Impacts of different slash disposals on soil and water erosion of high-intensity management Eucalyptus grandis × urophylla plantation.

Background: The slash disposal-burning forest-in high-intensity management Eucalyptus grandis × urophylla plantation has accelerated soil degradation. Statement of the problem: Slash disposals is a contributing factor, but its specific role in the correlation between rainfall-runoff and soil erosion remains elusive. Objectives: his study investigated the characteristics of rainfall-runoff and soil erosion resistance in different methods of slash disposals in plantation. Methods: Three methods of slash disposal, namely burning forest (BF), moving away (MA), and spreading evenly (SE), were established. A field simulation experiment of rainfall was conducted, and path analysis was used. Results: The findings revealed that the water holding, infiltrating properties and the time the rainfall-runoff generated of SE were increased by approximately 10∼20 %, 100 %, and 80 %, respectively, compared with BF and MA. Water loss, soil loss and nutrient loss were significantly reduced by 62.23 % and 61.56 %, 69.06 % and 49.55 %, and 58.8 % and 65.42 % in SE and BF compared to MA. Path analysis suggested that different from BF and MA, the correlation between soil water properties and rainfall-runoff factors in SE was weakened, simultaneously considering the result that SE had the lower proportions of silt for sediment component (75.31 %), it stabilized the soil structure. Conclusions and prospect: Consequently, SE mitigated the erosion force by reducing rainfall-runoff and enhancing the anti-erosion of soil through improved water properties, making it a viable slash disposal. This work provides a detailed description of the soil erosion characteristics of plantation, including water, soil, and nutrient losses caused by rainfall-runoff, as well as the soil anti-erosion due to different slash disposals. These findings offer valuable insights for the management of high-intensity Eucalyptus grandis × urophylla plantations.

The impact of frailty on clinical outcomes of older patients undergoing enhanced recovery after lumbar fusion surgery: A prospective cohort study.

BACKGROUND: Frailty is recognized as a surrogate for physiological age and has been established as a valid and independent predictor of postoperative morbidity, mortality, and complications. ERAS can enhance surgical safety by minimizing stress responses in frail patients, enabling surgeons to discharge patients earlier. However, the question of whether and to what extent the frailty impacts the post-ERAS outcomes in older patients remains. MATERIALS AND METHODS: An evidence-based ERAS program was implemented in our center from January 2019. This is a prospective cohort study of patients aged ≥75 years who underwent open transforaminal lumbar interbody fusion (TLIF) for degenerative spine disease from April 2019 to October 2021. Frailty was assessed with the Fried frailty scale (FP scale), and patients were categorized as non/prefrail (FP 0-2) or frail (FP ≥ 3). The preoperative variables, operative data, postoperative outcomes and follow-up information were compared between the two groups. Univariate and multivariate logistic regression analyses were used to identify risk factors for 90-day major complications and prolonged length of hospital stay (LOS) after surgery. RESULTS: A total of 245 patients (age of 79.8 ± 3.4 yr) who had a preoperative FP score recorded and underwent scheduled TLIF surgery were included in the final analysis. Comparisons between non-frail and prefrail/frail patients revealed no significant difference in age, sex, and surgery-related variables. Even after adjusting for multiple comparisons, the association between Fried frailty and ADL-dependency, IADL-dependency, and malnutrition remained significant. Preoperative frailty was associated with increased rates of postoperative adverse events. A higher CCI grade was an independent predictor for 90-day major complications, while Fried frailty and MNA-SF scores <12 were predictive of poor postoperative recovery. CONCLUSION: Frail older patients had more adverse post-ERAS outcomes after TLIF compared to non/prefrail older patients. Continued research and multidisciplinary collaboration will be essential to refine and optimize protocols for surgical care in frail older adults.

Path to pollution and carbon reduction synergy from the perspective of the digital economy: Fresh evidence from 292 prefecture-level cities in China.

The digital economy is a crucial focus for realizing the transformation of old and new kinetic energy in China. It is widely integrated with various fields of the economy and society, constantly providing a new dynamic mechanism with synergetic control of environmental pollution and carbon emissions (SCEPCE). Based on panel data from 292 prefecture-level cities in China from 2011 to 2021, this study discusses the spatial effects and mechanisms of the digital economy on the coordinated control of pollutants and carbon emissions. The study found that: (1) The digital economy has direct and indirect influences on the coordinated control of pollutants and carbon emissions. The digital economy can drive reductions in pollutants and carbon dioxide emissions by upgrading industrial structures and transforming energy structures. (2) Green innovation plays an active regulatory role in the digital economy and structural optimization, particularly in the context of SCEPCE. This interference helps mitigate the impact of the digital economy on pollution and carbon emissions. (3) The digital economy has a significant spatial spillover effect on the coordinated control of pollutants and carbon emissions. (4) The influence mechanism of the digital economy on pollution reduction and carbon reduction synergy exhibits geographical heterogeneity, resource endowment heterogeneity. To enhance the synergy of pollution reduction and carbon reduction, it is essential to bolster support and optimise the digital economy at various levels. This includes reinforcing regional balance, considering spatial spillover effects, and enhancing the leading role of developed cities in the region.

MicroRNAs regulate the vicious cycle of vascular calcification-osteoporosis in postmenopausal women.

Menopause is a normal physiological process accompanied by changes in various physiological states. The incidence of vascular calcification (VC) increases each year after menopause and is closely related to osteoporosis (OP). Although many studies have investigated the links between VC and OP, the interaction mechanism of the two under conditions of estrogen loss remains unclear. MicroRNAs (miRNAs), which are involved in epigenetic modification, play a critical role in estrogen-mediated mineralization. In the past several decades, miRNAs have been identified as biomarkers or therapeutic targets in diseases. Thus, we hypothesize that these small molecules can provide new diagnostic and therapeutic approaches. In this review, we summarize the close interactions between VC and OP and the role of miRNAs in their interplay.

Identifying the miRNA-gene networks contributes to exploring paravertebral muscle degeneration's underlying pathogenesis and therapy strategy.

Low back pain (LBP) is a worldwide problem with public health. Paravertebral muscle degeneration (PMD) is believed to be associated with LBP. Increasing evidence has demonstrated that microRNA (miRNA)-mRNA signaling networks have been implicated in the pathophysiology of diseases. Research suggests that cell death, oxidative stress, inflammatory and immune response, and extracellular matrix (ECM) metabolism are the pathogenesis of PMD; however, the miRNA-mRNA mediated the pathological process of PMD remains elusive. RNA sequencing (RNA-seq) and single cell RNA-seq (scRNA-seq) are invaluable tools for uncovering the functional biology underlying these miRNA and gene expression changes. Using scRNA-seq, we show that multiple immunocytes are presented during PMD, revealing that they may have been implicated with PMD. Additionally, using RNA-seq, we identified 76 differentially expressed genes (DEGs) and 106 differentially expressed miRNAs (DEMs), among which IL-24 and CCDC63 were the top upregulated and downregulated genes in PMD. Comprehensive bioinformatics analyses, including Venn diagrams, differential expression, functional enrichment, and protein-protein interaction analysis, were then conducted to identify six ferroptosis-related DEGs, two oxidative stress-related DEGs, eleven immunity-related DEGs, five ECM-related DEGs, among which AKR1C2/AKR1C3/SIRT1/ALB/IL-24 belong to inflammatory genes. Furthermore, 67 DEMs were predicted to be upstream miRNAs of 25 key DEGs by merging RNA-seq, TargetScan, and mirDIP databases. Finally, a miRNA-gene network was constructed using Cytoscape software and an alluvial plot. ROC curve analysis unveiled multiple key DEGs with the high clinical diagnostic value, providing novel approaches for diagnosing and treating PMD diseases.

Developmental origins shape the paediatric cancer genome.

In the past two decades, technological advances have brought unprecedented insights into the paediatric cancer genome revealing characteristics distinct from those of adult cancer. Originating from developing tissues, paediatric cancers generally have low mutation burden and are driven by variants that disrupt the transcriptional activity, chromatin state, non-coding cis-regulatory regions and other biological functions. Within each tumour, there are multiple populations of cells with varying states, and the lineages of some can be tracked to their fetal origins. Genome-wide genetic screening has identified vulnerabilities associated with both the cell of origin and transcription deregulation in paediatric cancer, which have become a valuable resource for designing new therapeutic approaches including those for small molecules, immunotherapy and targeted protein degradation. In this Review, we present recent findings on these facets of paediatric cancer from a pan-cancer perspective and provide an outlook on future investigations.

Chronic kidney disease with malignant peripheral nerve sheath tumor of the ureter: a case report.

Malignant peripheral nerve sheath tumors (MPNSTs) are a complex group of malignant tumors originating from nerve cells or benign peripheral nerve sheath tumors and are commonly found in major plexus/nerve root sites such as the limbs, head, and neck. Malignant peripheral nerve sheath tumors originating in the ureter are extremely rare. Herein, we report the case of a 63-year-old patient with a malignant peripheral nerve sheath tumor of the right ureter who underwent laparoscopic radical resection of the right kidney and ureter. The patient also had stage 5 chronic kidney disease (CKD). Therefore, chemotherapy and radiotherapy were not considered. No tumor recurrence was observed during the follow-up period.

Metabolic Engineering of Corynebacterium glutamicum for Highly Efficient Production of Ectoine.

Ectoine is a compatible solute that functions as a cell protector from various stresses, protecting cells and stabilizing biomolecules, and is widely used in medicine, cosmetics, and biotechnology. Microbial fermentation has been widely used for the large-scale production of ectoine, and a number of fermentation strategies have been developed to increase the ectoine yield, reduce production costs, and simplify the production process. Here, Corynebacterium glutamicum was engineered for ectoine production by heterologous expression of the ectoine biosynthesis operon ectBAC gene from Halomonas elongata, and a series of genetic modifications were implemented. This included introducing the de3 gene from Escherichia coli BL21 (DE3) to express the T7 promoter, eliminating the lysine transporter protein lysE to limit lysine production, and performing a targeted mutation lysCS301Y on aspartate kinase to alleviate feedback inhibition of lysine. The new engineered strain Ect10 obtained an ectoine titer of 115.87 g/L in an optimized fed-batch fermentation, representing the highest ectoine production level in C. glutamicum and achieving the efficient production of ectoine in a low-salt environment.

Centrosymmetry-Breaking Morphotropic Phase Boundary: A Pathway to Highly Sensitive and Strong Pressure-Responsive Nonlinear Optical Switches.

The quest for high-performance piezoelectric materials has been synonymous with the pursuit of the morphotropic phase boundary (MPB), yet the full potential of MPBs remains largely untapped outside of the realm of ferroelectrics. In this study, we reveal a new class of MPB by creating continuous molecular-based solid solutions between centro- and noncentrosymmetric compounds, exemplified by (tert-butylammonium)1-x(tert-amylammonium)xFeCl4 (0 ≤ x ≤ 1), where the MPB is formed due to disorder of molecular cations. Near the MPB, we discovered an exceptionally sensitive nonlinear optical material in the centrosymmetric phase, capable of activation at pressures as low as 0.12-0.27 GPa, and producing tunable second-harmonic generation (SHG) signals from zero to 18.8 times that of KH2PO4 (KDP). Meanwhile, synchrotron diffraction experiments have unveiled a third competing phase (P212121) appearing at low pressure, forming a triple-phase point near the MPB, thereby providing insight into the mechanism underpinning the nonlinear optical (NLO) switch behavior. These findings highlight the opportunity to harness exceptional physical properties in symmetry-breaking solid solution systems by strategically designing novel MPBs.

JNK signaling mediates acute rejection via activating autophagy of CD8+ T cells after liver transplantation in rats.

Background: Acute rejection (AR) after liver transplantation (LT) remains an important factor affecting the prognosis of patients. CD8+ T cells are considered to be important regulatory T lymphocytes involved in AR after LT. Our previous study confirmed that autophagy mediated AR by promoting activation and proliferation of CD8+ T cells. However, the underlying mechanisms regulating autophagy in CD8+ T cells during AR remain unclear. Methods: Human liver biopsy specimens of AR after orthotopic LT were collected to assess the relationship between JNK and CD8+ T cells autophagy. The effect of JNK inhibition on CD8+ T cells autophagy and its role in AR were further examined in rats. Besides, the underlying mechanisms how JNK regulated the autophagy of CD8+ T cells were further explored. Results: The expression of JNK is positive correlated with the autophagy level of CD8+ T cells in AR patients. And similar findings were obtained in rats after LT. Further, JNK inhibitor remarkably inhibited the autophagy of CD8+ T cells in rat LT recipients. In addition, administration of JNK inhibitor significantly attenuated AR injury by promoting the apoptosis and downregulating the function of CD8+ T cells. Mechanistically, JNK may activate the autophagy of CD8+ T cells through upregulating BECN1 by inhibiting the formation of Bcl-2/BECN1 complex. Conclusion: JNK signaling promoted CD8+ T cells autophagy to mediate AR after LT, providing a theoretical basis for finding new drug targets for the prevention and treatment of AR after LT.

Surgical treatment of Roussouly type 1 with realigning Roussouly spinal shape and improving SRS-Schwab modifier: effect on minimal clinically important difference.

PURPOSE: To evaluate outcomes of choosing different Roussouly shapes and improving in Schwab modifiers for surgical Roussouly type 1 patients. METHODS: Baseline (BL) and 2-year (2Y) clinical data of adult spinal deformity (ASD) patients presenting with Roussouly type 1 sagittal spinal alignment were isolated in the single-center spine database. Patients were grouped into Roussouly type 1, 2 and 3 with anteverted pelvis (3a) postoperatively. Schwab modifiers at BL and 2Y were categorized as follows: no deformity (0), moderate deformity (+), and severe deformity (++) for pelvic tilt (PT), sagittal vertical axis (SVA), and pelvic incidence and lumbar lordosis mismatch (PI-LL). Improvement in SRS-Schwab was defined as a decrease in the severity of any modifier at 2Y. RESULTS: A total of 96 patients (69.9 years, 72.9% female, 25.2 kg/m2) were included. At 2Y, there were 34 type 1 backs, 60 type 2 backs and only 2 type 3a. Type 1 and type 2 did not differ in rates of reaching 2Y minimal clinically important difference (MCID) for health-related quality of life (HRQOL) scores (all P > 0.05). Two patients who presented with type 3a had poor HRQOL scores. Analysis of Schwab modifiers showed that 41.7% of patients improved in SVA, 45.8% in PI-LL, and 36.5% in PT. At 2Y, patients who improved in SRS-Schwab PT and SVA had lower Oswestry disability index (ODI) scores and significantly more of them reached MCID for ODI (all P < 0.001). Patients who improved in SRS-Schwab SVA and PI-LL had more changes of VAS Back and Short Form-36 (SF-36) outcomes questionnaire physical component summary (SF-36 PCS), and significantly more reached MCID (all P < 0.001). By 2Y, type 2 patients who improved in SRS-Schwab grades reached MCID for VAS back and ODI at the highest rate (P = 0.003, P = 0.001, respectively), and type 1 patients who improved in SRS-Schwab grades reached MCID for SF-36 PCS at the highest rate (P < 0.001). CONCLUSION: For ASD patients classified as Roussouly type 1, postoperative improvement in SRS-Schwab grades reflected superior patient-reported outcomes while type 1 and type 2 did not differ in clinical outcomes at 2Y. However, development of type 3a should be avoided at the risk of poor functional outcomes. Utilizing both classification systems in surgical decision-making can optimize postoperative outcomes.

Spatial distribution characteristics and pollution evaluation of soil heavy metals in Wulongdong National Forest Park.

To scrutinize the spatial distribution attributes of soil heavy metal content and discern its pollution status within the expanse of Wulongdong National Forest Park, a meticulous investigation is imperative. Three altitude gradients of 900, 1000, and 1069 m were selected on the shady and sunny slopes of Wulongdong National Forest Park, and a total of 300 soil sample points were collected. Soil samples were collected in layers, and the contents of seven soil heavy metal elements, Cr, Cd, Hg, Ni, Se, As, and Pb, were measured. With regard to the national soil element background values, the single factor index method, Nemerow index method, and pollution load index were employed to undertake a thorough assessment of soil heavy metal pollution. (1) The contents of heavy metal elements Cr, Se, As, and Pb in the 0-20 cm soil layer of Wulongdong National Forest Park are lower than the national soil element background value and the Henan soil element background value; the Cd and Hg contents exceed the national soil element background value. The value and Henan soil element background value are 2.2 times and 2.92 times the national soil element background value, and 2.75 times and 9.5 times the Henan soil element background value respectively; Ni content is lower than the Henan soil element background value, but higher than the national soil element background value. The background value is 1.03 times its content. The coefficients of variation of the contents of seven heavy metal elements are all greater than 50%, among which Hg shows extreme variation, and the remaining six are highly variable. (2) In the same soil layer, the Cr and As contents are lower on sunny slopes than on shady slopes, and the contents of Pb, Ni, and Hg are generally higher on sunny slopes than on shady slopes. On sunny slopes, the contents of As, Cd, and Hg decrease with increasing altitude, and the Se content increases with increasing altitude; while on shady slopes, the contents of Cr, Se, and As decrease with increasing altitude, and Pb and Hg content increase with the increase of altitude; the content of heavy metal element As increases with the deepening of the soil layer on shady slopes, and the Hg content decreases with the deepening of the soil layer on sunny slopes. The contents of other heavy metal elements have no obvious regularity among different slope directions, altitudes and soil layers. (3) The single factor index evaluation results show that in the 0 ~ 20c soil layer and on the sunny slope, Hg is heavily polluted, Cd is moderately polluted, Ni is lightly polluted, and Cr, Se, As, and Pb are all non-polluted; On the shady slope, Cd and Hg are moderately polluted, and the other five heavy metal elements are in a non-polluting state. (4) The Nemerow index method evaluation results show that in the 0 ~ 20 cm soil layer, the soil on sunny slopes is significantly more polluted by heavy metals than on shady slopes, and the main pollutants are Ni, Cd and Hg. (5) In the 0 ~ 20 cm soil layer of Wulongdong National Forest Park, the three heavy metal elements Ni, Cd and Hg have reached pollution levels, of which Ni is slightly polluted, Cd and Hg are moderately or above polluted; the sunny slope soil is slightly polluted. Heavy metal pollution, no heavy metal pollution on shady slopes.

Diagnostic performance of PIVKA-II in identifying recurrent hepatocellular carcinoma following curative resection: a retrospective cohort study.

Protein induced by vitamin K absence or antagonist II (PIVKA-II) plays a critical role in the diagnosis of hepatocellular carcinoma (HCC), however, studies on its efficacy in diagnosing recurrent HCC were rarely found. A multicenter, retrospective, and observational study was conducted. During the overall follow-up of 5 years, HCC patients who had curative resection were monitored every 3 months in the first year post-surgery and every 6 months thereafter if no recurrence occurred. Tumor markers were collected at the diagnosis of recurrence for those with recurrence and at the last follow-up for those without recurrence. The median serum levels of PIVKA-II and AFP in the recurrence group were significantly higher than those in the non-recurrence group (PIVKA-II: 84.62 vs. 18.76 mAU/ml, p < 0.001; AFP: 4.90 vs. 3.00 ng/ml, p < 0.001) and there is a significant correlation between PIVKA-II and AFP (R = 0.901, p < 0.001). PIVKA-II showed better accuracy than AFP in the diagnosis of overall recurrent HCC (AUC: 0.883 vs. 0.672; p < 0.0001), but also in patients with negative PIVKA-II before curative resection (AUC: 0.878 vs. 0.680, p = 0.001). Clinician should pay more attention to serum PIVKA-II values when following patients after curative HCC resection to detect early recurrence.Clinical trial registration: ChiCTR2300070874.

Radiographic and surgery-related predictive factors for increased segmental lumbar lordosis following lumbar fusion surgery in patients with degenerative lumbar spondylolisthesis.

OBJECTIVE: This study aimed to evaluate preoperative (pre-op) radiographic characteristics and specific surgical interventions in patients with degenerative lumbar spondylolisthesis (DLS) who underwent lumbar fusion surgery (LFS), with a focus on analyzing predictors of postoperative restoration of segmental lumbar lordosis (SLL). METHODS: A retrospective review at a single center identified consecutive single-level DLS patients who underwent LFS between 2016 and 2022. Radiographic measures included disc angle (DA), SLL, lumbar lordosis (LL), anterior/posterior disc height (ADH/PDH), spondylolisthesis percentage (SP), intervertebral disc degeneration, and paraspinal muscle quality. Surgery-related measures included cage position, screw insertion depth, spondylolisthesis reduction rate, and disc height restoration rate. A change in SLL ≥ 4° indicated increased segmental lumbar lordosis (ISLL), and unincreased segmental lumbar lordosis (UISLL) < 4°. Propensity score matching was employed for a 1:1 match between ISLL and UISLL patients based on age, gender, body mass index, smoking status, and osteoporosis condition. RESULTS: A total of 192 patients with an average follow-up of 20.9 months were enrolled. Compared to UISLL patients, ISLL patients had significantly lower pre-op DA (6.78° vs. 11.84°), SLL (10.73° vs. 18.24°), LL (42.59° vs. 45.75°), and ADH (10.09 mm vs. 12.21 mm) (all, P < 0.05). ISLL patients were predisposed to more severe intervertebral disc degeneration (P = 0.047) and higher SP (21.30% vs. 19.39%, P = 0.019). The cage was positioned more anteriorly in ISLL patients (67.00% vs. 60.08%, P = 0.000), with more extensive reduction of spondylolisthesis (- 73.70% vs. - 56.16%, P = 0.000) and higher restoration of ADH (33.34% vs. 8.11%, P = 0.000). Multivariate regression showed that lower pre-op SLL (OR 0.750, P = 0.000), more anterior cage position (OR 1.269, P = 0.000), and a greater spondylolisthesis reduction rate (OR 0.965, P = 0.000) significantly impacted SLL restoration. CONCLUSIONS: Pre-op SLL, cage position, and spondylolisthesis reduction rate were identified as significant predictors of SLL restoration after LFS for DLS. Surgeons are advised to meticulously select patients based on pre-op SLL and strive to position the cage more anteriorly while minimizing spondylolisthesis to maximize SLL restoration.

The association between inflammatory biomarkers and low back disorder: a systematic review and meta-analysis.

INTRODUCTION: Low back disorder (LBD) is a major cause of disability worldwide. Inflammation results in proliferation of cytokines or consequent degradation products (collectively known as inflammatory biomarkers) that activate pain pathways which can result in non-specific LBD. This systematic review and meta-analysis aim to evaluate the relationship between inflammatory biomarkers and clinical outcomes in patients with LBD. METHODS: The PRISMA guideline was followed for the systematic reivew. Three online databases were searched. Four RCTs and sixteen observational studies with 1142 LBD patients were analysed. The primary outcomes were back and leg pain scores, back-specific disability scores and expression of inflammatory biomarkers. Standardized mean difference (SMD) and their 95% confidence intervals (CI) were evaluated. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to summarize the strength of evidence. RESULTS: Four RCTs and sixteen observational studies were included in the analysis of 1142 patients with LBD. There was a statistically significant reduction in back pain score and IL-1 beta and increase in the expression of CTX-1 and IL-10 levels post treatment. There was a significant relationship between increase in the expression of MCP- and reduction in the expression of hsCRP with increase in back pain. Significant relationship was also observed between increase in the expression of MCP-1 and reduction in the expression of IL-6 with increase in leg pain. Increase in the expression of IL-8 and reduction in the expression of hsCRP was also associated with increased disability score. CONCLUSION: Inflammatory biomarkers play a significant role in the pathogenesis of LBD. CTX-1, IL-10 and IL-1 beta may be responsible for the decrease in back pain scores post treatment. There is a relationship between MCP-1, IL-6, IL-8 and hsCRP with clinical and functional assessments for LBD. Further studies will improve understanding of the pathogenesis of LBD and aid in targeted management strategies.

Imaging predictors of progression of lumbar spondylolysis to spondylolisthesis: a systematic review.

BACKGROUND CONTEXT: Isthmic spondylolisthesis (IS) is defined as the anterior translation of one lumbar vertebra relative to the next caudal segment as a result of a unilateral or bilateral fracture of the pars interarticularis. These fractures are interchangeably known as "pars defects" or "spondylolysis." Many risk factors have been proposed to explain the progression of a spondylolytic defect to IS, however, none are validated. PURPOSE: This systematic review provides an overview of various radiological and imaging parameters that can help predict the risk of progression of a spondylolytic defect into IS. STUDY DESIGN: Systematic review. METHODS: Medline, Embase and Cochrane online database were searched. The various correlations between imaging features with observed spondylolisthesis prevalence or severity or spondylolysis rates of spondylolisthesis were evaluated to provide a list of imaging risk factors to predict IS. Significance of the correlations in the original article was recorded to enable comparison of the collected evidence of separate image features. RESULTS: All searches combined generated a total of 431 results of which 26 articles were included into this study. Of the 22 potential risk factors identified, 5 were found to be statistically insignificant, 8 were found to be significant and 9 had mixed results. The following features were found to be significant risk factors in at least on study: disc degeneration, transverse process width, pelvic incidence, pelvic tilt, sacral slope, lumbar lordosis, lumbar index, thoracic kyphosis, facet joint angle above the level of defect, facet joint degeneration, facet tropism, multifidus size, lateral erector spinae size, mesenteric fat thickness, subcutaneous fat thickness and soft tissue calcification. CONCLUSION: Our research suggests that only disc degeneration had moderately strong evidence with consistent significant associations with development of IS in patients with spondylolysis. Transverse process width, pelvic incidence, pelvic tilt, sacral slope, lumbar lordosis, lumbar index, thoracic kyphosis, facet joint angle above the level of defect, facet joint degeneration, facet tropism, multifidus size, lateral erector spinae size, mesenteric fat thickness, subcutaneous fat thickness and soft tissue calcification had some evidence. All other radiological factors had weak evidence. The results of this study can be used to improve early clinical decision making for patients with spondylolysis.

Correcting Hardening Artifacts of Aero-Engine Blades with an Iterative Linear Fitting Technique Framework.

Aero engines are the key power source for aerospace vehicles. Cermet turbine blades are the guarantee for the new-generation fighters to improve aero-engine overall performance. X-ray non-destructive reconstruction can obtain the internal structure and morphology of cermet turbine blades. However, the beam hardening effect causes artifacts in objects and affects the reconstruction quality, which is an issue that needs to be solved urgently. This study proposes a hardening-correction framework for industrial computed tomography (ICT) images based on iterative linear fitting. First, an iterative binarization was performed to improve the penetration length accuracy of the forward projection. Then, the proposed linear fitting technology combined with the Hermite function model is derived and analyzed to obtain suitable parameters of blade data. Finally, the fitting curves of the blade data, using the proposed method and the traditional polynomial fitting method, were analyzed and compared and were used to correct the engine turbine blade projection data to reconstruct different groups of tomographic images. Different groups of tomographic images were analyzed using three quantitative image quality evaluation indicators. The results show that the root-mean-square error (RMSE) of the tomographic image obtained by the proposed framework is 0.0133, which is lower than that of the compared method. The peak signal-to-noise ratio (PSNR) is 37.7050 dB and the feature structural similarity (FSIM) is 0.9881, which are both higher than that of the compared method. The proposed method improves the hardening-artifact-correction capability and can obtain higher-quality images, which provides new ideas for the development of imaging and detection of new-generation aero-engine turbine blades.