Health outcomes of COVID-19 patients from Wuhan, China 3-year after hospital discharge: a cohort study.

OBJECTIVES: To evaluate changes in health outcomes between years 2 and 3 after discharge following COVID-19 and to identify risk factors for poor health 3-year post-discharge. DESIGN: This is a multicentre observational cohort study. SETTING: This study was conducted in two centres from Wuhan, China. PARTICIPANTS: Eligibility screening has been performed in 3988 discharged laboratory-confirmed adult COVID-19 patients. Exclusion criteria were refusal to participate, inability to contact and death before follow-up. The WHO COVID-19 guidelines on defining disease severity were adopted. RESULTS: 1594 patients participated in the 1-year, 2-year and 3-year follow-ups, including 796 (49.9%) male patients, and 422 (26.5%) patients were classified in the severe disease group. 3 years after discharge, 182 (11.4%) patients still complained of at least one symptom. The most common symptoms were fatigue, myalgia, chest tightness, cough, anxiety, shortness of breath and expectoration. Fatigue or myalgia, the most common symptom cluster, frequently coexisted with chest symptoms and anxiety. Symptom persistence between years 2 and 3 was reported in 70 patients (4.4%) for which intensive care unit (ICU) admission was a risk factor (p=0.038). Of the 1586 patients who completed the chronic obstructive pulmonary disease assessment test (CAT), 97 (6.1%) scored ≥10, with older age being associated with CAT ≥10 (p=0.007). CONCLUSIONS: Between years 2 and 3 after SARS-CoV-2 infection, most patients returned to an asymptomatic state, and only a few were still symptomatic. ICU admission was a risk factor for symptom persistence.

Kappa opioid receptor availability predicts severity of anhedonia in schizophrenia.

The kappa opioid receptor (KOR) and its endogenous agonist dynorphin have been implicated in multiple psychiatric conditions including psychotic disorders. We tested the hypotheses that kappa expression is elevated and associated with psychotic symptoms in schizophrenia. We measured kappa expression in unmedicated patients with schizophrenia (7 female, 6 male) and matched controls (7 female, 6 male) with positron emission tomography (PET). We also acquired a measurement of cumulative dopamine activity over the life span in the same subjects using neuromelanin sensitive MRI. We hypothesized that neuromelanin accumulation would be higher in patients than controls and that in patients there would be a positive association between KOR availability and neuromelanin accumulation. Fourteen patients and thirteen controls were enrolled. Whole brain dynamic PET imaging data using the KOR selective tracer [18F]LY245998 were acquired. Distribution volume (VT) was measured with region of interest analysis in 14 brain regions. Neuromelanin accumulation in midbrain dopaminergic nuclei was assessed in the same subjects. Positive and negative symptoms were measured by a clinical psychologist. We did not observe group level differences in KOR expression, neuromelanin accumulation or relationships of these to positive symptoms. Unexpectedly, we did observe strong positive associations between KOR expression and symptoms of anhedonia in the patients (Pearson r > 0.7, uncorrected p < 0.01 in 8 cortical brain regions). We also observed moderate associations between KOR expression and neuromelanin levels in patients. In conclusion, we did not observe a relationship between kappa and symptoms of psychosis but the observed relationship to the negative symptom of anhedonia is in line with recent work testing kappa antagonism as a therapy for anhedonia in depression.

The potential utility of (2S,4R)-4-[18F] fluoroglutamine as a novel metabolic imaging marker for inflammation explored by rat models of arthritis and paw edema.

Purpose: (2S,4R)-4-[18F]fluoroglutamine ([18F]FGln) is a promising metabolic imaging marker in cancer. Based on the fact that major inflammatory cells are heavily dependent on glutamine metabolism like cancer cells, we explored the potential utility of [18F]FGln as a metabolic imaging marker for inflammation in two rat models: carrageenan-induced paw edema (CIPE) and collagen-induced arthritis (CIA). Procedures: The CIPE model (n = 4) was generated by injecting 200 µL of 3% carrageenan solution into the left hind paw three hours before the PET. The CIA model (n = 4) was generated by injecting 200 µg of collagen emulsion subcutaneously at the tail base 3-4 weeks before the PET. A qualitative scoring system was used to assess the severity of paw inflammation. After a CT scan, 15.7 ± 4.9 MBq of [18F]FGln was injected via the tail vein, followed by a dynamic micro-PET scan for 90 minutes under anesthesia with isoflurane. The standard uptake value of [18F]FGln was measured by placing a volume of interest in each paw. The non-injected right hind paws of the CIPE model rats served as controls for both models. The paws with CIA were pathologically examined after PET. Results: In CIPE models, uptake in the injected paw was higher compared to the non-injected paw by 52-83%. In CIA models, uptake in the paws with severe inflammation was higher than the averaged controls by 54-173%, while that with mild and no inflammation was slightly higher (33%) and lower (-7%), respectively. Combined overall, the [18F]FGln uptake in CIA showed a significant positive correlation with inflammation severity (r = 0.88, P = 0.009). The pathological findings confirmed profound inflammation in CIA. Conclusions: [18F]FGln uptake was increased in both acute and chronic inflammation, and the uptake level was significantly correlated with the severity, suggesting its potential utility as a novel metabolic imaging marker for inflammation.

Synthesis and Biological Evaluation of Fluorine-18 and Deuterium Labeled l-Fluoroalanines as Positron Emission Tomography Imaging Agents for Cancer Detection.

To fully explore the potential of 18F-labeled l-fluoroalanine for imaging cancer and other chronic diseases, a simple and mild radiosynthesis method has been established to produce optically pure l-3-[18F]fluoroalanine (l-[18F]FAla), using a serine-derivatized, five-membered-ring sulfamidate as the radiofluorination precursor. A deuterated analogue, l-3-[18F]fluoroalanine-d3 (l-[18F]FAla-d3), was also prepared to improve metabolic stability. Both l-[18F]FAla and l-[18F]FAla-d3 were rapidly taken up by 9L/lacZ, MIA PaCa-2, and U87MG cells and were shown to be substrates for the alanine-serine-cysteine (ASC) amino acid transporter. The ability of l-[18F]FAla, l-[18F]FAla-d3, and the d-enantiomer, d-[18F]FAla-d3, to image tumors was evaluated in U87MG tumor-bearing mice. Despite the significant bone uptake was observed for both l-[18F]FAla and l-[18F]FAla-d3, the latter had enhanced tumor uptake compared to l-[18F]FAla, and d-[18F]FAla-d3 was not specifically taken up by the tumors. The enhanced tumor uptake of l-[18F]FAla-d3 compared with its nondeuterated counterpart, l-[18F]FAla, warranted the further biological investigation of this radiotracer as a potential cancer imaging agent.

Digital financial inclusion, industrial structure and urban-Rural income disparity: Evidence from Zhejiang Province, China.

Rising income inequality challenges economic and social stability in developing countries. For China, the fastest-growing global digital economy, it could be an effective tool to promote inclusive development, narrowing urban-rural income disparity. It investigates the role of digital financial inclusion (DFI) in narrowing the urban-rural income gap. The study uses panel data from 52 counties in Zhejiang Province, China, from 2014 to 2020. The results show that the development of DFI significantly reduces rural-urban and rural income inequality. The development of DFI helps optimize industrial structure and upgrade the internal structure of agriculture, facilitating income growth for people in rural areas. Such effects are greater in poorer counties. Our findings provide insights into why rapid DFI and the narrowing of the rural-urban income disparity exist in China. Moreover, our results provide clear policy implications on how to reduce the disparity. The most compelling suggestion is that promoting the optimization of industrial structure through DFI is crucial for narrowing the urban-rural income gap.

Development and validation of a deep-learning model for the detection of non-displaced femoral neck fractures with anteroposterior and lateral hip radiographs.

Background: Hip fractures, including femoral neck fractures, are a significant cause of morbidity and mortality in the elderly population and are typically diagnosed using plain radiography. However, diagnosing non-displaced femoral neck fractures can be challenging due to their subtle appearance on hip radiographs. Previous deep-learning models have shown low accuracy in identifying these fractures on anteroposterior (AP) radiographs; however, no studies have used lateral radiographs. This study aimed to evaluate the potential of using deep-learning with both AP and lateral hip radiographs to automatically identify non-displaced femoral neck fractures. Methods: We conducted a retrospective analysis of patients with femoral neck fractures at The First Affiliated Hospital of Xiamen University. All the hip radiographs were reviewed, and cases of non-displaced femoral neck fractures were included in the study. Additionally, 439 participants with normal hip radiographs were also included in the study. A vision transformer (Vit) model was developed using 1,536 AP and lateral hip radiograph. The model's performance was compared to the performance of two groups of human observers: an expert group comprising orthopedic surgeons and radiologists, and a non-expert group, including emergency physicians and general practice doctors. We also carried out the external validation using two additional data sets to assess the generalizability of the model. Results: The Vit model showed exceptional performance in detecting non-displaced femoral neck fractures on paired AP and lateral hip radiographs, achieving a binary accuracy of 95.8% [95% confidence interval (CI): 94.9%, 96.8%] and an area under the curve (AUC) of 0.988. Compared to the human observers, the model had a higher accuracy of 96.7% (95% CI: 93.9%, 99.5%) on the paired AP and lateral hip radiographs, while the accuracy of the expert group was 90.5% (95% CI: 85.7%, 95.2%). Further, the model maintained good performance during the external validation, with an AUC of 0.959 on the paired AP and lateral views. Conclusions: Our Vit model showed expert-level performance in identifying non-displaced femoral neck fractures on paired AP and lateral hip radiographs. This model has the potential to enhance diagnosis accuracy and improve patient outcomes by reducing the need for additional examinations and preoperative time.

Water storage capacity is inversely associated with xylem embolism resistance in tropical karst tree species.

Tropical karst habitats are characterized by limited and patchy soil, large rocky outcrops and porous substrates, resulting in high habitat heterogeneity and soil moisture fluctuations. Xylem hydraulic efficiency and safety can determine the drought adaptation and spatial distribution of woody plants growing in karst environments. In this study, we measured sapwood-specific hydraulic conductivity (Ks), vulnerability to embolism, wood density, saturated water content, and vessel and pit anatomical characteristics in the branch stems of 12 evergreen tree species in a tropical karst seasonal rainforest in southwestern China. We aimed to characterize the effects of structural characteristics on hydraulic efficiency and safety. Our results showed that there was no significant correlation between Ks and hydraulic safety across the tropical karst woody species. Ks was correlated with hydraulic vessel diameter (r = 0.80, P < 0.05) and vessel density (r = -0.60, P < 0.05), while the stem water potential at 50 and 88% loss of hydraulic conductivity (P50 and P88) were both significantly correlated with wood density (P < 0.05) and saturated water content (P = 0.052 and P < 0.05, respectively). High stem water storage capacity was associated with low cavitation resistance possibly because of its buffering the moisture fluctuations in karst environments. However, both Ks and P50/P88 were decoupled from the anatomical traits of pit and pit membranes. This may explain the lack of tradeoff between hydraulic safety and efficiency in tropical karst evergreen tree species. Our results suggest that diverse hydraulic trait combination may facilitate species coexistence in karst environments with high spatial heterogeneity.

Human neural stem cells.

'Human neural stem cells' jointly drafted and agreed upon by experts from the Chinese Society for Stem Cell Research, is the first guideline for human neural stem cells (hNSCs) in China. This standard specifies the technical requirements, test methods, test regulations, instructions for use, labelling requirements, packaging requirements, storage requirements, transportation requirements and waste disposal requirements for hNSCs, which is applicable to the quality control for hNSCs. It was originally released by the China Society for Cell Biology on 30 August 2022. We hope that publication of the guideline will facilitate institutional establishment, acceptance and execution of proper protocols, and accelerate the international standardization of hNSCs for clinical development and therapeutic applications.

Human midbrain dopaminergic progenitors.

Human midbrain dopaminergic progenitors (mDAPs) are one of the most representative cell types in both basic research and clinical applications. However, there are still many challenges for the preparation and quality control of mDAPs, such as the lack of standards. Therefore, the establishment of critical quality attributes and technical specifications for mDAPs is largely needed. "Human midbrain dopaminergic progenitor" jointly drafted and agreed upon by experts from the Chinese Society for Stem Cell Research, is the first guideline for human mDAPs in China. This standard specifies the technical requirements, test methods, inspection rules, instructions for usage, labelling requirements, packaging requirements, storage requirements, transportation requirements and waste disposal requirements for human mDAPs, which is applicable to the quality control for human mDAPs. It was originally released by the China Society for Cell Biology on 30 August 2022. We hope that the publication of this guideline will facilitate the institutional establishment, acceptance and execution of proper protocols, and accelerate the international standardization of human mDAPs for clinical development and therapeutic applications.

An improved synthesis of [18 F]VAT and its precursor.

The vesicular acetylcholine transporter (VAChT) in the brain is an important presynaptic cholinergic biomarker, and neuroimaging studies of VAChT may provide in vivo information about psychiatric and neurologic conditions including Alzheimer's disease that are not accessible by other methods. The 18 F-labeled radiotracer, ((-)-(1-(-8-(2-[18 F]fluoroethoxy)-3-hydroxy-1,2,3,4-tetrahydronaphthalen-2-yl)piperidin-4-yl)(4-fluorophenyl)-methanone ([18 F]VAT, 1), was reported as a selective and high affinity ligand for the in vivo imaging of VAChT. The synthesis of [18 F]VAT has been reported in a two-step procedure with total 140 min, which includes preparation of 2-[18 F]fluoroethyltosylate and alkylation of benzovesamicol (-)-5 precursor with this radiosynthon using two different automated production modules consecutively. A multiple step synthetic route was employed for the synthesis of stereospecific precursor benzovesamicol (-)-5, which is difficult to be adapted for scale-up. To make the production of this tracer more amenable for clinical imaging, we present an improved total synthesis protocol to attain [18 F]VAT: (1) a tosylethoxy group being pre-installed tosylate precursor (-)-8 is synthesized to render a simple one-step radiofluorination under mild conditions; (2) The key optically active intermediate benzovesamicol (-)-5 was obtained via the regio- and enantio-enriched ring-opening amination of meso-epoxide 3 with 4-phenylpiperidine derivative 2 under catalysis of a chiral salenCo(III) catalyst 4b, which dramatically simplifies the synthetic route of the tosylate precursor (-)-8. [18 F]VAT 1 was prepared within ~65 min with desired chemical and radiochemical purities, via a fully automated procedure, using a commercial PET tracer production module. The final drug product was obtained as a sterile, pyrogen-free solution that conforms United States Pharmacopeia (USP) <823> requirements.

Comparison of Full Endoscopic Lumbar Diskectomy Using the Transforaminal Approach versus Interlaminar Approach for L5-S1 Lumbar Disk Herniation Treatment: A Meta-Analysis.

BACKGROUND: Numerous studies have examined the clinical effectiveness of transforaminal full endoscopic lumbar diskectomy (T-FELD) and interlaminar full endoscopic lumbar diskectomy (I-FELD) for L5-S1 lumbar disk herniation (LDH), with mixed findings. The goal of this systematic review and meta-analysis was to evaluate the perioperative outcomes, clinical results, and complications of T-FELD and I-FELD to determine their efficacy and safety for treating L5-S1 LDH and to examine the features of complications in depth. METHODS: Several databases were searched for articles that matched all of the inclusion criteria. The visual analog scale (VAS) and Oswestry Disability Index (ODI) were used to assess the clinical results. Information on perioperative outcomes and complications was gathered and analyzed. RESULTS: Eight studies with 756 participants were included. There were no significant differences in postoperative bed time (p = 0.44) and hospitalization time (p = 0.49) between T-FELD and I-FELD. When compared with I-FELD, T-FELD was associated with substantially longer fluoroscopy time (p < 0.0001) and operating time (p < 0.0001). There were no significant differences in the preoperative and postoperative VAS and ODI scores between T-FELD and I-FELD. The rates for overall complications, postoperative dysesthesia, postoperative lower extremity pain, incomplete decompression, recurrence, and conversion to open surgery were comparable for T-FLED and I-FELD. CONCLUSION: T-FELD and I-FELD had equal clinical results and safety for treatment of L5-S1 LDH. Fluoroscopy and operative times were shorter for I-FELD than for T-FELD.

Machine learning versus crop growth models: an ally, not a rival.

The rapid increases of the global population and climate change pose major challenges to a sustainable production of food to meet consumer demands. Process-based models (PBMs) have long been used in agricultural crop production for predicting yield and understanding the environmental regulation of plant physiological processes and its consequences for crop growth and development. In recent years, with the increasing use of sensor and communication technologies for data acquisition in agriculture, machine learning (ML) has become a popular tool in yield prediction (especially on a large scale) and phenotyping. Both PBMs and ML are frequently used in studies on major challenges in crop production and each has its own advantages and drawbacks. We propose to combine PBMs and ML given their intrinsic complementarity, to develop knowledge- and data-driven modelling (KDDM) with high prediction accuracy as well as good interpretability. Parallel, serial and modular structures are three main modes can be adopted to develop KDDM for agricultural applications. The KDDM approach helps to simplify model parameterization by making use of sensor data and improves the accuracy of yield prediction. Furthermore, the KDDM approach has great potential to expand the boundary of current crop models to allow upscaling towards a farm, regional or global level and downscaling to the gene-to-cell level. The KDDM approach is a promising way of combining simulation models in agriculture with the fast developments in data science while mechanisms of many genetic and physiological processes are still under investigation, especially at the nexus of increasing food production, mitigating climate change and achieving sustainability.

Letter to the editor regarding "Full­endoscopic (bi­portal or uni­portal) versus microscopic lumbar decompression laminectomy in patients with spinal stenosis: systematic review and meta­analysis".

A recent article entitled "Full­endoscopic (bi­portal or uni­portal) versus microscopic lumbar decompression laminectomy in patients with spinal stenosis: systematic review and meta­analysis" written by Pairuchvej et al. (Eur J Orthop Surg Traumatol 30(4):595-611, 2019) published in "European Journal of Orthopaedic Surgery & Traumatology" has aroused our great interest. The authors concluded that compared with minimally invasive decompression surgery, full endoscopic spinal surgery had better pain relief (back pain and leg pain) in the treatment of lumbar spinal stenosis and had a lower complication rate, but no statistical difference in oswestry disability index score and operative time between both groups. Comparing to minimally invasive spinal surgery, bi-portal endoscopic spinal surgery had better back pain relief in the early stage, while uni-portal full endoscopic spinal surgery had better pain relief in the leg and a lower rate of complications.

Research relating to three-dimensional (3D) printing in spine surgery: a bibliometric analysis.

PURPOSE: Although numerous publications on three-dimensional printing (3DP) in spine surgery have been published, bibliometric analysis studies are scarce. Thus, this study aimed to present a bibliometric analysis of the status, hot spots, and frontiers of 3DP in spine surgery and associated research disciplines. METHODS: All publications relating to the utilization of 3DP in spine surgery from 1999 to May 9, 2022, were retrieved from the Web of Science. The bibliometric analysis was performed using CiteSpace software, and information on the country, institution, author, journal, and keywords for each publication was collected. RESULTS: A total of 270 articles were identified. From 2016 onward, a significant increase in publications on spinal surgery was observed. China was the most productive and influential country (98 publications) and H-index (22), followed by the USA and Australia. The most productive institution was Capital Medical University (9 publications). P. S. D'urso (8 publications, 46 citations) and R. J. Mobbs (8 publications, 39 citations) were the most prolific authors. European Spine Journal contributed the highest number of publications. The eight main clusters were: "rapid prototyping" #0, "3D printed" #1, "spine fusion" #2, "scoliosis" #3, "spine surgery" #4, "patient-specific" #5, "nervous system" #6, and "neuronavigation" #7. The strongest keyword bursts in 3DP in spine surgery were "fixation," "drill template," "instrumentation," "fusion," "complication," and "atlantoaxial instability." CONCLUSION: This analysis provides information on research trends and frontiers in the application of 3DP in spine surgery, as well as research and collaboration partners, institutions, and countries.

Postoperative Pain Management after Full Endoscopic Lumbar Discectomy: An Observational Study.

Background: Surgical incision pain, rebound pain, and recurrence can manifest themselves in different forms of postoperative pain after full endoscopic lumbar discectomy (FELD). This study aims to evaluate various postoperative pains after FELD and summarize their characteristics. Methods: Data about the demographic characteristics of patients, pain intensity, and functional assessment results were collected from January 2016 to September 2019. Clinical outcomes including Oswestry Disability Index (ODI) and visual analog scale (VAS) scores, were obtained. Results: A total of 206 patients were enrolled. ODI and VAS of the patients significantly decreased after FELD at 12-month follow-up. A total of 193 (93.7%) patients had mild surgical incision pain after FELD and generally a VAS < 4, and it mostly resolved on its own within 3 days. A total of 12 (5.8%) patients experienced rebound pain, which was typically characterized by pain (mainly leg pain with or without back pain), generally occurring within 2 weeks after FELD and lasting < 3 weeks. The pain levels of rebound pain were equal to or less than those of preoperative pain, and generally scored a VAS of < 6. The recurrence rate was 4.4%. Recurrence often occurs within three months after surgery, with the pain level of the recurrence being greater than or equal to the preoperative pain. Conclusions: Different types of postoperative pain have their own unique characteristics and durations, and treatment options are also distinct. Conservative treatment and analgesia may be indicated for rebound pain and surgical incision pain, but recurrence usually requires surgical treatment.

A meta-analysis of clinical effects of microscopic unilateral laminectomy bilateral decompression (ULBD) versus biportal endoscopic ULBD for lumbar canal stenosis.

Osbjective: Several studies have shown that both microscopic unilateral laminotomy bilateral decompression (ULBD) and unilateral biportal endoscopic (UBE) ULBD are effective for treating lumbar canal stenosis (LCS). However, there are different viewpoints as to which surgical technique is superior. Therefore, this meta-analysis investigated the clinical efficacy and side effects of microscopic ULBD and UBE ULBD for treating LCS. Methods: To identify relevant studies describing the clinical outcomes and complication rates of microscopic ULBD and UBE ULBD for LCS, several databases were systematically searched in the Internet. The visual analog scale score for back and leg pain and the Oswestry Disability Index were used to assess clinical outcomes. Furthermore, data about perioperative outcomes and complications were documented. Results: In total, six studies with 450 participants were included in this meta-analysis. The UBE ULBD was found to be superior to microscopic ULBD in terms of efficacy against early postoperative back and leg pain. However, there was no significant difference between the two procedures in terms of final clinical outcomes and complications. In addition, compared with microscopic ULBD, UBE ULBD was associated with a significant reduction in the length of hospital stay and C-reactive protein levels 2 days after surgery. Conclusion: UBE ULBD and microscopic ULBD for the treatment of LCS were similar in terms of final clinical outcomes and complications. However, UBE ULBD has several advantages over microscopic ULBE, including a shorter hospital stay and faster alleviation of postoperative back and leg pain.

De Novo Assembly Transcriptome Analysis Reveals the Preliminary Molecular Mechanism of Primordium Formation in Pleurotus tuoliensis.

Primordium formation is extremely important for yield of Pleurotus tuoliensis. However, the molecular mechanism underlying primordium formation is largely unknown. This study investigated the transcriptional properties during primordium formation of P. tuoliensis by comparing transcriptome. Clean reads were assembled into 57,075 transcripts and 6874 unigenes. A total of 1397 differentially expressed genes were identified (26 DEGs altered in all stages). GO and KEGG enrichment analysis showed that these DEGs were involved in "oxidoreductase activity", "glycolysis/gluconeogenesis", "MAPK signaling pathways", and "ribosomes". Our results support further understanding of the transcriptional changes and molecular processes underlying primordium formation and differentiation of P. tuoliensis.

Characteristics and hotspots of the 50 most cited articles in the field of pre-psoas oblique lumbar interbody fusion.

Purpose: In the past decade, the field of pre-psoas oblique lumbar interbody fusion (OLIF) has developed rapidly, and with it, the literature on OLIF has grown considerably. This study was designed to analyze the top 50 articles in terms of the number of citations through bibliometric research to demonstrate the research characteristics and hotspots of OLIF. Method: Searching the Web of Science database yielded the 50 most cited publications in the OLIF field as of July 10, 2022. The publications were ranked according to the number of citations. The following sources were evaluated: the year of publications, the number of citations, authors, countries, institutions, journals, research topics, and keyword hotspots. Results: The most productive period was from 2017 to 2020, with 41 articles. The number of citations varied from 10 to 140, with an average of 35.52, and 1,776 citations were found. World Neurosurgery published the most articles (12), China produced the most articles (16), and the Catholic University of Korea produced the most studies (6). The corresponding author who produced the most articles was J.S. Kim (5), and the first author who produced the most publications was S. Orita (3). The main research topics were anatomical morphology, surgical techniques, indications, outcomes, and complications. The top 10 most cited keywords were "complications," "decompression," "spine," "surgery," "outcomes," "transpsoas approach," "spondylolisthesis," "anterior," "disease," and "injury." Conclusions: Certain articles can be distinguished from others using citation analysis as an accurate representation of their impact due to their long-term effectiveness and peer recognition. With these publications, researchers are provided with research priorities and hotspots through influential literature in the field of OLIF.

Global research hotspots and trends in the field of spine surgery during the COVID-19 pandemic: A bibliometric and visual analysis.

Background: The Coronavirus disease-2019 (COVID-19) significantly affected the healthcare and research systems, including spine surgery, throughout the world. A bibliometric analysis allows graphical visualization of the development of an academic field and its frontiers. Since research concerning spine surgery during the COVID-19 pandemic is being constantly upgraded, we conducted a bibliometric analysis of this literature to investigate the current status, research hotspots, and trends in this field. Methods: We searched the Web of Science database for literature published (from December 1, 2019, to March 24, 2022) using the terms "COVID-19" OR "2019-nCoV" OR "SARS-CoV-2" AND "spine surgery" OR "spinal surgery" OR "discectomy" OR "decompression" OR "laminectomy" OR "interbody fusion" OR "pedicle screws." Detailed bibliometric and visual analysis of the number of publications, geographical distribution, institutions, journals, authors, and keywords was done using CiteSpace, VOSviewer, and R-Bibliometrix. Results: Of the initially screened 173 articles, we included 84 relevant articles-62 original articles, 10 editorial materials, 8 reviews, and 4 others. The United States, China, Egypt, and Argentina were most actively publishing in the field of spine surgery and COVID-19. The AOSpine International community contributed 7 articles (24 citations). The Hospital for Special Surgery (13.1%) and Johns Hopkins University (13.1%) were institutions with the most publications. Using the Law of Bradford, we found that World Neurosurgery, Global Spine Journal, and European Spine Journal are the core journals in this field, with P. K. Louie being the most influential author. "Elective surgery," "intensive care," "telehealth," "patient satisfaction," and "follow-up" had the strongest citation bursts. Conclusions: During the COVID-19 pandemic, spine surgeons were more concerned with surgical timing, care, treatment, and patient's quality of life. Accordingly, research hotspots in spine surgery during the pandemic shifted from "early healthcare" to "virus management" and "experience and education."