Polymer Engineering Enables High Linear Capacity Fiber Electrodes by Microenvironment Regulation.

Unlike bulky and rigid traditional power systems, 1D fiber batteries possess appealing features such as flexibility and adaptability, which are promising for use in wearable electronic devices. However, the performance and energy density fiber batteries are limited by the contradiction between ionic transfer and robust structure of fiber electrodes. Herein, these problems are addressed via polymer engineering to regulate the microenvironment in electrodes, realizing high-linear-capacity thick fiber electrodes with excellent cycling performance. The porosity of the electrodes is regulated using polymer crosslink networks designed with various components, and lithium-ion transfer is optimized through ether-abundant polymer chains. Furthermore, reinforced covalent bonding with carbon nanotube networks is established based on the modified functional groups of polymer networks. The multiscale optimizations of the porous structure, ionic transportation, and covalent bonding network enhance the lithium-ion dynamics property and structural stability. Therefore, ultrahigh linear-capacity fiber electrodes (17.8 mAh m-1) can be fabricated on a large scale and exhibit excellent stability (92.8% after 800 cycles), demonstrating obvious superiority among the reported fiber electrodes. Moreover, this study highlights the high effectiveness of polymer regulation in fiber electrodes and offers new avenues for designing next-generation wearable energy-storage systems.

Beyond Growth Hormone: Association of Short Stature Types and Growth Hormones With Scoliosis.

STUDY DESIGN: Cross-sectional and retrospective cohort study. OBJECTIVE: We investigated the effect of 3 types of short stature [partial growth hormone deficiency (GHD), GHD, and idiopathic short stature (ISS)] and recombinant human growth hormone (rhGH) therapy on scoliosis. SUMMARY OF BACKGROUND DATA: In short stature, rhGH is widely used and the concentration of growth hormone varies among types. The epidemiologic characteristics of scoliosis and the role of rhGH in scoliosis remain unclear. PATIENTS AND METHODS: A cross-sectional study was conducted among 3896 patients with short stature (partial GHD, GHD, and ISS), and a 1:1 age and sex-matched control group with preexisting whole-spine radiographs. The cohort study included 2605 subjects who underwent radiography more than twice to assess scoliosis development, progression, and the need for bracing and surgery. Adjusted logistic regression was used to assess differences in the prevalence of scoliosis among patients with partial GHD, GHD, ISS, and controls. The Kaplan-Meier method was used to analyze the time course of scoliosis development and progression. Cox regression was applied to assess the independent factors related to scoliosis development and progression. Mendelian randomization analyses were also performed. RESULTS: Compared with controls, patients with short stature had a higher incidence of scoliosis (34.47% in partial GHD, 31.85% in GHD, 32.94% in ISS vs . 8.83% in control, P < 0.001), a higher risk of scoliosis development [hazard ratio (HR) = 1.964 in partial GHD, P < 0.001; HR = 1.881 in GHD, P = 0.001; HR = 1.706 in ISS, P = 0.001), but not a higher risk of progression, brace, or surgery. Among the 3 types of short stature, there were no differences in the incidence, development, and progression of scoliosis or the need for bracing or surgery. RhGH treatment increased the risk of scoliosis development in each short-stature group (HR = 2.673 in partial GHD, P < 0.001; HR = 1.924 in GHD, P = 0.049; HR = 1.564 in ISS, P = 0.004). Vitamin D supplementation was protective against scoliosis development (HR = 0.456 in partial GHD, P = 0.003; HR = 0.42 in GHD, P = 0.013; HR = 0.838 in ISS, P = 0.257). CONCLUSIONS: More attention should be paid to the spinal curve in patients with partial GHD, GHD, or ISS. For short stature treated with rhGH, the risk of scoliosis development was increased. Vitamin D supplementation may be beneficial for prevention. LEVEL OF EVIDENCE: Level III.

Ionic Layer Epitaxy Growth of Organic/Inorganic Composite Protective Layers for Large-Area Li and Zn Metal Anodes.

Li and Zn metal batteries using organic and aqueous electrolytes, respectively, are desirable next-generation energy storage systems to replace the traditional Li-ion batteries. However, their cycle life and safety performance are severely constrained by a series of issues that are attributed to dendrite growth. To solve these issues, a nanothick ZnO-oleic acid (ZnO-OA) composite protective layer is developed by a facile ionic layer epitaxy method. The ZnO-OA layer provides strong lithophilic and zincophilic properties, which can effectively induce uniform ion deposition. As a result, the ZnO-OA protected Li and Zn metal anodes can cycle stably for over 600 and 1000 h under a large current density of 10 mA cm-2. Employing the ZnO-OA protected anodes, the Li||LiFePO4 cell can maintain a capacity retention of 99.5% after 600 cycles at a 1 C rate and the Zn||MnO2 cell can operate stably for 1000 cycles at 1 A g-1 current density.

Oxygen Radical Anion Substituted Iron Phthalocyanine as an Effective Redox Mediator for Li-O2 Batteries.

Transition metal phthalocyanines are potential soluble redox mediators for Li-O2 batteries. In this work, effective strategies to control the redox potentials and activities of iron phthalocyanine (FePc) based redox mediators are designed by the introduction of electron-withdrawing or electron-donating groups. Substituted electron-donating groups can shift the oxidation potential of FePc to a higher energy level, consequently reducing the charging voltage of Li-O2 batteries. Especially, oxygen radical anion (-O-) modified FePc (FePc-O-) shows the most significant improvement to the oxygen reduction and evolution reactions of Li-O2 batteries. Electronic analysis indicates that -O- substitution can break the symmetry of electronic structures of FePc which further tunes the reduction of O2 and the oxidation of Li2O2. Detailed reaction mechanisms of (FePc-O-)-mediated Li-O2 batteries are proposed based on first-principles molecular dynamics simulations and thermodynamic free energy calculations.

A Multifunctional Organic Electrolyte Additive for Aqueous Zinc Ion Batteries Based on Polyaniline Cathode.

The practical applications of aqueous zinc ion batteries are hindered by the formation of dendrites on the anode, the narrow electrochemical window of electrolyte, and the instability of the cathode. To address all these challenges simultaneously, a multi-functional electrolyte additive of 1-phenylethylamine hydrochloride (PEA) is developed for aqueous zinc ion batteries based on polyaniline (PANI) cathode. Experiments and theoretical calculations confirm that the PEA additive can regulate the solvation sheath of Zn2+ and form a protective layer on the surface of the Zn metal anode. This broadens the electrochemical stability window of the aqueous electrolyte and enables uniform deposition of Zn. On the cathode side, the Cl- anions from PEA enter the PANI chain during charge and release fewer water molecules surrounding the oxidized PANI, thus suppressing harmful side reactions. When used in a Zn||PANI battery, this cathode/anode compatible electrolyte exhibits excellent rate performance and long cycle life, making it highly attractive for practical applications.

Uniform Zinc Deposition Regulated by a Nitrogen-Doped MXene Artificial Solid Electrolyte Interlayer.

The dendrite growth and side reactions of zinc metal anode in mildly acidic electrolytes seriously hinder the practical application of aqueous zinc-ion battery. To address these issues, an artificial protective layer of nitrogen-doped MXene (NMX) is used to protect the zinc anode. The NMX protective layer has high conductivity and uniformly distributed zincophilic sites, which can not only homogenize the local electric field on the electrode interface but also accelerate the kinetics for Zn deposition. As a result, the NMX protective layer induces uniform zinc deposition and reduces the overpotential of the electrode. Encouragingly, this NMX-protected Zn anode can cycle stably for 1900 h at 1 mA cm-2 and 1 mAh cm-2 . In asymmetric cells, it achieves high cycle reversibility with an average Coulomb efficiency of 99.79% for 4800 cycles at 5 mA cm-2 .

Ultrastretchable and adhesive agarose/Ti3C2Tx-crosslinked-polyacrylamide double-network hydrogel for strain sensor.

A novel agarose/Ti3C2Tx-crosslinked-polyacrylamide (AG/T-PAM) double-network (DN) hydrogel is synthesized by combining heating-cooling and γ-ray radiation-induced polymerization. The AG/T-PAM DN hydrogel possesses excellent mechanical properties with 4250% stretchability, and good adhesion to different substrates, such as an adhesive strength of 1148 kPa to copper at 30 °C. The resultant hydrogel also exhibits excellent tensile and compression sensing properties due to the variation of conductive network within hydrogel. The flexible and wearable strain sensor composed of the AG/T-PAM DN hydrogel presents rapid response to strain withstand 1000 cycles, and can monitor various movements of human body with a high sensibility. The AG/T-PAM DN hydrogel-based strain sensor will have broad application in large-scale strain detection scenarios requiring high sensitivity and adhesion.

Polyacrylamide/Copper-Alginate Double Network Hydrogel Electrolyte with Excellent Mechanical Properties and Strain-Sensitivity.

The double network (DN) hydrogel has attracted great attention due to its wide applications in daily life. However, synthesis DN hydrogel with excellent mechanical properties is still a big challenge. Here, polyacrylamide/copper-alginate double network (PAM/Cu-alg DN) hydrogel electrolyte is successfully synthesized by radiation-induced polymerization and cross-linking process of acrylamide with N, N'-methylene-bis-acrylamide and subsequent cupric ion (Cu2+ ) crosslinking of alginate. The content of sodium alginate, absorbed dose, and the concentration of Cu2+ are investigated in detail for improving the overall properties of PAM/Cu-alg DN hydrogel electrolyte. The PAM/Cu-alg DN hydrogel electrolyte synthesizes by radiation technique and Cu2+ crosslinking shows superior mechanical properties with a tensile strength of 2.25 ± 0.02 MPa, excellent energy dissipation mechanism, and the high ionic conductivity of 4.08 ± 0.17 mS cm-1 . PAM/Cu-alg DN hydrogel is characterized with attenuated total reflection Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, and X-ray photoelectron spectroscopy analyses and the reason for the improvement of mechanical properties is illustrated. Furthermore, PAM/Cu-alg DN hydrogel electrolyte exhibits excellent strain-sensitivity, cyclic stability, and durability. This work paves for the new way for the preparation of DN hydrogel electrolytes with excellent properties.

Grape seed procyanidins suppress the apoptosis and senescence of chondrocytes and ameliorates osteoarthritis via the DPP4-Sirt1 pathway.

Osteoarthritis (OA) is a complicated pathological condition affecting thousands of people around world, many with substantial unmet medical care needs and without any effective therapies. Previous study has indicated that glucagon-like peptide-1 (GLP-1) is involved in the pathological progress of osteoarthritis; however, the role of dipeptidase-4 (DPP4), which regulates the degradation of GLP-1, still remains unclear in osteoarthritis. Herein, after comparing normal mouse cartilage tissues with OA mouse cartilage tissues by histological analysis, we found out that DPP4 was highly expressed in OA cartilage tissues. To investigate the role of DPP4 in osteoarthritis, the apoptosis and senescence of chondrocytes were found to be decreased in vitro when DPP4 was downregulated by siRNA in chondrocytes. Further study showed that the inhibition of DPP4 by procyanidins, a grape seed extract, attenuated apoptosis and senescence of chondrocytes in vitro. Furthermore, the results showed that DPP4 inhibition protects cartilage by activating Sirt1, which has been reported to be associated with many pathophysiological processes, particularly in age-related diseases, such as neurodegenerative disorders and osteoarthritis. In addition, animal experiment results demonstrated that procyanidins were capable of ameliorating the progression of osteoarthritis through the inhibition of DPP4. This study provides a competitive target for the therapeutic treatment of osteoarthritis, and procyanidins were shown to be a potential medicine for the restoration of the effects of osteoarthritis.

One-Pot Hydrothermal Preparation of Fe3O4 Decorated Graphene for Microwave Absorption.

Fe3O4 decorated graphene was synthesized for electromagnetic wave absorption via a facile one-pot hydrothermal approach. The structure and morphology of the as-prepared nanomaterials were systematically investigated. The graphene oxide (GO) was reduced and Fe3O4 nanoparticles were evenly decorated on the surface of reduced graphene oxide (rGO) nanosheets. The average particle size of Fe3O4 nanoparticles is about 15.3 nm. The as-prepared rGO-Fe3O4 nanocomposites exhibited a good microwave absorption performance because of the combination of graphene and magnetic Fe3O4. When the thicknesses are 1.6 mm and 6.5 mm, the reflection loss (RL) values are up to -34.4 dB and -37.5 dB, respectively. The effective bandwidths are 3.8 and 1.9 GHz.

Amphoteric Ion Exchange Membranes Prepared by Preirradiation-Induced Emulsion Graft Copolymerization for Vanadium Redox Flow Battery.

A series of poly(vinylidene difluoride)-based amphoteric ion exchange membranes (AIEMs) were prepared by preirradiation-induced graft copolymerization of styrene and dimethylaminoethyl methacrylate in an aqueous emulsion media followed by solution casting, sulfonation, and protonation. The effects of absorbed dose and comonomer concentration on grafting yield (GY) were investigated. The highest GY of 44.5% at a low comonomer concentration of 0.9 M could be achieved. FTIR, TGA, and X-ray photoelectron spectroscopy (XPS) confirmed the successful grafting and sulfonation of the as-prepared AIEMs. Properties of the AIEMs such as water uptake, ion exchange capacity (IEC), ionic conductivity, and crossover behavior of VO2+ ions prepared by this novel technique were systematically investigated and compared with those of the commercial Nafion 115 membrane. It was found that at a GY of 28.4%, the AIEMs showed higher IEC and conductivity, lower permeability of VO2+ ions, and a longer time to maintain open circuit voltage than Nafion 115, which was attributed to their high GY and elaborate amphoteric structure. Consequently, this work has paved the way for the development of green and low-cost AIEMs with good performance for vanadium redox flow battery applications.

Melatonin ameliorates intervertebral disc degeneration via the potential mechanisms of mitophagy induction and apoptosis inhibition.

Intervertebral disc degeneration (IDD) is a complicated disease in patients. The pathogenesis of IDD encompasses cellular oxidative stress, mitochondrion dysfunction and apoptosis. Melatonin eliminates oxygen free radicals, regulates mitochondrial homoeostasis and function, stimulates mitophagy and protects against cellular apoptosis. Therefore, we hypothesize that melatonin has beneficial effect on IDD by mitophagy stimulation and inhibition of apoptosis. The effects of melatonin on IDD were investigated in vitro and in vivo. For the former, melatonin diminished cellular apoptosis caused by tert-butyl hydroperoxide in nucleus pulposus (NP) cells. Mitophagy, as well as its upstream regulator Parkin, was activated by melatonin in both a dose and time-dependent manner. Mitophagy inhibition by cyclosporine A (CsA) partially eliminated the protective effects of melatonin against NP cell apoptosis, suggesting that mitophagy is involved in the protective effect of melatonin on IDD. In addition, melatonin was demonstrated to preserve the extracellular matrix (ECM) content of Collagen II, Aggrecan and Sox-9, while inhibiting the expression of matrix degeneration enzymes, including MMP-13 and ADAMTS-5. In vivo, our results demonstrated that melatonin treatment ameliorated IDD in a puncture-induced rat model. To conclude, our results suggested that melatonin protected NP cells against apoptosis via mitophagy induction and ameliorated disc degeneration, providing the potential therapy for IDD.

Factors Associated with Cervical Spine Alignment in an Asymptomatic Population: A Preliminary Analysis.

BACKGROUND: Cervical sagittal imbalance compromises health-related quality of life and can lead to myriad incapacitating symptoms through compression of the spinal cord. Questions regarding which parameters play primary roles in the progression of cervical sagittal imbalance and which might be compensatory factors remain unanswered. METHODS: This study enrolled 246 asymptomatic volunteers from July 2016 to June 2018. After demographic and radiologic parameters were measured, the data were analyzed using correlation coefficient test and multiple regression analysis. A predictive equation was assessed with variance analysis, residual analysis, collinearity analysis, and a paired t test. RESULTS: Average values are as follows: orbital tilt, 64 ± 6°; orbital slope (OS), 15 ± 6°; C0-C2 lordosis (C0C2), 28 ± 8°; cervical lordosis (CL), 5 ± 11°; C2-C7 sagittal vertical axis (C2C7SVA), 15 ± 8 mm; T1 slope (TS), 17 ± 6°; thoracic inlet angle, 69 ± 8°; thoracic kyphosis, 34 ± 9°; lumbar lordosis, 50 ± 10°; sacral slope, 38 ± 7°; pelvic index, 48 ± 9°; sagittal vertical axis, 10 ± 19 mm. Correlations of C2C7SVA were observed with body mass index (BMI), OS, C0C2, CL, and TS. The validated predictive equation was: C2C7SVA = 0.38 × BMI - 0.73 × OS + 0.73 × C0C2 + 0.15 × CL + 0.18 × TS - 6.53. CONCLUSIONS: BMI, OS, C0C2, CL, and TS were primary influencers in the progression of cervical sagittal imbalance and established a predictive equation of asymptomatic population, which can provide clinical advice and remind surgeons of the primary influencers of reconstructive surgery for better prognoses.

Berberine suppresses apoptosis and extracellular matrix (ECM) degradation in nucleus pulposus cells and ameliorates disc degeneration in a rodent model.

Intervertebral disc degeneration (IVDD) is a chronic disease with complicated pathology involving nucleus pulposus (NP) cell apoptosis and extracellular matrix (ECM) degradation. Previous studies have shown that moderate autophagy has a protective effect against apoptosis in NP cells. Berberine (BBR) is an alkaloid compound with many beneficial properties including antimicrobial, anti-inflammatory, antioxidative, and anti-apoptotic activity. Recently, it was found to induce autophagy in various tissues as well. Thus, we hypothesized that BBR may exert a therapeutic effect on IVDD through autophagy activation. In this study, we investigated the effects of BBR on IVDD and delineated a potential mechanism. BBR treatment in vitro inhibited the expression of pro-apoptotic proteins induced by tert-butyl hydroperoxide (TBHP), and increased the expression of anti-apoptotic Bcl-2. Furthermore, it prevented ECM degradation by inhibiting the production of matrix-degrading enzymes. Additionally, BBR treatment significantly activated autophagy in NP cells. However, autophagy inhibition markedly suppressed BBR's effects on NP cell apoptosis and ECM degeneration, indicating that autophagy activation with BBR treatment is protective against IVDD. In vivo, BBR treatment increased the expression of LC3 in disc cells and prevented the development of IVDD in a needle puncture-induced rat model. Thus, BBR stimulates autophagy as a protective mechanism against NP cell apoptosis and ECM degeneration, revealing its therapeutic potential in the treatment of IVDD.

Rate of presence of 11 thoracic vertebrae and 6 lumbar vertebrae in asymptomatic Chinese adult volunteers.

BACKGROUND: An increasing number of studies on spinal morphology in asymptomatic Asian and Western patients have been reported. Variation in spinal anatomy among patients is considered as the cause of wrong-level surgery in up to 40% of cases. The present study examined the rate of presence of 11 thoracic vertebrae and 6 lumbar vertebrae in 293 asymptomatic Chinese adult volunteers. METHODS: From May 27, 2016, to November 11, 2017, a cohort of 325 asymptomatic Chinese adults meeting the study exclusion criteria was recruited. The radiographs were examined by a spine surgeon and a radiologist to assess the number of thoracic and lumbar vertebrae. RESULTS: In total, 293 volunteers were included in this study: 17 (5.8%) had 11 thoracic vertebrae, and 16 (5.5%) had 6 lumbar vertebrae. Among all volunteers, 12 (4.1%) had 7 cervical vertebrae (C), 11 thoracic vertebrae (T), and 5 lumbar vertebrae (L); 5 (1.7%) had 7C, 11T, and 6L; and 11 (3.8%) had 7C, 12T, and 6L. There was no difference between the findings of the spine surgeon and the radiologist. CONCLUSIONS: For the first time, this study describes the rate of presence of 11 thoracic vertebrae and 6 lumbar vertebrae in 293 asymptomatic Chinese adult volunteers. Variations in the number of thoracic and lumbar vertebrae tend to be ignored by spine surgeons. We encourage spinal surgeons and researchers to be aware of such variations when performing thoracic- and lumbar-level surgery and assessing spinal alignment and parameters.

A Novel Knotless Barbed Suture Technique for Traumatic Thoracolumbar Fracture in Posterior Surgery.

BACKGROUND: Surgical wound closure directly influences spinal surgical efficiency and several postoperative complications. The traditional suture technique is time-consuming and associated with greater rates of complications. Bidirectional absorbable barbed sutures seem to compensate for some of the limitations of traditional suture; however, they rarely are reported in spinal surgery. We designed a novel suture technique for use in thoracolumbar spinal surgery. METHODS: The data of 189 patients with traumatic thoracolumbar fractures were analyzed between bidirectional barbed suture closure and traditional interrupted suture closure. Data of operative time, wound closure time, length of incision, intraoperative blood loss, complications of wound dehiscence and postoperative hematoma, cost, and neurologic status were collected. RESULTS: No significant differences were observed in the baseline demographics of included patients. Compared with the traditional suturing group, the barbed sutures decreased the mean operative time (P = 0.037), suture time (P < 0.01), and mean suturing time (P < 0.01) significantly, although no statistically significant differences were found in blood loss (P = 0.724) and neurologic functional scores (preoperative: P = 0.901; 3 months after surgery: P = 0.208; final follow-up assessments: P = 0.163), and no statistically significant differences were found in rates of postoperative infection, hematoma, and wound dehiscence. CONCLUSIONS: Our findings suggest that the novel knotless barbed suture has comparable strength to traditional sutures, with the advantage of less suturing time. It is an efficient, safe technique, and alternative choice for patients with thoracolumbar fracture after posterior surgery.

Oxidized multiwall carbon nanotube/silicone foam composites with effective electromagnetic interference shielding and high gamma radiation stability.

Oxidized multiwall carbon nanotubes (o-MWCNTs) were introduced into silicone foam to fabricate an electromagnetic interference (EMI) shielding material with high gamma radiation stability by solution casting followed by foaming and cross-linking reactions. The as-prepared o-MWCNT/silicone foam composites exhibited excellent mechanical strength and effective EMI shielding properties with superior EMI shielding effectiveness (SE) ranging from 26 to 73 dB at a 0.5-6.4 mm thickness with 30 wt% o-MWCNTs in the Ku band. Moreover, the composites have good gamma radiation stability, showing relatively stable EMI shielding properties and an improvement of hardness and pressure resistance after gamma irradiation with the absorbed dose of 500 kGy. These results indicate that the o-MWCNT/silicone foam composite is an attractive candidate for EMI shielding in some ionizing radiation environments.

Polymeric ionic liquid gels composed of hydrophilic and hydrophobic units for high adsorption selectivity of perrhenate.

The removal of TcO4 - from aqueous solutions has attracted more and more attention recently, and ReO4 - has been widely used as its natural analog. In this work, polymeric ionic liquid gel adsorbents, PC2-C12vimBr, with high adsorption capacity and selectivity towards ReO4 - were synthesized by radiation-induced polymerization and crosslinking. PC2-C12vimBr was composed of two monomers: a hydrophobic unit, 1-vinyl-3-dodecylimidazolium bromide for high selectivity, and a hydrophilic unit, 1-vinyl-3-ethylimidazolium bromide for improved kinetics. A gel fraction up to 90% could be achieved under 40 kGy with varied monomer ratios. The adsorption of PC2-C12vimBr gels for ReO4 - was evaluated by batch adsorption. The PC2-C12vimBr gel containing 20 mol% hydrophilic unit (named PC2-C12vimBr-A) could significantly improve the adsorption kinetics, which had an equilibrium time of ca. 24 h. The adsorption capacity obtained from the Langmuir model was 559 mg g-1 (Re/gel). The selective factor against NO3 - was 33.4 ± 1.9, which was more than 10 times higher than that of PC2vimBr, and it could maintain ReO4 - uptake as high as 100 mg g-1 in 0.5 mol kg-1 HNO3. The ΔHΘ and ΔSΘ of the NO3 -/ReO4 - ion-exchange reaction of PC2-C12vimNO3-A were -16.9 kJ mol-1 and 29 J mol-1 K-1, respectively, indicating physical adsorption. The adsorption mechanism of ReO4 - onto PC2-C12vimBr-A gel was ion-exchange, and it could be recovered using 5.4 mol kg-1 HNO3.

Celastrol reduces IL-1ß induced matrix catabolism, oxidative stress and inflammation in human nucleus pulposus cells and attenuates rat intervertebral disc degeneration in vivo.

Celastrol has been reported to exert therapeutic potential on pro-inflammatory diseases including asthma, Crohn's disease, arthritis and neurodegenerative disorders via inhibiting NF-κB pathway. While the effect of celastrol on intervertebral disc degeneration (IDD), which is also a pro-inflammatory disease, remains unknown. In this study, we evaluated the effect of celastrol on IDD in IL-1ß treated human nucleus pulposus cells in vitro as well as in puncture induced rat IDD model in vivo. Our results showed that celastrol reduced the expression of catabolic genes (MMP-3, 9, 13, ADAMTS-4, 5), oxidative stress factors (COX-2, iNOS) and pro-inflammatory factors (IL-6, TNF-a) induced by IL-1ß in nucleus pulposus cells, also phosphorylation of IκBα and p65 were attenuated by celastrol, indicating NF-κB pathway was inhibited by celastrol in nucleus pulposus cells. In vivo study showed that celastrol treated rats had stronger T2-weighted signal than vehicle-treated rats at 2 weeks and 6 weeks' time point, suggesting celastrol could attenuate intervertebral disc degeneration in vivo. Together, our study demonstrates that celastrol could reduce IL-1ß induced matrix catabolism, oxidative stress and inflammation in human nucleus pulposus cells and attenuates rat intervertebral disc degeneration in vivo, which shows its potential to be a therapeutic drug for IDD.

Risk factors of kyphosis recurrence after implant removal in thoracolumbar burst fractures following posterior short-segment fixation.

PURPOSE: Our aim was to evaluate the results of short-segment pedicle instrumentation with screw insertion in the fracture level and find factors predicting kyphosis recurrence in thoracolumbar burst fractures. METHODS: We retrospectively analysed 122 patients with thoracolumbar burst fracture who were divided into two groups: kyphosis recurrence and no kyphosis recurrence. Pre-operative radiographic data comprising Cobb angle (CA), regional angle, anterior vertebra height (AVH), upper intervertebral angle, vertebral wedge angle (VWA), pre-anteroposterior A/P approach, superior endplate fracture, load-sharing classification (LSC) score and clinical data including age, visual analogue scale (VAS) score, thoracolumbar injury classification and severity score were compared between groups. T test, Pearson's chi-square and multivariate logistic regression were calculated for variables. RESULTS: CA, VWA and AVH were significantly corrected after surgery. CA changed from 23.7 to 3.0 (p <0.001), VWA from 38.7 to 9.6 (p <0.001) and AVH from 48.8 % to 91.2 % (p <0.001). These parameters were well maintained during the follow-up period with a mild, tolerant loss of correction. Neurological function and pain were significantly improved without deterioration. Age, pre-A/P and pre-AVH < 50 % influenced kyphosis recurrence (p = 0.032, 0.026, 0.011, respectively). CONCLUSIONS: Short-segment pedicle instrumentation including the fractured vertebra was effective in treating thoracolumbar burst fractures. The loss of correction at follow-up after implant removal was associated with age, A/P ratio and anterior vertebral height < 50 %.