Unilateral high-riding vertebral artery is associated with asymmetric morphological changes of the atlantoaxial joint: a novel risk factor for atlantoaxial osteoarthritis.

PURPOSE: This study aimed to investigate the association between unilateral high-riding vertebral artery (HRVA) and morphological changes in the atlantoaxial joint (AAJ) and to determine whether unilateral HRVA is a risk factor for atlantoaxial osteoarthritis (AAOA). METHODS: We conducted a retrospective analysis of 2496 patients admitted to our medical center between January 2020 and December 2022 who underwent CT imaging of the cervical spine. Two hundred and seventy-two patients with unilateral HRVA (HRVA group) were identified and a respective 2:1 age- and sex-matched control group without HRVA was built. Morphological parameters, including C2 lateral mass settlement (C2 LMS), C1/2 coronal inclination (C1/2 CI), lateral atlanto-dental interval (LADI), and C1/2 relative rotation angle (C1/2 RRA) were measured. The degree of AAOA was recorded. Risk factors associated with AAOA were identified using univariate and multivariable logistic regression analyses. RESULTS: The study included 61.4% women, and the overall average age of the study population was 48.7 years. The morphological parameters (C2 LMS, C1/2 CI, and LADI) in AAJ were asymmetric between the HRVA and the non-HRVA sides in the HRVA group (p < 0.001). These differences in parameters (d-C2 LMS, d-C1/2 CI, and d-LADI) between the HRVA and the non-HRVA sides, and C1/2 RRA were significantly larger than those in the control group. Eighty-three of 816 patients (10.2%) with AAOA had larger values of d-C2 LMS, d-C1/2 CI, d-LADI, and C1/2 RRA compared with the patients without AAOA (p < 0.05). The multivariable logistic regression analysis indicated that unilateral HRVA [adjusted odds ratio (OR) = 2.6, 95% CI: 1.1-6.3, p = 0.029], age in the sixth decade or older (adjusted OR = 30.2, 95% CI: 16.1-56.9, p < 0.001), women (adjusted OR = 2.1, 95% CI: 1.0-5.6, P = 0.034) were independent risk factors for AAOA. CONCLUSION: Unilateral HRVA was associated with asymmetric morphological changes of nonuniform settlement of C2 lateral mass, lateral slip of atlas, and atlantoaxial rotation displacement. Besides age ≥ 60 years and females, unilateral HRVA is an independent risk factor for AAOA.

Cellulose accumulation mediated by PbrCSLD5, a cellulose synthase-like protein, results in cessation of pollen tube growth in Pyrus bretschneideri.

Cellulose, a key component of the cell wall, plays an important role in maintaining the growth of pollen tubes. However, the molecular mechanism of cellulose participating in the cessation of pear pollen tube growth remains unclear. Here, we reported that at 15 h post-cultured (HPC), the slow-growth pear pollen tubes showed thickened cell walls and cellulose accumulation in the inner wall. Transcriptome data and quantitative real-time PCR analysis showed that PbrCSLD5, a cellulose synthesis-like gene, was highly expressed in the 15 HPC pear pollen tubes. Knockdown of PbrCSLD5 caused a decrease in cellulose content in pear pollen tubes. Moreover, PbrCSLD5 overexpression in Arabidopsis resulted in the accumulation of cellulose and disruption of normal pollen tube growth. Transcription factor PbrMADS52 was found to bind to the promoter of PbrCSLD5 and enhanced its expression. Our results suggested that the PbrMADS52-PbrCSLD5 signaling pathway led to increased cellulose content in the pear pollen tube cell wall, thereby inhibiting pollen tube growth. These results provided new insights into the regulation of pollen tube growth.

Enhanced Temperature Stability of High Energy Density Ferroelectric Polymer Blends: The Spatial Confinement Effect.

Thermal stability of polymer structure is a key to achieve stable energy density at elevated temperature for ferroelectric-polymer-based capacitors. Here, a poly (vinylidene fluoride) / polymethyl methacrylate (PMMA) blend with a stabilized spherulite structure displaying steady energy density around 7.8-9.8 J cm-3 across the temperature range up to 70 °C is reported, which outperforms most neat ferroelectric polymers at elevated temperature. The microstructure of the blend observed by atomic force microscopy exhibits an alternating lamellar structure (crystalline/mixed amorphous layers) within spherulites, which might be rationalized by PMMA being gradually expelled from the spherulite and finally staying between PVDF lamellae during crystallization. The structure with rigid amorphous layers can induce a spatial confinement effect of chain motion and structural change under thermal stress, which is evidenced by temperature-insensitive long period in small-angle X-ray scattering measurements. The enhanced thermal stability of energy storage can be attributed to the constraint on free volume and carrier transportation caused by the spatial confinement. Our findings provide a strategy to attain temperature-stable high-energy-density ferroelectric polymers for energy storage capacitors.

CuO/TiO2/MXene-Based Sensor and SMS-TENG Array Integrated Inspection Robots for Self-Powered Ethanol Detection and Alarm at Room Temperature.

In this study, a high-precision CuO/TiO2/MXene ethanol sensor operating at room temperature was prepared. The sensor exhibits excellent response value (95% @1 ppm ethanol), extremely low detection limit (0.3 ppm), fast response/recovery time (16/13 s), and remarkable long-term stability for trace detection of ethanol gas at room temperature, attributed to the p-n heterojunction formed by CuO and TiO2, as well as the rich functional groups and large specific surface area of MXene. Furthermore, a high-performance triboelectric nanogenerator (SMS-TENG) was developed through the introduction of the silicone/Mxene@silicone dual dielectric layer as the triboelectric layer, which improves the charge storage capacity of the dielectric layer and greatly enhances the output performance of the TENG. At the optimal doping ratio, the open-circuit voltage of the SMS-TENG can reach 1160 V, which is sufficient to light 720 LEDs. By combining the sensor and SMS-TENG, the resistive response of ethanol sensing is converted to a voltage response, which amplifies the response value up to 15.8 times. Finally, the designed SMS-TENGs are expected to be arrayed on an inspection robot as energy supply and combined with the CuO/TiO2/Mxene ethanol sensor to build a self-powered ethanol detection alarm system, endowing the inspection robot with the capability of self-powered ethanol detection at ppb level. This work provides an effective pathway for the intelligence of ethanol detection.

The association between unilateral high-riding vertebral artery and atlantoaxial joint morphology: a multi-slice spiral computed tomography study of 396 patients and a finite element analysis.

BACKGROUND CONTEXT: A high-riding vertebral artery (HRVA) can deviate too medially, too posteriorly, or too superiorly to allow the safe insertion of screws. However, it is unknown whether the presence of a HRVA is associated with morphological changes of the atlantoaxial joint. PURPOSE: To investigate the association between HRVA and atlantoaxial joint morphology in patients with and without HRVA. STUDY DESIGN: A retrospective case-control study and finite element (FE) analysis. PATIENT SAMPLE: A total of 396 patients with cervical spondylosis underwent multi-slice spiral computed tomography (MSCT) of cervical spine at our institutions from 2020 to 2022. OUTCOME MEASURES: A series of atlantoaxial joint morphological parameters, including C2 lateral mass settlement (C2 LMS), C1-2 sagittal joint inclination (C1-2 SI), C1-2 coronal joint inclination (C1-2 CI), atlanto-dental interval (ADI), lateral atlanto-dental interval (LADI), and C1-2 relative rotation angle (C1-2 RRA) were measured, and lateral atlantoaxial joints osteoarthritis (LAJs-OA) was recorded. The stress distribution on the C2 facet surface under different torques of flexion-extension, lateral bending, and axial rotation was analyzed by FE models. A 2-Nm moment was applied to all models to determine the range of motion (ROM). METHODS: A total of 132 consecutive cervical spondylosis patients with unilateral HRVA were enrolled in the HRVA group, and 264 patients without HRVA matched for age and sex were enrolled in the normal (NL) group. Atlantoaxial joint morphological parameters were compared between two sides of C2 lateral mass within HRVA or NL group, and between HRVA and NL groups. A 48-year-old woman with cervical spondylosis without HRVA was selected for cervical MSCT. A three-dimensional (3D) FE intact model of the normal upper cervical spine (C0-C2) was created. We established the HRVA model by simulating atlantoaxial morphological changes of unilateral HRVA with FE method. RESULTS: The C2 LMS was significantly smaller on the HRVA side than that on the non-HRVA side in the HRVA group, but C1-2 SI, C1-2 CI, and LADI on HRVA side were significantly larger than those on non-HRVA side. There was no significant difference between left and right sides in the NL group. The difference in C2 LMS (d-C2 LMS) between HRVA side and non-HRVA side in the HRVA group was larger than that in the NL group (P < 0.05). Meanwhile, the differences in C1-2 SI (d-C1/2 SI), C1-2 CI (d-C1/2 CI), and LADI (d-LADI) in the HRVA group were significantly larger than those in the NL group. The C1-2 RRA in the HRVA group was significantly larger than that in the NL group. Pearson correlations showed that d-C1/2 SI, d-C1/2 CI, and d-LADI were positively associated with d-C2 LMS (r=0.428, 0.649, 0.498, respectively, p<.05 for all). The incidence of LAJs-OA in the HRVA group (27.3%) was significantly larger than that in the NL group (11.7%). Compared with the normal model, the ROM of C1-2 segment declined in all postures of the HRVA FE model. We found a larger distribution of stress on the C2 lateral mass surface of the HRVA side under different moment conditions. CONCLUSIONS: We suggest that HRVA affects the integrity of the C2 lateral mass. This change in patients with unilateral HRVA is associated with the nonuniform settlement of the lateral mass and an increase in the lateral mass inclination, which may further affect the degeneration of the atlantoaxial joint because of the stress concentration on the C2 lateral mass surface.

A pipeline inspection robot for navigating tubular environments in the sub-centimeter scale.

In complex systems like aircraft engines and oil refinery machines, pipeline inspection is an essential task for ensuring safety. Here, we proposed a type of smart material-driven pipeline inspection robot (weight, 2.2 grams; length, 47 millimeters; diameter, <10 millimeters) that could fit into pipes with sub-centimeter diameters and different curvatures. We adopted high-power density, long-life dielectric elastomer actuators as artificial muscles and smart composite microstructure-based, high-efficiency anchoring units as transmissions. Fast assembling of components using magnets with an adjustable number of units was used to fit varying pipeline geometries. We analyzed the dynamic characteristics of the robots by considering soft material's unique properties like viscoelasticity and dynamic vibrations and tuned the activation voltage's frequency and phase accordingly. Powered by tethered cables from outside the pipe, our peristaltic pipeline robot achieved rapid motions horizontally and vertically (horizontal: 1.19 body lengths per second, vertical: 1.08 body lengths per second) in a subcentimeter-sized pipe (diameter, 9.8 millimeters). Besides, it was capable of moving in pipes with varying geometries (diameter-changing pipe, L-shaped pipe, S-shaped pipe, or spiral-shaped pipe), filled media (air or oil), and materials (glass, metal, or carbon fiber). To demonstrate its capability for pipeline inspection, we installed a miniature camera on its front and controlled the robot manually from outside. The robot successfully finished an inspection task at different speeds.

Management of fresh odontoid fractures using posterior C1-2 fixation without fusion: a long-term clinical follow-up study.

OBJECTIVE: Posterior C1-2 fixation without fusion makes it possible to restore atlantoaxial motion after removing the implant, and it has been used as an alternative technique for odontoid fractures; however, the long-term efficacy of this technique remains uncertain. The purpose of the present study was to explore the long-term follow-up outcomes of patients with odontoid fractures who underwent posterior C1-2 fixation without fusion. METHODS: A retrospective study was performed on 62 patients with type II/III fresh odontoid fractures who underwent posterior C1-2 fixation without fusion and were followed up for more than 5 years. The patients were divided into group A (23 patients with implant removal) and group B (39 patients without implant removal) based on whether they underwent a second surgery to remove the implant. The clinical outcomes were recorded and compared between the two groups. In group A, the range of motion (ROM) of C1-2 was calculated, and correlation analysis was performed to explore the factors that influence the ROM of C1-2. RESULTS: A solid fracture fusion was found in all patients. At the final follow-up, no significant difference was found in visual analog scale score or American Spinal Injury Association Impairment Scale score between the two groups (p > 0.05), but patients in group A had a lower Neck Disability Index score and milder neck stiffness than did patients in group B (p < 0.05). In group A, 87.0% (20/23) of the patients had atlantoodontoid joint osteoarthritis at the final follow-up. In group A, the C1-2 ROM in rotation was 6.1° ± 4.5° at the final follow-up, whereas the C1-2 ROM in flexion-extension was 1.8° ± 1.2°. A negative correlation was found between the C1-2 ROM in rotation and the severity of tissue injury in the atlantoaxial region (r = -0.403, p = 0.024) and the degeneration of the atlantoodontoid joint (r = -0.586, p = 0.001). CONCLUSIONS: Posterior C1-2 fixation without fusion can be used effectively for the management of fresh odontoid fractures. The removal of the implant can further improve the clinical efficacy, but satisfactory atlantoaxial motion cannot be maintained for a long time after implant removal. A surgeon should reconsider the contribution of posterior C1-2 fixation without fusion and secondary implant removal in preserving atlantoaxial mobility for patients with fresh odontoid fractures.

Morphometric Analysis of the Lateral Atlantoaxial Joints in Patients with an Old Type II Odontoid Fracture and Atlantoaxial Dislocation: A Study Based on CT Analysis.

MINI: The morphological features of the lateral atlantoaxial joints (LAJs) in patients with old type II odontoid fractures and atlantoaxial dislocation have not been fully analyzed. Our study found the changes in morphological features of the LAJs in some patients, and revealed the causes and consequences of the changes in morphological features of the LAJs.

Retrospective cohort study. We aimed to study and interpret the morphological features of the lateral atlantoaxial joints (LAJs) in patients with old type II odontoid fractures and atlantoaxial dislocation (AAD). The causes and consequences of the morphological changes of the LAJs in patients with old type II odontoid fractures and AAD have not been analyzed before. A retrospective study was performed on patients with old type II odontoid fracture and AAD. These patients were placed in group A (unstable or reducible dislocation) or group B (irreducible or bony dislocation) depending on the type of dislocation they had. We documented the morphological changes and measured the inclination angle of the articular surface of the LAJs in computerized tomographic images and compared the results collected for the two groups. The association between the history of injury and the inclination angle of the articular surface of the LAJs was assessed using the Pearson correlation coefficient. A total of 29 patients were enrolled (16 patients in group A, and 13 patients in group B). The inclination angle in group A was significantly greater than that in group B ( P  < 0.001). Patients in group B were more likely to have fish-lip-like changes, dome-like changes, or collapse of the LAJs. Age, history, atlantodental interval, and Japanese Orthopedic Association score were also significant differences between the two groups ( P  < 0.05). There was a negative correlation between the history of injury and the inclination angle of the articular surfaces of the LAJs (left: r = −0.726, P  < 0.001; right: r = −0.795, P  < 0.001). The morphological changes of the LAJs could progressively become more pronounced during the evolution of the disease. Level of Evidence: 4.

PCR-product microarray based on polyacrylic acid-modified surface for SNP genotyping.

PCR-product microarray has great efficiency in SNP genotyping, mutation screening and epigenetic analyzing from a large number of samples. The current PCR-product microarray technology is mostly based on the 3-D gel microarray technologies due to its high loading capacity for PCR products, while there is little progress for PCR-product microarray on planar glass, which gives low background and convenient fabrication. In this study, we improved the PCR-product microarray on planar glass by employing a polyacrylic acid-covered slide. The raw amino-modified PCR products were simply precipitated with ethanol and directly spotted for DNA immobilization. Three detection methods of hybridization, solid-single base extension and solid-multiple bases elongation were carried out for single nucleotide variation identification on the PCR-product microarray. The experimental results showed that the high immobilization yield for raw PCR product was achieved, and the high specificity and high ratio of S/N for genotyping on the microarray were obtained. SNP genotyping of cytochrome P450 2D6 gene in 30 individuals was successfully demonstrated. This study has significantly increased the performances of PCR-product microarray, which could improve its applications in SNP genotyping and mutation screening in large number of individuals.

Fiberoptic bronchoscopic view change of laryngopharyngeal tissues by different airway supporting techniques: comparison of patients with and without open mouth limitation.

STUDY OBJECTIVE: To investigate the changes in view of the laryngopharyngeal tissues on the fiberoptic bronchoscope (FOB) with different techniques of supporting the airway. DESIGN: Prospective, observational, stratified study. SETTING: University hospital. PATIENTS: 40 ASA physical status I, II, and III men undergoing elective oromaxillofacial surgery during general anesthesia with nasotracheal intubation. INTERVENTIONS: Patients were allocated into the normal mouth-opening group (Group N) or the limited mouth-opening group (Group L) to determine the grade of view of the laryngopharyngeal tissues exposed on the FOB, with 5 different airway supporting techniques: original airway position (OA), triple airway (TA), jaw thrust with opened mouth (JTO), jaw thrust with teeth protrusion (JTP), and head tilt with chin lift (HT). MEASUREMENT AND MAIN RESULTS: An adequate airway support was defined as having nearly full visibility of the entire glottic inlet. The investigator graded the vision of both anterior and posterior laryngopharyngeal tissues of each patient. All subjects experienced adequate airway support with the TA and HT airway supporting techniques. The TA airway supporting technique significantly moved the posterior laryngeal tissues more upward in Group N than Group L (P = 0.027). The JTP airway supporting technique provided adequate airway support for 14 of the 20 patients in Group N but only for two of the 20 Group L patients (P < .001). CONCLUSION: Both the TA and HT techniques provided adequate airway support for patients with and without limited mouth opening.

Phospholipase A2 inhibits nuclear nucleoside triphosphatase activity and mRNA export in isolated nuclei from rat liver.

The present study is undertaken to investigate whether the phospholipase A(2) (PLA(2)) influences mRNA nucleocytoplasmic transport evaluated by nucleoside triphosphatase (NTPase) activity and mRNA export in isolated hepatic nuclear envelope. Isolated hepatic nuclei from rat liver were exposed to PLA(2) (10(-5) approximately 10(-2)/ml) with or without incorporation of nuclei with phosphatidylcholine (PC) liposome. Messenger RNA exports and NTPase activities of nuclear membrane were assayed using ATP and GTP as substrates. We found that the RNA efflux, evaluated by [3H] uridine, was potently decreased in a concentration-dependent manner, by incubation of hepatic nuclei with PLA(2), regardless using ATP or GTP as substrates. The PC content in nuclear membrane was also decreased by PLA(2)-treatment. The PC was incorporated into the nuclear membrane by addition of phospholipid liposomes into the incubation mixture. PC incorporation into the nuclear membrane did not alter mRNA export. However this resulted in a significant increase in mRNA export rate in PLA(2)-treated group. Messenger RNA export rate in PLA(2) (10(-3) unit/mL)- treated nuclear membrane was positively correlated with level of PC incorporation, both using ATP and GTP as substrates. The activity of nucleoside triphosphatase, a nuclear membrane-associated enzyme, showed parallel variations with mRNA transport. It is concluded that nuclear PLA(2) plays a regulatory role in RNA transport, which can be antagonized by exogenous PC. These might be pathophysiologically significance, although the mechanisms by which this effect takes place remain to be clarified.

The train of four ratio decreases to zero in anesthetized children is the guide to achieve a satisfactory intubation condition.

The purpose of this study is to investigate the satisfactory (excellent or good) intubation conditions attained when the TOF ratio was zero in anesthetized children. Sixty children undergoing elective ophthalmic surgery were allocated randomly into three groups. Anesthesia was induced with thiopentone 4 mg/kg and halothane in combination with 66% N2O and O2 (2 L/min). Patients maintained spontaneous breathing with assisted ventilation to limit the values of end tidal CO2 within the range of 36-44 mmHg, maintained the stable end tidal expiratory 1 MAC halothane concentration for three minutes and followed by 0.1 mg/kg vecuronium in group 1, 0.6 mg/kg rocuronium in group 2, and 0.9 mg/kg rocuronium in group 3. Intubation was attempted as the TOF ratio decreased from 1.0 to 0. The intubation condition was scored by assessing the degree of jaw relaxation, vocal cord opening grades, and cough responses. The overall intubation conditions were graded as excellent, good, fair, and poor on the basis of the scores. Excellent or good intubation conditions were considered satisfactory. After neuromuscular blockade administration, TOF ratio required 160.5 +/- 28.9 seconds in group 1, 70.7 +/- 18.5 seconds in group 2, and 55.7 +/- 13.5 seconds in group 3 to decrease to zero. There is a significant difference between group 1 and group 2 and 3 (p < 0.001, group 1 vs group 2 and group 3). All children were intubated, during which procedures satisfactory intubation conditions were observed in all of the group 3 patients, in 17 of the 20 group 2, and in 16 of the 20 group 1 patients. We concluded that zero of TOF from monitoring the adductor pollicis muscle indicated the proper moment for intubation in anesthetized pediatric patients and it was a reliable guide in adequately anesthetized children to achieve satisfactory intubation conditions following 0.9 mg/kg rocuronium administration.

[The effect of liposome-carried metallothionein on secondary venous ischemia-reperfusion injury in a rat flap].

OBJECTIVE: To investigate the effect of liposome-carried metallothionein (lipo-MT) on secondary ischemia-reperfusion injury in the rat island flap. METHODS: An abdominal island flap was created in the Wistar rat. The animals were divided into four groups: the sham group, the secondary ischemia-reperfusion group, the group treated with blank liposome and the group treated with lipo-MT. The malondialdehyde (MDA) content, the myeloperoxidase (MPO) activity was assayed immediately, at 30 minutes and 7 days after the secondary venous ischemia-reperfusion. The level of endothelin (ET) and lactic dehydrogenase (LDH) of the rat plasma was measured at 30 minutes after secondary venous ischemia-reperfusion. The content of MT of the flap was assayed by Cd-hemoglobin saturation method at 7 days after the operation. RESULTS: The treatment of lipo-MT significantly decreased the content of MDA, MPO of the flap, decreased the activity of ET, LDH of the rat palsma, increased the content of MT of the flap and improved the flap viability. CONCLUSION: Lipo-MT can improve flap survival by reducing ischemia-reperfusion injury.