Exploration of microRNA-106b-5p as a therapeutic target in intervertebral disc degeneration: a preclinical study.

MicroRNA (miRNA) has emerge as a vital regulator in the pathogenesis of intervertebral disc degeneration (IDD). However, miR-106b-5p expression in the human nucleus pulposus (NP) and potential mechanisms remain to be elucidated. In this study, the aim was to verify the potential therapeutic mechanisms of miR-106b-5p for IDD. Key miRNAs were screened for in degenerative and normal human intervertebral disc samples. qRT-PCR and fluorescence in situ hybridization (FISH) were used to verify the miR-106b-5p differential expression. The targeting link between miR-106b-5p and Sirtuin 2 (SIRT2) was identified using the luciferase reporter assay and bioinformatics. Flow cytometry, EdU method, and cell scratching were all performed to determine the NP cell function and IDD models were constructed for in vivo experiments. SIRT2, MMP13, ADAMTS5, Col II, Aggrecan, Ras, ERK1/2, and p-ERK1/2 protein levels were assayed by western blotting. Overexpression of miR-106b-5p in NP cells decreased cell growth, induced apoptosis, hindered extracellular matrix formation, and increased the expression of matrix-degrading enzymes through the SIRT2/MAPK/ERK signaling pathway. Importantly, intradiscal delivery of antagomiR-106b-5p significantly attenuated IDD development. Our findings demonstrate that targeting miR-106b-5p in intervertebral disc has therapeutic effects on IDD.

Analysis of odontoid parameters in adolescent idiopathic scoliosis patients with different curve types.

Introduction: Odontoid incidence (OI) is an important parameter that has recently been developed. However, there are currently no studies on OI in adolescent idiopathic scoliosis (AIS) patients. We aimed to examine the significance of OI in describing cervical sagittal alignment in AIS patients, explore the differences in cervical sagittal parameters among these patients with different curve types, and investigate the correlations between coronal deformity and cervical sagittal parameters in AIS patients. Methods: The whole-spine anteroposterior and lateral plain radiographs of AIS patients were retrospectively analyzed. The parameters, including OI, odontoid tilt (OT), C2 slope, cervical lordosis (CL), T1 slope (T1S), and others, were measured. The AIS patients were grouped based on different curve types. Measurement parameters were compared between different groups. Pearson correlation analysis was performed for cervical sagittal parameters and Cobb angle. Results: Ninety AIS patients were included, consisting of 14 males and 76 females. The main thoracic curve group exhibited a smaller OI compared to the main thoracolumbar/lumbar curve group (P < 0.05). In the AIS patients with a main thoracic curve, there was a significant correlation between Cobb angle and OI (r = -0.371, p < 0.01). The odontoid parameters exhibited significant correlations with several classic cervical sagittal parameters in AIS patients with different curve types. The validation of the formula CL = 0.36 × OI-0.67 × OT-0.69 × T1S showed a significant correlation (correlation coefficient = 0.917) between the actual measurements and the predicted values, with a determination coefficient of 0.842. Conclusion: There may be a difference in OI between AIS patients with a main thoracic curve and those with a main thoracolumbar/lumbar curve. Odontoid parameters could be used to describe cervical sagittal alignment in AIS patients with different curve types.

Odontoid incidence: a constant cervical anatomical feature evident in standing plain radiographs and supine magnetic resonance images.

OBJECTIVE: To assess whether there is a difference between measurements of odontoid incidence (OI) and other cervical sagittal parameters by X-ray radiography and those by supine magnetic resonance imaging (MRI). METHODS: Standing X-ray and supine MRI images of 42 healthy subjects were retrospectively analyzed. Surgimap software was employed to measure cervical sagittal parameters including OI, odontoid tilt (OT), C2 slope (C2S), C0-2 angle, C2-7 angle, T1 slope (T1S) and T1S-cervical lordosis (CL). Paired samples t-test was applied to determine the difference between parameters measured by standing X-ray and those by supine MRI. In addition, the statistical correlation between the parameters were compared. The prediction of CL was performed and validated using the formula CL = 0.36 × OI - 0.67 × OT - 0.69 × T1S. RESULTS: Significant correlations and differences were found between cervical sagittal parameters determined by X-ray and those by MRI. OI was verified to be a constant anatomic parameter and the formula CL = 0.36 × OI - 0.67 × OT - 0.69 × T1S can be used to predict CL in cervical sagittal parameters. CONCLUSIONS: OI is verified as a constant anatomic parameter, demonstrating the necessity of a combined assessment of cervical sagittal balance by using standing X-ray and supine MRI. The formula CL = 0.36 × OI - 0.67 × OT - 0.69 × T1S can be applied to predict CL in cervical sagittal parameters.

Variation of Odontoid Incidence According to Age in Asymptomatic Children.

OBJECTIVE: To investigate the effect of age and sex on odontoid parameters and their relationships with cervical sagittal alignment in children. METHODS: A total of 155 Chinese children without cervical symptoms were divided into groups by age: 3-12 years (87 participants), 13-18 years (68 participants), and sex: male (91 participants) and female (64 participants). Lateral plain radiographs of the whole spine were analyzed for (1) odontoid parameters: odontoid incidence (OI), odontoid tilt, and C2 slope (C2S); and (2) cervical sagittal parameters: C0-2, C2-3, C2-4, C2-5, C2-6, and C2-7 angles (cervical lordosis [CL]), T1 slope (T1S), and T1S minus CL (T1S-CL). Student's t-tests, linear regression analyses, and Pearson's correlation coefficient analyses were performed. RESULTS: OI showed a significant difference between the 3-12 and 13-18 year groups (13.35°±4.32° vs. 17.21°±4.26°, P<0.001), and significant differences were also observed in odontoid tilt (P=0.001) and C2S (P<0.001) between different sexes. Positive correlations were found between age and OI in the 3-12 and 13-18 year groups (adjusted R2=0.104 and 0.048, respectively). OI and C2S were positively correlated with the C0-2 angle in all age and sex groups. CONCLUSIONS: Age emerged as a critical determinant of OI, which increased with age among pediatric populations. Clinicians should carefully consider the disparity in OI during the assessment and restoration of cervical sagittal balance in children.

Multiple microwave frequencies measurement based on stimulated Brillouin scattering with improved measurement range.

We numerically investigate the operational principle and performance of stimulated Brillouin scattering based multiple microwave frequency signals measurement. The unknown signals are processed specially to generate a gain region which is measured by phase modulation to amplitude modulation converting. By sweeping the vector network analyzer, both single and multiple frequencies measurement can be achieved. The loss spectrum generated by one of the pumps is fully compensated by the gain spectrum of the other pump, which increases the measurement range from 2νB to 4νB.

An ultrawide tunable range single passband microwave photonic filter based on stimulated Brillouin scattering.

A single passband microwave photonic filter with ultrawide tunable range based on stimulated Brillouin scattering is theoretically analyzed. Combining the gain and loss spectrums, tuning range with 44GHz is obtained without crosstalk by introducing two pumps. Adding more pumps, Tuning range multiplying with the multiplication factor equaling to the total quantity of pump can be achieved, which has potential application in microwave and millimeter wave wireless communication systems.

The Significance of Odontoid Incidence in Patients With Cervical Spondylotic Myelopathy.

STUDY DESIGN: Observational study. OBJECTIVE: To analyze the cervical sagittal parameters for standing Digital radiography (DR) and supine Magnetic resonance imaging (MRI), and to further clarify the relationship between odontoid incidence (OI) and cervical spondylotic myelopathy (CSM). METHODS: 52 CSM patients aged 54.46 ± 2.89 years underwent both standing DR and supine MRI scans of cervical spine between November 2021 and November 2022. OI, odontoid tilt (OT), C2 slope (C2S), T1 slope (T1S), C0-2 angle, C2-7 angle (cervical lordosis [CL]), and T1S-CL were measured in both DR and MRI images using Surgimap (Version 2.3.2.1). Pearson correlation and linear regression were used to compare these parameters between the two modalities. RESULTS: Cervical sagittal parameters, including OI, OT, C2S, C0-2 angle, T1S, C2-7 angle (CL) and T1S-CL, showed no significant differences in the measurements between the two modalities. Based on the DR images, OI was related to OT (r = .386, P < .01), C2S (r = .505, P < .01), CL (r = -.412, P < .01), and T1S-CL (r = .320, P < .05), and OI was matched with CL (r2 = .170) and T1S-CL (r2 = .102). Based on MRI images, OI was related to OT (r = .433, P < .01), C2S (r = .516, P < .01), CL (r = -.355, P < .01), and T1S-CL (r = .271, P < .05), and OI matched with C2-7 (r2 = .126) and T1S-CL (r2 = .073). CONCLUSION: OI is an independent parameter related to cervical anatomy and its measurement is unaffected by external factors. In patients with CSM, odontoid parameters may effectively describe the sagittal alignment of the cervical spine on DR and MRI images.

Scientific publications on orthopedic surgery from three major East Asian countries (2012-2021).

BACKGROUND: East Asia is the most dynamic region in the world and includes three major countries: Japan, South Korea and China. Due to rapid economic growth, orthopedics research in East Asia has achieved great advances during the past 10 years. However, the current status of orthopedic research in Japan, South Korea and China is still unclear. AIM: To understand the current status of orthopedic research in Japan, South Korea, and China. METHODS: Journals listed in the ''Orthopedics'' category of Science Citation Index Expanded subject categories were included. The PubMed and Web of Knowledge electronic databases were searched to identify scientific publications from the selected journals written by researchers from Japan, South Korea and China. A systematic analysis was conducted to analyze orthopedic research articles published in the three countries based on the number of articles, study design, impact factors (IFs) and citations. Furthermore, we also ranked the top 10 countries worldwide with the highest publications in the past 10 years. Additionally, we ranked the top 10 countries with the highest number of publications in the world in the past 10 years. Statistical analyses were performed using SPSS 20.0 software (SPSS Inc., Chicago, IL, United States), and statistical results are given in Tables and Figures. The Kruskal-Wallis test and the Mann-Whitney test were used to detect differences between countries. The tendency regarding the number of articles was analyzed by curvilinear regression. A two-tailed P < 0.05 was considered significant. RESULTS: From 2012-2021, a total of 144518 articles were published in the 86 selected orthopedic journals. During this period, the number of worldwide published orthopedic articles has shown an annual increasing trend. A total of 27164 orthopedic research articles were published by Japan, South Korea and China during the past 10 years; 44.32% were from China, 32.98% were from Japan, and 22.70% were from South Korea. From 2012 to 2021, the annual number of articles markedly increased in each of the three countries. Over time, the worldwide share of articles increased substantially in South Korea (3.37% to 6.53%, P < 0.001) and China (5.29% to 9.61%, P < 0.001). However, the worldwide share of articles significantly decreased in Japan (5.22% to 3.80%, P < 0.001). The annual total IFs of articles from China were well above those of articles from Japan and South Korea (36597.69 vs 27244.48 vs 20657.83, P < 0.05). There was no significant difference among the articles in the top 10 high-IF orthopedics journals published from those three countries [South Korea (800) > China (787) > Japan (646), P > 0.05]. CONCLUSION: Over the past 10 years, China's scientific publications in orthopedic journals have shown an increasing trend. Considering the relative scale of the populations, Japan and South Korea have outpaced China with respect to quality.

Ultraviolet photodetector with high internal gain enhanced by TiO2/SrTiO3 heterojunction.

In this letter, TiO2 nanocrystalline film was prepared on SrTiO3 (001) substrate to form an n-n heterojunction active layer. Interdigitated Au electrodes were deposited on the top of TiO2 film to fabricate modified HMSM (heterojunction metal-semiconductor-metal) ultraviolet photodetector. At 10 V bias, the dark current of the detector was only 0.2 nA and the responsivity was 46.1 A/W at 260 nm. The rise and fall times of the device were 3.5 ms and 1.4 s, respectively. The TiO2/SrTiO3 heterojunction contributed a lot to the high responsivity and reduced the fall time, which improved the device performance effectively. These results demonstrate the excellent application of TiO2/SrTiO3 heterojunction in fabricating high performance UV photodetectors.

Schottky barrier characteristics and internal gain mechanism of TiO2 UV detectors.

High-responsivity metal-semiconductor-metal TiO(2) UV photodetectors with Ni and Au electrodes were fabricated identically. Their Schottky barrier heights and photocurrent gain mechanism were studied. The effective barrier height Φ and ideality factor n were evaluated according to the thermionic emission theory. The result that Φ(Ni) was lower than Φ(Au) may be attributed to the electron transfer from Ni to the TiO(2) substrate, which would lead to a dipole layer and, accordingly, decrease the barrier height. In addition, the I-V characteristics of the Ni/TiO(2)/Ni and Au/TiO(2)/Au photodetectors were observed. A significant internal gain was obtained, and the mechanism of the internal gain was studied by the phototransistor model in detail.

Surgical resection of intradural extramedullary tumors in the atlantoaxial spine via a posterior approach.

BACKGROUND: The anatomical features of the atlantoaxial spine increase the difficulty of complete and safe removal of atlantoaxial intradural extramedullary (IDEM) tumors. Studies concerning surgical interventions via a posterior approach are limited. AIM: To investigate the safety and efficacy of atlantoaxial IDEM tumor resection using a one-stage posterior approach. METHODS: We retrospectively analyzed clinical databases for one-stage atlantoaxial IDEM tumor resection via a posterior approach between January 2008 and January 2018. The analyzed data included tumor position, histopathological type, pre- and post-operative Japanese Orthopedic Association (JOA) scores and Nurick grades, postoperative complication and recurrence status. RESULTS: A total of 13 patients who underwent C1-C2 Laminectomy and/or unilateral facetectomy via the posterior approach were enrolled in the study. In all cases reviewed, total tumor resection and concomitant C1-C2 fusion were achieved. The average follow-up was 35.3 ± 6.9 mo (range, 26-49 mo). A statistically significant difference was noted between the preoperative JOA score (11.2 ± 1.1) and the score at the last final follow-up (15.6 ± 1.0) (P < 0.05). A statistically significant difference was noted between the preoperative Nurick grade (2.3 ± 0.9) and that at the last follow-up (1.2 ± 0.4) (P < 0.05). However, no statistically significant difference was noted between the preoperative and last follow-up C1-2 Cobb angle and C2-7 Cobb angle (P > 0.05). No mortalities, severe complications or tumor recurrence were observed during the follow-up period. CONCLUSION: Total resection of atlantoaxial IDEM tumors is feasible and effective via a posterior approach. Surgical reconstruction should be considered to avoid iatrogenic kyphosis and improve spinal stability and overall clinical outcomes.

Photoelectric properties of TiO2-ZrO2 thin films prepared by sol-gel method.

Acidic sols of TiO2, ZrO2 and Ti-Zr mixed oxide precursors were prepared. The sols were then smeared on quartz substrate and annealed at 650 degrees C for 2 hour to form polycrystalline oxide films. XRD, SEM, UV-visible absorption spectra and XPS were carried out to characterize the films. It was found that the crystalline phase of pure titania is an anatase and pure zirconia is a tetragonal. The binary oxides show the anatase phase at the molar ratio of Ti:Zr = 2.73:1, which means that solid solution was formed. The absorption edge of the TiO2-ZrO2 binary oxides showed obvious blue shift as the Zr ratio increased. The results obtained indicate that the band gap of the binary oxides could be adjusted from 3.2 eV (TiO2) to 7.8 eV (ZrO2) by varying the molar ratio of Ti and Zr. Au interdigitated electrodes were produced by planar technology and MSM (metal-semiconductor-metal) structure UV detector based on TiO2-ZrO2 binary oxides was fabricated. Obvious photoelectric response was observed.

Design of a vector-sum integrated microwave photonic phase shifter in silicon-on-insulator waveguides.

An orthogonal vector-sum integrated microwave photonic phase shifter (IMWPPS), consisting of mode-order converter multiplexers (MOCMs), a variable optical power splitter (VOPS), an optical switch (OS) and fixed time delay lines (FTDLs), was theoretically demonstrated in a silicon-on-insulator wafer. MOCMs, as a key element of our device, were employed to generate orthogonal vector signals and served as lossless optical combiners. Combining with the thermo-optical VOPS, OS and FTDLs, the microwave phase shift of 0∼2π could be achieved by a refractive index variation of 0∼15×10(-3) in the millimeter wave band. The corresponding tuning resolution was about 1.64°/°C. This work, for the first time to our knowledge, provides an attractive solution to transferring a vector-sum method based bulk MWPPS into a integrated one, which is very important for large-scale optically controlled phase array antenna.

Analysis and design of tunable wideband microwave photonics phase shifter based on Fabry-Perot cavity and Bragg mirrors in silicon-on-insulator waveguide.

We designed a microwave (MW) photonics phase shifter, consisting of a Fabry-Perot filter, a phase modulation region (PMR), and distributed Bragg reflectors, in a silicon-on-insulator rib waveguide. The thermo-optics effect was employed to tune the PMR. It was theoretically demonstrated that the linear MW phase shift of 0-2pi could be achieved by a refractive index variation of 0-9.68x10(-3) in an ultrawideband (about 38?GHz-1.9?THz), and the corresponding tuning resolution was about 6.92 degrees / degrees C. The device had a very compact size. It could be easily integrated in silicon optoelectronic chips and expected to be widely used in the high-frequency MW photonics field.

Analysis and design of thermo-optical variable optical attenuator using three-waveguide directional couplers based on SOI.

A thermo-optical variable optical attenuator (VOA), consisting of three cascaded three-waveguide directional couplers, was designed on Silicon-On-Insulator (SOI) wafer. Thermo-optical dynamic, static analysis and optical propagation characteristic simulation at the wavelength of 1550 nm were presented. The dynamic attenuation range from 0.14 dB to 50 dB was achieved by a refractive index (RI) variation: 0 to 5.55 x 10(-3), (the corresponding temperature variation: 0 to 30 degrees C). The response time was about 5 micros, which was attributed to Si/Al(2)O(3)/Si structure. The device could be easily used to fabricate multi-channel VOA as the basic unit and integrated in silicon optoelectronic circuits.

Collagen IX gene polymorphisms and lumbar disc degeneration: a systematic review and meta-analysis.

BACKGROUND: An increasing number of studies have investigated associations between collagen IX alpha 2 chain (COL9A2) and collagen IX alpha 3 chain (COL9A3) gene polymorphisms and the risk of lumbar disc degeneration (LDD). However, these studies have yielded contradictory results. The purpose of this meta-analysis is to investigate the association between the collagen IX gene polymorphisms (rs12077871, rs12722877, rs7533552 in COL9A2; rs61734651 in COL9A3) and LDD. METHODS: All relevant articles were collected from PubMed, Web of Science, and China National Knowledge Infrastructure (CNKI). The last electronic search was performed on September 1, 2017. The allele/genotype frequencies were extracted from each study. The odds ratio (OR) and 95% confidence interval (CI) were used to assess the strength of associations under the five comparison genetic models. Statistical analysis was performed by Review Manager (RevMan) 5.31 software. RESULTS: The meta-analysis of 10 case-control studies, including 2102 LDD cases and 2507 controls, indicated that COL9A2 gene (rs12077871, rs12722877, rs7533552) and COL9A3 gene (rs61734651) polymorphisms were not associated with LDD (rs12077871: T vs. C, OR = 1.85, 95% CI = 0.87-3.91, P = 0.11; rs12722877: G vs. C, OR = 0.83, 95% CI = 0.69-1.01, P = 0.06; rs7533552: G vs. A, OR = 1.11, 95% CI = 0.98-1.25, P = 0.09; rs61734651: T vs. C, OR = 1.57, 95% CI = 0.51-4.84, P = 0.43). The Egger text and the Begg funnel plot did not show any evidence of publication bias. CONCLUSION: rs12077871, rs12722877, and rs7533552 variants in COL9A2 and rs61734651 variant in COL9A3 were not significantly associated with a predisposition to LDD. Large-scale and well-designed studies are needed to confirm this conclusion.

Upregulation of Wnt signaling under hypoxia promotes lung cancer progression.

The hypoxic tumor microenvironment induces epithelial-mesenchymal transition (EMT) in tumor cells and increases tumor cell malignancy. Previous studies indicated that malfunction of Wnt signaling is observed in some lung cancer patients. Athough crosstalk between hypoxia and Wnt signaling in tumor cells has recently been revealed, the detailed underlying mechanisms have not been well defined. In the present study, we demonstrated that hypoxia in lung adenocarcinoma cells can enhance Wnt signaling activity by stabilizing ß-catenin and altering its localization into the nucleus. Overexpression of HIF-2α increased ß-catenin expression, promoted cell mobility, and induced morphological changes to a greater degree than HIF-1α overexpression. Knockdown of HIF-2α decreased ß-catenin expression and inhibited hypoxia-induced cell mobility. Moreover, we identified that phosphorylational activation of AKT1 by hypoxia and HIF-2α was required for Wnt activation upon hypoxia treatment. Downregulation of HIF-2α and ß-catenin reduced colony formation when cells were exposed to long-term hypoxia treatment. Taken together, our data support that hypoxia activates PI3K/AKT as well as Wnt signaling in a HIF-2α-dependent manner, thus elevating the resistance of lung cancer cells to chronic hypoxia-induced stress.

Semitransparent polymer solar cells with 5% power conversion efficiency using photonic crystal reflector.

Efficient semitransparent polymer solar cells (ST-PSCs) have been fabricated with one-dimensional photonic crystals (1DPCs) as a high reflector. The 1DPCs are composed of several pairs of WO3 (65.8 nm)/LiF (95.5 nm). By optimizing the pairs of WO3/LiF, 1DPCs can reflect the light back into the ST-PSCs due to the photonic band gap, when the high reflectance range of 1DPCs is matched with absorption spectrum of the active layer. ST-PSCs with 8 pairs of 1DPC exhibit an attractive performance. The short-circuit current density (Jsc) and power conversion efficiency (PCE), respectively, reach to 9.76 mA/cm(2) and 5.16% compared to 8.12 mA/cm(2) and 4.24% of the reference ST-PSCs without 1DPCs. A maximum enhancement of 20.2% in Jsc is obtained and the PCE increases by ~21.7%. This approach provides a simple, fascinating and promising method to realize the highly efficient ST-PSCs toward applications.