Comparison of clinical outcomes of expansive open-door laminoplasty with unilateral or bilateral fixation and fusion for treating cervical spondylotic myelopathy: a multi-center prospective study.

BACKGROUND: The present study evaluated the clinical outcomes and safety of expansive open-door laminoplasty, when securing with C4 - C6 lateral mass screw and fusion. METHODS: A total of 110 patients with cervical spondylotic myelopathy (CSM) were enrolled. There were 88 male and 22 female, with mean age at 60.55 ± 10.95 years. All of the patients underwent expansive open-door laminoplasty with unilateral or bilateral C4-6 lateral mass screws fixation and fusion. Clinical data, including age, gender, operation-related information, pre- and post-operation Japanese Orthopedic Association (JOA) scores, and cervical curvatures were collected. RESULTS: The mean follow-up time of the cohort was 13.61 ± 9.53 months. Among the 110 patients, 33 of them were allocated to Unilateral group, and 77 of them were in Bilateral group. The mean JOA score of the 110 patients before surgery was 10.07 ± 2.39, and the score was improved significantly to 12.85 ± 2.45 after surgery. There were no reported cases of neurological deterioration or symptom worsening. Patients in both the Unilateral group and Bilateral groups had significant improvement of JOA scores. Among all patients, the most frequently observed complications were axial symptoms (n = 7). The average preoperative cervical curvature among all patients was 15.17 ± 5.26, and the post-surgery curvature was 14.41 ± 4.29. Similar observations were found between Unilateral and Bilateral groups. CONCLUSION: The modified surgical approach provided satisfactory clinical outcome in patients with CSM. The unilateral and bilateral fixation appeared to provide similar outcomes, in terms of cervical curvature maintenance and improvement of clinical symptoms. However, the examination of the exact differences between the two fixation methods await further biomechanical studies.

Potential roles of microRNAs and their target genes in human multiple myeloma.

OBJECTIVES: The etiology of multiple myeloma (MM) is unknown and it remains incurable. We sought to elucidate the mechanisms underlying miRNAs involvement in MM pathogenesis. METHODS: Public mRNA and miRNA expression datasets for MM were collected from the Gene Expression Omnibus database. By integrated bioinformatics analysis, the expression signatures were identified and the miRNA-mRNA interaction network was constructed. The potential functions of target genes were then explored by functional enrichment analysis. RESULTS: Totally, 839 differentially expressed mRNAs and six differentially expressed miRNAs were identified. The context of miRNAs-mediated genes regulatory network consisted of 288 possible miRNA-mRNA target pairs. The hub miRNA was hsa-miR-92a, which can serve as the indicator for MM disease status. Another miRNA, hsa-miR-148a, could be useful for prognosis of MM. Functional annotation revealed that the miRNA targets may play important roles in viral infection and proteasome. Moreover, miRNA targets may be involved in renal cell carcinoma and other nervous system disease such as Huntington's disease, Alzheimer's disease and Parkinson's disease, which may be subsequent complications of MM. CONCLUSIONS: Infections could be a leading cause for the morbidity of MM patients. The crucial protein degradation machinery may be essential in the pathogenesis of MM.

[Separation of Chlorophyll Fluorescence from Scattering Light of Algal Water Based on the Polarization Technique].

Once chlorophyll molecules within the planktonic algae cells absorb light energy, they will release energy in the form of chlorophyll fluorescence emission. The elastic scattering light of particles in water is partially polarized, while chlorophyll fluorescence is unpolarized, so we can use the properties to separate the fluorescence signal from total scattering spectra for further retrieval the concentration of chlorophyll. But for coastal waters, the approach feasibility is still unclear. Based on this, we conducted the experiment in laboratory to analyze the influence of different concentrations of inorganic particles (IOP) and chlorophyll on the fluorescence extraction using polarization discrimination technique. The results indicate that, for algae water with different concentrations of IOP, the fluorescence peak will decrease while the concentration increase, but the retrieval result is still reliable when the concentration up to 300 mg·L(-1). For algae water with different concentrations of chlorophyll, the concentration of chlorophyll more higher, the efficiency of extracted fluorescence using polarization method is better, for common water, this approach can still work. The study proves that the polarization method is also applicable for complex water; it is of great importance for further detecting the concentration of chlorophyll in coastal waters using remote sensing.

[Effects of posterior lumbar spinal fusion on the stability of unstable lumbar segment and biomechanical properties of adjacent segments: a finite element study].

OBJECTIVE: To explore the effects of posterolateral lumbar fusion (PLF) and posterior lumbar interbody fusion (PLIF) on the stability of postoperative unstable single lumbar segment and the biomechanical alterations of the adjacent segments. METHODS: A finite element model of L3-S1 segments with a single segmental degeneration at the L4-5 level was established, and the model of L4-5 segmental instability after posterior laminectomy and facetectomy was also established, in which laminar and interior 2/3 area of bilateral facet joints were resected. Physical loads were applied to the models and the changes of the range of motion (ROM) at L4-5 level in different models were recorded at the condition of flexion, extension, lateral bending and rotation. PLF and PLIF were performed on postoperative unstable model respectively, the changes of the ROM at L4-5 level, the ROM and the stress on the adjacent discs in different models were recorded. RESULTS: Compared to the unstable model, the L4-5 segmental stability was restored after PLF or PLIF. The ROMs of L3-4 and L5-S1 levels were similar to the preoperative unstable model. The stress on adjacent discs (L3-4 and L5-S1) was increased significantly, and maximum stress distribution changed and concentrated in the anterior annulus fiber in the two fusion models. There was no significant difference of the maximum stress on adjacent discs between PLF and PLIF models [(1.056 ± 0.061) mPa vs (1.070 ± 0.075) mPa; (1.147 ± 0.055) mPa vs (1.162 ± 0.075)mPa, P>0.05]. CONCLUSIONS: Lumbar segmental stability after posterior laminectomy and facetectomy can be recovered by both PLF and PLIF. Both PLF and PLIF may increase the possibility of adjacent segment degeneration because of the augmentation of maximum stress on adjacent discs.

[Investigation of osteoporosis prevalence and osteoporosis-related clinical risk factors among healthy elderly male].

OBJECTIVE: To investigate the osteoporosis prevalence and osteoporosis-related clinical risk factors among healthy elderly male. METHODS: A cross-sectional study was conducted from January 2014 to October 2014. Healthy elderly male aged 50 and above from Beijing WangZuo Community who had completed the questionnaire we made were enrolled in this study and accepted bone mineral density (BMD) testing by dual energy X-ray absorptiometry. Subjects were classified as the osteoporosis group (OP group) and the non-osteoporosis group (Non-OP group) according to the WHO criteria, of which osteoporosis was defined arbitrarily when any T-score was -2.5 standard deviations or less at femoral neck, total hip or lumbar spine (L1-4). The clinical risk factors of each subject including age, body weight, Body Mass Index (BMI), previous fragility fracture history, smoking, alcohol abuse, glucocorticoid therapy and other capable clinical risk factors were collected and compared in OP group and Non-OP group. RESULTS: In the 346 cases of elderly healthy men, 18.5% had osteoporosis, 55.5% had osteopenia and 26.0% were normal. Femoral neck's and total hip's BMD level decreased with increasing age. However, the trend was not found at lumbar spine site. There appeared to be a significant difference in BMD standard between lumbar vertebral and total hip when compared with age-matched cohorts (P<0.05). Weight, BMI, previous fragility fracture history and smoking were found significant differences between OP group and Non-OP group (P<0.05). CONCLUSIONS: The prevalence of osteoporosis in healthy older men should not be ignored. Low BMI and weight, previous fragility fracture history and smoking history were clinical risk factors of OP in this population.

SWAP-Assembler: scalable and efficient genome assembly towards thousands of cores.

BACKGROUND: There is a widening gap between the throughput of massive parallel sequencing machines and the ability to analyze these sequencing data. Traditional assembly methods requiring long execution time and large amount of memory on a single workstation limit their use on these massive data. RESULTS: This paper presents a highly scalable assembler named as SWAP-Assembler for processing massive sequencing data using thousands of cores, where SWAP is an acronym for Small World Asynchronous Parallel model. In the paper, a mathematical description of multi-step bi-directed graph (MSG) is provided to resolve the computational interdependence on merging edges, and a highly scalable computational framework for SWAP is developed to automatically preform the parallel computation of all operations. Graph cleaning and contig extension are also included for generating contigs with high quality. Experimental results show that SWAP-Assembler scales up to 2048 cores on Yanhuang dataset using only 26 minutes, which is better than several other parallel assemblers, such as ABySS, Ray, and PASHA. Results also show that SWAP-Assembler can generate high quality contigs with good N50 size and low error rate, especially it generated the longest N50 contig sizes for Fish and Yanhuang datasets. CONCLUSIONS: In this paper, we presented a highly scalable and efficient genome assembly software, SWAP-Assembler. Compared with several other assemblers, it showed very good performance in terms of scalability and contig quality. This software is available at: https://sourceforge.net/projects/swapassembler.

[Association of body mass index and male primary osteoporosis].

OBJECTIVE: To explore the association between body mass index (BMI) and male primary osteoporosis (OP) in a Chinese Han population. METHODS: The association of BMI with OP was assessed in 276 Chinese healthy aged males for physical examination. They were classified into OP, osteopenia and normal groups according to the World Health Organization (WHO) criteria, i.e. OP was defined arbitrarily when any T-score was -2.5 standard deviations or less at femoral neck, total hip or lumbar spine (L1-4) site. We also classified the subjects as different BMI groups of low weight, normal weight, overweight and obesity. The prevalence of OP was compared among different BMI groups. We determined the sensitivity, specificity and area under the curve of receiver operating characteristic (ROC) for validating the valuation of BMI to predict male primary OP. RESULTS: Among them, 6/12 had OP in the low weight group, 17.36% (21/121) in the normal group and 12.59% (18/143) in the overweight and obesity group. And the difference was significant. The analysis of ROC curve showed that BMI was of limited value in predicting OP (P > 0.05). CONCLUSION: BMI has a positive correlation with male OP. The value of BMI is limited for predicting OP in males. And the relevant factors associated with male OP should to be further studied.

Molecular dynamics study of carbon nanotube as a potential dual-functional inhibitor of HIV-1 integrase.

HIV-1 integrase (IN) plays an important role in integrating viral DNA into human genome, which has been considered as the drug target for anti-AIDS therapy. The appearance of drug-resistance mutants urgently requires novel inhibitors that act on non-active site of HIV-1 IN. Nanoparticles have such unique geometrical and chemical properties, which inspires us that nanoparticles like nanotubes may serve as better HIV-1 IN inhibitors than the conventional inhibitors. To test this hypothesis, we performed molecular dynamics (MD) simulation to study the binding of a carbon nanotube (CNT) to a full-length HIV-1 IN. The results showed that the CNT could stably bind to the C-terminal domain (CTD) of HIV-1 IN. The CNT also induced a domain-shift which disrupted the binding channel for viral DNA. Further MD simulation showed that a HIV-1 IN inhibitor, 5ClTEP was successfully sealed inside the uncapped CNT. These results indicate that the CNT may serve as a potential dual-functional HIV-1 IN inhibitor, not only inducing conformation change as an allosteric inhibitor but also carrying small-molecular inhibitors as a drug delivery system.

Gene set analysis in the cloud.

UNLABELLED: Cloud computing offers low cost and highly flexible opportunities in bioinformatics. Its potential has already been demonstrated in high-throughput sequence data analysis. Pathway-based or gene set analysis of expression data has received relatively less attention. We developed a gene set analysis algorithm for biomarker identification in the cloud. The resulting tool, YunBe, is ready to use on Amazon Web Services. Moreover, here we compare its performance to those obtained with desktop and computing cluster solutions. AVAILABILITY AND IMPLEMENTATION: YunBe is open-source and freely accessible within the Amazon Elastic MapReduce service at s3n://lrcv-crp-sante/app/yunbe.jar. Source code and user's guidelines can be downloaded from http://tinyurl.com/yunbedownload.

SOAP3: ultra-fast GPU-based parallel alignment tool for short reads.

SOAP3 is the first short read alignment tool that leverages the multi-processors in a graphic processing unit (GPU) to achieve a drastic improvement in speed. We adapted the compressed full-text index (BWT) used by SOAP2 in view of the advantages and disadvantages of GPU. When tested with millions of Illumina Hiseq 2000 length-100 bp reads, SOAP3 takes < 30 s to align a million read pairs onto the human reference genome and is at least 7.5 and 20 times faster than BWA and Bowtie, respectively. For aligning reads with up to four mismatches, SOAP3 aligns slightly more reads than BWA and Bowtie; this is because SOAP3, unlike BWA and Bowtie, is not heuristic-based and always reports all answers.

Validation of an osteoporosis self-assessment tool to identify primary osteoporosis and new osteoporotic vertebral fractures in postmenopausal Chinese women in Beijing.

BACKGROUND: This study aimed to validate the effectiveness of the Osteoporosis Self-assessment Tool for Asians (OSTA) in identifying postmenopausal women at increased risk of primary osteoporosis and painful new osteoporotic vertebral fractures in a large selected Han Chinese population in Beijing. METHODS: We assessed the performance of the OSTA in 1201 women. Subjects with an OSTA index > -1 were classified as the low risk group, and those with an index ≤ -1 were classified as the increased risk group. Osteoporosis is defined by a T-score ≤ 2.5 standard deviations according to the WHO criteria. All painful, new vertebral fractures were identified by X-ray and MRI scans with correlating clinical signs and symptoms. We determined the sensitivity, specificity, and area under the receiver operating characteristic (ROC) curve for correctly selecting women with osteoporosis and painful new vertebral fractures. RESULTS: Of the study subjects, 29.3% had osteoporosis, and the prevalence of osteoporosis increased progressively with age. The areas under the ROC curves of the OSTA index (cutoff = -1) to identify osteoporosis in the femoral neck, total hip, and lumbar spine were 0.824, 0.824, and 0.776, respectively. The sensitivity and specificity of the OSTA index (cutoff = -1) to identify osteoporosis in healthy women were 66% and 76%, respectively. With regard to painful new vertebral fractures, the area under the ROC curve relating the OSTA index (cutoff = -1) to new vertebral fractures was 0.812. CONCLUSIONS: The OSTA may be a simple and effective tool for identifying the risk of osteoporosis and new painful osteoporotic vertebral fractures in Han Chinese women.

Application of 5G technology to conduct tele-surgical robot-assisted laparoscopic radical cystectomy.

BACKGROUND: The aim of this study was to test the effectiveness, safety and stability of the 5G communication technology in clinical laparoscopic telesurgery. METHODS: An ultra-remote radical cystectomy (network communication distance of nearly 3000 km) was performed on patient diagnosed with T2N0M0 stage bladder cancer using a domestically produced "MicroHand" surgical robot. RESULTS: The network delay, operative time, blood loss, intraoperative complications, postoperative recovery, and hospitalisation time were recorded. The 5G network was used throughout the operation, with an average total delay of 254 ms. The operation went well and the patient recovered smoothly. CONCLUSIONS: Ultra-remote clinical laparoscopic surgery can be performed safely and smoothly. More importantly, our model can provide insights for promoting the future development of telesurgery in China.

[Biomechanical effect on adjacent vertebra after percutaneous kyphoplasty with cement leakage into disc: a finite element analysis of thoracolumbar osteoporotic vertebral compression fracture].

OBJECTIVE: To explore the biomechanical effects on adjacent vertebra of thoracolumbar osteoporotic vertebral compression fracture (OVCF) after percutaneous kyphoplasty (PKP) with cement leakage into the disc by using finite element analysis. METHODS: T10-L2 segment data were obtained from computed tomography (CT) scans of an elder female with single T12 OVCF undergoing a cement leakage into the T12-L1 disc after PKP. A three-dimensional finite element Model of thoracolumbar spine (T10-L2) was built in the Mimics and the ABAQUS software. The stress on annulus fiber, nucleus pulposus, endplate and facet joints under axial pressure (0.3, 1.0, 4.0 MPa) were analyzed. RESULTS: The 3D finite element after percutaneous kyphoplasty (PKP) with cement leakage into the disc may be strongly related with the changes of biomechanical effects on adjacent vertebra of thoracolumbar OVCF. Models of thoracolumbar OVCF before and after PVP with a cement leakage into the T12-L1 disc were successfully established. The stresses increased with a rising axial pressure in the model of cement leakage into the disc after PVP, the stress augmentation scope on adjacent end plates(T11 low plate & L1 top plate) and intervertebral disc (T11-12 & T12-L1) increased. The maximal Von Mises stress on adjacent vertebra (T11 & L1) increased while but the maximal Von Mises stress on end vertebra (T10 & L2) decreased. CONCLUSION: Postoperative adjacent vertebral fracture.

A New Molecular Recognition Concept: Multiple Hydrogen Bonds and Their Optically Triggered Proton Transfer in Confined Metal-Organic Frameworks for Superior Sensing Element.

We report a new sensing mechanism based on an indium-dihydroxyterephthalic acid metal-organic framework (MOF, SNNU-153), in which the spatially fitted analyte-MOF hydrogen-bond (H-bond) formation provides selective recognition while the analyte-H-bond assisted excited-state intramolecular proton transfer (ESIPT) and the resulting ratiometric emission act as a superior signal transducer with ultrafast response. The synergy of ESIPT signal transduction and confined MOF pore enables the SNNU-153 sensor selectively sensing hydrazine even among nitrogen-containing hydride analogs such as NH3, NH2OH, and (Me)2NNH2. The key of H-bond and associated ESIPT was further counter evidenced by an indium-2,5-dimethoxyterephthalic acid MOF (SNNU-152), where the hydroxyl protons were removed by methylation, showing near inertness to N2H4. The new molecular recognition concept thus makes SNNU-153 a powerful N2H4 sensor, which should be far-reaching to other sensing elements.

[Three-dimensional finite element model of thoracolumbar spine with osteoporotic vertebral compression fracture].

OBJECTIVE: To build a three-dimensional finite element model of thoracolumbar spine with osteoporotic vertebral compression fracture (OVCF) and analyze its biomechanical change. METHODS: The T10-L2 segment data were obtained from computed tomography (CT) scans of an elderly female with a single T12 OVCF. A three-dimensional finite element model of thoracolumbar spine was constructed with the MIMICS and ABAQUS software. The model was composed of bony vertebrae, articulating facets, intervertebral disc and associated ligaments. The basic stress analysis of T10-L2 motion segment was made for different material properties of bone, ligaments and facet joints contacting frictional property. The stress on the annulus fiber, nucleus pulposus, endplate and facet joints under axial pressure (0.3 MPa, 1.0 MPa, 4.0 MPa) were analyzed. RESULTS: A three-dimensional finite element model of human T12-L2 motion segment had 617468 elements. And the stress was higher in vertebral body than posterior structure. The distribution of pressure stresses in intervertebral disc was asymmetrical. The stress increased with a rising axial pressure. CONCLUSION: 3D finite element model of thoracolumbar OVCF and adjacent segments are successfully established. The results of stress analysis are both feasible and reliable.

The nitrogen edge-doped effect on the static first hyperpolarizability of the supershort single-walled carbon nanotube.

The nitrogen edge-doped effect on the structure, dipole moment, and first hyperpolarizability of the supershort single-walled carbon nanotube (5, 0) has been studied systematically. For the nitrogen edge-doped effect on the structure, the mean diameter on the nitrogen-doped side (D(u)) decreases as the number of doped-nitrogen (n) increases (4.044 (1) > 3.991 (2) > 3.941 (3) > 3.891 (4) > 3.844 A (5)). Significantly, the nitrogen edge-doped effects on the dipole moment and first hyperpolarizability are revealed for the first time and these new effects are dramatic for the supershort single-walled carbon nanotube (5, 0). Among the beta(0) values of these seven nitrogen-doped structures, the largest beta(0) (3155 au) is larger by almost 450 times than the very small beta(0) (7 au) of undoped structure (D(5h)). For nitrogen-doped structures, the order of the beta(0) values is 3155 (1) > 2677 (2A) approximately 2817 (2B) > 1465 (3A) approximately 1458 (3B) > 670 (4) > 254 au (5), which shows two interesting relationships between the beta(0) value and nitrogen-doped number: (1) the smaller the nitrogen-doped number, the larger the beta(0) value. (2) The structures with the same number of doped-nitrogen have almost the same beta(0) values (1465 for 3A and 1458 au for 3B). As for the frequency-dependent beta (-omega; omega, 0) and beta (-2omega; omega, omega), the dependence on the nitrogen-doped number (n) is similar to the case of static beta(0). For beta (-2omega; omega, omega) values at omega = 0.005 au are 3220 (1) > 2720 (2A) approximately = 2862 (2B) > 1480 (3A) approximately = 1477 (3B) > 676 (4) > 256 au (5). In addition, the important monotonic dependences of the beta value on the D(u) and electronic spatial extent are also observed. The new knowledge of influence the beta value will be beneficial to design high-performance nonlinear optical (NLO) materials.

Structures and considerable static first hyperpolarizabilities: new organic alkalides (M+@n6adz)M'- (M, M'=Li, Na, K; n=2, 3) with cation inside and anion outside of the cage complexants.

Eighteen structures of new organic alkalides (M+@n6adz)M'- (M, M'=Li, Na, K; n=2, 3) with the alkali-metal cation M+ lying near the center of the adz cage and the alkali-metal anion M'- located outside are obtained with all real frequencies. They exhibit very large static first hyperpolarizabilities (beta0) up to 3.2x10(5) au, which exceeds the record value of beta0=1.7x10(5) au for nonlinear optical compounds [Chem.-Eur. J. 1997, 3, 1091]. All potassides (M+@n6adz)K- (M=Li, Na, K; n=2, 3) have considerably large beta0 values (1.6x10(5)-3.2x10(5) au) much larger than the beta0 value (3.6x10(4) au) of the previously designed cuplike alkalide Li+(calix[4]pyrrole)K- [J. Am. Chem. Soc. 2006, 128, 1072]. This shows that the 26adz and 36adz cage complexants are preferable to cuplike calix[4]pyrrole complexant in enhancing the first hyperpolarizability. The effect of cage size of the complexant on the first hyperpolarizability is also presented here: in most cases, the smaller cage complexant corresponds to the larger beta0 value. Moreover, the crucial role by the alkali-metal anion in the large first hyperpolarizability of these alkalides is revealed. These results may provide new means for designing high-performance nonlinear optical materials.

Indication for hypertrophy posterior longitudinal ligament removal in anterior decompression for cervical spondylotic myelopathy.

The retrospective study aimed to investigate the indication for hypertrophy posterior longitudinal ligament (HPLL) removal in anterior decompression for cervical spondylotic myelopathy (CSM). A total of 138 consecutive patients with CSM were divided into 2 groups with developmental cervical stenosis (DCS) (group S) and non-DCS (group N), according to the Pavlov ratio. These 2 groups were subdivided into 2 further subgroups, according to whether HPLL was removed or preserved: group SR (49 patients) and group SP (32 patients) in group S, group NR (21 patients) and group NP (36 patients) in group N. The modified Japanese Orthopedic Association score (mJOA), the modified recovery rate (mRR), quality of life (QoL), and relevant clinical data were used for clinical and radiological evaluation. The mJOA scores improved from 7.3 ±â€Š2.2 to 15.0 ±â€Š1.8 in the SR group and from 7.9 ±â€Š2.3 to 14.2 ±â€Š1.5 in the SP group (P = .036), with postoperative QoL significantly higher in the SR group than the SP group. A reduction in the diameter of enlarged spinal canals occurred at a significantly faster rate in the SP group compared with the SR group (P = .002). Multivariate regression analyses showed removal of HPLL correlated with mJOA scores (coefficient = 7.337, P = .002), mRR (%) (coefficient = 9.117, P = .005), PCS (coefficient = 12.129, P < .001), and MCS (coefficient = 14.31, P < .001) in the S group at 24 months postoperatively, while removal of HPLL did not correlate with clinical outcomes in the N group. The HPLL should, therefore, be removed when mobility was reduced and the spinal cord remained compressed after anterior decompression procedures in the patients with DCS. However, in non-DCS patients, it remains unclear as to whether removal of HPLL provides any clinical benefit, thus, HPLL removal may not be necessary.

A comparative theoretical study on the electrical and nonlinear optical properties of Li atom adsorbed on AlN and BN single-walled nanotubes.

The geometrical structures, electrical properties, and nonlinear optical (NLO) properties of AlNNT-Li and BNNT-Li nanotube systems were investigated by means of the density functional theory (DFT) method. Frontier molecular orbitals and density of states analyses show that adsorption of the Li atom can significantly narrow the wide HOMO-LUMO gaps of pure AlNNT and BNNT. The results reveal that AlNNT-Li and BNNT-Li systems containing diffuse excess electrons can be regarded as inorganic electrides. The formation of diffuse excess electrons leads to a decrease in transition energies, thereby increasing the first hyperpolarizabilities (ß 0) of AlNNT-Li and BNNT-Li. This work may contribute to the development of potential high-performance NLO materials. Graphical abstract The structural characteristics and nonlinear optical properties of the AlNNT-Li and BNNT-Li systems were studied by means of density functional theory. Introduction of Li atoms greatly enhances the static first hyperpolarizabilities of AlNNT-Li and BNNT-Li.

A Novel Approach for Percutaneous Vertebroplasty Based on Preoperative Computed Tomography-Based Three-Dimensional Model Design.

OBJECTIVE: To describe a new technique for the efficient use of preoperative planning based on preoperative computed tomography-based three-dimensional (3D) model design for percutaneous vertebroplasty (PVP) in a patient with osteoporotic vertebral compression fracture. METHODS: A 76-year-old woman with acute osteoporotic vertebral compression fracture (L1 level) accepted a novel precise PVP. A 3D model of thoracolumbar vertebrae (T12-L2) based on preoperative computed tomography scanning data and a simulative PVP (via a bilateral transpedicular approach) were built in MIMICS (Materialise Interactive Medical Image Control System) software. With the help of 3 radiopaque markers located at the skin of the back and preoperative digital design by MIMICS, bilateral skin entry points, needles direction including abduction angle and head inclination angle, and needle insertion depth were established. RESULTS: During surgery, only 1 shot of fluoroscopy was required to confirm the skin entry points. The operation took only about 23 minutes and total patient exposure dose was 4.5 mSv. The intraoperative radiologic results showed that the cement distribution in the L1 vertebra was good without any puncture-related complications. The patient's visual analog scale score improved from 9 points preoperatively to 2 points postoperatively. The patient's preoperative Oswestry Disability Index score was 80 points, which improved to 57.8 points postoperatively. CONCLUSIONS: The novel precise PVP based on preoperative 3D model design allows 1) visualization of the morphology of the fractured vertebral body, 2) increased precision of puncture with decreasing incidence of puncture-related complications and reduced radiation exposure, and 3) less operation time, decreasing the learning curve of beginners with limited experience.