inhibited NO production with IC50 values at 19.8 ± 1.06 and 10.7 ± 0.25 µM, respectively, and had no cytotoxicity to RAW264.7 cells. Compound 6 significantly inhibited the LPS-/ATP-induced IL-1ß release by inactivating the NLRP3 inflammasome through inhibiting the initiation and assembly by affecting the K+ efflux. Compounds 2 and 3 inhibited the proliferation of MCF-7 and MDA-MB-231 with IC50 values ranging from 5.4 to 10.2 µM.

N6-methyladenosine hypomethylation of circGPATCH2L regulates DNA damage and apoptosis through TRIM28 in intervertebral disc degeneration.

Circular RNAs (circRNAs) are a class of noncoding RNAs that have been found to be involved in intervertebral disc degeneration (IVDD) progression, and N6-methyladenosine (m6A) broadly exists in circRNAs. Here, we identified circGPATCH2L with a low m6A methylation level to be upregulated in degenerative nucleus pulposus tissues. Mechanistically, as a protein decoy for tripartite motif containing 28 (TRIM28) within aa 402-452 region, circGPATCH2L abrogates the phosphorylation of TRIM28 and inhibits P53 degradation, which contributes to DNA damage accumulation and cellular apoptosis and leads to IVDD progression. Moreover, m6A-methylated circGPATCH2L is recognised and endoribonucleolytically cleaved by a YTHDF2-RPL10-RNase P/MRP complex to maintain the physiological state of nucleus pulposus cells. Thus, our data show the physiological significance of m6A modification in regulating circRNA abundance and provide a potentially effective therapeutic target for the treatment of IVDD.

Molecular and Cellular Mechanisms of Neuropathic Pain in Aging.

Neuropathic pain is a chronic condition that tends to worsen over time, leading to a significant decline in patients' quality of life. The elderly population is disproportionately affected by this burden, as evidenced by the high prevalence of this condition in such a demographic. While previous studies have demonstrated the involvement of various signaling pathways critical to neuropathic pain, the relationship between aging and the onset or persistence of this condition has been overlooked. Greater focus was placed on the efficacy and tolerability of medications, as well as new protocols for assessing pain in patients with cognitive impairment, with less regard for reasons underlying the increased susceptibility of elderly individuals to pain. This Review thus aims to summarize the contributions of aging to neuropathic pain, covering weakened repair function, increased intracellular calcium signaling, enhanced oxidative stress, dysfunctional brain function, impaired descending inhibition, alterations in the innate immune cell population, and the effects of comorbidity caused by aging. A better understanding of these aspects could drive new treatment options thereby yielding better outcomes for elderly patients in pain.

The Influence of Roussouly Type on the Prevalence, Subtype, and Distribution Characteristics of Modic Changes in Patients with Lumbar Degenerative Disc Disease.

BACKGROUND: The relationship between Roussouly type and Modic changes (MC) is unknown. The aim of our study was to investigate the influence of Roussouly type on the characteristics of MC in patients with lumbar degenerative disc disease. METHODS: This cross-sectional observational study from Huashan Hospital included 270 patients with lumbar degenerative disc disease. Subjects were divided into 4 groups according to the Roussouly classification. Prevalence, subtype, and distribution characteristics of MC from L1-L2 upper end plate to L5-S1 lower end plate were compared between 4 Roussouly types. RESULTS: Of 270 patients, 65 (24.1%) were Roussouly type I, 115 (42.6%) were Roussouly type II, 55 (20.4%) were Roussouly type III, and 35 (13.0%) were Roussouly type IV. MC were present in 45.9% (n = 270) of patients, 12.7% (n = 2700) of end plates, and 11.8% (n = 1350) of intervertebral discs. The prevalence rate of MC by subtype and intervertebral disc among the 4 Roussouly types was statistically different (P < 0.05), and the prevalence rate of MC by intervertebral disc in Roussouly type I was statistically higher than the other 3 Roussouly types. In Roussouly types I and IV, the prevalence rate of MC at L4-L5 level showed no significant differences compared with those at upper lumbar levels, while in Roussouly types II and III, the prevalence rate of MC at L4-L5 level was significantly higher than those at upper lumbar levels. CONCLUSIONS: Roussouly types can influence prevalence, subtype, and distribution characteristics of MC in patients with lumbar degenerative disc disease.

Two new sesquiterpenoids from the roots of Sarcandra glabra.

Two new sesquiterpenoids, sarglanoids G and H (1 and 2), together with two known analogues (3-4) were isolated from the roots of Sarcandra glabra. Compound 2 was a rare elemene-type sesquiterpenoid with a furan ring fragment, which is mostly lactone ring in its analogues. The structures of new compounds were determined on the basis of extensive spectroscopic methods including HR-ESI-MS, 1D and 2D NMR, and the absolute configuration of 1 was established by ECD calculations. Their anti-inflammatory activities were also evaluated.

Effect of three natural antioxidants on the structure and physicochemical properties of sweet potato starch noodles.

The study aimed to investigate the effect of three kinds of natural antioxidants (NAs), such as curcumin, tea polyphenols (TP), and lycopene, on sweet potato starch's structure and physicochemical properties of starch noodles. We found that the broken rates, iodine blue values, hardness, and chewiness of natural antioxidant starch noodles (NASN) were increased with the addition of the NAs. Additionally, the elasticity decreased with the addition of curcumin and lycopene, but it increased with the addition of TP. The cross-section structure of NASN obtained by scanning electron microscope (SEM) showed more holes appeared when adding NAs, and the additional amount had a pronounced effect on the microstructure of starch noodles (SN) regardless of the kind of NA added. The X-ray diffraction detection showed that some crystal forms were significantly damaged, and the addition of NAs affected the crystallization process of starch and produced a small proportion of new crystals in the NASNs. The protective effects of SN on NAs and their antioxidant capacities under dry and room temperature storage (DRTS) and wet and frozen storage (WFS) conditions were optimal as compared to those of flour noodles (FN). The results showed that adding NAs could improve the sensory quality and antioxidant function of starch noodles. In turn, the dense structure of starch noodles can also have a significant protective effect on antioxidants and their antioxidant activities, which is especially obvious under WFS conditions.

Prevalence of proximate risk factors of active tuberculosis in latent tuberculosis infection: A cross-sectional study from South India.

The prevalence of proximate risk factors for active tuberculosis (TB) in areas of high prevalence of latent tuberculosis infection (LTBI) is not clearly understood. We aimed at assessing the prevalence of non-communicable multi-morbidity focusing on diabetes mellitus (DM), malnutrition, and hypertension (HTN) as common risk factors of LTBI progressing to active TB. In a cross-sectional study, 2,351 adults (45% male and 55% female) from villages in the Kancheepuram district of South India were enrolled between 2013 and 2020. DM was defined as HbA1c >6.4%, undernutrition was defined as low body mass index (LBMI) <18.5 kg/m2, obesity was classified as BMI ≥25 kg/m2, HTN was reported as systolic pressure >130 mmHg, and LTBI was defined as positive (≥ 0.35 international units/ml) by QuantiFERON Gold In-Tube assay. A total of 1,226 individuals (52%) were positive for LTBI out of 2351 tested individuals. The prevalence of DM and pre-diabetes mellitus (PDM) was 21 and 35%, respectively, HTN was 15% in latent tuberculosis (LTB)-infected individuals. The association of DM [odds ratio (OR)]; adjusted odds ratio (aOR) (OR = 1.26, 95% CI: 1.13-1.65; aOR = 1.19, 95% CI: 1.10-1.58), PDM (OR = 1.11, 95% CI: 1.0-1.35), and HTN (OR = 1.28, 95% CI: 1.11-1.62; aOR = 1.18, 95% CI: 1.0-1.56) poses as risk factors of LTBI progression to active TB. The prevalence of LBMI 9% (OR = 1.07, 95% CI: 0.78-1.48) and obesity 42% (OR = 0.85, 95% CI: 0.70-1.03) did not show any statistically significant association with LTB-infected individuals. The present evidence of a high burden of multi-morbidity suggests that proximate risk factors of active TB in LTBI can be managed by nutrition and lifestyle modification.

Seroprevalence of Strongyloides stercoralis infection in a South Indian adult population.

BACKGROUND: The prevalence of Strongyloides stercoralis infection is estimated to be 30-100 million worldwide, although this an underestimate. Most cases remain undiagnosed due to the asymptomatic nature of the infection. We wanted to estimate the seroprevalence of S. stercoralis infection in a South Indian adult population. METHODS: To this end, we performed community-based screening of 2351 individuals (aged 18-65) in Kanchipuram District of Tamil Nadu between 2013 and 2020. Serological testing for S. stercoralis was performed using the NIE ELISA. RESULTS: Our data shows a seroprevalence of 33% (768/2351) for S. stercoralis infection which had a higher prevalence among males 36% (386/1069) than among females 29.8% (382/1282). Adults aged ≥55 (aOR = 1.65, 95% CI: 1.25-2.18) showed higher adjusted odds of association compared with other age groups. Eosinophil levels (39%) (aOR = 1.43, 95% CI: 1.19-1.74) and hemoglobin levels (24%) (aOR = 1.25, 95% CI: 1.11-1.53) were significantly associated with S. stercoralis infection. In contrast, low BMI (aOR = 1.15, 95% CI: 0.82-1.61) or the presence of diabetes mellitus (OR = 1.18, 95% CI: 0.83-1.69) was not associated with S. stercoralis seropositivity. CONCLUSIONS: Our study provides evidence for a very high baseline prevalence of S. stercoralis infection in South Indian communities and this information could provide realistic and concrete planning of control measures.

Sarglaromatics A-E: A Class of Naphthalene-Like Architecture Fused Norlindenane Sesquiterpene Dimers from Sarcandra glabra.

Sarglaromatics A-E (1-5, respectively), five unprecedented naphthalene-like architecture-fused norlindenane sesquiterpene dimers, were discovered from the roots of Sarcandra glabra. The unique naphthalene core skeleton was obtained from classical lindenane [4 + 2] dimers via a free-radical-mediated C11-C11' bond formation reaction and 12'-decarboxylation. The highly fused octonary ring skeleton was elucidated by HRMS, NMR, ECD, quantum chemical calculations, and biogenetic inspiration. Compounds 1 and 2 showed significant anti-nonalcoholic steatohepatitis (NASH) activity by inhibiting lipid deposition in L02 cells.

Electron angular correlation in nonsequential double ionization of molecules by counter-rotating two-color circularly polarized fields.

Electron correlation in nonsequential double ionization (NSDI) of molecules by counter-rotating two-color circularly polarized (TCCP) fields is investigated with a three-dimensional classical ensemble model. Numerical results indicate that the two electrons from NSDI of molecules in counter-rotating TCCP fields show strong angular correlation and the angular correlation behavior sensitively depends on the internuclear distance. With the internuclear distance increasing, the dominant behavior of electron pairs evolves from correlation to anti-correlation. It leaves a clear imprint on the ion momentum distributions, which exhibit an inverted Y-shape distribution at a small internuclear distance and a triangle-shape distribution at a large internuclear distance. Back analysis indicates that the asymmetric electron energy sharing by soft recollision and longer time delay of double ionization are responsible for more anti-correlated emissions at large internuclear distances.

Melatonin Alleviates Radiculopathy Against Apoptosis and NLRP3 Inflammasomes Via the Parkin-Mediated Mitophagy Pathway.

STUDY DESIGN: Animal experimental study with intervention. OBJECTIVE: To investigate the effect of melatonin on rat radiculopathy model and dorsal root ganglion (DRG) cells, and to elucidate the underlying mechanism. SUMMARY OF BACKGROUND DATA: Melatonin has a well-documented efficacy in intervertebral disc degeneration (IVDD) and low back pain. IVDD can also lead to other complications such as disc herniation which will cause radiculopathy. Herniated nucleus pulposus (NP) induced apoptosis and NLR pyrin domain containing 3 (NLRP3) activation in DRG. However, the effect and underlying mechanism of melatonin on radiculopathy and DRG cells are still unclear. METHODS: Rat radiculopathy model was induced by implanting NP tissue from the tail disc of the same rat into the left L4/5 inter-laminar space near the left DRG. Melatonin was injected intraperitoneally in the treated group to test its function. Apoptosis was determined by Tunnel staining and flow cytometry. NLRP3 inflammasome activation was determined by levels of NLRP3, ASC, GSMDM-N, IL-1ß, and Caspase-1. Mitophagy was determined by levels of Parkin, Beclin-1, p62, and LCB-II. Mitophagy was blocked by treatment with Parkin-si or cyclosporine A (CsA). RESULTS: NLRP3 was significantly upregulated in DRG of rat radiculopathy model; moreover, melatonin markedly decreased pain behavior in rat radiculopathy model. Furthermore, melatonin treatment decreases the incidence of apoptosis in DRG cells. Melatonin also promotes mitophagy and inhibits NLRP3 inflammasomes in DRG cells. In addition, mitophagy was blocked by treatment with Parkin-si and CsA. Both Parkin-si and CsA attenuated melatonin's inhibitory effect on apoptosis and the NLRP3 inflammasome, indicating that the beneficial effects of melatonin in DRG cells are mediated through the Parkin-mediated mitophagy. CONCLUSION: Melatonin alleviates radiculopathy against apoptosis and NLRP3 inflammasomes by promoting Parkin-mediated mitophagy, which may help us provide a potential target for the treatment of radiculopathy.Level of Evidence: N/A.

MSC-Derived Exosomes Protect Vertebral Endplate Chondrocytes against Apoptosis and Calcification via the miR-31-5p/ATF6 Axis.

Apoptosis and calcification of endplate chondrocytes (EPCs) can exacerbate intervertebral disc degeneration (IVDD). Mesenchymal stem cell-derived exosomes (MSC-exosomes) are reported to have the therapeutic potential in IVDD. However, the effects and related mechanisms of MSC-exosomes on EPCs are still unclear. We aimed to investigate the role of MSC-exosomes on EPCs with a tert-butyl hydroperoxide (TBHP)-induced oxidative stress cell model and IVDD rat model. First, our study revealed that TBHP could result in apoptosis and calcification of EPCs, and MSC-exosomes could inhibit the detrimental effects. We also found that these protective effects were inhibited after miroRNA (miR)-31-5p levels were downregulated in MSC-exosomes. The target relationship between miR-31-5p and ATF6 was tested. miR-31-5p negatively regulated ATF6-related endoplasmic reticulum (ER) stress and inhibited apoptosis and calcification in EPCs. Our in vivo experiments indicated that sub-endplate injection of MSC-exosomes can ameliorate IVDD; however, after miR-31-5p levels were downregulated in MSC-exosomes, these protective effects were inhibited. In conclusion, MSC-exosomes reduced apoptosis and calcification in EPCs, and the underlying mechanism may be related to miR-31-5p/ATF6/ER stress pathway regulation.

Ligand-Free Copper(I)-Mediated Cross-Coupling Reactions of Organostannanes with Sulfur Electrophiles.

The synthesis of aryl thioether through the cross-coupling of C-S bond is a highly attractive area of research due to the prevalence of aryl thioether in bioactive natural products, functional materials, agrochemicals, and pharmaceutically active compounds. Herein, we report a ligand-free Cu(I) mediated electrophilic thiolation of organostannanes with sulfur electrophiles. A selective transfer of alkyl groups was achieved in reactions with alkyl carbastannatranes affording congested thioethers. This study offers a unified method to access diaryl and aryl alkyl thioethers and was demonstrated in the context of late-stage modifications..

Combined culture experiment of mouse bone marrow mesenchymal stem cells and bioceramic scaffolds.

Articular cartilage injuries are common orthopedic conditions that severely affect the quality of life of patients. Tissue engineering can facilitate cartilage repair and the key points involve scaffolding and seed cell selection. Pre-experiments found a range of microstructures of bioceramic scaffolds suitable for chondrocyte adhesion and proliferation, and maintaining chondrocyte phenotype. Three-dimensional cultures of bone marrow mesenchymal stem cell (BMSC) scaffolds were implanted into mice. According to the shape of the bioceramic scaffolds and the implantation time in vivo, RNA sequencing was performed on the removed scaffolds to explore the molecular mechanism. The in vitro bone plate culture can induce differentiation of chondrocytes, making culture different to that produced in vitro. Implantation of scaffolds in vivo increases the expression of bone-related genes. The ceramic rod-like material was found to be superior to the disc shape, and the bone repair effect was more marked with longer implantation times. Gene Ontology analysis revealed that 'cell chemotaxis', 'negative regulation of ossification' and 'bone development' pathways were involved in recovery. It was further confirmed that BMSCs were suitable as seed cells for cartilage tissue engineering, and that the ß-tricalcium phosphate scaffold maybe ideal as cartilage tissue engineering scaffold material. The present research provided new insights into the molecular mechanism of cartilage repair by BMSCs and bioceramic scaffolds. Bioinformatics analysis revealed that AMMECR1L-like protein, tumor necrosis factor-induced protein 2, inhibitor of nuclear factor-B kinase subunit and protein kinase C type and 'negative regulation of ossification' and 'bone development' pathways may be involved in osteoblast maturation and bone regeneration.

Exosome-Transported circRNA_0000253 Competitively Adsorbs MicroRNA-141-5p and Increases IDD.

The pathogenesis of intervertebral disc degeneration (IDD) is complex, and a better understanding of IDD pathogenesis may provide a better method for the treatment of IDD. Exosomes are 40-100 nm nanosized vesicles that are released from many cell types into the extracellular space. We speculated that exosome-transported circular RNAs (circRNAs) could regulate IDD. Exosomes from different degenerative grades were isolated and added to nucleus pulposus cells (NPCs), and indicators of proliferation and apoptosis were detected. Based on the previous circRNA microarray results, the top 10 circRNAs were selected. PCR was performed to determine the circRNA with the maximum upregulation. Competing endogenous RNA (ceRNA) analysis was carried out, and the sponged microRNA (miRNA) was identified. Further functional verification of the selected circRNA was carried out in vivo and in vitro. NPCs of different degenerative grades secreted exosomes, which could regulate IDD. circRNA_0000253 was selected as having the maximum upregulation in degenerative NPC exosomes. ceRNA analysis showed that circRNA_0000253 could adsorb miRNA-141-5p to downregulate SIRT1. circRNA_0000253 was confirmed to increase IDD by adsorbing miRNA-141-5p and downregulating SIRT1 in vivo and in vitro. Exosomal circRNA_0000253 owns the maximum upregulation in degenerative NPC exosomes and could promote IDD by adsorbing miRNA-141-5p and downregulating SIRT1.

Catalytic and Photochemical Strategies to Stabilized Radicals Based on Anomeric Nucleophiles.

Carbohydrates, one of the three primary macromolecules of living organisms, play significant roles in various biological processes such as intercellular communication, cell recognition, and immune activity. While the majority of established methods for the installation of carbohydrates through the anomeric carbon rely on nucleophilic displacement, anomeric radicals represent an attractive alternative because of their functional group compatibility and high anomeric selectivities. Herein, we demonstrate that anomeric nucleophiles such as C1 stannanes can be converted into anomeric radicals by merging Cu(I) catalysis with blue light irradiation to achieve highly stereoselective C(sp3)-S cross-coupling reactions. Mechanistic studies and DFT calculations revealed that the C-S bond-forming step occurs via the transfer of the anomeric radical directly to a sulfur electrophile bound to Cu(II) species. This pathway complements a radical chain observed for photochemical metal-free conditions where a disulfide initiator can be activated by a Lewis base additive. Both strategies utilize anomeric nucleophiles as efficient radical donors and achieve a switch from an ionic to a radical pathway. Taken together, the stability of glycosyl nucleophiles, a broad substrate scope, and high anomeric selectivities observed for the thermal and photochemical protocols make this novel C-S cross coupling a practical tool for late-stage glycodiversification of bioactive natural products and drug candidates.

Motor unit number index in quantitatively assessing motor root lesions and monitoring treatment outcomes in patients with lumbosacral radiculopathy.

INTRODUCTION: We investigated the feasibility of motor unit number index (MUNIX) in quantitatively assessing motor root lesions and tracking different treatment outcomes in lumbosacral radiculopathy (LR). METHODS: Bilateral MUNIX was recorded from the abductor hallucis, extensor digitorum brevis, and tibialis anterior in 44 normal controls and 108 patients with LR, and this was repeated approximately 12 months after treatment in 60 patients with LR. RESULTS: More abnormalities were observed when side-to-side differences of MUNIX measurements were used to evaluate LR (P < .05). Motor unit number index measurements worsened without progression of muscle weakness after conservative treatment, and MUNIX measurements improved with or without increased muscle strength after surgical treatment (P < .05). DISCUSSION: Motor unit number index may identify a specific L5 or S1 motor root lesion even before muscle weakness occurs, especially when side-to-side differences are used. Changes in MUNIX were larger than those in motor function measures after treatments for LR.

Bibliometric and Visualized Analysis of Scientific Publications on Atlantoaxial Spine Surgery Based on Web of Science and VOSviewer.

BACKGROUND: Atlantoaxial spine surgery is a challenge to spinal surgeons because of its proximity to neurovascular structures. This study aimed to identify and analyze the scientific publications in atlantoaxial spine surgery from different countries and institutions. METHODS: Clarivate Analytics Web of Science was used to search all articles for information on atlantoaxial spine surgery. The annual research, countries, journals, authors, institutions, citation frequency, and journal metrics were extracted. These results from countries and hotspots (keywords in publications) were subjected to co-occurrence analysis using VOSviewer, after which the top 100 most-cited articles were analyzed further. RESULTS: A total of 3161 articles were included. A trend toward an increasing number of publications on atlantoaxial spine surgery in recent years was evident. Among all countries, the United States contributed the most publications. Seth Gordhandas Sundarda Medical College had the highest number of publications among institutions. Among all research categories, fixation and fusion were the most common areas discussed. The screw-rod system described in the most-cited article (cited 823 times) appeared to be the most popular fixation method. With the development of C1 and C2 screw technology, the screw-rod system is becoming increasingly popular. CONCLUSIONS: The atlantoaxial spine surgery literature has grown continuously in recent years. The United States is the largest contributor in this field. Fixation and fusion are the most common areas, and fixation-related studies should be closely followed. The screw-rod fixation system is becoming increasingly popular.