Common feature learning for brain tumor MRI synthesis by context-aware generative adversarial network.

Multi-modal structural Magnetic Resonance Image (MRI) provides complementary information and has been used widely for diagnosis and treatment planning of gliomas. While machine learning is popularly adopted to process and analyze MRI images, most existing tools are based on complete sets of multi-modality images that are costly and sometimes impossible to acquire in real clinical scenarios. In this work, we address the challenge of multi-modality glioma MRI synthesis often with incomplete MRI modalities. We propose 3D Common-feature learning-based Context-aware Generative Adversarial Network (CoCa-GAN) for this purpose. In particular, our proposed CoCa-GAN method adopts the encoder-decoder architecture to map the input modalities into a common feature space by the encoder, from which (1) the missing target modality(-ies) can be synthesized by the decoder, and also (2) the jointly conducted segmentation of the gliomas can help the synthesis task to better focus on the tumor regions. The synthesis and segmentation tasks share the same common feature space, while multi-task learning boosts both their performances. In particular, for the encoder to derive the common feature space, we propose and validate two different models, i.e., (1) early-fusion CoCa-GAN (eCoCa-GAN) and (2) intermediate-fusion CoCa-GAN (iCoCa-GAN). The experimental results demonstrate that the proposed iCoCa-GAN outperforms other state-of-the-art methods in synthesis of missing image modalities. Moreover, our method is flexible to handle the arbitrary combination of input/output image modalities, which makes it feasible to process brain tumor MRI data in real clinical circumstances.

Improvement of morpho-physiological, ultrastructural and nutritional profiles in wheat seedlings through astaxanthin nanoparticles alleviating the cadmium toxicity.

Heavy metal accumulation in arable lands and water bodies has become one of the serious global issues among multitude of food security challenges. In particular, cadmium (Cd) concentration has been increasing substantially in the environment that negatively affects the growth and yield of important agricultural crops, especially wheat (Triticum aestivum L.). No doubt, nanotechnology is a revolutionary science but the comprehension of nanoparticle-plants interaction and its potential alleviatory role against metal stress is still elusive. Here, we investigated the mechanistic role of astaxanthin nanoparticles (AstNPs) in Cd stress amelioration and their interaction with wheat under Cd-spiked conditions. The AstNPs fabrication was confirmed through ultraviolet visible spectroscopy, where the particles showed characteristic peak at 423 nm. However, Fourier transform infrared, X-ray diffraction, scanning electron microscopy and transmission electron microscopy analyses confirmed the presence of stabilized spherical-shaped nanocrystals of AstNPs within the size range of 12.03-30.37 nm. The hydroponic application of AstNPs (100 mg L-1) to Cd-affected wheat plants increased shoot height (59%), shoot dry weight (31%), nitrogen concentration (42%), and phosphorus concentration (26%) as compared to non-treated Cd affected seedlings. Moreover, AstNPs-treated plants showed reduction in acropetal Cd translocation (29%) in contrast to plants treated with Cd only. Under Cd-spiked conditions, AstNPs-treated plants displayed an improved nutrient profile (P, N, K+ and Ca2+) with a relative decrease in Na+ content in comparison with non-treated plants. Interestingly, it was found that AstNPs restricted the translocation of Cd to aerial plant parts by negatively regulating Cd transporter genes (TaHMA2 and TaHMA3), and relieved plants from oxidative burst by activating antioxidant machinery via triggering expressions of TaSOD and TaPOD genes. Consequently, it was observed that the application of AstNPs helped in maintaining the nutrient acquisition and ionic homeostasis in Cd-affected wheat plants, which subsequently improved the physiochemical profiles of plants under Cd-stress. This study suggests that AstNPs plausibly serve as stress stabilizers for plants under heavy metal-polluted environment.

Analysis of 85 Cases of Minimal Media Lower Hemisternotomy for Congenital Cardiac Surgery Under Cardiopulmonary Bypass in Infants.

OBJECTIVE: To investigate the feasibility and effect of minimal media lower hemisternotomy for cardiac surgery under cardiopulmonary bypass (CPB) in infant congenital heart disease. METHODS: In our hospital from May 2019 to October 2019, 170 infants with congenital heart disease underwent surgical treatment (median age 6.6 months; weight 6.0 kg). They were divided into 2 groups: those with conventional chest median incision and those with minimal sternotomy. Minimal lower hemisternotomy began from the third intercostal level and ended 0.5 cm above the xiphoid, just enough to insert a small sternal distractor. RESULTS: There was no significant difference between the 2 groups in CPB time. The operation time of small incision group was slightly longer (P < .05). There was no difference in prognosis between the 2 groups, but the wound length of the small incision group was significantly reduced (4.0 ± 0.5 versus 7.8 ± 0.8 cm, P < .05). Time of intensive care unit and hospital stay was shorter among hemisternotomy patients at a statistically significant level (P < .05). CONCLUSION: Minimal media lower hemisternotomy with the basic advantages of the sternal incision can expose the various parts of the heart, which meets most cardiac exploration and surgical operation needs, and the incision may still be extended if necessary. Lower hemisternotomy appears to be a safe, effective, and versatile alternative for many surgical interventions in infants with congenital heart disease.

Modulation of Key Physio-Biochemical and Ultrastructural Attributes after Synergistic Application of Zinc and Silicon on Rice under Cadmium Stress.

Excessive industrialization and the usage of pesticides plague the farming soils with heavy metals, reducing the quality of arable land. Assessing phytoavailability of cadmium (Cd) from growth medium to plant system is crucial and necessitates precise and timely monitoring of Cd to ensure food safety. Zinc (Zn) and silicon (Si) have singularly demonstrated the potential to ameliorate Cd toxicity and are important for agricultural production, human health, and environment in general. However, Zn-Si interaction on Cd toxicity alleviation, their effects and underlying mechanisms are still fragmentarily understood. Seven treatments were devised besides control to evaluate the single and combined effects of Zn and Si on the physio-biochemical attributes and ultrastructural fingerprints of Cd-treated rice genotypes, i.e., Cd tolerant "Xiushui-110" and Cd sensitive "HIPJ-1". Supplementation of both Zn and Si promoted plant biomass, photosynthetic parameters, ionic balance, and improved chloroplast ultrastructure with minimized Cd uptake and malondialdehyde (MDA) content due to the activation of antioxidant enzymes in Cd stressed plants. The combined effects of 10 µM Zn and 15 µM Si on 15 µM Cd displayed a greater reduction in Cd uptake and root-leaf MDA content, while enhancing photosynthetic activity, superoxide dismutase (SOD) activity and root-leaf ultrastructure particularly in HIPJ-1, whilst Xiushui-110 had an overall higher leaf catalase (CAT) activity and a higher root length and shoot height was observed in both genotypes compared to the Cd 15 µM treatment. Alone and combined Zn and Si alleviation treatments reduced Cd translocation from the root to the stem for HIPJ-1 but not for Xiushui-110. Our results confer that Zn and Si singularly and in combination are highly effective in reducing tissue Cd content in both genotypes, the mechanism behind which could be the dilution effect of Cd due to improved biomass and competitive nature of Zn and Si, culminating in Cd toxicity alleviation. This study could open new avenues for characterizing interactive effects of simultaneously augmented nutrients in crops and provide a bench mark for crop scientists and farmers to improve Cd tolerance in rice.

SLIR: Synthesis, localization, inpainting, and registration for image-guided thermal ablation of liver tumors.

Thermal ablation is a minimally invasive procedure for treating small or unresectable tumors. Although CT is widely used for guiding ablation procedures, yet the contrast of tumors against normal soft tissues is often poor in CT scans, aggravating the accurate thermal ablation. In this paper, we propose a fast MR-CT image registration method to overlay pre-procedural MR (pMR) and pre-procedural CT (pCT) images onto an intra-procedural CT (iCT) image to guide the thermal ablation of liver tumors. At the pre-procedural stage, the Cycle-GAN model with mutual information constraint is employed to generate the synthesized CT (sCT) image from the input pMR. Then, pMR-pCT image registration is carried out via traditional mono-modal sCT-pCT image registration. At the intra-procedural stage, the region of the probe and its artifacts are automatically localized and inpainted in the iCT image. Then, an unsupervised registration network (UR-Net) is used to efficiently align the pCT with the inpainted iCT (inpCT) image. The final transform from pMR to iCT is obtained by concatenating the two estimated transforms, i.e., (i) from pMR image space to pCT image space (via sCT) and (ii) from pCT image space to iCT image space (via inpCT). The proposed method has been evaluated over a real clinical dataset and compared with state-of-the-art methods. Experimental results confirm that the proposed method achieves high registration accuracy with fast computation speed.

Different structural remodelling in atrial fibrillation with different types of mitral valvular diseases.

AIMS: The aim of this study was to determine the relationship between atrial structural remodelling and atrial fibrillation (AF) for different types of mitral valvular diseases (MVDs). METHODS AND RESULTS: Left atrial appendages tissue samples were obtained from 24 patients with MVDs undergoing mitral valve replacement surgery. Masson's trichrome staining and immunohistochemical staining were performed to assess the extent of the fibrosis. Ultrastructural changes in left atrial appendages were examined by electron microscope. The degree of fibrosis showed significant increases in patients with AF compared with patients with sinus rhythm (SR) (P = 0.023). The collagen volume fraction (CVF) of fibrosis significantly increased in mitral stenosis and atrial fibrillation (MS-AF) compared with the mitral regurgitation and atrial fibrillation (MR-AF) group (P = 0.043). Collagen Type I levels were significantly increased in AF patients with mitral stenosis compared with AF patients with mitral regurgitation (P = 0.043). Different CVF of Matrix metalloproteinases-2 was present between the MS-SR group and the MS-AF group (P = 0.001). Electron microscopy revealed normally structured sarcomeres with a predominance of loosely packed cardiomyocytes in samples from patients with SR. Fibrotic bands, which tended to separate individual cardiomyocytes, were apparent in samples from patients with AF. CONCLUSION: Atrial structural remodelling is associated with AF patients with MVDs. Different heart rhythm statuses with different types of MVDs are associated with variable atrial structural remodelling. Different atrial structural remodelling is a mechanism that may contribute to the increased risk of AF with MVDs.

[Impact of tricuspid annuloplasty on changes of right atrioventricular diameter and annulus in patients with mitral valve replacement].

OBJECTIVE: To observe changes of right atrioventricular diameter and annulus after mitral valve replacement (MVR) in patients with and without tricuspid annuloplasty. METHODS: A total of 112 patients who underwent MVR surgery from April 2005 to December 2006 were recruited in this study. The patients were divided into two groups. Those with maximal tricuspid annulus diameter/body surface area > or = 21 mm/m2 were given tricuspid annuloplasty (TAPG, n=56). Otherwise, no tricuspid annuloplasty were performed (NTAPG, n=56). All of the patients were followed up regularly. The echocardiography were reviewed two years after the surgery. RESULTS: An average of (25.04 +/- 5.04) months had passed when the echocardiography were reviewed. The two groups had no differences in age, gender, body surface areas and cardiac functions (P>0.05). The TVPG group had more patients with atrial fibrillation than the NTVPG group (P<0.05). In the patients in the TVPG group, the right atrioventricular diameter, and maximal and minimal tricuspid annulus diameter were significantly narrowed after the operations (P<0.05). The percent shorting of tricuspid valve annulus did not change significantly (P> 0.05). The constituent ratio of TR was significantly reduced (P<0.05). However, in the patients in the NTVPG group, the right atrioventricular diameter did not change significantly (P>0.05). The maximal and minimal tricuspid annulus diameter increased (P<0.05). The percent shorting of tricuspid valve annulus did not change significantly (P>0.05). Though the constituent ratio of TR had no significant changes, 5 (13.5%) patients developed moderate or serious TR two years after the operations. CONCLUSION: Tricuspid annuloplasty (TAP) has benefits for the patients with enlarged right atrioventricular and tricuspid annulus. For those patients without enlarged right atrioventricular and tricuspid, their tricuspid valve conditions should also be carefully assessed. Because as time lapse, these patients may also develop TR.