Experimental measurement of quadrature squeezing in quadripartite entanglement.

Multipartite entanglement is one of the most fundamental and important resources for quantum information processing in both discrete variable and continuous variable (CV) regimes. For its applications in the CV regime, such as the realization of quantum teleportation networks and quantum dense coding, the quadrature squeezing of multipartite entanglement plays a significant role. Here, we report the first, to the best of our knowledge, experimental measurement of the quadrature squeezing in the quadripartite entanglement generated by the two-beam pumped cascaded four-wave mixing process in a 85 R b vapor cell. Moreover, we find that the quadrature squeezing is nonexistent in each pair of beams, but exists in the whole quadripartite entanglement. Our results may find potential applications in building a multi-user quantum secret sharing network.

Toward More Accessible Fully Automated 3D Volumetric MRI Decision Trees for the Differential Diagnosis of Multiple System Atrophy, Related Disorders, and Age-Matched Healthy Subjects.

Differentiating multiple system atrophy (MSA) from related neurodegenerative movement disorders (NMD) is challenging. MRI is widely available and automated decision-tree analysis is simple, transparent, and resistant to overfitting. Using a retrospective cohort of heterogeneous clinical MRIs broadly sourced from a tertiary hospital system, we aimed to develop readily translatable and fully automated volumetric diagnostic decision-trees to facilitate early and accurate differential diagnosis of NMDs. 3DT1 MRI from 171 NMD patients (72 MSA, 49 PSP, 50 PD) and 171 matched healthy subjects were automatically segmented using Freesurfer6.0 with brainstem module. Decision trees employing substructure volumes and a novel volumetric pons-to-midbrain ratio (3D-PMR) were produced and tenfold cross-validation performed. The optimal tree separating NMD from healthy subjects selected cerebellar white matter, thalamus, putamen, striatum, and midbrain volumes as nodes. Its sensitivity was 84%, specificity 94%, accuracy 84%, and kappa 0.69 in cross-validation. The optimal tree restricted to NMD patients selected 3D-PMR, thalamus, superior cerebellar peduncle (SCP), midbrain, pons, and putamen as nodes. It yielded sensitivities/specificities of 94/84% for MSA, 72/96% for PSP, and 73/92% PD, with 79% accuracy and 0.62 kappa. There was correct classification of 16/17 MSA, 5/8 PSP, 6/8 PD autopsy-confirmed patients, and 6/8 MRIs that preceded motor symptom onset. Fully automated decision trees utilizing volumetric MRI data distinguished NMD patients from healthy subjects and MSA from other NMDs with promising accuracy, including autopsy-confirmed and pre-symptomatic subsets. Our open-source methodology is well-suited for widespread clinical translation. Assessment in even more heterogeneous retrospective and prospective cohorts is indicated.

Development and autoregulation of kidney function in children: a retrospective study using 99mTc-MAG3 renography.

BACKGROUND: Both the development of kidney function in healthy children and autoregulation ability of kidney function in patients with asymmetric kidneys are important in clinical diagnosis and treatment of kidney-related diseases, but there are however only limited studies. This study aimed to investigate development of kidney function in normal children with healthy symmetric kidneys and autoregulation of the healthy kidney compensating the functional loss of a diseased one in children with asymmetric kidneys. METHODS: Two hundred thirty-seven children (156 male, 81 female) from 0 to 20y (average 4.6y ± 5.1) undergoing 99mTc-MAG3 renography were included, comprising 134 with healthy symmetrically functioning kidneys and 103 with asymmetric kidneys. Clearance was calculated from kidney uptakes at 1-2 min. A developmental model between MAG3 clearance (CL) and patient age in normal group was identified (CL = 84.39Age0.395 ml/min, r = 0.957, p < 0.001). The clearance autoregulation rate in abnormal group with asymmetric kidneys was defined as the ratio of the measured MAG3 clearance and the normal value predicted from the renal developmental model of normal group. RESULTS: No significant difference of MAG3 clearance (p = 0.723) was found between independent abnormal group and normal group. The autoregulation rate of kidney clearance in abnormal group was 94.2% on average, and no significant differences were found between two age groups (p = 0.49), male and female (p = 0.39), and left kidney and right kidney (p = 0.92) but two different grades of asymmetric kidneys (p = 0.02). CONCLUSIONS: The healthy kidney of two asymmetric kidneys can automatically regulate total kidney function up to 94% of two symmetric kidneys in normal children.

A New Framework of Designing Iterative Techniques for Image Deblurring.

In this work we present a framework of designing iterative techniques for image deblurring in inverse problem. The new framework is based on two observations about existing methods. We used Landweber method as the basis to develop and present the new framework but note that the framework is applicable to other iterative techniques. First, we observed that the iterative steps of Landweber method consist of a constant term, which is a low-pass filtered version of the already blurry observation. We proposed a modification to use the observed image directly. Second, we observed that Landweber method uses an estimate of the true image as the starting point. This estimate, however, does not get updated over iterations. We proposed a modification that updates this estimate as the iterative process progresses. We integrated the two modifications into one framework of iteratively deblurring images. Finally, we tested the new method and compared its performance with several existing techniques, including Landweber method, Van Cittert method, GMRES (generalized minimal residual method), and LSQR (least square), to demonstrate its superior performance in image deblurring.

3D printed scaffold for repairing bone defects in apical periodontitis.

OBJECTIVES: To investigate the feasibility of the 3D printed scaffold for periapical bone defects. METHODS: In this study, antimicrobial peptide KSL-W-loaded PLGA sustainable-release microspheres (KSL-W@PLGA) were firstly prepared followed by assessing the drug release behavior and bacteriostatic ability against Enterococcus faecalis and Porphyromonas gingivalis. After that, we demonstrated that KSL-W@PLGA/collagen (COL)/silk fibroin (SF)/nano-hydroxyapatite (nHA) (COL/SF/nHA) scaffold via 3D-printing technique exhibited significantly good biocompatibility and osteoconductive property. The scaffold was characterized as to pore size, porosity, water absorption expansion rate and mechanical properties. Moreover, MC3T3-E1 cells were seeded into sterile scaffold materials and investigated by CCK-8, SEM and HE staining. In the animal experiment section, we constructed bone defect models of the mandible and evaluated its effect on bone formation. The Japanese white rabbits were killed at 1 and 2 months after surgery, the cone beam computerized tomography (CBCT) and micro-CT scanning, as well as HE and Masson staining analysis were performed on the samples of the operation area, respectively. Data analysis was done using ANOVA and LSD tests. (α = 0.05). RESULTS: We observed that the KSL-W@PLGA sustainable-release microspheres prepared in the experiment were uniform in morphology and could gradually release the antimicrobial peptide (KSL-W), which had a long-term antibacterial effect for at least up to 10 days. HE staining and SEM showed that the scaffold had good biocompatibility, which was conducive to the adhesion and proliferation of MC3T3-E1 cells. The porosity and water absorption of the scaffold were (81.96 ± 1.83)% and (458.29 ± 29.79)%, respectively. Histological and radiographic studies showed that the bone healing efficacy of the scaffold was satisfactory. CONCLUSIONS: The KSL-W@PLGA/COL/SF/nHA scaffold possessed good biocompatibility and bone repairing ability, and had potential applications in repairing infected bone defects. Clinical significance The 3D printed scaffold not only has an antibacterial effect, but can also promote bone tissue formation, which provides an alternative therapy option in apical periodontitis.

Microbial ecology in selenate-reducing biofilm communities: Rare biosphere and their interactions with abundant phylotypes.

Selenate (SeO42- ) reduction in hydrogen (H2 )-fed membrane biofilm reactors (H2 -MBfRs) was studied in combinations with other common electron acceptors. We employed H2 -MBfRs with two distinctly different conditions: R1, with ample electron-donor availability and acceptors SeO42- and sulfate (SO42- ), and R2, with electron-donor limitation and the presence of electron acceptors SeO42- , nitrate (NO3- ), and SO42- . Even though H2 was available to reduce all input SeO42- and SO42- in R1, SeO42- reduction was preferred over SO42- reduction. In R2, co-reduction of NO3- and SeO42- occurred, and SO42- reduction was mostly suppressed. Biofilms in all MBfRs had high microbial diversity that was influenced by the "rare biosphere" (RB), phylotypes with relative abundance less than 1%. While all MBfR biofilms had abundant members, such as Dechloromonas and Methyloversatilis, the bacterial communities were significantly different between R1 and R2. For R1, abundant genera were Methyloversatilis, Melioribacter, and Propionivibrio; for R2, abundant genera were Dechloromonas, Hydrogenophaga, Cystobacter, Methyloversatilis, and Thauera. Although changes in electron-acceptor or -donor loading altered the phylogenetic structure of the microbial communities, the biofilm communities were resilient in terms of SeO42- and NO3- reductions, because interacting members of the RB had the capacity of respiring these electron acceptors.

Schisandrin B Protects against Acute Ethanol-Induced Cardiac Injury by Downregulating Autophagy via the NOX4/ROS Pathway.

INTRODUCTION: Although oxidative stress has been demonstrated to mediate acute ethanol-induced changes in autophagy in the heart, the precise mechanism behind redox regulation in acute ethanol heart disease remains largely unknown. METHODS: Wild-type C57BL/6 mice were intraperitoneally injected with ethanol (3 g/kg/day) for 3 consecutive days. The effects of ethanol on cultured primary cardiomyocytes and H9c2 myoblasts were also studied in vitro. Levels of autophagic flux, cardiac apoptosis and function, reactive oxygen species (ROS) accumulation, NOX4, and NOX2 were examined. The NOX4 gene was knocked down with NOX4 siRNA. RESULTS: In this study, we demonstrated that schisandrin B inhibited acute ethanol-induced autophagy and sequent apoptosis. In addition, schisandrin B treatment improved cardiac function in ethanol-treated mice. Furthermore, NOX4 protein expression was increased during acute ethanol exposure, and the upregulation of NOX4 was significantly inhibited by schisandrin B treatment. The knockdown of NOX4 prevented ROS accumulation, cell autophagy, and apoptosis. CONCLUSION: These results highlight that NOX4 is a critical mediator of ROS and elaborate the role of the NOX4/ROS axis in the effect of schisandrin B on autophagy and autophagy-mediated apoptosis in acute ethanol exposure, which suggests a therapeutic strategy for acute alcoholic cardiomyopathy.

Serum Metabolomics Reveals Personalized Metabolic Patterns for Macular Neovascular Disease Patient Stratification.

The macular neovascular disease is a group disorder with complex pathogenesis of neovascularization for vision impairment and irreversible blindness, posing great challenges to precise diagnosis and management. We prospectively recruited participants with age-related macular degeneration (AMD), polypoidal choroidal vasculopathy (PCV), and pathological myopia (PM) and compared with cataract patients without fundus diseases as a control group. The serum metabolome was profiled by gas chromatography coupled with time-of-flight mass spectrometry (GC-TOFMS) analysis. Multivariate statistical methods as well as data mining were performed for interpretation of macular neovascularization. A total of 446 participants with macular neovascularization and 138 cataract subjects as the control group were enrolled in this study. By employing GC-TOFMS, 131 metabolites were identified and 33 differentiating metabolites were highlighted in patients with macular neovascularization. For differential diagnosis, three panels of specific metabolomics-based biomarkers provided areas under the curve of 0.967, 0.938, and 0.877 in the discovery phase (n = 328) and predictive values of 87.3%, 79%, and 85.7% in the test phase (n = 256). Personalized pathway dysregulation scores measurement using Lilikoi package in R language revealed the pentose phosphate pathway and mitochondrial electron transport chain as the most important pathways in AMD; purine metabolism and glycolysis were identified as the major disturbed pathways in PCV, while the altered thiamine metabolism and purine metabolism may contribute to PM phenotypes. Serum metabolomics are powerful for characterizing metabolic disturbances of the macular neovascular disease. Differences in metabolic pathways may reflect an underlying macular neovascular disease and serve as therapeutic targets for macular neovascular treatment.

Deep-Learning Detection of Cancer Metastases to the Brain on MRI.

BACKGROUND: Approximately one-fourth of all cancer metastases are found in the brain. MRI is the primary technique for detection of brain metastasis, planning of radiotherapy, and the monitoring of treatment response. Progress in tumor treatment now requires detection of new or growing metastases at the small subcentimeter size, when these therapies are most effective. PURPOSE: To develop a deep-learning-based approach for finding brain metastasis on MRI. STUDY TYPE: Retrospective. SEQUENCE: Axial postcontrast 3D T1 -weighted imaging. FIELD STRENGTH: 1.5T and 3T. POPULATION: A total of 361 scans of 121 patients were used to train and test the Faster region-based convolutional neural network (Faster R-CNN): 1565 lesions in 270 scans of 73 patients for training; 488 lesions in 91 scans of 48 patients for testing. From the 48 outputs of Faster R-CNN, 212 lesions in 46 scans of 18 patients were used for training the RUSBoost algorithm (MatLab) and 276 lesions in 45 scans of 30 patients for testing. ASSESSMENT: Two radiologists diagnosed and supervised annotation of metastases on brain MRI as ground truth. This data were used to produce a 2-step pipeline consisting of a Faster R-CNN for detecting abnormal hyperintensity that may represent brain metastasis and a RUSBoost classifier to reduce the number of false-positive foci detected. STATISTICAL TESTS: The performance of the algorithm was evaluated by using sensitivity, false-positive rate, and receiver's operating characteristic (ROC) curves. The detection performance was assessed both per-metastases and per-slice. RESULTS: Testing on held-out brain MRI data demonstrated 96% sensitivity and 20 false-positive metastases per scan. The results showed an 87.1% sensitivity and 0.24 false-positive metastases per slice. The area under the ROC curve was 0.79. CONCLUSION: Our results showed that deep-learning-based computer-aided detection (CAD) had the potential of detecting brain metastases with high sensitivity and reasonable specificity. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 2 J. Magn. Reson. Imaging 2020;52:1227-1236.

Integrated bioinformatics analysis of aberrantly-methylated differentially-expressed genes and pathways in age-related macular degeneration.

BACKGROUND: Age-related macular degeneration (AMD) represents the leading cause of visual impairment in the aging population. The goal of this study was to identify aberrantly-methylated, differentially-expressed genes (MDEGs) in AMD and explore the involved pathways via integrated bioinformatics analysis. METHODS: Data from expression profile GSE29801 and methylation profile GSE102952 were obtained from the Gene Expression Omnibus database. We analyzed differentially-methylated genes and differentially-expressed genes using R software. Functional enrichment and protein-protein interaction (PPI) network analysis were performed using the R package and Search Tool for the Retrieval of Interacting Genes online database. Hub genes were identified using Cytoscape. RESULTS: In total, 827 and 592 genes showed high and low expression, respectively, in GSE29801; 4117 hyper-methylated genes and 511 hypo-methylated genes were detected in GSE102952. Based on overlap, we categorized 153 genes as hyper-methylated, low-expression genes (Hyper-LGs) and 24 genes as hypo-methylated, high-expression genes (Hypo-HGs). Four Hyper-LGs (CKB, PPP3CA, TGFB2, SOCS2) overlapped with AMD risk genes in the Public Health Genomics and Precision Health Knowledge Base. KEGG pathway enrichment analysis indicated that Hypo-HGs were enriched in the calcium signaling pathway, whereas Hyper-LGs were enriched in sphingolipid metabolism. In GO analysis, Hypo-HGs were enriched in fibroblast migration, membrane raft, and coenzyme binding, among others. Hyper-LGs were enriched in mRNA transport, nuclear speck, and DNA binding, among others. In PPI network analysis, 23 nodes and two edges were established from Hypo-HGs, and 151 nodes and 73 edges were established from Hyper-LGs. Hub genes (DHX9, MAPT, PAX6) showed the greatest overlap. CONCLUSION: This study revealed potentially aberrantly MDEGs and pathways in AMD, which might improve the understanding of this disease.

Insights into selenate removal mechanism of hydrogen-based membrane biofilm reactor for nitrate-polluted groundwater treatment based on anaerobic biofilm analysis.

The selenate removal mechanism of hydrogen-based membrane biofilm reactor (MBfR) for nitrate-polluted groundwater treatment was studied based on anaerobic biofilm analysis. A laboratory-scale MBfR was operated for over 60 days with electron balance, structural analysis, and bacterial community identification. Results showed that anaerobic biofilm had an excellent removal of both selenate (95%) and nitrate (100%). Reduction of Selenate → Selenite → Se0 with hydrogen was the main pathway of anaerobic biofilm for selenate removal with amorphous Se0 precipitate accumulating in the biofilm. The element selenium was observed to be evenly distributed along the cross-sectional thin biofilm. A part of selenate (3%) was also reduced into methyl-selenide by heterotrophic bacteria. Additionally, Hydrogenophaga bacteria of ß-Proteobacteria, capable of both nitrate and selenate removal, worked as the dominant species (over 85%) in the biofilm and contributed to the stable removal of both nitrate and selenate. With the selenate input, bacteria with a capacity for both selenate and nitrate removal were also developed in the anaerobic biofilm community.

A New Design in Iterative Image Deblurring for Improved Robustness and Performance.

In many applications, image deblurring is a pre-requisite to improve the sharpness of an image before it can be further processed. Iterative methods are widely used for deblurring images but care must be taken to ensure that the iterative process is robust, meaning that the process does not diverge and reaches the solution reasonably fast, two goals that sometimes compete against each other. In practice, it remains challenging to choose parameters for the iterative process to be robust. We propose a new approach consisting of relaxed initialization and pixel-wise updates of the step size for iterative methods to achieve robustness. The first novel design of the approach is to modify the initialization of existing iterative methods to stop a noise term from being propagated throughout the iterative process. The second novel design is the introduction of a vectorized step size that is adaptively determined through the iteration to achieve higher stability and accuracy in the whole iterative process. The vectorized step size aims to update each pixel of an image individually, instead of updating all the pixels by the same factor. In this work, we implemented the above designs based on the Landweber method to test and demonstrate the new approach. Test results showed that the new approach can deblur images from noisy observations and achieve a low mean squared error with a more robust performance.

UNC119 is a binding partner of tumor suppressor Ras-association domain family 6 and induces apoptosis and cell cycle arrest by MDM2 and p53.

Ras-association domain family 6 (RASSF6) is a tumor suppressor that interacts with MDM2 and stabilizes p53. Caenorhabditis elegans unc-119 encodes a protein that is required for normal development of the nervous system. Humans have 2 unc-119 homologues, UNC119 and UNC119B. We have identified UNC119 as a RASSF6-interacting protein. UNC119 promotes the interaction between RASSF6 and MDM2 and stabilizes p53. Thus, UNC119 induces apoptosis by RASSF6 and p53. UNC119 depletion impairs DNA repair after DNA damage and results in polyploid cell generation. These findings support that UNC119 is a regulator of the RASSF6-MDM2-p53 axis and functions as a tumor suppressor.

BCL-XL binds and antagonizes RASSF6 tumor suppressor to suppress p53 expression.

RASSF6, a member of the tumor suppressor Ras-association domain family proteins, induces apoptosis in the caspase-dependent and caspase-independent manners. RASSF6 interacts with MDM2 and stabilizes p53. BCL-XL is a prosurvival member of BCL-2 family proteins. BCL-XL directly inhibits proapoptotic BAX and BAK. BCL-XL also traps tBID, a proapoptotic activator BH3-only protein, and sequesters p53. In addition, BCL-XL regulates the mitochondrial membrane permeability via voltage-dependent anion channel. In these manners, BCL-XL plays an antiapoptotic role. We report the interaction of BCL-XL with RASSF6. BCL-XL inhibits the interaction between RASSF6 and MDM2 and suppresses p53 expression. Consequently, BCL-XL antagonizes RASSF6-mediated apoptosis. Thus, the inhibition of RASSF6-mediated apoptosis also underlies the prosurvival role of BCL-XL.

Direct solid-state evidence of H2 -induced partial U(VI) reduction concomitant with adsorption by extracellular polymeric substances (EPS).

Adsorption of hexavalent uranium (U(VI)) by extracellular polymeric substances (EPS) has been studied, but the possibility of simultaneous U(VI) reduction mediated by EPS has not had experimental confirmation, as the reduction products have not yet been directly proven. Here, we reported the first direct evidence of lower-valent products of U(VI) immobilization by loosely associated EPS (laEPS) isolated from a fermenter strain of Klebsiella sp. J1 when the laEPS was exposed to H2 . During the 120-min tests for similarly 86% adsorption under O2 , N2 , and H2 , 8% more U was immobilized through a non-adsorptive pathway by the EPS for H2 than for N2 and O2 . A set of solid-state characterization tools (FT-IR, XPS, EELS, and TEM-EDX) confirmed partial reduction of U(VI) to lower-valence U, with the main reduced form being uraninite (UIV O2 ) nanoparticles, and the results reinforced the role of the reduction in accelerating U immobilization and shaping the characteristics of immobilized U in terms of valency, size, and crystallization. The laEPS, mostly comprised of carbohydrate and protein, contained non-cytochrome enzymes and electron carriers that could be responsible for electron transfer to U(VI). Taken together, our results directly confirm that EPS was able to mediate partial U(VI) reduction in the presence of H2 through non-cytochrome catalysis and that reduction enhanced overall U immobilization. Our study fills in some gaps of the microbe-mediated U cycle and will be useful to understand and control U removal in engineered reactors and in-situ bioremediation.

Enhanced Hydrogen Production from Sawdust Decomposition Using Hybrid-Functional Ni-CaO-Ca2SiO4 Materials.

A hybrid-functional material consisting of Ni as catalyst, CaO as CO2 sorbent, and Ca2SiO4 as polymorphic "active" spacer was synthesized by freeze-drying a mixed solution containing Ni, Ca and Si precursors, respectively, to be deployed during sawdust decomposition that generated gases mainly containing H2, CO, CO2 and CH4. The catalytic activity showed a positive correlation to the Ni loading, but at the expense of lower porosity and surface area with Ni loading beyond 20 wt %, indicating an optimal Ni loading of 20 wt % for Ni-CaO-Ca2SiO4 hybrid-functional materials, which enables ∼626 mL H2 (room temperature, 1 atm) produced from each gram of sawdust, with H2 purity in the product gas up to 68 vol %. This performance was superior over a conventional supported catalyst Ni-Ca2SiO4 that produced 443 mL H2 g-sawdust-1 under the same operating condition with a purity of ∼61 vol %. Although the Ni-CaO bifunctional material in its fresh form generated a bit more H2 (∼689 mL H2 g-sawdust-1), its cyclic performance decayed dramatically, resulting in H2 yield reduced by 62% and purity dropped from 73 to 49 vol % after 15 cycles. The "active" Ca2SiO4 spacer offers porosity and mechanical strength to the Ni-CaO-Ca2SiO4 hybrid-functional material, corresponding to its minor loss in reactivity over cycles (H2 yield reduced by only 7% and H2 purity dropped from 68 to 64 vol % after 15 cycles).

Quantitative Low-Dose Computed Tomography of the Lung Parenchyma and Airways for the Differentiation between Chronic Obstructive Pulmonary Disease and Asthma Patients.

BACKGROUND: It is difficult to differentiate between chronic obstructive pulmonary disease (COPD) and asthma in clinics; therefore, for diagnostic purposes, imaging-based measurements could be beneficial to differentiate between the two diseases. OBJECTIVES: We aim to analyze quantitative measurements of the lung and bronchial parameters that are provided by low-dose computed tomography (CT) to differentiate COPD and asthma from an imaging perspective. MATERIALS AND METHODS: 69 COPD patients, 52 asthma patients, and 20 healthy subjects were recruited to participate in CT imaging and pulmonary function tests (PFTs). Comparative analysis was performed to identify differences between COPD and asthma in CT measurements. PFT measurements enabled validation of the differentiation between COPD and asthma patients. RESULTS: There were significant differences among the COPD, asthma, and healthy control groups. The differences were more significant among the following: inspiratory emphysema index (EI)-950 (%), expiratory lung volume, expiratory mean lung density (MLD), and expiratory EI-950 (%) and EI-850 (%). The COPD group had a significantly higher EI-950 (%) than the asthma group (p = 0.008). There were significant differences among the three groups in lumen area (LA), wall area (WA), total area, and Pi10WA. The asthma group had significantly higher WA%/WV% than both the COPD (p = 0.002) and the control group (p = 0.012). There was high sensitivity in EI-950 (%), EI-850 (%) and expiratory MLD in the parenchyma and high sensitivity in LA and Pi10WA in small airways in the differential diagnosis of COPD and asthma. CONCLUSION: To aid the diagnosis, CT can provide quantitative measurements to differentiate between COPD and asthma patients.

Stomach frame-count-based attenuation correction of dynamic posterior view gastric emptying scintigraphy with continuous acquisition in children.

BACKGROUND: When performing dynamic gastric emptying scintigraphy with continuous acquisition in children, a single posterior view acquisition is preferred because it allows the young patient to more easily interact with a parent or technologist even though this method tends toward overestimating gastric emptying. OBJECTIVES: The objective of our study was to develop a new attenuation correction (AC) method to improve the accuracy of the time activity curve and the measurement of residual gastric emptying from 1-h posterior images of gastric emptying scintigraphy with continuous acquisition. MATERIALS AND METHODS: We developed a frame-count-based AC for gastric emptying scintigraphy from the posterior view (posterior AC method). We retrospectively reviewed 122 gastric emptying studies performed in children using conjugated posterior and anterior views, and evaluated the statistical differences between posterior only (without AC) and posterior AC using the geometric mean method as a reference standard. RESULTS: The residual values obtained using posterior AC were not significantly different (P=0.813) compared to those using the geometric mean while the values using the posterior only were significantly different (P<0.001) from the geometric mean. CONCLUSION: The proposed method can replace the geometric mean method to estimate gastric emptying residual fraction using patient-friendly posterior view without a significant difference in 1-h gastric emptying scintigraphy with continuous acquisition.

Joint volumetric extraction and enhancement of vasculature from low-SNR 3-D fluorescence microscopy images.

To simultaneously overcome the challenges imposed by the nature of optical imaging characterized by a range of artifacts including space-varying signal to noise ratio (SNR), scattered light, and non-uniform illumination, we developed a novel method that segments the 3-D vasculature directly from original fluorescence microscopy images eliminating the need for employing pre- and post-processing steps such as noise removal and segmentation refinement as used with the majority of segmentation techniques. Our method comprises two initialization and constrained recovery and enhancement stages. The initialization approach is fully automated using features derived from bi-scale statistical measures and produces seed points robust to non-uniform illumination, low SNR, and local structural variations. This algorithm achieves the goal of segmentation via design of an iterative approach that extracts the structure through voting of feature vectors formed by distance, local intensity gradient, and median measures. Qualitative and quantitative analysis of the experimental results obtained from synthetic and real data prove the effcacy of this method in comparison to the state-of-the-art enhancing-segmenting methods. The algorithmic simplicity, freedom from having a priori probabilistic information about the noise, and structural definition gives this algorithm a wide potential range of applications where i.e. structural complexity significantly complicates the segmentation problem.

Simultaneous Bioreduction of Multiple Oxidized Contaminants Using a Membrane Biofilm Reactor.

This study tests a hydrogen-based membrane biofilm reactor (MBfR) to investigate simultaneous bioreduction of selected oxidized contaminants, including nitrate (-N), sulfate (), bromate (), chromate (Cr(VI)) and para-chloronitrobenzene (p-CNB). The experiments demonstrate that MBfR can achieve high performance for contaminants bioreduction to harmless or immobile forms in 240 days, with a maximum reduction fluxes of 0.901 g -N/m2·d, 1.573 g /m2·d, 0.009 g /m2·d, 0.022 g Cr(VI)/m2·d, and 0.043 g p-CNB/m2·d. Increasing H2 pressure and decreasing influent surface loading enhanced removal efficiency of the reactor. Flux analysis indicates that nitrate and sulfate reductions competed more strongly than , Cr(VI) and p-CNB reduction. The average H2 utilization rate, H2 flux, and H2 utilization efficiency of the reactor were 0.026 to 0.052 mg H2/cm3·d, 0.024 to 0.046 mg H2/cm2·d, and 97.5% to 99.3% (nearly 100%). Results show the hydrogen-based MBfR may be suitable for removing multiple oxidized contaminants in drinking water or groundwater.