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Transformers play a crucial role in power systems. In this respect, fault diagnosis and aging state assessment have garnered significant attention from researchers. Herein, accelerated thermal aging and Raman scattering experiments are conducted on oil–paper insulation samples to accurately detect aging states. The samples are categorized into different aging stages based on the polymerization degree of the insulating paper. Principal component analysis (PCA), multi-dimensional scale change method (MDS), and isometric mapping algorithm (Isomap) are employed to extract features from the Raman spectra. Subsequently, the XGBoost strong classifier, optimized through Bayesian hyperparameter optimization (BO-XGBoost), is utilized to distinguish between four and ten states among 175 groups of samples after feature extraction. The subsequent classification results of the three feature-extraction methods are compared. The results indicate that Isoamp, which pertains to the manifold dimension transformation, achieves the highest average discriminative accuracy after feature extraction. The discriminative accuracies for aging states four and ten are 97.0% and 95.1% respectively, demonstrating that Raman spectroscopy manifold dimension transformation enhances the distinctiveness between samples of different aging states in the feature-extraction process. The diagnostic model constructed with Isomap and BO-XGBoost enables accurate discrimination of the aging states of oil–paper insulation.

The voltage endurance coefficient n of cross-linked polyethylene (XLPE) insulation is an important indicator for the analysis of insulation failure mechanism. Accurately obtaining the value of n can provide technical support for the reliability evaluation of cable operation. The constant stress method and the step stress method are used to obtain the values of n, but the test parameters can influence the accuracy of the obtained n values. Two methods for selecting test parameters are proposed. The equivalence between the two methods is established, providing theoretical support for the accurate evaluation of the n value of solid insulation materials by using the step stress method. The accuracy of the evaluation results is verified by analyzing the test data. The test results show that the n=13.04 evaluated by the step stress test with the proposed parameter selection method is consistent with the test result of constant stress n=12.83.

Microwave dielectric CaTiO3 thin films were deposited on Pt/Ti/SiO2 coated Si substrates by a Pechini method. Crystal structures and morphologies of the CaTiO3 films were characterized by XRD and SEM, which confirms the pure perovskite phase, uniform thickness and smooth surface of the as-obtained thin films. Intrinsic mechanical characteristics of the CaTiO3 films were tested by nanoindentation method and were found to be strongly thickness dependent. The film modulus was found to decrease from 200 GPa (65 nm) to 189 GPa (250 nm) and then increase to 228 GPa (340 nm). The hardness improved monotonically from 15.6 (65 nm) to 21.7 GPa (340 nm). Our study suggests that the mechanical properties can be effectively tuned by film thickness and hence grain size control and may promote the design of high performance microwave dielectric devices for future applications.

The structural advantages of metal-organic frameworks (MOFs) can facilitate wide applications in the field of catalysis, including oxidation, hydrogenation, acetalization, transesterification, catalytic cracking, and so on. The efficiency of catalysis is closely related to the synergy between active center, auxiliary center, and microenvironment. Researchers can customize MOFs according to the needs of catalytic reactions, and many strategies were established for boosting catalytic performance. In this review, we aim to summarize and illustrate recent progress in the nanospace engineering of MOFs. Generally, MOFs were engineered mainly from the following aspects: 1) Regulation of pore size, including micropores, mesopores, and macropores. 2) Engineering of encapsulated active species, such as metal nanoparticles, quantum dots, polyoxometalates, enzymes, etc. 3) Engineering of MOFs morphology from zero dimension to three-dimension. 4) Controllable integration of MOFs with multi-strategies. 5) Construction of multivariate MOFs via introducing multiple or mixed organic functional groups into the existing framework. Besides, for further low cost and practical applications, challenges for MOFs as green and sustainable catalysts are also discussed.

Background. Gastric cancer (GC) is a malignant tumour that originates in the gastric mucosal epithelium and is associated with high mortality rates worldwide. Long noncoding RNAs (lncRNAs) have been identified to play an important role in the development of various tumours, including GC. Yet, lncRNA biomarkers in a competing endogenous RNA network (ceRNA network) that are used to predict survival prognosis remain lacking. The aim of this study was to construct a ceRNA network and identify the lncRNA signature as prognostic factors for survival prediction. Methods. The lncRNAs with overall survival significance were used to construct the ceRNA network. Function enrichment, protein-protein interaction, and cluster analysis were performed for dysregulated mRNAs. Multivariate Cox proportional hazards regression was performed to screen the potential prognostic lncRNAs. RT-qPCR was used to measure the relative expression levels of lncRNAs in cell lines. CCK8 assay was used to assess the proliferation of GC cells transfected with sh-lncRNAs. Results. Differentially expressed genes were identified including 585 lncRNAs, 144 miRNAs, and 2794 mRNAs. The ceRNA network was constructed using 35 DElncRNAs associated with overall survival of GC patients. Functional analysis revealed that these dysregulated mRNAs were enriched in cancer-related pathways, including TGF-beta, Rap 1, calcium, and the cGMP-PKG signalling pathway. A multivariate Cox regression analysis and cumulative risk score suggested that two of those lncRNAs (LINC01644 and LINC01697) had significant prognostic value. Furthermore, the results indicate that LINC01644 and LINC01697 were upregulated in GC cells. Knockdown of LINC01644 or LINC01697 suppressed the proliferation of GC cells. Conclusions. The authors identified 2-lncRNA signature in ceRNA regulatory network as prognostic biomarkers for the prediction of GC patient survival and revealed that silencing LINC01644 or LINC01697 inhibited the proliferation of GC cells.

Objective The aim of our study was to compare the value of computed tomography (CT) and 99mTc-methylenediphosphonate (MDP) SPECT (single photon emission computed tomography)/CT fusion imaging in determining the extent of mandibular invasion by malignant tumor of the oral cavity.

J Oral Pathol Med (2011) 40: 127–134 Objectives: The aim of this study was to define the biomarkers of lymphatic spread which facilitate the appropriate therapy for oral tongue squamous cell carcinoma (OTSCC) patients at early stage. Here, we investigated the expression levels of seven biomarkers in oral squamous cell carcinoma (OSCC) tissues as well as their associations with the clinicopathologic features of OTSCC patients. Methods: The OTSCC samples were obtained from 138 patients undergoing tumor resection. Immunohistochemical staining was performed by using ColIA, ColIVA, Fn1, MMP-1, MMP-2, uPA, and D2-40 antibodies. Expression level of theses biomarkers in normal and tumor tissues were compared. Risk factors of lymphatic dissemination were evaluated by logistic regression equation. Results: LVD, MMP-1, MMP-2, and uPA in cancer tissues were significantly higher than those in normal tissue, and ColIA, ColIVA, and Fn1 in cancer tissue were significantly lower than those in normal tissue. Similar results were obtained from the comparison between metastatic tumor and non-metastatic tumor. All biomarker expressions were closely related with lymph node status and clinical stage. Additionally, the regression equation demonstrated that LVD is the risk factor of lymphatic metastasis in OTSCC patients (OR = 1.732; 95% CIs: 1.167–2.057; P

To prospectively investigate the value of bone scintigraphy on determining the full extent of tumor involvement in jaw bones and to assess the presence of metastases. This study had local ethical committee approval, and all patients gave written informed consent. Thirty seven consecutive patients with primary malignant tumor in jaw bones were recruited for the study. Bone scintigraphy was performed in all patients before surgery to measure the full extent of bony involvement, which was compared with histologic findings. Whole body scan revealed one case with multiple bony metastases. Resection specimens of 36 bone neoplasms were pathologically analyzed to identify type and size of each tumor. The lengths of the tumor involvement in jaw bones defined by bone scintigraphy and pathology were 5.62 ± 1.58 cm, 4.48 ± 1.57 cm, respectively (P < 0.05). The tumor negative margins from removed specimens according to bone scintigraphy were pathologically confirmed. With histologic findings as the standard of reference, the accuracy of bone scintigraphy was 100% (36 of 36 patients) in determining the full extent of tumor involvement in jaw bones. Bone scintigraphy tends to offer specific guidelines in determining the appropriate extent of bone resection while entirely clearing the tumor cells and preserving functions whenever possible and in establishing the bony metastases.

The purpose of this study was to evaluate the efficacy of gallium-67 ((67)Ga) scanning in the differentiation of malignant tumors from benign tumors or inflammatory disease in the oral and maxillofacial region. Study design Fifty-two patients with tumors or inflammation in the oral and maxillofacial region underwent (67)Ga scanning. The results were compared with the final pathologic diagnosis.The gallium-67 scanning images for 20 of 21 patients who had malignant tumors were positive (95.23%); images for 3 out of 20 patients who had benign tumors also were positive (15%). There was a significant difference between malignant and benign tumors (P.001). Images for 2 of 11 patients with chronic inflammatory lesions were positive (18.2%), but, unlike the images of malignant tumors, the image outlines of the inflammatory lesions were indistinct and larger than the actual lesions.(67)Ga scanning is a useful adjunct tool for differentiation of malignant tumors from benign tumors or inflammatory disease in the oral and maxillofacial region.

Objective The aim of the study was to evaluate the clinical value of 99mTc-methylene diphosphonic acid (MDP) SPECT/CT fusion imaging and CT scanning in diagnosis of infiltrated mandible by gingival carcinoma.

To reconstruct mandibular defect using tissue engineering bone with bone marrow stem cells (BMSCs) cell sheets and investigate the effect of cell sheets on osteogenesis.BMSCs were isolated with the method of density gradient centrifugation from canine and cultured. BMSCs were induced to differentiate to osteoblasts. BMSCs induced were fabricated to BMSCs cell sheets. The poly (lactic-co-glycolic acid) (PLGA) wrapped with cell sheets were implanted into the mandibular defect in the left side (experimental side). PLGA wrapped without cell sheets were implanted into the right side (control side) of mandibles. 16 dogs were evenly divided into 4 groups, and one group of them was executed in 4, 8, 12, 16 weeks for gross investigation and histological observation.The osteogenesis of experimental side was better than that of control side. 16 weeks after implantation, most areas of the mandibular defect were replaced by fresh bone tissue. Compact bone similar to normal bone tissue formed in the lingual defect of mandible and had bony union with the bone stump. The optical density of the fresh bone in the experimental side was higher than that of the control side, there was a significant difference between the two methods (P0.05). Plenty of lamellar bones formed in experimental side and Haversian system, as well as red marrow, were observed.Tissue engineering bone with the structure of lamellar bones can be formed by the technology of BMSCs cell sheets.

To construct functional tissue-engineered bone with cell sheet technology and method of traditional bone tissue engineering.Canine bone marrow mesenchymal stem cells (BMSCs) were isolated with the method of density gradient centrifugation and cultured. BMSCs were induced to differentiate into osteoblasts and cultured in temperature-responsive culture dishes at 37 degrees C, 5% CO2 and saturated humidity. BMSCs cell sheet was prepared when temperature was changed to 20 degrees C. Demineralized bone matrix (DBM) and platelet-rich plasma (PRP) were prepared, and complex of DBM/PRP/BMSCs cell sheet/BMSCs was construsted and implanted under the left latissimus dorsi muscle. Complex of DBM/PRP/BMSCs was implanted under the right latissimus dorsi muscle.When temperature dropped at 20 degrees C, BMSCs detached automatically from the temperature-responsive culture dishes and formed an intact cell sheet. The osteogenesis of the DBM/PRP/BMSCs cell sheet/BMSCs group was better than that of the DBM/PRP/ BMSCs group.Cell sheet technology combined with traditional bone tissue provides a new way for construction of ideal functional tissue-engineered bone.

The aim of this study was to define the biomarkers of lymphatic spread which facilitate the appropriate therapy for oral tongue squamous cell carcinoma (OTSCC) patients at early stage. Here, we investigated the expression levels of seven biomarkers in oral squamous cell carcinoma (OSCC) tissues as well as their associations with the clinicopathologic features of OTSCC patients.The OTSCC samples were obtained from 138 patients undergoing tumor resection. Immunohistochemical staining was performed by using ColIA, ColIVA, Fn1, MMP-1, MMP-2, uPA, and D2-40 antibodies. Expression level of theses biomarkers in normal and tumor tissues were compared. Risk factors of lymphatic dissemination were evaluated by logistic regression equation.LVD, MMP-1, MMP-2, and uPA in cancer tissues were significantly higher than those in normal tissue, and ColIA, ColIVA, and Fn1 in cancer tissue were significantly lower than those in normal tissue. Similar results were obtained from the comparison between metastatic tumor and non-metastatic tumor. All biomarker expressions were closely related with lymph node status and clinical stage. Additionally, the regression equation demonstrated that LVD is the risk factor of lymphatic metastasis in OTSCC patients (OR = 1.732; 95% CIs: 1.167-2.057; P0.05).Down-regulation of ColIA, ColIVA, and Fn1 and up-regulation of LVD, MMP-1, MMP-2, and uPA might be important features of OSCC progression, which may exert their functions and favorably predict lymphatic dissemination for OSCC patients at relatively early stage. Among these biomarkers, increased LVD is an independent risk factor of lymphatic metastasis, which could better predict whether metastasis will occur or not.

Objective The purpose of the present study was to assess the head and neck imaging features of Madelung disease on computerized tomography (CT) and magnetic resonance imaging (MRI), delineate the effects of the fatty deposits on underlying structures, and tabulate the anatomic sites where the neck fat was deposited. Study design Sixteen Chinese patients with Madelung disease in our hospital were reviewed. The CT manifestations of the 16 cases and the MRI manifestations of 1 case were analyzed retrospectively. The imaging features of the fatty distribution in the head and neck area were studied. Results Cross-sectional CT showed that the excess fat was symmetric and unencapsulated, mainly deposited at the anterior or posterior subcutaneous tissue of the neck, was deep under the sternocleidomastoid and trapezius muscles, was situated in the posterior cervical triangle, and was around the salivary glands. It was also found to be situated in supraclavicular fossa, around the paraspinal muscles and larynx, and so on. The accumulated fat at superficial sites was situated at the napex and/or at the anterior neck, forming small or large fatty masses to protrude backwards locally or sometimes at submentum; the markedly thickened neck might appear tubby or oval in anteroposterior diameter.The accumulated fat at deep sites compressed adjacent muscles, salivary glands, and great vessels and caused them to shift and deform. The distinctive appearance was that marked thickening of fat caused sternocleidomastoid muscles and submaxillary glands to shift forward obviously, like a bird spreading its wings. The density of the abnormally proliferated fat was equal to that of normal fat. In MRI, the distribution of the excess fat was equal to that seen with CT. The signal intensity of the excess fat was equal to that of normal fat. Besides the accumulation of the neck fat tissue, CT and MRI did not show other abnormal soft tissue masses. Conclusions The use of CT and MRI can accurately show the excess fat based on density of CT and signal intensity of MRI. The density and signal intensity of the excess fat are equal to those of normal fat. The excess fat, mainly deposited at the anterior or posterior subcutaneous tissue of the neck, was deep under the sternocleidomastoid and trapezius muscles, was situated in the posterior cervical triangle, and was around the salivary gland, and so on. CT and MRI can also show compression, shift, and deformation of surrounding salivary glands, great vessels, and muscles caused by the excess fat. The CT and MRI can accurately diagnose the disease and exclude other soft tissue tumors.

To analyze the formant frequency of vowels in the sequence therapy of patient with cleft palate.The formant frequency of vowels [a], [e], [i], [u] of normal children and postoperative patients with and without speech therapy was measured and analyzed by VS-99.1. The mean value of F1, F2, F3 of [a] did not show significant difference among the three groups (P0.05). 2. The difference of mean value of [e] was significant between control group and pre-speech-therapy group, and between pre-speech-therapy and post-speech-therapy group (P0.05), but no significant difference was found between post-speech-therapy and control group(P0.05). The mean value of the formant in post-speech-therapy was higher than that of pre-speech-therapy. 3. The difference of mean value of [i] was significant between pre-speech-therapy and post-speech-therapy (P0.05), the mean value of F2, F3 in post-speech-therapy group decreased significantly compared with control (P0.05). 4. The difference of mean value of [u] showed significance between pre-speech-therapy and post-speech-therapy (P0.05), while the differences among other groups were insignificant (P0.05).Surgical repair of cleft palate cannot make all patients obtain perfect Velopharyngeal competence (VPC), while speech therapy can improve patient's pronunciation. Speech spectrum analysis can judge the effect of cleft palate therapy objectively.

The aim of this study was to rebuild the anatomic structures of the mandibular bone and the canal, and to testify the reliability of the rebuilt model.15 mandibular bones with teeth are chosen, and a three-dimensional model was built with the method of CT. The slices vertical to the compensating curve were made in every dental position. Then the authors collected the data of alveoli and mandibular canal in every slice. The same work was done to the bone specimen, and then comparative analysis was done.The wideness of the alveoli and 10 mm bellow increased from mesial to distal position. It was the same of the alveoli from the top to the bottom. The mandibular canal lied in the inner and inferior side of the mandibular body. There was no significant difference in data collected with these two methods.Different types of dental implants should be chosen according to the anatomic characteristic of the mandibular bone in every dental position before the operation to avoid complications. And a reliable, accurate and direct method of planning an implant operation is to rebuild a three-dimensional model.

To evaluate the effect of a system of velopharyngeal incompetence (VPI) management after the application of obturator.Using nasopharyngofiberoscope (NPF) and a computer analysis system, we quantitatively analyzed the improved state of velopharyngeal incompetence in 100 patients with unilateral and/or bilateral cleft palate.The velopharyngeal closure (VPC) can be greatly improved by using a temporary oral prosthesis (obturator) and speech training. An objective quantitative standard was established to evaluate the change of velopharyngeal closure of cleft palate patients after surgery and conservative treatment.The method used is more succinct, accurate and practical than previous methods. In order to reflect the state of velopharyngeal incompetence, the concept of improvement rate of velopharyngeal incompetence (IRVPI) is put forward.