Noninvasive Assessment of Diabetic Kidney Disease With MRI: Hype or Hope?

Owing to the increasing prevalence of diabetic mellitus, diabetic kidney disease (DKD) is presently the leading cause of chronic kidney disease and end-stage renal disease worldwide. Early identification and disease interception is of paramount clinical importance for DKD management. However, current diagnostic, disease monitoring and prognostic tools are not satisfactory, due to their low sensitivity, low specificity, or invasiveness. Magnetic resonance imaging (MRI) is noninvasive and offers a host of contrast mechanisms that are sensitive to pathophysiological changes and risk factors associated with DKD. MRI tissue characterization involves structural and functional information including renal morphology (kidney volume (TKV) and parenchyma thickness using T1- or T2-weighted MRI), renal microstructure (diffusion weighted imaging, DWI), renal tissue oxygenation (blood oxygenation level dependent MRI, BOLD), renal hemodynamics (arterial spin labeling and phase contrast MRI), fibrosis (DWI) and abdominal or perirenal fat fraction (Dixon MRI). Recent (pre)clinical studies demonstrated the feasibility and potential value of DKD evaluation with MRI. Recognizing this opportunity, this review outlines key concepts and current trends in renal MRI technology for furthering our understanding of the mechanisms underlying DKD and for supplementing clinical decision-making in DKD. Progress in preclinical MRI of DKD is surveyed, and challenges for clinical translation of renal MRI are discussed. Future directions of DKD assessment and renal tissue characterization with (multi)parametric MRI are explored. Opportunities for discovery and clinical break-through are discussed including biological validation of the MRI findings, large-scale population studies, standardization of DKD protocols, the synergistic connection with data science to advance comprehensive texture analysis, and the development of smart and automatic data analysis and data visualization tools to further the concepts of virtual biopsy and personalized DKD precision medicine. We hope that this review will convey this vision and inspire the reader to become pioneers in noninvasive assessment and management of DKD with MRI. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY: Stage 2.

The non-covalent and covalent interactions of whey proteins and saccharides: influencing factor and utilization in food.

During the application of Whey proteins (WPs), they often have complex interactions with saccharides (Ss), another important biopolymer in food substrate. The texture and sensory qualities of foods containing WPs and Ss are largely influenced by the interactions of WPs-Ss. Moreover, the combination of WPs and Ss is possible to produce many excellent functional properties including emulsifying properties and thermal stability. However, the interactions between WPs-Ss are complex and susceptible to some processing conditions. In addition, with different interaction ways, they can be applied in different fields. Therefore, the non-covalent interaction mechanisms between WPs-Ss are firstly summarized in detail, including electrostatic interaction, hydrogen bond, hydrophobic interaction, van der Waals force. Furthermore, the existence modes of WPs-Ss are introduced, including complex coacervates, soluble complexes, segregation, and co-solubility. The covalent interactions of WPs-Ss in food applications are often formed by Maillard reaction (dry or wet heat reaction) and occasionally through enzyme induction. Then, two common influencing factors, pH and temperature, on non-covalent/covalent bonds are introduced. Finally, the applications of WPs-Ss complexes and conjugations in improving WP stability, delivery system, and emulsification are described. This review can improve our understanding of the interactions between WPs-Ss and further promote their wider application.

MRI of kidney size matters.

OBJECTIVE: To highlight progress and opportunities of measuring kidney size with MRI, and to inspire research into resolving the remaining methodological gaps and unanswered questions relating to kidney size assessment. MATERIALS AND METHODS: This work is not a comprehensive review of the literature but highlights valuable recent developments of MRI of kidney size. RESULTS: The links between renal (patho)physiology and kidney size are outlined. Common methodological approaches for MRI of kidney size are reviewed. Techniques tailored for renal segmentation and quantification of kidney size are discussed. Frontier applications of kidney size monitoring in preclinical models and human studies are reviewed. Future directions of MRI of kidney size are explored. CONCLUSION: MRI of kidney size matters. It will facilitate a growing range of (pre)clinical applications, and provide a springboard for new insights into renal (patho)physiology. As kidney size can be easily obtained from already established renal MRI protocols without the need for additional scans, this measurement should always accompany diagnostic MRI exams. Reconciling global kidney size changes with alterations in the size of specific renal layers is an important topic for further research. Acute kidney size measurements alone cannot distinguish between changes induced by alterations in the blood or the tubular volume fractions-this distinction requires further research into cartography of the renal blood and the tubular volumes.

Inositol hexakisphosphate primes syndapin I/PACSIN 1 activation in endocytosis.

Endocytosis is controlled by a well-orchestrated molecular machinery, where the individual players as well as their precise interactions are not fully understood. We now show that syndapin I/PACSIN 1 is expressed in pancreatic ß cells and that its knockdown abrogates ß cell endocytosis leading to disturbed plasma membrane protein homeostasis, as exemplified by an elevated density of L-type Ca2+ channels. Intriguingly, inositol hexakisphosphate (InsP6) activates casein kinase 2 (CK2) that phosphorylates syndapin I/PACSIN 1, thereby promoting interactions between syndapin I/PACSIN 1 and neural Wiskott-Aldrich syndrome protein (N-WASP) and driving ß cell endocytosis. Dominant-negative interference with endogenous syndapin I/PACSIN 1 protein complexes, by overexpression of the syndapin I/PACSIN 1 SH3 domain, decreases InsP6-stimulated endocytosis. InsP6 thus promotes syndapin I/PACSIN 1 priming by CK2-dependent phosphorylation, which endows the syndapin I/PACSIN 1 SH3 domain with the capability to interact with the endocytic machinery and thereby initiate endocytosis, as exemplified in ß cells.

Enhanced expression of ß cell CaV3.1 channels impairs insulin release and glucose homeostasis.

Voltage-gated calcium 3.1 (CaV3.1) channels are absent in healthy mouse ß cells and mediate minor T-type Ca2+ currents in healthy rat and human ß cells but become evident under diabetic conditions. Whether more active CaV3.1 channels affect insulin secretion and glucose homeostasis remains enigmatic. We addressed this question by enhancing de novo expression of ß cell CaV3.1 channels and exploring the consequent impacts on dynamic insulin secretion and glucose homeostasis as well as underlying molecular mechanisms with a series of in vitro and in vivo approaches. We now demonstrate that a recombinant adenovirus encoding enhanced green fluorescent protein-CaV3.1 subunit (Ad-EGFP-CaV3.1) efficiently transduced rat and human islets as well as dispersed islet cells. The resulting CaV3.1 channels conducted typical T-type Ca2+ currents, leading to an enhanced basal cytosolic-free Ca2+ concentration ([Ca2+]i). Ad-EGFP-CaV3.1-transduced islets released significantly less insulin under both the basal and first phases following glucose stimulation and could no longer normalize hyperglycemia in recipient rats rendered diabetic by streptozotocin treatment. Furthermore, Ad-EGFP-CaV3.1 transduction reduced phosphorylated FoxO1 in the cytoplasm of INS-1E cells, elevated FoxO1 nuclear retention, and decreased syntaxin 1A, SNAP-25, and synaptotagmin III. These effects were prevented by inhibiting CaV3.1 channels or the Ca2+-dependent phosphatase calcineurin. Enhanced expression of ß cell CaV3.1 channels therefore impairs insulin release and glucose homeostasis by means of initial excessive Ca2+ influx, subsequent activation of calcineurin, consequent dephosphorylation and nuclear retention of FoxO1, and eventual FoxO1-mediated down-regulation of ß cell exocytotic proteins. The present work thus suggests an elevated expression of CaV3.1 channels plays a significant role in diabetes pathogenesis.

Diffusion-weighted magnetic resonance imaging in rat kidney using two-dimensional navigated, interleaved echo-planar imaging at 7.0 T.

The purpose of this study was to investigate the feasibility of two-dimensional (2D) navigated, interleaved multishot echo-planar imaging (EPI) to enhance kidney diffusion-weighted imaging (DWI) in rats at 7.0 T. Fully sampled interleaved four-shot EPI with 2D navigators was tailored for kidney DWI (Sprague-Dawley rats, n = 7) on a 7.0-T small bore preclinical scanner. The image quality of four-shot EPI was compared with T2 -weighted rapid acquisition with relaxation enhancement (RARE) (reference) and single-shot EPI (ss-EPI) without and with parallel imaging (PI). The contrast-to-noise ratio (CNR) was examined to assess the image quality for the EPI approaches. The Dice similarity coefficient and the Hausdorff distance were used for evaluation of image distortion. Mean diffusivity (MD) and fractional anisotropy (FA) were calculated for renal cortex and medulla for all DWI approaches. The corticomedullary difference of MD and FA were assessed by Wilcoxon signed-rank test. Four-shot EPI showed the highest CNR among the three EPI variants and lowest geometric distortion versus T2 -weighted RARE (mean Dice: 0.77 for ss-EPI without PI, 0.88 for ss-EPI with twofold undersampling, and 0.92 for four-shot EPI). The FA map derived from four-shot EPI clearly identified a highly anisotropic region corresponding to the inner stripe of the outer medulla. Four-shot EPI successfully discerned differences in both MD and FA between renal cortex and medulla. In conclusion, 2D navigated, interleaved multishot EPI facilitates high-quality rat kidney DWI with clearly depicted intralayer and interlayer structure and substantially reduced image distortion. This approach enables the anatomic integrity of DWI-MRI in small rodents and has the potential to benefit the characterization of renal microstructure in preclinical studies.

A rethinking of collagen as tough biomaterials in meat packaging: assembly from native to synthetic.

Due to the high moisture-associated typical rheology and the changeable and harsh processing conditions in the production process, packaging materials for meat products have higher requirements including a sufficient mechanical strength and proper ductility. Collagen, a highly conserved structural protein consisting of a triple helix of Gly-X-Y repeats, has been proved to be suitable packaging material for meat products. The treated animal digestive tract (i.e. the casing) is the perfect natural packaging material for wrapping meat into sausage. Its thin walls, strong toughness and impact resistance make it the oldest and best edible meat packaging. Collagen casing is another wisdom of meat packaging, which is made by collagen fibers from hide skin, presenting a rapid growth in casing market. To strengthen mechanical strength and barrier behaviors of collagen-based packaging materials, different physical, chemical, and biological cross-linking methods are springing up exuberantly, as well as a variety of reinforcement approaches including nanotechnology. In addition, the rapid development of biomimetic technology also provides a good research idea and means for the promotion of collagen's assembly and relevant mechanical properties. This review can offer some reference on fundamental theory and practical application of collagenous materials in meat products.

Polyphenols and polyphenols-based biopolymer materials: Regulating iron absorption and availability from spontaneous to controllable.

Iron is an important trace element in the body, and it will seriously affect the body's normal operation if it is taken too much or too little. A large number of patients around the world are suffering from iron disorders. However, there are many problems using drugs to treat iron overload and causing prolonged and unbearable suffering for patients. Controlling iron absorption and utilization through diet is becoming the acceptable, safe and healthy method. At present, many literatures have reported that polyphenols can interact with iron ions and can be expected to chelate iron ions, depending on their types and structures. Besides, polyphenols often interact with other macromolecules in the diet, which may complicate this phenols-Fe behavior and give rise to the necessity of building phenolic based biopolymer materials. The biopolymer materials, constructed by self-assembly (non-covalent) or chemical modification (covalent), show excellent properties such as good permeability, targeting, biocompatibility, and high chelation ability. It is believed that this review can greatly facilitate the development of polyphenols-based biopolymer materials construction for regulating iron and improving the well-being of patients.

Physical Exercise Modalities for the Management of Heart Failure With Preserved Ejection Fraction: A Systematic Review and Meta-Analysis.

ABSTRACT: Different physical exercise modalities have been widely studied in patients having heart failure with preserved ejection fraction (HFpEF) but with variably reported findings. We, therefore, conducted a systematic review and meta-analysis to evaluate whether the efficacy of physical activity in the management of HFpEF is related to exercise modalities. PubMed and Embase were searched up to July 2021. The eligible studies included randomized controlled trials that identified effects of physical exercise on patients with HFpEF. Sixteen studies were included to evaluate the efficiency of physical exercise in HFpEF. A pooled analysis showed that exercise training significantly improved peak oxygen uptake (VO2), ventilatory anaerobic threshold, distance covered in the 6-minute walking test, the ratio of early diastolic mitral inflow to annular velocities, the Short Form 36 physical component score, and the Minnesota Living with Heart Failure Questionnaire total score. However, the changes in other echocardiographic parameters including the ratio of peak early to late diastolic mitral inflow velocities, early diastolic mitral annular velocity, and left atrial volume index were not significant. Both high-intensity and moderate-intensity training significantly improved exercise capacity (as defined by peak VO2), with moderate-intensity exercise having a superior effect. Furthermore, exercise-induced improvement in peak VO2 was partially correlated with exercise duration. Physical exercise could substantially improve exercise capacity, quality of life, and some indicators of cardiac diastolic function in patients with HFpEF. A protocol of moderate-intensity exercise training lasting a longer duration might be more beneficial compared with high-intensity training for patients with HFpEF.

Clinical efficacy and safety of robotic distal gastrectomy for gastric cancer: a systematic review and meta-analysis.

BACKGROUND: Robotic distal gastrectomy (RDG) is a new technique that is rapidly gaining popularity and may help overcome the limitations of laparoscopic distal gastrectomy (LDG); however, its safety and therapeutic efficacy remain controversial. Therefore, this meta-analysis was performed to evaluate the safety and efficacy of RDG. METHODS: We searched PubMed, EMBASE, the Cochrane Library, and Web of Science for studies that compared RDG and LDG and were published between the time of database inception and May 2021. We assessed the bias risk of the observational studies using ROBIN-I, and a random effect model was always applied. RESULTS: The meta-analysis included 22 studies involving 5386 patients. Compared with LDG, RDG was associated with longer operating time (Mean Difference [MD] = 43.88, 95% CI = 35.17-52.60), less intraoperative blood loss (MD = - 24.84, 95% CI = - 41.26 to - 8.43), a higher number of retrieved lymph nodes (MD = 2.41, 95% CI = 0.77-4.05), shorter time to first flatus (MD = - 0.09, 95% CI = - 0.15 to - 0.03), shorter postoperative hospital stay (MD = - 0.68, 95% CI = - 1.27 to - 0.08), and lower incidence of pancreatic fistula (OR = 0.23, 95% CI = 0.07-0.79). Mean proximal and distal resection margin distances, time to start liquid and soft diets, and other complications were not significantly different between RDG and LDG groups. However, in the propensity-score-matched meta-analysis, the differences in time to first flatus and postoperative hospital stay between the two groups lost significance. CONCLUSIONS: Based on the available evidence, RDG appears feasible and safe, shows better surgical and oncological outcomes than LDG and, comparable postoperative recovery and postoperative complication outcomes.

IgGs from patients with amyotrophic lateral sclerosis and diabetes target CaVα2δ1 subunits impairing islet cell function and survival.

Patients with amyotrophic lateral sclerosis (ALS) often show hallmarks of type 2 diabetes mellitus (T2DM). However, the causal link between ALS and T2DM has remained a mystery. We now demonstrate that 60% of ALS patients with T2DM (ALS-T2DM) have sera that exaggerated K+-induced increases in cytosolic free Ca2+ concentration ([Ca2+]i) in mouse islet cells. The effect was attributed to the presence of pathogenic immunoglobulin Gs (IgGs) in ALS-T2DM sera. The pathogenic IgGs immunocaptured the voltage-dependent Ca2+ (CaV) channel subunit CaVα2δ1 in the plasma membrane enhancing CaV1 channel-mediated Ca2+ influx and [Ca2+]i, resulting in impaired mitochondrial function. Consequently, impairments in [Ca2+]i dynamics, insulin secretion, and cell viability occurred. These data reveal that patients with ALS-T2DM carry cytotoxic ALS-T2DM-IgG autoantibodies that serve as a causal link between ALS and T2DM by immunoattacking CaVα2δ1 subunits. Our findings may lay the foundation for a pharmacological treatment strategy for patients suffering from a combination of these diseases.

Phosphodiesterase inhibitor for heart failure with preserved ejection fraction: A systematic review and meta-analysis.

Background: Although heart failure with preserved ejection fraction (HFpEF) is a serious disease, only limited options are available for its treatment. Recent studies have analyzed the effects of phosphodiesterase (PDE) inhibitors, especially PDE5 and PDE3 inhibitors, in patients with HFpEF, with mixed outcomes. Methods: We searched PUBMED and EMBASE databases up to August 2021. Randomized controlled trials (RCTs) and clinical trials that tested the effects of PDE inhibitors on patients with HFpEF were included as eligible studies. Indicators of left ventricular (LV) function, pulmonary arterial pressure (PAP), right ventricular (RV) function, exercise capacity, and quality of life (QOL) were used to evaluate the efficacy of PDE inhibitors in HFpEF. Results: Six RCTs that reported in 7 studies were included to evaluate the efficiency of PDE inhibitors on HFpEF patients. In the pooled analysis, PDE inhibitors showed insignificant changes in the ratio of early diastolic mitral inflow to annular velocities, left atrial volume index, pulmonary artery systolic pressure (PASP), pulmonary vascular resistance (PVR), peak oxygen uptake, 6-minute walking test distance, as well as Kansas City Cardiomyopathy Questionnaire score. However, substantial improvement was observed in the tricuspid annular plane systolic excursion (TAPSE). Additionally, the regression analysis showed that PDE inhibitor administration time is a critical factor for the decrease in PASP. Conclusions: PDE inhibitors did not effectively improve LV function, PAP, exercise capacity, and QOL in patients with HFpEF. However, they improved RV function with significant difference, suggesting that PDE inhibitors might be a promising option for HFpEF patients with RV dysfunction.

Physiological system analysis of the kidney by high-temporal-resolution T2∗ monitoring of an oxygenation step response.

PURPOSE: Examine the feasibility of characterizing the regulation of renal oxygenation using high-temporal-resolution monitoring of the T2∗ response to a step-like oxygenation stimulus. METHODS: For T2∗ mapping, multi-echo gradient-echo imaging was used (temporal resolution = 9 seconds). A step-like renal oxygenation challenge was applied involving sequential exposure to hyperoxia (100% O2 ), hypoxia (10% O2 + 90% N2 ), and hyperoxia (100% O2 ). In vivo experiments were performed in healthy rats (N = 10) and in rats with bilateral ischemia-reperfusion injury (N = 4). To assess the step response of renal oxygenation, a second-order exponential model was used (model parameters: amplitude [A], time delay [Δt], damping constant [D], and period of the oscillation [T]) for renal cortex, outer stripe of the outer medulla, inner stripe of the outer medulla, and inner medulla. RESULTS: The second-order exponential model permitted us to model the exponential T2∗ recovery and the superimposed T2∗ oscillation following renal oxygenation stimulus. The in vivo experiments revealed a difference in Douter medulla between healthy controls (D < 1, indicating oscillatory recovery) and ischemia-reperfusion injury (D > 1, reflecting aperiodic recovery). The increase in Douter medulla by a factor of 3.7 (outer stripe of the outer medulla) and 10.0 (inner stripe of the outer medulla) suggests that this parameter might be rather sensitive to (patho)physiological oxygenation changes. CONCLUSION: This study demonstrates the feasibility of monitoring the dynamic oxygenation response of renal tissues to a step-like oxygenation challenge using high-temporal-resolution T2∗ mapping. Our results suggest that the implemented system analysis approach may help to unlock questions regarding regulation of renal oxygenation, with the ultimate goal of providing imaging means for diagnostics and therapy of renal diseases.

Emerging Yttrium Phosphides with Tetrahedron Phosphorus and Superconductivity under High Pressures.

Metal phosphides have triggered growing interest for their exotic structures and striking properties. Hence, within advanced structure search and first-principle calculations, several unprecedented Y-P compounds (e. g., Y3 P, Y2 P, Y3 P2 , Y2 P3 , YP2 , and YP3 ) were identified under compression. Interestingly, as phosphorus content increases, P atoms exhibit diverse behaviors corresponding to standalone anion, dumbbell, zigzag chain, planar sheet, crossing chain-like network, buckled layer, three-dimensional framework, and wrinkled layer. Particularly, Fd-3m YP2 can be viewed as assemblage of diamond-like Y structure and rare vertex-sharing tetrahedral P4  units. Impressively, electron-phonon coupling (EPC) calculations elucidate that Pm-3m Y3 P possesses the highest superconducting critical temperature Tc of 10.2 K among binary transition metal phosphides. Remarkably, the EPC of Pm-3m Y3 P mainly arises from the contribution of low-frequency soft phonon modes, whereas mid-frequency phonon modes of Fd-3m YP2 dominate. These results strengthen knowledge of metal phosphides and pave a way for seeking superconductive transition metal phosphides.

Detection of gadolinium deposition in cortical bone with ultrashort echo time T1 mapping: an ex vivo study in a rabbit model.

OBJECTIVES: To investigate the capacity of ultrashort echo time (UTE) T1 mapping to non-invasively assess gadolinium deposition in cortical bone after gadolinium-based contrast agent (GBCA) administration. METHODS: Twenty-eight New Zealand rabbits (male, 3.0-3.5 kg) were randomly allocated into control, macrocyclic, high-dose macrocyclic, and linear GBCA groups (n = 7 for each group), and respectively given daily doses of 0.9 ml/kg bodyweight saline, 0.3 mmol/kg bodyweight gadobutrol, 0.9 mmol/kg bodyweight gadobutrol, and 0.3 mmol/kg bodyweight gadopentetate dimeglumine for five consecutive days per week over a period of 4 weeks. After a subsequent 4 weeks of recovery, the rabbits were sacrificed and their tibiae harvested. T1 value of cortical bone was measured using a combination of UTE actual flip angle imaging and variable repetition time on a 7T animal scanner. Gadolinium concentration in cortical bone was measured using inductively coupled plasma mass spectrometry (ICP-MS). Pearson's correlation between R1 value (R1 = 1/T1) and gadolinium concentration in cortical bone was assessed. RESULTS: Bone T1 values were significantly lower in the lower-dose macrocyclic (329.2 ± 21.0 ms, p < 0.05), higher-dose macrocyclic (316.8 ± 21.7 ms, p < 0.01), and linear (296.8 ± 24.1 ms, p < 0.001) GBCA groups compared with the control group (356.3 ± 19.4 ms). Gadolinium concentrations measured by ICP-MS in the control, lower-dose macrocyclic, higher-dose macrocyclic, and linear GBCA groups were 0.04 ± 0.02 µg/g, 2.60 ± 0.48 µg/g, 4.95 ± 1.17 µg/g, and 13.62 ± 1.55 µg/g, respectively. There was a strong positive correlation between R1 values and gadolinium concentrations in cortical bone (r = 0.73, p < 0.001). CONCLUSIONS: These results suggest that UTE T1 mapping has the potential to provide a non-invasive assessment of gadolinium deposition in cortical bone following GBCA administration. KEY POINTS: • Changes in T1 value related to gadolinium deposition were found in bone after both linear and macrocyclic GBCA administrations. • R1 relaxometry correlates strongly with gadolinium concentration in cortical bone. • UTE T1 mapping provides a potential tool for non-invasively monitoring gadolinium deposition in cortical bone.

Crystal structures and superconductivity of lithium and fluorine implanted gold hydrides under high pressures.

The investigations on gold science have been capturing research interest due to its diverse physical and chemical properties. Gold hydrides in the solid state, as a member of the Au compound family, are rare since the reaction of Au with H is hindered in terms of their similar electronegativity. It is expected that Li and F can provide electrons and holes, respectively, to help stabilize gold hydrides under high pressure. Herein, by means of a crystal structural search based on particle swarm optimization methodology accompanied by first-principles calculations, four hitherto unknown Li-Au-H compounds (i.e., LiAuH, LiAu2H, Li2Au2H, and Li6AuH) are predicted to be stable under compression. Intriguingly, Au-H bonding is found in LiAuH, LiAu2H, and Li2Au2H. As the gold content increases, Au atom arrangements exhibit diverse forms, from the chain in Li6AuH, the square layer in LiAuH, the network in Li2Au2H, and eventually to the coexistence of square and pyramid layers in LiAu2H. Additionally, Li6AuH has a unique cage-type lithium structure. Furthermore, electron-phonon coupling calculations show that these Li-Au-H phases are phonon-modulated superconductors with a superconducting critical temperature of 1.3, 0.06, and 0.02 K at 25 GPa and 2.79 K at 100 GPa. In contrast, we also identified two solid F4AuH and F6AuH phases with unexpected semiconductivity. They have structural configurations of H-bridged AuF4 quasi-square components and distorted AuF6 octahedrons, respectively, and have no gold-to-hydrogen bonds. Our current results indicate that electron doping at suitable concentrations under pressure can stabilize unique gold hydrides, and provide deep insights into the structures, electron properties, bonding behavior, and stability mechanism of ternary Li-Au-H and F-Au-H compounds.

A Cascaded Model Based on EfficientDet and YOLACT++ for Instance Segmentation of Cow Collar ID Tag in an Image.

In recent years, many imaging systems have been developed to monitor the physiological and behavioral status of dairy cows. However, most of these systems do not have the ability to identify individual cows because the systems need to cooperate with radio frequency identification (RFID) to collect information about individual animals. The distance at which RFID can identify a target is limited, and matching the identified targets in a scenario of multitarget images is difficult. To solve the above problems, we constructed a cascaded method based on cascaded deep learning models, to detect and segment a cow collar ID tag in an image. First, EfficientDet-D4 was used to detect the ID tag area of the image, and then, YOLACT++ was used to segment the area of the tag to realize the accurate segmentation of the ID tag when the collar area accounts for a small proportion of the image. In total, 938 and 406 images of cows with collar ID tags, which were collected at Coldstream Research Dairy Farm, University of Kentucky, USA, in August 2016, were used to train and test the two models, respectively. The results showed that the average precision of the EfficientDet-D4 model reached 96.5% when the intersection over union (IoU) was set to 0.5, and the average precision of the YOLACT++ model reached 100% when the IoU was set to 0.75. The overall accuracy of the cascaded model was 96.5%, and the processing time of a single frame image was 1.92 s. The performance of the cascaded model proposed in this paper is better than that of the common instance segmentation models, and it is robust to changes in brightness, deformation, and interference around the tag.

MRI Gibbs-ringing artifact reduction by means of machine learning using convolutional neural networks.

PURPOSE: To develop a machine learning approach using convolutional neural network for reducing MRI Gibbs-ringing artifact. THEORY AND METHODS: Gibbs-ringing artifact in MR images is caused by insufficient sampling of the high frequency data. Existing methods exploit smooth constraints to reduce intensity oscillations near sharp edges at the cost of blurring details. In this work, we developed a machine learning approach for removing the Gibbs-ringing artifact from MR images. The ringing artifact was extracted from the original image using a deep convolutional neural network and then subtracted from the original image to obtain the artifact-free image. Finally, its low-frequency k-space data were replaced with measured counterparts to enforce data fidelity further. We trained the convolutional neural network using 17,532 T2-weighted (T2W) normal brain images and evaluated its performance on T2W images of normal and tumor brains, diffusion-weighted brain images, and T2W knee images. RESULTS: The proposed method effectively removed the ringing artifact without noticeable smoothing in T2W and diffusion-weighted images. Quantitatively, images produced by the proposed method were closer to the fully-sampled reference images in terms of the root-mean-square error, peak signal-to-noise ratio, and structural similarity index, compared with current state-of-the-art methods. CONCLUSION: The proposed method presents a novel and effective approach for Gibbs-ringing reduction in MRI. The convolutional neural network-based approach is simple, computationally efficient, and highly applicable in routine clinical MRI.

SIRT1 exerts protective effects by inhibiting endoplasmic reticulum stress and NF-κB signaling pathways.

Silent information regulator two homolog 1 (SIRT1), an NAD + -dependent histone deacetylase, plays a pivotal regulatory role in a myriad of physiological processes. A growing body of evidence suggests that SIRT1 can exert protective effects in metabolic disorders and neurodegenerative diseases by inhibiting endoplasmic reticulum (ER) stress and the nuclear factor-κB (NF-κB) inflammatory signaling pathway. This review systematically elucidates the molecular mechanisms and biological significance of SIRT1 in regulating ER stress and the NF-κB pathway. On one hand, SIRT1 can deacetylate key molecules in the ER stress pathway, such as glucose-regulated protein 78 (GRP78), X-box binding protein 1 (XBP1), PKR-like ER kinase (PERK), inositol-requiring enzyme 1α (IRE1α), and activating transcription factor 6 (ATF6), thereby alleviating ER stress. On the other hand, SIRT1 can directly or indirectly remove the acetylation modification of the NF-κB p65 subunit, inhibiting its transcriptional activity and thus attenuating inflammatory responses. Through these mechanisms, SIRT1 can ameliorate insulin resistance in metabolic diseases, exert cardioprotective effects in ischemia-reperfusion injury, and reduce neuronal damage in neurodegenerative diseases. However, it is important to note that while these findings are promising, the complex nature of the biological systems involved warrants further investigation to fully unravel the intricacies of SIRT1's regulatory mechanisms. Nevertheless, understanding the regulatory mechanisms of SIRT1 on ER stress and the NF-κB pathway is of great significance for expanding our knowledge of the pathogenesis of related diseases and exploring new preventive and therapeutic strategies targeting SIRT1.

Construction of phenolic acids grafted chitosan bioactive microspheres to reduce oxidation and iron absorption in meat digestion.

Although iron in meat is an important trace element for human diet, its presence also induces postprandial oxidative stress and aggravates the condition of patients with iron overload. To overcome this situation, a type of new tunable Fe-absorption bioactive materials was constructed in this study. First, four phenolic acids (Caffeic acid, Gallic acid, Protocatechuic acid, Chlorogenic acid) were grafted onto chitosan. Then, the copolymers were prepared into micron-level microspheres by emulsification method, which were characterized in adsorption isotherms (Langmuir model), swelling behavior and digestion characteristics. In order to verify the practical application effect of microspheres, Protocatechuic acid grafted chitosan microspheres as the representative were used in sirloin powder to observe their effects in vitro digestion and rat experiment. In the present study, microspheres were innovatively applied in meat consumption, which significantly inhibited the oxidation of meat in the process of digestion and effectively controlled the iron absorption. These results are expected to play an important role in promoting the healthy consumption of meat around the world, improving gastrointestinal redox status through dietary assistance, and treating diseases related to iron overload.