Lightweight MRI Brain Tumor Segmentation Enhanced by Hierarchical Feature Fusion.

BACKGROUND: Existing methods for MRI brain tumor segmentation often suffer from excessive model parameters and suboptimal performance in delineating tumor boundaries. METHODS: For this issue, a lightweight MRI brain tumor segmentation method, enhanced by hierarchical feature fusion (EHFF), is proposed. This method reduces model parameters while improving segmentation performance by integrating hierarchical features. Initially, a fine-grained feature adjustment network is crafted and guided by global contextual information, leading to the establishment of an adaptive feature learning (AFL) module. This module captures the global features of MRI brain tumor images through macro perception and micro focus, adjusting spatial granularity to enhance feature details and reduce computational complexity. Subsequently, a hierarchical feature weighting (HFW) module is constructed. This module extracts multi-scale refined features through multi-level weighting, enhancing the detailed features of spatial positions and alleviating the lack of attention to local position details in macro perception. Finally, a hierarchical feature retention (HFR) module is designed as a supplementary decoder. This module retains, up-samples, and fuses feature maps from each layer, thereby achieving better detail preservation and reconstruction. RESULTS: Experimental results on the BraTS 2021 dataset demonstrate that the proposed method surpasses existing methods. Dice similarity coefficients (DSC) for the three semantic categories ET, TC, and WT are 88.57%, 91.53%, and 93.09%, respectively.

Compact plasmon modulator with a high extinction ratio.

To keep pace with the demands in optical communications, electro-optic modulators should feature a high extinction ratio, offer a small footprint, and allow for practical detection. Herein, we demonstrate a compact plasmon modulator with a high extinction ratio where a compact modulation region composed of indium tin oxide (ITO) is embedded to the arms of the Mach-Zehnder (M-Z) interferometer. The modulator has a footprint of 20µm×12µm with a modulation region of 4µm×0.5µm. The numerical results show that the extinction ratio is 15.2 dB when the electron concentration of ITO is changed 4×1020cm-3. This type of modulator paves the way for future compact optoelectronic integration and has potential application in the fields of optical communication, photodetection, and sensing.

Distributed Robust Fault Estimation Using Relative Measurements for Leader-Follower Multiagent Systems.

In this article, the problem of distributed robust fault estimation (FE) for leader-follower multiagent systems using relative measurements is considered. A distributed intermediate-based fault estimator is constructed using the local relative measurements and the state estimation from neighbors. The gain matrices of the fault estimator are calculated based on H∞ performance in terms of linear matrix inequality (LMI) to improve the robustness of the estimator. Then, the LMI is separated and simplified by spectral decomposition, and its equivalent condition is proposed based on the maximum and minimum eigenvalue. A distributed eigenvalue estimation algorithm based on the power method is presented to fully distribute the proposed FE scheme. Finally, the numerical simulations are provided to verify the effectiveness of the proposed scheme.

[Retracted] Effects of the eukaryotic initiation factor 6 gene on expression levels of inflammatory mediators in M2 macrophages during scar repair.

Following the publication of this article, we regret to report that we have been unable to reproduce the results presented in the paper in our subsequent studies. At the present time, we have not been able to ascertain the reason behind this. Therefore, we would like to retract this article from publication. All the named authors agree to this retraction. We regret any inconvenience to the readers that this retraction will cause. [The original article was published in Molecular Medicine Reports 14: 819-824, 2016; DOI: 10.3892/mmr.2016.5294].

Modeling and evaluation of the oil-spill emergency response capability based on linguistic variables.

An evaluation of the oil-spill emergency response capability (OS-ERC) currently in place in modern marine management is required to prevent pollution and loss accidents. The objective of this paper is to develop a novel OS-ERC evaluation model, the importance of which stems from the current lack of integrated approaches for interpreting, ranking and assessing OS-ERC performance factors. In the first part of this paper, the factors influencing OS-ERC are analyzed and classified to generate a global evaluation index system. Then, a semantic tree is adopted to illustrate linguistic variables in the evaluation process, followed by the application of a combination of Fuzzy Cognitive Maps (FCM) and the Analytic Hierarchy Process (AHP) to construct and calculate the weight distribution. Finally, considering that the OS-ERC evaluation process is a complex system, a fuzzy comprehensive evaluation (FCE) is employed to calculate the OS-ERC level. The entire evaluation framework obtains the overall level of OS-ERC, and also highlights the potential major issues concerning OS-ERC, as well as expert opinions for improving the feasibility of oil-spill accident prevention and protection.

Effects of the eukaryotic initiation factor 6 gene on expression levels of inflammatory mediators in M2 macrophages during scar repair.

The aim of the present study was to evaluate the effects of the eukaryotic initiation factor 6 (eIF6) gene on the secretion of M2 macrophage fibrosis­associated factors and the expression levels of key proteases during scar repair. Male eIF6 wild­type (eIF6+/+) and knockout (eIF6+/­) C57BL/6 mice were intraperitoneally lavaged to obtain macrophages, which were induced to the M2 type using interleukin­4. Differences between the gene expression profiles of these macrophages were compared with gene microarrays, and the results were validated using reverse transcription-quantitative polymerase chain reaction analysis and ELISA. Compared with the eIF6+/­ mice, the mRNA and protein expression levels of vascular endothelial growth factor (VEGF) and tissue inhibitor of metalloproteinase­2 (TIMP­2) in the M2 macrophages of the eIF6+/+ mice were significantly downregulated (P<0.05), whereas the mRNA and protein expression levels of matrix metalloproteinase­2 (MMP­2) were significantly upregulated (P<0.05). Therefore, the results indicated that eIF6 alleviated cicatrization, possibly by inhibiting the generation of VEGF, in order to prevent overgrowth of blood vessels and granulation tissues, and to regulate the MMP-2/TIMP-2 ratio to balance the degradation and deposition of the extracellular matrix.

[Clinical effect of the concentrated suture fixation method on skin transplantation in the jaw and neck region].

OBJECTIVE: To observe the clinical effect of the concentrated suture fixation method on skin transplantation on deep burn wound or wound of cicatricial deformity after burn in the jaw and neck region. METHODS: One hundred and fourteen patients, hospitalized from April 2002 to December 2011, with deep burn or cicatricial deformity after burn in the jaw and neck region, were divided into packaging group and concentrated suture group according to the random number table. Each group had 57 patients including 48 cases with deep burn and 9 cases with cicatricial deformity. Traditional suture-package fixation method and concentrated suture fixation method were respectively used in packaging group and concentrated suture group to fix the autologous medium split-thickness skin in transplantation on wounds or scars. On post operation day (POD) 14, the skin microcirculatory perfusion flow of skin graft was measured, and the occurrence of ecchymoma, infection, and necrosis of skin in operative region were observed. The elasticity and contracture of grafted skin and scar hyperplasia on wound edge were observed 6 months after operation. Measurement data were processed with u test, while enumeration data with Fisher's exact test or Chi-square test. RESULTS: (1) On POD 14, the skin microcirculatory perfusion flow in concentrated suture group [(2.86 +/- 0.8) V] was significantly higher than that in packaging group [(2.33 +/- 0.15) V, u = 17.776, P < 0.05]. (2) Ecchymoma occurred in 4 patients of packaging group and 3 patients of concentrated suture group, but the difference between two groups was not statistically significant (chi 2 = 0.152, P > 0.05). (3) Infection in operative region was observed in 1 patient of packaging group, while no patient in concentrated suture group showed this symptom. The difference between two groups was not statistically significant (P > 0.05). (4) Grafted skin in 6 patients of packaging group showed foliated necrosis, which was not observed on those of patients in concentrated suture group. The difference between two groups was statistically significant (P < 0.05). (5) Centipede leg-like scar hyperplasia on wound edge occurred in 21 patients in packaging group and 6 patients in concentrated suture group, and the difference between two groups was statistically significant (chi 2 = 10.920, P < 0.05). (6) Poor elasticity of grafted skin was detected in 17 patients of packaging group and 4 patients of concentrated suture group, and the difference between two groups was statistically significant (chi 2 = 9.865, P < 0.05). (7) Obvious contracture of grafted skin was observed in 15 patients of packaging group and 4 patients of concentrated suture group, and the difference between two groups was statistically significant (chi 2 = 11.684, P < 0.05). CONCLUSIONS: Concentrated suture fixation method is suitable for application in transplantation of big sheet skin on wound in the jaw and neck region. It has high survival rate and is convenient for postoperative observation.

[Dynamic change in microcirculation of pancreas after experimental high-voltage electric burn].

OBJECTIVE: To observe the changes in surface microcirculation of pancreas after high-voltage electric burn (HEB). METHODS: Thirty rabbits were divided into electrical injury (E) group and control (C) group in a simple random method, with 15 rabbits in each group. Rabbit model of HEB was reproduced from E group with TC-30-20KVA type voltage regulator and YDJ-10KVA type experimental transformer. Rabbits in C group were shamly burned with the same equipment as in E group but not electrified. Intravenous blood of rabbits in both groups was drawn 15 mins before HEB and 0, 1, 2, 4, 8 h after to determine the levels of serum amylase and blood glucose. The morphology of the pancreas microvessels and its surrounding tissues, and the dynamic changes in microvascular blood flow were observed with WX-9 microscope and its image analytical system. RESULTS: The level of serum amylase of rabbits in E group increased gradually and peaked (849 +/- 39) U/L at 8 post HEB h (PHH), which decreased gradually reaching the nadir (153 +/- 21) U/L at 8 PHH in C group (P < 0.05). The blood glucose levels of rabbits in E group and C group increased gradually, with the former level obviously higher than the latter (P < 0.05). Arteriole, venule and capillary network on the surface of pancreatic lobules of rabbits in both groups were clearly seen and well-distributed in the natural way before HEB. In E group, arterioles of rabbits contracted at 0 PHH, and increased gradually in caliber size at 1 PHH; venules of rabbits were unevenly thickened at 2 PHH, and dilated at 8 PHH; the capillaries were contracted or with interrupted flow or completely obstructed at 0 PHH, and their thickness were uneven at 2 PHH, showing exudation at 8 PHH. There was no obvious change of microvessels in rabbits in C group at each time point. There was no exudation and bleeding around the microvessels on the pancreas surface of rabbits in both groups before HEB. In E group exudation was observed around microvessels at 1 PHH, bleeding was observed at 2 PHH and became obvious at 4 PHH; exudation and diffuse bleeding from capillaries were observed at 8 PHH. There was no exudation and bleeding in rabbits in C group as observed at each time point. Before HEB, blood flow speed in microvessels of rabbits in 2 groups was similar to each other (P > 0.05), and no erythrocyte aggregation or microthrombus was found in both groups. In E group, blood flow speed slowed down at 0 PHH as compared with that before HEB, it accelerated at 1 h and slowed down later; erythrocyte aggregation in venules and capillaries was found at 0 PHH, and it aggregated gradually. No above-mentioned change was found in C group. CONCLUSIONS: HEB produces microcirculation disturbance and functional disturbance of pancreas.