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For deep learning networks used to segment organs at risk (OARs) in head and neck (H&N) cancers, the class-imbalance problem between small volume OARs and whole computed tomography (CT) images results in delineation with serious false-positives on irrelevant slices and unnecessary time-consuming calculations. To alleviate this problem, a slice classification model-facilitated 3D encoder–decoder network was developed and validated. In the developed two-step segmentation model, a slice classification model was firstly utilized to classify CT slices into six categories in the craniocaudal direction. Then the target categories for different OARs were pushed to the different 3D encoder–decoder segmentation networks, respectively. All the patients were divided into training (n  = 120), validation (n  = 30) and testing (n  = 20) datasets. The average accuracy of the slice classification model was 95.99%. The Dice similarity coefficient and 95% Hausdorff distance, respectively, for each OAR were as follows: right eye (0.88 ± 0.03 and 1.57 ± 0.92 mm), left eye (0.89 ± 0.03 and 1.35 ± 0.43 mm), right optic nerve (0.72 ± 0.09 and 1.79 ± 1.01 mm), left optic nerve (0.73 ± 0.09 and 1.60 ± 0.71 mm), brainstem (0.87 ± 0.04 and 2.28 ± 0.99 mm), right temporal lobe (0.81 ± 0.12 and 3.28 ± 2.27 mm), left temporal lobe (0.82 ± 0.09 and 3.73 ± 2.08 mm), right temporomandibular joint (0.70 ± 0.13 and 1.79 ± 0.79 mm), left temporomandibular joint (0.70 ± 0.16 and 1.98 ± 1.48 mm), mandible (0.89 ± 0.02 and 1.66 ± 0.51 mm), right parotid (0.77 ± 0.07 and 7.30 ± 4.19 mm) and left parotid (0.71 ± 0.12 and 8.41 ± 4.84 mm). The total segmentation time was 40.13 s. The 3D encoder–decoder network facilitated by the slice classification model demonstrated superior performance in accuracy and efficiency in segmenting OARs in H&N CT images. This may significantly reduce the workload for radiation oncologists. [ABSTRACT FROM AUTHOR]

Background and Objective: Heavy ion radiation is one of the major hazards astronauts face during space expeditions, adversely affecting the central nervous system. Radiation causes severe damage to sensitive brain regions, especially the striatum, resulting in cognitive impairment and other physiological issues in astronauts. However, the intensity of brain damage and associated underlying molecular pathological mechanisms mediated by heavy ion radiation are still unknown. The present study is aimed to identify the damaging effect of heavy ion radiation on the striatum and associated underlying pathological mechanisms., Materials and Methods: Two parallel cohorts of rats were exposed to radiation in multiple doses and times. Cohort I was exposed to 15 Gy of 12 C 6+ ions radiation, whereas cohort II was exposed to 3.4 Gy and 8 Gy with 56 Fe 26+ ions irradiation. Physiological and behavioural tests were performed, followed by 18 F-FDG-PET scans, transcriptomics analysis of the striatum, and in-vitro studies to verify the interconnection between immune cells and neurons., Results: Both cohorts revealed more persistent striatum dysfunction than other brain regions under heavy ion radiation at multiple doses and time, exposed by physiological, behavioural, and 18 F-FDG-PET scans. Transcriptomic analysis revealed that striatum dysfunction is linked with an abnormal immune system. In vitro studies demonstrated that radiation mediated diversified effects on different immune cells and sustained monocyte viability but inhibited its differentiation and migration, leading to chronic neuroinflammation in the striatum and might affect other associated brain regions., Conclusion: Our findings suggest that striatum dysfunction under heavy ion radiation activates abnormal immune systems, leading to chronic neuroinflammation and neuronal injury., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Chen, Li, Rasheed, Wang, Lei, Zhao, Deng and Ma.)

Extracellular vesicles (EVs) are hemispherical vesicles that have a lipid bilayer. Studies have shown that EVs have important biological functions. The amount, types, and compositional changes of proteins, lipids and ribonucleic acids are closely related to diseases. The separation and capture of EVs from the complicated body fluid samples is a prerequisite for medical research and liquid biopsy based on EVs. However, presently the majority of EVs separation and capture still use the traditional separation methods with low purity and low efficiency. Therefore, efficient and highly selective EVs separation method is in urgent need. To meet this challenge, advanced microfluidic chip technology, which has the advantages of miniaturization, integration, and automation, can be utilized. The development of EV separation technology combined with microfluidic chips has become the focus of research. This paper summarizes the latest research progress in this area.

The widespread application of TiO2 nanoparticles (NPs) as additives in foods such as gum, candy and puddings has dramatically increased the human ingestion and accumulation of these nanomaterials. Although the toxicity of TiO2 NPs has been extensively studied, their impact on gut microbiota in vivo still needs further research. In this study, TiO2 NPs with two main crystalline phases anatase and rutile were orally administrated to mice for 28 days. The dynamic influences of anatase and rutile on gut microbiota structures were investigated at doses equivalent to those consumed by people who love to eat candies. The results showed that titanium accumulated in the spleen, lung, and kidney but had no significant effects on organ histology. Gavage of rutile NPs but not anatase NPs resulted in longer intestinal villi and irregular arrangement of villus epithelial cells. Treatment with TiO2 NPs did not decrease gut microbiota diversity but shifted their structures in a time-dependent manner. Rutile NPs had a more pronounced influence on the gut microbiota than anatase NPs. The most influenced phylum was Proteobacteria, which was significantly increased by rutile but not by anatase. At the genus level, Prevotella was significantly decreased by both the TiO2 NPs, Rhodococcus was enriched by rutile NPs, and Bacteroides was increased by anatase NPs. Overall, these results suggested that chronic overconsumption of TiO2 NP-containing foods is likely to deteriorate the gastrointestinal tract and change the structures of microbiota. The crystalline phases may play an important role in mediating the intestinal impact of TiO2 NPs.