Publications by authors named "Ran Shi"

33 Publications

First Identification of a Patient with Prosthesis-Related Infection Caused by an MCR-1.1-Producing ST131 After Rhinoplasty.

Infect Drug Resist 2021 26;14:249-257. Epub 2021 Jan 26.

Emergency Department, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, People's Republic of China.

Background: The most common procedure of rhinoplasty is the implantation of a synthetic prosthesis. However, the complications, especially postoperative infection, could lead the suboptimal aesthetic outcome, economic losses and health threats. There is currently little literature providing an incidence of rhinoplasty infection and microbiological and antimicrobial resistance situations.

Methods: Therefore, we performed a retrospective observational study which included 173 patients who received a rhinoplasty from 1 January 2015, to 31 December 2019, in the department of plastic surgery of a tertiary hospital in Guangzhou, China. The samples from the infection site were collected and performed the bacterial culture. The antimicrobial susceptibility testing was performed by VITEK and minimum inhibition concentration testing. The whole-genome sequencing was performed by Illumina Hiseq4000 platform.

Results: We found that eight (4.6%) patients were infected by (6), (1) and (1), of which are susceptible to most antimicrobials. Remarkably, RS1231 was resistant to colistin and polymyxin B which conferred by locating on an IncI2 plasmid with 59,170-bp sequence length. Through sequence comparison, we speculate that the pRS1231S-MCR-1 was derived from animal sources. Besides, RS1231 belongs to ST131 O25:H4-fimH22 pandemic subclone and phylogroup B2, which can induce a broad variety of infections.

Conclusion: Our study provided a rhinoplasty infection incidence, microbiological and antimicrobial resistance prevalence data, and revealed, to our knowledge, the first case of postoperative infection of rhinoplasty by -positive, highly susceptible, and remarkably virulent isolate.
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http://dx.doi.org/10.2147/IDR.S295801DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7847383PMC
January 2021

Global transcriptomic analysis of functional oligosaccharide metabolism in Pediococcus pentosaceus.

Appl Microbiol Biotechnol 2021 Feb 29;105(4):1601-1614. Epub 2021 Jan 29.

Key Laboratory of Food Bioengineering (China National Light Industry), College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China.

Lactic acid bacteria (LAB) are important in food fermentation and may enhance overall host health. Previous studies to explore LAB metabolism mainly focused on the genera Lacticaseibacillus and Lactococcus. Pediococcus pentosaceus, historically recognized as an important food fermentation bacterial strain, can produce bacteriocins and occasionally demonstrated probiotic functionalities. This study thoroughly surveyed the growth kinetic of three P. pentosaceus isolates in various culture formulations, especially in fructooligosaccharide (FOS), xylooligosaccharide (XOS), or konjac mannooligosaccharide (KMOS) conditions. Results showed that P. pentosaceus effectively metabolized KMOS, the culture of which led to 23.6-fold population increase. However, FOS and XOS were less metabolized by P. pentosaceus. On functional oligosaccharide cultures, P. pentosaceus could result in higher population proliferation, more acidified fermentation environment, and higher glycoside hydrolysis activities in the culture. RNA-Seq analysis classified 1572 out of 1708 putative genes as mRNA-coding genes. The dataset also revealed that the three functional oligosaccharides led to extensive global functional gene regulations. Phosphate conservation and utilization efficiency enhancement may serve as a leading transcriptional regulation direction in functional oligosaccharide metabolisms. In summary, these discovered metabolic characteristics could be employed to support future studies. KEY POINTS: • Konjac mannooligosaccharides effectively promoted P. pentosaceus proliferation. • Functional genes were highly regulated in functional oligosaccharide utilization. • Phosphate conservation was an important transcriptional regulation direction.
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http://dx.doi.org/10.1007/s00253-021-11120-5DOI Listing
February 2021

Personal Fixations-Based Object Segmentation With Object Localization and Boundary Preservation.

IEEE Trans Image Process 2021 31;30:1461-1475. Epub 2020 Dec 31.

As a natural way for human-computer interaction, fixation provides a promising solution for interactive image segmentation. In this paper, we focus on Personal Fixations-based Object Segmentation (PFOS) to address issues in previous studies, such as the lack of appropriate dataset and the ambiguity in fixations-based interaction. In particular, we first construct a new PFOS dataset by carefully collecting pixel-level binary annotation data over an existing fixation prediction dataset, such dataset is expected to greatly facilitate the study along the line. Then, considering characteristics of personal fixations, we propose a novel network based on Object Localization and Boundary Preservation (OLBP) to segment the gazed objects. Specifically, the OLBP network utilizes an Object Localization Module (OLM) to analyze personal fixations and locates the gazed objects based on the interpretation. Then, a Boundary Preservation Module (BPM) is designed to introduce additional boundary information to guard the completeness of the gazed objects. Moreover, OLBP is organized in the mixed bottom-up and top-down manner with multiple types of deep supervision. Extensive experiments on the constructed PFOS dataset show the superiority of the proposed OLBP network over 17 state-of-the-art methods, and demonstrate the effectiveness of the proposed OLM and BPM components. The constructed PFOS dataset and the proposed OLBP network are available at https://github.com/MathLee/OLBPNet4PFOS.
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http://dx.doi.org/10.1109/TIP.2020.3044440DOI Listing
December 2020

Edge Influence on Charge Carrier Localization and Lifetime in CHNHPbBr Perovskite: Quantum Dynamics Simulation.

J Phys Chem Lett 2020 Nov 13;11(21):9100-9109. Epub 2020 Oct 13.

Departments of Chemistry, and Physics and Astronomy, University of Southern California, Los Angeles, California 90089, United States.

The distribution of charge carriers in metal halide perovskites draws strong interest from the solar cell community, with experiments demonstrating that edges of various microstructures can improve material performance. This is rather surprising because edges and grain boundaries are often viewed as the main source of charge traps. We demonstrate by quantum dynamics simulations that edges of the CHNHPbBr perovskite create shallow trap states that mix well with the valence and conduction bands of the bulk and therefore support mobile charge carriers. Charges are steered to the edges energetically, facilitating dissociation of photo-generated excitons into free carriers. The edge-driven charge separation extends carrier lifetimes because of decreased overlap of the electron and hole wave functions, which leads to reduction of the nonadiabatic coupling responsible for nonradiative electron-hole recombination. Reduction of spatial symmetry near the edges activates additional vibrational modes that accelerate coherence loss within the electronic subsystem, further extending carrier lifetimes. Enhanced atomic motions at edges increase fluctuations of edge energy levels, enhancing mixing with band states and improving charge mobility. The simulations contribute to the atomistic understanding of the unusual properties of metal halide perovskites, generating the fundamental knowledge needed to design high-performance optoelectronic devices.
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http://dx.doi.org/10.1021/acs.jpclett.0c02800DOI Listing
November 2020

Author Correction: Neutron diffraction analysis of stress and strain partitioning in a two-phase microstructure with parallel-aligned phases.

Sci Rep 2020 Oct 7;10(1):17019. Epub 2020 Oct 7.

Material Design and Structural Integrity Lab, Faculty of Engineering and Computer Sciences, Osnabrück University of Applied Sciences, Albrecht St. 30, 49076, Osnabrück, Germany.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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http://dx.doi.org/10.1038/s41598-020-74028-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7541475PMC
October 2020

Preparation and Properties of an Alginate-Based Fiber Separator for Lithium-Ion Batteries.

ACS Appl Mater Interfaces 2020 Aug 17;12(34):38175-38182. Epub 2020 Aug 17.

School of Materials Science and Engineering, Qingdao University, Qingdao 266071, China.

The membrane is one of the key inner parts of lithium-ion batteries, which determines the interfacial structure and internal resistance, ultimately affecting the capacity, cycling, and safety performance of the cell. In this article, an alginate-based fiber composite membrane was successfully fabricated from cellulose and calcium alginate with flame-retardant properties via a traditional papermaking process. In the membrane, the calcium alginate plays a bridging role and the cellulose acts as a filler. After 100 cycles, lithium-ion batteries by the alginate-based fiber separator exhibited better capacity retention ratios (approximately 90%) compared with those of commercial PP separators. Furthermore, the alginate-based fiber separator demonstrated fine thermal stability and electrochemical properties, showing a stable charge-discharge capability and no hot melt shrinkage at higher temperatures, which is a breakthrough in improving the safety of the cell. This research affords a new way for the large-scale fabrication of safe lithium-ion battery separators.
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http://dx.doi.org/10.1021/acsami.0c10630DOI Listing
August 2020

Neutron diffraction analysis of stress and strain partitioning in a two-phase microstructure with parallel-aligned phases.

Sci Rep 2020 Aug 11;10(1):13536. Epub 2020 Aug 11.

Material Design and Structural Integrity Lab, Faculty of Engineering and Computer Sciences, Osnabrück University of Applied Sciences, Albrecht St. 30, 49076, Osnabrück, Germany.

By time-of-flight (TOF) neutron diffraction experiments, the influence of segregation-induced microstructure bands of austenite (γ) and martensite (α' ) phases on the partitioning of stress and strain between these phases was investigated. Initially, tensile specimens of a Co-added stainless steel were heat treated by quenching and partitioning (Q&P) processing. Tensile specimens were subsequently loaded at 350 °C parallel to the length of the bands within the apparent elastic limit of the phase mixture. Lattice parameters in both axial and transverse directions were simultaneously measured for both phases. The observation of a lattice expansion for the γ phase in the transverse direction indicated a constraint on the free transverse straining of γ arising from the banded microstructure. The lateral contraction of α' imposed an interphase tensile microstress in the transverse direction of the γ phase. The multiaxial stress state developed in the γ phase resulted in a large deviation from the level of plastic strain expected for uniaxial loading of single phase γ. Since segregation-induced banded microstructures commonly occur in many engineering alloys, the analysis of stress and strain partitioning with the present Q&P steel can be used to interpret the observations made for further engineering alloys with two-phase microstructures.
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http://dx.doi.org/10.1038/s41598-020-70299-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7421942PMC
August 2020

Biochemical characterization of a novel α-L-fucosidase from Pedobacter sp. and its application in synthesis of 3'-fucosyllactose and 2'-fucosyllactose.

Appl Microbiol Biotechnol 2020 Jul 9;104(13):5813-5826. Epub 2020 May 9.

Key Laboratory of Food Bioengineering (China National Light Industry), College of Food Science and Nutritional Engineering, China Agricultural University, No.17 Qinghua Donglu, Haidian District, Beijing, 100083, China.

Fucosyllactoses have gained much attention owing to their multiple functions, including prebiotic, immune, gut, and cognition benefits. In this study, human milk oligosaccharide (HMO) 2'-fucosyllactose (α-L-Fuc-(1,2)-D-Galβ-1,4-Glu, 2'FL) and its isomer 3'-fucosyllactose (α-L-Fuc-(1,3)-D-Galβ-1,4-Glu, 3'FL) with potential prebiotic effect were synthesized efficiently by a novel recombinant α-L-fucosidase. An α-L-fucosidase gene (PbFuc) from Pedobacter sp. CAU209 was successfully cloned and expressed in Escherichia coli (E. coli). The deduced amino acid sequence shared the highest identity of 36.8% with the amino sequences of other reported α-L-fucosidases. The purified α-L-fucosidase (PbFuc) had a molecular mass of 50 kDa. The enzyme exhibited specific activity (26.3 U/mg) towards 4-nitrophenyl-α-L-fucopyranoside (pNP-FUC), 3'FL (8.9 U/mg), and 2'FL (3.4 U/mg). It showed the highest activity at pH 5.0 and 35 °C, respectively. PbFuc catalyzed the synthesis of 3'FL and 2'FL through a transglycosylation reaction using pNP-FUC as donor and lactose as acceptor, and total conversion ratio was up to 85% at the optimized reaction conditions. The synthesized mixture of 2'FL and 3'FL promoted the growth of Lactobacillus delbrueckii subsp. bulgaricus NRRL B-548, L. casei subsp. casei NRRL B-1922, L. casei subsp. casei AS 1.2435, and Bifidobacterium longum NRRL B-41409. However, the growths of E. coli ATCC 11775, S. enterica AS 1.1552, L. monocytogenes CICC 21635, and S. aureus AS 1.1861 were not stimulated by the mixture of 2'FL and 3'FL. Overall, our findings suggest that PbFuc possesses a great potential for the specific synthesis of fucosylated compounds.Key Points• A novel α-L-fucosidase (PbFuc) from Pedobacter sp. was cloned and expressed.• PbFuc showed the highest hydrolysis activity at pH 5.0 and 35 °C, respectively.• It was used for synthesis of 3'-fucosyllactose (3'FL) and 2'-fucosyllactose (2'FL).• The mixture of 3'FL and 2'FL promoted the growth of some Lactobacillus sp. and Bifidobacteria sp.
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http://dx.doi.org/10.1007/s00253-020-10630-yDOI Listing
July 2020

Ferroelastic domains drive charge separation and suppress electron-hole recombination in all-inorganic halide perovskites: time-domain ab initio analysis.

Nanoscale Horiz 2020 Apr 9;5(4):683-690. Epub 2020 Jan 9.

College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing, 100875, People's Republic of China.

All-inorganic perovskites have great potential in photovoltaic applications and their performance is subject to phonon-assisted charge recombination dynamics. Local microstructures, such as ferroelastic domains, are considered to have a significant influence on the charge carrier lifetime in the CsPbBr perovskite. Employing a combination of time-domain density functional theory and nonadiabatic (NA) molecular dynamics simulations, we demonstrate that the formation of ferroelastic domains weakens the NA coupling and suppresses the non-radiative electron-hole recombination. This effect originates from the ferroelastic domains separating electron and hole wave functions spatially and decreasing the NA coupling by a factor of 2.4 compared to pristine CsPbBr, delaying electron-hole recombination by a factor of 4.2. We also show that symmetry breaking enhances electronic-vibrational interactions, activating more phonon modes and accelerating quantum decoherence by 1 fs or so, which further slows recombination. Both factors compete successfully with the slightly reduced bandgap of about 0.2 eV and prolong the charge carrier lifetime to several nanoseconds. Our study advances the understanding of the atomistic mechanism for inhibited recombination in the CsPbBr perovskite in the presence of ferroelastic domains, providing an effective route to design high-performance all-inorganic halide perovskites.
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http://dx.doi.org/10.1039/c9nh00717bDOI Listing
April 2020

Cancer-associated fibroblasts promote cell growth by activating ERK5/PD-L1 signaling axis in colorectal cancer.

Pathol Res Pract 2020 Apr 13;216(4):152884. Epub 2020 Feb 13.

Department of Oncology, The Affiliated Huai'an No.1 People's Hospital of Nanjing Medical University, Huai'an, Jiangsu, PR China. Electronic address:

Background: Colorectal cancer (CRC) is one of the most common diseases, accounting for about 10 % cancer-related deaths. Previous studies have found that caner-associated fibroblasts (CAFs) are closely related to the occurrence and metastasis of CRC, but the detailed mechanism is not precise.

Methods: Tumor cells and fibroblasts were co-cultured with a transwell system. Cell Counting Kit-8 and colony formation assays were performed to test the ability of cell proliferation. The flow cytometry was used to detect cell apoptosis. Western Blot was performed to assess protein expression levels. Quantitative real-time PCR was performed to detect mRNA expression levels. ERK5-IN-1 was used to inhibit the autophosphorylation of ERK5.

Results: CAFs promoted cell proliferation and inhibited cell apoptosis in CRC cells. CAFs promoted the phosphorylation of ERK5 and the expression of programmed death-ligand 1 (PD-L1). Activated ERK5 promotes cell proliferation and inhibited cell apoptosis in CRC cells. The expression levels of ERK5 correlated with the expression of PD-L1 in CRC cells. CAFs promote cell growth by activating the ERK5/PD-L1 signaling axis in colorectal cancer.

Conclusions: CAFs significantly promoted cell proliferation and inhibited cell apoptosis in CRC cells, which features are dependent on regulating the ERK5/PD-L1 signaling axis.
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http://dx.doi.org/10.1016/j.prp.2020.152884DOI Listing
April 2020

Amentoflavone suppresses amyloid β1-42 neurotoxicity in Alzheimer's disease through the inhibition of pyroptosis.

Life Sci 2019 Dec 10;239:117043. Epub 2019 Nov 10.

Department of Rehabilitation Medicine, The First Affiliated Hospital of Shandong First Medical University, Jinan, China. Electronic address:

Background: The accumulation of Amyloid β (Aβ) plays key roles in Alzheimer's disease (AD) by inducing intracellular reactive oxygen species (ROS) and neuronal cell death. In this study, we aimed to identify the neuroprotective mechanisms of amentoflavone (AF) in Aβ-induce neuronal cell injury.

Materials And Methods: The animal model was established by injecting Aβ into the bilateral hippocampus. The effect of AF on Aβ-induced neurological dysfunction was examined using the Y-maze and radical maze tests. The hippocampal neuron viability was examined using Nissl staining and TUNEL assay. On the other hand, in vitro studies were conducted using SH-SY5Y cells. The expression level of marker proteins was measured using western blot. The activity of caspase-1 and the levels of pro-inflammatory cytokines were determined using ELISA assay. AMPKα knock down was carried out by transfecting SH-SY5Y cells with siRNA against AMPK transcript.

Results: Neurological tests showed that AF significantly attenuated Aβ-induced neurological dysfunction. AF suppressed Aβ-induced pyroptosis in the hippocampal region of the rat model, which was associated with the modulation of AMPK/GSK3β signaling. Similar results were obtained in vitro in SH-SY5Y cells exposed to Aβ, showing that the neuroprotective activity of AF is mediated by suppressing pyroptosis through AMPK/GSK3β signaling.

Conclusion: AF inhibits Aβ-induced neurotoxicity in animal and cellular models through AMPK/GSK3β-mediated pyroptosis suppression. Our results highlight AF as a clinical compound for the prevention and treatment of AD.
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http://dx.doi.org/10.1016/j.lfs.2019.117043DOI Listing
December 2019

Hole Localization Inhibits Charge Recombination in Tin-Lead Mixed Perovskites: Time-Domain ab Initio Analysis.

Authors:
Ran Shi Run Long

J Phys Chem Lett 2019 Nov 15;10(21):6604-6612. Epub 2019 Oct 15.

College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education , Beijing Normal University , Beijing 100875 , People's Republic of China.

Using time domain density functional theory combined with nonadiabatic molecular dynamics, we demonstrate that the Sn dopants favor forming localized hole states with different extent at low and high doping concentrations, mimicking the small and large polarons, while retain the electron wave functions comparable with the pristine system, leading to nonadiabatic coupling decreasing by a factor of 45% and 38% and bandgap reduction by 0.04 and 0.27 eV, respectively. Furthermore, replacing heavier Pb with lighter Sn increases atomic fluctuations and accelerates loss of quantum coherence, in particular even faster at higher Sn doping concentration. As a result, the interplay among the bandgap, NA coupling, and decoherence time delays the electron-hole recombination by a factor of 3.5 and 1.3 at low and high doping concentration. Our study reveals the atomistic mechanisms of suppressed recombination dependence on Sn doping concentration, providing a new way to design high performance mixed perovskites.
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http://dx.doi.org/10.1021/acs.jpclett.9b02786DOI Listing
November 2019

A meta-analysis of the relationship between anxiety and attentional control.

Clin Psychol Rev 2019 08 8;72:101754. Epub 2019 Jul 8.

School of Psychology, Faculty of Science, Brennan MacCallum Bldg (A18), University of Sydney, NSW 2006, Australia.

Attentional Control Theory (ACT) (Eysenck & Derakshan, 2011) proposes that attention control (AC) deficits are central to the development of anxiety. This meta-analysis investigated the size and nature of AC deficits in anxious compared to non-anxious participants. We made the following hypotheses based on ACT: i) anxiety-related AC deficits occur in the AC components of inhibition and switching, but not updating; ii) deficits will be more pronounced for AC efficiency (reaction times) than effectiveness (accuracy); iii) studies with high cognitive load conditions will observe greater deficits than studies with normal cognitive load; iv) age and anxiety level will moderate the effect of anxiety on AC. Fifty-eight studies (N = 8292) met inclusion criteria. The meta-analysis revealed a significant AC deficit for high compared to low anxiety participants (Hedges' g = -0.58). Overall, results supported assumptions of ACT: anxiety produced significant deficits in AC efficiency but not effectiveness; these deficits occurred in inhibition and switching but not updating and studies with high cognitive load conditions found larger anxiety related AC deficits. Age moderated the relationship between anxiety and AC in behavioural studies and anxiety severity moderated this relationship in self-report studies. Theoretical implications of the results are discussed, and future directions for research are proposed. This meta-analysis has been registered with PROSPERO in 2016, Registration number: CRD42016036927.
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http://dx.doi.org/10.1016/j.cpr.2019.101754DOI Listing
August 2019

Characterizing the Collagen Network Structure and Pressure-Induced Strains of the Human Lamina Cribrosa.

Invest Ophthalmol Vis Sci 2019 06;60(7):2406-2422

Department of Mechanical Engineering, The Johns Hopkins University, Baltimore, Maryland, United States.

Purpose: The purpose of this study was to measure the 2D collagen network structure of the human lamina cribrosa (LC), analyze for the correlations with age, region, and LC size, as well as the correlations with pressure-induced strains.

Methods: The posterior scleral cups of 10 enucleated human eyes with no known ocular disease were subjected to ex vivo inflation testing from 5 to 45 mm Hg. The optic nerve head was imaged by using second harmonic generation imaging (SHG) to identify the LC collagen structure at both pressures. Displacements and strains were calculated by using digital volume correlation of the SHG volumes. Nine structural features were measured by using a custom Matlab image analysis program, including the pore area fraction, node density, and beam connectivity, tortuosity, and anisotropy.

Results: All strain measures increased significantly with higher pore area fraction, and all but the radial-circumferential shear strain (Erθ) decreased with higher node density. The maximum principal strain (Emax) and maximum shear strain (Γmax) also increased with larger beam aspect ratio and tortuosity, respectively, and decreased with higher connectivity. The peripheral regions had lower node density and connectivity, and higher pore area fraction, tortuosity, and strains (except for Erθ) than the central regions. The peripheral nasal region had the lowest Emax, Γmax, radial strain, and pore area fraction.

Conclusions: Features of LC beam network microstructure that are indicative of greater collagen density and connectivity are associated with lower pressure-induced LC strain, potentially contributing to resistance to glaucomatous damage.
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http://dx.doi.org/10.1167/iovs.18-25863DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6545820PMC
June 2019

Elastic-Plastic Transformation of Polyelectrolyte Complex Hydrogels from Chitosan and Sodium Hyaluronate.

Macromolecules 2018 Nov 31;51(21):8887-8898. Epub 2018 Oct 31.

Faculty of Advanced Life Science, Hokkaido University, Sapporo 001-0021, Japan.

Hydrogels formed by polyelectrolyte complexation (PEC) of oppositely charged biopolymers, free of any chemical additives, are promising biomaterials. In this work, the mechanical behavior of hydrogels consisting of positively charged chitosan and negatively charged sodium hyaluronate (HA) at balanced charge composition is investigated. These hydrogels exhibit strong tensile strain and strain rate dependence. They are elastic-like, independent of the strain rate at small strain, but exhibit plastic-like behavior above the yield point by showing a monotonous decrease of the stress. The cyclic tensile test demonstrates that these hydrogels exhibit small and quickly recoverable hysteresis in the elastic-like region, but large and partially recoverable hysteresis above the yield point. The stress relaxation experiment shows a plateau in the reduced stress followed by an abrupt fracture, and the time-to-failure decreases exponentially with increasing applied step-strain. Such elastic-to-plastic-like transformation of the biopolymer PEC gels is quite different from the behaviors of PEC hydrogels formed by oppositely charged vinyl-type synthetic polyelectrolytes due to the difference in flexibility, charge density, and ionic bond strength of these polymers.
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http://dx.doi.org/10.1021/acs.macromol.8b01658DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6449056PMC
November 2018

Ginsenoside Rg1 and Acori Graminei Rhizoma Attenuates Neuron Cell Apoptosis by Promoting the Expression of miR-873-5p in Alzheimer's Disease.

Neurochem Res 2018 Aug 20;43(8):1529-1538. Epub 2018 Jun 20.

Department of Traditional Chinese Medicine, Shandong Qianfoshan Hospital, 16766 Jingshi Road, Jinan, 250014, People's Republic of China.

Alzheimer's disease (AD) severely threatens human health in their old age, however the potential etiology underlying it is still unclear. Both Ginsenoside Rg1 (GRg1) and Acori graminei Rhizoma (AGR) are the traditional Chinese herbal drug, while their potential role in AD remains need further identification. Both SAMP1 and SAMP8 mice were employed as the control and AD mice. Morris water maze method was used to detect the cognitive function of the mice, TUNEL assay was performed to determine cell apoptosis. Real-time PCR and western blot were carried out to measure gene expression. The relationship between miR-873-5p and HMOX1 was determined using luciferase reporter assay. Comparing with SAMP1, the cognitive function was impaired and cell apoptosis was increased in SAMP8 mice. GRg1 + AGR treatment significantly attenuated the symptom of AD. The expression of miR-873-5p was decreased, while HMOX1 was increased in SAMP8 mice. GRg1 + AGR treatment significantly promoted the expression of miR-873-5p, but decreased HMOX1. MiR-873-5p targets HMOX1 to regulate its expression. Aβ1-42 stimulation decreased the expression of miR-873-5p, but increased HMOX1 in PC12 cells. GRg1 + AGR treatment reversed the effect of Aβ1-42, while miR-873-5p inhibitor abolished the effect of GRg1 + AGR. In vivo experiments confirmed the protect role of GRg1 + AGR in AD. GRg1 + AGR suppressed neuron cell apoptosis by regulating the expression of miR-873-5p in AD.
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http://dx.doi.org/10.1007/s11064-018-2567-yDOI Listing
August 2018

Amentoflavone Ameliorates Aβ-Induced Memory Deficits and Oxidative Stress in Cellular and Rat Model.

Neurochem Res 2018 Apr 6;43(4):857-868. Epub 2018 Feb 6.

Department of Traditional Chinese Medicine, Shandong Qianfoshan Hospital, 16766 Jingshi Road, Jinan, 250014, China.

Alzheimer's disease (AD), a progressive neurodegenerative disease of the central nervous system, is the most common cause of senile dementia. This study aimed to investigate whether amentoflavone (AF), a biflavonoid compound, could exert neuroprotective activities against AD. The AD model was established by the intracranial injection of amyloid-beta (Aβ) in rat models. The effect of AF on cognitive function was examined using the Morris water maze test. Cell survival and apoptosis in the hippocampal region in an animal model were detected using Nissl staining and a terminal deoxynucleotidyl transferased UTP nick-end labeling assay, respectively. The levels of oxidant enzymes were determined by enzyme-linked immunosorbent assay. Signaling molecule expressions were examined by western blotting. Our results showed that AF significantly attenuated Aβ-induced deficits in neurological functions as well as neuronal cell death and apoptosis in the hippocampal region. Moreover, our findings revealed that AF increased nuclear factor erythroid 2-related factor 2 (Nrf2) expression and translocation and activated AMP-activated protein kinase (AMPK) signaling. In a cellular model of AD established by exposing PC12 cells to Aβ, our results provided further evidence that the neuroprotective activities of AF were mediated by modulating Nrf2 through AMPK/glycogen synthase kinase 3 beta signaling. AF exerts a protective effect against Aβ-induced neurotoxcicity by inducing Nrf2 antioxidant pathways via AMPK signaling activation, which provided experimental evidence that AF might provide a clinical benefit to patients with AD.
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http://dx.doi.org/10.1007/s11064-018-2489-8DOI Listing
April 2018

Enhanced flame-retardant properties of cellulose fibers by incorporation of acid-resistant magnesium-oxide microcapsules.

Carbohydr Polym 2017 Nov 24;176:246-256. Epub 2017 Aug 24.

Collaborative Innovation Center for Marine Biomass Fibers, Materials and Textiles of Shandong Province, Institute of Marine Biobased Materials, College of Materials Science and Engineering, Qingdao University, Qingdao 266071, China.

Magnesium oxide (MgO) microcapsules were synthesized via in-situ emulsion polymerization as confirmed by Fourier transform infrared spectroscopy and scanning electron microscopy. Pure MgO and the MgO microcapsules were separately incorporated into cellulose fibers by blend wet spinning. Inductively coupled plasma-emission spectroscopy results revealed that cellulose fibers modified with the MgO microcapsules contained more Mg than those modified by pure MgO, indicating more acid resistance. The flammability and thermal degradation of modified cellulose fibers (cellulose-Mg fibers) were studied by calorimeter (CONE), thermogravimetry (TGA), and the determination of the limiting oxygen index (LOI). The minimal LOI value obtained for the cellulose-Mg fibers was 35, being much higher than that of the unmodified cellulose fiber (19). The heat release rate of the cellulose-Mg fibers was significantly lower than that of the non-doped ones. The TGA curves showed that the generated residues increased from 13.79% (cellulose fiber) to 30.26% (cellulose-Mg fiber).
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http://dx.doi.org/10.1016/j.carbpol.2017.08.096DOI Listing
November 2017

Influence of Hot Rolling and Heat Treatment on the Microstructural Evolution of β20C Titanium Alloy.

Materials (Basel) 2017 Sep 12;10(9). Epub 2017 Sep 12.

School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China.

The microstructural evolution and underlying mechanism of a new high strength, high toughness near β titanium alloy, β20C, during hot deformation, and heat treatment were studied qualitatively and quantitatively. It was found that dynamic recovery occurs mainly in β phase, while α phase undergoes both a dynamic recovery and continuous incomplete dynamic recrystallization with a fraction of high-angle grain boundaries (≥15°) of 21.1% under hot-rolling. Subsequently, α phase undergoes static recrystallization with an increasing fraction of high-angle grain boundaries (21.1%→60.7%) under annealing, while the grains are equiaxed with refined grain sizes of 1.63 µm observed from the rolling direction (RD) and 1.66 µm observed from the transverse direction (TD). Moreover, the average aspect ratio of the lamellar α phase was 2.44 observed from the RD and 3.12 observed from the TD after hot rolling, but decreased to 2.20 observed from the RD, and 2.53 observed from the TD after annealing. Furthermore, the strict Burgers' relationship between α and β phases changed after hot-rolling and remains the distortion, even after the static recrystallization process of α phase during annealing.
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http://dx.doi.org/10.3390/ma10091071DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5615725PMC
September 2017

INVESTIGATING DIFFERENCES IN BRAIN FUNCTIONAL NETWORKS USING HIERARCHICAL COVARIATE-ADJUSTED INDEPENDENT COMPONENT ANALYSIS.

Authors:
Ran Shi Ying Guo

Ann Appl Stat 2016 Dec 5;10(4):1930-1957. Epub 2017 Jan 5.

Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, 1518 Clifton Rd., Atlanta, Georgia 30322 USA.

Human brains perform tasks via complex functional networks consisting of separated brain regions. A popular approach to characterize brain functional networks in fMRI studies is independent component analysis (ICA), which is a powerful method to reconstruct latent source signals from their linear mixtures. In many fMRI studies, an important goal is to investigate how brain functional networks change according to specific clinical and demographic variabilities. Existing ICA methods, however, cannot directly incorporate covariate effects in ICA decomposition. Heuristic post-ICA analysis to address this need can be inaccurate and inefficient. In this paper, we propose a hierarchical covariate-adjusted ICA (hc-ICA) model that provides a formal statistical framework for estimating covariate effects and testing differences between brain functional networks. Our method provides a more reliable and powerful statistical tool for evaluating group differences in brain functional networks while appropriately controlling for potential confounding factors. We present an analytically tractable EM algorithm to obtain maximum likelihood estimates of our model. We also develop a subspace-based approximate EM that runs significantly faster while retaining high accuracy. To test the differences in functional networks, we introduce a voxel-wise approximate inference procedure which eliminates the need of computationally expensive covariance matrix estimation and inversion. We demonstrate the advantages of our methods over the existing method via simulation studies. We apply our method to an fMRI study to investigate differences in brain functional networks associated with post-traumatic stress disorder (PTSD).
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http://dx.doi.org/10.1214/16-AOAS946DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5375118PMC
December 2016

Influence of Na and Ca on flame retardancy, thermal degradation, and pyrolysis behavior of cellulose fibers.

Carbohydr Polym 2017 Feb 13;157:1594-1603. Epub 2016 Nov 13.

College of Materials Science and Engineering, Qingdao University, Qingdao 266071, China; Collaborative Innovation Center for Marine Biomass Fibers, Materials and Textiles of Shandong Province, Institute of Marine Biobased Materials, Qingdao University, Qingdao 266071, China. Electronic address:

Flame-retardant cellulose-Na and cellulose-Ca fibers were successfully synthesized by grafting Na and Ca onto cellulose fibers, and confirmed by FTIR. The combustion behavior of the fibers was assessed by the limiting oxygen index (LOI) and cone calorimeter (CONE). The maximum LOI values of cellulose-Na and cellulose-Ca fibers were 31 and 30, which are higher than that (19) of cellulose fibers. The CONE results showed that the values of heat-release rate and total heat release for cellulose-Na and cellulose-Ca fibers were significantly lower than those for cellulose fibers. The thermogravimetric analysis (TG) and differential thermogravimetric analysis (DTG) curves in the continuous and trigger modes showed that the cellulose-Na and cellulose-Ca fibers generated more residues than cellulose fibers. Thermogravimetric analysis-gas chromatography-mass spectrometry was used to detect the characteristic gases produced in the pyrolysis of cellulose-Na and cellulose-Ca fibers.
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http://dx.doi.org/10.1016/j.carbpol.2016.11.034DOI Listing
February 2017

Biochemical characterization of a novel L-asparaginase from Paenibacillus barengoltzii being suitable for acrylamide reduction in potato chips and mooncakes.

Int J Biol Macromol 2017 Mar 2;96:93-99. Epub 2016 Dec 2.

Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China. Electronic address:

A novel L-asparaginase gene (PbAsnase) from Paenibaeillus barengoltzii CAU904 was cloned and expressed in Escherichia coli. The L-asparaginase gene was 1011bp encoding 336 amino acids. Multiple sequence alignment of PbAsnase with other known L-asparaginases revealed that the enzyme showed high similarities with some Rhizobial-type L-asparaginases, sharing the highest identity of 32% with a characterized L-asparaginase from Rhizobium etli CFN 42, suggesting that it should be a novel L-asparaginase. The recombinant L-asparaginase (PbAsnase) was purified to homogeneity and biochemically characterized. The purified enzyme was optimally active at pH 8.5 and 45°C, respectively. It was stable within pH 5.5-10.0 and at temperatures below 55°C. PbAsnase exhibited strict substrate specificity towards L-asparagine (35.2U/mg), with K and V values of 3.6mM and 162.2μmol/min/mg, respectively, but displayed trace activity towards L-glutamine. Moreover, the application potential of PbAsnase on acrylamide migration in potato chips and mooncakes was evaluated. The pretreatment by PbAsnase significantly decreased the acrylamide contents in potato chips and mooncakes by 86% and 52%, respectively. The unique properties of PbAsnase may make it a good candidate in industries, especially in food safety.
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http://dx.doi.org/10.1016/j.ijbiomac.2016.11.115DOI Listing
March 2017

Mutational analysis and stability characterization of a novel esterase of lipolytic enzyme family VI from Shewanella sp.

Int J Biol Macromol 2016 Dec 12;93(Pt A):655-664. Epub 2016 Sep 12.

State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China. Electronic address:

Esterases are widely used in different industries. Here, a novel esterase, Esth, with low identity with previously reported esterases, was identified and characterized. The results showed that Esth was a cold-adapted esterase and retained 50% of its maximum activity at 0°C. Besides, Esth showed great activity and stability in high concentrations of NaCl. When treated with some organic solvents, detergents and metal ions, Esth showed high activity as well. The kcat/Km value of Esth was 29.5smM, suggesting that it has higher catalytic efficiency than all the previously reported esterases from the same family, lipolytic enzyme family VI. The structural modeling showed that changing Ala129 into Gly would form a new hydrogen bond between ser125 and Gly129 and make theα-helix longer, which might influence on the thermostability of enzymes (Kumar, 2000). To confirm this, the mutant Esth was obtained by site-directed mutagenesis. The result indicated that Esth retained over 70% of the activity versus 12% for Esth after incubation at 55°C for 120min, showed a nearly six fold increase when compared with wild type. Overall, Esth shows a potential application prospect in extreme conditions and the mutation research can provide some structural information about thermostable enzymes.
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http://dx.doi.org/10.1016/j.ijbiomac.2016.09.032DOI Listing
December 2016

Tanshinol suppresses endothelial cells apoptosis in mice with atherosclerosis via lncRNA TUG1 up-regulating the expression of miR-26a.

Am J Transl Res 2016 15;8(7):2981-91. Epub 2016 Jul 15.

Department of Traditional Chinese Medicine, Shandong Qianfoshan Hospital Jinan 250014, China.

Endothelial cell (EC) apoptosis is a crucial process for the development of atherosclerosis. Tanshinol is reported to protect vascular endothelia and attenuate the formation of atherosclerosis. However, the potential molecule mechanism of the protective role of tanshinol in atherosclerosis need to be further investigated. ApoE(-/-)mice were fed with a high-fat diet and treated with tanshinol to detect the effect of tanshinol on endothelial cells apoptosis with TUNEL staining assay. qRT-PCR and Western blot were performed to examine the expression of TUG1 and miR-26a in endothelial cells. RNA-binding protein immunoprecipitation assay was performed to verify the relationship between TUG1 and miR-26a. It has been shown that tanshinol reduced the aortic atherosclerotic lesion area in the entire aorta and aortic sinus in a concentration dependent manner, and suppressed the endothelial cells apoptosis in ApoE(-/-) mice. We further found that the mRNA level of TUG1 was reduced and the expression of miR-26a was up-regulated by tanshinol in endothelial cells. In addition, TUG1 down-regulated the expression of miR-26a in ECV304 cells. Finally, it was shown that overexpression of TUG1 removed the reversed effect of tanshinol on oxidized low-density lipoprotein (ox-LDL)-induced endothelial cells apoptosis. Taken together, our study reveals that tanshinol could attenuate the endothelial cells apoptosis in atherosclerotic ApoE(-/-) mice. Moreover, low TUG1 expression and high level of miR-26a are associated with the endothelial protecting effect of tanshinol.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4969434PMC
August 2016

Hepatitis B virus infection among pregnant women in Haiti: A cross-sectional serosurvey.

J Clin Virol 2016 Mar 28;76:66-71. Epub 2016 Jan 28.

US Centers for Disease Control and Prevention, Atlanta, GA,USA.

Background: Hepatitis B vaccine administered shortly after birth is highly effective in preventing mother to child transmission (MTCT) of infection. While hepatitis B vaccine was introduced in Haiti as part of a combined pentavalent vaccine in 2012, a birth dose is not yet included in the immunization schedule.

Objectives: Determine the seroprevalence of hepatitis B virus (HBV) infection among pregnant women to evaluate the risk of MTCT.

Study Design: We selected 1364 residual serum specimens collected during a 2012 human immunodeficiency virus (HIV) sentinel serosurvey among pregnant women attending antenatal care clinics. Haiti was stratified into two regions: West, which includes metropolitan Port-au-Prince, and non-West, which includes all other departments. We evaluated the association between demographic and socioeconomic characteristics and HIV infection with HBV infection.

Results: Of 1364 selected specimens, 1307 (96%) were available for testing. A total of 422 specimens (32.7%) tested positive for total anti-HBc (38.2% in West vs. 27% in non-West, p<0.001), and 33 specimens (2.5%) were HBsAg positive (2.1% in West vs. 3% in non-West, p=0.4). Of HBsAg positive specimens, 79% had detectable HBV DNA. Women aged 30 and older had more than double the odds of positive total anti-HBc than women aged 15-19 years (p<0.001). Women with secondary (adjusted odds ratio (aOR)=0.54; 95% CI: 0.36-0.81) and post-secondary education (aOR=0.40, 95% CI: 0.19-0.79) had lower odds of total anti-HBc positivity compared with women with no education. HIV-status was not associated with HBV infection.

Conclusions: Haiti has an intermediate endemicity of chronic HBV infection with high prevalence of positive HBV DNA among chronically infected women. Introduction of a universal birth dose of hepatitis B vaccine might help prevent perinatal HBV transmission.
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http://dx.doi.org/10.1016/j.jcv.2016.01.012DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5802338PMC
March 2016

Improve the flame retardancy of cellulose fibers by grafting zinc ion.

Carbohydr Polym 2016 Jan 11;136:121-7. Epub 2015 Sep 11.

Collaborative Innovation Center for Marine Biomass Fibers, Materials and Textiles of Shandong Province, Key Laboratory for Advanced Fiber Materials and Modern Textiles, College of Chemical Engineering, Qingdao University, Qingdao 266071, China. Electronic address:

Zinc ion as the only flame retardant of cellulose fibers was successfully grafted onto cellulose fibers. Grafting maleic anhydride onto cellulose fibers via homogeneous acylation reaction between N,N-dimethyl formamide (DMF) as the first step. Then, graft zinc ion onto the formed cellulose fibers was conducted with zinc carbonate. The resulting copolymers were characterized by FTIR. Flame retardancy and thermal degradation of zinc-ion-modified cellulose fibers (cellulose-Zn fibers) was investigated by limiting oxygen index (LOI), cone calorimeter (CONE), XRD, TG and SEM. Zinc ion could effectively improve flame retardancy and thermal degradation when its content increases up to 4.96 wt%.
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http://dx.doi.org/10.1016/j.carbpol.2015.09.026DOI Listing
January 2016

Semi-Automated Volumetric and Morphological Assessment of Glioblastoma Resection with Fluorescence-Guided Surgery.

Mol Imaging Biol 2016 06;18(3):454-62

Department of Neurosurgery, Emory University School of Medicine, 1701 Uppergate Drive, C5018, Atlanta, GA, 30322, USA.

Purpose: Glioblastoma (GBM) neurosurgical resection relies on contrast-enhanced MRI-based neuronavigation. However, it is well-known that infiltrating tumor extends beyond contrast enhancement. Fluorescence-guided surgery (FGS) using 5-aminolevulinic acid (5-ALA) was evaluated to improve extent of resection (EOR) of GBMs. Preoperative morphological tumor metrics were also assessed.

Procedures: Thirty patients from a phase II trial evaluating 5-ALA FGS in newly diagnosed GBM were assessed. Tumors were segmented preoperatively to assess morphological features as well as postoperatively to evaluate EOR and residual tumor volume (RTV).

Results: Median EOR and RTV were 94.3 % and 0.821 cm(3), respectively. Preoperative surface area to volume ratio and RTV were significantly associated with overall survival, even when controlling for the known survival confounders.

Conclusions: This study supports claims that 5-ALA FGS is helpful at decreasing tumor burden and prolonging survival in GBM. Moreover, morphological indices are shown to impact both resection and patient survival.
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http://dx.doi.org/10.1007/s11307-015-0900-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4862927PMC
June 2016

Visual Quality Evaluation of Image Object Segmentation: Subjective Assessment and Objective Measure.

IEEE Trans Image Process 2015 Dec 25;24(12):5033-45. Epub 2015 Aug 25.

A visual quality evaluation of image object segmentation as one member of the visual quality evaluation family has been studied over the years. Researchers aim at developing the objective measures that can evaluate the visual quality of object segmentation results in agreement with human quality judgments. It is also significant to construct a platform for evaluating the performance of the objective measures in order to analyze their pros and cons. In this paper, first, we present a novel subjective object segmentation visual quality database, in which a total of 255 segmentation results were evaluated by more than thirty human subjects. Then, we propose a novel full-reference objective measure for an object segmentation visual quality evaluation, which involves four human visual properties. Finally, our measure is compared with some state-of-the-art objective measures on our database. The experiment demonstrates that the proposed measure performs better in matching subjective judgments. Moreover, the database is available publicly for other researchers in the field to evaluate their measures.
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http://dx.doi.org/10.1109/TIP.2015.2473099DOI Listing
December 2015

Structural Brain Changes in Early-Onset Alzheimer's Disease Subjects Using the LONI Pipeline Environment.

J Neuroimaging 2015 Sep-Oct;25(5):728-37. Epub 2015 May 4.

Laboratory of Neuro Imaging, Institute for Neuroimaging and Informatics, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, 90032.

Background And Purpose: This study investigates 36 subjects aged 55-65 from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database to expand our knowledge of early-onset (EO) Alzheimer's Disease (EO-AD) using neuroimaging biomarkers.

Methods: Nine of the subjects had EO-AD, and 27 had EO mild cognitive impairment (EO-MCI). The structural ADNI data were parcellated using BrainParser, and the 15 most discriminating neuroimaging markers between the two cohorts were extracted using the Global Shape Analysis (GSA) Pipeline workflow. Then the Local Shape Analysis (LSA) Pipeline workflow was used to conduct local (per-vertex) post-hoc statistical analyses of the shape differences based on the participants' diagnoses (EO-MCI+EO-AD). Tensor-based Morphometry (TBM) and multivariate regression models were used to identify the significance of the structural brain differences based on the participants' diagnoses.

Results: The significant between-group regional differences using GSA were found in 15 neuroimaging markers. The results of the LSA analysis workflow were based on the subject diagnosis, age, years of education, apolipoprotein E (ε4), Mini-Mental State Examination, visiting times, and logical memory as regressors. All the variables had significant effects on the regional shape measures. Some of these effects survived the false discovery rate (FDR) correction. Similarly, the TBM analysis showed significant effects on the Jacobian displacement vector fields, but these effects were reduced after FDR correction.

Conclusions: These results may explain some of the differences between EO-AD and EO-MCI, and some of the characteristics of the EO cognitive impairment subjects.
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http://dx.doi.org/10.1111/jon.12252DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4537660PMC
November 2016

Gene interactions and structural brain change in early-onset Alzheimer's disease subjects using the pipeline environment.

Psychiatry Investig 2015 Jan 12;12(1):125-35. Epub 2015 Jan 12.

Laboratory of Neuro Imaging, Institute for Neuroimaging and Informatics, University of Southern California, Los Angeles, CA, USA.

Objective: This article investigates subjects aged 55 to 65 from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database to broaden our understanding of early-onset (EO) cognitive impairment using neuroimaging and genetics biomarkers.

Methods: Nine of the subjects had EO-AD (Alzheimer's disease) and 27 had EO-MCI (mild cognitive impairment). The 15 most important neuroimaging markers were extracted with the Global Shape Analysis (GSA) Pipeline workflow. The 20 most significant single nucleotide polymorphisms (SNPs) were chosen and were associated with specific neuroimaging biomarkers.

Results: We identified associations between the neuroimaging phenotypes and genotypes for a total of 36 subjects. Our results for all the subjects taken together showed the most significant associations between rs7718456 and L_hippocampus (volume), and between rs7718456 and R_hippocampus (volume). For the 27 MCI subjects, we found the most significant associations between rs6446443 and R_superior_frontal_gyrus (volume), and between rs17029131 and L_Precuneus (volume). For the nine AD subjects, we found the most significant associations between rs16964473 and L_rectus gyrus (surface area), and between rs12972537 and L_rectus_gyrus (surface area).

Conclusion: We observed significant correlations between the SNPs and the neuroimaging phenotypes in the 36 EO subjects in terms of neuroimaging genetics. However, larger sample sizes are needed to ensure that the effects will be detectable for a reasonable false-positive error rate using the GSA and Plink Pipeline workflows.
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http://dx.doi.org/10.4306/pi.2015.12.1.125DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4310910PMC
January 2015