Design and first-round commissioning result of the SASE beamline at the Shanghai Soft X-ray FEL facility.

The Shanghai Soft X-ray Free-Electron Laser (SXFEL) is the first X-ray free-electron laser facility in China. The SASE beamline, which consists of a pink-beam branch and a mono-beam branch, is one of the two beamlines in the Phase-I construction. The pink-beam branch opened for users in 2023 after successful first-round beamline commissioning. In this paper, the design of the beamline is presented and the performance of the pink-beam branch is reported. The measured energy-resolving power of the online spectrometer is over 6000 @ 400 eV. The focusing spot size of the pink beam is less than 3 µm in both the horizontal and vertical at the endstation.

Transforming a Toxic Non-Ionizable Drug into an Efficacious Liposome via Ionizable Prodrug and Remote Loading Strategies against Malignant Breast Tumors.

Liposomes (lipos), one of the most successful nanotherapeutics in the clinic, have made a rapid advance over the past few years. However, still, several challenges exist for lipos for clinical practice, such as low drug loading and premature drug leakage during in vivo circulation. Paclitaxel (PTX), a commonly used first-line drug for cancer chemotherapy, was chosen as the model drug. Due to its non-ionizable and water-insoluble characteristics, the drug-loading efficiency of the marketable PTX lipos, Lipusu, is only 6.76%. Herein, we designed an ionizable PTX prodrug (PTXP) by modifying phenylboronic acid on the C2' hydroxyl group of PTX for the remote loading of liposomal formulations through the pH gradient method. Compared with Lipusu, PTXP lipos displayed a 34% higher loading efficiency and an encapsulation efficiency of approximately 95%. A series of in vitro/vivo experiments indicated that PTXP lipos possess colloidal stability, prolonged blood circulation, high tumor site accumulation, potent anti-tumor effects, and safety. A combination of ionizable prodrugs and remote loading has proved to be an effective and simple strategy to achieve high liposomal encapsulation efficiency of poorly soluble non-ionizable drugs for clinical application.

CSMOT: Make One-Shot Multi-Object Tracking in Crowded Scenes Great Again.

The current popular one-shot multi-object tracking (MOT) algorithms are dominated by the joint detection and embedding paradigm, which have high inference speeds and accuracy, but their tracking performance is unstable in crowded scenes. Not only does the detection branch have difficulty in obtaining the accurate object position, but the ambiguous appearance of features extracted by the re-identification (re-ID) branch also leads to identity switches. Focusing on the above problems, this paper proposes a more robust MOT algorithm, named CSMOT, based on FairMOT. First, on the basis of the encoder-decoder network, a coordinate attention module is designed to enhance the information interaction between channels (horizontal and vertical coordinates), which improves its object-detection abilities. Then, an angle-center loss that effectively maximizes intra-class similarity is proposed to optimize the re-ID branch, and the extracted re-ID features are made more discriminative. We further redesign the re-ID feature dimension to balance the detection and re-ID tasks. Finally, a simple and effective data association mechanism is introduced, which associates each detection instead of just the high-score detections during the tracking process. The experimental results show that our one-shot MOT algorithm achieves excellent tracking performance on multiple public datasets and can be effectively applied to crowded scenes. In particular, CSMOT decreases the number of ID switches by 11.8% and 33.8% on the MOT16 and MOT17 test datasets, respectively, compared to the baseline.

The stability of repaired meniscal root can affect postoperative cartilage status following medial meniscus posterior root repair.

BACKGROUND: Transtibial pullout repair yields beneficial clinical outcomes in patients with medial meniscus (MM) posterior root tear. However, the relationship between repaired meniscal root healing status and postoperative clinical outcomes remains unclear. We aimed to evaluate changes in articular cartilage damage and clinical scores after pullout repair using two simple stitches (TSS). METHODS: Thirty-three patients who underwent pullout repair using TSS were assessed. Healing status was assessed by a semi-quantitative second-look arthroscopic scoring system comprising three evaluation criteria (width of bridging tissues, stability of the repaired root, and synovial coverage), 1 year postoperatively. MM medial extrusion (MMME) and cartilage damage were assessed preoperatively and 1 year postoperatively. The medial compartment was divided into 8 zones (A-H) for comparison of preoperative and 1-year postoperative cartilage damage. Clinical outcomes were evaluated using the Knee Injury and Osteoarthritis Outcome score, Lysholm score, International Knee Documentation Committee scores, and visual analogue scale pain score. RESULTS: Although cartilage damage did not aggravate significantly in most medial compartment areas, MMME progressed at 1 year postoperatively. No statistical differences were observed in cartilage damage between the central-to-medial area of the medial femoral condyle and the medial tibial plateau area at 1 year postoperatively. Regarding semi-quantitative healing scores, the stability score was significantly correlated with the International Cartilage Repair Society grade at 1 year postoperatively. All 1-year and 2-year clinical scores significantly improved compared with the preoperative scores. CONCLUSION: Regarding TSS repair, stability of repaired meniscal root negatively correlated with cartilage damage in the medial compartment loading area. All 1-year and 2-year clinical scores significantly improved than those of the preoperative scores. Achieving MM stability is crucial for suppressing cartilage degeneration. LEVEL OF EVIDENCE: IV case series study.

Concomitant posterior anchoring further reduces posterior meniscal extrusion during pullout repair of medial meniscus posterior root tears: a retrospective study.

PURPOSE: Transtibial pullout repair improves the clinical outcomes of medial meniscus (MM) posterior root tears (PRTs); however, reducing MM extrusion remains challenging. Thus, the purpose of this study was to examine the role of additional posterior anchoring (PA) during pullout repair in reducing the severity of MM extrusion compared to pullout repair alone. METHODS: Patients who underwent pullout repair with two-cinch stitches (TCS) only or TCS combined with PA (TCS-PA)-deployment of an additional suture anchor in the posteromedial corner of MM-were included retrospectively. MM medial and posterior extrusion (MMME and MMPE), MM extrusion and remaining volume (MMEV and MMRV), and corresponding ratios were evaluated pre-operatively and three months post-operatively using a three-dimensional meniscal model at 10° and 90° of knee flexion and compared within and between groups. RESULTS: A total of 15 and 16 patients treated with TCS and TCS-PA, respectively, were enrolled. At 90° knee flexion, both techniques significantly reduced MMPE (TCS: 4.2 ± 0.7 mm to 3.5 ± 0.6 mm, p < 0.05; TCS-PA: 3.7 ± 0.8 mm to 2.8 ± 0.7 mm, p < 0.05) at three months post-operatively. TCS-PA reduced MMPE more significantly than TCS alone (p < 0.05). Only TCS-PA significantly improved the MMEV and MMRV ratios (39.6 ± 8.9% to 28.1 ± 6.0%, p < 0.05 and 60.4 ± 8.9% to 71.9 ± 6.0%, p < 0.05, respectively). Significance was not found in all other comparisons. CONCLUSIONS: Both techniques improved MMPE at knee flexion at the three month follow-up, with TCS-PA providing significantly superior results. Our findings support the evidence that the application of PA may be an effective surgical option for alleviating persistent MMPE.

Density Functional Theory Study of CO2 Hydrogenation on Transition-Metal-Doped Cu(211) Surfaces.

The massive emission of CO2 has caused a series of environmental problems, including global warming, which exacerbates natural disasters and human health. Cu-based catalysts have shown great activity in the reduction of CO2, but the mechanism of CO2 activation remains ambiguous. In this work, we performed density functional theory (DFT) calculations to investigate the hydrogenation of CO2 on Cu(211)-Rh, Cu(211)-Ni, Cu(211)-Co, and Cu(211)-Ru surfaces. The doping of Rh, Ni, Co, and Ru was found to enhance CO2 hydrogenation to produce COOH. For CO2 hydrogenation to produce HCOO, Ru plays a positive role in promoting CO dissociation, while Rh, Ni, and Co increase the barriers. These results indicate that Ru is the most effective additive for CO2 reduction in Cu-based catalysts. In addition, the doping of Rh, Ni, Co, and Ru alters the electronic properties of Cu, and the activity of Cu-based catalysts was subsequently affected according to differential charge analysis. The analysis of Bader charge shows good predictions for CO2 reduction over Cu-based catalysts. This study provides some fundamental aids for the rational design of efficient and stable CO2-reducing agents to mitigate CO2 emission.

Chilling injury monitoring and intensity identification of dryland maize in Heilongjiang.

BACKGROUND: Accurate and timely access to large-scale crop damage information provides an essential reference for responding to agricultural disaster prevention and mitigation needs and ensuring food production security. The present study aimed to reveal the new characteristics of low-temperature cold damage to maize in the context of climate warming. Heilongjiang, one of the provinces with the highest latitude, the most significant climate change and the largest maize production in China, was taken as the study area. We combined meteorological stations and MODIS remote sensing data to spatially identify the occurrence and intensity of cold damage to maize based on the growing season temperature distance level index, as well as to assess the extent of cold damage. RESULTS: The main findings are: (i) The frequency and intensity range of cold damage in the growing season (May to September) in Heilongjiang Province from 1991 to 2020 against climate warming showed a decreasing trend. The average temperature from 1991 to 2000 was 17.777 °C, with seven occurrences of maize cold damage years, of which 5 years comprised widespread cold damage and 2 years comprised regional cold damage. The average temperature from 2000 to 2010 was 18.137 °C, with cold damage three times, of which 2 years comprised regional cold damage and 1 year comprised widespread cold damage. The average temperature from 2010 to 2020 was 18.130 °C, with one maize cold damage year occurring, which comprised regional cold damage. The frequency of maize chilling injury decreased significantly from 1991 to 2020, from 0.23 in 1991-2000 to 0.1 in 2000-2010 and, finally, to 0.03 in 2010-2020. (ii) The good consistency between MODIS_LST data and temperature data from meteorological stations suggests that MODIS_LST data can be used to build a temperature remote sensing estimation model for spatially extensive cold damage monitoring and intensity discrimination. (iii) Taking 2009 as an example of a large-scale cold damage year, the spatial discrimination of maize cold damage intensity shows that the spatial distribution of chilling injury intensity has no obvious geographical features. The intensity of cold damage was mainly mild cold damage. According to administrative regions, the scope of chilling injury was the largest in Mudanjiang City, Heihe City, and Jixi City, accounting for 91.56%, 86.25%, and 84.91%, respectively. The areas with the most extensive range of severe chilling injuries were the Great Khingan Mountains region, Heihe City, Mudanjiang City, Yichun City, and Jixi City. CONCLUSION: In the context of climate warming, the frequency and intensity range of maize cold damage showed a decreasing trend from 1991 to 2020 in Heilongjiang Province. The results of cold damage identification based on MODIS_LST data are accurate and can improve the spatial accuracy. The results of the present study provide a reference and guidance for dealing with the occurrence and defence of spatially refined cold damage. © 2023 Society of Chemical Industry.

Comparison of posterior root remnant cells and horn cells of the medial meniscus.

PURPOSE/AIM OF THE STUDY: Previous studies have noted distinctions between medial meniscus posterior root and horn cells. However, the characteristics of root remnant cells have not been explored in detail. The purpose of this study was to evaluate the gene expression levels, proliferation, and resistance to mechanical stress of remnant and horn cells. MATERIALS AND METHODS: Medial meniscus tissue samples were obtained from patients who underwent total or uni-compartmental knee arthroplasty. Cellular morphology, sry-type HMG box 9, type II collagen, and chondromodulin-I gene expression levels were analyzed. Collagen synthesis was assessed by immunofluorescence staining. Proliferation analysis after 4 h-cyclic tensile strain was performed. RESULTS: Horn cells displayed triangular morphology, whereas root remnant cells appeared fibroblast-like. sry-type HMG box 9 mRNA expression levels were similar in both cells, but type II collagen and chondromodulin-I mRNA expressions were observed only in horn cells. The ratio of type II collagen-positive cells in horn cells was about 10-fold higher than that in root remnant cells, whereas the ratio of sry-type HMG box 9-positive cells was similar. A significant increase in proliferation was observed in root remnant cells compared to that in horn cells. Further, under cyclic tensile strain, the survival rate was higher in root remnant cells than in horn cells. CONCLUSIONS: Medial meniscus root remnant cells showed higher proliferation and resistant properties to cyclic tensile strain than horn cells and showed no chondromodulin-I expression. Preserving the medial meniscus posterior root remnant during pullout repair surgery might maintain mechanical stress-resistant tissue and support healing.

Selective Aerobic Oxidation of Csp3-H Bonds Catalyzed by Yeast-Derived Nitrogen, Phosphorus, and Oxygen Codoped Carbon Materials.

Nitrogen, phosphorus, and oxygen codoped carbon catalysts were successfully synthesized using dried yeast powder as a pyrolysis precursor. The yeast-derived heteroatom-doped carbon (yeast@C) catalysts exhibited outstanding performance in the oxidation of Csp3-H bonds to ketones and esters, giving excellent product yields (of up to 98% yield) without organic solvents at low O2 pressure (0.1 MPa). The catalytic oxidation protocol exhibited a broad range of substrates (38 examples) with good functional group tolerance, excellent regioselectivity, and synthetic utility. The yeast-derived heteroatom-doped carbon catalysts showed good reusability and stability after recycling six times without any significant loss of activity. Experimental results and DFT calculations proved the important role of N-oxide (N+-O-) on the surface of yeast@C and a reasonable carbon radical mechanism.

Postoperative external tibial rotation is correlated with inferior meniscal healing following pullout repair of a medial meniscus posterior root tear.

PURPOSE: The purpose of this study was to evaluate the influence of tibial rotation on the postoperative healing status of the medial meniscus (MM) following pullout repair of the MM posterior root tear (MMPRT). METHODS: Ninety-one patients (68 women and 23 men; mean age 63.3 ± 8.8 years) who had undergone transtibial pullout repair of MMPRT were enrolled in the study. The tibial external rotation angle (ERA) in each patient was measured postoperatively using computed tomography in the extended knee position. The meniscal healing status following transtibial pullout repair was assessed by second-look arthroscopy (mean postoperative period 12 months) using a previously published scoring system (range 0-10). The association between the ERA and the meniscal healing score was investigated using univariate linear regression models. The ERA cut-off for improved meniscal healing score (≥ 7) was determined using receiver-operating characteristic analysis. RESULTS: The ERA and the meniscal healing score were significantly associated, confirming that increased ERAs were correlated with worse meniscal healing status (R = - 0.28; P < 0.001). The optimum ERA cut-off value was 0.5°, with a sensitivity of 68% and a specificity of 63%. The mean meniscal healing scores were 7.3 and 6.2 among patients with ERAs < 0.5° and those with ERAs ≥ 0.5°, respectively (P < 0.001). CONCLUSION: This study demonstrated that the ERA was significantly correlated with the postoperative meniscal healing status. Postoperative tibial rotation could be one of the factors affecting postoperative outcomes of pullout repair of MMPRT. Controlling the tibial rotation may possibly improve meniscal healing. LEVEL OF EVIDENCE: III.

Increased cleft width during knee flexion is useful for the diagnosis of medial meniscus posterior root tears.

PURPOSE: This study aimed to evaluate changes in the cleft width, defined as the distance between the lateral edge of the medial tibial plateau and that of the medial meniscus (MM) posterior root, using open magnetic resonance imaging (MRI) in patients with MM posterior root tear (MMPRT). METHODS: This study included 25 patients (20 women and 5 men; mean age: 65.2 years) who were diagnosed with MMPRT and underwent pullout repair. Upon coronal imaging, the cleft width was evaluated at the 10° and 90° flexed knee positions. The difference in the cleft width (defined as the cleft width at 90° minus the cleft width at 10°) was also calculated. Upon sagittal imaging, the MM posterior extrusion (MMPE) at 90° was also evaluated. Separate univariate linear regression models were used to determine the association between the time from injury to MRI and radiographic measurements. RESULTS: The mean cleft width at 10° and 90° was 4.9 ± 2.6 mm and 7.4 ± 3.7 mm, respectively; the mean difference in cleft width was 2.5 ± 1.5 mm, and the mean MMPE at 90° was 3.7 ± 1.3 mm. There was a significant difference in cleft width at 10° and 90° (p < 0.001). The time from injury to MRI was significantly associated with the cleft width at 10° (R = 0.42; p = 0.023), cleft width at 90° (R = 0.59; p = 0.002), the difference in the cleft width (R = 0.62; p = 0.008), and MMPE at 90° (R = 0.53; p = 0.008). CONCLUSION: This study demonstrates that the cleft width is significantly larger during knee flexion than during knee extension. Increased cleft width during knee flexion ("graben" sign) may help diagnose MMPRT, especially in cases where the cleft sign is unclear during knee extension. LEVEL OF EVIDENCE: III.

CTT: CNN Meets Transformer for Tracking.

Siamese networks are one of the most popular directions in the visual object tracking based on deep learning. In Siamese networks, the feature pyramid network (FPN) and the cross-correlation complete feature fusion and the matching of features extracted from the template and search branch, respectively. However, object tracking should focus on the global and contextual dependencies. Hence, we introduce a delicate residual transformer structure which contains a self-attention mechanism called encoder-decoder into our tracker as the part of neck. Under the encoder-decoder structure, the encoder promotes the interaction between the low-level features extracted from the target and search branch by the CNN to obtain global attention information, while the decoder replaces cross-correlation to send global attention information into the head module. We add a spatial and channel attention component in the target branch, which can further improve the accuracy and robustness of our proposed model for a low price. Finally, we detailly evaluate our tracker CTT on GOT-10k, VOT2019, OTB-100, LaSOT, NfS, UAV123 and TrackingNet benchmarks, and our proposed method obtains competitive results with the state-of-the-art algorithms.

Semi-quantitative arthroscopic scoring system is related to clinical outcomes in patients after medial meniscus posterior root repair.

BACKGROUND: Different methods are available to assess the healing status of repaired root for medial meniscus posterior root tears (MMPRT) using second-look arthroscopy. However, few studies are comparing them or validating their usefulness. Therefore, it was hypothesized that the semi-quantitative arthroscopic score might correlate more with 1-year clinical outcomes in patients with MMPRT than the qualitative evaluation. METHODS: Data of 61 patients who underwent MMPRT pullout repair and second-look arthroscopy were retrospectively evaluated. The semi-quantitative arthroscopic scoring system was divided into three evaluation criteria: scores from 0 to 10 points include the width of the bridging tissue, stability of the repaired root, and synovial coverage. The qualitative evaluation was classified into 4 status; complete healing, lax healing, scar tissue healing, and failed healing according to the stability and mobility of the repaired root. Multivariate linear regression analyses were used to identify predictors of 1-year postoperative clinical outcomes, including Knee Injury and Osteoarthritis Outcome, Lysholm, or International Knee Documentation Committee scores. Spearman's correlation analysis was used to analyze the correlation between second-look arthroscopic score/qualitative evaluation and 1-year postoperative clinical outcomes. In addition, the optimal cutoff point of semi-quantitative arthroscopic score was determined by receiver operating characteristic (ROC) curve. The Mann-Whitney U test was used to compare clinical outcomes between patients with semi-quantitative arthroscopic scores ≥8 and scores <8. RESULTS: All clinical scores significantly improved at 1 year postoperatively. A good correlation was observed between the semi-quantitative score and clinical scores, but none between qualitative evaluation and clinical scores. The optimal cutoff point of semi-quantitative second-look arthroscopic score was 8 points. Significantly, better clinical outcomes were observed in patients with semi-quantitative scores ≥8 points. CONCLUSIONS: All 1-year postoperative clinical scores were significantly improved. The semi-quantitative arthroscopic scores correlate more with 1-year clinical outcomes in patients with MMPRT than the qualitative evaluation. LEVEL OF EVIDENCE: IV case series study.

NiCo alloy/C nanocomposites derived from a Ni-doped ZIF-67 for lightweight microwave absorbers.

In this work, we prepared NiCo alloy/C with rhombic dodecahedron structure and superior microwave absorption performance by using ZIF-67 as the raw material. The rhombic dodecahedron NiCo alloy/C was with rough particles on the surface was photographed by field emission scanning electron microscopy. By adjusting the doping amount of Ni and the temperature of pyrolysis, improved the impedance matching of NiCo alloy/C. Specifically, NiCo alloy/C exhibits a minimum reflection loss of -65.48 dB at 13.48 GHz, while the thickness is 1.63 mm. Defects introduced in the Ni doping process and the special rhombic dodecahedral structure can cause multiple loss mechanisms. Therefore, this NiCo alloy/C composite has the potential to be a potential microwave absorber material with lightweight and high microwave absorption properties.

Knee Flexion-induced Translation of Pullout Sutures Used in the Repair of Medial Meniscus Posterior Root Tears.

Medial meniscus posterior root tears (MMPRTs) have recently attracted considerable interest in orthopedics. To date, no in vivo human study has investigated suture translation changes in repaired MMPRTs with different degrees of knee flexion. This study examined suture translation at various degrees of knee flexion in 30 patients undergoing medial meniscus posterior root repair using the modified Mason-Allen suture technique between August 2016 and September 2017. Intraoperatively, sutures were provisionally fixed to an isometric positioner at the tibial site of the desired meniscal attachment, and the suture translation was measured at 0°, 30°, 60°, and 90° of knee flexion. The results showed significant increases in mean suture translation at the knee flexion positions from 0° to 30°, 30° to 60°, and 60° to 90° (p<0.01 for all). Our findings indicate that surgeons should carefully assess the degree of knee flexion at the moment when the meniscus is refixed by surgical sutures.

Histological Analysis of Repaired Tissue after Pullout Repair of a Medial Meniscus Posterior Root Tear.

A 65-year-old man presented with a left medial meniscus (MM) posterior root tear (PRT). Unicompartmental knee arthroplasty was performed 12 months after transtibial pullout repair of the MMPRT. Repaired MM posterior root tissue was subjected to histological analysis. Immunostaining and picrosirius red staining showed sufficient deposition of type I collagen, and hematoxylin-eosin staining using a polarized microscope showed well-aligned fiber orientation in the repaired tissue. The repaired posterior root (post-transtibial pullout repair) showed mature and well-aligned ligament-like tissue. Preserving the MM posterior root remnant to mimic the original posterior root tissue might be useful when performing pullout repair.

Medial meniscus posterior root repair reduces the extruded meniscus volume during knee flexion with favorable clinical outcome.

PURPOSE: The volume of medial meniscus (MM) extrusion at 10° and 90° knee flexions using three-dimensional (3D) magnetic resonance imaging (MRI) and assessed relevant clinical outcomes at 1-year follow-up were evaluated. METHODS: Twenty-four patients who underwent MM posterior root repair were retrospectively reviewed. At 10° and 90° knee flexions, the meniscal extrusion distance and volume were measured using 3D meniscus models constructed by SYNAPSE VINCENT®. The correlation between Knee Injury and Osteoarthritis Outcome Score, Lysholm, International Knee Documentation Committee scores, Tegner activity, and pain visual analog scales and changes in MM extrusion were assessed. RESULTS: No significant differences in the MM medial extrusion were observed between 10° and 90° knee flexions postoperatively. MM posterior extrusion (MMPE) decreased significantly at 10° and 90° knee flexions postoperatively. At 90° knee flexion, the meniscus volume at the intra-tibial surface increased at 3 and 12 months postoperatively. The MM extrusion volume increased slightly at 10° knee flexion; however, the volume decreased significantly at 90° knee flexion postoperatively. The change in MMPE significantly correlated with clinical scores. All 12-month clinical scores were significantly improved compared to preoperative scores. CONCLUSIONS: The progression of meniscus posterior extrusion and reduction of its volume at 90° knee flexion can be suppressed by MM posterior root repair. Postoperative clinical scores correlated with reductions of the posterior extrusion. Regarding clinical relevance, the dynamic stability of the meniscus can be maintained by MM posterior root repair, which is an effective therapeutic method for improving its clinical status. LEVEL OF EVIDENCE: Level IV.

An MRI-based suspension bridge sign can predict an arthroscopically favorable meniscal healing following the medial meniscus posterior root repair.

BACKGROUND: Medial meniscus (MM) posterior root repairs show favorable clinical outcomes in patients with MM posterior root tears (MMPRTs). However, there is no useful magnetic resonance imaging (MRI) finding to determine a functionally good meniscal healing following MM posterior root repairs. We hypothesized that a characteristic postoperative MRI finding can predict a good meniscal healing following pullout repairs. The aim of this study was to investigate a clinical usefulness of several MRI findings for estimating an actual meniscal healing following MMPRT repairs. METHODS: Fifty eight patients who had a posteromedial painful popping of the injured knee and underwent an arthroscopic pullout repair for the MMPRT were included. Arthroscopic meniscal healing was assessed according to the Furumatsu scoring system at 1 year postoperatively. We evaluated postoperative MRI-based meniscal healing using signal intensity, continuity, suspension bridge-like sign of the MM posterior root, and MM medial extrusion on coronal images. Postoperative clinical outcome evaluations were performed at second-look arthroscopy. RESULTS: Twenty three patients showed good arthroscopic healing scores (≥7 points). Thirty five patients had moderate/poor arthroscopic healing scores (<7 points). At 1-year follow-up period, clinical outcome scores were significantly higher in the good healing group than in the moderate/poor healing group. A characteristic meniscal shape, termed "suspension bridge sign", was highly observed in the good meniscal healing group (83%) compared with in the moderate/poor healing group (26%, P < 0.001). High signal intensity and continuity of the MM posterior root and MM medial extrusion showed no differences between both groups. CONCLUSIONS: Our study demonstrated that the MRI-based suspension bridge sign can predict an arthroscopically favorable meniscal healing following the MM posterior root repair. The suspension bridge-like MRI finding of the MM would be a useful indicator to evaluate the actual meniscal healing in patients who underwent pullout repairs for MMPRTs.

High body mass index is a risk factor for unfavorable clinical outcomes after medial meniscus posterior root repair in well-aligned knees.

BACKGROUND: Severe chondral lesions and varus knee alignment are associated with poor outcomes following transtibial pullout repair for medial meniscus posterior root tears and meniscus tear is strongly associated with body mass index. The prognostic factors in well-aligned knees (femorotibial angle < 180°) with mild chondral lesions are unknown. Therefore, we investigated the prognostic factors in these patients. We hypothesized that high body mass index would lead to poor clinical outcomes following pullout repair of medial meniscus posterior root tears. METHODS: We retrospectively reviewed the files of 28 patients who had undergone pullout repair of medial meniscus posterior root tears between October 2016 and December 2017. We recorded the baseline characteristics (age, gender, height, weight, and body mass index) and the time between injury and surgery. We recorded the International Knee Documentation Committee scores, Knee injury and Osteoarthritis Outcome Scores, and pain visual analog scale scores. Using magnetic resonance imaging preoperatively and 1 year after surgery, we measured the medial meniscus body width and absolute and relative medial meniscus extrusion. Pearson correlation and multivariate linear regression analyses were used to assess potential associations between these factors and clinical outcomes. RESULTS: Age positively correlated (coefficient = 0.49, P < 0.01) and body mass index negatively correlated with the postoperative International Knee Documentation Committee score (coefficient = -0.64, P < 0.01). In multivariate linear regression analysis, body mass index was a significant factor leading to poor postoperative International Knee Documentation Committee score (R2 = 0.29, P < 0.05). CONCLUSIONS: Body mass index > 30 kg/m2 is a risk factor for unfavorable clinical outcomes following pullout repair of medial meniscus posterior root tears in well-aligned knees. LEVEL OF EVIDENCE: III, Comparative retrospective study.

Design of an online spectrometer for the diagnosis of free-electron lasers.

A self-amplified spontaneous emission free-electron laser (FEL) is under construction at the Shanghai Soft X-ray Free-Electron Facility. Therefore, it is necessary to develop a suitable diagnostic tool capable of resolving the natural emission band of each FEL pulse. Thus, an online spectrometer with a plane mirror and plane variable-line-spacing grating at grazing incidence to monitor each single FEL pulse during the propagation of FEL radiation has been designed and is presented in this work. The method of ray tracing is used for monitoring incident radiation in order to understand spectral characteristics, and SHADOW, an X-ray optics simulation tool, and SRW, an X-ray optics wavefront tool, are applied to study the resolving power and focusing properties of the grating. The designed resolving power is ∼3 × 104 at 620 eV. Meanwhile, the effect of the actual slope error of mirrors on the ray-tracing results is also discussed. In order to provide further optimization for the choice of grating, a comparison of resolving powers between 2000 lines mm-1 and 3000 lines mm-1 gratings at different energies is analyzed in detail and radiation damage of mirrors as well as parameters such as the first-order diffraction angle ß, the exit-arm length r2, and the tilt angle θ between the focal plane and the diffraction arm are studied and optimized. This work has provided comprehensive designing methods and detailed data for the design of diagnostic spectrometers in soft X-ray FELs and will be favorable to the design of other similar instruments.