Search

Electrical capacitance tomography (ECT) is a potent image-based measurement technology for monitoring industrial processes, but low-quality images generally limit its application scope and measurement reliability. To increase the precision of reconstruction, in this study, a data-driven plug-and-play prior abstracted by a deep convolutional neural network (DCNN) and the sparseness prior of imaging objects, in form of regularizers, are jointly leveraged to generate a potent imaging model, in which the L1 norm of the mismatch error acts as a data fidelity term (DFT) to weaken the sensitivity of estimation result to noisy input data. The DCNN is embedded into the split Bregman (SB) technique to generate a powerful computing scheme for solving the built imaging model and the fast iterative shrinkage-thresholding algorithm (FISTA) is applied to solve the sub-problems efficiently. Extensive numerical results verify that the proposed imaging technique has competitive reconstruction ability and better robustness in comparison with the state-of-the-art methods. This study demonstrates the validity and efficacy of the proposed algorithm in reducing reconstruction error. Most importantly, the research outcomes verify that the data-driven plug-and-play prior and the sparseness prior can be jointly embedded into the imaging model, leading to a remarkable decline in reconstruction error. [ABSTRACT FROM AUTHOR]

Composite Co-based/Al2O3/rare earth (La2O3) mixture coatings were fabricated onto the surface of 4145H modified high tensile steel by CO2 laser cladding. Microhardness, microstructure and phase of the coating were analysed using a microhardness tester, an optical microscope, a scanning electron microscope (SEM) and X-ray diffraction (XRD). The wear and corrosion resistance of the composite coatings were investigated by a reciprocating friction wear tester and electrochemical workstation, respectively. The results indicate that the laser clad composite coating exhibited high average hardness of 627 HV0.2 and density by adding 5% Al2O3 and 0.4% rare earth (La2O3) to the Co-based alloy powder. The laser clad composite coating shows excellent wear resistance. The friction coefficient of the laser clad composite coating was 0.55, which is lower than the 4145H steel substrate at 0.7. The weight loss of the laser clad composite coating was only 1/3 that of the 4145H steel substrate. The corrosion resistance of the laser clad composite coating was also superior to that of the 4145H steel substrate. [ABSTRACT FROM AUTHOR]

Fe-Mn-Si/WC/Y2O3 composite coatings were prepared by laser cladding on the surface 304 stainless steel. The microstructure, phase composition, microhardness, and wear resistance as well as corrosion resistance of the composite coating were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), microhardness tester, friction wear tester and electrochemical workstation. The results show that WC is completely decomposed due to the high laser energy density and presents as in situ Fe6W6C phase and solid-solved in the coating. Microstructure of the coating consists of planar crystal, cell crystal, dendrites and equiaxed crystal. The wear resistance of the composite coating is simultaneously enhanced by solid solution strengthening, dispersion strengthening and the stress self-accommodation characteristic of Fe-Mn-Si shape memory alloy (SMA). The addition of Y2O3 makes the surface potential of the composite coating uniform, purifies the grain boundary and improves the corrosion resistance of the composite coating. When the content of Y2O3 is 0.8 wt. %, the wear resistance and corrosion resistance of the coating are optimal. [ABSTRACT FROM AUTHOR]

To obtain high performance coating materials a Fe5Cr5SiTiCoNbMoW high entropy alloy coating was prepared for deposition onto 6542# and Q235 tool steel by CO2 laser cladding. The microstructure, microhardness, corrosion resistance and wear resistance of the coatings were investigated. The experimental results showed that the Fe5Cr5SiTiCoNbMoW high entropy alloy is mainly composed of body-centred cubic (BCC) phase accompanied with a few metal carbides. The microstructure was dendritic crystal. The hardness and wear resistance of the Fe5Cr5SiTi-CoNbMoW high entropy alloy coated 6542# tool steel with high C content was higher than those of the Fe5Cr5SiTiCoNbMoW high entropy alloy coated Q235 tool steel. [ABSTRACT FROM AUTHOR]

A calcium phosphate bioceramic coating with β-Ca3(PO4)2 (β-TCP) and hydroxyapatite (HA) on a titanium alloy was prepared by means of the laser cladding technique using a CO2 laser. The surface morphology, microstructure and microhardness were analysed. The experimental results indicate that this kind of gradient coating is comprised of bioceramic coating, alloying layer and heat affected zone (HAZ) as well as the substrate. There is an excellent metallurgical bonding among layers. The phases of coating mainly contains CaTiO3, TiO2, β-TCP and HA. The bioactivity of calcium phosphate bioceramic coating is directly related to the amount of synthesizing HA and β-TCP. The rare earth oxide La2O3 can affect the formation of β-TCP and HA. Also, the rare earth oxide La2O3 has great influence on crack susceptibility of the coating. The surface of coating is smooth and the quality is improved by adding La2O3. The bioceramic coating was immersed in SBF to examine its bioactivity for two weeks. The surface of the bioceramic with La2O3 has formed a large amount of bone-like apatite. [ABSTRACT FROM AUTHOR]

Ice patterns can be used to make ceramic investment moulds for metal castings. Owing to the characteristics of ice, the ceramic mould must be made at subzero temperatures and consequently, requires a different formulation than shells built at room temperature. Success of this process depends greatly on the fracture toughness of mould materials. The present paper describes the experimental results of fracture toughness of mould materials processed from different compositions. The Taguchi method was used to reduce the trial runs. The parameters considered included the ratio of fibre containing fused silica and aluminosilicate powders, the volume of binder and the volume of catalyst. The microstructure and green fracture surface of test bars were also examined to understand the underlying mechanism. While conducting the four point bend test on ceramic mould samples, some samples had exceedingly low strengths appearing as outliers in the Weibull analysis. Examination of these low strength ceramic samples improved understanding of failure of mould materials. Sound moulds have been made for the investment casting process with ice patterns based on the analysis of experimental results. The casting of an M8 bolt is used to demonstrate that metal castings of complex geometry can be fabricated using ice patterns. The measured tolerances are within the required tolerance range. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the efficacy and safety of first-line anti-tuberculosis (TB) drugs combined with linezolid in treatment of children with tuberculous meningitis (TBM). Methods: A retrospective cohort study design was performed . Eight-nine Children diagnosed as TBM during January 1 st 2016 and December 31 st 2023 in Department of Infectious Disease, Children's Hospital of Chongqing Medical University were enrolled in the study. According to different treatment regimens, children were divided into a group of first-line anti-tuberculous drugs (isoniazid, rifampicin, pyrazinamide, ethambutol (HRZE)) and a group of HRZE and linezolid combination (HRZEL). The efficacy and safety of the 2 regimens were compared and the relationship between linezolid drug concentration and adverse reactions were analyzed. Comparisons between groups were performed using χ 2 test and Mann-Whitney U test. Results: The 89 children with TBM included 53 males and 36 females with an onset age of 4.6 (1.4, 9.6) years. There were 27 cases in the HZREL group and 62 cases in the HRZE group. Before treatment, positive rate of interferon-gamma release assays (IGRA) in HRZEL group was lower than that in HRZE group (64% (16/25) vs. 92% (55/60), χ 2 =9.82, P <0.05), but protein level of cerebrospinal fluid (CSF) was higher than that in HRZE group (1.2 (1.0, 2.0) vs. 0.8 (0.4,1.4) g/L, Z =0.32, P <0.05). By the end of the intensive phase, there were no significant differences of rates of CSF improvement and etiology negativity between HRZEL group and HRZE group (both P >0.05).The 44 TBM children with high CSF protein (>1 g/L) included 25 males and 19 females with an onset age of 6.7 (3.0, 11.8) years. There were 21 cases in the HZREL group and 23 cases in the HRZE group accordingly. Before treatment, there were no significant differences of positive rate of IGRA test and CSF protein level between the 2 groups (62% (13/21) vs. 87% (20/23), 1.7 (1.1, 2.2) vs. 1.5 (1.2, 1.9) g/L, χ 2 =3.67, Z =0.23, both P >0.05). There were no significant differences in CSF indicators, etiology negativity or imaging remission between the two groups by the end of intensive phase (all P >0.05). Higher frequencies of granulocytopenia, gastrointestinal symptoms as well as withdrawal or change of drugs were found in HRZEL group when compared to those in HRZE group (44% (12/27) vs. 19% (12/62), 7% (2/27) vs. 0, 33% (9/27) vs. 3% (2/62), χ 2 =6.01, 4.70, 15.74, all P <0.05). Conclusions: The efficacy of HRZEL regimen is similar to conventional HRZE regimen in children with TBM, but with higher adverse effect. Prudentially evaluating the pros and cons of linezolid in the usage of drug-susceptible TB and carefully monitoring of linezolid associated adverse effects is suggested.

Objective: To examine the efficacy of uniportal video-assisted thoracoscopic surgery in the treatment of tuberculous destroyed lung. Methods: This is a retrospective case series study. The clinical data of 33 patients with tuberculous destroyed lung who had received uniportal video-assisted thoracoscopic pulmonary resection from June 2020 to May 2022 in Department of Surgery, Wuhan Pulmonary Hospital were retrospectively analyzed. There were 13 males and 20 females, aged (47.5±16.2) years (range: 19 to 68 years). The course of the disease was from 15 days to 8 years. All 33 cases had pleural adhesions, including 30 cases with total pleural adhesions and atresia. There were 21 cases of calcification of the thoracic lymph node, 17 cases of aspergillus infection, 4 cases of drug-resistant tuberculosis. The surgical incision was located at the midline of the fifth intercostal axilla, length 4 to 5 cm. The principle of separating pleural adhesions was easy first and difficult later, and then appropriate procedures were selected to resect the diseased lung based on the exploration situation. There were 12 cases that underwent superior lobectomy, 11 cases that underwent superior lobectomy and dorsal segmentectomy, 3 cases that underwent inferior lobectomy, 3 cases that underwent pneumonectomy, 2 cases that underwent middle and inferior lobectomy, and 1 case that underwent superior lobectomy, dorsal segmentectomy and basal segment wedgectomy. The surgical techniques, perioperative evaluation and treatment, management of complications, and the outcome were summarized. Results: Six cases were converted to thoracoscope assisted small incision or thoracotomy. For 27 cases who successfully underwent uniportal VATS, the operation time was (238.7±76.8) minutes (range: 60 to 420 minutes), the intraoperative bleeding was (400.4±315.9) ml (range: 50 to 1 200 ml). The duration of postoperative drainage was (12.7±8.3) days (range: 3 to 42 days). The postoperative hospital stay was (15.2±7.9) days (range: 6 to 43 days). Persistent postoperative pulmonary leakage occurred in 12 cases. There were 2 cases of active thoracic bleeding, one of which was cured with conservative treatment. The other case underwent secondary operation. One case of bronchopleural fistula was cured after continuous thoracic drainage to control infection and implantation of one-way bronchial valve through a fiberoptic bronchoscope. Conclusion: For selected patients with tuberculous destroyed lung, choosing the reasonable surgical procedures and techniques, the uniportal VATS could reduce surgical trauma.

The patient had received five courses of anti-tuberculosis treatment for recurrent tuberculosis. The drug sensitivity test results of the first three courses showed drug-sensitive pulmonary tuberculosis, and the fourth diagnosis was rifampin-resistant tuberculosis (RR-TB), complicated by chronic obstructive pulmonary disease, type Ⅱ respiratory failure, pulmonary heart disease, and heart failure (grade Ⅲ). The patient stopped taking the anti-tuberculosis drugs on his own in the eighth month of receiving the resistant treatment. After admission, the symptoms improved temporarily after receiving oxygen therapy, anti-infection, and anti-tuberculosis treatment. Because of hemoptysis, the patient underwent arterial embolization by catheterization, but a large amount of hemoptysis occurred shortly thereafter. Emergency left total lung resection and gauze packing for hemostasis were performed. After surgery, the patient's vital signs were maintained with mechanical ventilation and vasopressors. Forty-eight hours after surgery, the gauze was removed, and the patient underwent tracheotomy, enteral nutrition, and anti-tuberculosis treatment. After discharge, the patient underwent rehabilitative exercise and anti-resistant tuberculosis therapy. The patient's condition remained stable for more than six months of follow-up.

Objective: To examine the safety and efficacy of the uniportal video-assisted thoracoscopic decortication in treatment of drug-resistant tuberculosis empyema. Methods: From January 2018 to December 2020, 122 cases of tuberculous empyema treated by decortication in Department of Surgery, Wuhan Pulmonary Hospital were retrospectively analyzed, including 100 males and 22 females, aged( M (IQR)) 29.5(28.0) years (range: 13 to 70 years). According to the surgical approach and drug resistance, patients with drug-resistant tuberculosis who underwent uniportal video-assisted thoracoscopic decortication were included in group A ( n =22), and those who underwent thoracotomy decortication were included in group B ( n =28). Drug-sensitive patients who underwent uniportal video-assisted thoracoscopic decortication were included in group C ( n =72). There was no statistical difference in the baseline data of the three groups ( P >0.05). The operation, early postoperative recovery, and prognosis-related indicators were compared among three groups by Kruskal-Wallis test and χ 2 test and Bonferroni method between groups A and B, groups A and C. U The intraoperative blood loss of group A, group B, and group C was 200(475) ml, 300(200) ml, and 225(300) ml, respectively. There was no significant difference in intraoperative hemorrhage ( Results: The intraoperative blood loss of group A, group B, and group C was 200(475) ml, 300(200) ml, and 225(300) ml, respectively. There was no significant difference in intraoperative hemorrhage ( H =2.74, P =0.254) and treatment outcome ( χ =0.575) among the three groups. Compared with group B, the operation time of group A (302.5(187.5) minutes 2 =4.76, P =0.575) among the three groups. Compared with group B, the operation time of group A (302.5(187.5) minutes vs. 200.0(60.0) minutes, U =171.0, P =0.007) and postoperative pulmonary reexpansion duration (4.5(3.0) months vs. 3.0 (2.2) months, U =146.5, P =0.032) were longer, and the postoperative drainage duration (9.5(7.8) days vs. 13.0(10.0) days, U =410.0, P =0.044), and the postoperative hospitalization time (12.0(7.8) days vs. =0.020) were shorter. There was no significant difference in complications between group A and group B (63.6%(14/22) U =462.2, P =0.020) were shorter. There was no significant difference in complications between group A and group B (63.6%(14/22) vs. 71.4%(20/28), χ 2 =0.34, P =0.558). Compared with group C, the postoperative drainage duration of group A (9.5(7.8) days vs. 7.0(4.0) days, U =543.5, P =0.031), the postoperative hospitalization time (12.0(7.8) days vs. 9.0(4.0) days, U =533.0, P =0.031) and postoperative pulmonary reexpansion duration (4.5(3.0) months vs. 3.0(2.0) months, U =961.5, P =0.001) were longer. The operation time (302.5(187.5) minutes vs. 242.5(188.8) minutes, U =670.5, P =0.278), and complications (63.6%(14/22) vs. 40.3%(29/72), χ 2 =3.70, P =0.054) were not different between group A and group C. Conclusions: For drug-resistant tuberculous empyema, the uniportal video-assisted thoracoscopic decortication can achieve the same good therapeutic effect as drug-sensitive tuberculous empyema, and it is as safe as thoracotomy. At the same time, it has the advantage of minimally invasive and can accelerate the early postoperative recovery of patients.

Objective: To study the different expression of 4 microRNA (miRNA, miR) during the osteogenesis differentiation of bone marrow mesenchymal stem cell (BMSC) cultured in high-fat or normal environment and to explore the relationship of these miRNAs with disheveled 2 during osteogenesis differentiation. Methods: BMSC were cultured with 2 ml normal osteogenic induction (control group) and high-fat osteogenic induction (high-fat group) respectively. On the 3rd, 5th, 7th,14th, 21st day, quantitative real-time PCR (qPCR) was used to analyze expression levels of four miRNAs (miR-21-5p, miR-29c-3p, miR-138-5p and miR-351-5p), mRNA of disheveled 2, osteogenic related factors such as alkaline phosphatase (ALP), Runt-related transcription gene 2 (Runx2). And the protein was detected by Western blotting. After BMSC were transfected by 50 μl 50 nmol/L miRNA mimics/inhibitors/negative controls respectively, BMSC were put on osteogenic induction, on the 1st, 3rd, 5th, 7th day, ALP activity was detected. On the 7th day, ALP staining was to observe the degree of osteogenesis differentiation, and Western blotting was adopted to analyze the expression of dishevelled 2 and other osteogenic related factors, while qPCR was used to analyze the expression of disheveled 2 mRNA. After 293T cells were co-transfected with disheveled 2 wild-type/mutant firefly luciferase reporter plasmid with either negative control (NC) or a mimic of these four miRNAs respectively for 48 h, luciferase activities were measured. Results: On the 21th day, the expressions of miR-21-5p, miR-29c-3p, miR-138-5p and miR-351-5p in high-fat groups were higher by 20%, 60%, 340% and 4 420% respectively than those in control groups ( P< 0.05). The expression of ALP and Runx2 in BMSC decreased after BMSC transfected miR-21-5p and miR-29c-3p mimics, while increased after transfected miR-21-5p and miR-29c-3p inhibitors. The expression of disheveled 2 decreased by 35% after transfected by miR-29c-3p mimic, while it increased by 269% after transfected by miR-29c-3p inhibitor ( P< 0.05). Transfection of the miR-29c-3p mimics significantly decreased the luciferase activity of wild-type 3 ' -UTR compared with NC control ( P< 0.05). There were no statistical significances among other groups. Conclusions: miRNAs had better expression during osteogenesis differentiation of BMSC in high-fat environment; miR-29c-3p could negatively regulate the osteogenesis differentiation of BMSC by targets on dishevelled 2.

The extraction of crystallography information from electron backscatter diffraction (EBSD) patterns can be facilitated by diffraction simulations based on the dynamical electron diffraction theory. In this work, the EBSD patterns are successfully simulated by two multislice methods, that is, the real space (RS) method and the revised real space (RRS) method. The calculation results by the two multislice methods are compared and analyzed in detail with respect to different accelerating voltages, Debye-Waller factors and aperture radii. It is found that the RRS method provides a larger view field of the EBSD patterns than that by the RS method under the same calculation conditions. Moreover, the Kikuchi bands of the EBSD patterns obtained by the RRS method have a better match with the experimental patterns than those by the RS method. Especially, the lattice parameters obtained by the RRS method are more accurate than those by the RS method. These results demonstrate that the RRS method is more accurate for simulating the EBSD patterns than the RS method within the accepted computation time., (© 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society.)

In the transmission electron microscopy, a revised real space (RRS) method has been confirmed to be a more accurate dynamical electron diffraction simulation method for low-energy electron diffraction than the conventional multislice method (CMS). However, the RRS method can be only used to calculate the dynamical electron diffraction of orthogonal crystal system. In this work, the expression of the RRS method for non-orthogonal crystal system is derived. By taking Na2 Ti3 O7 and Si as examples, the correctness of the derived RRS formula for non-orthogonal crystal system is confirmed by testing the coincidence of numerical results of both sides of Schrödinger equation; moreover, the difference between the RRS method and the CMS for non-orthogonal crystal system is compared at the accelerating voltage range from 40 to 10 kV. Our results show that the CMS method is almost the same as the RRS method for the accelerating voltage above 40 kV. However, when the accelerating voltage is further lowered to 20 kV or below, the CMS method introduces significant errors, not only for the higher-order Laue zone diffractions, but also for zero-order Laue zone. These indicate that the RRS method for non-orthogonal crystal system is necessary to be used for more accurate dynamical simulation when the accelerating voltage is low. Furthermore, the reason for the increase of differences between those diffraction patterns calculated by the RRS method and the CMS method with the decrease of the accelerating voltage is discussed., (© 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.)