Publications by authors named "Shan Zou"

55 Publications

Attribution of changes in the trend and temporal non-uniformity of extreme precipitation events in Central Asia.

Sci Rep 2021 Jul 22;11(1):15032. Epub 2021 Jul 22.

State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Ürümqi, 830011, China.

Extreme precipitation events exhibit an increasing trend for both the frequency and magnitude on global and regional scales and it has already proven the impact of man-made global warming on the extreme precipitation amplification. Based on the observed datasets and global climate model (GCM) output, this study has evaluated the impact from anthropogenic forcing on the trend and temporal non-uniformity (i.e. increase in unevenness or disparity) of the precipitation amounts (PRCPTOT), extremes (R95p and RX5day) and intensity (SDII) in Central Asia (CA) from 1961 to 2005. Results indicate that radiative forcing changes, mainly driven by human activities, have significantly augmented the extreme precipitation indices in CA. The median trend with the influence of anthropogenic activities for the PRCPTOT, SDII, R95p and RX5day amounted to 2.19 mm/decade, 0.019 mm/decade, 1.39 mm/decade and 0.21 mm/decade during the study period, respectively. A statistically insignificant decrease in non-uniformity was noticed for the PRCPTOT, SDII and RX5day in Central CA (CCA) and Western CA (WCA), while Eastern CA (ECA) was the only region with a statistically significant increase in non-uniformity of the PRCPTOT, SDII, R95p and RX5day by 4.22%, 3.98%, 3.73% and 3.97%, respectively from 1961 to 2005 due to anthropogenic forcing. These results reflect the difference in various regions regarding the impact of anthropogenic forcing on the non-uniformity of extreme precipitation events in CA, which might help to fully understand the role of anthropogenic forcing in the changes of the precipitation extremes in CA and contribute to the development of water resource management strategies.
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http://dx.doi.org/10.1038/s41598-021-94486-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8298420PMC
July 2021

Impact of inappropriate empirical antibiotic treatment on clinical outcomes of urinary tract infections caused by Escherichia coli: a retrospective cohort study.

J Glob Antimicrob Resist 2021 Jun 9;26:148-153. Epub 2021 Jun 9.

Jiangxi Provincial Key Laboratory of Medicine, Clinical Laboratory of the Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, People's Republic of China. Electronic address:

Objectives: We aimed to determine the clinical impact of inappropriate empirical antibiotic treatment (IEAT) compared with appropriate empirical antibiotic treatment (AEAT) in hospitalised patients with urinary tract infections (UTIs) caused by Escherichia coli (E. coli).

Methods: This retrospective cohort study included adult patients with a primary diagnosis of UTI who were treated with empirical antibiotics at a tertiary hospital in southern China over a 2-year period. Clinical data of patients who received IEAT were compared with those of patients receiving AEAT. We used multivariable logistic regression to identify the predictors for receiving IEAT and the risk factors affecting clinical outcomes.

Results: A total of 213 patients were enrolled (median age, 61 years), of whom 103 (48.4%) received IEAT. IEAT was associated with empirical use of fluoroquinolones, male sex and age-adjusted Charlson comorbidity index (aCCI) score >6. Hospital length of stay (LOS) was longer for patients who received IEAT than for those who received AEAT (13.6 ± 8.6 days vs. 10.8 ± 7.9 days; P = 0.008). IEAT was an independent risk factor for longer LOS along with aCCI score ≥2, lung disease and cardiac disease.

Conclusion: Empirical use of fluoroquinolones for UTIs should be avoided, especially in male patients with aCCI score >6. Improved empirical antimicrobial therapy may have a beneficial impact in reducing bacterial resistance and healthcare costs by decreasing the LOS. Therefore, interventions to promote in-depth antibiotic stewardship programmes in China are needed.
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http://dx.doi.org/10.1016/j.jgar.2021.05.016DOI Listing
June 2021

Influence of bound dodecanoic acid on the reconstitution of albumin nanoparticles from a lyophilized state.

Sci Rep 2021 Feb 26;11(1):4768. Epub 2021 Feb 26.

Centre for Biologics Evaluation, Biologics and Genetic Therapies Directorate, Health Canada, 251 Sir Frederick Banting Driveway, Ottawa, ON, K1A 0K9, Canada.

The development of reference standards for nanoparticle sizing allows for cross laboratory studies and effective transfer of particle sizing methodology. To facilitate this, these reference standards must be stable upon long-term storage. Here, we examine factors that influence the properties of cross-linked albumin nanoparticles, fabricated with an ethanol desolvation method, when reconstituted from a lyophilized state. We demonstrate, with nanoparticle tracking analysis, no significant changes in mean particle diameter upon reconstitution of albumin nanoparticles fabricated with bovine serum albumin loaded with dodecanoic acid, when compared to nanoparticles fabricated with a fatty acid-free BSA. We attribute this stability to the modulation of nanoparticle charge-charge interactions at dodecanoic acid specific binding locations. Furthermore, we demonstrate this in a lyophilized state over six months when stored at - 80 °C. We also show that the reconstitution process is readily transferable between technicians and laboratories and further confirm our finding with dynamic light scattering analysis.
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http://dx.doi.org/10.1038/s41598-021-84131-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7910568PMC
February 2021

In situ rolling circle amplification surface modifications to improve E. coli O157:H7 capturing performances for rapid and sensitive microfluidic detection applications.

Anal Chim Acta 2021 Mar 22;1150:338229. Epub 2021 Jan 22.

Department of Chemical and Biological Engineering, University of Ottawa, 161 Louis Pasteur, Ottawa, ON, K1N 6N5, Canada. Electronic address:

We investigated the application of rolling circle amplification (RCA) to modify microfluidic channels for potential sensitive detection applications. To this end, a novel in situ capturing RCA (cRCA) strategy was used to modify the inner surfaces of microfluidic channels with cRCA products that featured repeating tandem capturing aptamers specific for E. coli O157:H7 cells. We showed that the in situ cRCA reaction modified microfluidic channels demonstrated significantly enhanced capturing efficiency in a wide range of flow rates when compared with the unit-aptamer approach. We demonstrated for the first time that microfluidic surfaces modified with the in situ cRCA products showed peak capturing performances both in terms of target capturing efficiency and specificity, and this was likely due to unexpected base-pairing that resulted in altered secondary structures of the capturing aptamers. Our data suggest that the in situ cRCA surface modification is a promising strategy to improve capturing performances in microfluidic devices in sensitive detection applications that also require high throughput. However, cRCA reaction conditions, particularly reaction time and concentrations of initial circular template, must be carefully investigated before the potentials of the in situ cRCA surface modification approach can be fully realized.
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http://dx.doi.org/10.1016/j.aca.2021.338229DOI Listing
March 2021

Anti-leukemia effect associated with down-regulated CD47 and up-regulated calreticulin by stimulated macrophages in co-culture.

Cancer Immunol Immunother 2021 Mar 29;70(3):787-801. Epub 2020 Sep 29.

Metrology Research Centre, National Research Council Canada, 100 Sussex Drive, Ottawa, ON, K1A 0R6, Canada.

CD47 is over-expressed in Acute Myeloid Leukemia (AML) and functions as an inhibitory signal, suppressing phagocytosis by binding to signal regulatory protein α (SIRPα) on the surface of macrophages. Inhibition of CD47 restores the immune surveillance of AML cells. However, the inhibition of CD47 in AML by activated macrophages and the subsequent effects on different immune response parameters are not fully understood. Here, we demonstrate the use of a distinct co-culture method to inhibit CD47 and therefore eliminate AML cells by macrophages in vitro. Human chemically induced THP-1 macrophages were activated using different concentrations of lipopolysaccharide (LPS) and co-culturing with three AML cancer cell lines (HL-60, NB4, and THP-1), respectively, as well as normal human peripheral blood mononuclear cells (PBMC). CD47 inhibition was observed in and selective to AML but not observed in normal PBMC. Additionally, calreticulin (CRT) levels were elevated in the same cell lines simultaneously, after co-culturing with activated human macrophages, but not elevated in normal cells. We also show that the activated macrophages secreted high levels of cytokines, including IL-12p70, IL-6, and TNF-α, consistent with the elimination of AML by macrophages. Our study reveals the potential of this model for screening new drugs against AML and the possibility of using human macrophages in AML treatment in the future.
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http://dx.doi.org/10.1007/s00262-020-02728-zDOI Listing
March 2021

Probing arsenic trioxide (ATO) treated leukemia cell elasticities using atomic force microscopy.

Anal Methods 2020 10;12(39):4734-4741

Metrology Research Centre, National Research Council of Canada, Ottawa, K1A 0R6, Canada. and Department of Chemistry, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada.

Conventional analytical techniques allow for the diagnosis of leukemia, blood and bone marrow cancers, as well as their classification into the different subtypes. However, a better understanding of the cancer treatment through cell apoptosis staging is still required. Evaluation of the timeline and responses of acute promyelocytic leukemia (APL) cells to the arsenic trioxide (ATO) treatment is essential for determining the oral dosage in leukemia prognosis. Here, an Atomic Force Microscopy (AFM) indentation approach has been used to evaluate the mechanical responses of cellular responses of APL cells to ATO treatment, alongside well-established cell viability assays, as a novel method to determine the impact of drugs. In addition, cell morphology was quantified to monitor cellular apoptosis. Viability, morphology and elasticity changes of NB4 cells (derived from Human APL patients) were correlated to different time courses of the ATO treatments. Unveiling the relationships among structural, morphological and nanomechanical properties in response to ATO drug treatment promises to pave the way for novel diagnostic tools for drug screening and for a better understanding of the specific physical and biological effects of drugs on diseased cells.
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http://dx.doi.org/10.1039/d0ay01017kDOI Listing
October 2020

Developing a dual-RCA microfluidic platform for sensitive E. coli O157:H7 whole-cell detections.

Anal Chim Acta 2020 Aug 6;1127:79-88. Epub 2020 Jul 6.

Department of Chemical and Biological Engineering, University of Ottawa, 161 Louis Pasteur, Ottawa, ON, K1N 6N5, Canada; Ottawa-Carleton Institute of Biomedical Engineering, University of Ottawa, Ottawa, ON, K1N 6N5, Canada. Electronic address:

Aptamer based microfluidic platforms have been developed rapidly in recent years, and strategies to improve detection sensitivities of such platforms have attracted a significant amount of attention. To achieve whole cell sensitive detections by microfluidic devices, a new dual-rolling circle amplification (RCA) detection approach is presented in this study. This dual-RCA approach includes a capturing RCA (cRCA) reaction that is designed to modify microfluidic channel surfaces with long tandem repeating aptamers (i.e. poly-aptamers) to effectively capture target E. coli O157:H7 cells. We demonstrate that this poly-aptamers modified microchannels capture 3-fold more target cells in comparison with microchannels modified with mono-aptamers against the target cells. In addition, signalling RCA (sRCA) is employed in the dual-RCA design to further enhance detection signals. Our results show that the detection signals are enhanced by up to 50 times by sRCA when compared with those with single fluorescence probes. Furthermore, by combing both the cRCA and the sRCA in one dual-RCA detection system, we demonstrate that the detection signals can be significantly enhanced by ∼250-fold. We also show that E. coli O157:H7 detections with the dual-RCA approach can be used in different food matrices, including orange juice and milk where the limit of detection of 80 cells/mL is achieved. In conclusion, this microfluidic device in combination with a dual-RCA to enhance both target capturing and detection signals is a simple and promising approach to sensitive whole-cell detections for food safety inspections.
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http://dx.doi.org/10.1016/j.aca.2020.06.046DOI Listing
August 2020

Effect of ABO Blood Groups on the Response to Warfarin.

Am J Med Sci 2020 07 10;360(1):50-54. Epub 2020 Apr 10.

Department of Cardiology, the First Affiliated Hospital, Shantou University Medical College, Shantou, Guangdong, China. Electronic address:

Background: Numerous studies have demonstrated that patients with non-O blood groups have a higher risk for venous thromboembolism than those with the O blood group. However, the effect of ABO blood groups on warfarin dose requirements in patients receiving anticoagulation in the Chinese Han population remains unknown. This study aimed to investigate the influence of ABO blood groups on warfarin dose requirements in a Chinese Han population.

Material And Methods: A retrospective study was conducted in the First Affiliated Hospital of Shantou University Medical College in South China. Three hundred and fifty-eight patients with a confirmed diagnosis of deep vein thrombosis or atrial fibrillation were included. The frequency of blood groups and warfarin dose requirements were determined.

Results: Of 358 patients with deep vein thrombosis or atrial fibrillation, 111 patients had blood group A (31.01%), 104 patients had blood group B (29.05%), 20 patients had blood group AB (5.59%) and 123 patients had blood group O (34.36%). The patients in the O blood group had lower warfarin dose requirements than those in the A, B and AB blood groups.

Conclusions: Our study showed that patients with non-O blood groups require higher doses of warfarin.
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http://dx.doi.org/10.1016/j.amjms.2020.03.022DOI Listing
July 2020

Conformational Order in Aggregated rra-P3HT as an Indicator of Quality of Boron Nitride Nanotubes.

J Phys Chem Lett 2020 May 11;11(10):4179-4185. Epub 2020 May 11.

We report on investigation, by correlated polarized excitation fluorescence microscopy (PEFM) and atomic force microscopy (AFM) imaging, of the conformational order of regiorandom poly(3-hexyl-thiophene) (rra-P3HT) aggregated on two boron nitride nanotube (BNNT) materials (BNNT-2 and BNNT-3) processed by different purification methods. rra-P3HT photoluminescence excited by linearly polarized light shows polarization direction-dependent intensity with a modulation depth, , generally >0.5 for rra-P3HT on nanotubes and <0.5 for rra-P3HT on nontubular impurities. PEFM-measured modulation depth value distributions can be decomposed into two components, one corresponding to ordered rra-P3HT on nanotubes and the other to disordered rra-P3HT on impurities. The nanotube component peaks at = 0.64 and 0.70 and comprises 60% and 78% of the normalized distribution for rra-P3HT on BNNT-2 and BNNT-3, respectively, indicating higher quality and higher fraction of nanotubes in the latter material. The method can be integrated in a material development platform to monitor production and purification progress.
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http://dx.doi.org/10.1021/acs.jpclett.0c01023DOI Listing
May 2020

Cellular Metrology: Scoping for a Value Proposition in Extra- and Intracellular Measurements.

Front Bioeng Biotechnol 2019 14;7:456. Epub 2020 Jan 14.

National Physical Laboratory, Teddington, United Kingdom.

The symptomatic irreproducibility of data in biomedicine and biotechnology prompts the need for higher order measurements of cells in their native and near-native environments. Such measurements may support the adoption of new technologies as well as the development of research programs across different sectors including healthcare and clinic, environmental control and national security. With an increasing demand for reliable cell-based products and services, cellular metrology is poised to help address current and emerging measurement challenges faced by end-users. However, metrological foundations in cell analysis remain sparse and significant advances are necessary to keep pace with the needs of modern medicine and industry. Herein we discuss a role of metrology in cell and cell-related R&D activities to underpin growing international measurement capabilities. Relevant measurands are outlined and the lack of reference methods and materials, particularly those based on functional cell responses in native environments, is highlighted. The status quo and current challenges in cellular measurements are discussed in the light of metrological traceability in cell analysis and applications (e.g., a functional cell count). An emphasis is made on the consistency of measurement results independent of the analytical platform used, high confidence in data quality vs. quantity, scale of measurements and issues of building infrastructure for end-users.
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http://dx.doi.org/10.3389/fbioe.2019.00456DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6970939PMC
January 2020

Prognostic value of circulating lymphocyte B and plasma immunoglobulin M on septic shock and sepsis: a systematic review and meta-analysis.

Am J Transl Res 2019 15;11(12):7223-7232. Epub 2019 Dec 15.

Adult Intensive Care Unit, The University of Hong Kong-Shenzhen Hospital Shenzhen, China.

Objective: Normal B lymphocyte function and antibody secretion during inflammation can provide critical protection for the host. We aimed to synthesize existing evidence to explore whether circulating B cells and plasma immunoglobulin M (IgM) levels were associated with survival during sepsis.

Methods: PubMed, Embase, ISI Web of Knowledge, Cochrane Central Register of Controlled Trials were systematically searched. Studies with data on circulating B cells and plasma IgM levels within the initial 24 hours after sepsis onset were selected.

Results: A total of 11 studies were qualified for inclusion in this systematic review and meta-analysis with a total of 829 patients with sepsis and/or septic shock. Number of circulating B cells was similar between septic patients and health controls (SMD = -1.81, 95% CI: -4.15, 0.54; P = 0.13, I = 99%), while it was significantly reduced in sepsis survivors versus sepsis non-survivors (SMD = -0.60, 95% CI: -0.87, -0.32; P < 0.0001, I = 0%). Concentration of plasma IgM level was significantly decreased in septic patients as compared with healthy controls. Also, the plasma IgM level was significantly lower in sepsis survivors versus sepsis non-survivors.

Conclusions: A poor prognostic survival outcome was observed for patients with decreased circulating B cells as well as IgM levels within the initial 24 h after sepsis onset.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6943463PMC
December 2019

Author Correction: Efficient electron transfer across hydrogen bond interfaces by proton-coupled and -uncoupled pathways.

Nat Commun 2019 Jun 4;10(1):2525. Epub 2019 Jun 4.

Department of Chemistry, Jinan University, 601 Huang-Pu Avenue West, 510632, Guangzhou, China.

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/s41467-019-10580-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6547680PMC
June 2019

Neutrophil-to-lymphocyte and platelet-to-lymphocyte ratio in Chinese Han population from Chaoshan region in South China.

BMC Cardiovasc Disord 2019 05 27;19(1):125. Epub 2019 May 27.

Department of Cardiology, the First Affiliated Hospital, Shantou University Medical College, Shantou, 515041, Guangdong, China.

Background: Neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are assumed to be prognostic factors in many diseases such as inflammatory diseases, cardiovascular diseases and cancer. However, NLR and PLR are race specific, it is important to determine the reference values of NLR and PLR in different races. The study aimed to investigate the reference range of NLR and PLR in Chinese Han population from Chaoshan region in South China.

Methods: A retrospective study was conducted in the First Affiliated Hospital of Shantou University Medical College in South China. Five thousand healthy adults aged 20-69 years were included. NLR and PLR were determined.

Results: Of 5000 healthy adults, 2500 men and 2500 women were included. The mean NLR and PLR across all ages for men and women were 1.59 ± 0.59, 92.88 ± 28.70, 1.62 ± 0.64 and 108.02 ± 32.99, respectively. The 95% reference range of NLR in normal male and female are 0.43~2.75 and 0.37~2.87, PLR are 36.63~149.13 and 43.36~172.68, respectively. The female had a higher NLR at age 30~49 than the male while the NLR at age 60~69 was higher in male than in female. The PLR was higher in female than in male.

Conclusion: The study provides reference data on NLR and PLR from different age and sex groups in South China. NLR and PLR varied with age and sex.
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http://dx.doi.org/10.1186/s12872-019-1110-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6537433PMC
May 2019

Author Correction: Efficient electron transfer across hydrogen bond interfaces by proton-coupled and -uncoupled pathways.

Nat Commun 2019 May 2;10(1):2081. Epub 2019 May 2.

Department of Chemistry, Jinan University, 601 Huang-Pu Avenue West, 510632, Guangzhou, China.

The original version of this Article contained errors in the symbols displayed in the eighteenth sentence of the third paragraph of the 'Determination of H and k data for the Mo dimers' section of the Results, and the third sentence of the Discussion. This has been corrected in both the PDF and HTML versions of the Article.
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http://dx.doi.org/10.1038/s41467-019-10193-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6497637PMC
May 2019

Efficient electron transfer across hydrogen bond interfaces by proton-coupled and -uncoupled pathways.

Nat Commun 2019 04 4;10(1):1531. Epub 2019 Apr 4.

Department of Chemistry, Jinan University, 601 Huang-Pu Avenue West, 510632, Guangzhou, China.

Thermal electron transfer through hydrogen bonds remains largely unexplored. Here we report the study of electron transfer through amide-amide hydrogen bonded interfaces in mixed-valence complexes with covalently bonded Mo units as the electron donor and acceptor. The rate constants for electron transfer through the dual hydrogen bonds across a distance of 12.5 Å are on the order of ∼ 10 s, as determined by optical analysis based on Marcus-Hush theory and simulation of ν(NH) vibrational band broadening, with the electron transfer efficiencies comparable to that of π conjugated bridges. This work demonstrates that electron transfer across a hydrogen bond may proceed via the known proton-coupled pathway, as well as an overlooked proton-uncoupled pathway that does not involve proton transfer. A mechanistic switch between the two pathways can be achieved by manipulation of the strengths of electronic coupling and hydrogen bonding. The knowledge of the non-proton coupled pathway has shed light on charge and energy transport in biological systems.
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http://dx.doi.org/10.1038/s41467-019-09392-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6449364PMC
April 2019

Characterization of Size and Aggregation for Cellulose Nanocrystal Dispersions Separated by Asymmetrical-Flow Field-Flow Fractionation.

Cellulose (Lond) 2019 ;27(4)

National Research Council Canada, Ottawa, ON, K1A 0R6, Canada.

Cellulose nanocrystals (CNCs) derived from various types of cellulose biomass have significant potential for applications that take advantage of their availability from renewable natural resources and their high mechanical strength, biocompatibility and ease of modification. However, their high polydispersity and irregular rod-like shape present challenges for the quantitative dimensional determinations that are required for quality control of CNC production processes. Here we have fractionated a CNC certified reference material using a previously reported asymmetrical-flow field-flow fractionation (AF4) method and characterized selected fractions by atomic force microscopy (AFM) and transmission electron microscopy. This work was aimed at addressing discrepancies in length between fractionated and unfractionated CNC and obtaining less polydisperse samples with fewer aggregates to facilitate microscopy dimensional measurements. The results demonstrate that early fractions obtained from an analytical scale AF4 separation contain predominantly individual CNCs. The number of laterally aggregated "dimers" and clusters containing 3 or more particles increases with increasing fraction number. Size analysis of individual particles by AFM for the early fractions demonstrates that the measured CNC length increases with increasing fraction number, in good agreement with the rod length calculated from the AF4 multi-angle light scattering data. The ability to minimize aggregation and polydispersity for CNC samples has important implications for correlating data from different sizing methods.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7676384PMC
January 2019

Mapping Bridge Conformational Effects on Electronic Coupling in Mo-Mo Mixed-Valence Systems.

Inorg Chem 2018 Jun 29;57(12):7455-7467. Epub 2018 May 29.

Department of Chemistry , Jinan University , 601 Huang-Pu Avenue West , Guangzhou 510632 , China.

The large bridging ligand 9,10-anthracenedicarboxylate and its thiolated derivatives have been employed to assemble two dimolybdenum complex units and develop three Mo dimers, [Mo(DAniF)](μ-9,10-OCCHCO), [Mo(DAniF)](μ-9,10-OSCCHCOS), and [Mo(DAniF)](μ-9,10-SCCHCS) (DAniF = N, N'-di( p-anisyl)formamidinate), for the study of conformation dependence of the electronic coupling between the two Mo centers. These compounds feature a large deviation of the central anthracene ring from the plane defined by the Mo-Mo bond vectors, with the torsion angles (ϕ = 50-76°) increasing as the chelating atoms of the bridging ligand vary from O to S. Consequently, the corresponding mixed-valence complexes do not exhibit characteristic intervalence charge transfer absorptions in the near-IR spectra, in contrast to the phenylene and naphthalene analogues, from which these systems are assigned to the Class I in Robin-Day's scheme. Together with the phenylene and naphthalene series, the nine total mixed-valence complexes in three series complete a transition from the electronically uncoupled Class I to the strongly coupled Class II-III borderline via moderately coupled Class II and permit a systematic mapping of the bridge conformation effects on electronic coupling. Density functional theory calculations show that the HOMO-LUMO energy gap, corresponding to the metal (δ) to ligand (π*) transition energy, and the magnitude of HOMO-HOMO-1 splitting in energy are linearly related to cos ϕ. Therefore, our experimental and theoretical results concur to indicate that the coupling strength decreases in the order of the bridging units: phenylene > naphthalene > anthracene, which verifies the through-bond superexchange mechanism for electronic coupling and electron transfer.
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http://dx.doi.org/10.1021/acs.inorgchem.8b01056DOI Listing
June 2018

Identification of long-term trends and seasonality in high-frequency water quality data from the Yangtze River basin, China.

PLoS One 2018 21;13(2):e0188889. Epub 2018 Feb 21.

Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, China.

Comprehensive understanding of the long-term trends and seasonality of water quality is important for controlling water pollution. This study focuses on spatio-temporal distributions, long-term trends, and seasonality of water quality in the Yangtze River basin using a combination of the seasonal Mann-Kendall test and time-series decomposition. The used weekly water quality data were from 17 environmental stations for the period January 2004 to December 2015. Results show gradual improvement in water quality during this period in the Yangtze River basin and greater improvement in the Uppermost Yangtze River basin. The larger cities, with high GDP and population density, experienced relatively higher pollution levels due to discharge of industrial and household wastewater. There are higher pollution levels in Xiang and Gan River basins, as indicated by higher NH4-N and CODMn concentrations measured at the stations within these basins. Significant trends in water quality were identified for the 2004-2015 period. Operations of the three Gorges Reservoir (TGR) enhanced pH fluctuations and possibly attenuated CODMn, and NH4-N transportation. Finally, seasonal cycles of varying strength were detected for time-series of pollutants in river discharge. Seasonal patterns in pH indicate that maxima appear in winter, and minima in summer, with the opposite true for CODMn. Accurate understanding of long-term trends and seasonality are necessary goals of water quality monitoring system efforts and the analysis methods described here provide essential information for effectively controlling water pollution.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0188889PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5821306PMC
March 2018

R-Wave Peak Time at Lead II in Adults With Ventricular Premature Beats, Bundle Branch Block and Left Anterior Fascicular Block.

Am J Med Sci 2018 01 1;355(1):44-47. Epub 2017 Sep 1.

Department of Cardiology, The First Affiliated Hospital, Shantou University Medical College, Shantou, Guangdong, China. Electronic address:

Background: Recently, the R-wave peak time (RWPT) at lead II was reported to be a helpful and simple tool for differentiating wide QRS complex tachycardias with a RWPT ≥ 50ms for ventricular tachycardia diagnosis. Our previous study showed that the duration of RWPT at lead II in adults was ≈29ms. However, the effects of ventricular premature beats (VPBs), bundle branch block (BBB) or left anterior fascicular block (LAFB) on RWPT at lead II remain unknown.

Methods: The study was conducted in the First Affiliated Hospital of Shantou University Medical College in Southern China. Adults with VPBs, BBB or LAFB were included. RWPT at lead II was determined.

Results: Compared with the control groups, the right BBB, LAFB, RWPT were longer in groups with left BBB and VPBs. Compared with the group with left BBB, the group with VPBs had a significantly longer RWPT at lead II (54.20 ± 18.52 versus 84.76 ± 16.38ms, P < 0.01).

Conclusion: Our study showed that there is a significant difference in the RWPT at lead II between groups with left BBB, ventricular premature beat, right BBB and LAFB. A RWPT of 50ms may be optimal to differentiate between ventricular tachycardia and supraventricular tachycardia with right left BBB and LAFB, but not with left BBB.
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http://dx.doi.org/10.1016/j.amjms.2017.08.017DOI Listing
January 2018

Temperature induced lipid membrane restructuring and changes in nanomechanics.

Biochim Biophys Acta Biomembr 2018 Mar 15;1860(3):700-709. Epub 2017 Dec 15.

Measurement Science and Standards, National Research Council Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada; Department of Chemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada. Electronic address:

The naturally occurring milk sphingomyelin is of particular interest owing to its complex composition and involvement in the formation of the milk fat globule membrane (MFGM). Knowledge of membrane organization and nanomechanical stability has proved to be crucial in understanding their properties and functions. In this work, two model membrane systems composed of 1, 2 dioleoyl-sn-glycero-3-phosphocholine (DOPC), egg sphingomyelin (egg-SM) and cholesterol, and DOPC, milk sphingomyelin (milk-SM) and cholesterol were exposed to both RT and 10°C. The morphological and nanomechanical changes were investigated using atomic force microscopy (AFM) imaging and force mapping below RT using a designed liquid cell with temperature-control. In both systems, the size and shape of SM/Chol-enriched liquid ordered domains (L) and DOPC-enriched liquid disordered phase (L) were monitored at controlled temperatures. AFM based force-mapping showed that rupture forces were consistently higher for L domains than L phases and were decreased for L with decreasing temperature while an increase in breakthrough force was observed in L domains. More interestingly, dynamic changes and defect formations in the hydrated lipid bilayers were mostly detected at low temperature, suggesting a rearrangement of lipid molecules to relieve additional tension introduced upon cooling. Noteworthy, in these model membrane systems, tension-driven defects generally heal on reheating the sample. The results of this work bring new insights to low temperature induced membrane structural reorganization and mechanical stability changes which will bring us one step closer to understand more complex systems such as the MFGM.
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http://dx.doi.org/10.1016/j.bbamem.2017.12.008DOI Listing
March 2018

Transplantation routes affect the efficacy of human umbilical cord mesenchymal stem cells in a rat GDM model.

Clin Chim Acta 2017 Dec 16;475:137-146. Epub 2017 Oct 16.

Department of Obstetrics and Gynecology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, Jiangsu Province, China. Electronic address:

Gestational diabetes mellitus (GDM) is harmful to both the mother and fetus. Although transplantation of human umbilical cord mesenchymal stem cells (HUMSCs) could be a useful therapy for GDM, the influences of different transplantation routes on the therapeutic effects remain unclear. In this study, we isolated and cultured the HUMSCs for transplantation, and the biological activity of HUMSCs was verified by flow cytometric analysis (the positive markers, CD44, CD73, CD105 and CD90, the negative markers, CD45, CD34, CD19, HLA-DR, and CD11b) and potency of osteogenic, adipogenic and chondrogenic differentiation. Streptozotocin (STZ)-induced diabetes mellitus (DM)/GDM rats were transplanted with HUMSCs by different routes: single or multiple tail vein injection, liver parenchyma, and renal capsule transplantation. These were compared to positive controls (STZ-induced, untreated) and negative controls (non-induced, untreated) to determine the effect of the transplant on the control of DM/GDM. The blood glucose level and body weight of rats in each group were determined and showed different effects. Transplantation of HUMSCs to GDM rats can increase the number of offspring in comparison to the negative controls. The weight of the offspring in the transplantation groups also increased due to the therapeutic effect of HUMSCs. Based on results, we concluded that transplanting HUMSCs could effectively alleviate the symptoms of elevated blood glucose and weight loss and improve the body weight and survival rate of offspring. Injections of HUMSCs were required to persistently decrease the blood glucose of DM and GDM rats. Transplanting HUMSCs into the liver or renal capsule of GDM rats led to a similar efficiency of controlling blood glucose and compensation for body weight. HUMSCs therapy increased the number and body weight of offspring and improved their activity. In summary, this study has enabled progress toward determining the optimal route for GDM therapy.
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http://dx.doi.org/10.1016/j.cca.2017.10.013DOI Listing
December 2017

Fabrication of High Content Carbon Nanotube-Polyurethane Sheets with Tailorable Properties.

ACS Appl Mater Interfaces 2017 Sep 31;9(36):30840-30849. Epub 2017 Aug 31.

Security and Disruptive Technologies, National Research Council Canada , Ottawa, Ontario, Canada.

We have fabricated carbon nanotube (CNT)-polyurethane (TPU) sheets via a one-step filtration method that uses a TPU solvent/nonsolvent combination. This solution method allows for control of the composition and processing conditions, significantly reducing both the filtration time and the need for large volumes of solvent to debundle the CNTs. Through an appropriate selection of the solvents and tuning the solvent/nonsolvent ratio, it is possible to enhance the interaction between the CNTs and the polymer chains in solution and improve the CNT exfoliation in the nanocomposites. The composition of the nanocomposites, which defines the characteristics of the material and its mechanical properties, can be precisely controlled. The highest improvements in tensile properties were achieved at a CNT:TPU weight ratio around 35:65 with a Young's modulus of 1270 MPa, stress at 50% strain of 35 MPa, and strength of 41 MPa, corresponding to ∼10-fold improvement in modulus and ∼7-fold improvement in stress at 50% strain, while maintaining a high failure strain. At the same composition, CNTs with higher aspect ratio produce nanocomposites with greater improvements (e.g., strength of 99 MPa). Electrical conductivity also shows a maximum near the same composition, where it can exceed the values achieved for the pristine nanotube buckypaper. The trend in mechanical and electrical properties was understood in terms of the CNT-TPU interfacial interactions and morphological changes occurring in the nanocomposite sheets as a function of increasing the TPU content. The availability of such a simple method and the understanding of the structure-property relationships are expected to be broadly applicable in the nanocomposites field.
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http://dx.doi.org/10.1021/acsami.7b09208DOI Listing
September 2017

Manipulation and Quantification of Graphene Oxide Flake Size: Photoluminescence and Cytotoxicity.

ACS Appl Mater Interfaces 2017 Aug 16;9(34):28911-28921. Epub 2017 Aug 16.

Measurement Science and Standards, National Research Council Canada , 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada.

Single-layered graphene oxide (GO) has exhibited great promise in the areas of sensing, membrane filtration, supercapacitors, bioimaging, and therapeutic carriers because of its biocompatibility, large surface area, and electrochemical, photoluminescent, and optical properties. To elucidate how the physical dimensions of GO affect its intrinsic properties, we employed sonication to produce more than 130 different sizes of GO in aqueous dispersion and implemented new approaches to characterize various GO properties as a function of the average flake size. New protocols were developed to determine and compare the flake size of GO dispersions sonicated with energies up to 20 MJ/g by using dynamic light scattering and atomic force microscopy (AFM). The relationship between the average flake size and sonication energy per unit mass of GO was observed to follow a power law. AFM height measurements showed that the sonication of GO yielded monolayered flakes. Photoluminescence of GO was characterized as a function of the sonication energy (or the average flake size which is the monotonic function of the sonication energy), excitation wavelength, and pH of the dispersion. The strong dependence of the photoluminescence intensity on pH control and the variation of the photoluminescence intensity with different flake sizes were observed. An intense photoluminescence signal, likely related to the separation of the oxidative debris from the GO framework, was found at the highest sonication energies (E ≳ 15 MJ/g) or under extremely alkaline conditions (pH ≳ 11). The cytotoxicity of GO was studied with various flake sizes. Size- and concentration-dependent cytotoxicity was observed for cell lines NIH 3T3 and A549. The NIH 3T3 cell line also demonstrated time-dependent cytotoxicity.
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http://dx.doi.org/10.1021/acsami.7b08585DOI Listing
August 2017

Contribution of Progranulin to Protective Lung Immunity During Bacterial Pneumonia.

J Infect Dis 2017 06;215(11):1764-1773

Department of Laboratory Medicine, The First Affiliated Hospital of Chongqing Medical University.

Background: Progranulin (PGRN) is an important immunomodulatory factor in a variety of inflammatory diseases. However, its role in pulmonary immunity against bacterial infection remains unknown.

Methods: Pneumonia was induced in PGRN-deficient and normal wild-type mice using Pseudomonas aeruginosa or Staphylococcus aureus, and we assessed the effects of PGRN on survival, bacterial burden, cytokine and chemokine production, and pulmonary leukocyte recruitment after bacterial pneumonia.

Results: Patients with community-acquired pneumonia displayed elevated PGRN levels. Likewise, mice with Gram-negative and Gram-positive pneumonia had increased PGRN production in the lung and circulation. Progranulin deficiency led to increased bacterial growth and dissemination accompanied by enhanced lung injury and mortality in bacterial pneumonia, which was associated with impaired recruitment of macrophages and neutrophils in the lung. The reduced number of pulmonary macrophages and neutrophils observed in PGRN-deficient mice was related to a reduction of CCL2 and CXCL1 in the lungs after bacterial pneumonia. Importantly, therapeutic administration of PGRN improved mortality in severe bacterial pneumonia.

Conclusions: This study supports a novel role for PGRN in pulmonary immunity and suggests that treatment with PGRN may be a viable therapy for bacterial pneumonia.
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http://dx.doi.org/10.1093/infdis/jix197DOI Listing
June 2017

Gel-gel phase separation within milk sphingomyelin domains revealed at the nanoscale using atomic force microscopy.

Biochim Biophys Acta Biomembr 2017 May 16;1859(5):949-958. Epub 2017 Feb 16.

STLO, UMR1253, INRA, Agrocampus Ouest, 35000 Rennes, France. Electronic address:

The milk sphingomyelin (MSM) is involved in the formation of ordered lipid domains in the biological milk fat globule membrane (MFGM), where it accounts for about 30%wt of the polar lipids. Moreover, MSM exhibits a large variety in saturated acyl chain lengths (from C16:0 to C24:0-SM) compared to other natural sphingomyelins, which may impact the packing of MSM molecular species in the gel phase domains and the topography of the MFGM. To investigate this, supported lipid bilayers of synthetic sphingomyelins or of MSM-containing mixtures, including a MFGM polar lipid extract, were imaged at temperatures below the Tm of MSM (i.e. <34°C for which MSM is in the gel phase) in hydrated conditions using atomic force microscopy. In all compositions containing MSM, the MSM-rich gel phase domains exhibited lower and upper height levels H, interpreted as two distinct gel phases with ∆H~0.5-1.1nm. Two (lower and upper) gel phases were also found for pure C24:0-SM bilayers or for bilayers of a C16:0-SM/C24:0-SM equimolar mixture, while C16:0-SM bilayers were uniformly flat and less thick than C24:0-SM bilayers. The upper gel phase of MSM-containing bilayers was interpreted as mixed interdigitated C24:0-SM molecules, while the lower gel phase was attributed both to fully interdigitated C24:0-SM molecules and non-interdigitated C16:0-SM molecules. These results show that the composition of natural sphingomyelins, inducing a mismatch between the d18:1 sphingosine and the acyl chains, is important in both the internal organization and the topography of biological membranes, especially that of the MFGM. This organization could be involved in specific biological functions, e.g. the insertion of proteins.
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http://dx.doi.org/10.1016/j.bbamem.2017.02.010DOI Listing
May 2017

The Lnc RNA SPRY4-IT1 Modulates Trophoblast Cell Invasion and Migration by Affecting the Epithelial-Mesenchymal Transition.

Sci Rep 2016 11 17;6:37183. Epub 2016 Nov 17.

Department of Obstetrics and Gynecology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, JiangSu Province, 210029, China.

Preeclampsia is a common, pregnancy-specific disease and a major contributor to maternal and foetal morbidity and mortality. Some placental abnormalities, including deficient implantation, abnormal trophoblast cell function, and improper placental vascular development, are believed to lead to preeclampsia. The long noncoding RNA SPRY4-IT1 is more highly expressed in preeclamptic human placentas than in normal placentas. We assessed the role of epithelial-mesenchymal transition (EMT)-associated invasion and migration in HTR-8/SVneo trophoblast cells. Overexpression of SPRY4-IT1 suppressed trophoblast cell migration and invasion, whereas reduced expression of SPRY4-IT1 prevented the EMT process. Mechanistically, an RNA immunoprecipitation experiment showed that SPRY4-IT1 bound directly to HuR and mediated the β-catenin expression associated with EMT in HTR-8/SVneo cells. Moreover, the expression levels of genes in the WNT family, such as WNT3 and WNT5B, were changed after transfection of HTR-8/SVneo with SPRY4-IT1. Together, our results highlight the roles of SPRY4-IT1 in causing trophoblast cell dysfunction by acting through the Wnt/β-catenin pathway, and consequently in impairing spiral artery remodelling. These results suggest a new potential therapeutic target for intervention against preeclampsia.
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http://dx.doi.org/10.1038/srep37183DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5112580PMC
November 2016

Analysis Method for Quantifying the Morphology of Nanotube Networks.

Langmuir 2016 08 22;32(34):8735-42. Epub 2016 Aug 22.

Measurement Science and Standards, National Research Council Canada , 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada.

While atomic force microscopy (AFM) is a powerful technique for imaging assemblies and networks of nanoscale materials, approaches for quantitative assessment of the morphology of these materials are lacking. Here we present a volume-based approach for analyzing AFM images of assemblies of nano-objects that enables the extraction of relevant parameters describing their morphology. Random networks of single-walled carbon nanotubes (SWCNTs) deposited via solution-phase processing are used as an example to develop the method and demonstrate its utility. AFM imaging shows that the morphology of these networks depends on details of processing and is influenced by choice of substrate, substrate cleaning method, and postdeposition rinsing protocols. A method is outlined to analyze these images and extract relevant parameters describing the network morphology such as the density of SWCNTs and the degree to which tubes are bundled. Because this volume-based approach depends on accurate measurements of the height of individual tubes and their networks, a procedure for obtaining reliable height measurements is also discussed. Obtaining quantitative parameters that describe the network morphology allows going beyond qualitative descriptions of images and will facilitate optimizing network preparation methods based on measurable criteria and correlating performance with morphology.
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http://dx.doi.org/10.1021/acs.langmuir.6b02475DOI Listing
August 2016

Dynamics of vortex quadrupoles in nonrotating trapped Bose-Einstein condensates.

Sci Rep 2016 07 28;6:29066. Epub 2016 Jul 28.

Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.

Dynamics of vortex clusters is essential for understanding diverse superfluid phenomena. In this paper, we examine the dynamics of vortex quadrupoles in a trapped two-dimensional (2D) Bose-Einstein condensate. We find that the movement of these vortex-clusters fall into three distinct regimes which are fully described by the radial positions of the vortices in a 2D isotropic harmonic trap, or by the major radius (minor radius) of the elliptical equipotential lines decided by the vortex positions in a 2D anisotropic harmonic trap. In the "recombination" and "exchange" regimes the quadrupole structure maintains, while the vortices annihilate each other permanently in the "annihilation" regime. We find that the mechanism of the charge flipping in the "exchange" regime and the disappearance of the quadrupole structure in the "annihilation" regime are both through an intermediate state where two vortex dipoles connected through a soliton ring. We give the parameter ranges for these three regimes in coordinate space for a specific initial configuration and phase diagram of the vortex positions with respect to the Thomas-Fermi radius of the condensate. We show that the results are also applicable to systems with quantum fluctuations for the short-time evolution.
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http://dx.doi.org/10.1038/srep29066DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4964626PMC
July 2016

Resveratrol inhibits trophoblast apoptosis through oxidative stress in preeclampsia-model rats.

Molecules 2014 Dec 9;19(12):20570-9. Epub 2014 Dec 9.

Department of Obstetrics and Gynecology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing 210029, Jiangsu, China.

Resveratrol has been shown to be a therapeutic agent for cardiovascular disorders by maintaining a lower redox level in vivo through its anti-oxidant properties. Resveratrol can prevent cells from p53- and reactive oxygen species-dependent apoptosis induced by interleukin-1b. We identified an inhibitory effect of resveratrol against oxidative stress and apoptosis using the TUNEL assay in NG-Nitro-l-arginine methyl ester-induced preeclampsia in rats. To investigate a possible association between resveratrol and the apoptosis caused by oxidative stress in vitro, assays for superoxide dismutase and malondialdehyde as well as flow cytometric analyses were conducted in HTR-8/SVneo cells after hypoxic treatment with or without resveratrol for 24 h. These data suggest that resveratrol significantly opposes the effects of oxidative stress in vivo and in vitro.
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http://dx.doi.org/10.3390/molecules191220570DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6270857PMC
December 2014

Prediction of the reference evapotranspiration using a chaotic approach.

ScientificWorldJournal 2014 16;2014:347625. Epub 2014 Jul 16.

College of Harbor, Coastal and Offshore Engineering, Hohai University, Nanjing 210098, China.

Evapotranspiration is one of the most important hydrological variables in the context of water resources management. An attempt was made to understand and predict the dynamics of reference evapotranspiration from a nonlinear dynamical perspective in this study. The reference evapotranspiration data was calculated using the FAO Penman-Monteith equation with the observed daily meteorological data for the period 1966-2005 at four meteorological stations (i.e., Baotou, Zhangbei, Kaifeng, and Shaoguan) representing a wide range of climatic conditions of China. The correlation dimension method was employed to investigate the chaotic behavior of the reference evapotranspiration series. The existence of chaos in the reference evapotranspiration series at the four different locations was proved by the finite and low correlation dimension. A local approximation approach was employed to forecast the daily reference evapotranspiration series. Low root mean square error (RSME) and mean absolute error (MAE) (for all locations lower than 0.31 and 0.24, resp.), high correlation coefficient (CC), and modified coefficient of efficiency (for all locations larger than 0.97 and 0.8, resp.) indicate that the predicted reference evapotranspiration agrees well with the observed one. The encouraging results indicate the suitableness of chaotic approach for understanding and predicting the dynamics of the reference evapotranspiration.
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http://dx.doi.org/10.1155/2014/347625DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4124658PMC
May 2015
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