The pore size of porous scaffold plays a critical role in bone regeneration, but its mechanism and optimal value remain unclear. This study investigated the effect of pore size on hydromechanical ...properties of porous scaffold and its correlation with cellular response and bone regeneration. Porous titanium scaffolds with similar porosity and different pore sizes (400, 650, 850, and 1100 μm) were fabricated by selective laser melting. Their hydromechanical properties were derived by computational fluid dynamics analysis. The MC3T3 cells were dynamic seeded and cultured on the scaffolds to evaluate the cellular response. The rabbit distal femoral condyle implantation models were used to assess the bone ingrowth. Results indicated that the permeability, flow velocity, and the inflow of fluid linearly increased with the pore size. The wall shear stress evaluated from 400 to 650 μm and then dropped. These changes induced various performances in cell penetration, adhesion, proliferation, and differentiation, and finally induced best bone ingrowth in scaffold with pore size of 650 μm. This study provided a new understanding of the effect of pore size on bone regeneration of porous scaffold from the perspective of hydromechanics and indicated the potential of combining computational simulation and laboratory experiments in future studies.
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•Increasing the pore size linearly increased the permeability, flow velocity, and inflow of fluid.•The shear stress first increased and then decreased with the increase in pore size.•The pore size significantly affected the cell penetration, adhesion, proliferation, differentiation, and bone ingrowth.•The hydromechanical properties closely correlated with the cellular response and bone regeneration
The immune response plays a pivotal role in the pathogenesis of diseases. Toll-like receptor 4 (TLR4), as an intrinsic immune receptor, exhibits widespread in vivo expression and its dysregulation ...significantly contributes to the onset of various diseases, encompassing cardiovascular disorders, neoplastic conditions, and inflammatory ailments. This comprehensive review centers on elucidating the architectural and distributive characteristics of TLR4, its conventional signaling pathways, and its mode of action in diverse disease contexts. Ultimately, this review aims to propose novel avenues and therapeutic targets for clinical intervention.
•TLR4 has significant meaning in the occurrence and development of cardiovascular and cerebrovascular diseases.•TLR4 plays an important role in the occurrence and development of tumors through the immune system.•TLR4 has two signaling pathways: MyD88 dependent and MyD88 independent.
In order to prepare magnetorheological fluid with excellent sedimentation stability, various surfactants are applied to coat carbonyl iron powder. The prepared magnetorheological fluid shows ...excellent sedimentation stability when the surfactants are respectively sodium lauryl alcohol phosphate, compound sodium fatty acid methyl ester sulfonate, ethylene glycol monostearate and glyceride monostearate. Orthogonal tests are carried out for the optimal combination of surfactants and thixotropic agent. The experimental results show that the optimal combination of additives for MRF is 1.5 wt% of sodium lauryl alcohol phosphate, 1.0 wt% of compound MES, 1.5 wt% of ethylene glycol monostearate, 1.5 wt% of glycerol monostearate and 1.0 wt% of hydrophobic fumed silica. Magnetorheological fluid is prepared by the compound scheme, of which the viscosity is 1.09 Pa·s at 25.9°C and the sedimentation rate is 1.61% after one-week placement. The novel MRF is in excellent sedimentation stability and fluidity.
Intervertebral disc degeneration (IDD) is a complex multifactorial and irreversible pathological process. In IDD, multiple competing endogenous RNAs (ceRNA, including mRNA, lncRNA, and pseudogenes) ...can compete to bind with miRNAs. However, the potential metabolic signatures in nucleus pulposus (NP) cells remain poorly understood. This study investigated key metabolic genes and the ceRNA regulatory mechanisms in the pathogenesis of IDD based on microarray datasets.
We retrieved and downloaded four independent IDD microarray datasets from the Gene Expression Omnibus. Combining the predicted interactions from online databases (miRcode, miRDB, miRTarBase, and TargetScan), differentially expressed lncRNAs (DElncRNAs), miRNAs (DEmiRNAs), and mRNAs (DEmRNAs) were identified. A ceRNA network was constructed and annotated using GO and KEGG pathway enrichment analyses. Moreover, we searched the online metabolic gene set and used support vector machine (SVM) to find the critical metabolic DEmRNA(s) and other DERNAs. Differential gene expression was validated with a merged dataset.
A total of 45 DEmRNAs, 36 DElncRNAs, and only one DEmiRNA (miR-338-3p) were identified in the IDD microarray datasets. GO and KEGG pathway enrichment analyses revealed that the DEmRNAs were predominantly enriched in the PI3K-Akt signaling pathway, MAPK signaling pathway, IL-17 signaling pathway, apoptosis, and cellular response to oxidative stress. Based on SVM screening, 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (PFK/FBPase) 2 is the critical metabolic gene with lower expression in IDD, and AC063977.6 is the key lncRNA with lower expression in IDD. The ceRNA hypothesis suggests that AC063977.6, miR-338-3p (high expression), and PFKFB2 are dysregulated as an axis in IDD.
The results suggest that lncRNA AC063977.6 correlate with PFKFB2, the vital metabolic signature gene, via targeting miR-338-3p during IDD pathogenesis. The current study may shed light on unraveling the pathogenesis of IDD.
Selective laser melting (SLM) technique, based on a layer-by-layer production, was used to produce biomedical Co-Cr devices specifically developed for dental restoration applications. However, ...information on the metal-ceramic bond strength of SLM-manufactured parts was limited. In this study, SLM-fabricated Co-Cr alloy specimens were subjected to subsequent heat treatments (holding at 1150 °C for 1 h). The alloy microstructures were characterized by scanning electron microscopy (SEM) coupled with energy-dispersive x-ray spectroscopy (EDX), x-ray diffractometer (XRD), and transmission electron microscopy, whereas the bond properties were evaluated by 3-point bend tests and coefficient of thermal expansion (CTE) tests, as compared to casting (CAST) alloys. Results showed that SLM specimens exhibited fine grains and homogeneously dispersed intermetallic compounds, and the resultant XRD analysis revealed a predominated face-centered cubic γ-Co phase (72 %). Student's t-test demonstrated that bond strengths of SLM specimens (45.80 ± 1.91 MPa) were significantly lower than that of CAST specimens (54.05 ± 6.77 MPa) (P < 0.05), and SLM specimens with debonded surfaces analyzed via SEM/EDX analysis revealed a mixed fracture type of adhesive and cohesive fractures and lower area fractions of adherence porcelain. While porcelain firing, the microstructural evolution and thermal CTE matching seriously affected the metal-ceramic bond properties. SEM/EDX analysis of the metal-ceramic interface showed that reaction diffusion layers of CAST specimens were clearly thicker than that of SLM specimens, indicating that CAST specimens had a stronger chemical bonding force. Martensite transformation (γ →ε) occurred in the CAST metal matrix close to the interface, which was not found in the SLM specimens. Additionally, the dynamic thermal process revealed that CAST specimens exhibited superior CTE matching. Overall, Co-Cr alloy fabricated by SLM exhibited inferior metal-ceramic bond properties; however, it still meets the requirements for applications as dental prostheses (>25MPa specified in ISO9693).
Optical and visual measurement technology is used widely in fields that involve geometric measurements, and among such technology are laser and vision-based displacement measuring modules (LVDMMs). ...The displacement transformation coefficient (DTC) of an LVDMM changes with the coordinates in the camera image coordinate system during the displacement measuring process, and these changes affect the displacement measurement accuracy of LVDMMs in the full field of view (FFOV). To give LVDMMs higher accuracy in the FFOV and make them adaptable to widely varying measurement demands, a new calibration method is proposed to improve the displacement measurement accuracy of LVDMMs in the FFOV. First, an image coordinate system, a pixel measurement coordinate system, and a displacement measurement coordinate system are established on the laser receiving screen of the LVDMM. In addition, marker spots in the FFOV are selected, and the DTCs at the marker spots are obtained from calibration experiments. Also, a fitting method based on locally weighted scatterplot smoothing (LOWESS) is selected, and with this fitting method the distribution functions of the DTCs in the FFOV are obtained based on the DTCs at the marker spots. Finally, the calibrated distribution functions of the DTCs are applied to the LVDMM, and experiments conducted to verify the displacement measurement accuracies are reported. The results show that the FFOV measurement accuracies for horizontal and vertical displacements are better than ±15 µm and ±19 µm, respectively, and that for oblique displacement is better than ±24 µm. Compared with the traditional calibration method, the displacement measurement error in the FFOV is now 90% smaller. This research on an improved calibration method has certain significance for improving the measurement accuracy of LVDMMs in the FFOV, and it provides a new method and idea for other vision-based fields in which camera parameters must be calibrated.
Tranexamic acid (TXA) is well-established as a versatile oral, intramuscular, and intravenous (IV) antifibrinolytic agent. However, the efficacy of IV TXA in reducing perioperative blood transfusion ...in spinal surgery is poorly documented.
We conducted a meta-analysis of randomized controlled trials (RCTs) and quasi-randomized (qi-RCTs) trials that included patients for various spinal surgeries, such as adolescent scoliosis surgery administered with perioperative IV TXA according to Cochrane Collaboration guidelines using electronic PubMed, Cochrane Central Register of Controlled Trials, and Embase databases. Additional journal articles and conference proceedings were manually located by two independent researchers.
Totally, nine studies were included, with a total sample size of 581 patients. Mean blood loss was decreased in patients treated with perioperative IV TXA by 128.28 ml intraoperatively (ranging from 33.84 to 222.73 ml), 98.49 ml postoperatively (ranging from 83.22 to 113.77 ml), and 389.21 ml combined (ranging from 177.83 to 600.60 ml). The mean volume of transfused packed cells were reduced by 134.55 ml (ranging 51.64 to 217.46) (95% CI; P = 0.0001). Overall, the number of patients treated with TXA who required blood transfusions was lower by 35% than that of patients treated with the comparator and who required blood transfusions (RR 0.65; 95% CI; 0.53 to 0.85; P<0.0001, I(2) = 0%). A dose-independent beneficial effect of TXA was observed, and confirmed in subgroup and sensitivity analyses. A total of seven studies reported DVT data. The study containing only a single DVT case was not combined.
The blood loss was reduced in spinal surgery patients with perioperative IV TXA treatment. Also the percentage of spinal surgery patients who required blood transfusion was significantly decreased. Further evaluation is required to confirm our findings before TXA can be safely used in patients undergoing spine surgery.
Aims
To develop and validate a nomogram prediction model for the risk of diabetic foot in patients with type 2 diabetes mellitus (T2DM) and evaluate its clinical application value.
Methods
We ...retrospectively collected clinical data from 1,950 patients with T2DM from the Second Affiliated Hospital of Xi’an Jiaotong University between January 2012 and June 2021. The patients were divided into training cohort and validation cohort according to the random number table method at a ratio of 7:3. The independent risk factors for diabetic foot among patients with T2DM were identified by multivariate logistic regression analysis. Then, a nomogram prediction model was developed using the independent risk factors. The model performances were evaluated by the area under the receiver operating characteristic curve (AUC), calibration plot, Hosmer–Lemeshow test, and the decision curve analysis (DCA).
Results
Multivariate logistic regression analysis indicated that age, hemoglobin A1c (HbA1c), low-density lipoprotein (LDL), total cholesterol (TC), smoke, and drink were independent risk factors for diabetic foot among patients with T2DM (
P
< 0.05). The AUCs of training cohort and validation cohort were 0.806 (95% CI: 0.775∼0.837) and 0.857 (95% CI: 0.814∼0.899), respectively, suggesting good discrimination of the model. Calibration curves of training cohort and validation cohort showed a favorable consistency between the predicted probability and the actual probability. In addition, the
P
values of Hosmer–Lemeshow test for training cohort and validation cohort were 0.826 and 0.480, respectively, suggesting a high calibration of the model. When the threshold probability was set as 11.6% in the DCA curve, the clinical net benefits of training cohort and validation cohort were 58% and 65%, respectively, indicating good clinical usefulness of the model.
Conclusion
We developed and validated a user-friendly nomogram prediction model for the risk of diabetic foot in patients with T2DM. Nomograms may help clinicians early screen and identify patients at high risk of diabetic foot.
Objective
Spinal dural arteriovenous fistula (SDAVF) is a rare disease that is often misdiagnosed by orthopedic surgeons. We analyzed the reasons for the misdiagnosis and proposed countermeasures.
...Methods
Twenty-two SDAVF patients who were initially treated in orthopedics were included. The patients were divided into a correct diagnosis group (A) and a misdiagnosis group (B). The clinical data and prognosis were evaluated.
Results
There were 10 patients in group A and 12 patients in group B. The clinical manifestations included limb numbness, weakness, and bladder and bowel dysfunction. Among these patients without spinal degenerative diseases which had typical magnetic resonance imaging (MRI) features in Group A were more than Group B (
P
< 0.05). More patients had spinal degenerative diseases in group B. In group A, seven patients were primarily diagnosed with a SDAVF after multidisciplinary teamwork (MDT). In group B, five patients were misdiagnosed with lumbar spinal stenosis, four with lumbar disc herniation, two with thoracic spinal stenosis, and one with cervical spinal stenosis and lumbar spinal stenosis and underwent cervical spinal canal and lumbar spinal canal decompression. The length of time for confirming the diagnosis was 7 months longer in group B than in group A. All patients underwent microsurgery treatment. The average follow-up duration was 11 months. The modified Aminoff-Logue Disability Scale scores showed a statistically significant difference in improvement between the two groups (
P
< 0.05).
Conclusion
when patients with dysuria especially, have intermittent spinal nerve dysfunction, the possibility of SDAVF should be considered. Awareness of the specific clinical and spinal cord edema and flow voids on MRI of a SDAVF needs to be promoted for orthopedic surgeons. Timely MDT is an important measure for reducing misdiagnosis, and steroids or inappropriate surgery should be avoided until a SDAVF is completely excluded.
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