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This study aimed to develop a novel electrode to achieve balance between anastomotic strength and tissue thermal damage for radiofrequency-induced intestinal anastomosis. Methods: The mechanical properties of the novel electrode were analyzed by finite element method, and then the temperature and thermal damage distribution of intestinal tissue during welding process were analyzed by electric-thermalmechanical multi-field coupled finite element analysis. In ex vivo experiments, the biomechanical strength of anastomotic area was assessed by indexes of tensile force and burst pressure. A thermocouple probe and an infrared thermal imager were used to monitor the temperature and thermal damage of the intestinal tissue in experiments. Furthermore, histopathological examination and transmission electron microscopy observation were used to observe the morphology and microstructure of anastomotic area. Results: A slightly higher mean biomechanical strength is acquired with the tensile force and burst pressure results increasing from 9.7 ± 1.47 N, 84.0 ± 5.99 mmHg to 11.8 ± 2.01 N, 89.6 ± 6.79 mmHg, respectively, as well as the percentage of necrotic tissue caused by thermal damage decreasing from 89% to 33% for the novel electrode group, with compression force of 20 N, radiofrequency (RF) energy of 120 W and welding duration of 8 s applied to the target regions to achieve anastomosis. Moreover, tightly connected intestinal tissue with collagenic crosslink in the fusion area could be observed by histopathological examination and transmission electron microscopy. Conclusions: Our study shows that the proposed novel electrode could achieve balance between anastomotic strength and tissue thermal damage for radiofrequencyinduced intestinal anastomosis. [ABSTRACT FROM AUTHOR]

Precompression is vital when performing gastrointestinal anastomosis with staplers. However, research on the internal changes in intestinal tissue under stapling is lacking, and the effects of precompression have not been clarified. In this study, a stapler was modified, and the multifrequency bioimpedance of porcine small intestinal tissue was measured from before clamping the tissue with the stapler until the release of the tissue after precompression without firing. The Cole Y model was fitted to the bioimpedance, and the changes in the tissue were analyzed using the model parameters: G0, extracellular fluid conductance, and Δ G, intracellular fluid conductance. The results show that the changes of G0 and Δ G could be divided into four stages: rapid decrease, slow decrease, intense resilience, and slow recovery. During slow decrease stage, there was a greater decrease of G0 and Δ G (1.02E-05 ± 1.12E-05 S and 1.73E-05 ± 2.12E-05 S in precompression time's increase, 1.68E-05 ± 8.74E-06 S and 1.20E-05 ± 1.09E-05 S in precompression strength's increase). On the contrary, during intense resilience stage, there was a less increase of G0 and Δ G (0.88E-05 ± 4.86E-05 S and 9.15E-05 ± 9.37E-05 S in precompression time's increase, 2.72E-05 ± 3.53E-05 S and 1.02E-04 ± 8.54E-05 S in precompression strength's increase). In conclusion, the effects of precompression factors on tissue have been preliminary revealed: the tissue under precompression becomes thinner and less resilient. To improve the precompression effects and reduce any excessive pressure exerted on the staples by tissue resilience, the precompression time and strength should be increased appropriately. [ABSTRACT FROM AUTHOR]

The Alternating current (AC) induced corrosion of pipeline steel was investigated in near-neutral pH carbonate/bicarbonate solution by potentiodynamic technique and weight loss test. It is found that superimposed AC is able to cause the negative shift of corrosion potential of pipeline steel, the severity of the polarization curve oscillation is proportional to the ratio of AC current density to DC current density, the most severe oscillation can be observed in the region near corrosion potential. The results of weight loss test indicated that the greater AC current density resulted in the higher AC-induced corrosion rate. The corrosion morphology viewed by optical camera and SEM showed that the form of corrosion is closely related to the magnitude of AC current density. [ABSTRACT FROM AUTHOR]

Microsomal cytochrome b is a ubiquitous, 15.2 kDa haemoprotein implicated in a number of cellular processes such as fatty acid desaturation, drug metabolism, steroid hormone biosynthesis and methaemoglobin reduction. As a consequence of these functions this protein has been considered essential for life. Most of the ascribed functions of cytochrome b, however, stem from in vitro studies and for this reason we have carried out a germline deletion of this enzyme. We have unexpectedly found that cytochrome b null mice were viable and fertile, with pups being born at expected Mendelian ratios. However, a number of intriguing phenotypes were identified, including altered drug metabolism, methaemoglobinemia and disrupted steroid hormone homeostasis. In addition to these previously identified roles for this protein, cytochrome b null mice displayed skin defects closely resembling those observed in autosomal recessive congenital ichthyosis and retardation of neonatal development, indicating that this protein, possibly as a consequence of its role in the de novo biosynthesis of unsaturated fatty acids, plays a central role in skin development and neonatal nutrition. Results from fatty acid profile analysis of several tissues suggest that cytochrome b plays a role controlling saturated/unsaturated homeostasis. These data demonstrate that regional concentrations of unsaturated fatty acids are controlled by endogenous metabolic pathways and not by diet alone. [ABSTRACT FROM AUTHOR]

Existing deep-learning-based pulmonary nodule classification models usually use images and benign-malignant labels as inputs for training. Image attributes of the nodules, as human-nameable high-level semantic labels, are rarely used to build a convolutional neural network (CNN). In this paper, a new method is proposed to combine the advantages of two classifications, which are pulmonary nodule benign-malignant classification and pulmonary nodule image attributes classification, into a deep learning network to improve the accuracy of pulmonary nodule classification. For this purpose, a unique 3D CNN is built to learn image attribute and benign-malignant classification simultaneously. A novel loss function is designed to balance the influence of two different kinds of classifications. The CNN is trained by a publicly available lung image database consortium (LIDC) dataset and is tested by a cross-validation method to predict the risk of a pulmonary nodule being malignant. This proposed method generates the accuracy of 91.47%, which is better than many existing models. Experimental findings show that if the CNN is built properly, the nodule attributes classification and benign-malignant classification can benefit from each other. By using nodule attribute learning as a control factor in a deep learning scheme, the accuracy of pulmonary nodule classification can be significantly improved by using a deep learning scheme. [ABSTRACT FROM AUTHOR]

Quantitative assessment of mammographic asymmetry has been investigated for breast cancer risk prediction. A new asymmetry feature extraction method was proposed in this study to enhance the risk prediction accuracy of near-term breast cancer. Breast areas in each pair of bilateral mammographic images were divided into several pairs of matched local annular regions and the maximum local asymmetry features (MLAF) were extracted from these regions. Radial basis function network (RBFN) was used to merge these features for breast cancer risk prediction. The dataset included 560 negative subjects. The risk prediction performance was tested using a leave-one-case-out (LOCO) cross-validation method. Area under the receiver operating characteristic curve (AUC) was used as the risk prediction performance evaluation index. AUC  =  0.898  ±  0.013 was obtained by using the MLAFs extracted from the annular regions, which was significantly higher than the AUC value of 0.505  ±  0.025 achieved by using global asymmetry features computed from the whole breast regions (p  <  0.05, DeLong's test) and much higher than the AUC values of 0.825  ±  0.017 and 0.717  ±  0.021 achieved by using MLAFs extracted from horizontal strip regions and vertical strip regions. The study demonstrated that near-term breast cancer risk prediction could be improved by using the proposed feature extraction method. [ABSTRACT FROM AUTHOR]

The present study investigates the relationship between bio-impedance and burst pressure of colorectal anastomosis created by radiofrequency (RF)-induced tissue fusion. Colorectal anastomosis were created with ex vivo porcine colorectal segments, during which 5 levels of compression pressure were applied by a custom-made bipolar prototype, with 5 replicate experiments at each compression pressure. Instant anastomotic tensile strength was assessed by burst pressure. Bio-impedance of fused tissue was measured by Impedance Analyzer across frequency that 100 Hz to 3 MHz. Statistical analysis shows only a weak correlation between bio-impedance modulus and burst pressures at frequency of 445 kHz (  =  −0.426, P  =  0.099  >  0.05). In contrast, results demonstrated a highly significant negative correlation between reactance modulus and burst pressures (  =  −0.812, P  =  0.000  <  0.05). The decrease in mean reactance modulus with increasing burst pressures was highly significant (P  =  0.019  <  0.05). The observed strong negative correlation between reactance modulus and burst pressures at frequency of 445 kHz indicates that reactance is likely to be a good index for tensile strength of RF-induced colorectal anastomosis, and should be considered for inclusion in a feedback loops in devices design. [ABSTRACT FROM AUTHOR]

A fiber confocal backscattering (FCBS) spectrometer is developed based on fiber confocal microscopy and light scattering theory. The FCBS spectrometer can provide imaging and spectral information simultaneously at the cellular scale. Normal stomach epithelial cell line GES-1 and cancerous cell line NCI-N87 are measured and their spectral results show that backscattering intensity from NCI-N87 cells is stronger than that from GES-1 cells in 500 to 800 nm, and the GES-1 cells scattering spectra show regular intensity changes, while the NCI-N87 cells do not. The experiments prove that the FCBS spectrometer is able to distinguish cancerous cells from normal stomach cells at the cellular level. The spectrometer could be further developed into a noninvasive optical technology for early cancer detection. [ABSTRACT FROM AUTHOR]