Neural Radiance Field-Inspired Depth Map Refinement for Accurate Multi-View Stereo.

In this paper, we propose a method to refine the depth maps obtained by Multi-View Stereo (MVS) through iterative optimization of the Neural Radiance Field (NeRF). MVS accurately estimates the depths on object surfaces, and NeRF accurately estimates the depths at object boundaries. The key ideas of the proposed method are to combine MVS and NeRF to utilize the advantages of both in depth map estimation and to use NeRF for depth map refinement. We also introduce a Huber loss into the NeRF optimization to improve the accuracy of the depth map refinement, where the Huber loss reduces the estimation error in the radiance fields by placing constraints on errors larger than a threshold. Through a set of experiments using the Redwood-3dscan dataset and the DTU dataset, which are public datasets consisting of multi-view images, we demonstrate the effectiveness of the proposed method compared to conventional methods: COLMAP, NeRF, and DS-NeRF.

Pose Estimation of Ultrasound Probe Using CNN and RNN with Image Reconstruction Loss.

It is necessary to estimate the pose of the probe with high accuracy to reconstruct 3D ultrasound (US) images only from US image sequences scanned by a 1D-array probe. We propose the probe pose estimation method using Convolutional Neural Network (CNN) with training by image reconstruction loss. To calculate the image reconstruction loss, we use the image reconstruction network which consists of an encoder that extracts features from the two US images and a decoder that reconstructs the intermediate US image between the two images. CNN is trained to minimize the image reconstruction loss between the ground-truth image and the reconstructed image. Through experiments, we demonstrate that the proposed method exhibits efficient performance compared with the conventional methods.

Antidepressant properties of voluntary exercise mediated by gut microbiota.

Although regular exercise has been reported to prevent depression, it has not been clarified whether the gut microbiota is involved in the factors that prevent depression through exercise. We investigated the effects of voluntary exercise on the gut microbiota and the prevention of depression-like behaviors using mice. C57BL/6 J male mice were subjected to 10 weeks of sedentary control or wheel running, then they were subjected to social defeat stress (SDS). Exercise attenuated that sucrose drinking was decreased by SDS treatment. Exercise increased the expression of Bdnf and decreased expression of Zo-1 and Claudin5 in the brain. Fecal Turicibacter, Allobaculum, and Clostridium sensu stricto, and propionate in the cecum were decreased by the exercise. Voluntary exercise-induced antidepressant properties might be partially caused by suppression of serotonin uptake into gut microbiota and increase the permeability of the blood-brain barrier via reduced propionate production.

Acetyl-L-carnitine attenuates Poly I:C-induced sickness behavior in mice.

Fatigue is accompanied by a decrease in physical activity or malaise, and might be reduced by acetyl-L-carnitine (ALC) administration. The purpose of this study was to investigate the preventive effects of ALC on Poly I:C-induced sickness behavior in mice. For the experiment, male C3H/HeN mice were used and treated with ALC for 5 days before Poly I:C administration. ALC administration attenuated the decrease in wheel behavior activity of mice at 24 h after Poly I:C administration and ALC-treated mice quickly recovered from the sickness behavior. The gene expression of brain-derived neurotrophic factor (BDNF) in the cerebrum and hippocampus, which is associated with physical activity, was higher in the ALC-treated group. Translocator protein 18kDa (TSPO), which has cytoprotective effects, was up-regulated in the cerebrum and hippocampus, suggesting that ALC suppressed the decrease in activity induced by Poly I:C treatment through enhancement of cytoprotective effects in the brain.

LPS-induced TNF-α production is attenuated by intake with PHGG via gut microbial fermentation in mice.

OBJECTIVES: Intake of dietary fibers promotes the production of short-chain fatty acids (SCFAs), which can affect host inflammation via gut microbial fermentation. Although partially hydrolyzed guar-gum (PHGG) is a water-soluble dietary fiber with lower viscosity, its benefits in acute inflammation are yet to be determined. The aim of this study was to investigate the effect of PHGG intake on the lipopolysaccharide (LPS)-induced tumor necrosis factor (TNF)-α production. METHODS: Nine-wk-old male C3 H/HeN mice were used in this study, and they were randomly divided into control diet (CD) and CD + 5% PHGG (GGCD) groups. After a dietary intervention of 6 wk, LPS (1 mg/kg) was injected into the orbital vein. Plasma TNF-α concentration and SCFAs in cecum contents were then measured. Also, the effect of gut microbiota on LPS-induced TNF-α production was evaluated in PHGG-fed mice before and after antibiotic treatment. RESULTS: PHGG intake accelerated a dramatic suppression of LPS-induced TNF-α production (P < 0.01). PHGG-induced low pH in feces (P < 0.05) indicates that the gut microbiota induced high fermentation. Indeed, SCFAs in cecum contents of GGCD mice were significantly higher than in the CD group (P < 0.05). Furthermore, PHGG intake after antibiotic treatment did not induce the suppression of TNF-α. CONCLUSION: These results demonstrated that inflammation was inhibited by habitual PHGG ingestion, suggesting that this phenomenon might be associated with changes in gut microbiota-induced SCFAs production.

Face Attribute Estimation Using Multi-Task Convolutional Neural Network.

Face attribute estimation can be used for improving the accuracy of face recognition, customer analysis in marketing, image retrieval, video surveillance, and criminal investigation. The major methods for face attribute estimation are based on Convolutional Neural Networks (CNNs) that solve face attribute estimation as a multiple two-class classification problem. Although one feature extractor should be used for each attribute to explore the accuracy of attribute estimation, in most cases, one feature extractor is shared to estimate all face attributes for the parameter efficiency. This paper proposes a face attribute estimation method using Merged Multi-CNN (MM-CNN) to automatically optimize CNN structures for solving multiple binary classification problems to improve parameter efficiency and accuracy in face attribute estimation. We also propose a parameter reduction method called Convolutionalization for Parameter Reduction (CPR), which removes all fully connected layers from MM-CNNs. Through a set of experiments using the CelebA and LFW-a datasets, we demonstrate that MM-CNN with CPR exhibits higher efficiency of face attribute estimation in terms of estimation accuracy and the number of weight parameters than conventional methods.

Perfusion defects in non-enlarged metastatic lymph nodes using vessel wall magnetic resonance imaging: Detection performance and diagnostic value.

A perfusion defect (PD) in non-enlarged lymph nodes (LNs) of oral squamous cell carcinoma (OSCC) is the most reliable radiological criterion for the diagnosis of metastasis. However, conventional contrast-enhanced (CE) T1 weighted images using turbo spin echo (TSE) sequence is limited in detecting PD in non-enlarged LNs due to flow artifacts from cervical blood vessels. Vessel wall (VW) MR imaging with blood vessel flow suppression and high spatial resolution may provide new insights into the detection of PD. However, there are no reports in the literature on the usefulness of VW MR imaging for the diagnosis of LN metastasis. It is demonstrated that PD of non-enlarged LNs in CE VR MR imaging of OSCC patients is useful for the diagnosis of metastatic LNs. VW MR imaging was significantly more sensitive in detecting PD of non-enlarged metastatic LNs than conventional TSE imaging on visual evaluation. Furthermore, it was found that the image contrast between PD and surrounding intranodal tissue in CE VW MR images was higher than that in conventional CE TSE images. In the correlation between imaging and histopathological findings of metastatic LNs, all LNs that exhibited PD on CE VW MR images were at an advanced histopathological metastatic stage. The pathology of PD was necrotic tissue with keratinization. The results indicated that PD in CE VW imaging is useful in diagnosing non-enlarged LNs at an advanced metastasis stage. The addition of VW MR imaging to conventional MR examination achieves higher diagnostic performance for non-enlarged metastatic LNs.

The Effect of Voluntary Exercise on Gut Microbiota in Partially Hydrolyzed Guar Gum Intake Mice under High-Fat Diet Feeding.

Although dietary fiber treatment alters the gut microbiota and its metabolite production, it is unclear whether or not exercise habits can have a supplemental effect on changes in gut microbiota in dietary fiber-treated mice. To clarify the supplemental effect of voluntary exercise on gut microbiota in partially hydrolyzed guar gum (PHGG), which is a soluble dietary fiber, treated mice under high-fat diet (HFD) feeding, 4-week-old male C57BL/6J mice (n = 80) were randomly divided into two dietary groups: the control-diet (CD) and HFD. Then, each dietary group was treated with or without PHGG, and with or without wheel running. After the experimental period, measurement of maximal oxygen consumption, a glucose tolerance test and fecal materials collection for analysis of gut microbiota were carried out. Voluntary exercise load in PHGG treatment under HFD feeding showed the supplemental effect of exercise on obesity (p < 0.01) and glucose tolerance (p < 0.01). Additionally, in both CD and HFD groups, voluntary exercise accelerated the decrease in the Firmicutes/Bacteroidetes ratio in mice fed with PHGG (p < 0.01). These findings suggest that voluntary exercise might activate the prevention of obesity and insulin resistance more via change in gut microbiota in mice administrated with PHGG.

FSBC: fast string-based clustering for HT-SELEX data.

BACKGROUND: The combination of systematic evolution of ligands by exponential enrichment (SELEX) and deep sequencing is termed high-throughput (HT)-SELEX, which enables searching aptamer candidates from a massive amount of oligonucleotide sequences. A clustering method is an important procedure to identify sequence groups including aptamer candidates for evaluation with experimental analysis. In general, aptamer includes a specific target binding region, which is necessary for binding to the target molecules. The length of the target binding region varies depending on the target molecules and/or binding styles. Currently available clustering methods for HT-SELEX only estimate clusters based on the similarity of full-length sequences or limited length of motifs as target binding regions. Hence, a clustering method considering the target binding region with different lengths is required. Moreover, to handle such huge data and to save sequencing cost, a clustering method with fast calculation from a single round of HT-SELEX data, not multiple rounds, is also preferred. RESULTS: We developed fast string-based clustering (FSBC) for HT-SELEX data. FSBC was designed to estimate clusters by searching various lengths of over-represented strings as target binding regions. FSBC was also designed for fast calculation with search space reduction from a single round, typically the final round, of HT-SELEX data considering imbalanced nucleobases of the aptamer selection process. The calculation time and clustering accuracy of FSBC were compared with those of four conventional clustering methods, FASTAptamer, AptaCluster, APTANI, and AptaTRACE, using HT-SELEX data (>15 million oligonucleotide sequences). FSBC, AptaCluster, and AptaTRACE could complete the clustering for all sequence data, and FSBC and AptaTRACE performed higher clustering accuracy. FSBC showed the highest clustering accuracy and had the second fastest calculation speed among all methods compared. CONCLUSION: FSBC is applicable to a large HT-SELEX dataset, which can facilitate the accurate identification of groups including aptamer candidates. AVAILABILITY OF DATA AND MATERIALS: FSBC is available at http://www.aoki.ecei.tohoku.ac.jp/fsbc/.

Differences in muscle attachment proportion within the most common location of medial tibial stress syndrome in vivo.

INTRODUCTION: The medial tibial stress syndrome is one of the most common causes of running-related injuries. The primary study objective was to observe the attachment proportion of flexor digitorum longus and soleus, at the most common location of medial tibial stress syndrome, using ultrasonography, on a large cohort of young males and females to evaluate for gender-based anatomical differences. The secondary objective of this study was to investigate the relationship between the anatomical features and medial tibial stress syndrome. METHODS: In this study, we observed whether or not flexor digitorum longus and/or soleus attached at the middle and distal thirds of the medial margin of the tibia (most common location of medial tibial stress syndrome) using ultrasonography. History of medial tibial stress syndrome was defined by inquiries. RESULTS: The Chi2 tests showed that the attachment proportion of the soleus in female participants was significantly higher than that observed in male participants. In addition, Chi2 testing showed that there were no significant differences between attachment proportion of soleus of legs with history of medial tibial stress syndrome and legs without history of medial tibial stress syndrome, in both male and female participants. CONCLUSIONS: These results suggested that the anatomical features of flexor digitorum longus might be involved in medial tibial stress syndrome development, whereas the anatomical features of the soleus might not be involved in medial tibial stress syndrome development. LEVEL OF EVIDENCE: III, cross-sectional study.

Effect of Static Stretching with Superficial Cooling on Muscle Stiffness.

This study aimed to clarify the acute effect of static stretching (SS) with superficial cooling on dorsiflexion range of motion (DF ROM) and muscle stiffness. Sixteen healthy males participated in the cooling condition and a control condition in a random order. The DF ROM and the shear elastic modulus of medial gastrocnemius (MG) in the dominant leg were measured during passive dorsiflexion. All measurements were performed prior to (PRE) and immediately after 20 min of cooling or rested for 20 min (POST), followed by 2 min SS (POST SS). In cooling condition, DF ROM at POST and POST SS were significantly higher than that at PRE and DF ROM at POST SS was significantly higher than that at POST. In addition, the shear elastic modulus at POST was significantly higher than that at PRE and the shear elastic modulus at POST SS was significantly lower than those at PRE and POST. However, there were no significant differences in the percentage changes between PRE and POST SS between the cooling and control conditions. Our results showed that effects of SS with superficial cooling on increases in ROM and decrease in muscle stiffness were no more beneficial than those of SS alone.

Performance Evaluation of Age Estimation from T1-Weighted Images Using Brain Local Features and CNN.

The age of a subject can be estimated from the brain MR image by evaluating morphological changes in healthy aging. We consider using two-types of local features to estimate the age from T1-weighted images: handcrafted and automatically extracted features in this paper. The handcrafted brain local features are defined by volumes of brain tissues parcellated into 90 or 1,024 local regions defined by the automated anatomical labeling atlas. The automatically extracted features are obtained by using the convolutional neural network (CNN). This paper explores the difference between the handcrafted features and the automatically extracted features. Through a set of experiments using 1,099 T1-weighted images from a Japanese MR image database, we demonstrate the effectiveness of the proposed methods, analyze the effectiveness of each local region for age estimation and discuss its medical implication.

Reduction of Real-Time Imaging of M1 Macrophage Chemotaxis toward Damaged Muscle Cells is PI3K-Dependent.

Macrophages migrate and invade into damaged muscle rapidly and are important for muscle repair and subsequent regeneration. The exact cellular and biological events that cause macrophage migration toward injured muscle are not completely understood. In this study, the effect of macrophage differentiation on the chemotactic capability to invade local damaged muscle was investigated using an in vitro model of muscle injury. We used C2C12 cell myoblasts and J774 cell macrophages, and the "killed-C2C12" cells were combined with live C2C12 cells as a partially damaged muscle model. The cultured J774 cells, with or without lipopolysaccharide (LPS), were treated with Ly294002 (Ly), which is an inhibitor of phosphoinositide 3-kinase (PI3K). In order to evaluate the polarization effect of LPS stimulation on J774 cells, expression of cell surface Toll-like receptor 4 (TLR4), CD11c and CCR2, and expression of F-actin intensity, were analyzed by flow cytometry. The real-time horizontal chemotaxis assay of J774 cells was tested using the TAXIScan device. The expressions of TLR4, CD11c, and F-actin intensity in LPS-treated cells were significantly higher than those in Ctrl cells. In LPS-treated cells, the chemotactic activity toward damaged muscle cells completely disappeared. Moreover, the reduced chemotaxis depended far more on directionality than velocity. However, Ly treatment reversed the reduced chemotactic activity of the LPS-treated cells. In addition, cell-adhesion and F-actin intensity, but not CCR2 expression, in LPS-treated cells, was significantly reduced by Ly treatment. Taken together, our results suggest that the PI3K/Akt activation state drives migration behavior towards damaged muscle cells.

The effect of a running task on muscle shear elastic modulus of posterior lower leg.

BACKGROUND: Medial tibial stress syndrome (MTSS) is one of the most common causes of exercise-related leg pain in runners. Because stopping training due to pain from MTSS could decrease the athlete's competitiveness, it is necessary to construct MTSS prevention and treatment programs. However, the effect of running, which is believed to cause MTSS, on shear elastic modulus of the posterior lower leg is unclear. Therefore, the purpose of this study was to investigate the effect of 30 min of running on shear elastic modulus of the posterior lower leg in healthy subjects. METHODS: Twenty healthy males volunteered to participate in this study (age, 20.9 ± 0.6 y; height, 169.6 ± 4.5 cm; weight, 62.6 ± 5.2 kg). The shear elastic modulus of the posterior lower leg was measured using ultrasonic shear wave elastography before and immediately after a 30-min running task. RESULTS: Shear elastic moduli of the flexor digitorum longus and tibialis posterior were significantly increased after 30 min running task. However, there were no significant changes in shear elastic moduli of the lateral gastrocnemius, medial gastrocnemius, peroneus longus and peroneus brevis. CONCLUSION: The results suggested that the increases in shear elastic moduli of flexor digitorum longus and tibialis posterior after running could be a risk factor for running-related MTSS development.

Brain age estimation from T1-weighted images using effective local features.

Statistical analysis using large-scale brain magnetic resonance (MR) image databases has examined that brain tissues have age-related morphological changes. The age of a subject can be estimated from the brain MR image by evaluating morphological changes with healthy aging. This paper proposes an age estimation method using local features of T1-weighted MR images. The brain local features are defined by volumes of brain tissues parcellated into 1,024 local regions defined by the automated anatomical labeling atlas. This paper also proposes the effective local feature selection method to improve the accuracy of age estimation. We evaluate the accuracy of the proposed method using 1,099 T1-weighted images from a Japanese MR image database. We also analyze effectiveness of each local region for age estimation and discuss its medical implication.

Responsiveness of the Self-Administered Foot Evaluation Questionnaire (SAFE-Q) in patients with hallux valgus.

BACKGROUND: In this study, we investigated the responsiveness of the Self-Administered Foot Evaluation Questionnaire (SAFE-Q) for patient's assessment before and after hallux valgus surgery. METHODS: Patient-reported answers on the SAFE-Q and Short Form-36 (SF-36) before and at a mean of 3-4 and 9-12 months after hallux valgus surgery were analyzed. Data of 100 patients (92 women, eight men) from 36 institutions throughout Japan were used for analysis. RESULTS: In all subscales of the SAFE-Q, the trend of increased scores after surgery was statistically significant (P < 0.001). Among the patients with available scores both before and at 9-12 months after surgery (n = 66), the largest effect sizes (ESs) were observed for shoe-related (1.60), pain and pain-related (1.05), and general health and well-being (0.84) scales. In the SF-36 (n = 64), the largest ES was observed for the bodily pain scale (0.86). Less notable changes were observed for the remaining SF-36 domains. CONCLUSION: The SAFE-Q is the first patient-reported outcome measure which includes a quality of life assessment of shoes. In our cohort, the most remarkable responsiveness was observed for the shoe-related subscale. Based on its responsiveness, the SAFE-Q appears to be sufficient for evaluation of foot-related quality of life before and after surgery.

Aichi cohort study of the prognosis in patients newly initiated into dialysis (AICOPP): baseline characteristics and trends observed in diabetic nephropathy.

BACKGROUND: Over 300,000 patients receive maintenance dialysis in Japan; managing these patients is extremely important. This study aimed to report on prior management of chronic kidney diseases and prognostication after dialysis initiation. PATIENTS AND METHODS: Seventeen institutions participated in the Aichi cohort study of prognosis in patients newly initiated into dialysis and recruited patients over a period of 2 years. Exclusion criteria were (1) patients under 20 years; (2) patients who died before hospital discharge; and (3) patients who could not provide consent. RESULT: Here, we showed data on dialysis initiation time. Of 1524 patients with mean age of 67.5 ± 13.0 years, 659 patients were put on dialysis following diabetic nephropathy diagnosis. At dialysis initiation time, creatinine and estimated glomerular filtration rate levels were 8.97 ± 3.21 mg/dl and 5.45 ± 2.22 ml/min/1.73 m2, respectively. Medications taken were angiotensin II receptor blockers in 866; angiotensin-converting enzyme inhibitors in 135; calcium antagonist in 1202; and diuretics, alone or in combination, in 1059. Among patients with diabetic nephropathy, many had increased body weight and systolic blood pressure and were taking loop and thiazide diuretics at dialysis initiation time. Many patients with diabetic nephropathy had coronary artery disease and percutaneous coronary intervention. CONCLUSION: Many patients with diabetic nephropathy who registered for this study had coronary artery disease and problems with excess body fluid. Further analyses may clarify how underlying conditions and disease management before and after dialysis initiation affect prognosis.

Age estimation using effective brain local features from T1-weighted images.

This paper proposes a simple method of selecting effective brain local features for age estimation from T1-weighted MR images. We also employ the high-resolution AAL atlas, which is defined by 1,024 local regions, to improve the accuracy of age estimation. We evaluate performance of the proposed method using 1,099 T1-weighted images from a large-scale brain MR image database of healthy Japanese, and demonstrate that the proposed method exhibits efficient performance of age estimation compared with conventional methods.

High-Accuracy Ultrasound Contrast Agent Detection Method for Diagnostic Ultrasound Imaging Systems.

An accurate method for detecting contrast agents using diagnostic ultrasound imaging systems is proposed. Contrast agents, such as microbubbles, passing through a blood vessel during ultrasound imaging are detected as blinking signals in the temporal axis, because their intensity value is constantly in motion. Ultrasound contrast agents are detected by evaluating the intensity variation of a pixel in the temporal axis. Conventional methods are based on simple subtraction of ultrasound images to detect ultrasound contrast agents. Even if the subject moves only slightly, a conventional detection method will introduce significant error. In contrast, the proposed technique employs spatiotemporal analysis of the pixel intensity variation over several frames. Experiments visualizing blood vessels in the mouse tail illustrated that the proposed method performs efficiently compared with conventional approaches. We also report that the new technique is useful for observing temporal changes in microvessel density in subiliac lymph nodes containing tumors. The results are compared with those of contrast-enhanced computed tomography.

Two brothers with collagenofibrotic glomerulopathy.

Collagenofibrotic glomerulopathy is a rare glomerular disease characterized by extensive accumulation of atypical type III collagen fibers within the mesangial matrix and subendothelial space. Laboratory evaluation of this disease shows a marked increase in serum procollagen III peptide (P III P) levels. Here, we report the case of two brothers with collagenofibrotic glomerulopathy confirmed by histology. Patient 1 presented with proteinuria and hypertension and patient 2 presented with nephrotic-range proteinuria. Immunohistochemistry revealed strong staining for antibodies to type III collagen in the widened subendothelial spaces in both patients. Electron microscopy revealed numerous collagenous fibers in the mesangium and subendothelial space. P III P levels were elevated in both patients. Most reported cases of collagenofibrotic glomerulopathy, including the adult-onset type, have been sporadic. Within the limits of our literature search, this is only the third report of adult siblings with collagenofibrotic glomerulopathy confirmed by histology. This report indicates that it may be beneficial to measure serum P III P levels in the siblings of patients diagnosed with adult-onset collagenofibrotic glomerulopathy.