Enhanced segmentation of gastrointestinal polyps from capsule endoscopy images with artifacts using ensemble learning

BACKGROUND

Endoscopy artifacts are widespread in real capsule endoscopy (CE) images but not in high-quality standard datasets.

AIM

To improve the segmentation performance of polyps from CE images with artifacts based on ensemble learning.

METHODS

We collected 277 polyp images with CE artifacts from 5760 h of videos from 480 patients at Guangzhou First People’s Hospital from January 2016 to December 2019. Two public high-quality standard external datasets were retrieved and used for the comparison experiments. For each dataset, we randomly segmented the data into training, validation, and testing sets for model training, selection, and testing. We compared the performance of the base models and the ensemble model in segmenting polyps from images with artifacts.

RESULTS

The performance of the semantic segmentation model was affected by artifacts in the sample images, which also affected the results of polyp detection by CE using a single model. The evaluation based on real datasets with artifacts and standard datasets showed that the ensemble model of all state-of-the-art models performed better than the best corresponding base learner on the real dataset with artifacts. Compared with the corresponding optimal base learners, the intersection over union (IoU) and dice of the ensemble learning model increased to different degrees, ranging from 0.08% to 7.01% and 0.61% to 4.93%, respectively. Moreover, in the standard datasets without artifacts, most of the ensemble models were slightly better than the base learner, as demonstrated by the IoU and dice increases ranging from -0.28% to 1.20% and -0.61% to 0.76%, respectively.

CONCLUSION

Ensemble learning can improve the segmentation accuracy of polyps from CE images with artifacts. Our results demonstrated an improvement in the detection rate of polyps with interference from artifacts.

Fabrication of Metallic Superhydrophobic Surfaces with Tunable Condensate Self-Removal Capability and Excellent Anti-Frosting Performance

Laser fabrication of metallic superhydrophobic surfaces (SHSs) for anti-frosting has recently attracted considerable attention. Effective anti-frosting SHSs require the efficient removal of condensed microdroplets through self-propelled droplet jumping, which is strongly influenced by the surface morphology. However, detailed analyses of the condensate self-removal capability of laser-structured surfaces are limited, and guidelines for laser processing parameter control for fabricating rationally structured SHSs for anti-frosting have not yet been established. Herein, a series of nanostructured copper-zinc alloy SHSs are facilely constructed through ultrafast laser processing. The surface morphology can be properly tuned by adjusting the laser processing parameters. The relationship between the surface morphologies and condensate self-removal capability is investigated, and a guideline for laser processing parameterization for fabricating optimal anti-frosting SHSs is established. After 120 min of the frosting test, the optimized surface exhibits less than 70% frost coverage because the remarkably enhanced condensate self-removal capability reduces the water accumulation amount and frost propagation speed (<1 μm/s). Additionally, the material adaptability of the proposed technique is validated by extending this methodology to other metals and metal alloys. This study provides valuable and instructive insights into the design and optimization of metallic anti-frosting SHSs by ultrafast laser processing.

Improvements in Brazed-Joint Properties of Silicon Nitride and Titanium Alloys Using Laser-Induced Microscale Rice Leaf Structures

Si₃N₄ ceramics with a microscale rice leaf structure (MRLS) and titanium alloy were connected via brazing, and the influence of the surface microstructure on the ceramic connection was analyzed. MRLS fabrication is an efficient and high-degree-of-freedom method that can be used to change a material's surface morphology and wettability. The MRLS was obtained at a laser power of 110 W, with line spacings of 100 and 50 μm. The laser-treated surface included nanoparticles and micro particles, exhibiting a coral-like structure after agglomeration. When the MRLS was used to braze the titanium alloy, no defects were observed at the brazing interface, and the formation was excellent. Throughout the brazed joint, the MRLS remained intact and formed a strong metallurgical bond with the brazing filler metal. A finite element analysis was performed to study the cross-sectional morphology after joint fracture; from the load-time curve, it was found that the MRLS on the surface not only helped improve the mechanical occlusion and brazing area at the interface, but also helped generate compressive stress on the Si₃N₄ side. Crack propagation was hindered, thereby increasing the joint strength.

[Prediction of clinical outcomes of patients with surplus cleavage-stage embryos for blastocyst culture after D3 embryo transfer]

Objective: To find the best strategy of embryo transfer, so as to provide theoretical basis for improving the clinical outcomes of in vitro fertilization-Embryo transfer (IVF-ET), we investigate the blastocyst culture of surplus cleavage-stage embryos after D3 embryo transfer and the prediction of clinical outcomes with or without blastocyst formation. Methods: A retrospective study was conducted on 3 568 patients who underwent IVF-ET in the Reproductive Medicine Center of the First Affiliated Hospital of Zhengzhou University from January 2016 to May 2018, whotransplanted two embryos in D3 with blastocyst culture of surplus cleavage-stage embryos, according to their age, they were divided into three groups: <35 years old group, 35-38 years old group, and>38 years old group.And according to the presence or absence of blastocyst formation, they were also divided into two subgroups: blastocyst formation group and non-blastocyst formation group. The embryo development and clinical outcomes in each group were compared. Results: (1) Comparisons of the embryo development in the three age groups with the first cycle. The total fertilization rate, cleavage rate and high quality embryo rate of the blastocyst formation group in the three groups were higher than those in the non-blastocyst formation group, P<0.05; In<35 years old group, the embryo utilization rate (75.0% vs 70.6%), pregnancy rate (74.9% vs 70.3%), planting rate (53.6% vs 48.6%), delivery rate (66.7% vs 61.1%) and live birth rate (66.5% vs 61.0%) of the blastocyst formation group were higher than those in the non-blastocyst formation group, P<0.05. (2) Comparisons of embryo development in the three age groups with multiple cycles (≥2 cycles). In<35 years old group, the total fertilization rate (75.0% vs 70.6%),delivery rate (62.7% vs 43.8%) and live birth rate (62.7% vs 43.8%) of the blastocyst formation group were significantly higher than those in the non-blastocyst formation group, P<0.05; In>38 years old group, the pregnancy rate (56.3% vs 25.8%), implantation rate (34.4% vs 14.5%), delivery rate (43.8% vs 11.3%), live birth rate (43.8% vs 11.3%) of the blastocyst formation group were higher than those in the non-blastocyst formation group, P<0.05. Conclusions: The results of blastocyst culture in different groups can predict the outcomes of embryo transfer in D3. For patients<35 years old with the first cycle, the clinical outcomes of the blastocyst formation group after D3 embryo transfer is better than that of the non-blastocyst formation group. For Patients with multiple cycles (≥2 cycles),the clinical outcomes of the embryo formation group is superior to that of the non-blastocyst formation group<35 years old or>38 years old.

Effect of Dietary Non-phytate Phosphorus Levels on the Diversity and Structure of Cecal Microbiota in Meat Duck from 1 to 21 d of age

The study was conducted to distinguish the effect of dietary non-phytate phosphorus (NPP) levels on the community diversity and structure of the cecal microbiota in meat duck based on 16S rDNA high-throughput sequencing. In total, 525 1-d-old ducklings were fed diets (105 ducklings, 7 pens of 15 ducklings, on each diet) containing five levels of NPP (0.22, 0.34, 0.40, 0.46, and 0.58%) for 21 days. The results showed that dietary NPP levels linearly and quadratically increased (P < 0.05) 21 d body weight, 1 to 21 d feed intake and NPP intake, and contrarily, linearly decreased (P < 0.05) β-diversity of cecal microbial population in ducks. ß-diversity analyses showed that microbiota clustering based on dietary NPP levels occured, with 0.22% NPP groups distinctly different from the 0.46% and 0.58% NPP group samples. Moreover, dietary NPP levels could change the relative abundance of the phylum Proteobacteria (linear, P < 0.05), genera Eubacterium coprostanoligenes (quadratic, P < 0.05), Ruminococcaceae UCG-014 (quadratic, P < 0.05) and Subdoligrannulum (linear, P < 0.05), and Lachnospiraceae family (quadratic, P < 0.05) in cecal microbiota of ducks. Increasing the dietary NPP level influenced the cecal microbiota and positively affected the growth of meat ducks.

[Long-term efficacy of lactulose in patients with subclinical hepatic encephalopathy]

OBJECTIVE

To observe the long-term clinical efficacy of lactulose in patients with subclinical hepatic encephalopathy (SHE) and the natural history of this disease.

METHODS

Patients with SHE diagnosed with psychometric tests (number connection test and digit symbol test) were randomly allocated to control group (Cg), short-term (Stg) and long-term treatment group (Ltg), respectively. Lactulose (15 - 90 ml/day) was orally given to 21 patients in Stg for 8 weeks, and 22 in Ltg for 24 weeks.The drug was not given to 21 patients in Cg. Psychometric test, somatosensory evoked potentials (SEP) and venous blood ammonia concentration (BA) were investigated before and after treatment at 8 week intervals for 6 months of follow-up.

RESULTS

In Ltg, psychometric tests were significantly improved, BA was lowered and N(50) peak latency in SEP was not prolonged as compared with those in Cg, in which psychometric tests and N(50) peak latency gradually worsened during the follow-up. After 8 weeks of treatment, psychometric tests, BA and N(50) peak latency were significantly improved in Stg, but at week 24 they were deteriorated after cessation of treatment. The development of clinical hepatic encephalopathy was more frequent in Cg (40%) and Stg (30%) than in Ltg (5%). One patient each was not followed up after week 24 in Cg and Stg, respectively and 2 patients in Ltg stopped lactulose because of severe diarrhea.

CONCLUSIONS

In patients with SHE, long-term treatment with lactulose could lower BA, improve psychometric tests, prevent SEP from getting worse, and eventually cut down the occurrence rate of clinical hepatic encephalopathy.