Improved deep learning for automatic localisation and segmentation of rectal cancer on T2-weighted MRI.

INTRODUCTION: The automatic segmentation approaches of rectal cancer from magnetic resonance imaging (MRI) are very valuable to relieve physicians from heavy workloads and enhance working efficiency. This study aimed to compare the segmentation accuracy of a proposed model with the other three models and the inter-observer consistency. METHODS: A total of 65 patients with rectal cancer who underwent MRI examination were enrolled in our cohort and were randomly divided into a training cohort (n = 45) and a validation cohort (n = 20). Two experienced radiologists independently segmented rectal cancer lesions. A novel segmentation model (AttSEResUNet) was trained on T2WI based on ResUNet and attention mechanisms. The segmentation performance of the AttSEResUNet, U-Net, ResUNet and U-Net with Attention Gate (AttUNet) was compared, using Dice similarity coefficient (DSC), Hausdorff distance (HD), mean distance to agreement (MDA) and Jaccard index. The segmentation variability of automatic segmentation models and inter-observer was also evaluated. RESULTS: The AttSEResUNet with post-processing showed perfect lesion recognition rate (100%) and false recognition rate (0), and its evaluation metrics outperformed other three models for two independent readers (observer 1: DSC = 0.839 ± 0.112, HD = 9.55 ± 6.68, MDA = 0.556 ± 0.722, Jaccard index = 0.736 ± 0.150; observer 2: DSC = 0.856 ± 0.099, HD = 11.0 ± 10.1, MDA = 0.789 ± 1.07, Jaccard index = 0.673 ± 0.130). The segmentation performance of AttSEResUNet was comparable and similar to manual variability (DSC = 0.857 ± 0.115, HD = 10.0 ± 10.0, MDA = 0.704 ± 1.17, Jaccard index = 0.666 ± 0.139). CONCLUSION: Comparing with other three models, the proposed AttSEResUNet model was demonstrated as a more accurate model for contouring the rectal tumours in axial T2WI images, whose variability was similar to that of inter-observer.

Feasibility of Omitting Sentinel Lymph Node Biopsy in an Under-screened Cohort of Breast Cancer Patients With a Premastectomy Diagnosis of Ductal Carcinoma In Situ.

BACKGROUND: Nodal involvement in ductal carcinoma in situ (DCIS) is rare. In patients with DCIS diagnosis prior to mastectomy, a sentinel lymph node biopsy (SLNB) is usually performed during mastectomy, to avoid the risk of reoperation and the non-identification of SLN subsequently, should there be an upgrade to invasive cancer. We aimed to study the feasibility of omitting SLNB in an under-screened cohort, with mostly symptomatic patients and DCIS diagnosis before mastectomy, by determining the upgrade rate to invasive cancer/ DCIS microinvasion (DCISM) and its associated risk factors. METHODS: Patients with pure DCIS diagnosis premastectomy were reviewed retrospectively. Patients with known DCISM or invasive cancer before mastectomy and bilateral cancers were excluded. Patients' demographics, radiological and pathological data premastectomy were analyzed. RESULTS: A total of 189 patients were included. The mean age was 53.8 (range: 29-85) years old. About 64.4% presented with symptoms. 36.0% and 15.3% upgraded to invasive cancer and DCISM on mastectomy respectively. Palpable tumor (P = .0036), large size on ultrasound (P = .0283), tumor seen on mammogram and ultrasound (P = .0082), ultrasound-guided biopsy (P < .0001), high-grade DCIS on biopsy (P = .0350) and no open biopsy/lumpectomy before mastectomy (P < .0001) were associated with the upgrade, with the latter factor remaining significant after multivariable analysis. Nodal involvement was 8.47% and was associated with invasive cancer (P < .0001). CONCLUSION: In a cohort who had DCIS diagnosis before mastectomy and were mostly symptomatic, the upgrade rate was 51.3%. Despite the high upgrade rate, nodal involvement remained comparable. Risk factors could select patients for omission of upfront SLNB, with a delayed SLNB planned if needed.

Accurate spectrogram restoration algorithm for an echelle spectrometer based on adaptive parameters.

The echelle spectrometer is a high-resolution spectrometer that can realize transient direct readings of a full spectrum. To improve the accuracy of the spectrogram restoration model in calibration, multiple-integral time fusion, and an improved adaptive-threshold centroid algorithm are used to overcome noise and improve the accuracy of calculating the light spot position. A seven-parameter pyramid-traversal method is proposed to optimize the parameters of the spectrogram restoration model. The deviation of the spectrogram model is significantly reduced after the parameters are optimized, and the deviation curve fluctuation becomes mild, which greatly improves the model's accuracy after curve fitting.The test results show that the accuracy of the spot position determination algorithm proposed in this paper is 0.1 pixels. In addition to this, the accuracy of the spectral restoration model is controlled within 0.3 pixels in a short-wave stage and 0.7 pixels in a long-wave stage. Compared with the traditional algorithm, the accuracy of spectrogram restoration is more than two times, and the spectral calibration time is less than 45 min.

Portfolio use in postgraduate medical education: a systematic scoping review.

BACKGROUND: Portfolios are increasingly commonplace in postgraduate medical education. However, poor understanding of and variations in their content, quality, and structure have hindered their use across different settings, thus dampening their efficacy. METHODS: This systematic scoping review on portfolios in postgraduate medical education utilized Krishna's Systematic Evidence Based Approach (SEBA). Braun and Clarke's thematic analysis and Hsieh and Shannon's directed content analysis were independently used to evaluate the data. RESULTS: In total, 12 313 abstracts were obtained, and 76 full-text articles included. Six key themes/categories were identified: (i) portfolio definitions and functions, (ii) platforms, (iii) design, (iv) implementation, (v) use in assessments, and (vi) evaluations of their usage. CONCLUSIONS: Portfolios allow for better appreciation and assessments of knowledge, skills, and attitudes in time-, learner-, and context-specific competencies through the establishment of smaller micro-competencies and micro-credentialling. Organized into three broad stages-development, implementation, and improvement-a six-step framework for optimizing and instituting portfolios in postgraduate medical education is offered.

Dynamic experiments of acid mine drainage with Rhodopseudomonas spheroides activated lignite immobilized sulfate-reducing bacteria particles treatment.

Aiming at the problem that the treatment of acid mine drainage (AMD) by sulfate-reducing bacteria (SRB) biological method is susceptible to pH, metal ions, sulfate and carbon source. Lignite immobilized SRB particles (SRB-LP) and Rhodopseudomonas spheroides (R. spheroides) activated lignite immobilized SRB particles (R-SRB-LP) were prepared using microbial immobilization technology with SRB, R. spheroides and lignite as the main substrates. The dynamic experimental columns 1# and 2# were constructed with SRB-LP and R-SRB-LP as fillers, respectively, to investigate the dynamic repair effect of SRB-LP and R-SRB-LP on AMD. The mechanism of AMD treated with R-L-SRB particles was analyzed by scanning electron microscopy (SEM), fourier transform infrared (FTIR) spectrometer and low-temperature nitrogen adsorption. The result showed that the combination of R. spheroides and lignite could continuously provide carbon source for SRB, so that the highest removal rates of SO42-, Cu2+ and Zn2+ in AMD by R-SRB-LP were 93.97%, 98.52% and 94.42%, respectively, and the highest pH value was 7.60. The dynamic repair effect of R-SRB-LP on AMD was significantly better than that of SRB-LP. The characterization results indicated that after R-SRB-LP reaction, the functional groups of -OH and large benzene ring structure in lignite were broken, the lignite structure was destroyed, and the specific surface area was 1.58 times larger than before reaction. It illustrated that R. spheroides provided carbon source for SRB by degrading lignite. The strong SRB activity in R-SRB-LP, SRB can co-treat AMD with lignite, so that the dynamic treatment effect of R-SRB-LP on AMD is significantly better than that of SRB-LP.

Fuzhuan brick tea polysaccharides serve as a promising candidate for remodeling the gut microbiota from colitis subjects in vitro: Fermentation characteristic and anti-inflammatory activity.

The purified fraction 3 of polysaccharides from Fuzhuan brick tea (FBTPS-3) could attenuate the colitis and modulate the gut microbiota. However, the relationship between anti-inflammatory effect of FBTPS-3 and the gut microbiota is still unknown. Thus, the anaerobic fermentation in vitro was used to investigate the potential mechanism. FBTPS-3 could be utilized and degraded by gut microbiota from inflammatory bowel disease (IBD) subjects. Furthermore, FBTPS-3 could modulate the composition and structure of IBD gut microbiota toward to that of healthy group. FBTPS-3 showed a superior modulated effect on IBD gut microbiota by increasing Bacteroides and decreasing Escherichia/Shigella. Furthermore, the fermentation solution rather than FBTPS-3 itself showed anti-inflammatory effects on lipopolysaccharide-treated RAW264.7 macrophages, which might be due to the metabolites such as short-chain fatty acids (SCFAs). Thus, FBTPS-3 can be expected as novel prebiotics for treatment of IBD via modulating gut microbiota, and promoting the production of SCFAs.

Effect of Long-Term Thermal Aging on Microstructure Evolution and Creep Deformation Behavior of a Novel 11Cr-3W-3Co Martensite Ferritic Steel.

This paper focused on the microstructure evolution under different thermal aging times at 650 °C and its effect on creep behavior in 11Cr-3W-3Co heat-resistant steel. After short-term thermal aging at 650 °C (>750 h), a Laves phase was found in the regions adjacent to the PAG boundaries, martensitic lath boundaries, and M23C6 carbides, and gradually swallowed adjacent M23C6 carbides with the aging time increased. Higher contents of Si and P are good promoters of the nucleation of the Laves phase during long-term aging. In addition, the coarsening behavior of the Laves phase, M23C6, and MX were investigated. As the aging time increases, the coarsening behavior among precipitated phases in the above-mentioned example exhibits remarkable variability, which is discussed in detail in this paper, and the evolution of the subgrain size was also analyzed in detail. The increasing rate of subgrain size is, in general, consistent with that of the M23C6 carbide size. The evolution of dislocation density in different aging times shows an obvious difference, and the decreasing rate of dislocation density is significantly affected by the precipitated phase after long-term aging time. The creep performance of the material decreases significantly as the aging time increases, which is closely related to the coarsening of the precipitates such as M23C6 carbides and subgrain during long-term aging.

Effect of Long-Term Aging on the Microstructural Evolution in a P91 Steel.

The precipitation and growth mechanism of the Laves phase and the coarsening behaviors of Laves phase, M23C6 and MX carbonitrides have been emphatically investigated in P91 steel at 625 °C under different aging conditions. After long-term aging at 625 °C (>1500 h), it was observed that the Laves phase grew rapidly in the region near the M23C6 carbide once precipitated, and further gradually completed the engulfment process until the M23C6 carbide particles disappeared. Furthermore, a new crystallographic orientation relationship between M23C6 carbides and Laves phase has been observed at 625 °C for 5000 h, which is {0001}Laves∥{111}M23C6, <112¯1>Laves∥ <011>M23C6. The coarsening behaviors of Laves phase, M23C6 carbides and MX carbonitrides have been emphatically investigated, conforming to the existing ripening model of multicomponent alloys. The coarsening rates for the Laves phase, M23C6 and MX have values of ~32.2 (≥5000 h), 5.3 and 0.6 nm/h1/3, respectively.

Preparation of biologically activated lignite immobilized SRB particles and their AMD treatment characteristics.

In response to the insufficient supply of carbon sources and the toxicity of heavy metal ions when using sulfate reducing bacteria (SRB) to treat acid mine wastewater (AMD), the immobilized particles are prepared with Rhodopseudomonas, SRB and lignite as the main raw materials. And based on single factor test and orthogonal test to determine the optimal ratio of biologically activated lignite fixed SRB particles. The adsorption characteristics of immobilized particles were studied under the optimal ratio, and the reaction kinetics and adsorption capacity of SRB particles immobilized on biologically activated lignite to different ions were analyzed. The results show that: lignite not only has good adsorption performance, but also can be used as the carbon source of SRB after being degraded by Rhodopseudomonas, solving the problems of low removal efficiency of SRB treatment of AMD and insufficient carbon source supply. When the dosage of lignite (particle size is 200 mesh), Rhodopseudomonas, and SRB are 3%, 10%, and 10% mesh, the prepared biologically activated lignite-immobilized SRB particles have the best effect on AMD treatment. The removal rates of SO42-, Zn2+, and Cu2+ were 83.21%, 99.59%, and 99.93%, respectively, the pH was increased to 7.43, the COD release was 523 mg/L, and the ORP value was - 134 mV. The reduction process of SO42- by the biologically activated lignite-immobilized SRB particles conforms to the pseudo-first-order kinetics, and the adsorption of Zn2+ is more in line with the Freundlich isotherm adsorption equation and the pseudo-second-order kinetic model. And it does not spread in a single form, both internal and external diffusion occur. SEM, FT-IR, and BET analysis of biologically activated lignite immobilized SRB particles showed that the pore structure is developed, has a large number of adsorption sites, and some activated groups participate in the reaction. The adsorption process of Zn2+ and Cu2+ in AMD meets the multi-layer adsorption theory.

A case of fibroadenoma with lobular carcinoma in situ and microinvasion in a young woman.

Fibroadenomas are benign breast tumors with a rare incidence of malignant transformation. Carcinoma arising within fibroadenomas typically occurs in women above the age of 40. We present a case of a young patient with microinvasive carcinoma arising within a biopsy-proven fibroadenoma, highlighting the possibility of carcinoma arising within fibroadenomas in young patients and the importance of vigilant surveillance even after a benign biopsy. In younger patients, new suspicious changes in benign lesions should be investigated. If prior core needle biopsy was performed, excision biopsy should be considered as the malignancy may be small and may be missed on needle biopsy.

Research on spectral reconstruction algorithm for snapshot microlens array micro-hyperspectral imaging system.

Snapshot microlens array microscopic hyperspectral imaging systems do not require a scanning process and obtain (x,y,λ) three-dimensional data cubes in one shot. Currently, the three-dimensional spectra image data are interleaved on a charge-coupled device detector, which increases subsequent data processing difficulty. The optical design software cannot simulate actual engineering installation and adjustment results accurately and the tracking results cannot guide precise rapid online calibration of the snapshot microlens array microscopic hyperspectral imaging system. To solve these problems, we propose an accurate spectral image reconstruction model based on optical tracing, derive spatial dispersion equations for the prisms and gratings, establish an algorithm model for the correspondence between the microlens array's surface dispersion spectral distribution and its imaging position, and propose a three-dimensional spectral image reconstruction algorithm. Experimental results show that this algorithm's actual spectral calibration error is better than 0.2 nm. This meets the image processing requirements of snapshot microlens array microscopic hyperspectral systems.

Microlens array snapshot hyperspectral microscopy system for the biomedical domain.

We propose a microlens array-type snapshot hyperspectral microscope system that can provide spatial spectrum sampling according to detector frame rates for the biomedical domain. The system uses a shared optical path design. One path is used to perform direct microscopic imaging with high spatial resolution, while the other is used to collect microscopic images through a microlens array; the images are then spatially cut and reimaged such that they are spaced simultaneously by the prism-grating type hyperspectral imager's dispersion. Rapid acquisition of a three-dimensional data cube measuring 28×14×180 (x×y×λ) can be performed at the detector's frame rate. The system has a spatial resolution of 2.5 µm and can achieve 180-channel sampling of a 100 nm spectrum in the 400-800 nm spectral range with spectral resolution of approximately 0.56 nm. Spectral imaging results from biological samples show that the microlens array-type snapshot hyperspectral microscope system may potentially be applied in real-time biological spectral imaging.

Purified fraction of polysaccharides from Fuzhuan brick tea modulates the composition and metabolism of gut microbiota in anaerobic fermentation in vitro.

One purified fraction from crude Fuzhuan brick tea polysaccharides (FBTPS), FBTPS-3, was obtained through column chromatography of DEAE Sepharose Fast Flow. The chemical properties and probiotic effects of FBTPS-3 were evaluated by fermentation in vitro. Moreover, the effects of FBTPS-3 on the function and metabolic pathway of gut microbiota were investigated by metagenomic sequencing. The results showed that FBTPS-3 was an heteropolysaccharide with molecular weight of 741 kDa, which was mainly composed of Man, Rha, GalA, Gal and Ara in molar ratio of 8.7:15.5:42.2:19.7:13.9. The contents of carbohydrates and uronic acid in FBTPS-3 were 44.78 ±â€¯2.85% and 40.4 ±â€¯2.11%, respectively. After fermentation, the molecular weight of FBTPS-3 and content of carbohydrates were significantly decreased, indicating that FBTPS-3 could be utilized by gut microbiota. Furthermore, the relative abundances of Bacteroides, Megasphaera and Prevotella were significantly increased by FBTPS-3. FBTPS-3 also significantly promoted the production of acetic, propionic and n-butyric acids. Based on the metagenomic sequencing, it was found that FBTPS-3 significantly enriched the metabolic pathway of starch and sucrose. All the results suggest that FBTPS-3 is expected to be developed as functional ingredients or foods to improve the host health through regulating the gut microbiota and physiological metabolic functions.

Dispersion of Poly(urea-formaldehyde)-Based Microcapsules for Self-Healing and Anticorrosion Applications.

An effective dispersant, oleyl phosphate (OP), for the dispersion of poly(urea-formaldehyde)-based microcapsules in a typical epoxy coating material is proposed. Based on electron microscopy observations and rheological and mechanical characterizations, it is observed that the addition of merely 0.5 wt % of OP is sufficient to obtain good dispersion of the microcapsules in the epoxy. In the self-healing and anticorrosion experiments, a microcapsule content of at least 15 wt % is required to efficiently restore the epoxy matrix and provide corrosion protection to underlying low-carbon steel when the particles are not dispersed; however, the amount of microcapsules required to obtain good self-healing and anticorrosion efficiencies can be greatly reduced to only 5 wt % when the microcapsules are dispersed by OP.

Evaluation of chemical property, cytotoxicity and antioxidant activity in vitro and in vivo of polysaccharides from Fuzhuan brick teas.

Fuzhuan brick tea (FBT) possesses various health-promoting functions. However, the available information regarding biological activity of polysaccharides from FBT (FBTPS) is still limited. In this work, the chemical property, cytotoxicity and antioxidant activity in vitro and in vivo of FBTPS were evaluated. It was found that FBTPSs were typical acidic heteropolysaccharides mainly composed of Man, Rha, GalA, Glc, Gal and Ara with little molar content of Rib and GlcA. FBTPS showed little toxicity to human hepatic epithelial (L-02) cell. FBTPS exhibited antioxidant activities, including limited scavenging activity on DPPH free radicals (ranged from 54.3 ±â€¯1.9 to 67.8 ±â€¯2.5%), noticeable scavenging activity on superoxide radicals (over 85%), superior scavenging activity on ABTS radicals (near 100%), and protective effect on H2O2-induced oxidative injury in rat pheochromocytoma line 12 (PC12) cell. Moreover, FBTPS showed significant amelioration of high-fat diet-induced oxidative injury in mice. The results suggest that FBTPS, as natural safe antioxidants, may have potential application in functional foods.

Preparation and characterization of gelatin-hydroxyapatite composite microspheres for hard tissue repair.

Gelatin-hydroxyapatite composite microspheres composed of 21% gelatin (G) and 79% hydroxyapatite (HA) with uniform morphology and controllable size were synthesized from a mixed solution of Ca(NO3)2, NH4H2PO4 and gelatin by a wet-chemical method. Material analyses such as X-ray diffraction (XRD), scanning/transmission electron microscopy examination (SEM/TEM) and inductively coupled plasma-mass spectroscopy (ICP-MS) were used to characterize G-HA microspheres by analyzing their crystalline phase, microstructure, morphology and composition. HA crystals precipitate along G fibers to form nano-rods with diameters of 6-10nm and tangle into porous microspheres after blending. The cell culture indicates that G-HA composite microspheres without any toxicity could enhance the proliferation and differentiation of osteoblast-like cells. In a rat calvarial defect model, G-HA bioactive scaffolds were compared with fibrin glue (F) and Osteoset® Bone Graft Substitute (OS) for their capacity of regenerating bone. Four weeks post-implantation, new bone, mineralization, and expanded blood vessel area were found in G-HA scaffolds, indicating greater osteoconductivity and bioactivity than F and OS.