The Drosha-Independent MicroRNA6778-5p/GSK3ß Axis Mediates the Proliferation of Gastric Cancer Cells.

Background: Gastric cancer (GC) is a primary cause of cancer death around the world. Previous studies have found that Drosha plays a significant role in the development of tumor cells. Soon after, we unexpectedly found that the expression of microRNA6778-5p (miR6778-5p) is unconventionally high in the gastric cancer cells low-expressing Drosha. So, we designed the Drosha interference sequence and recombined it into a lentiviral vector to construct Drosha knockdown lentivirus and transfected the Drosha knockdown lentivirus into gastric cancer cells to establish Drosha knockdown gastric cancer cell lines. We aimed to explore the effect of microRNA6778-5p on the proliferation of gastric cancer cells with Drosha knockdown and its intrinsic mechanism. Methods: We designed the Drosha interference sequence and recombined it into a lentiviral vector to construct Drosha knockdown lentivirus and transfected the Drosha knockdown lentivirus into gastric cancer cells to establish Drosha knockdown gastric cancer cell lines. After transfecting miR6778-5p mimics and inhibitor into gastric cancer cell lines with Drosha knockdown, the expression levels of miR6778-5p mimics in Drosha low-expressing gastric cancer cells increased, while miR6778-5p inhibitor decreased the expression levels of miR6778-5p. The Cell Counting Kit-8 (CCK-8) experiment was used to detect the proliferation ability of gastric cancer cells after overexpression or knockdown of miR6778-5p and bioinformatics predicted the relationship between miR6778-5p and glycogen synthase kinase-3ß (GSK3ß). Results: After infection with the Drosha knockdown lentivirus, Drosha's mRNA and protein levels were significantly downregulated in gastric cancer cells. The expression levels of miR6778-5p mimics in Drosha low-expressing gastric cancer cells increased, while miR6778-5p inhibitor decreased the expression levels of miR6778-5p. Overexpression of miR6778-5p significantly enhanced the proliferation ability of Drosha low-expression gastric cancer cells; on the contrary, knocking down miR6778-5p weakened the proliferation ability of Drosha low-expression gastric cancer cells. Bioinformatics predicted that miR6778-5p targeted glycogen synthase kinase-3ß (GSK3ß) and the mRNA and protein levels of GSK3ß decreased significantly after overexpression of miR6778-5p. Conclusion: miR6778-5p promotes the proliferation of Drosha low-expressing gastric cancer cells by targeting GSK3ß.

Orofacial myofunctional changes in skeletal Class III patients after bimaxillary orthognathic surgery.

The aim of this study is to investigate the effect of bimaxillary orthognathic surgery on orofacial myofunctional changes in skeletal class III patients. 35 patients who received Le Fort I maxillary advancement osteotomy and mandibular SSRO setback were included in this study. Facial expression function was analyzed by "placid" or "smile" expressions using chL-chR, ∠chRnchL, and ls-li. Occlusal force and balance were analyzed using a T-scan III digital occlusal analysis system. Maximum mouth opening (MMO) was measured prior to surgery and 2/14/28/42/90/180/360 days after surgery. After surgery, patients recovered facial expressions in no less than 3 months for both the "placid" or "smile" facial expression. Patients obtained significantly improved 'smile' expressions 3 months after the operation compared to preoperative "smiles", and this improvement remained stable 12 months after the operation. Occlusal force was significantly decreased with the balance of occlusion lost immediately after surgery. These conditions gradually recovered, and patients finally obtained a more balanced and stronger occlusion [occlusion balance: 6.7 ± 2.7 mm vs. 4.1 ± 3.0 mm (day -7 vs. day 42); occlusion force: 19.6 ± 7.0 kg vs. 24.2 ± 9.3 kg (day -7 vs. day 180)]. However, patients had smaller postoperative mouth opening compared to preoperation opening during our follow-up. Our results confirmed that orthognathic surgery obstructs orofacial myofunctions of skeletal class III patients in the short-term. In the long-term, orthognathic surgery results in more stable and balanced orofacial myofunctions. By understanding the process of functional recovery of orofacial muscles after orthognathic surgery, we hope to accelerate patient's recovery from surgery.

Fabrication of SA/Gel/C scaffold with 3D bioprinting to generate micro-nano porosity structure for skin wound healing: a detailed animal in vivo study.

Bioprinting has exhibited remarkable promises for the fabrication of functional skin substitutes. However, there are some significant challenges for the treatment of full-thickness skin defects in clinical practice. It is necessary to determine bioinks with suitable mechanical properties and desirable biocompatibilities. Additionally, the key for printing skin is to design the skin structure optimally, enabling the function of the skin. In this study, the full-thickness skin scaffolds were prepared with a gradient pore structure constructing the dense layer, epidermis, and dermis by different ratios of bioinks. We hypothesized that the dense layer protects the wound surface and maintains a moist environment on the wound surface. By developing a suitable hydrogel bioink formulation (sodium alginate/gelatin/collagen), to simulate the physiological structure of the skin via 3D printing, the proportion of hydrogels was optimized corresponding to each layer. These results reveal that the scaffold has interconnected macroscopic channels, and sodium alginate/gelatin/collagen scaffolds accelerated wound healing, reduced skin wound contraction, and re-epithelialization in vivo. It is expected to provide a rapid and economical production method of skin scaffolds for future clinical applications.

Electrospun nanoyarn and exosomes of adipose-derived stem cells for urethral regeneration: Evaluations in vitro and in vivo.

Regeneration of urethral defects has been difficult in the clinic. To address it, the collagen/ poly (L-lactide-co-caprolactone) (P(LLA-CL)) nanoyarn scaffold delivering adipose-derived stem cells' exosomes (ADSC-exos) was fabricated. The multipotential differentiation potential of ADSCs were confirmed by Adipogenic, osteogenic, and chondrogenic differentiation. The 3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide assay shows that 50% concentration of ADSC-exos nanoyarn scaffold dramatically enhanced the cell viability of fibroblasts. The ADSC-exos nanoyarn scaffold for human foreskin fibroblasts (HFFs) and human urethral scar fibroblasts (HSFs) shows good biocompatibility: theproduction of inflammatory factors IL-6 and Col 1A1 was less, indicating that ADSC-exos had the minimal inflammatory effect of cells. Besides, the cells on the ADSC-exos nanoyarn scaffold did not appear to contribute to DNA damage in the same way as the normal cell's growth did. The HFFs seeding on the ADSC-exos nanoyarn scaffold shows a typical morphology of extending outwards. Urethral repair with ADSC-exos nanoyarn scaffold did not lead to either a sign of urethral stricture or scar formation after 4 weeks post-surgery. The deposition of collagen was less and the epithelial cells formed multiple layer epithelium. The treatment of ADSC-exos stimulated epithelization and vascularization. And the transition from an inflammatory state to a regenerative state was promoted. The ADSC-exos-treated group did not promote the over-proliferation of fibroblasts and the expression of Collagen I. Therefore, the ADSC-exos nanoyarn scaffold has evident, positive effects on wound healing and tissue fibrosis inhibition.

Fiducial-aided calibration of a displacement laser probing system for in-situ measurement of optical freeform surfaces on an ultra-precision fly-cutting machine.

Surface metrology is an essential operation to determine whether the quality of manufactured surfaces meets the design requirements. In order to improve the surface accuracy and machining efficiency in the manufacturing of optical freeform surfaces, in-situ surface measurement without re-positioning the workpiece is considered as a promising technique in advanced manufacturing. In this study, a displacement laser scanner is integrated into an ultra-precision fly-cutting machine in order to perform as a coordinate measuring machine. However, some inevitable errors such as motion errors of the machine tool, thermal drift, vibrations, and errors of the laser sensor are introduced due to the manufacturing environment. To improve the performance of the measurement system, calibration of the main error sources is investigated with consideration of the characteristics of the built laser scanner system. Hence, the relationship between the moving speed of the laser scanner and the vibration of the tested signals is studied. Following that, the errors of the z-axis scale could be corrected by measuring a four-step heights artefact. Furthermore, volumetric positioning errors are identified by the proposed modified chi-square method and Gaussian processing prediction method. Simulation and measurement experiments are conducted, and the results indicate that the calibrated measuring system can measure ultra-precision freeform surfaces with micrometre form accuracy.

Non-Lambertian Photometric Stereo Network based on Inverse Reflectance Model with Collocated Light.

Current non-Lambertian photometric stereo methods generally require a large number of images to ensure accurate surface normal estimation. To achieve accurate surface normal recovery under a sparse set of lights, this paper proposes a non-Lambertian photometric stereo network based on a derived inverse reflectance model with collocated light. The model is deduced using monotonicity of isotropic reflectance and the univariate property of collocated light to decouple the surface normal from the reflectance function. Thus, the surface normal can be estimated by three steps, i.e., model fitting, shadow rejection, and normal estimation. We leverage a supervised deep learning technique to enhance the shadow rejection ability and the flexibility of the inverse reflectance model. Shadows are handled through max-pooling. Information from a neighborhood image patch is utilized to improve the flexibility to various reflectances. Experiments using both synthetic and real images demonstrate that the proposed method achieves state-of-the-art accuracy in surface normal estimation.

Generation and characterization of ultra-precision compound freeform surfaces.

Compound freeform surfaces are widely used in bionic and optical applications. The manufacturing and measurement of such surfaces are challenging due to the complex geometry with multi-scale features in a high precision level with sub-micrometer form accuracy and nanometer surface finish. This article presents a study of ultra-precision machining and characterization of compound freeform surfaces. A hybrid machining process by combining slow slide servo and fast tool servo is proposed to machine compound freeform surfaces. The machining process for this hybrid tool servo is explained, and tool path generation is presented. Then, a normal template-based matching and characterization method is proposed to evaluate such compound freeform surfaces. Experimental studies are undertaken to machine a compound freeform surface using the proposed method based on a four-axis ultra-precision machine tool. The machined compound freeform surface is also measured and characterized by the proposed analysis and characterization method. The experimental results are presented, and the machining errors for compound freeform surfaces are also discussed.

A Study of Mechanics in Brittle⁻Ductile Cutting Mode Transition.

This paper presents an investigation of the mechanism of the brittle⁻ductile cutting mode transition from the perspective of the mechanics. A mechanistic model is proposed to analyze the relationship between undeformed chip thickness, deformation, and stress levels in the elastic stage of the periodic chip formation process, regarding whether brittle or ductile mode deformation is to follow the elastic stage. It is revealed that, the distance of tool advancement required to induce the same level of compressive stress decreases with undeformed chip thickness, and thereby the tensile stress below and behind the tool decreases with undeformed chip thickness. As a result, the tensile stress becomes lower than the critical tensile stress for brittle fracture when the undeformed chip thickness becomes sufficiently small, enabling the brittle⁻ductile cutting mode transition. The finite element method is employed to verify the analysis of the mechanics on a typical brittle material 6H silicon carbide, and confirmed that the distance of the tool advancement required to induce the same level of compressive stress becomes smaller when the undeformed chip thickness decreases, and consequently smaller tensile stress is induced below and behind the tool. The critical undeformed chip thicknesses for brittle⁻ductile cutting mode transition are estimated according to the proposed mechanics, and are verified by plunge cutting experiments in a few crystal directions. This study should contribute to better understanding of the mechanism of brittle⁻ductile cutting mode transition and the ultra-precision machining of brittle materials.

Fiducial-Aided Robust Positioning of Optical Freeform Surfaces.

Form characterization of a machined optical freeform surface demands accurate alignment of the sampled measured data points on the machined surface, and they are compared with the designed geometry of the surface through positioning. In this paper, a fiducial-aided robust positioning method (FAPM) is developed which attempts to evaluate freeform surfaces with high efficiency and precision. The FAPM method makes use of fiducials as reference datum to form a fiducial-aided computer-aided design (FA-CAD) of the freeform surface which not only establishes an inherent surface feature, but also links the different coordinate systems among design coordinate frame, machine tool, and measurement instrument. To verify the capability of the proposed method, a series of experiments were conducted. Compared with the traditional freeform measurement method (e.g., least squares method), the results indicate that the robustness and accuracy of the measurement is significantly enhanced by the FAPM.

Fiducial-aided on-machine positioning method for precision manufacturing of optical freeform surfaces.

There are still significant challenges in the accurate positioning of optical freeform surfaces on the machine tool and the measurement instrument due to the high accuracy requirement and their complex shapes. This paper proposes a Fiducial-aided On-machine Positioning method (FAOPM) that combines on-machine measurement and off-machine measurement to precisely position optical freeform surfaces during the precision manufacturing cycle including rough machining, fine machining, measurement, and error compensation. The FAOPM makes use of fiducials which are firstly measured on a coordinate measuring machine with nanometric accuracy to generate a Fiducial-aided Computer Aided Design (FA-CAD) of the designed optical surface, then the developed on-machine measuring device obtains the accurate positions of the fiducials after remounting in the machining coordinate system. Finally the relative position of the workpiece is identified so that the associated cutting paths and compensation tool path can be easily generated. Several optical freeform surfaces were experimentally machined to prove the capability of the proposed method. The results indicate that the positions of the workpiece during the precision manufacturing and measurement cycle were precisely achieved and the form accuracy of the optical freeform surfaces was remarkable improved based on the FAOPM.

Disparity pattern-based autostereoscopic 3D metrology system for in situ measurement of microstructured surfaces.

This paper presents a disparity pattern-based autostereoscopic (DPA) 3D metrology system that makes use of a microlens array to capture raw 3D information of the measured surface in a single snapshot through a CCD camera. Hence, a 3D digital model of the target surface with the measuring data is generated through a system-associated direct extraction of disparity information (DEDI) method. The DEDI method is highly efficient for performing the direct 3D mapping of the target surface based on tomography-like operation upon every depth plane with the defocused information excluded. Precise measurement results are provided through an error-elimination process based on statistical analysis. Experimental results show that the proposed DPA 3D metrology system is capable of measuring 3D microstructured surfaces with submicrometer measuring repeatability for high precision and in situ measurement of microstructured surfaces.

Estimation of measurement uncertainty caused by surface gradient for a white light interferometer.

Although the scanning white light interferometer can provide measurement results with subnanometer resolution, the measurement accuracy is far from perfect. The surface roughness and surface gradient have significant influence on the measurement uncertainty since the corresponding height differences within a single CCD pixel cannot be resolved. This paper presents an uncertainty estimation method for estimating the measurement uncertainty due to the surface gradient of the workpiece. The method is developed based on the mathematical expression of an uncertainty estimation model which is derived and verified through a series of experiments. The results show that there is a notable similarity between the predicted uncertainty from the uncertainty estimation model and the experimental measurement uncertainty, which demonstrates the effectiveness of the method. With the establishment of the proposed uncertainty estimation method, the uncertainty associated with the measurement result can be determined conveniently.

Autostereoscopy-based three-dimensional on-machine measuring system for micro-structured surfaces.

Traditional off-line measuring systems find it difficult to measure micro-structured workpieces which have a large volume and heavy weight, such as micro-structured patterned precision roller drums. This paper proposes an autostereoscopy-based three-dimensional (3D) measuring method and develops an innovative measuring system for the 3D on-machine measurement of the micro-structured surfaces, an Autostereoscopy-based Three-Dimensional On-machine Measuring (ATDOM) system. The ATDOM system is compact and capable of fast data acquisition and high accuracy in 3D computational reconstruction of complex surfaces under different measuring environments. A prototype ATDOM system is experimentally verified through a series of measurement experiments conducted on a precision machine tool. The results indicate that the ATDOM system provides an important means for efficient and reliable on-machine measurement of micro-structured surfaces.