Keypoint-Augmented Self-Supervised Learning for Medical Image Segmentation with Limited Annotation

Pretraining CNN models (i.e., UNet) through self-supervision has become a powerful approach to facilitate medical image segmentation under low annotation regimes. Recent contrastive learning methods encourage similar global representations when the same image undergoes different transformations, or enforce invariance across different image/patch features that are intrinsically correlated. However, CNN-extracted global and local features are limited in capturing long-range spatial dependencies that are essential in biological anatomy. To this end, we present a keypoint-augmented fusion layer that extracts representations preserving both short- and long-range self-attention. In particular, we augment the CNN feature map at multiple scales by incorporating an additional input that learns long-range spatial self-attention among localized keypoint features. Further, we introduce both global and local self-supervised pretraining for the framework. At the global scale, we obtain global representations from both the bottleneck of the UNet, and by aggregating multiscale keypoint features. These global features are subsequently regularized through image-level contrastive objectives. At the local scale, we define a distance-based criterion to first establish correspondences among keypoints and encourage similarity between their features. Through extensive experiments on both MRI and CT segmentation tasks, we demonstrate the architectural advantages of our proposed method in comparison to both CNN and Transformer-based UNets, when all architectures are trained with randomly initialized weights. With our proposed pretraining strategy, our method further outperforms existing SSL methods by producing more robust self-attention and achieving state-of-the-art segmentation results. The code is available at https://github.com/zshyang/kaf.git.Comment: Camera ready for NeurIPS 2023. Code available at https://github.com/zshyang/kaf.gi

Excess DHA Induces Liver Injury via Lipid Peroxidation and Gut Microbiota-Derived Lipopolysaccharide in Zebrafish

Being highly unsaturated, n-3 long-chain polyunsaturated fatty acids (LC-PUFAs) are prone to lipid peroxidation. In this study, zebrafish were fed with low-fat diet (LFD), high-fat diet (HFD), or 2% DHA-supplemented HFD (HFDHA2.0). To study the possible negative effects of the high level of dietary DHA, growth rates, blood chemistry, liver histology, hepatic oxidative stress, apoptosis, and inflammatory processes were assessed. The cell studies were used to quantify the effects of DHA and antioxidant on cellular lipid peroxidation and viability. The possible interaction between gut microbiota and zebrafish host was evaluated in vitro. HFDHA2.0 had no effect on hepatic lipid level but induced liver injury, oxidative stress, and hepatocellular apoptosis, including intrinsic and death receptor-induced apoptosis. Besides, the inclusion of 2% DHA in HFD increased the abundance of Proteobacteria in gut microbiota and serum endotoxin level. In the zebrafish liver cell model, DHA activated intrinsic apoptosis while the antioxidant 4-hydroxy-Tempo (tempo) inhibited the pro-apoptotic negative effects of DHA. The apoptosis induced by lipopolysaccharide (LPS) was unaffected by the addition of tempo. In conclusion, the excess DHA supplementation generates hepatocellular apoptosis-related injury to the liver. The processes might propagate along at least two routes, involving lipid peroxidation and gut microbiota-generated LPS

DHA Suppresses Hepatic Lipid Accumulation via Cyclin D1 in Zebrafish

With the widespread use of high-fat diets (HFDs) in aquaculture, fatty livers are frequently observed in many fish species. The aim of this study was to investigate if docosahexaenoic acid (DHA) could be used to reduce the fatty liver in zebrafish generated by a 16% soybean oil-HFD over 2 weeks of feeding. The DHA was added to iso-lipidic HFD at 0.5, 1.0, and 2.0% of diet. Supplementation of DHA reduced growth and feed efficiency in a dose dependent manner being lowest in the HFDHA2.0 group. Hepatic triglyceride (TG) in zebrafish fed 0.5% DHA-supplemented HFD (HFDHA0.5) was significantly lower than in the HFD control. Transcriptional analyses of hepatic genes showed that lipid synthesis was reduced, while fatty acid β-oxidation was increased in the HFDHA0.5 group. Furthermore, the expression of Cyclin D1 in liver of zebrafish fed HFDHA0.5 was significantly reduced compared to that in fish fed HFD. In zebrafish liver cells, Cyclin D1 knockdown and blocking of Cyclin D1-CDK4 signal led to inhibited lipid biosynthesis and elevated lipid β-oxidation. Besides, DHA-supplemented diet resulted in a rich of Proteobacteria and Actinobacteriota in gut microbiota, which promoted lipid β-oxidation but did not alter the expression of Cyclin D1 in germ-free zebrafish model. In conclusion, DHA not only inhibits hepatic lipid synthesis and promotes lipid β-oxidation via Cyclin D1 inhibition, but also facilitates lipid β-oxidation via gut microbiota. This study reveals the lipid-lowering effects of DHA and highlights the importance of fatty acid composition when formulating fish HFD.publishedVersio

Use of probiotics in aquaculture of China—a review of the past decade

China is the largest aquaculture producer in the world. Antibiotics were extensively used to ensure the development of the intensive aquaculture; however, the use of antibiotics causes safety- and environment-associated problems. As an alternative strategy to antibiotics, aquatic probiotics have attracted attention. The microbial organisms used as probiotics or tested as potential probiotics in Chinese aquaculture belong to various taxonomic divisions, including Actinobacteria, Bacteroidetes, Firmicutes, Proteobacteria and yeast. Moreover, the mixture of probiotic strains and synbiotics are also widely used. Studies on the mode of action of aquatic probiotics have extended our understanding of the probiotic effects, and novel mechanisms have been discovered, such as interference of quorum sensing. However, use of probiotics in Chinese aquaculture is still at an initial stage, and there are potential risks for some probiotic applications in aquaculture. Further regulation and management are required to normalize the production and usage of aquatic probiotics. In this review, we discuss species, effects, and mode of actions of probiotics in Chinese aquaculture since 2008. Challenges and future directions for research are also discussed.acceptedVersion© 2018. This is the authors’ accepted and refereed manuscript to the article. Locked until 13 December 2019 due to copyright restrictions. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0

Dietary SWF® enhanced growth performance and disease resistance in hybrid sturgeon (Acipenser baerii x Acipenser schrenckii) mediated by the gut microbiota

The presence of healthy gut microbiota in the gastrointestinal tract of fish is important for the optimal function of gut, which plays a significant role in the host growth and health. The aim of the present study was to investigate the effect of dietary stress worry free (SWF®) on growth, feed utilization and disease resistance of hybrid sturgeon (Acipenser baerii x Acipenser schrenckii). Sturgeon were fed for three weeks with SWF® supplemented or basal diet. The weight gain and FCR of sturgeon fed on the diet supplemented with SWF® were significantly improved (P<0.05). SWF® supplemented diet provoked an increase in the resistance of sturgeon against A. veronii Hm091 (P=0.09). In terms of gut microbiota, the number of total bacteria, Fusobacteria, Firmicutes, and Proteobacteria were increased significantly in the SWF® group (P<0.05), whereas significant reduction of Actinobacteria was observed in the gut of the SWF® group compared with the control group (P<0.01). Moreover, at the end of the experiment the gut microbiota of sturgeon, were colonized to germ-free (GF) zebrafish for three days. Results indicated that, the expression of growth promoter genes mTOR, MyoD and Myogenin was significantly higher in GF zebrafish colonized with gut microbiota of SWF® group of sturgeon. Furthermore, TGF-β was increased significantly in GF zebrafish colonized with gut microbiota from SWF® group (P<0.01), whereas the expression of TNF-α was significantly decreased (P<0.05). The expression of non-specific immune related genes DEFBL-1, C3a and Lysozyme was significantly increased in GF zebrafish colonized with gut microbiota of sturgeon fed on SWF® (P<0.05). Group of GF zebrafish colonized with gut microbiota of sturgeon fed on SWF® had significantly higher survival rate against A. veronii Hm091 (P<0.05). Our study suggests that, the gut microbiota induced by SWF® played a great role in growth and disease resistance of sturgeon using GF zebrafish model.publishedVersio

Effects of substitution of lard oil and soybean oil with Rhodotorula toruloides biomass on growth, muscle fatty acids, digestive enzyme activities, lipid metabolism, liver and intestinal health, and gut microbiota of zebrafish (Danio rerio)

Microbial oil, as an alternative to fish oil, animal and vegetable oils in aquafeeds, have a great potential to fulfil the high demand for lipid sources in the fast-growing aquaculture. However, their use as a feed ingredient in aquaculture is not common. For that, Rhodotorula toruloides (51.90 % lipid) was used to replace 0.00 % (control), 9.38 % (RT3), 18.75 % (RT6), 37.50 % (RT9), and 56.25 % (RT18) of the lard and soybean oils commonly used in aquaculture in the diet of zebrafish. After 6 weeks of feeding, compared with the control group, (1) the FBW and WGR were significantly increased (p<0.05) in RT9 group, (2) the content of C18:1 and C18:3 fatty acids were increased, while that of C18:0, C18:2, and C20:4 were decreased in the muscle of zebrafish, indicating that the fatty acid content of the feed affect the muscle content of fatty acids, (3) the intestinal lipase activity was markedly elevated in RT9 group (p<0.05), (4) in RT9 and RT18 groups the content of AST was significantly reduced (p<0.05), (5) the content of TAG in the liver was significantly reduced in RT6, RT9 and RT18 groups (p<0.05), probably due to the down-regulation of the lipid synthesis-related gene dgat2 and up-regulation of the lipolysis-related gene ucp2, (6) the expression of il-8 in the intestine was notably downregulated in RT9 and RT18 groups (p<0.05), whereas the expression of inhibitory gene il-10 was significantly upregulated in RT9 group (p<0.05), (7) feeding with R. toruloides reduced the relative abundance of Proteobacteria and Vibrio spp, while increasing the abundance of Firmicutes. In sum, the replacement of R. toruloides at a level of 37.50 % can improve the growth, digestive enzyme activity, liver health and gut microbiota profile of zebrafish fed with high-fat diet and can be used to replace the oil sources from other unsustainable ingredients in aquafeed.publishedVersio

A Critical Review of Laser Shock Peening of Aircraft Engine Components

Article describes how many aviation accidents are caused by the failure of aircraft engine components, and engine blades are especially vulnerable to high-cycle fatigue fracture in severe working environments as well as to impact damage caused by foreign objects. This review provides an overview of the development of LSP for use in treating aircraft engine components over the past three decades, with a brief introduction to the development of high-energy pulsed lasers for LSP

Post-marketing safety surveillance of pneumococcal vaccines: a real-world pharmacovigilance study using the U.S. vaccine adverse event reporting system (VAERS) database

BackgroundPneumococcal vaccines have been utilized in the United States for decades with extensive clinical safety records. However, comprehensive post-marketing pharmacovigilance evaluations for all available types remain lacking. This study aimed to assess adverse events following immunization (AEFI) using the VAERS database and analyze potential associations between adverse events (AEs) and vaccine administration based on VAERS data.MethodsWe retrieved all AEs associated with pneumococcal vaccines recorded in the VAERS database from 1990 through March 2025. Descriptive analyses were conducted to summarize the demographics, clinical characteristics, and vaccination profiles of reported cases. Disproportionality analysis was performed to detect potential safety signals between AEs and vaccine administration.ResultsThe VAERS database documented 157,244 individuals receiving pneumococcal vaccines, with 158,778 doses administered, capturing 632,481 AE reports following vaccination during the study period. Females showed higher AE reporting rates (54.29%) compared to males (36.88%), with the majority of cases (38.20%) occurring in individuals aged &lt; 18 years. Complete recovery (44.20%) and hospitalization (14.94%) were the most common outcomes. Most AEs (77.11%) occurred within 0–30 days post-vaccination (median onset: 0 day). Pneumococcal polysaccharide vaccine (PPSV, 48.92%) and 13-valent pneumococcal conjugate vaccine (PCV13, 27.57%) constituted the predominant vaccine types. Disproportionality analysis identified 929 positive AE signals across 24 system organ classes (SOCs), with injection site erythema [reporting odds ratio (ROR) = 4.24], injection site swelling (ROR = 4.19), and injection site pain (ROR = 2.75) being the most frequent. Designated Medical Event (DME) screening revealed erythema multiforme (n = 398) and product contamination microbial (ROR = 11.25) as key safety signals. General disorders (ROR = 1.73) and skin conditions (ROR = 1.69) were the predominant SOC categories.ConclusionsThis post-marketing surveillance has revealed predominantly non-serious AEs, with most adverse events clustered within 30 days post-vaccination. These observations reinforce the established safety profile of pneumococcal vaccines while emphasizing temporal risk patterns to guide post-vaccination monitoring protocols and risk-benefit evaluations

Microwave assisted low temperature synthesis of MnZn ferrite nanoparticles

MnZnFe2O4ferrite nanoparticles were prepared by co-precipitation method using a microwave heating system at temperature of 100 °C. X-ray diffraction reveals the samples as prepared are pure ferrite nanocrystalline phase, transmission electron microscopy image analysis shows particles are in agglomeration state with an average size of about 10 nm, furthermore, crystal size of samples are increased with longer microwave heating