Publications by authors named "Xu Fu"

80 Publications

Early satellite cell communication creates a permissive environment for long-term muscle growth.

iScience 2021 Apr 29;24(4):102372. Epub 2021 Mar 29.

The Center for Muscle Biology, University of Kentucky, Lexington, KY 40536, USA.

Using muscle stem cell (satellite cell)-specific extracellular vesicle (EV) tracking, satellite cell depletion, cell culture, and single-cell RNA sequencing, we show satellite cells communicate with other cells in skeletal muscle during mechanical overload. Early satellite cell EV communication primes the muscle milieu for proper long-term extracellular matrix (ECM) deposition and is sufficient to support sustained hypertrophy in adult mice, even in the absence of fusion to muscle fibers. Satellite cells modulate chemokine gene expression across cell types within the first few days of loading, and EV delivery of miR-206 to fibrogenic cells represses expression required for appropriate ECM remodeling. Late-stage communication from myogenic cells during loading is widespread but may be targeted toward endothelial cells. Satellite cells coordinate adaptation by influencing the phenotype of recipient cells, which extends our understanding of their role in muscle adaptation beyond regeneration and myonuclear donation.
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http://dx.doi.org/10.1016/j.isci.2021.102372DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8080523PMC
April 2021

Structural evolution of Si-based anode materials during the lithiation reaction.

Nanotechnology 2021 May 12;32(31). Epub 2021 May 12.

Institute of Rheological Mechanics, Xiangtan University, Hunan 411105, People's Republic of China.

Si-based materials have been intensively investigated as anode materials for Li-ion batteries. However, the structural evolution of the materials during the lithiation reaction is still unrevealed. In this paper, the structural parameters and mechanical properties of Si, SiO(0 <  < 2) and SiOduring the lithiation reaction are studied by first-principle calculation based on density functional theory. The relationship between the Li number and expansion coefficient, elastic constant, modulus, and Poisson's ratio is systematically calculated.
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http://dx.doi.org/10.1088/1361-6528/abfa54DOI Listing
May 2021

Nicotine induces morphological and functional changes in astrocytes via nicotinic receptor activity.

Glia 2021 Apr 14. Epub 2021 Apr 14.

Department of Chemistry, University of Kentucky, Lexington, Kentucky, USA.

Nicotine is a highly addictive compound present in tobacco, which causes the release of dopamine in different regions of the brain. Recent studies have shown that astrocytes express nicotinic acetylcholine receptors (nAChRs) and mediate calcium signaling. In this study, we examine the morphological and functional adaptations of astrocytes due to nicotine exposure. Utilizing a combination of fluorescence and atomic force microscopy, we show that nicotine-treated astrocytes exhibit time-dependent remodeling in the number and length of both proximal and fine processes. Blocking nAChR activity with an antagonist completely abolishes nicotine's influence on astrocyte morphology indicating that nicotine's action is mediated by these receptors. Functional studies show that 24-hr nicotine treatment induces higher levels of calcium activity in both the cell soma and the processes with a more substantial change observed in the processes. Nicotine does not induce reactive astrocytosis even at high concentrations (10 μM) as determined by cytokine release and glial fibrillary acidic protein expression. We designed tissue clearing experiments to test whether morphological changes occur in vivo using astrocyte specific Aldh1l1-tdTomato knock in mice. We find that nicotine induces a change in the volume of astrocytes in the prefrontal cortex, CA1 of the hippocampus, and the substantia nigra. These results indicate that nicotine directly alters the functional and morphological properties of astrocytes potentially contributing to the underlying mechanism of nicotine abuse.
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http://dx.doi.org/10.1002/glia.24011DOI Listing
April 2021

Photoluminescence Enhancement, Blinking Suppression, and Improved Biexciton Quantum Yield of Single Quantum Dots in Zero Mode Waveguides.

J Phys Chem Lett 2021 Apr 25;12(13):3303-3311. Epub 2021 Mar 25.

Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506, United States.

The capability of quantum dots to generate both single and multiexcitons can be harnessed for a wide variety of applications, including those that require high optical gain. Here, we use time-correlated photoluminescence (PL) spectroscopy to demonstrate that the isolation of single CdSeTe/ZnS core-shell, nanocrystal quantum dots (QDs) in Zero Mode Waveguides (ZMWs) leads to a significant modification in PL intensity, blinking dynamics, and biexciton behavior. QDs in aluminum ZMWs (AlZMWs) exhibited a 15-fold increase in biexciton emission, indicating a preferential enhancement of the biexciton radiative decay rate as compared to the single exciton rate. The increase in biexciton behavior was accompanied by a decrease in blinking events due to a shortening in the dark state residence time. These results indicate that plasmon mediated enhanced decay rates of QDs in AlZMWs lead to substantial changes in the photophysical properties of single quantum dots, including an increase in biexciton behavior.
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http://dx.doi.org/10.1021/acs.jpclett.1c00450DOI Listing
April 2021

Revealing compatibility mechanism of nanosilica in asphalt through molecular dynamics simulation.

J Mol Model 2021 Feb 11;27(3):81. Epub 2021 Feb 11.

College of Civil Engineering and Mechanics, Xiangtan University, Xiangtan, 411105, Hunan Province, China.

The compatibility between asphalt and nanosilica (nano-SiO) is critical to determine the performance of nano-SiO-modified asphalt. However, a comprehensive understanding of the compatibility behavior and mechanism of asphalt components and nano-SiO in the modified asphalt is still limited. In this study, the compatibility was revealed through molecular dynamics (MD) simulation. Virgin asphalt, nano-SiO-modified asphalt, and oxidation aged asphalt models produced with the COMPASS force field; meanwhile, the proposed models were validated by comparisons with reference data. The compatibility of asphalt and nano-SiO was analyzed by solubility and the Flory-Huggins parameters and interaction energy. Results show that the solubility parameters decreased with the increase of system temperature while increased with the asphalt's oxidation level increase. Meanwhile, the compatibility of the asphaltene, resin, and aromatic components in asphalt is better than the compatibility with saturates, which may be due to saturates being volatile; however, the compatibility of the nano-SiO and saturates is much better than those with asphaltene, resin, and aromatic components. The incorporation of nano-SiO alleviates the volatilization of saturates. The present results provide insights into the understanding of the compatibility behavior and mechanism of nano-SiO and asphalt components.
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http://dx.doi.org/10.1007/s00894-021-04697-1DOI Listing
February 2021

Genome-Wide Characterization of Lectin Receptor Kinases in L. and Their Responses to Infection.

Plants (Basel) 2021 Feb 8;10(2). Epub 2021 Feb 8.

Key Laboratory of Sugarcane Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Research Centre of National Sugarcane Engineering Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China.

Sugarcane is an important sugar and bioenergy ethanol crop, and the hyperploidy has led to stagnant progress in sugarcane genome decipherment, which also hindered the genome-wide analyses of versatile lectin receptor kinases (LecRKs). The published genome of , one of the two sugarcane ancestor species, enables us to study the characterization of LecRKs and their responses to sugarcane leaf blight (SLB) triggered by . A total of 429 allelic and non-allelic LecRKs, which were classified into evolved independently three types according to signal domains and phylogeny, were identified based on the genome. Regarding those closely related LecRKs in the phylogenetic tree, their motifs and exon architectures of representative L- and G-types were similar or identical. LecRKs showed an unequal distribution on chromosomes and more G-type tandem repeats may come from the gene expansion. Comparing the differentially expressed LecRKs (DELs) in response to SLB in sugarcane hybrid and ancestor species , we found that the DEL number in the shared gene sets was highly variable among each sugarcane accession, which indicated that the expression dynamics of LecRKs in response to SLB were quite different between hybrids and particularly between sugarcane hybrid and . In addition, C-type LecRKs may participate in metabolic processes of plant-pathogen interaction, mainly including pathogenicity and plant resistance, indicating their putative roles in sugarcane responses to SLB infection. The present study provides a basic reference and global insight into the further study and utilization of LecRKs in plants.
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http://dx.doi.org/10.3390/plants10020322DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7915762PMC
February 2021

Wireless Epidural Electrical Stimulation in Combination With Serotonin Agonists Improves Intraspinal Metabolism in Spinal Cord Injury Rats.

Neuromodulation 2021 Apr 30;24(3):416-426. Epub 2020 Dec 30.

Department of Neurosurgery, China International Neuroscience Institute (CHINA-INI), Xuanwu Hospital, Capital Medical University, Beijing, China.

Objectives: The combination of epidural electrical stimulation (EES) and serotonin agonists (5-HTA) effectively restores rhythmic lower-limb movements and improves intraspinal hemodynamics after spinal cord injury (SCI). Nonetheless, whether EES + 5-HTA improves intraspinal metabolism remains unclear. The present study aimed to evaluate the effects of EES + 5-HTA on intraspinal metabolism in SCI rats.

Materials And Methods: Wireless EES (WEES) implantation with complete T8 transection was performed in SCI rats. Electrodes were placed at the T12 and L2 vertebral levels. After rest for a week, the SCI rats received 11 weeks of WEES + 5-HTA treatment and treadmill training. WEES was switched off after each daily training. Locomotor function was evaluated by motion capture at week 12. Positron emission tomography-computed tomography was conducted to evaluate basal metabolism when WEES was switched off and assess task metabolism when WEES was switched on.

Results: With locomotor recovery after training for 11 weeks, WEES + 5-HTA conjointly improved basal metabolism (vs. each intervention alone; p < 0.05) and linearly modulated task metabolism in a frequency-dependent manner (R = 0.8901). Furthermore, 60 Hz of WEES was identified as the threshold for the extensive activation of the spinal cord's task metabolism below the transection plane (p < 0.05).

Conclusions: WEES + 5-HTA could conjointly restore basal metabolism to a healthy level and modulate task metabolism by adjusting the stimulation frequency.
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http://dx.doi.org/10.1111/ner.13344DOI Listing
April 2021

Sacral electroacupuncture as a treatment for urge urinary incontinence: a prospective case series.

Acupunct Med 2020 Dec 17:964528420968846. Epub 2020 Dec 17.

Department of Acupuncture and Moxibustion, The First Affiliated Hospital of Nanjing Medical University, Hangzhou, China.

Objective: To examine the impact of electroacupuncture (EA) at the 'four sacral points' on urge urinary incontinence (UUI).

Methods: Twenty-five patients diagnosed with UUI or urgency-predominant mixed urinary incontinence (MUI) were treated by EA at the 'four sacral points'. EA was performed in the sacrococcygeal region using disposable sterile 0.40-mm-diameter acupuncture needles that were either 100 or 125 mm in length. Treatments were delivered once every other day. Before and after treatment, a questionnaire measuring symptom severity and quality of life associated with UUI was administered.

Results: The median total score (interquartile range) from the severity of symptoms and the quality of life questionnaire (Q-score) of the participants was significantly reduced from 12 (7.5, 15) before treatment to 3 (0, 6) after 6 (6, 12) EA treatments. The Q-score of urgency-predominant MUI and UUI was 8 (5, 14.5) and 12.5 (11, 15), respectively, before treatment; after treatment these were reduced to 2 (0, 7.5) and 4.5 (2, 6), respectively. There was no statistically significant difference in the Q-score between urgency-predominant MUI and UUI before and after treatment. Upon treatment completion, seven patients (28%) were 'cured' (improvement rate 100%). Treatments were considered 'markedly effective' (improvement rate 75% to <100%) in four patients (16%), 'effective' (improvement rate 50% to <75%) in eight patients (32%), 'minimally effective' (improvement rate 25% to <50%) in three patients (12%), and 'ineffective' (improvement rate <25%) in three patients (12%). The overall success rate (comprising 'cured', 'markedly effective' and 'effective' categories) was 76%, and no adverse effects associated with acupuncture treatment were reported.

Conclusion: EA at the 'four sacral points' was associated with statistically significant improvements in UUI.
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http://dx.doi.org/10.1177/0964528420968846DOI Listing
December 2020

Tumor Microenvironment-"AND" Near-Infrared Light-Activated Coordination Polymer Nanoprodrug for On-Demand CO-Sensitized Synergistic Cancer Therapy.

Adv Healthc Mater 2021 04 11;10(7):e2001728. Epub 2020 Dec 11.

State Key Laboratory of Applied Organic Chemistry, Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, Lanzhou University, Gansu, Lanzhou, 730000, China.

Carbon monoxide (CO) as an emerging treatment holds great promise for inducing the apoptosis of cancer cells. Here coordination assembled strategy is first reported for synthesis of Cu(II)-flavone coordination polymer (NCu-FleCP) CO nanoprodrug that is stable in normal physiological conditions, and yet readily reduces to small size prodrug complex and releases CO on demand under glutathione (GSH) and near infrared (NIR) light. Specifically, after uptaking by cancer cells, local GSH attacked coordination bond within NCu-FleCP, resulting in the release of Cu(I) and free Fle. The CC bond of Fle is cleavage under NIR light to release CO for gas therapy, and Cu(I) reacts with local H O through Fenton like reaction to generate hydroxyl radicals ( OH) for chemodynamic therapy. Detailed in vitro and in vivo experiments demonstrate that the CO prodrug system in generating a sufficient quantity of CO and OH offers remarkable destructive effects against cancer cells without causing toxicity to surrounding normal tissues. The study provides a solid foundation to develop smart coordination polymer CO prodrugs with on-demand CO release, enhanced permeability and retention effect, and biodegradability for multimodal synergistic therapy.
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http://dx.doi.org/10.1002/adhm.202001728DOI Listing
April 2021

Fusion-Independent Satellite Cell Communication to Muscle Fibers During Load-Induced Hypertrophy.

Function (Oxf) 2020 6;1(1):zqaa009. Epub 2020 Jul 6.

The Center for Muscle Biology, University of Kentucky, Lexington, KY 40536, USA.

The "canonical" function of Pax7+ muscle stem cells (satellite cells) during hypertrophic growth of adult muscle fibers is myonuclear donation via fusion to support increased transcriptional output. In recent years, however, emerging evidence suggests that satellite cells play an important secretory role in promoting load-mediated growth. Utilizing genetically modified mouse models of delayed satellite cell fusion and extracellular vesicle (EV) tracking, we provide evidence for satellite cell communication to muscle fibers during hypertrophy. Myogenic progenitor cell-EV-mediated communication to myotubes influences extracellular matrix (ECM)-related gene expression, which is congruent with overload experiments involving satellite cell depletion, as well as analyses. Satellite cell-derived EVs can transfer a Cre-induced, cytoplasmic-localized fluorescent reporter to muscle cells as well as microRNAs that regulate ECM genes such as matrix metalloproteinase 9 (), which may facilitate growth. Delayed satellite cell fusion did not limit long-term load-induced muscle hypertrophy indicating that early fusion-independent communication from satellite cells to muscle fibers is an underappreciated aspect of satellite cell biology. We cannot exclude the possibility that satellite cell-mediated myonuclear accretion is necessary to maintain prolonged growth, specifically in the later phases of adaptation, but these data collectively highlight how EV delivery from satellite cells can directly contribute to mechanical load-induced muscle fiber hypertrophy, independent of cell fusion to the fiber.
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http://dx.doi.org/10.1093/function/zqaa009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7448100PMC
July 2020

Real-Time Monitoring Method for Layered Compaction Quality of Loess Subgrade Based on Hydraulic Compactor Reinforcement.

Sensors (Basel) 2020 Jul 31;20(15). Epub 2020 Jul 31.

School of Science, Xi'an University of Architecture and Technology, Xi'an 710055, China.

Hydraulic compactor is an efficient reinforcement machine for loess subgrade. However, it is difficult to control the layered compaction quality of the subgrade. This research presents a real-time layered compactness monitoring method for hydraulic compactor reinforcement of subgrade in loess areas. The hydraulic force coefficient is first introduced, and the dynamic response model of the hydraulic rammer and soil is established. The relationship between the acceleration of the hydraulic rammer and the compactness of subgrade is then obtained based on the collision theory in elastic half space. A full-scale test using a hydraulic compactor to reinforce loess subgrade was also carried out. Results show that the hydraulic compactor obtains the effective influence depth for the reinforcement of loess subgrade. Within the effective reinforcement depth, the relationship between the peak acceleration of the rammer and the layered compactness of subgrade can be well fitted by a quadratic function model. The layered compactness of the subgrade and the working state of the hydraulic compactor can then be remotely monitored at a mobile terminal in real time. Furthermore, the monitoring technology was applied to Huangling-Yan'an Expressway in China, significantly improving the accuracy and efficiency of real-time monitoring of the layered compactness of subgrade in the loess area.
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http://dx.doi.org/10.3390/s20154288DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7435419PMC
July 2020

Single-Molecule Detection of Nanoparticles for Multiphoton Fluorescence Correlation Spectroscopy to Quantify Cerebral Blood Flow.

Nano Lett 2020 08 8;20(8):6135-6141. Epub 2020 Jul 8.

Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506, United States.

We present the application of multiphoton fluorescence correlation spectroscopy (FCS) of fluorescent nanoparticles for the measurement of cerebral blood flow with excellent spatial and temporal resolution. Through the detection of single nanoparticles within the complex vessel architecture of a live mouse, this new approach enables the quantification of nanoparticle dynamics occurring within the vasculature along with simultaneous measurements of blood flow properties in the brain. In addition to providing high resolution blood flow measurements, this approach enables real-time quantification of nanoparticle concentration, degradation, and transport. This method is capable of quantifying flow rates at each pixel with submicron resolution to enable monitoring of dynamic changes in flow rates in response to changes in the animal's physiological condition. Scanning the excitation beam using FCS provides pixel by pixel mapping of flow rates with subvessel resolution across capillaries 300 μm deep in the brains of mice.
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http://dx.doi.org/10.1021/acs.nanolett.0c02280DOI Listing
August 2020

Few-moded ultralarge mode area chalcogenide photonic crystal fiber for mid-infrared high power applications.

Opt Express 2020 May;28(11):16658-16672

We demonstrate a novel few-moded ultralarge mode area chalcogenide glass photonic crystal fiber for mid-infrared high power applications. The numerical simulation indicates that the fiber has ultralarge mode areas of ∼10500 µm and ∼12000 µm for the fundamental mode LP and the lowest higher-order mode LP, respectively. Dual-moded operation is confirmed experimentally at 2 µm, in good agreement with the numerical simulation. By selectively launching technique, low bending loss of 0.7 dB/m, equivalent to 0.55 dB/turn, has been observed in the fiber with a small bending radius of ∼12 cm, indicating excellent bending resistance of the few-moded fiber with such a large mode area. The fiber has been demonstrated to sustain an incident power density up to 150 kW/cm under 2-µm CW laser irradiation, showing the potential of the fiber for high-power applications in mid-infrared.
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http://dx.doi.org/10.1364/OE.389507DOI Listing
May 2020

Does influent C/N ratio affect pollutant removal and greenhouse gas emission in wastewater ecological soil infiltration systems with/without intermittent aeration?

Water Sci Technol 2020 Feb;81(4):668-678

College of Life Science, Shenyang Normal University, Shenyang 110034, China E-mail:

Wastewater ecological soil infiltration system (WESIS) is a land treatment technology for decentralized wastewater treatment that has been applied all over the world. In this study, the pollutant removal, emission of greenhouse gases (GHGs) and functional gene abundances with different influent C/N ratios were evaluated in WESISs with/without intermittent aeration. Intermittent aeration and influent C/N ratio affect pollutant removal and GHG emission. Increased influent C/N ratio led to high total nitrogen (TN) removal, low CH and NO emission in the aerated WESIS, which was different from the non-aerated WESIS. High average removal efficiencies of chemical oxygen demand (COD) (94.8%), NH-N (95.1%), TN (91.2%), total phosphorus (TP) (91.1%) and low emission rates for CH (27.2 mg/(m d)) and NO (10.5 mg/(m d)) were achieved with an influent C/N ratio of 12:1 in the aerated WESIS. Intermittent aeration enhanced the abundances of bacterial 16S rRNA, amoA, nxrA, narG, napA, nirK, nirS, qnorB, nosZ genes and decreased the abundances of the mcrA gene, which are involved in pollutant removal and GHG emission. Intermittent aeration would be an effective alternative to achieving high pollutant removal and low CH and NO emission in high influent C/N ratio wastewater treatment.
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http://dx.doi.org/10.2166/wst.2020.141DOI Listing
February 2020

Novel, Self-Distinguished, Dual Stimulus-Responsive Therapeutic Nanoplatform for Intracellular On-Demand Drug Release.

Mol Pharm 2020 07 5;17(7):2435-2450. Epub 2020 Jun 5.

Department of Biomaterials, College of Materials, Research Center of Biomedical Engineering of Xiamen & Key Laboratory of Biomedical Engineering of Fujian Province & Fujian Provincial Key Laboratory for Soft Functional Materials Research, Xiamen University, Xiamen 361005, China.

On-demand drug release nanoplatforms are promising alternative strategies for enhancing the therapeutic effect of cancer chemotherapy. However, these nanoplatforms still have many drawbacks including rapid blood clearance, nontargeted specificity, and a lack of immune escape function. Even worse, they are also hindered the dosage-limiting toxicity of traditional chemotherapeutic drugs. Herein, both dual-functional mannose (enhances the antitumor activity of chemotherapeutic drugs and exhibits an innate affinity against the lectin receptor) and amphiphilic d-α-tocopheryl polyethylene glycol 1000 succinate were selected to be covalently linked a redox-responsive monothioether linkage. The synthesized self-distinguished polymer (TSM), as a structural motif, can be self-assembled into nanoparticles (TSM NPs) in an aqueous solution, in which doxorubicin (DOX) is loaded by weak interactions (TSM-DOX NPs). These TSM-DOX NPs can provide targeted, on-demand drug release under dual stimuli from lysosomal acidity and glutathione (GSH). In addition, TSM-DOX NPs can be self-distinguished tumor cells and specifically self-distinguished from the tumor site . Further and research consistently demonstrated that TSM-DOX NPs display highly synergistic chemotherapeutic effects. Taken together, the data show that the self-distinguished GSH-responsive polymer TSM has the potential to load various therapeutic agents.
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http://dx.doi.org/10.1021/acs.molpharmaceut.0c00165DOI Listing
July 2020

Association Between Lifelong Premature Ejaculation and Polymorphism of Tryptophan Hydroxylase 2 Gene in the Han Population.

Sex Med 2020 Jun 10;8(2):223-229. Epub 2020 Mar 10.

Department of Urology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.

Introduction: Premature ejaculation (PE) is widely regarded as one of the most common sexual dysfunctions in men. The neurobiogenesis of PE is complex and involves the serotoninergic (5-HT) system.

Aim: In this study, we investigated whether polymorphisms in the tryptophan hydroxylase 2 (TPH2) gene were associated with lifelong PE (LPE).

Methods: A total of 121 men diagnosed with LPE were recruited from our outpatient clinics and 94 healthy controls from the health examination center. Intravaginal ejaculation latency time (IELT) was measured using a stopwatch. The PE diagnostic tool (PEDT) data were collected at the same time. All subjects with LPE and healthy controls were genotyped for polymorphisms in the TPH2 gene. Allele and genotype frequencies of single-nucleotide polymorphisms (SNPs) were compared between the patients and controls.

Main Outcome Measure: The main outcome measures are IELT and PEDT to diagnose LPE. The association of LPE with TPH2 gene polymorphisms in these areas was investigated.

Results: The IELT, PEDT scores, and education levels in the LPE group were significantly different from those in the control group. Statistically significant differences were found in the SNPs of SNV019 and rs4290270. The frequencies of the G allele and G/A genotype of SNV019 were significantly higher in the patients with LPE than in the controls (P = .045 and .037, respectively). The A allele and A/A genotype of rs4290270 were more frequent in the patients with LPE than in the controls (P = .037 and .049, respectively). In the dominant model of inheritance, the SNV019 polymorphism in the patients with LPE was significantly different from that in the controls (odds ratio [95% confidence interval] = 2.936 [1.066-8.084], P = .037). In men with LPE, there was no statistically significant association between genotype and median IELT.

Conclusion: The SNPs SNV019 and rs4290270 of the TPH2 gene seemed to be associated with LPE in the Han population. Men with the A allele of SNV019 or the T allele of rs4290270 may be less likely to suffer from LPE. Fu X, Zhang X, Jiang T, et al. Association Between Lifelong Premature Ejaculation and Polymorphism of Tryptophan Hydroxylase 2 Gene in the Han Population. Sex Med 2020;8:223-229.
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http://dx.doi.org/10.1016/j.esxm.2020.02.004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7261684PMC
June 2020

High-throughput fluorescence correlation spectroscopy enables analysis of surface components of cell-derived vesicles.

Anal Bioanal Chem 2020 Apr 7;412(11):2589-2597. Epub 2020 Mar 7.

Department of Chemistry, University of Kentucky, 161 Jacobs Science Building, Lexington, KY, 40506, USA.

Extracellular vesicles (EVs) and cell-derived vesicles (CDVs), generated by fragmenting cellular membranes, have both been explored as therapeutic delivery vehicles. Surface proteins on these vesicles are of great importance as they are characteristic to the cell of origin and modulate vesicle interactions with target cells. Here, we introduced a high-throughput fluorescence correlation spectroscopy (ht-FCS) approach capable of characterizing vesicle surface proteins across a large number of samples. We used automated screening and acquisition of FCS data to profile surface proteins of cell-derived vesicles with high fidelity based on changes in diffusion time upon antibody-vesicle interactions. We characterized vesicles generated from 4 cell types using antibodies for known exosome biomarkers. The ht-FCS technique presented here offers the capability to screen EVs or cell-derived vesicles against a library of surface markers or to screen a library of cell-derived vesicles for a specific identifying marker at a high speed.
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http://dx.doi.org/10.1007/s00216-020-02485-zDOI Listing
April 2020

Overexpression of Nrf2 Protects Against Lipopolysaccharide and Cerulein-Induced Pancreatitis In Vitro and In Vivo.

Pancreas 2020 03;49(3):420-428

From the Department of Emergency Intensive Care Unit and Laboratory of Emergency Medicine, Lanzhou University Second Hospital, Lanzhou, China.

Objectives: In this study, we focused on the function of nuclear factor E2-related factor 2 (Nrf2) in acute pancreatitis (AP), which has been shown to have protective effects in gliomas, hepatocytes, and astrocytes.

Methods: Acute pancreatitis cell line and animal model were induced by administration of lipopolysaccharide and cerulein into the cell supernatant or intraperitoneal injection. Oxidative stress status was evaluated by measuring the level of amylase, C-reactive protein, malondialdehyde, superoxide dismutase, and myeloperoxidase. Morphological alterations in the pancreas were evaluated by hematoxylin-eosin staining, the wet-to-dry weight ratio, and the pathology injury scores. Western blot, reverse transcription-polymerase chain reaction, and immunofluorescence staining were performed to analyze the expression of Nrf2, Heme oxygenase 1, and NAD(P)H: quinone oxidoreductase 1.

Results: Overexpression of Nrf2 inhibits oxidative stress and inflammatory responses by inducting the expression of superoxide dismutase as well as reducing the level of amylase, malondialdehyde, and myeloperoxidase in the AR42J rat pancreatic acinar cells in AP. Importantly, overexpression of Nrf2 displayed the same protective effect in vivo. Data from an AP rat model showed that Nrf2 could relieve pancreatic damage.

Conclusions: These results indicated that Nrf2 has a protective role in lipopolysaccharide and cerulein-induced cytotoxicity, providing potential therapeutic strategies for the treatment of AP.
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http://dx.doi.org/10.1097/MPA.0000000000001501DOI Listing
March 2020

SSD1 modifies phenotypes of Elongator mutants.

Curr Genet 2020 Jun 27;66(3):481-485. Epub 2019 Nov 27.

Västerbotten County Council/Department of Odontology, Umeå University, 901 87, Umeå, Sweden.

The translational decoding properties of tRNAs are influenced by post-transcriptional modification of nucleosides in their anticodon region. The Elongator complex promotes the first step in the formation of 5-methoxycarbonylmethyl (mcm), 5-methoxycarbonylhydroxymethyl (mchm), and 5-carbamoylmethyl (ncm) groups on wobble uridine residues in eukaryotic cytosolic tRNAs. Elongator mutants in yeast, worms, plants, mice, and humans not only show a tRNA modification defect, but also a diverse range of additional phenotypes. Even though the phenotypes are almost certainly caused by the reduced functionality of the hypomodified tRNAs in translation, the basis for specific phenotypes is not well understood. Here, we discuss the recent finding that the phenotypes of Saccharomyces cerevisiae Elongator mutants are modulated by the genetic background. This background-effect is largely due to the allelic variation at the SSD1 locus, which encodes an mRNA-binding protein involved in post-transcriptional regulation of gene expression. A nonsense ssd1 allele is found in several wild-type laboratory strains and the presence of this allele aggravates the stress-induced phenotypes of Elongator mutants. Moreover, other phenotypes, such as the histone acetylation and telomeric gene silencing defects, are dependent on the mutant ssd1 allele. Thus, SSD1 is a genetic modifier of the phenotypes of Elongator-deficient yeast cells.
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http://dx.doi.org/10.1007/s00294-019-01048-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7198479PMC
June 2020

Predictive Factors and Microbial Spectrum for Infectious Complications after Hepatectomy with Cholangiojejunostomy in Perihilar Cholangiocarcinoma.

Surg Infect (Larchmt) 2020 Apr 11;21(3):275-283. Epub 2019 Nov 11.

Department of Hepatobiliary and Pancreatic Surgery, Nanjing University Medical School Affiliated Nanjing Drum Tower Hospital, Nanjing, Jiangsu, P.R. China.

Despite advances in surgical techniques and peri-operative management, post-operative infectious complications still are common after perihilar cholangiocarcinoma (PHCC). This study investigated the predictive factors and microbial spectrum for infections after hepatectomy with cholangiojejunostomy performed to treat PHCC. A total of 70 consecutive patients, who underwent hepatectomy with cholangiojejunostomy by the same surgeons at a tertiary referral medical center between September 2010 and January 2019, were enrolled. Clinical data were reviewed for multivariable analysis to find independent risk factors for infectious complications. Microorganisms isolated from bile and infection sites were counted to explore the microbial spectrum. A total of 43 patients (61.4%) suffered post-operative infections (33 with surgical site infection [SSI], four with bacteremia, three with pneumonia, 10 with cholangitis, and two with fungus infectious stomatitis), and 28 of them (65.1%) had a positive bile culture. Four independent risk factors were identified: male sex (odds ratio [OR] 12.737; 95% confidence interval [CI] 2.298-70.611; p = 0.004), red blood cell (RBC) count <3.8 × 10/L (OR 5.085; 95% CI 1.279-20.211; p = 0.021), total cholesterol (TC) <2.90 mmol/L (OR 5.715; 95% CI 1.534-21.299; p = 0.009), and serum Na >145 mmol/L (OR 10.387; 95% CI 1.559-69.201; p = 0.016) on post-operative day (POD) 1. A total of 217 and 196 microorganisms were cultured from 311 and 627 specimens, respectively, collected from pre-/intra-operative bile and possible infection sites. , , and were the most common findings of bile culture. The first five organisms most frequently isolated from infection sites were and . A total of 18 patients (64.3%) had at least one species isolated from infection sites that had appeared in a previous bile culture. Male sex, erythrocytopenia, hypocholesterolemia, and hypernatremia on POD 1 are independent risk factors for infectious complications. For patients without positive bile cultures, third-generation cephalosporins could be considered as the prophylactic antibiotic. It is important to monitor the pathogens throughout the hospital stay.
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http://dx.doi.org/10.1089/sur.2019.199DOI Listing
April 2020

Behavior of an Advanced Bolted Shear Connector in Prefabricated Steel-Concrete Composite Beams.

Materials (Basel) 2019 Sep 12;12(18). Epub 2019 Sep 12.

College of Civil Engineering and Mechanics, Xiangtan University, Xiangtan 411105, China.

The high-strength bolt shear connector in prefabricated concrete slab has advantages in applications as it reduces time during the construction of steel-concrete composite building structures and bridges. In this research, an innovative and advanced bolt shear connector in steel-concrete composite structures is proposed. To investigate the fundamental mechanical behavior and the damage form, 22 static push-off tests were conducted with consideration of different bolt dimensions, the reserved hole constraint condition, and the dimension of slab holes. A finite element (FE) model was established and verified by using test results, and then the model was utilized to investigate the influence of concrete strength, bolt dimension, yield strength, bolt pretension, as well as length-to-diameter ratio of high strength bolts on the performances of shear connectors. On the basis of FE simulation and test results, new design formulas for the calculation of shear resistance behavior were proposed, and comparisons were made with current standards, including AISC, EN 1994-1-1, GB 50017-2017, and relevant references, to check the calculation efficiency. It is confirmed that the proposed equation is in better agreement with the experimental results.
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http://dx.doi.org/10.3390/ma12182958DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6766210PMC
September 2019

SSD1 suppresses phenotypes induced by the lack of Elongator-dependent tRNA modifications.

PLoS Genet 2019 08 29;15(8):e1008117. Epub 2019 Aug 29.

Department of Molecular Biology, Umeå University, Umeå, Sweden.

The Elongator complex promotes formation of 5-methoxycarbonylmethyl (mcm5) and 5-carbamoylmethyl (ncm5) side-chains on uridines at the wobble position of cytosolic eukaryotic tRNAs. In all eukaryotic organisms tested to date, the inactivation of Elongator not only leads to the lack of mcm5/ncm5 groups in tRNAs, but also a wide variety of additional phenotypes. Although the phenotypes are most likely caused by a translational defect induced by reduced functionality of the hypomodified tRNAs, the mechanism(s) underlying individual phenotypes are poorly understood. In this study, we show that the genetic background modulates the phenotypes induced by the lack of mcm5/ncm5 groups in Saccharomyces cerevisiae. We show that the stress-induced growth defects of Elongator mutants are stronger in the W303 than in the closely related S288C genetic background and that the phenotypic differences are caused by the known polymorphism at the locus for the mRNA binding protein Ssd1. Moreover, the mutant ssd1 allele found in W303 cells is required for the reported histone H3 acetylation and telomeric gene silencing defects of Elongator mutants. The difference at the SSD1 locus also partially explains why the simultaneous lack of mcm5 and 2-thio groups at wobble uridines is lethal in the W303 but not in the S288C background. Collectively, our results demonstrate that the SSD1 locus modulates phenotypes induced by the lack of Elongator-dependent tRNA modifications.
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http://dx.doi.org/10.1371/journal.pgen.1008117DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6738719PMC
August 2019

Cell-Derived Vesicles for in Vitro and in Vivo Targeted Therapeutic Delivery.

ACS Omega 2019 Jul 24;4(7):12657-12664. Epub 2019 Jul 24.

Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506, United States.

Efficient delivery of therapeutics across the cell membrane to the interior of the cell remains a challenge both in vitro and in vivo. Here, we demonstrate that vesicles derived from cellular membranes can be efficiently loaded with cargo that can then be delivered to the interior of the cell. These vesicles demonstrated cell-targeting specificity as well as the ability to deliver a wide range of different cargos. We utilized this approach to deliver both lipophilic and hydrophilic cargos including therapeutics and DNA in vitro. We further demonstrated in vivo targeting and delivery using fluorescently labeled vesicles to target tumor xenografts in an animal. Cell-derived vesicles can be generated in high yields and are easily loaded with a variety of cargos. The ability of these vesicles to specifically target the same cell type from which they originated provides an efficient means of delivering cargo, such as therapeutics, both in vitro and in vivo.
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http://dx.doi.org/10.1021/acsomega.9b01353DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6681979PMC
July 2019

Comparative Analysis of two Sugarcane Ancestors and based on Complete Chloroplast Genome Sequences and Photosynthetic Ability in Cold Stress.

Int J Mol Sci 2019 Aug 5;20(15). Epub 2019 Aug 5.

Key Laboratory of Sugarcane Biology and Genetic Breeding, Fujian Agriculture and Forestry University, Fuzhou 350002, China.

Polyploid with complex genomes hindered the progress of sugarcane improvement, while their chloroplast genomes are much smaller and simpler. Chloroplast (cp), the vital organelle, is the site of plant photosynthesis, which also evolves other functions, such as tolerance to environmental stresses. In this study, the cp genome of two sugarcane ancestors and were sequenced, and genome comparative analysis between these two species was carried out, together with the photosynthetic ability. The length is 141,187 bp for and that is 7 bp longer than , with the same GC content (38.44%) and annotated gene number (134), 13 with introns among them. There is a typical tetrad structure, including LSC, SSC, IRb and IRa. Of them, LSC and IRa/IRb are 18 bp longer and 6 bp shorter than those in (83,047 bp and 22,795 bp), respectively, while the size of SSC is same (12,544 bp). Five genes exhibit contraction and expansion at the IR junctions, but only one gene with 29 bp expansion at the border of IRb/SSC. Nucleotide diversity (Pi) based on sliding window analysis showed that the single copy and noncoding regions were more divergent than IR- and coding regions, and the variant hotspots , , , and in the LSC and in the SSC regions were detected, and with the highest divergent value of 0.01500. Genetic distances of 65 protein genes vary from 0.00000 to 0.00288 between two species, and the selective pressure on them indicated that only was subjected to positive selection, while more genes including , , , , , , and were subjected to purifying or very strong purifying selection. There are larger number of codons in than that in , while both species have obvious codon preference and the codons with highest-(AUG) and lowest frequency (AUA) are same. Whilst, the most abundant amino acid is leucine in both and , with number of 2175 (10.88% of total) and 2228 (10.90% of total) codons, respectively, and the lowest number is cysteine, with only 221 (1.105%) and 224 (1.096%), respectively. Protein collinearity analysis showed the high collinearity though several divergences were present in cp genomes, and identification of simple sequence repeats (SSRs) were included in this study. In addition, in order to compare cold tolerance and explore the expanding function of this environmental stress, the chlorophyll relative content (SPAD) and chlorophyll fluorescence Fv/Fm were measured. The significantly higher SPAD were observed in than those in no matter what the control conditions, exposure to low temperature or during recovery, and so was for Fv/Fm under exposure to low temperature, together with higher level of SPAD in in each measurement. Aforementioned results suggest much stronger photosynthetic ability and cold tolerance in . Our findings build a foundation to investigate the biological mechanism of two sugarcane ancestor chloroplasts and retrieve reliable molecular resources for phylogenetic and evolutionary studies, and will be conducive to genetic improvement of photosynthetic ability and cold resistance in modern sugarcane.
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http://dx.doi.org/10.3390/ijms20153828DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6696253PMC
August 2019

Transcriptome profiling of the low-salinity stress responses in the gills of the juvenile Pseudopleuronectes yokohamae.

Comp Biochem Physiol Part D Genomics Proteomics 2019 12 26;32:100612. Epub 2019 Jul 26.

Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, Dalian, 116023, China. Electronic address:

Salinity is an important environmental factor that affects the life cycle of fish, including their growth, development and reproduction. The marbled flounder, Pseudopleuronectes yokohamae, is an important economic resource and serves as a good model to investigate osmoregulation, as it can adapt to a wide range of salinity levels. However, the lack of genomic resources for this species has hampered the understanding of the mechanisms underlying its salinity tolerance. In this study, RNA-Seq analysis was conducted to identify genes related to salinity adaptation and osmotic regulation in the gill tissue of marbled flounder exposed to different concentrations of environmental salinity (6 and 30 ppt). After de novo assembly, 19,265 genes were annotated by the Nr database. A comparison of expression between the two salinity groups revealed 673 differentially expressed genes, of which 180 were upregulated and 493 were downregulated in the low salinity group relative to the high salinity group. The related molecular biological processes were explored from several important perspectives, and potential functions were determined by enrichment analyses, including those of metabolites in ion transportation, energy metabolism and protein synthesis, and immune responses. This study is the first transcriptomic study conducted on marbled flounder, and it revealed many novel sequences for further biological analyses. In addition, the candidate genes identified in the gene expression analysis provided insights into responses to salinity change and molecular mechanisms underlying osmoregulation in the gills of marbled flounder.
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http://dx.doi.org/10.1016/j.cbd.2019.100612DOI Listing
December 2019

Brain Region Specific Single-Molecule Fluorescence Imaging.

Anal Chem 2019 08 24;91(15):10125-10131. Epub 2019 Jul 24.

Department of Chemistry , University of Kentucky , Lexington , Kentucky 40506 , United States.

We developed an approach utilizing nanoscale vesicles extracted from brain regions combined with single molecule imaging to monitor how an animal's physiological condition regulates the dynamics of protein distributions in different brain regions. This method was used to determine the effect of nicotine on the distribution of receptor stoichiometry in different mouse brain regions. Nicotine-induced upregulation of α4β2 nicotinic acetylcholine receptors (nAChRs) is associated with changes in their expression, trafficking, and stoichiometry. The structural assembly of nAChRs has been quantified in cell culture based systems using single molecule techniques. However, these methods are not capable of quantifying biomolecule assembly that takes place in a live animal. Both nicotine-induced upregulation and changes in nAChR stoichiometry differ across brain regions. Our single molecule approach revealed that nicotine acts differentially across brain regions to alter assembly in response to exposure and withdrawal.
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http://dx.doi.org/10.1021/acs.analchem.9b02133DOI Listing
August 2019

Nanoscale Mechanical Properties and Indentation Recovery of PI@GO Composites Measured Using AFM.

Polymers (Basel) 2018 Sep 13;10(9). Epub 2018 Sep 13.

College of Civil Engineering and Mechanics, Xiangtan University, Xiangtan 411105, China.

Polyimide@graphene oxide (PI@GO) composites were prepared by way of a simple solution blending method. The nanoscale hardness and Young's modulus of the composites were measured using nanoindentation based on atomic force microscopy (AFM). A nanoscale hardness of ~0.65 GPa and an elastic modulus of ~6.5 GPa were reached with a load of ~55 μN. The indentation recovery on the surface of PI@GO was evaluated. The results show that relatively low GO content can remarkably improve the nanoscale mechanical properties of PI.
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http://dx.doi.org/10.3390/polym10091020DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6403599PMC
September 2018

Phase segregation due to ion migration in all-inorganic mixed-halide perovskite nanocrystals.

Nat Commun 2019 03 6;10(1):1088. Epub 2019 Mar 6.

National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China.

Semiconductor mixed-halide perovskites featured with a tunable energy bandgap are ideal candidates for light absorbers in tandem solar cells as well as fluorescent materials in light-emitting diodes and nanoscale lasers. These device advancements are currently hindered by the light-induced phase segregation effect, whereby ion migration would yield smaller-bandgap domains with red-shifted photoluminescence. Here we show that upon laser excitation all-inorganic mixed-halide nanocrystals unexpectedly exhibit a blue shift in the photoluminescence peak that can revert back in the dark, thus depicting the processes of ion migration out of and back to the originally excited nanocrystals. Interestingly, this reversible photoluminescence shift can also be induced by electrical biasing of mixed-halide nanocrystals without the injection of charge carriers. The above findings suggest that it is the local electric field that breaks the ionic bonds in mixed-halide nanocrystals, which could be a universal origin for light-induced phase segregation observed in other mixed-halide perovskite materials.
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http://dx.doi.org/10.1038/s41467-019-09047-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6403211PMC
March 2019

Effects of effluent organic matters on endocrine disrupting chemical removal by ultrafiltration and ozonation in synthetic secondary effluent.

J Environ Sci (China) 2019 Feb 29;76:57-64. Epub 2018 Mar 29.

Civil Engineering Department, North China Institute of Aerospace Engineering, Langfang 065000, China.

Endocrine disrupting chemicals (EDCs) in the secondary effluent discharged from wastewater treatment plants are of great concern when water reuse is intended. Ozonation and ultrafiltration (UF) are powerful technologies reported to eliminate EDCs. Due to the importance of effluent organic matters (EfOMs) in secondary effluent, the effects of three kinds of EfOM on the treatment of five EDCs using ozonation and UF were investigated. The three kinds of EfOM studied were humic acid sodium salt (NaAH), bovine serum albumin (BSA) and sodium alginate (NaAg); and the five EDCs were estrone, 17β-estradiol, estriol, 17α-ethynyl estradiol and bisphenol A. The results showed that EfOM accelerated the decay rate of ozone and inhibited the degradation efficiency of EDCs by ozonation in the order NaAH>BSA>NaAg. The ultraviolet absorbance at 280nm (UVA) has potential for use as a surrogate indicator to assess EDC removal via ozonation without conducting difficult EDC analyses. When the decline in UVA exceeded 18%, the five EDCs had been completely removed. The UF behavior of NaAH, BSA and NaAg was found to follow the cake filtration law. The fouling potential of EfOM followed the order NaAg>NaAH>BSA; while EfOM on the membrane surface enhanced EDC removal in the order NaAH>BSA>NaAg. The mean retention rate of the membrane was increased by 24%, 10% and 8%, respectively. The properties of EDCs and EfOM cakes both influenced the EDC removal rates due to adsorption, size exclusion and charge attraction.
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http://dx.doi.org/10.1016/j.jes.2018.03.025DOI Listing
February 2019

Temperature Effect on the Mechanical Properties of Electrospun PU Nanofibers.

Nanoscale Res Lett 2018 Nov 29;13(1):384. Epub 2018 Nov 29.

College of Civil Engineering and Mechanics, Xiangtan University, Xiangtan, 411105, Hunan, China.

Polyurethane (PU) nanofibers were prepared from electrospun method. Atomic force microscopy (AFM) was employed to characterize the mechanical properties of electrospun PU nanofibers. The impact of temperature on the mechanical behavior of PU nanofibers was studied using three-point bending test based on AFM. A Young's modulus of ~ 25 GPa was obtained for PU nanofibers with diameter at ~ 150 nm at room temperature. With decrease in nanofiber's diameter, the increasing Young's modulus can be due to the surface tension effect. The Young's modulus of the PU nanofiber decreased linearly while the fibrous morphology was maintained with the increase of temperature.
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http://dx.doi.org/10.1186/s11671-018-2801-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6261907PMC
November 2018