Hybrid-Driven Origami Gripper with Variable Stiffness and Finger Length.

Soft grippers due to their highly compliant material and self-adaptive structures attract more attention to safe and versatile grasping tasks compared to traditional rigid grippers. However, those flexible characteristics limit the strength and the manipulation capacity of soft grippers. In this paper, we introduce a hybrid-driven gripper design utilizing origami finger structures, to offer adjustable finger stiffness and variable grasping range. This gripper is actuated via pneumatic and cables, which allows the origami structure to be controlled precisely for contraction and extension, thus achieving different finger lengths and stiffness by adjusting the cable lengths and the input pressure. A kinematic model of the origami finger is further developed, enabling precise control of its bending angle for effective grasping of diverse objects and facilitating in-hand manipulation. Our proposed design method enriches the field of soft grippers, offering a simple yet effective approach to achieve safe, powerful, and highly adaptive grasping and in-hand manipulation capabilities.

Charge density waves in two-dimensional transition metal dichalcogenides.

Charge density wave (CDW is one of the most ubiquitous electronic orders in quantum materials. While the essential ingredients of CDW order have been extensively studied, a comprehensive microscopic understanding is yet to be reached. Recent research efforts on the CDW phenomena in two-dimensional (2D) materials provide a new pathway toward a deeper understanding of its complexity. This review provides an overview of the CDW orders in 2D with atomically thin transition metal dichalcogenides (TMDCs) as the materials platform. We mainly focus on the electronic structure investigations on the epitaxially grown TMDC samples with angle-resolved photoemission spectroscopy and scanning tunneling microscopy/spectroscopy as complementary experimental tools. We discuss the possible origins of the 2D CDW, novel quantum states coexisting with them, and exotic types of charge orders that can only be realized in the 2D limit.

A simple green method for in-situ selective extraction of Li from spent LiFePO4 batteries by synergistic effect of deep-eutectic solvent and ozone.

Efficient and clean extraction lithium (Li) from spent LiFePO4 batteries (LIBs) still remains a challenge. In this paper, a green deep eutectic solvent (DES) based on ethylene glycol (EG) and choline chloride (CC), combined with ozone (O3) from air source, realized highly selective leaching Li from LiFePO4 in situ for the first time. The influence of experimental parameters on Li and Fe leaching efficiencies (ηLi, ηFe) were studied by orthogonal and single-factor tests, and ηLi ≥ 92.2% while ηFe ≤ 1.6% were obtained under the optimal conditions (6 h, 20 g/L, 8EG:1CC, 40 °C). The impurity Fe in the filtrate was completely precipitated as amorphous FePO4·3H2O after heating (150 °C, 0.5 h), achieving a pure Li-solution. The leaching mechanism elucidated that the synergistic effect (acidification, replacement and oxidation reaction) between the DES and O3 determined the phase transition of Li and Fe, promoting the efficient selective extraction of Li and in-situ separation of Fe (FePO4). The average ηLi and ηFe were separately 85.4% and 2.0% after ten cycles of the 8EG:1CC, indicative of its' excellent reusability. Meanwhile, LiCl was recovered from the filtrate. This process avoided the use of strong acid/alkali and discharge of waste water, providing fresh perspectives on the green recovery of spent LiFePO4 batteries.

A novel green deep eutectic solvent for one-step selective separation of valuable metals from spent lithium batteries: Bifunctional effect and mechanism.

This study used a novel green bifunctional deep eutectic solvent (DES) containing ethylene glycol (EG) and tartaric acid (TA) for the efficient and selective recovery of cathode active materials (LiCoO2 and Li3.2Ni2.4Co1.0Mn1.4O8.3) used in lithium-ion batteries through one-step in-situ separation of Li and Co/Ni/Mn. The effects of leaching parameters on the recovery of Li and Co (ηLi and ηCo) from LiCoO2 are discussed, and the optimal reaction conditions are verified, for the first time, using a response surface method. The results demonstrate that under optimal conditions (120 °C, 12 h, EG to TA mole ratio (MEG:TA) of 5:1, and solid to liquid ratio (RS/L) of 20 g/L), the ηLi from LiCoO2 reached 98.34%, and Co was formed as a purple precipitate of cobalt tartrate (CoC4H4O6), which was transformed into a black powder of Co3O4 after calcination. Notably, the ηLi for DES 5 EG:1 TA was maintained at 80% after five cycles, indicating good cyclic stability. When the as-prepared DES was used to leach the spent active material Li3.2Ni2.4Co1.0Mn1.4O8.3, the in-situ selective separation of Li (ηLi = 98.86%) from other valuable elements such as Ni, Mn, and Co, was achieved, indicating the good selective leaching capacity and practical application potential of the DES.

Does Lumbar Interbody Fusion Modality Affect the Occurrence of Complications in an Osteoporotic Spine Under Whole-Body Vibration? A Finite Element Study.

OBJECTIVE: To evaluate the effects of 3 lumbar interbody fusion techniques on the occurrence of complications in an osteoporotic spine under whole-body vibration. METHODS: A previously developed and validated nonlinear finite element model of L1-S1was modified to develop anterior lumbar interbody fusion (ALIF), posterior lumbar interbody fusion (PLIF), and transforaminal lumbar interbody fusion (TLIF) models with osteoporosis. In each model, the lower surface of the sacrum was absolutely fixed, a follower load of 400N was applied through the axis of the lumbar spine, and an axial sinusoidal vertical load of ±40N (5 Hz) was imposed on the superior surface of L1, to perform a transient dynamic analysis. The maximal values of intradiscal pressure, shear stress on annulus substance, disc bulge, facet joint stress, and screw and rod stress, along with their dynamic response curves, were collected. RESULTS: Among these 3 models, the TLIF model generated the greatest screw and rod stress, and the PLIF model generated the greatest cage-bone interface stress. At the L3-L4 level, compared with the other 2 models, the maximal values and dynamic response curves of intradiscal pressure, shear stress of annulus ground substance, and disc bulge were all lower in the ALIF model. However, the facet contact stress at the adjacent segment in the ALIF model was higher than that in the other 2 models. CONCLUSIONS: In an osteoporotic spine under whole-body vibration, TLIF has the highest risk of screw and rod breakage, PLIF has the highest risk of cage subsidence, and ALIF has the lowest risk of upper adjacent disc degeneration, but the highest risk of adjacent facet joint degeneration.

Efficacy and safety of Tuina for chronic nonspecific low back pain: A PRISMA-compliant systematic review and meta-analysis.

OBJECTIVE: Chronic nonspecific low back pain (CNLBP) is a serious medical and social problem resulting in functional decline and decreased work ability. Tuina, a form of manual therapy, has been sparsely used to treat patients with CNLBP. To systematically assess the efficacy and safety of Tuina for patients with CNLBP. METHODS: Multiple English and Chinese literature databases were searched until September 2022 for randomized controlled trials (RCTs) of Tuina in the treatment of CNLBP. The methodological quality was assessed using the Cochrane Collaboration's tool, and certainty of the evidence was determined with the online Grading of Recommendations, Assessment, Development and Evaluation tool. RESULTS: Fifteen RCTs with 1390 patients were included. Tuina demonstrated a significant effect on pain (SMD: -0.82; 95% CI -1.12 to -0.53; P < .001; I2 = 81%) and physical function (SMD: -0.91; 95% CI -1.55 to -0.27; P = .005; I2 = 90%) when compared to control. However, Tuina resulted in no significant improvement for quality of life (QoL) (SMD: 0.58; 95% CI -0.04 to 1.21; P = .07; I2 = 73%;) compared to control. The Grading of Recommendations, Assessment, Development and Evaluation evidence quality was determined to be low level for pain relief, physical function, and QoL measurements. Only six studies reported adverse events; none were serious. CONCLUSION: Tuina might be an effective and safe strategy for treating CNLBP in terms of pain and physical function, but not for QoL. The study results should be interpreted with caution for their low-level evidence. More multicenter, large-scale RCTs with a rigorous design are required to further confirm our findings.

Signatures of the exciton gas phase and its condensation in monolayer 1T-ZrTe2.

The excitonic insulator (EI) is a Bose-Einstein condensation (BEC) of excitons bound by electron-hole interaction in a solid, which could support high-temperature BEC transition. The material realization of EI has been challenged by the difficulty of distinguishing it from a conventional charge density wave (CDW) state. In the BEC limit, the preformed exciton gas phase is a hallmark to distinguish EI from conventional CDW, yet direct experimental evidence has been lacking. Here we report a distinct correlated phase beyond the 2×2 CDW ground state emerging in monolayer 1T-ZrTe2 and its investigation by angle-resolved photoemission spectroscopy (ARPES) and scanning tunneling microscopy (STM). The results show novel band- and energy-dependent folding behavior in a two-step process, which is the signatures of an exciton gas phase prior to its condensation into the final CDW state. Our findings provide a versatile two-dimensional platform that allows tuning of the excitonic effect.

Biomechanical Effect of Osteoporosis on Adjacent Segments After Anterior Cervical Corpectomy and Fusion.

BACKGROUND: Adjacent segmental degeneration (ASD) is one common long-term complication of anterior cervical corpectomy and fusion (ACCF), and osteoporosis is one basic disease in the elderly. After ACCF, patients may experience osteoporosis with age. However, the influence of osteoporosis on ASD remains unclear. The purpose of this study was to determine whether osteoporosis could affect the development of ASD following ACCF. METHODS: Three finite element models of the cervical spine, including 1 normal model, 1 ACCF model, and 1 ACCF with osteoporosis model, were constructed. ACCF was simulated at the C4-C6 level. A 73.6 N follower load and a 1 Nm moment were imposed on the normal model, and the same follower load together with an adjusted moment was applied to the ACCF model and the ACCF with osteoporosis model, to simulate movement in each direction. The range of motion, intradiscal pressure, shear stress on anulus fibrosus, and facet joint stress at C3-C4 and C6-C7 levels of the models were calculated. RESULTS: In this study, the normal model was well validated. In flexion, extension, right lateral bending, and right axial rotation, the overall range of motion was 8.92°, 19.7°, 15.37°, and 45.27° in the normal model, and the adjusted moment was 1.4 Nm, 2.7 Nm, 1.1 Nm, and 2.6 Nm in the ACCF model, and 1.3 Nm, 2.5 Nm, 1.1 Nm, and 2.4 Nm in the ACCF with osteoporosis model. Despite of a few exceptions, the maximum values of the outcome measurements were mostly found in the ACCF model, and the minimum values in the normal model. Compared with the ACCF model, most of the outcome measurements were decreased in the ACCF with osteoporosis model. CONCLUSIONS: Osteoporosis can retard the adverse influence of ACCF on adjacent segments.

Spinal cord injury target-immunotherapy with TNF-α autoregulated and feedback-controlled human umbilical cord mesenchymal stem cell derived exosomes remodelled by CRISPR/Cas9 plasmid.

Human umbilical cord mesenchymal stem cell (hucMSC) derived exosomes (EXOs) have been investigated as a new treatment for spinal cord injury (SCI) because of their anti-inflammatory, anti-apoptotic, angiogenesis-promoting, and axonal regeneration properties. The CAQK peptide found in the brains of mice and humans after trauma has recently been found to specifically bind to the injured site after SCI. Thus, we developed a nanocarrier system called EXO-C@P based on hucMSC exosomes remodelled by the CRISPR/Cas9 plasmid to control inflammation and modified by the CAQK peptide. EXO-C@P was shown to effectively accumulate at the injury site and saturate the macrophages to significantly reduce the expression of inflammatory cytokines in a mouse model of SCI. Moreover, EXO-C@P treatment improved the performance of mice in behavioural assessments and upregulated soluble tumour necrosis factor receptor-1 (sTNFR1) in serum and at the trauma site after SCI surgery, but lowered the proportion of iNOS+ cells and the concentration of proinflammatory factors. In conclusion, EXO-C@P provides an effective alternative to multiple topical administration and drug delivery approaches for the treatment of SCI. STATEMENT OF SIGNIFICANCE: SCI is a serious disease characterised by a high incidence, high disability rate, and high medical costs, and has become a global medical problem. Several studies have shown that the inflammatory response is the critical inducer of secondary injury after SCI. The inflammatory cytokine TNF-α is considered to be one of the most significant therapeutic targets for autoimmune diseases. Antibodies targeting TNF-α and sTNFR1 are capable of neutralising free TNF-α. In this study, exosomes in the CRISPR/Cas9 system were used to establish stem cells with an autoregulated and feedback-controlled TNF-α response, with these cells secreting sTNFR1, which neutralised TNF-α and antagonised the inflammation stimulated by TNF-α. Moreover, the plasmid was combined with CAQK, which targeted the injury site and promoted the recovery of SCI function.

Effect of Pedicle Screw Fixation on Adjacent Segments in Osteoporotic Spine Following Transforaminal Lumbar Interbody Fusion Under Whole Body Vibration.

BACKGROUND: Adjacent segmental degeneration (ASD) is the long-term complication of transforaminal lumbar interbody fusion (TLIF) combined with pedicle screw fixation. Both osteoporosis and whole-body vibration (WBV) can alter the biomechanics of adjacent segments. However, the effect of pedicle screw fixation on ASD in an osteoporotic spine after TLIF under WBV was unknown. METHODS: According to a previously validated model of L1-S1, 2 osteoporotic TLIF models with and without pedicle screw fixation were developed. In each model, a 400 N preload was applied and a 5-Hz, 40 N sinusoidal vertical load with a 40-kg mass point was imposed on the superior surface of L1. The parameters of intradiskal pressure, shear stress of annulus fibrosus, disk bulge, superior and inferior end plate stress, and facet joint contact pressure at L3-L4 and L5-S1 levels were evaluated. RESULTS: At L3-L4, the dynamic responses in intradiskal pressure, shear stress, facet joint contact pressure, superior end plate stress, and inferior end plate stress generated an increase after pedicle screw fixation, and their maximum values increased by 15.1%, 9.5%, 18.6%, 10.6%, and 9.3%, respectively. However, the parameter of disk bulge demonstrated an opposite trend. At L5-S1, the differences in maximum values of the parameters were slight and the corresponding dynamic response curves were close, overlapping, or intersecting. CONCLUSIONS: In an osteoporotic spine after TLIF, removal of pedicle screw fixation can mitigate ASD in the upper adjacent segment but has no apparent influence on the lower adjacent segment under WBV.

Effect of Osteoporosis on Adjacent Segmental Degeneration After Posterior Lumbar Interbody Fusion Under Whole Body Vibration.

BACKGROUND: Adjacent segmental degeneration (ASD) is one of the common complications after posterior lumbar interbody fusion (PLIF). Both whole body vibration (WBV) and osteoporosis are important factors associated with the biomechanics of the lumbar spine. However, to the best of our knowledge, no studies have investigated the effects of osteoporosis on ASD after PLIF under WBV. METHODS: In the present study, using one normal model, one PLIF model and one PLIF with osteoporosis model of the L1-S1 segment were developed. A 5-Hz, 40-N sinusoidal vertical load was imposed on the superior surface of L1 of each model to simulate WBV, and the dynamic responses and maximal values of intradiscal pressure, shear stress on annulus fibrosus, total deformation, and disc bulge were evaluated in the L1-L2, L2-L3, L3-L4, and L5-S1 segments. RESULTS: At the L1-L2, L2-L3, and L3-L4 levels, the differences in the dynamic responses and maximal values in intradiscal pressure, shear stress, total deformation, and disc bulge between the PLIF and PLIF with osteoporosis models were slight. However, at the L5-S1 level, the dynamic response curves and maximal intradiscal pressure, shear stress, and disc bulge values in the PLIF with osteoporosis model were significantly lower than those in the PLIF model. CONCLUSIONS: Osteoporosis can mitigate the development of ASD in the lower adjacent segment but has no obvious influence on the upper adjacent segments during WBV.

Imaging Dual-Moiré Lattices in Twisted Bilayer Graphene Aligned on Hexagonal Boron Nitride Using Microwave Impedance Microscopy.

Moiré superlattices (MSLs) formed in van der Waals materials have become a promising platform to realize novel two-dimensional electronic states. Angle-aligned trilayer structures can form two sets of MSLs which could potentially interfere. In this work, we directly image the moiré patterns in both monolayer and twisted bilayer graphene aligned on hexagonal boron nitride (hBN), using combined scanning microwave impedance microscopy and conductive atomic force microscopy. Correlation of the two techniques reveals the contrast mechanism for the achieved ultrahigh spatial resolution (<2 nm). We observe two sets of MSLs with different periodicities in the trilayer stack. The smaller MSL breaks the 6-fold rotational symmetry and exhibits abrupt discontinuities at the boundaries of the larger MSL. Using a rigid atomic-stacking model, we demonstrate that the hBN layer considerably modifies the MSL of twisted bilayer graphene. We further analyze its effect on the reciprocal space spectrum of the dual-moiré system.

Biomechanical effects of osteoporosis on adjacent segments after posterior lumbar interbody fusion: A finite element study.

OBJECTIVE: To investigate the biomechanical effects of osteoporosis on adjacent segments after posterior lumbar interbody fusion (PLIF). METHODS: This study was designed and conducted in the Traumatology and Orthopedics Laboratory, School of Chinese Medicine, Jinan University, Guangzhou, China, between December 2019 and February 2020. A healthy finite element model of L3-S1 was developed along with one PLIF model and one PLIF with osteoporosis model. Based on a hybrid test method, the inferior surface of S1 was entirely fixed, and a preload of 400N combined with an adjusted moment was imposed on the superior surface of L3 in each model to simulate flexion, extension, lateral bending and axial rotation. The intradiscal pressure (IDP), shear stress on annulus fibrosus, and the range of motion (ROM) of L3-L4 and L5-S1 were calculated and compared. RESULTS: In each direction, the highest value of IDP and shear stress on annulus fibrosus at L3-L4 and L5-S1 was found in the PLIF model, and the lowest value in the healthy model. The largest ROM at L4-L5 appeared in the healthy model, and the smallest value in the PLIF model in each direction. At L3-L4 and L5-S1, the highest ROM in most directions was found in the PLIF model, followed by the PLIF with osteoporosis model, and the lowest value in the healthy model. CONCLUSIONS: Osteoporosis can decrease IDP, shear stress on annulus fibrosus, and ROM at adjacent levels, and slow down the development of ASD after PLIF.

Enhanced heterogeneous Fenton-like degradation of refractory organic contaminants over Cu doped (Mg,Ni)(Fe,Al)2O4 synthesized from laterite nickel ore.

The heterogeneous Fenton-like catalyst (Mg,Cu,Ni)(Fe,Al)2O4 was synthesized via a coprecipitation method using laterite nickel ore leaching solution as raw material. The effects of CuCl2·2H2O addition and calcination temperature on the microstructures and degradation properties of the obtained products were investigated. Results showed that higher calcination temperature could promote the migration of Cu2+ ions from CuO to the spinel ferrite lattice and occupied octahedral sites. The degradation efficiencies (η) of various types of low-concentration dyes and tetracycline were higher than 95%, which was mainly due to the accelerated generation of OH radicals by the synergistic effect of Fe3+ and Cu2+ ions in octahedral sites of the formed (Mg,Cu,Ni)(Fe,Al)2O4. Moreover, after five consecutive degradation cycles, the η of RhB was still close to 100%, TOC removal efficiency was maintained around 40% and the concentrations of metallic ions in degraded solutions were all lower than the national effluent discharge standard (GB8978-1996), confirming the as-obtained (Mg,Cu,Ni)(Fe,Al)2O4 was an eco-friendly heterogeneous Fenton-like catalyst with excellent stability and reusability. This study may provide an effective reference for large scale preparing efficient heterogeneous Fenton-like catalysts from natural minerals in treating the wastewater contaminated by refractory organics.

Tui Na for Chronic Nonspecific Low Back Pain: Protocol for a Systematic Review and Meta-analysis.

BACKGROUND: Chronic nonspecific low back pain (CNLBP) is one of the most common complex pain conditions, and it is strongly associated with high rates of disability. Even though several studies on Tui na for CNLBP have been reported, to our knowledge there has been no systematic review of the currently available publications. OBJECTIVE: This study aims to develop a protocol for a systematic review and meta-analysis that will evaluate the effectiveness and safety of Tui na therapy for patients with CNLBP. METHODS: An electronic literature search of PubMed, Embase, MEDLINE, Cochrane Library, Springer, Scopus, World Health Organization International Clinical Trials Registry Platform, Physiotherapy Evidence Database (PEDro), Clarivate Analytics, and Chinese biomedical databases (the China National Knowledge Infrastructure, Wan-fang database, Chinese Scientific Journals Database, and Chinese Biomedical Literature Databases) will be conducted. Studies will be screened by two reviewers independently based on titles and abstracts, followed by a full-text reading with eligibility criteria. Randomized controlled trials involving Tui na for patients with CNLBP will be reviewed. The primary outcomes of the study are improvement of pain, analgesic medication reduction, improvement of functional disability, and degree of satisfaction with the intervention. A secondary outcome is any adverse event of Tui na intervention. Methodological quality and risk of bias will be assessed with the Cochrane Collaboration Risk of Bias Tool. If studies are sufficient, a meta-analysis of the effectiveness will be performed. If possible, we will evaluate publication bias using funnel plots. If substantial heterogeneity between studies is present, and there are sufficient studies, subgroup analyses will be conducted to explain the study findings. RESULTS: The review database searches will be initiated in December 2020, with findings expected by January 2021. CONCLUSIONS: This protocol will establish a framework of a high-quality literature synthesis on the impact of Tui na treatment in patients with CNLBP. The proposed review will determine whether Tui na is effective and safe for CNLBP patients. TRIAL REGISTRATION: PROSPERO CRD42020166731; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=166731. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/20615.

Comparison Between 7 Osteoporotic Vertebral Compression Fractures Treatments: Systematic Review and Network Meta-analysis.

BACKGROUND: Vertebroplasty (VP), kyphoplasty (KP), SpineJack system (SJ), radiofrequency kyphoplasty (RFK), Kiva system (Kiva), Sky kyphoplasty system (SK), and conservative treatment are widely used in the treatment of osteoporotic vertebral compression fractures (OVCFs). However, it is still unknown which is the best intervention. The aim of the current study was to evaluate the effectiveness and safety of VP, KP, SJ, RFK, Kiva, SK, and CT in the treatment of OVCFs. METHODS: Randomized controlled trials and cohort studies comparing VP, KP, SJ, RFK, Kiva, SK, or CT for the treatment of OVCFs were identified on the basis of databases including PubMed, the Cochrane Library, Web of Science, and Springer Link. A network meta-analysis was performed using STATA 15.1. RESULTS: A total of 56 studies with 6974 patients and 7 interventions were included in this study. The results of the surface under the cumulative probability demonstrated that SK was the best intervention in decreasing VAS scores and recovering middle vertebral height, RFK was the best intervention in improving ODI scores and decreasing incidence of new fractures, SJ was the best intervention to restore kyphosis angle, and Kiva was the best intervention to reduce incidence of bone cement leakage. Cluster analysis showed that SK was the preferable intervention on the basis of the outcomes of VAS, ODI, middle vertebral height, and kyphotic angle, and RFK was the preferable treatment in decreasing the incidence of adverse events. In our network meta-analysis, node-splitting analysis and loop inconsistency analysis showed no significant inconsistencies. CONCLUSIONS: SK may be the most effective treatment in relieving pain, improving the quality of life, and recovering vertebral body height and kyphotic angle, while RFK may be the safest intervention for OVCFs. However, considering the limitations of this study, more high-quality trials are needed in the future to confirm the current conclusion.

Does Osteoporosis Affect the Adjacent Segments Following Anterior Lumbar Interbody Fusion? A Finite Element Study.

BACKGROUND: Adjacent segment degeneration is a common complication following anterior lumbar interbody fusion (ALIF). Osteoporosis is becoming increasingly prevalent in the elderly population and thus patients undergoing ALIF may experience osteoporosis with age. However, the influence of osteoporosis on adjacent segment degeneration after ALIF remains unclear. METHODS: Three finite element models of the L3-S1 segment, including a healthy model, an ALIF model, and an ALIF with osteoporosis model, were used for analysis. ALIF was simulated at the L4-L5 segment. Based on a hybrid test method, the models were imposed with a preload of 400 N and an adjusted moment in flexion, extension, lateral bending, and axial torsion. Intradiscal pressure, shear stress on anulus fibrosus, and range of motion at L3-L4 and L5-S1 were calculated and compared. RESULTS: In each direction, the maximal values of intradiscal pressure and shear stress on anulus fibrosus at L3-L4 and L5-S1 were found in the ALIF model, and the minimal values were found in the healthy model. At L3-L4 and L5-S1, the maximal values of range of motion in most directions were found in the ALIF model followed by the ALIF with osteoporosis model, and the minimal values were found in the healthy model. However, the maximal value of range of motion at L5-S1 in axial torsion was found in the ALIF with osteoporosis model. CONCLUSIONS: Osteoporosis may mitigate the adverse influence of ALIF on adjacent segments.

Comparative Efficacy of Graft Options in Anterior Cruciate Ligament Reconstruction: A Systematic Review and Network Meta-Analysis.

PURPOSE: To evaluate the effectiveness of various graft options for anterior cruciate ligament reconstruction using network meta-analysis. METHODS: A medical literature search was conducted of PubMed, the Cochrane Library, Embase, SCOPUS, and Web of Science from their inception through March 1, 2019. The outcomes, including International Knee Documentation Committee (IKDC) form, Lachman test, Lysholm score, Pivot shift test, and Tegner score, were evaluated among graft options. Data extraction was carried out according to inclusion and exclusion criteria, and a network meta-analysis was performed using STATA 14.0. RESULTS: A total of 45 trials with 3992 patients were included. The forest plots revealed no significant differences in IKDC, Lysholm, or Tegner score among the grafts. In Lachman score, a significant difference was found in the comparisons of hamstring tendon allograft (HT-AL) versus patellar tendon autograft (PT-AU) and HT-AL versus hamstring tendon autograft (HT-AU). In pivot shift test, PT-AU was superior to all the other grafts, and quadriceps tendon autograft (QT-AU) was superior to HT-AL and artificial ligament (Art-L) in the number of cases with negative results. According to surface under the cumulative ranking area (SUCRA), PT-AU had the highest probability to be the best intervention in Lachman test and Tegner score; tibialis anterior tendon allograft (TA-AL) in IKDC and Lysholm score; and QT-AU in pivot shift test. Based on the cluster analysis of SUCRA, PT-AU was considered the most appropriate intervention by IKDC and Lachman test. CONCLUSION: This study suggests that PT-AU may be the most appropriate graft for ACL reconstruction according to IKDC and Lachman test results. LEVEL OF EVIDENCE: Level I, network meta-analysis of randomized controlled trials.

Biomechanical Comparison of Lumbar Fixed-Point Oblique Pulling Manipulation and Traditional Oblique Pulling Manipulation in Treating Lumbar Intervertebral Disk Protrusion.

OBJECTIVE: To compare the biomechanical effect of lumbar fixed-point oblique pulling manipulation and traditional oblique pulling manipulation in the treatment of protrusion of lumbar intervertebral disk, and investigate the influence of disk degeneration on the 2 manipulations. METHODS: Three finite element models including 1 normal model, 1 mild degeneration, and 1 moderate degeneration model of L3-S1 were developed to simulate 2 oblique pulling manipulations. The disk protrusion was assumed to be in the left central and subarticular zone of the L4-L5 disk, and manipulations were carried out on the right. A 15-Nm right axial rotation moment and 150-N compressive loading were imposed on the upper endplate of L3 to simulate a traditional oblique pulling manipulation. To simulate lumbar fixed-point oblique pulling manipulation, in addition to a 15-Nm moment and 150-N compressive loading imposed on the L3 upper endplate, a 50-N force was imposed on the right lateral area of the L4 spinous process in a left front direction. The displacement and stress in the left central and subarticular zone of the L4-L5 disk were calculated and compared in the 3 models. RESULTS: The average displacement and stress in the left central and subarticular zone of L4-L5 disk were higher in fixed-point oblique pulling manipulation than those in traditional oblique pulling manipulation (P < .05). In addition, the values of average stress and displacement decreased significantly with the increase of lumbar disk degeneration (P < .05). CONCLUSION: Lumbar fixed-point oblique pulling manipulation showed a better biomechanical effect than traditional oblique pulling manipulation, and lumbar disk degeneration affected the 2 manipulations adversely in the virtual treatment of protrusion of the lumbar intervertebral disk using finite element models.

Metallic surface states in a correlated d-electron topological Kondo insulator candidate FeSb2.

The resistance of a conventional insulator diverges as temperature approaches zero. The peculiar low-temperature resistivity saturation in the 4f Kondo insulator (KI) SmB6 has spurred proposals of a correlation-driven topological Kondo insulator (TKI) with exotic ground states. However, the scarcity of model TKI material families leaves difficulties in disentangling key ingredients from irrelevant details. Here we use angle-resolved photoemission spectroscopy (ARPES) to study FeSb2, a correlated d-electron KI candidate that also exhibits a low-temperature resistivity saturation. On the (010) surface, we find a rich assemblage of metallic states with two-dimensional dispersion. Measurements of the bulk band structure reveal band renormalization, a large temperature-dependent band shift, and flat spectral features along certain high-symmetry directions, providing spectroscopic evidence for strong correlations. Our observations suggest that exotic insulating states resembling those in SmB6 and YbB12 may also exist in systems with d instead of f electrons.