Enhanced toughness and strength of 3D printed carbide-oxide composite for biomedical applications.

Natural materials derived/extracted Ceramics is an excellent material for developing ceramic-based orthopedic implants. Recently, we have demonstrated an easily scalable, energy-efficient green method to extract ceramic particles from bio-waste i.e. chicken bone. Though the chicken bone extract (CBE) has good biocompatibility, it lacks good mechanical properties in the 3D printed condition as that of human bones. Here, we have reinforced CBE with different weight proportions of silicon carbide to improve the mechanical characteristics of the composite. The hybrid of CBE (oxide) and carbide (SiC) is sintered at different temperatures to understand the effect of the interface of the two ceramics. It is observed that temperature has minimal effect and composition has a noticeable effect on mechanical strength as well as bio-toxicity. The toughness (∼3.58 MJ/m3) and compressive strength (∼64.64 MPa) of the 90:10 composition sintered at 1250 °C show the maximum optimum values. A mathematical model has also been developed to predict and correlate the toughness with porosity, volumetric loading, and elastic modulus of the 3D-printed ceramic composite.

Costal Cartilage Considerations: Novel Use of Handheld Ultrasound Device in Rhinoplasty.

Handheld ultrasound devices can be used in revision rhinoplasty to evaluate the calcification of costal rib cartilage that is to be harvested for grafting. This article provides instructions on how to perform this technique. Laryngoscope, 134:651-653, 2024.

Proteinuria in predicting adverse outcomes in women with severe features of pre-eclampsia from a developing country: A prospective cohort study.

OBJECTIVE: To study the adverse maternal and perinatal outcomes in women with severe pre-eclampsia (SPE) among different ranges of proteinuria. METHODS: This prospective cohort study was conducted in Jawaharlal Institute of Postgraduate Medical Education and Research, India. After obtaining informed written consent, the 202 singleton women fulfilling the criteria of severe features of pre-eclampsia were stratified based on the value of urine protein-creatinine ratio (UPCR) as mild, moderate, severe, and massive proteinuria during pregnancy. Clinical outcomes were assessed and patients were followed up until 12 weeks postpartum to identify persistent proteinuria and hypertension. RESULTS: Of the 202 women with SPE, adverse maternal outcomes were seen in 34.65% (n = 70) and adverse perinatal outcomes in 75.74% (n = 153). The demographic and clinical factors were similar among women with increasing severity of proteinuria, except for mean systolic blood pressure, serum creatinine and total serum protein. UPCR was found to have a significant correlation with composite adverse perinatal outcome (P < 0.001) and individual outcomes of neonatal intensive care unit admission for >48 h (P = 0.01) and neonatal sepsis (P = 0.02) but not adverse maternal outcomes (P = 0.201). The optimum UPCR cutoff for adverse perinatal outcomes was 1.6 (sensitivity, 73.2%; specificity, 52.7%). In addition, 14.85% of the women had a persistently elevated UPCR and 3.96% had hypertension at 3 months postpartum. CONCLUSION: In women with SPE, severe and massive proteinuria were related to composite adverse perinatal outcome but not composite adverse maternal outcome. Moreover, antenatal 24-h proteinuria was significantly associated with persistent proteinuria. Significant proteinuria in women with SPE poses a risk for chronic renal dysfunction, requiring follow-up.

Gene deletion of the PACAP/VIP receptor, VPAC2R, alters glycemic responses during metabolic and psychogenic stress in adult female mice.

Pituitary adenylate cyclase-activating polypeptide (PACAP) and the homologous peptide, vasoactive intestinal peptide (VIP), participate in glucose homeostasis using insulinotropic and counterregulatory processes. The role of VIP receptor 2 (VPAC2R) in these opposing actions needs further characterization. In this study, we examined the participation of VPAC2R on basal glycemia, fasted levels of glucoregulatory hormones and on glycemia responses during metabolic and psychogenic stress using gene-deleted (Vipr2-/- ) female mice. The mean basal glycemia was significantly greater in Vipr2-/- in the fed state and after an 8-h overnight fast as compared to wild-type (WT) mice. Insulin tolerance testing following a 5-h fast (morning fast, 0.38 U/kg insulin) indicated no effect of genotype. However, during a more intense metabolic challenge (8 h, ON fast, 0.25 U/kg insulin), Vipr2-/- females displayed significantly impaired insulin hypoglycemia. During immobilization stress, the hyperglycemic response and plasma epinephrine levels were significantly elevated above basal in Vipr2-/- , but not WT mice, in spite of similar stress levels of plasma corticosterone. Together, these results implicate participation of VPAC2R in upregulated counterregulatory processes influenced by enhanced sympathoexcitation. Moreover, the suppression of plasma GLP-1 levels in Vipr2-/- mice may have removed the inhibition on hepatic glucose production and the promotion of glucose disposal by GLP-1. qPCR analysis indicated deregulation of central gene markers of PACAP/VIP signaling in Vipr2-/- , upregulated medulla tyrosine hydroxylase (Th) and downregulated hypothalamic Vip transcripts. These results demonstrate a physiological role for VPAC2R in glucose metabolism, especially during insulin challenge and psychogenic stress, likely involving the participation of sympathoadrenal activity and/or metabolic hormones.

Thalamic nucleus reuniens coordinates prefrontal-hippocampal synchrony to suppress extinguished fear.

Traumatic events result in vivid and enduring fear memories. Suppressing the retrieval of these memories is central to behavioral therapies for pathological fear. The medial prefrontal cortex (mPFC) and hippocampus (HPC) have been implicated in retrieval suppression, but how mPFC-HPC activity is coordinated during extinction retrieval is unclear. Here we show that after extinction training, coherent theta oscillations (6-9 Hz) in the HPC and mPFC are correlated with the suppression of conditioned freezing in male and female rats. Inactivation of the nucleus reuniens (RE), a thalamic hub interconnecting the mPFC and HPC, reduces extinction-related Fos expression in both the mPFC and HPC, dampens mPFC-HPC theta coherence, and impairs extinction retrieval. Conversely, theta-paced optogenetic stimulation of RE augments fear suppression and reduces relapse of extinguished fear. Collectively, these results demonstrate a role for RE in coordinating mPFC-HPC interactions to suppress fear memories after extinction.

Cortical thickness is related to cognitive-motor automaticity and attention allocation in individuals with Alzheimer's disease: a regions of interest study.

Alzheimer's disease (AD) is characterized by a distinct pattern of cortical thinning and resultant changes in cognition and function. These result in prominent deficits in cognitive-motor automaticity. The relationship between AD-related cortical thinning and decreased automaticity is not well-understood. We aimed to investigate the relationship between cortical thickness regions-of-interest (ROI) and automaticity and attention allocation in AD using hypothesis-driven and exploratory approaches. We performed an ROI analysis of 46 patients with AD. Data regarding MR images, demographic characteristics, cognitive-motor dual task performance, and cognition were extracted from medical records. Cortical thickness was calculated from MR T1 images using FreeSurfer. Data from the dual task assessment was used to calculate the combined dual task effect (cDTE), a measure of cognitive-motor automaticity, and the modified attention allocation index (mAAI). Four hierarchical multiple linear regression models were conducted regressing cDTE and mAAI separately on (1) hypothesis-generated ROIs and (2) exploratory ROIs. For cDTE, cortical thicknesses explained 20.5% (p = 0.014) and 25.9% (p = 0.002) variability in automaticity in the hypothesized ROI and exploratory models, respectively. The dorsal lateral prefrontal cortex (DLPFC) (ß = - 0.479, p = 0.018) and superior parietal cortex (SPC) (ß = 0.467, p = 0.003), and were predictors of automaticity. For mAAI, cortical thicknesses explained 20.7% (p = 0.025) and 28.3% (p = 0.003) variability in attention allocation in the hypothesized ROI and exploratory models, respectively. Thinning of SPC and fusiform gyrus were associated with motor prioritization (ß = - 0.405, p = 0.013 and ß = - 0.632, p = 0.004, respectively), whereas thinning of the DLPFC was associated with cognitive prioritization (ß = 0.523, p = 0.022). Cortical thinning in AD was related to cognitive-motor automaticity and task prioritization, particularly in the DLPFC and SPC. This suggests that these regions may play a primary role in automaticity and attentional strategy during dual-tasking.

Automatic Detection of Alzheimer's Disease using Deep Learning Models and Neuro-Imaging: Current Trends and Future Perspectives.

Deep learning algorithms have a huge influence on tackling research issues in the field of medical image processing. It acts as a vital aid for the radiologists in producing accurate results toward effective disease diagnosis. The objective of this research is to highlight the importance of deep learning models in the detection of Alzheimer's Disease (AD). The main objective of this research is to analyze different deep learning methods used for detecting AD. This study examines 103 research articles published in various research databases. These articles have been selected based on specific criteria to find the most relevant findings in the field of AD detection. The review was carried out based on deep learning techniques such as Convolutional Neural Networks (CNNs), Recurrent Neural Networks (RNNs), and Transfer Learning (TL). To propose accurate methods for the detection, segmentation, and severity grading of AD, the radiological features need to be examined in greater depth. This review attempts to analyze different deep learning methods applied for AD detection using neuroimaging modalities like Positron Emission Tomography (PET), Magnetic Resonance Imaging (MRI), etc. The focus of this review is restricted to deep learning works based on radiological imaging data for AD detection. There are a few works that have utilized other biomarkers to understand the effect of AD. Also, articles published in English were alone considered for analysis. This work concludes by highlighting the key research issues towards effective AD detection. Though several methods have yielded promising results in AD detection, the progression from Mild Cognitive Impairment (MCI) to AD need to be analyzed in greater depth using DL models.

Persisting Effects in Daphnia magna Following an Acute Exposure to Flowback and Produced Waters from the Montney Formation.

Hydraulic fracturing extracts oil and gas through the injection of water and proppants into subterranean formations. These injected fluids mix with the host rock formation and return to the surface as a complex wastewater containing salts, metals, and organic compounds, termed flowback and produced water (FPW). Previous research indicates that FPW is toxic to Daphnia magna (D. magna), impairing reproduction, molting, and maturation time; however, recovery from FPW has not been extensively studied. Species unable to recover have drastic impacts on populations on the ecological scale; thus, this study sought to understand if recovery from an acute 48 h FPW exposure was possible in the freshwater invertebrate, D. magna by using a combination of physiological and molecular analyses. FPW (0.75%) reduced reproduction by 30% and survivorship to 32% compared to controls. System-level quantitative proteomic analyses demonstrate extensive perturbation of metabolism and protein transport in both 0.25 and 0.75% FPW treatments after a 48 h FPW exposure. Collectively, our data indicate that D. magna are unable to recover from acute 48 h exposures to ≥0.25% FPW, as evidence of toxicity persists for at least 19 days post-exposure. This study highlights the importance of considering persisting effects following FPW remediation when modeling potential spill scenarios.

Anthropogenic marine litter: An approach to environmental quality for India's southeastern Arabian Sea coast.

Anthropogenic marine litter (AML), mainly plastic, is a global concern that is persistent and widespread. To prevent and mitigate this threat, we need to understand the magnitude and source of AML. There is limited knowledge about AML pollution on the Indian Coast. In this context, the present study examined the distribution, abundance, typology, and beach quality based on AML along 22 beaches on the southeastern coast of the Arabian Sea. A total of 4911 AML items were classified into 9 categories, weighing 16.79 kg, and retrieved from a total area of 8000 m2. The mean abundance and weight of AML in the current study were 0.45 ± 0.34 items/m2 and 1.53 ± 0.92 g/m2, respectively. Thottapally showed the most abundant AML among the studied beaches with 0.96 items/m2, followed by Azheekkal with 0.73 items/m2. Plastic, being the most common item, accounts for 77.6 % of all items and has a mean density of 0.35 items/m2 comprising hard plastic (22 %), thermocol (13 %), food wrappers (7 %), cigarette butts (7 %), plastic rope (6 %), and plastic cutlery (6 %). Hazardous anthropogenic litter (HAL) was maximum at Thottapally (17.71 %; 85 out of 480 items collected). Based on the cleanliness of beaches, they are graded "moderately clean" (63 %) by the General Index (GI), "clean" (54 %), and "moderately clean" (40 %) as calculated by the Clean Coast Index (CCI). Hazardous Anthropogenic Beach Litter Index (HABLI) classifies 72 % of beaches as "moderately safe", while the Environmental Status Index (ESI) rates 68 % of beaches as "mediocre". Besides, model simulations demonstrated the pathways of AML propagation, which correlate to the littoral and coastal current flow patterns over the region. Land-based activities were the crucial factors influencing AML distribution. The study highlighted the need for effective regional litter management strategies, policy instruments for the litter impact pathways, economic, regulatory, and behavioural management tools, which were also discussed.

Electromechanical Cornea Reshaping for Refractive Vision Therapy.

The corneal stroma consists of orthogonally stacked collagen-fibril lamellae that determine the shape of the cornea and provide most of the refractive power of the eye. We have applied electromechanical reshaping (EMR), an electrochemical platform for remodeling cartilage and other semirigid tissues, to change the curvature of the cornea as a potential procedure for nonsurgical vision correction. EMR relies on short electrochemical pulses to electrolyze water, with subsequent diffusion of protons into the extracellular matrix of collagenous tissues; protonation of immobilized anions within this matrix disrupts the ionic-bonding network, leaving the tissue transiently responsive to mechanical remodeling. Re-equilibration to physiological pH restores the ionic matrix, resulting in persistent shape change of the tissue. Using ex vivo rabbit eyes, we demonstrate here the controlled change of corneal curvature over a wide range of refractive powers with no loss of optical transparency. Optical coherence tomography (OCT), combined with second-harmonic generation (SHG) and confocal microscopy, establish that EMR enables extremely fine control of corneal contouring while maintaining the underlying macromolecular collagen structure and stromal cellular viability, positioning electrochemical vision therapy as a potentially simple and ultralow-cost modality for correcting routine refractive errors.

Arteriovenous fistula aneurysmorrhaphy is associated with improved patency and decreased vascular access abandonment.

BACKGROUND: Upper extremity hemodialysis arteriovenous fistulas (AVFs) can become aneurysmal over time due to repeated cannulation and/or outflow steno-occlusive disease. The optimal surgical management of aneurysmal AVFs (aneurysmorrhaphy vs interposition graft) has remained unclear. METHODS: We performed a retrospective review in which current procedural terminology codes were used to screen for patients who had undergone surgical treatment of aneurysmal AVFs between 2016 and 2021 at a single hospital system. The patients were included after a review of the operative reports. The cases were divided by surgical procedure (aneurysmorrhaphy vs interposition graft placement). The patients who had undergone primary AVF ligation or other types of repair were excluded. The primary outcomes were primary assisted and secondary patency, and the secondary outcome was dialysis access abandonment. Multivariable Cox proportional hazards regression was used to test the association between the type of AVF aneurysm repair and the primary and secondary outcomes. RESULTS: From 2016 to 2021, 6951 patients had undergone 16,190 dialysis access procedures. Of these procedures, 381 (2.4%) were related to surgical treatment of an aneurysmal AVF. We excluded 58 primary AVF ligation cases and 20 cases involving other types of repair, leaving 303 cases for analysis. These were divided into two groups: aneurysmorrhaphy (n = 123; 41%) and interposition graft (n = 180; 59%). No differences were found between the groups in male gender (68% vs 63%), hypertension (98% vs 98%), or central stenosis (14% vs 22%). The patients who had undergone aneurysmorrhaphy were younger (median age, 54 years vs 59 years); had had a lower rate of diabetes (41% vs 59%), coronary artery disease (41% vs 58%), and congestive heart failure (41% vs 55%); and were less likely to have undergone upper arm access (72% vs 92%). The median follow-up was 11.1 months (interquartile range, 3.6-25.2 months). No differences were found in the incidence of 30-day wound complications (1% vs 3%) or surgical site infections (4% vs 6%). On multivariable Cox regression, interposition graft placement was associated with the loss of primary assisted patency (adjusted hazard ratio [aHR], 2.42; 95% confidence interval [CI], 1.18-4.95), loss of secondary patency (aHR, 3.10; 95% CI, 1.21-7.94), and abandonment of dialysis access (aHR, 3.07; 95% CI, 1.61-5.87; P < .05 for all) at 2 years. CONCLUSIONS: AVF aneurysmorrhaphy was associated with improved primary assisted and secondary patency and decreased abandonment of dialysis access. We suggest using aneurysmorrhaphy when AVF aneurysms are indicated for repair. However, individual factors such as patient comorbidities, AVF anatomy, remaining dialysis access options, and patient preference should be considered when planning the surgical approach.

Prognostic Utility of Tumor Stage versus American Thyroid Association Risk Class in Thyroid Cancer.

OBJECTIVE: To evaluate the prognostic strengths of American Joint Committee on Cancer (AJCC) staging and American Thyroid Association (ATA) risk classification in well-differentiated thyroid cancer (DTC), and their implications in guiding medical decision-making and epidemiological study designs. METHODS: The 2004-2017 National Cancer Database was queried for DTC patients. Cox proportional hazards (CPH) and Kaplan-Meier analyses modeled patient mortality and overall survival, respectively. Each CPH model was evaluated by its concordance index, measure of explained randomness (MER), Akaike information criterion (AIC), and area under receiver operating characteristic curve (AUC). RESULTS: Overall, 134,226 patients were analyzed, with an average age of 48.1 ± 15.1 years (76.9% female). Univariate CPH models using AJCC staging demonstrated higher concordance indices, MERs, and AUCs than those using ATA risk classification (all p < 0.001). Multivariable CPH models using AJCC staging demonstrated higher concordance indices (p = 0.049), MERs (p = 0.046), and AUCs (p = 0.002) than those using ATA risk classification. The AICs of multivariable AJCC staging and ATA risk models were 7.564 × 104 and 7.603 × 104 , respectively. AJCC stage I tumors were associated with greater overall survival than those classified as ATA low risk, whereas AJCC stages II-III and stage IV tumors demonstrated worse survival than ATA intermediate- and high-risk tumors, respectively (all p < 0.001). CONCLUSION: AJCC staging may be a more predictive system for patient survival than ATA risk. The prognostic utility of these two systems converges when additional demographic and clinical factors are considered. AJCC staging was found to classify patients across a wider range of survival patterns than the ATA risk stratification system. LEVEL OF EVIDENCE: 4 Laryngoscope, 133:205-211, 2023.

Probiotic Escherichia coli Nissle 1917 alleviates the neurotoxicity caused by acrylamide in zebrafish.

Neurotoxicity is caused by damage to the brain tissue by neurotoxic agents present in the environment and artificial substances produced by human beings. Acrylamide (ACR) is one such chemical substance that causes neurotoxicity, affecting the brain cells. This neurotoxicity causes damage to the sensory and metabolic functions. The current research investigates the favourable effect of probiotic EcN (Escherichia coli Nissle 1917) on ACR-induced neurotoxicity in zebrafish. The protective role of EcN against ACR induced toxicity was assessed based on behaviour, biochemical, and gene expression analysis. Initially, the colonisation period of EcN in the zebrafish gut was determined and EcN was given orally to the zebrafish only once prior to the ACR treatment. Very interestingly, this dosage was able to ameliorate the adverse effects of ACR significantly in the brain cells. Quantification of oxidative stress and neuronal cell death clearly vindicate the efficiency of probiotic EcN in reversing the damages caused by ACR. EcN is being explored largely in recent days for its therapeutic applications. This study strongly supports the view that EcN can be developed as a supplement to the patients diagnosed with neuronal cell toxicity.

Manual small-incision cataract surgery under topical anesthesia for post-uveitis complicated cataract.

Purpose: Cataract development is a common sequelae associated with uveitis. Despite phacoemulsification being the popular method of cataract surgery today, manual small-incision cataract surgery (MSICS) may still be a safe and effective alternative because of several inherent benefits. There is not much literature and studies on the efficacy and safety of MSICS under topical anesthesia in complicated cataract in patients with uveitis. We aimed to study the safety and visual outcome of MSICS under topical anesthesia for post uveitis complicated cataract. Methods: This was a retrospective observational study. The electronic medical records of adult patients who underwent MSICS under topical anesthesia for post uveitis cataract were reviewed. The records were reviewed and analyzed for preoperative clinical characteristics and visual acuity, intraoperative complications and postoperative visual acuity, and complications. Results: A total of 71 eyes of 59 patients were taken for final analysis. The average age of patients was 59.9 years. There was improvement in the best corrected visual acuity by 0.7 logMAR (P value <0.0001). Average follow-up period was 9.8 months. The mean gain in visual acuity in eyes that received preoperative steroids was 0.6 logMAR compared to the eyes that did not receive steroids (0.71 logMAR). The difference was not statistically significant (P = 0.407). Complications seen during long-term follow-up were recurrence (15.5%), cystoid macular edema (7%), Epiretinal membrane (8.5%), and posterior capsular opacification (5.5%). Conclusion: With proper technique and precautions, MSICS can be safely and comfortably performed under topical anesthesia even in complicated cataracts with excellent visual and safety outcomes.

Optical-Tweezers-integrating-Differential-Dynamic-Microscopy maps the spatiotemporal propagation of nonlinear strains in polymer blends and composites.

How local stresses propagate through polymeric fluids, and, more generally, how macromolecular dynamics give rise to viscoelasticity are open questions vital to wide-ranging scientific and industrial fields. Here, to unambiguously connect polymer dynamics to force response, and map the deformation fields that arise in macromolecular materials, we present Optical-Tweezers-integrating-Differential -Dynamic-Microscopy (OpTiDMM) that simultaneously imposes local strains, measures resistive forces, and analyzes the motion of the surrounding polymers. Our measurements with blends of ring and linear polymers (DNA) and their composites with stiff polymers (microtubules) uncover an unexpected resonant response, in which strain alignment, superdiffusivity, and elasticity are maximized when the strain rate is comparable to the entanglement rate. Microtubules suppress this resonance, while substantially increasing elastic storage, due to varying degrees to which the polymers buildup, stretch and flow along the strain path, and configurationally relax induced stress. More broadly, the rich multi-scale coupling of mechanics and dynamics afforded by OpTiDDM, empowers its interdisciplinary use to elucidate non-trivial phenomena that sculpt stress propagation dynamics-critical to commercial applications and cell mechanics alike.

Macrophage TGF-ß signaling is critical for wound healing with heterotopic ossification after trauma.

Transforming growth factor-ß1 (TGF-ß1) plays a central role in normal and aberrant wound healing, but the precise mechanism in the local environment remains elusive. Here, using a mouse model of aberrant wound healing resulting in heterotopic ossification (HO) after traumatic injury, we find autocrine TGF-ß1 signaling in macrophages, and not mesenchymal stem/progenitor cells, is critical in HO formation. In-depth single-cell transcriptomic and epigenomic analyses in combination with immunostaining of cells from the injury site demonstrated increased TGF-ß1 signaling in early infiltrating macrophages, with open chromatin regions in TGF-ß1-stimulated genes at binding sites specific for transcription factors of activated TGF-ß1 (SMAD2/3). Genetic deletion of TGF-ß1 receptor type 1 (Tgfbr1; Alk5), in macrophages, resulted in increased HO, with a trend toward decreased tendinous HO. To bypass the effect seen by altering the receptor, we administered a systemic treatment with TGF-ß1/3 ligand trap TGF-ßRII-Fc, which resulted in decreased HO formation and a delay in macrophage infiltration to the injury site. Overall, our data support the role of the TGF-ß1/ALK5 signaling pathway in HO.

Nucleus reuniens inactivation does not impair consolidation or reconsolidation of fear extinction.

Recent data reveal that the thalamic nucleus reuniens (RE) has a critical role in the extinction of conditioned fear. Muscimol (MUS) infusions into the RE impair within-session extinction of conditioned freezing and result in poor long-term extinction memories in rats. Although this suggests that RE inactivation impairs extinction learning, it is also possible that it is involved in the consolidation of extinction memories. To examine this possibility, we examined the effects of RE inactivation on the consolidation and reconsolidation of fear extinction in male and female rats. Twenty-four hours after auditory fear conditioning, rats underwent an extinction procedure (45 CS-alone trials) in a novel context and were infused with saline (SAL) or MUS within minutes of the final extinction trial. Twenty-four hours later, conditioned freezing to the extinguished CS was assessed in the extinction context. Postextinction inactivation of the RE did not affect extinction retrieval. In a second experiment, rats underwent extinction training and, 24 h later, were presented with a single CS to reactivate the extinction memory; rats were infused with SAL or MUS immediately after the reactivation session. Pharmacological inactivation of the RE did not affect conditioned freezing measured in a drug-free retrieval test the following day. Importantly, we found in a subsequent test that MUS infusions immediately before retrieval testing increased conditioned freezing and impaired extinction retrieval, as we have previously reported. These results indicate that although RE inactivation impairs the expression of extinction, it does not impair either the consolidation or reconsolidation of extinction memories. We conclude that the RE may have a critical role in suppressing context-inappropriate fear memories in the extinction context.

CT-based severity assessment for COVID-19 using weakly supervised non-local CNN.

Evaluating patient criticality is the foremost step in administering appropriate COVID-19 treatment protocols. Learning an Artificial Intelligence (AI) model from clinical data for automatic risk-stratification enables accelerated response to patients displaying critical indicators. Chest CT manifestations including ground-glass opacities and consolidations are a reliable indicator for prognostic studies and show variability with patient condition. To this end, we propose a novel attention framework to estimate COVID-19 severity as a regression score from a weakly annotated CT scan dataset. It takes a non-locality approach that correlates features across different parts and spatial scales of the 3D scan. An explicit guidance mechanism from limited infection labeling drives attention refinement and feature modulation. The resulting encoded representation is further enriched through cross-channel attention. The attention model also infuses global contextual awareness into the deep voxel features by querying the base CT scan to mine relevant features. Consequently, it learns to effectively localize its focus region and chisel out the infection precisely. Experimental validation on the MosMed dataset shows that the proposed architecture has significant potential in augmenting existing methods as it achieved a 0.84 R-squared score and 0.133 mean absolute difference.

Microplastic pollution in fragile coastal ecosystems with special reference to the X-Press Pearl maritime disaster, southeast coast of India.

Microplastics (MPs) are a global environmental concern and pose a serious threat to marine ecosystems. This study aimed to determine the abundance and distribution of MPs in beach sediments (12 beaches), marine biota (6 beaches) and the influence of microbes on MPs degradation in eco-sensitive Palk Bay and Gulf of Mannar coast. The mean MP abundance 65.4 ± 39.8 particles/m2 in beach sediments; 0.19 ± 1.3 particles/individual fish and 0.22 ± 0.11 particles g-1 wet weight in barnacles. Polyethylene fragments (33.4%) and fibres (48%) were the most abundant MPs identified in sediments and finfish, respectively. Histopathological examination of fish has revealed health consequences such as respiratory system damage, epithelial degradation and enterocyte vacuolization. In addition, eight bacterial and seventeen fungal strains were isolated from the beached MPs. The results also indicated weathering of MPs due to microbial interactions. Model simulations helped in tracking the fate and transboundary landfall of spilled MPs across the Indian Ocean coastline after the X-Press Pearl disaster. Due to regional circulations induced by the monsoonal wind fields, a potential dispersal of pellets has occurred along the coast of Sri Lanka, but no landfall and ecological damage are predicted along the coast of India.

Contour-enhanced attention CNN for CT-based COVID-19 segmentation.

Accurate detection of COVID-19 is one of the challenging research topics in today's healthcare sector to control the coronavirus pandemic. Automatic data-powered insights for COVID-19 localization from medical imaging modality like chest CT scan tremendously augment clinical care assistance. In this research, a Contour-aware Attention Decoder CNN has been proposed to precisely segment COVID-19 infected tissues in a very effective way. It introduces a novel attention scheme to extract boundary, shape cues from CT contours and leverage these features in refining the infected areas. For every decoded pixel, the attention module harvests contextual information in its spatial neighborhood from the contour feature maps. As a result of incorporating such rich structural details into decoding via dense attention, the CNN is able to capture even intricate morphological details. The decoder is also augmented with a Cross Context Attention Fusion Upsampling to robustly reconstruct deep semantic features back to high-resolution segmentation map. It employs a novel pixel-precise attention model that draws relevant encoder features to aid in effective upsampling. The proposed CNN was evaluated on 3D scans from MosMedData and Jun Ma benchmarked datasets. It achieved state-of-the-art performance with a high dice similarity coefficient of 85.43% and a recall of 88.10%.