Publications by authors named "Jianguo Ma"

71 Publications

Rac Family Small GTPase 3 Correlates with Progression and Poor Prognosis in Bladder Cancer.

DNA Cell Biol 2021 Mar 17;40(3):469-481. Epub 2021 Feb 17.

Department of Urology, Third Hospital of Hebei Medical University, Shijiazhuang, China.

Bladder cancer (BC) is a common genitourinary malignancy worldwide. However, the molecular pathogenesis of BC remains unclear. The current study conducted bioinformatic analyses to discover key genes involved in BC progression. A total of 375 differentially expressed genes (DEGs) were screened in the GEO database and The Cancer Genome Atlas (TCGA) database, which were further evaluated by the core level in the protein-protein interaction network. (Rac family small GTPase 3), one of the top hub genes, was focused on for its gene expression and prognostic value in BC. Immunohistochemical assays indicated elevated levels in BC tissues compared with normal tissues. Overexpression of expression was closely associated with poor differentiation ( = 0.035), advanced TNM stage ( = 0.014), lymph metastasis ( = 0.033), and recurrence ( < 0.001). Kaplan-Meier and Cox proportional hazards analyses demonstrated that high expression indicated poor survival of BC patients, which could serve as an independent prognostic factor for overall survival (HR = 3.159,  = 0.023) and disease-free survival (HR = 4.633,  = 0.002). Moreover, bioinformatic analyses indicated that might be correlated with malignant phenotypes and immune infiltration of BC. Taken together, could be a novel prognostic biomarker for BC.
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http://dx.doi.org/10.1089/dna.2020.5613DOI Listing
March 2021

An asymmetric pulsed current-assisted electrochemical method for Sr(Ⅱ) extraction using supramolecular composites.

Chemosphere 2021 May 3;271:129531. Epub 2021 Jan 3.

State Key Laboratory of Nuclear Resources and Environment, East China University of Technology, Nanchang, Jiangxi 330013, China. Electronic address:

The development of effective, economical, and sustainable seawater extraction strontium techniques is of great significance to the environment and industrial needs. In this paper, an asymmetric pulsed current-assisted electrochemical (AP-CE) method was used to extract Sr(Ⅱ) from seawater using a carbon electrode modified by dibenzo-18-crown-6-ether and cellulose acetate. An asymmetric pulsed current was used to prevent unwanted cations from blocking adsorption sites to prevent water splitting. It also prevented the cellulose acetate membrane from sealing the crown ether. Compared with traditional physicochemical adsorption of Sr(Ⅱ), the AP-CE method achieved a higher removal efficiency and adsorption capacity. When the concentrations of Sr(Ⅱ) were 10, 20, 50, and 100 mg L, the removal efficiencies of Sr(Ⅱ) were 99.3%, 97.6%, 97.3%, and 96.1%, and the adsorption capacities of Sr(Ⅱ) were 14.9, 29.3, 73.0, and 144.2 mg g, respectively. This method exhibited excellent selectivity for Sr(Ⅱ) adsorption from simulated seawater, suggesting that the asymmetric pulse electrochemical method is promising for extracting strontium ions from seawater.
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http://dx.doi.org/10.1016/j.chemosphere.2021.129531DOI Listing
May 2021

Novel Decomposition Technique on Rational-Based Neuro-Transfer Function for Modeling of Microwave Components.

Micromachines (Basel) 2020 Jul 17;11(7). Epub 2020 Jul 17.

School of Microelectronics, Tianjin University, Tianjin 300072, China.

The rational-based neuro-transfer function (neuro-TF) method is a popular method for parametric modeling of electromagnetic (EM) behavior of microwave components. However, when the order in the neuro-TF becomes high, the sensitivities of the model response with respect to the coefficients of the transfer function become high. Due to this high-sensitivity issue, small training errors in the coefficients of the transfer function will result in large errors in the model output, leading to the difficulty in training of the neuro-TF model. This paper proposes a new decomposition technique to address this high-sensitivity issue. In the proposed technique, we decompose the original neuro-TF model with high order of transfer function into multiple sub-neuro-TF models with much lower order of transfer function. We then reformulate the overall model as the combination of the sub-neuro-TF models. New formulations are derived to determine the number of sub-models and the order of transfer function for each sub-model. Using the proposed decomposition technique, we can decrease the sensitivities of the overall model response with respect to the coefficients of the transfer function in each sub-model. Therefore, the modeling approach using the proposed decomposition technique can increase the modeling accuracy. Two EM parametric modeling examples are used to demonstrate the proposed decomposition technique.
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http://dx.doi.org/10.3390/mi11070696DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7407277PMC
July 2020

Suppression of reverberations at fiber tips for optical ultrasound sensing.

Opt Lett 2020 May;45(9):2526-2529

Fabry-Perot-based ultrasound sensors at fiber tips have performed high sensitivity and immunity of electromagnetic interference with a relatively compact size. Nevertheless, the reverberation at fiber tips causes a strong noise that degrades the sensing capability. Here we propose a fiber optical-based ultrasound sensor with three design approaches to reduce the reverberation, including designs with an eccentric core, absorptive shield, and arc edge. The effect was experimentally validated with a photoacoustic signal excitation. Compared with bare single-mode fibers in simulation, the low-reverberation design increased the signal-to-noise ratio by 32.1 dB with identical excitation. The experimental results demonstrated the "clean" response with almost invisible reverberations, which was validated by a commercial hydrophone. This research solved the reverberation problems and provided a low-noise design for fiber optic ultrasound sensing.
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http://dx.doi.org/10.1364/OL.389708DOI Listing
May 2020

Localized Building Titania-Graphene Charge Transfer Interfaces for Enhanced Photocatalytic Performance.

Langmuir 2020 May 23;36(17):4637-4644. Epub 2020 Apr 23.

State Key Laboratory of Nuclear Resources and Environment, East China University of Technology, Nanchang, 330013, Jiangxi, China.

Achieving high photocatalytic activity of titania-graphene composites calls for well-controlled titania size and efficient charge transfer interfaces. However, it is rather difficult because of easy restacking of graphene sheets and random nucleation and growth of titania nanoparticles in solution. Here, we reported a facile way to control the TiO sizes and interfaces by localizing the nucleation and growth of titania on graphene sheets, which prohibits both restacking of graphene and random growth of TiO. As a result, a composite with controllably less than 10-nm-sized TiO nanoparticles evenly distributed on thin graphene sheets was achieved. Thanks to the small size of titania and efficient charge transfer interfaces, the TiO/graphene composite exhibits a significant enhancement of photocatalytic H evolution activity, reaching 1.35 mmol g h. Furthermore, the composite also shows high photocatalytic activity on dye degradation under visible light illumination.
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http://dx.doi.org/10.1021/acs.langmuir.0c00297DOI Listing
May 2020

Enhancing the prebiotic effect of cellulose biopolymer in the gut by physical structuring via particle size manipulation.

Food Res Int 2020 05 23;131:108935. Epub 2019 Dec 23.

State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, PR China. Electronic address:

Cellulose is generally recognised as dietary fibre with no limit of permissible quantity in food, and its consumption may modulate digesta content and impact positively on the gastrointestinal physiology and gut microflora. However, cellulose in its native form possessed inherent undesirable physical properties, making it unattractive for food applications. Here, we postulate that by changing cellulose size to nanometric scale, its prebiotic effect would be altered and fermented differently in contrast with micro size cellulose by the gut microbiome and promote the yield of metabolites such as short chain fatty acids (SCFAs). Using faecal matter from three healthy human donors as microbial source, in vitro fermentation of variable size fractions of cellulose from the same were fermented under anaerobic conditions, and SCFAs as well Bifidobacterium selectively isolated and analysed. The increase in production of acetate (194%), butyrate (224%) and propionate (211%) after 24 h of fermentation was significantly promoted by the size reduction and revealed size-dependent relationship as exemplified R values >0.83. Consequently, gavaging rats with nanometric size cellulose (125 nm) significantly (p < 0.05) increased these SCFAs yields as well Bifidobacterium counts in contrast with both control and the micro scale size cellulose. Therefore, engineered nanocellulose might have beneficial physiological impact on the gut with improved prebiotic effect.
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http://dx.doi.org/10.1016/j.foodres.2019.108935DOI Listing
May 2020

LncRNA LINC00461 Promotes Colorectal Cancer Progression via miRNA-323b-3p/NFIB Axis.

Onco Targets Ther 2019 17;12:11119-11129. Epub 2019 Dec 17.

Department of General Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang, Hebei, People's Republic of China.

Background: LncRNA LINC00461 has been reported to play crucial regulatory roles in a variety of biological processes, including cell migration, cell invasion and cancer progression. However, its biological role in colorectal cancer (CRC) is completely unknown. The aim of our study was to explore the function of LINC00461 on CRC cells and the underlying mechanism.

Materials And Methods: CRC tumor tissues and cell lines derived from hospital and corporation. The expression level of LINC00461 in CRC tissues and cell lines were analyzed by quantitative real-time PCR (qRT-PCR). The effect of LINC00461 on cell proliferation, colony formation, migration and invasion were detected by CCK-8 assay, colony formation and transwell assay, respectively. In addition, cell apoptosis was analyzed by flow cytometry, and the role of LINC00461 on tumor growth was investigated by tumor xenografts in nude mice. The targets of LINC00461 were predicted by starBase v3.0 and confirmed by a dual-luciferase reporter system. The expression level of transcription factors of nuclear factor I B (NFIB), p21 and CDK2 was determined by Western blot or qRT-PCR. The NFIB expression levels in CRC tissues and mice tumors were analyzed by immunofluorescence assay (IHC).

Results: We found that the expression of LINC00461 was significantly overexpressed in CRC tissues and different cell lines, and the high level of LINC00461 expression was associated with poor overall survival. Downregulation of LINC00461 expression significantly suppressed the proliferation, migration and invasion of CRC cells and promoted cell apoptosis. We also found that LINC00461 could directly interact with miR-323b-3p. In addition, LINC00461 significantly increased the expression NFIB and CDK2, but, p21 was inhibited. Finally, we found that the growth of tumors in nude mice was suppressed upon LINC00461 deletion.

Conclusion: We demonstrated that LINC00461 may play an oncogenic role in CRC cells through NFIB signaling pathway by targeting miR-323b-3p. Our report showed that LINC00461 may be a prognostic biomarker and candidate therapeutic target for CRC.
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http://dx.doi.org/10.2147/OTT.S228798DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6925558PMC
December 2019

Facile preparation of collagen fiber-glycerol-carboxymethyl cellulose composite film by immersing method.

Carbohydr Polym 2020 Feb 3;229:115429. Epub 2019 Oct 3.

State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China. Electronic address:

Carboxymethyl cellulose (CMC) and glycerol were added by immersing neutralized collagen fiber paste into CMC/glycerol aqueous solutions with different mass ratios, forming composite films. CMC decreased the glycerol adsorption by 49.5%. The presence of CMC formed rougher film surface and more compact internal structure. Glycerol increased the distances between collagen molecules and decreased the relative triple helix contents. The tensile strength and Young's modulus of film in dry condition maximum respectively increased by 125% and 277% with the immersion in CMC (1.5%)/glycerol (4%) solution, compared to the sample immersed into pure glycerol solution, but mechanical properties decreased at high glycerol content. Besides, lower wet mechanical strength was observed as the addition of CMC, corresponding to the higher water swelling ratio of film. CMC also improved the shrinkage stability under boiling and the thermostability of film at a fixed glycerol level, but higher glycerol content caused the decrease of denaturation temperature of film.
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http://dx.doi.org/10.1016/j.carbpol.2019.115429DOI Listing
February 2020

Fiber optic-based laser interferometry array for three-dimensional ultrasound sensing.

Opt Lett 2019 Dec;44(23):5852-5855

Ultrasound imaging has been widely used in medical diagnosis due to its noninvasive, radiation-free, and real-time features. Optical resonance-based ultrasound sensors possess high sensitivity and broad bandwidth, but they need to operate in specific laser wavelengths or angles, which restricts their application in array sensing. Non-resonance-based optical sensing arrays did not perform with sufficient bandwidths or frame rates. Here we propose a fiber optic-based ultrasound sensing array with relatively high sensitivity, wide bandwidth, and three-dimensional (3D) sensing capabilities, which is potentially useful in medical imaging. Specifically, we experimentally demonstrated that the optical ultrasound sensor exhibited a noise equivalent pressure of 165 Pa, pressure nonlinearity of ${\lt 5}\% $<5%, $ - {3}\,\,{\rm dB}$-3dB angular uniformity of $ \pm {71}^\circ ,$±71, and $ - {6}\,\,{\rm dB}$-6dB bandwidth from $\sim{0}$∼0 to 27.2 MHz. For 3D sensing capabilities in spherical coordinates, the errors of the radial distance were within 5%, and the errors for the polar and azimuthal angles were within 4° and 2°, respectively. This demonstrated the viability and high performance of the array for 3D ultrasound sensing.
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http://dx.doi.org/10.1364/OL.44.005852DOI Listing
December 2019

Tailoring physicochemical properties of chitosan films and their protective effects on meat by varying drying temperature.

Carbohydr Polym 2019 May 7;212:150-159. Epub 2019 Feb 7.

State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi, 214122, China. Electronic address:

A higher temperature is usually used to increase the evaporation rate and thus reduce the drying time of chitosan films during casting preparation process. The effects of drying temperature (45-85 °C) on the microstructure, mechanical and barrier properties of chitosan films were investigated. Chitosan films dried at higher temperatures showed smoother internal microstructures by forming smaller micro-region aggregations and lower ordered crystalline structures. Higher drying temperature also decreased the intermolecular interactions of chitosan chains according to Fourier transform infrared spectroscopy analysis. These together led to the decrease in tensile strength, and the increase in water vapor and oxygen permeability. The film surface hydrophobicity remained unchanged at different drying temperatures, suggesting the applicability for chilled meat preservation. Chilled meat packaged with chitosan films had appropriate drip loss rate values as compared to those of the low-density polyethylene film and the blank sample, with lower thiobarbituric acid reactive substances, aerobic plate count, pH, and total volatile basic nitrogen values during 10 d storage. Moreover, films dried at lower temperatures showed superior juice retention capacity as well as superior preservation effect on chilled meat. The results found in this study can be used to better guide the selecting of drying temperature for chitosan film preparation.
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http://dx.doi.org/10.1016/j.carbpol.2019.02.019DOI Listing
May 2019

Interfacial Activity and Self-Assembly Behavior of Dissolved and Granular Octenyl Succinate Anhydride Starches.

Langmuir 2019 04 14;35(13):4702-4709. Epub 2019 Mar 14.

State Key Laboratory of Food Science and Technology , Jiangnan University , Wuxi 214122 , China.

The mechanisms of granular octenyl succinate anhydride (GOSA) and dissolved OSA (DOSA) starches in emulsion stabilization were investigated. In general, DOSA starch offered better emulsification activity by generating greater ζ-potential, lower particle size as well as long-term stability in comparison to GOSA starch of close degree of substitution (DS). A compact interface in DOSA starches was determined, resulting from an increased surface loading value of 2.37 mg/m in comparison to that of GOSA of 1.6 mg/m. Additionally, the irreversibly adsorbed and predominantly elastic interface of both DOSA and GOSA starches indicated that the DOSA starch may be a Pickering emulsifier rather than a biopolymer surfactant. This assumption was confirmed by transmission electron microscopy. Spherical micelles with average diameters of 100 nm were observed above the critical micelle concentration of 1 mg/mL. Moreover, samples G28 (representing DS of 0.028), D28, G16, and D16 could reach equilibrium interfacial tensions of 19.4, 16.5, 20.0, and 19.3 mN/m, respectively. However, due to the misleading contact angle as a result of rough surfaces and nonignorable gravity of GOSA starch, the energy escape equation failed to be employed in this study.
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http://dx.doi.org/10.1021/acs.langmuir.9b00069DOI Listing
April 2019

Effect of the Transition Points Mismatch on Quanta Image Sensors.

Sensors (Basel) 2018 Dec 10;18(12). Epub 2018 Dec 10.

School of Microelectronics, Tianjin University and Tianjin Key Laboratory of Imaging and Sensing Microelectronic Technology, No. 92 Weijin Road, Nankai District, Tianjin 300072, China.

Mathematical models and imaging models that show the relationship between the transition points mismatch of analog-to-digital converters (ADCs) and the bit error rate (BER) in single-bit and multi-bit quanta image sensors (QISs) are established. The mathematical models suggest that when the root-mean-square (r.m.s.) of the read noise in jots is 0.15e, the standard deviation of the transition points should be less than 0.15e to ensure that the BER is lower than 1% in the single-bit QIS, and 0.21e to ensure that the BER is lower than 5% in the multi-bit QIS. Based on the mathematical models, the imaging models prove that the fixed-pattern noise (FPN) increases with a stronger transition point mismatch. The imaging models also compare the imaging quality in the case of different spatial oversampling factors and bit depths. The grayscale similarity index (GSI) is 3.31 LSB and 1.74 LSB when the spatial oversampling factors are 256 and 4096, respectively, in the single-bit QIS. The GSI is 1.93 LSB and 1.13 LSB when the bit depth is 3 and 4, respectively, in the multi-bit QIS. It indicates that a higher bit depth and a larger spatial oversampling factor could reduce the effect of the transition points mismatch of1-bit or -bit ADCs.
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http://dx.doi.org/10.3390/s18124357DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6308565PMC
December 2018

Multiscale light-sheet for rapid imaging of cardiopulmonary system.

JCI Insight 2018 08 23;3(16). Epub 2018 Aug 23.

Department of Medicine, David Geffen School of Medicine at UCLA, and.

The ability to image tissue morphogenesis in real-time and in 3-dimensions (3-D) remains an optical challenge. The advent of light-sheet fluorescence microscopy (LSFM) has advanced developmental biology and tissue regeneration research. In this review, we introduce a LSFM system in which the illumination lens reshapes a thin light-sheet to rapidly scan across a sample of interest while the detection lens orthogonally collects the imaging data. This multiscale strategy provides deep-tissue penetration, high-spatiotemporal resolution, and minimal photobleaching and phototoxicity, allowing in vivo visualization of a variety of tissues and processes, ranging from developing hearts in live zebrafish embryos to ex vivo interrogation of the microarchitecture of optically cleared neonatal hearts. Here, we highlight multiple applications of LSFM and discuss several studies that have allowed better characterization of developmental and pathological processes in multiple models and tissues. These findings demonstrate the capacity of multiscale light-sheet imaging to uncover cardiovascular developmental and regenerative phenomena.
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http://dx.doi.org/10.1172/jci.insight.121396DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6141183PMC
August 2018

Protective effects of scoparone against ischemia‑reperfusion‑induced myocardial injury.

Mol Med Rep 2018 Aug 4;18(2):1752-1760. Epub 2018 Jun 4.

Department of Cardiology, The Third Hospital of Hebei Medical University, Shijiazhuang, Hebei 050051, P.R. China.

The present study aimed to investigate the protective effects and molecular mechanisms of scoparone on ischemia‑reperfusion (I/R) injury in primary cultured cardiac myocytes and rats. An in vivo rat model of I/R injury and an in vitro primary cultured cardiac myocyte model of oxygen‑glucose deprivation/reoxygenation were used to investigate the protective effects of scoparone. Cell viability, lactate dehydrogenase (LDH) release, superoxide dismutase (SOD), creatine kinase (CK) and malondialdehyde (MDA) levels, and reactive oxygen species (ROS) production were subsequently measured. In addition, cell apoptosis was assessed by terminal deoxynucleotidyl‑transferase‑mediated dUTP nick end labeling staining, and myocardial infarct area (IA) was determined by triphenyl tetrazolium chloride staining. Furthermore, the protein expression levels of B‑cell lymphoma 2 (Bcl‑2), Bcl‑2‑associated X protein (Bax), cytochrome c (Cyt C) and caspase‑3 were assessed by western blotting. The results demonstrated that treatment with scoparone markedly increased cell viability, SOD levels and Bcl‑2 protein expression, and decreased LDH release, MDA production, CK levels, ROS concentration, cell apoptotic rate, myocardial IA, and Bax, caspase‑3 and Cyt C protein expression. These findings indicated that scoparone may have a protective effect against I/R injury, thus suggesting that scoparone may be a considered a potential drug for the treatment of I/R injury via the inhibition of oxidative stress and cell apoptosis.
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http://dx.doi.org/10.3892/mmr.2018.9123DOI Listing
August 2018

High-Performance Flexible Single-Crystalline Silicon Nanomembrane Thin-Film Transistors with High- k NbO-BiO-MgO Ceramics as Gate Dielectric on a Plastic Substrate.

ACS Appl Mater Interfaces 2018 Apr 3;10(15):12798-12806. Epub 2018 Apr 3.

School of Microelectronics , Tianjin University , Tianjin 300072 , P. R. China.

A novel method of fabricating flexible thin-film transistor based on single-crystalline Si nanomembrane (SiNM) with high- k NbO-BiO-MgO (BMN) ceramic gate dielectric on a plastic substrate is demonstrated in this paper. SiNMs are successfully transferred to a flexible polyethylene terephthalate substrate, which has been plated with indium-tin-oxide (ITO) conductive layer and high- k BMN ceramic gate dielectric layer by room-temperature magnetron sputtering. The BMN ceramic gate dielectric layer demonstrates as high as ∼109 dielectric constant, with only dozens of pA current leakage. The Si-BMN-ITO heterostructure has only ∼nA leakage current at the applied voltage of 3 V. The transistor is shown to work at a high current on/off ratio of above 10, and the threshold voltage is ∼1.3 V, with over 200 cm/(V s) effective channel electron mobility. Bending tests have been conducted and show that the flexible transistors have good tolerance on mechanical bending strains. These characteristics indicate that the flexible single-crystalline SiNM transistors with BMN ceramics as gate dielectric have great potential for applications in high-performance integrated flexible circuit.
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http://dx.doi.org/10.1021/acsami.8b00470DOI Listing
April 2018

MEK inhibition leads to BRCA2 downregulation and sensitization to DNA damaging agents in pancreas and ovarian cancer models.

Oncotarget 2018 Feb 22;9(14):11592-11603. Epub 2018 Jan 22.

Cancer Research UK Drug-DNA Interactions Research Group, UCL Cancer Institute, Paul O'Gorman Building, University College London, London WC1E 6DD, UK.

Targeting the DNA damage response (DDR) in tumors with defective DNA repair is a clinically successful strategy. The RAS/RAF/MEK/ERK signalling pathway is frequently deregulated in human cancers. In this study, we explored the effects of MEK inhibition on the homologous recombination pathway and explored the potential for combination therapy of MEK inhibitors with DDR inhibitors and a hypoxia-activated prodrug. We studied effects of combining pimasertib, a selective allosteric inhibitor of MEK1/2, with olaparib, a small molecule inhibitor of poly (adenosine diphosphate [ADP]-ribose) polymerases (PARP), and with the hypoxia-activated prodrug evofosfamide in ovarian and pancreatic cancer cell lines. Apoptosis was assessed by Caspase 3/7 assay and protein expression was detected by immunoblotting. DNA damage response was monitored with γH2AX and RAD51 immunofluorescence staining. antitumor activity of pimasertib with evofosfamide were assessed in pancreatic cancer xenografts. We found that BRCA2 protein expression was downregulated following pimasertib treatment under hypoxic conditions. This translated into reduced homologous recombination repair demonstrated by levels of RAD51 foci. MEK inhibition was sufficient to induce formation of γH2AX foci, suggesting that inhibition of this pathway would impair DNA repair. When combined with olaparib or evofosfamide, pimasertib treatment enhanced DNA damage and increased apoptosis. The combination of pimasertib with evofosfamide demonstrated increased anti-tumor activity in BRCA wild-type Mia-PaCa-2 xenograft model, but not in the BRCA mutated BxPC3 model. Our data suggest that targeted MEK inhibition leads to impaired homologous recombination DNA damage repair and increased PARP inhibition sensitivity in BRCA-2 proficient cancers.
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http://dx.doi.org/10.18632/oncotarget.24294DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5837749PMC
February 2018

Age-related early/late variations of functional connectivity across the human lifespan.

Neuroradiology 2018 Apr 30;60(4):403-412. Epub 2018 Jan 30.

Tianjin International Joint Research Center for Neural Engineering, Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China.

Purpose: Many questions remain regarding how the brain develops, matures, and ages across the lifespan. The functional connectivity networks in the resting-state brain can reflect many of the characteristic changes in the brain that are associated with increasing age. Functional connectivity has been shown to be time-dependent over the course of a lifespan and even over the course of minutes. The lifespan strategies of all cognitive networks and how dynamic functional connectivity is associated with age are unclear.

Methods: In this paper, studies employing both linear and quadratic models to define new specific lifespan strategies, including early/late increase/decrease models, were conducted to explore the lifespan functional changes. A large data sample was retrieved from the publicly available data from the Nathan Kline Institute (N = 149 and ages 9-85). Both static and dynamic functional connectivity indexes were calculated including the static functional connectivity, the mean of the dynamic functional connectivity and variations in dynamic functional connectivity.

Results: The between-network connectivity results revealed early increases in the default-mode (DF) and cingulo-opercular network (CO)-associated network connectivities and a late increase in the fronto-parietal (FP)-associated network connectivity. These results depicted various lifespan strategies for different development stages and different cognitive networks across the lifespan. Additionally, the static FC and mean dynamic FC exhibited consistent results, and their variation exhibited a constant decrease with age across the entire age range.

Conclusion: These results (FDR-corrected p value < 0.05) suggest that the early/late variations in lifespan strategies could reflect an association between varied and complex circumstances and brain development.
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http://dx.doi.org/10.1007/s00234-017-1973-1DOI Listing
April 2018

Inductively powered wireless pacing via a miniature pacemaker and remote stimulation control system.

Sci Rep 2017 07 21;7(1):6180. Epub 2017 Jul 21.

Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA.

Pacemakers have existed for decades as a means to restore cardiac electrical rhythms. However, lead-related complications have remained a clinical challenge. While market-released leadless devices have addressed some of the issues, their pacer-integrated batteries cause new health risks and functional limitations. Inductive power transfer enables wireless powering of bioelectronic devices; however, Specific Absorption Rate and size limitations reduce power efficiency for biomedical applications. We designed a remote-controlled system in which power requirements were significantly reduced via intermittent power transfer to control stimulation intervals. In parallel, the cardiac component was miniaturized to facilitate intravascular deployment into the anterior cardiac vein. Given size constraints, efficiency was optimal via a circular receiver coil wrapped into a half-cylinder with a meandering tail. The pacemaker was epicardially tested in a euthanized pig at 60 beats per minute, 2 V amplitude, and 1 ms pulse width, restoring mean arterial pressure from 0 to 37 mmHg. Power consumption was 1 mW at a range of > 3 cm with no misalignment and at 2 cm with 45° displacement misalignment, 45° x-axis angular misalignment, or 45° y-axis angular misalignment. Thus, we demonstrated a remote-controlled miniaturized pacing system with low power consumption, thereby providing a basis for the next generation of wireless implantable devices.
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http://dx.doi.org/10.1038/s41598-017-06493-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5522478PMC
July 2017

Age-Related Decline in the Variation of Dynamic Functional Connectivity: A Resting State Analysis.

Front Aging Neurosci 2017 30;9:203. Epub 2017 Jun 30.

Tianjin International Joint Research Center for Neural Engineering, Academy of Medical Engineering and Translational Medicine, Tianjin UniversityTianjin, China.

Normal aging is typically characterized by abnormal resting-state functional connectivity (FC), including decreasing connectivity within networks and increasing connectivity between networks, under the assumption that the FC over the scan time was stationary. In fact, the resting-state FC has been shown in recent years to vary over time even within minutes, thus showing the great potential of intrinsic interactions and organization of the brain. In this article, we assumed that the dynamic FC consisted of an intrinsic dynamic balance in the resting brain and was altered with increasing age. Two groups of individuals ( = 36, ages 20-25 for the young group; = 32, ages 60-85 for the senior group) were recruited from the public data of the Nathan Kline Institute. Phase randomization was first used to examine the reliability of the dynamic FC. Next, the variation in the dynamic FC and the energy ratio of the dynamic FC fluctuations within a higher frequency band were calculated and further checked for differences between groups by non-parametric permutation tests. The results robustly showed modularization of the dynamic FC variation, which declined with aging; moreover, the FC variation of the inter-network connections, which mainly consisted of the frontal-parietal network-associated and occipital-associated connections, decreased. In addition, a higher energy ratio in the higher FC fluctuation frequency band was observed in the senior group, which indicated the frequency interactions in the FC fluctuations. These results highly supported the basis of abnormality and compensation in the aging brain and might provide new insights into both aging and relevant compensatory mechanisms.
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http://dx.doi.org/10.3389/fnagi.2017.00203DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5491557PMC
June 2017

Automated detection of pathologic white matter alterations in Alzheimer's disease using combined diffusivity and kurtosis method.

Psychiatry Res Neuroimaging 2017 Jun 12;264:35-45. Epub 2017 Apr 12.

The Neural Engineering & Rehabilitation lab, Tianjin University, Tianjin, China. Electronic address:

Diffusion tensor imaging (DTI) and diffusion kurtosis imaging (DKI) are important diffusion MRI techniques for detecting microstructure abnormities in diseases such as Alzheimer's. The advantages of DKI over DTI have been reported generally; however, the indistinct relationship between diffusivity and kurtosis has not been clearly revealed in clinical settings. In this study, we hypothesize that the combination of diffusivity and kurtosis in DKI improves the capacity of DKI to detect Alzheimer's disease compared with diffusivity or kurtosis alone. Specifically, a support vector machine-based approach was applied to combine diffusivity and kurtosis and to compare different indices datasets. Strict assessments were conducted to ensure the reliability of all classifiers. Then, data from the optimized classifiers were used to detect abnormalities. With the combination, high accuracy performances of 96.23% were obtained in 53 subjects, including 27 Alzheimer's patients. More highly scored abnormal regions were selected by the combination than alone. The results revealed that more precise diffusivity and complementary kurtosis mainly contributed to the high performance of the combination in DKI. This study provides further understanding of DKI and the relationship between diffusivity and kurtosis in pathologic white matter alterations in Alzheimer's disease.
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http://dx.doi.org/10.1016/j.pscychresns.2017.04.004DOI Listing
June 2017

Ambient Ultrafine Particle Ingestion Alters Gut Microbiota in Association with Increased Atherogenic Lipid Metabolites.

Sci Rep 2017 02 17;7:42906. Epub 2017 Feb 17.

Division of Cardiology, Department of Medicine, School of Medicine, University of California, Los Angeles, CA 90095, USA.

Ambient particulate matter (PM) exposure is associated with atherosclerosis and inflammatory bowel disease. Ultrafine particles (UFP, d < 0.1-0.2 μm) are redox active components of PM. We hypothesized that orally ingested UFP promoted atherogenic lipid metabolites in both the intestine and plasma via altered gut microbiota composition. Low density lipoprotein receptor-null (Ldlr) mice on a high-fat diet were orally administered with vehicle control or UFP (40 μg/mouse/day) for 3 days a week. After 10 weeks, UFP ingested mice developed macrophage and neutrophil infiltration in the intestinal villi, accompanied by elevated cholesterol but reduced coprostanol levels in the cecum, as well as elevated atherogenic lysophosphatidylcholine (LPC 18:1) and lysophosphatidic acids (LPAs) in the intestine and plasma. At the phylum level, Principle Component Analysis revealed significant segregation of microbiota compositions which was validated by Beta diversity analysis. UFP-exposed mice developed increased abundance in Verrocomicrobia but decreased Actinobacteria, Cyanobacteria, and Firmicutes as well as a reduced diversity in microbiome. Spearman's analysis negatively correlated Actinobacteria with cecal cholesterol, intestinal and plasma LPC18:1, and Firmicutes and Cyanobacteria with plasma LPC 18:1. Thus, ultrafine particles ingestion alters gut microbiota composition, accompanied by increased atherogenic lipid metabolites. These findings implicate the gut-vascular axis in a atherosclerosis model.
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http://dx.doi.org/10.1038/srep42906DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5314329PMC
February 2017

Light-sheet fluorescence imaging to localize cardiac lineage and protein distribution.

Sci Rep 2017 02 6;7:42209. Epub 2017 Feb 6.

Division of Cardiology, Department of Medicine, UCLA, Los Angeles, CA 90095, USA.

Light-sheet fluorescence microscopy (LSFM) serves to advance developmental research and regenerative medicine. Coupled with the paralleled advances in fluorescence-friendly tissue clearing technique, our cardiac LSFM enables dual-sided illumination to rapidly uncover the architecture of murine hearts over 10 by 10 by 10 mm in volume; thereby allowing for localizing progenitor differentiation to the cardiomyocyte lineage and AAV9-mediated expression of exogenous transmembrane potassium channels with high contrast and resolution. Without the steps of stitching image columns, pivoting the light-sheet and sectioning the heart mechanically, we establish a holistic strategy for 3-dimentional reconstruction of the "digital murine heart" to assess aberrant cardiac structures as well as the spatial distribution of the cardiac lineages in neonates and ion-channels in adults.
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http://dx.doi.org/10.1038/srep42209DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5292685PMC
February 2017

An Event-Based Neurobiological Recognition System with Orientation Detector for Objects in Multiple Orientations.

Front Neurosci 2016 4;10:498. Epub 2016 Nov 4.

School of Electronic Information Engineering, Tianjin University Tianjin, China.

A new multiple orientation event-based neurobiological recognition system is proposed by integrating recognition and tracking function in this paper, which is used for asynchronous address-event representation (AER) image sensors. The characteristic of this system has been enriched to recognize the objects in multiple orientations with only training samples moving in a single orientation. The system extracts multi-scale and multi-orientation line features inspired by models of the primate visual cortex. An orientation detector based on modified Gaussian blob tracking algorithm is introduced for object tracking and orientation detection. The orientation detector and feature extraction block work in simultaneous mode, without any increase in categorization time. An addresses lookup table (addresses LUT) is also presented to adjust the feature maps by addresses mapping and reordering, and they are categorized in the trained spiking neural network. This recognition system is evaluated with the MNIST dataset which have played important roles in the development of computer vision, and the accuracy is increased owing to the use of both ON and OFF events. AER data acquired by a dynamic vision senses (DVS) are also tested on the system, such as moving digits, pokers, and vehicles. The experimental results show that the proposed system can realize event-based multi-orientation recognition. The work presented in this paper makes a number of contributions to the event-based vision processing system for multi-orientation object recognition. It develops a new tracking-recognition architecture to feedforward categorization system and an address reorder approach to classify multi-orientation objects using event-based data. It provides a new way to recognize multiple orientation objects with only samples in single orientation.
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http://dx.doi.org/10.3389/fnins.2016.00498DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5095131PMC
November 2016

Ultrasonic Transducer-Guided Electrochemical Impedance Spectroscopy to Assess Lipid-Laden Plaques.

Sens Actuators B Chem 2016 Nov 7;235:154-161. Epub 2016 May 7.

Department of Bioengineering, School of Engineering and Applied Sciences, University of California, Los Angeles, CA 90095, USA; Division of Cardiology, Department of Medicine, School of Medicine, University of California, Los Angeles, CA 90095, USA; Department of Electrical Engineering, California Institute of Technology, Pasadena, CA 91125, USA.

Plaque rupture causes acute coronary syndromes and stroke. Intraplaque oxidized low density lipoprotein (oxLDL) is metabolically unstable and prone to induce rupture. We designed an intravascular ultrasound (IVUS)-guided electrochemical impedance spectroscopy (EIS) sensor to enhance the detection reproducibility of oxLDL-laden plaques. The flexible 2-point micro-electrode array for EIS was affixed to an inflatable balloon anchored onto a co-axial double layer catheter (outer diameter = 2 mm). The mechanically scanning-driven IVUS transducer (45 MHz) was deployed through the inner catheter (diameter = 1.3 mm) to the acoustic impedance matched-imaging window. Water filled the inner catheter to match acoustic impedance and air was pumped between the inner and outer catheters to inflate the balloon. The integrated EIS and IVUS sensor was deployed into the ex vivo aortas dissected from the fat-fed New Zealand White (NZW) rabbits (n=3 for fat-fed, n= 5 normal diet). IVUS imaging was able to guide the 2-point electrode to align with the plaque for EIS measurement upon balloon inflation. IVUS-guided EIS signal demonstrated reduced variability and increased reproducibility ( < 0.0001 for magnitude, < 0.05 for phase at < 15 kHz) as compared to EIS sensor alone ( < 0.07 for impedance, < 0.4 for phase at < 15 kHz). Thus, we enhanced topographic and EIS detection of oxLDL-laden plaques via a catheter-based integrated sensor design to enhance clinical assessment for unstable plaque.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5068578PMC
http://dx.doi.org/10.1016/j.snb.2016.04.179DOI Listing
November 2016

Simplified three-dimensional tissue clearing and incorporation of colorimetric phenotyping.

Sci Rep 2016 08 8;6:30736. Epub 2016 Aug 8.

Department of Bioengineering, University of California, Los Angeles, CA 90095, Los Angeles, USA.

Tissue clearing methods promise to provide exquisite three-dimensional imaging information; however, there is a need for simplified methods for lower resource settings and for non-fluorescence based phenotyping to enable light microscopic imaging modalities. Here we describe the simplified CLARITY method (SCM) for tissue clearing that preserves epitopes of interest. We imaged the resulting tissues using light sheet microscopy to generate rapid 3D reconstructions of entire tissues and organs. In addition, to enable clearing and 3D tissue imaging with light microscopy methods, we developed a colorimetric, non-fluorescent method for specifically labeling cleared tissues based on horseradish peroxidase conversion of diaminobenzidine to a colored insoluble product. The methods we describe here are portable and can be accomplished at low cost, and can allow light microscopic imaging of cleared tissues, thus enabling tissue clearing and imaging in a wide variety of settings.
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http://dx.doi.org/10.1038/srep30736DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4976371PMC
August 2016

Effect of Gallic acid on mechanical and water barrier properties of zein-oleic acid composite films.

J Food Sci Technol 2016 May 10;53(5):2227-35. Epub 2016 Jun 10.

Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, 214122 Wuxi, Jiangsu Province People's Republic of China.

In this study, the effect of gallic acid on mechanical and water barrier properties of zein-oleic acid 0-4 % composite films was investigated. Molecular weight distribution analysis was carried out to confirm gallic acid induced cross linking through change in molecular weight in fraction containing zein proteins. Results revealed that gallic acid treatment increased tensile strength from 17.9 MPa to 26.0 MPa, decreased water vapour permeability from 0.60 (g mm m(-2) h(-1) kPa(-1)) to 0.41 (g mm m(-2) h(-1) kPa(-1)), increased solubility from 6.3 % to 10.2 % and marginally increased elongation at break from 3.7 % to 4.2 % in zein films only. However, gallic acid treatment in zein-oleic composite films did not significantly influence mechanical and water barrier properties and in most instances irrespective of oleic acid concentration, the properties were negatively affected. Results from scanning electron microscopy showed that both gallic acid treated and untreated zein films and composite films containing 3 % oleic acid had a compact and homogeneous structure while those containing 4 % oleic acid had inhomogeneous structure. The findings have demonstrated that gallic acid treatment can significantly improve mechanical and water barrier properties especially in zein films only as opposed to when used in composite films using zein and oleic acid.
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http://dx.doi.org/10.1007/s13197-015-2167-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4921071PMC
May 2016

Ultrahigh Frequency (100 MHz-300 MHz) Ultrasonic Transducers for Optical Resolution Medical Imagining.

Sci Rep 2016 06 22;6:28360. Epub 2016 Jun 22.

School of Microelectronics, Xidian University, Xi'an 710071, China.

High resolution ultrasonic imaging requires high frequency wide band ultrasonic transducers, which produce short pulses and highly focused beam. However, currently the frequency of ultrasonic transducers is limited to below 100 MHz, mainly because of the challenge in precise control of fabrication parameters. This paper reports the design, fabrication, and characterization of sensitive broadband lithium niobate (LiNbO3) single element ultrasonic transducers in the range of 100-300 MHz, as well as their applications in high resolution imaging. All transducers were built for an f-number close to 1.0, which was achieved by press-focusing the piezoelectric layer into a spherical curvature. Characterization results demonstrated their high sensitivity and a -6 dB bandwidth greater than 40%. Resolutions better than 6.4 μm in the lateral direction and 6.2 μm in the axial direction were achieved by scanning a 4 μm tungsten wire target. Ultrasonic biomicroscopy images of zebrafish eyes were obtained with these transducers which demonstrate the feasibility of high resolution imaging with a performance comparable to optical resolution.
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http://dx.doi.org/10.1038/srep28360DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4916450PMC
June 2016

pH and temperature stability of (-)-epigallocatechin-3-gallate-β-cyclodextrin inclusion complex-loaded chitosan nanoparticles.

Carbohydr Polym 2016 09 28;149:340-7. Epub 2016 Apr 28.

State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, People's Republic of China. Electronic address:

The oxidative stability of (-)-epigallocatechin-3-gallate (EGCG) incorporated as inclusion complexes (ICs) in sulfobutylether-β-cyclodextrin sodium (SBE-β-CD) and then ionotropically crosslinked with chitosan hydrochloride (CSH) into nanoparticles were investigated. EGCG-loaded CSH-SBE-β-CD nanoparticles (CSNs) were physically unstable at higher pH and temperature. The particle size of CSNs was unchanged in the pH range of 3-5, but the microenvironment of EGCG-IC appeared to be intact until the pH increased to 6.5 by fluorescence spectroscopy. The physical structure of EGCG-ICs was also affected during storage in addition to CSNs, which was further affected as temperature increased from 25 to 55°C. The decrease in antioxidant activities of EGCG-ICs and free EGCG with increasing pH, storage time and temperature were modest compared to the prominent decreases in antioxidant activities of EGCG-loaded CSNs. The extreme entrapment of EGCG-ICs and/or free EGCG in the aggregated CSNs restricted the release of EGCG, thus inhibiting the antioxidant activities.
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http://dx.doi.org/10.1016/j.carbpol.2016.04.100DOI Listing
September 2016

Ex Vivo Porcine Arterial and Chorioallantoic Membrane Acoustic Angiography Using Dual-Frequency Intravascular Ultrasound Probes.

Ultrasound Med Biol 2016 09 31;42(9):2294-307. Epub 2016 May 31.

Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, North Carolina, USA; Biomedical Research Imaging Center, University of North Carolina, Chapel Hill, North Carolina, USA. Electronic address:

The presence of blood vessels within a developing atherosclerotic plaque has been found to be correlated with increased plaque vulnerability and ensuing cardiac events, however, detection of coronary intraplaque neovascularization poses a significant challenge in the clinic. We describe here a new in vivo intravascular ultrasound imaging method using a dual-frequency transducer to visualize contrast flow in microvessels with high specificity. This method uses a specialized transducer capable of exciting contrast agents at a low frequency (5.5 MHz) while detecting their nonlinear superhamonics at a much higher frequency (37 MHz). In vitro evaluation of the approach was performed in a microvascular phantom to produce 3-D renderings of simulated vessel patterns and to determine image quality metrics as a function of depth. Furthermore, we describe the ability of the system to detect microvessels both ex vivo using porcine arteries and in vivo using the chorioallantoic membrane of a developing chicken embryo with optical confirmation. Dual-frequency contrast-specific imaging was able to resolve vessels similar in size to those found in vulnerable atherosclerotic plaques at clinically relevant depths. The results of this study add to the support for further evaluation and translation of contrast-specific imaging in intravascular ultrasound for the detection of vulnerable plaques in atherosclerosis.
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http://dx.doi.org/10.1016/j.ultrasmedbio.2016.04.008DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5653969PMC
September 2016

Cardiac Light-Sheet Fluorescent Microscopy for Multi-Scale and Rapid Imaging of Architecture and Function.

Sci Rep 2016 Mar 3;6:22489. Epub 2016 Mar 3.

Department of Bioengineering, UCLA, Los Angeles, CA, USA.

Light Sheet Fluorescence Microscopy (LSFM) enables multi-dimensional and multi-scale imaging via illuminating specimens with a separate thin sheet of laser. It allows rapid plane illumination for reduced photo-damage and superior axial resolution and contrast. We hereby demonstrate cardiac LSFM (c-LSFM) imaging to assess the functional architecture of zebrafish embryos with a retrospective cardiac synchronization algorithm for four-dimensional reconstruction (3-D space + time). By combining our approach with tissue clearing techniques, we reveal the entire cardiac structures and hypertrabeculation of adult zebrafish hearts in response to doxorubicin treatment. By integrating the resolution enhancement technique with c-LSFM to increase the resolving power under a large field-of-view, we demonstrate the use of low power objective to resolve the entire architecture of large-scale neonatal mouse hearts, revealing the helical orientation of individual myocardial fibers. Therefore, our c-LSFM imaging approach provides multi-scale visualization of architecture and function to drive cardiovascular research with translational implication in congenital heart diseases.
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http://dx.doi.org/10.1038/srep22489DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4776137PMC
March 2016