Aiming at the detection of surface defects of train bearing rollers, a set of surface defect detection systems for bearing cylindrical rollers based on machine vision is designed in this paper, and ...the vibration response of the roller during the rolling process is simulated and analyzed. The surface image of the cylindrical roller is obtained by using the area scan camera, and the region of interest is extracted by using edge extraction and template matching algorithm to obtain the cylindrical roller image without background interference. The roller cylinder images are spliced by feature matching and regional fusion methods, and the roller surface defects are extracted by OTSU threshold segmentation, Canny operator edge detection and morphological processing, so as to mark the defects for distinction and identification. The method achieves the purpose of quickly identifying the roller surface defects and rejecting the cylindrical rollers with defective surfaces in train bearings. It provides a theoretical basis for the automation and intelligence of the cylindrical rollers of train bearings in the process of maintenance and repair.
The present study aimed to determine the occurrence of autophagy following ischemia/reperfusion (I/R) injury in the rat spinal cord and whether autophagy inhibition contributes to neural tissue ...damage and locomotor impairment. A spinal cord I/R model was induced via descending thoracic aorta occlusion for 10 min using systemic hypotension (40 mmHg) in adult male Sprague-Dawley rats. Then, 600 nmol 3-methyladenine (3-MA) or vehicle was intrathecally administered. Ultrastructural spinal cord changes were observed via transmission electron microscopy (TEM) and immunofluorescent double-labeling. Western blots were used to determine the protein expression of microtubule-associated protein light chain 3 (LC3) and Beclin 1. Autophagy was activated after spinal cord I/R injury as demonstrated by significantly increased LC3 and Beclin 1 expression at 3–48 h after injury. Furthermore, TEM images indicated the presence of autophagosomes and autolysosomes in the injured spinal cord. 3-MA significantly decreased LC3 and Beclin 1 expression and the number of LC3-positive cells in spinal cord of I/R versus vehicle groups. Moreover, the 3-MA-treated rats exhibited better neurobehavioral scores compared with control rats. These findings suggest activation of autophagy leading to neuronal cell death in the I/R injured spinal cord. These effects were significantly inhibited by intrathecal 3-MA administration. Thus intrathecal 3-MA administration may represent a novel treatment target following spinal cord I/R injury.
Quaternized poly(phthalazinone ether ketone)s (QPPEK)s were synthesized by the chloromethylation and quaternization of poly(phthalazinone ether ketone) (PPEK) with chloromethyl methyl ether in 98% ...concentrated sulfuric acid and following trimethylamine. The presence of ---CH₂Cl groups in chloromethylated PPEK was confirmed by ¹H-NMR. An alkaline QPPEK membrane was prepared and its thermal and mechanical properties were tested. The alkaline QPPEK membrane had a methanol permeability 6.57 x 10⁻⁷ cm²/s and the highest anion conductivity 1.14 x 10⁻² S/cm.
To investigate the effect of a three-dimensional (3D) exoscope for decompression of single-segment massive lumbar disc herniation (LDH).
The study included 56 consecutive patients with single segment ...massive LDH who underwent decompression assisted by a 3D exoscope from October 2019 to October 2022 at a university hospital. The analysis was based on comparison of perioperative metrics including decompression time, estimated blood loss (EBL) during decompression and postoperative length of stay (PLS); clinical outcomes including assessment using the visual analogue scale (VAS) and the Oswestry disability index (ODI); and incidence of reoperation and complications.
The mean decompression time was 28.35 ± 8.93 min (lumbar interbody fusion (LIF)) and 15.50 ± 5.84 min (fenestration discectomy (LOVE surgery)), the mean EBL during decompression was 42.65 ± 12.42 ml (LIF) and 24.32 ± 8.61 ml (LOVE surgery), and the mean PLS was 4.56 ± 0.82 days (LIF) and 2.00 ± 0.65 days (LOVE surgery). There were no complications such as cerebrospinal fluid leakage, nerve root injury and epidural hematoma. All patients who underwent decompression assisted by a 3D exoscope were followed up for 6 months. At the last follow-up, the VAS and ODI scores were significantly improved from the preoperative period to the last follow-up (P < 0.05).
A 3D exoscope provides a visually detailed, deep and clear surgical field, which makes decompression safer and more effective and reduces short-term complications. A 3D exoscope may be a good assistance tool during decompression for single-segment massive LDH.
Diabetes mellitus is a systematic disease which exert detrimental effect on bone tissue. The repair and reconstruction of bone defects in diabetic patients still remain a major clinical challenge. ...This study aims to investigate the potential of bone tissue engineering approach to improve bone regeneration under diabetic condition.
In the present study, decalcified bone matrix (DBM) scaffolds were seeded with allogenic fetal bone marrow-derived mesenchymal stem cells (BMSCs) and cultured in osteogenic induction medium to fabricate BMSC/DBM constructs. Then the BMSC/DBM constructs were implanted in both subcutaneous pouches and large femoral bone defects in diabetic (BMSC/DBM in DM group) and non-diabetic rats (BMSC/DBM in non-DM group), cell-free DBM scaffolds were implanted in diabetic rats to serve as the control group (DBM in DM group). X-ray, micro-CT and histological analyses were carried out to evaluate the bone regenerative potential of BMSC/DBM constructs under diabetic condition.
In the rat subcutaneous implantation model, quantitative micro-CT analysis demonstrated that BMSC/DBM in DM group showed impaired bone regeneration activity compared with the BMSC/DBM in non-DM group (bone volume: 46 ± 4.4 mm
vs 58.9 ± 7.15 mm
, *
< 0.05). In the rat femoral defect model, X-ray examination demonstrated that bone union was delayed in BMSC/DBM in DM group compared with BMSC/DBM in non-DM group. However, quantitative micro-CT analysis showed that after 6 months of implantation, there was no significant difference in bone volume and bone density between the BMSC/DBM in DM group (199 ± 63 mm
and 593 ± 65 mg HA/ccm) and the BMSC/DBM in non-DM group (211 ± 39 mm
and 608 ± 53 mg HA/ccm). Our data suggested that BMSC/DBM constructs could repair large bone defects in diabetic rats, but with delayed healing process compared with non-diabetic rats.
Our study suggest that biomaterial sacffolds seeded with allogenic fetal BMSCs represent a promising strategy to induce and improve bone regeneration under diabetic condition.
Bacterial colony counting is a time consuming but important task for many fields, such as food quality testing and pathogen detection, which own the high demand for accurate on-site testing. However, ...bacterial colonies are often overlapped, adherent with each other, and difficult to precisely process by traditional algorithms. The development of deep learning has brought new possibilities for bacterial colony counting, but deep learning networks usually require a large amount of training data and highly configured test equipment. The culture and annotation time of bacteria are costly, and professional deep learning workstations are too expensive and large to meet portable requirements. To solve these problems, we propose a lightweight improved YOLOv3 network based on the few-shot learning strategy, which is able to accomplish high detection accuracy with only five raw images and be deployed on a low-cost edge device. Compared with the traditional methods, our method improved the average accuracy from 64.3% to 97.4% and decreased the False Negative Rate from 32.1% to 1.5%. Our method could greatly improve the detection accuracy, realize the portability for on-site testing, and significantly save the cost of data collection and annotation over 80%, which brings more potential for bacterial colony counting.
LiFePO₄/C composite with carbon content of 5wt.% was synthesized by solid state reaction. Core-shell structure was confirmed by scanning electron microscope (SEM) and transmission electron microscopy ...(TEM). Rechargeable Lithium ion battery based on this compound has reached a high rate capacity of 121.5mAhg⁻¹ under 5C. The rate capability retention between 0.1C and 5C is 86.9%, which is the highest as far as we know. We found the carbon content was 12.7% on the surface of LiFePO₄ grain, although the whole carbon content was about 5wt.%. We attribute the improvement of rate capability retention to the existence of the carbon rich surface.
An important way to obtain PbS and FeS is the thermal decomposition of Jamesonite. However, the mechanism of PbS–FeS interaction is unknown. In order to explore the separation effect of PbS and FeS, ...thermodynamic calculation, dynamic simulation and vacuum distillation experiments were used to explore the interaction mechanism of PbS and FeS. The decomposition and volatilization temperatures of PbS and FeS were obtained by thermodynamic calculation. The difference of saturated vapor pressure indicates that there is a tendency of separation between them. The ab initio molecular dynamics method was used to calculate the density of states of PbS and FeS at different temperatures, indicating that the FeS(114) structure is more stable than the PbS(200) structure, and the Pb–S bond is easier to break than the Fe–S bond at the same temperature. The experimental results of vacuum distillation show that the volatilization temperature of PbS is much lower than that of FeS, and FeS can only volatilize into the gas phase at a higher temperature. The theoretical calculation method is consistent with the experimental results, which shows that the thermodynamic calculation and dynamic simulation methods are reliable in predicting the volatilization and separation of crystal structures. The interaction mechanism between PbS and FeS was explored from the theoretical point of view to provide theoretical guidance for vacuum distillation experiment.
Single-cell RNA sequencing (scRNA-seq) is a powerful tool for studying transcriptomics. Here, we present an optimized protocol for dissociating human scalp tissue and acquiring high-quality ...single-cell suspension for scRNA-seq to study transcriptomics of human hair follicles. We describe steps for human scalp tissue cleaning, subcutaneous fat removal, mechanical mincing, and enzymatic digestion. We then detail procedures for cleaning, resuspending, a cell viability assay, and library construction.
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•Dissociation protocol for full-thickness human scalp tissue•Mechanical mincing and enzymatic digestion•High-throughput single-cell RNA library preparation
Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics.
Single-cell RNA sequencing (scRNA-seq) is a powerful tool for studying transcriptomics. Here, we present an optimized protocol for dissociating human scalp tissue and acquiring high-quality single-cell suspension for scRNA-seq to study transcriptomics of human hair follicles. We describe steps for human scalp tissue cleaning, subcutaneous fat removal, mechanical mincing, and enzymatic digestion. We then detail procedures for cleaning, resuspending, a cell viability assay, and library construction.
The Li
0.98Al
0.02FePO
4/C (2.0
wt.%) mix-doped composite had been synthesized by adding aluminum stearate to the react precursors through solid-state reaction. The mix-doping method does not affect ...the olivine structure of the cathode but greatly improves its kinetics in terms of capacity delivery, cycle life and rate capability. Such an enhancement of the electrochemical properties has been ascribed to the increase of intra- and inter-crystal electronic conductivity and the reduction of the particle size, these two effects being promoted by the co-existence of the lattice doping element (Al
3+) and the non-lattice doping element (C). Overcharge test indicates that this composite has excellent safety performances.
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