Band Modification and Localized Lattice Engineering Leads to High Thermoelectric Performance in Ge and Bi Codoped SnTe-AgBiTe2 Alloys.

SnTe, emerging as an environment-friendly alternative to conventional PbTe thermoelectrics, has drawn significant attention for clean energy conversion. Here, a high peak figure of merit (ZT) of 1.45 at 873 K in Ge/Bi codoped SnTe-AgBiTe2 alloys is reported. It is demonstrated that the existence of Ge, Bi, and Ag facilitate band convergence in SnTe, resulting in remarkable enhancement of Seebeck coefficient and power factor. Simultaneously, localized lattice imperfections including dislocations, point defects, and micro/nanopore structures are caused by incorporation of Ge, Bi, and Ag, which can effectively scatter heat carrying phonons with different wavelengths and contribute to an extremely low κL of 0.61 W m-1  K-1 in Sn0.92 Ge0.04 Bi0.04 Te-10%AgBiTe2 . Such high peak ZT is achieved by decouples electron and phonon transport through band modification and localized lattice engineering, highlighting promising solutions for advancing thermoelectrics.

Multisegment transforaminal lumbar interbody fusion (TLIF) combined with Ponte osteotomy in degenerative lumbar scoliosis (DLS) surgery: a minimum of five years' follow-up.

PURPOSE: To evaluate the long-term clinical outcomes of degenerative lumbar scoliosis (DLS) with the administration of multisegment transforaminal lumbar interbody fusion (TLIF) combined with Ponte osteotomy long-level fixation fusion, as well as to identify the factors affecting health-related quality of life (HRQOL). METHODS: This was a retrospective single-centre study involving comprehensive clinical data. The Oswestry Disability Index (ODI), visual analog scale (VAS) outcomes, and Scoliosis Research Society (SRS-22) questionnaire were recorded to assess HRQOL. A correlation analysis was performed to determine the association between HRQOL and radiographic parameters. RESULTS: A total of 41 consecutive patients (15 males and 26 females) met the inclusion criteria with a follow-up of 8.62 ± 1.20 years. Factors associated with HRQOL were significantly improved post-operation. Global sagittal parameters, including the sagittal vertebral axis (SVA) and T1 pelvic angle (TPA), and local parameters, including apical vertebral translation (AVT) and apical vertebral rotation (AVR), were significantly improved at the last follow-up. Significantly strong correlations between each clinical and radiographic parameter were demonstrated. Moreover, a multiple linear regression analysis demonstrated that the differences in AVT and AVR were significantly correlated with the difference in lumbar lordosis (LL), which was significantly correlated with the differences in SVA and TPA. CONCLUSION: The surgical treatment of DLS with multisegment TLIF accompanied by Ponte osteotomy and long-level fixations improved the quality of life of patients with a long-term effect. AVR correction is an important factor for LL restoration that significantly correlates with improvements in the sagittal balance parameters SVA and TPA, which are key factors for guaranteeing good HRQOL.

NeuroRegen Scaffolds Combined with Autologous Bone Marrow Mononuclear Cells for the Repair of Acute Complete Spinal Cord Injury: A 3-Year Clinical Study.

Spinal cord injury (SCI) remains among the most challenging pathologies worldwide and has limited therapeutic possibilities and a very bleak prognosis. Biomaterials and stem cell transplantation are promising treatments for functional recovery in SCI. Seven patients with acute complete SCI diagnosed by a combination of methods were included in the study, and different lengths (2.0-6.0 cm) of necrotic spinal cord tissue were surgically cleaned under intraoperative neurophysiological monitoring. Subsequently, NeuroRegen scaffolds loaded with autologous bone marrow mononuclear cells (BMMCs) were implanted into the cleaned site. All patients participated in 6 months of rehabilitation and at least 3 years of clinical follow-up. No adverse symptoms associated with stem cell or functional scaffold implantation were observed during the 3-year follow-up period. Additionally, partial shallow sensory and autonomic nervous functional improvements were observed in some patients, but no motor function recovery was observed. Magnetic resonance imaging suggested that NeuroRegen scaffold implantation supported injured spinal cord continuity after treatment. These findings indicate that implantation of NeuroRegen scaffolds combined with stem cells may serve as a safe and promising clinical treatment for patients with acute complete SCI. However, determining the therapeutic effects and exact application methods still requires further study.

Single-stage posterior total en bloc spondylectomy in the treatment of lumbar spinal metastases.

OBJECTIVE: To report the clinical and radiographic outcomes of single-stage posterior total en bloc spondylectomy (TES) of lumbar spinal metastases. PATIENTS AND METHODS: From January 2012 to January 2015, 20 consecutive cases with lumbar spinal metastases who received single-stage posterior TES were retrospectively analyzed. A visual analog scale (VAS) was used to evaluate patients' pain status, American Spinal Injury Association (ASIA) classification was used to evaluate neurological status, and Eastern Cooperative Oncology Group (ECOG) score system was used to evaluate patients' performance status at pre- and post-operation and final follow-up. In addition, Intraoperative blood loss, operative time, postoperative complications, local kyphosis angle, and the postoperative duration of hospital stay were analyzed. RESULTS: The median follow-up time was 16 months (ranging from 3 to 39 months), and 4 patients were still alive at the last follow-up. The mean amount of intraoperative blood loss and operation time was 970 mL and 232.5 min, respectively. The average VAS score improved from 7.5 preoperative to 2.8 postoperative and 3.2 at the last follow-up. Postoperative complications occurred in 3 cases. Sixteen patients died within 2 years after surgery, 10 of which died within 1 year. In the remaining 4 patients, the mean follow-up period was 37.25 months. One case of local recurrence occurred but no implant failure presented during follow-up. CONCLUSIONS: Single-stage posterior TES is a challenging but rewarding procedure in the treatment of lumbar spinal metastases. Due to unique anatomy and biomechanics, surgeons should be aware of important vessels, and nerve root injury should be avoided.

[Risk factors analysis of coronal imbalance after posterior long-level fixation and transforaminal lumbar interbody fusion for degenerative lumbar scoliosis].

OBJECTIVE: To explore the risk factors of coronal imbalance after posterior long-level fixation and fusion for degenerative lumbar scoliosis. METHODS: Retrospectivly analyzed the clinical records of 41 patients with degenerative lumbar scoliosis who had received posterior long-level fixation and fusion with selective transforaminal lumbar interbody fusion (TLIF) accompanied by Ponte osteotomy between August 2011 and July 2016. Patients were divided into imbalance group (group A, 11 cases) and balance group (group B, 30 cases) according to state of coronal imbalance measured at last follow-up. The radiographic parameters at preoperation and last follow-up were measured, and the variance of preoperative and last follow-up parameters were calculated. The radiographic parameters included coronal Cobb angle, coronal balance distance (CBD), apical vertebral translation (AVT), apical vertebral rotation (AVR), Cobb angle of lumbar sacral curve (LSC), and L 5 tilt angle (L 5TA). Univariate analysis was performed for the factors including gender, age, preoperative T value of bone mineral density, number of instrumented vertebra, upper and lower instrumented vertebra, segments of TLIF, decompression, and Ponte osteotomy, as well as the continuous variables of preoperative imaging parameters with significant difference were converted into two-category variables, obtained the influence factors of postoperative coronal imbalance. Multivariate logistic regression analysis was performed to verify the risk factors from the preliminary screened influence factors and the variance of imaging parameters with significant difference between the two groups. RESULTS: The follow-up time of groups A and B was (3.76±1.02) years and (3.56±1.03) years respectively, there was no significant difference between the two groups ( t=0.547, P=0.587). The coronal Cobb angle, AVT, LSC Cobb angle, and L 5TA in group A were significantly higher than those in group B before operation ( P<0.05), and all the imaging parameters in group A were significantly higher than those in group B at last follow-up ( P<0.05). There was no significant difference between the two groups in parameters including the variance of coronal Cobb angle, AVT, and LSC Cobb angle before and after operation ( P>0.05), and there were significant differences between the two groups in parameters including the variance of CBD, L 5TA, and AVR ( P<0.05). Univariate analysis showed that preoperative L 5TA was the influencing factor of postoperative coronal imbalance ( P<0.05). Multivariate logistic regression analysis showed that preoperative L 5TA≥15° was an independent risk factor of postoperative coronal imbalance, and variance of pre- and post-operative AVR was a protective factor. CONCLUSION: Preoperative L 5TA≥15° is an independent risk factor for coronal imbalance in patients with degenerative lumbar scoliosis after posterior long-level fixation and fusion.