Publications by authors named "Guixiang Li"

28 Publications

  • Page 1 of 1

Challenges in tin perovskite solar cells.

Phys Chem Chem Phys 2021 Sep 17. Epub 2021 Sep 17.

Department of Novel Materials and Interfaces for Photovoltaic Solar Cells, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin, Germany.

Perovskite solar cells are the rising star of third-generation photovoltaic technology. With a power conversion efficiency of 25.5%, the record efficiency is close to the theoretical maximum efficiency of a single-junction solar cell. However, lead toxicity threatens commercialization efforts and market accessibility. In this context, Sn-based perovskites are a safe alternative. Nevertheless, the efficiency of Sn-based devices falls far behind the efficiency of Pb-based counterparts. This concise review sheds light on the challenges that the field faces toward making Sn-based perovskites the perovskite photovoltaic benchmark. We identified four key challenges: materials and solvents, film formation, Sn(II) oxidation, and energy band alignment. We illustrate every single challenge and highlight the most successful attempts to overcome them. Finally, we provide our opinion on the most promising trends of this field in the future.
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http://dx.doi.org/10.1039/d1cp02596aDOI Listing
September 2021

Author Correction: The gut microbiome is associated with brain structure and function in schizophrenia.

Sci Rep 2021 Aug 30;11(1):17643. Epub 2021 Aug 30.

Department of Biomedical Engineering, School of Material Science and Engineering, South China University of Technology, Guangzhou, 510006, China.

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http://dx.doi.org/10.1038/s41598-021-96985-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8405604PMC
August 2021

Effects of Brain Atlases and Machine Learning Methods on the Discrimination of Schizophrenia Patients: A Multimodal MRI Study.

Front Neurosci 2021 27;15:697168. Epub 2021 Jul 27.

Department of Biomedical Engineering, School of Material Science and Engineering, South China University of Technology, Guangzhou, China.

Recently, machine learning techniques have been widely applied in discriminative studies of schizophrenia (SZ) patients with multimodal magnetic resonance imaging (MRI); however, the effects of brain atlases and machine learning methods remain largely unknown. In this study, we collected MRI data for 61 first-episode SZ patients (FESZ), 79 chronic SZ patients (CSZ) and 205 normal controls (NC) and calculated 4 MRI measurements, including regional gray matter volume (GMV), regional homogeneity (ReHo), amplitude of low-frequency fluctuation and degree centrality. We systematically analyzed the performance of two classifications (SZ vs NC; FESZ vs CSZ) based on the combinations of three brain atlases, five classifiers, two cross validation methods and 3 dimensionality reduction algorithms. Our results showed that the groupwise whole-brain atlas with 268 ROIs outperformed the other two brain atlases. In addition, the leave-one-out cross validation was the best cross validation method to select the best hyperparameter set, but the classification performances by different classifiers and dimensionality reduction algorithms were quite similar. Importantly, the contributions of input features to both classifications were higher with the GMV and ReHo features of brain regions in the prefrontal and temporal gyri. Furthermore, an ensemble learning method was performed to establish an integrated model, in which classification performance was improved. Taken together, these findings indicated the effects of these factors in constructing effective classifiers for psychiatric diseases and showed that the integrated model has the potential to improve the clinical diagnosis and treatment evaluation of SZ.
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http://dx.doi.org/10.3389/fnins.2021.697168DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8353157PMC
July 2021

A particle swarm optimization improved BP neural network intelligent model for electrocardiogram classification.

BMC Med Inform Decis Mak 2021 07 30;21(Suppl 2):99. Epub 2021 Jul 30.

Department of Biomedical Engineering, School of Material Science and Engineering, South China University of Technology, Guangzhou, 510006, China.

Background: As proven to reflect the work state of heart and physiological situation objectively, electrocardiogram (ECG) is widely used in the assessment of human health, especially the diagnosis of heart disease. The accuracy and reliability of abnormal ECG (AECG) decision depend to a large extent on the feature extraction. However, it is often uneasy or even impossible to obtain accurate features, as the detection process of ECG is easily disturbed by the external environment. And AECG got many species and great variation. What's more, the ECG result obtained after a long time past, which can not reach the purpose of early warning or real-time disease diagnosis. Therefore, developing an intelligent classification model with an accurate feature extraction method to identify AECG is of quite significance. This study aimed to explore an accurate feature extraction method of ECG and establish a suitable model for identifying AECG and the diagnosis of heart disease.

Methods: In this research, the wavelet combined with four operations and adaptive threshold methods were applied to filter the ECG and extract its feature waves first. Then, a BP neural network (BPNN) intelligent model and a particle swarm optimization (PSO) improved BPNN (PSO-BPNN) intelligent model based on MIT-BIH open database was established to identify ECG. To reduce the complexity of the model, the principal component analysis (PCA) was used to minimize the feature dimension.

Results: Wavelet transforms combined four operations and adaptive threshold methods were capable of ECG filtering and feature extraction. PCA can significantly deduce the modeling feature dimension to minimize the complexity and save classification time. The PSO-BPNN intelligent model was suitable for identifying five types of ECG and showed better effects while comparing it with the BPNN model.

Conclusion: In summary, it was further concluded that the PSO-BPNN intelligent model would be a suitable way to identify AECG and provide a tool for the diagnosis of heart disease.
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http://dx.doi.org/10.1186/s12911-021-01453-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8322832PMC
July 2021

Fluoride Chemistry in Tin Halide Perovskites.

Angew Chem Int Ed Engl 2021 Sep 24;60(39):21583-21591. Epub 2021 Jul 24.

Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109, Berlin, Germany.

Tin is the frontrunner for substituting toxic lead in perovskite solar cells. However, tin suffers the detrimental oxidation of Sn to Sn . Most of reported strategies employ SnF in the perovskite precursor solution to prevent Sn formation. Nevertheless, the working mechanism of this additive remains debated. To further elucidate it, we investigate the fluoride chemistry in tin halide perovskites by complementary analytical tools. NMR analysis of the precursor solution discloses a strong preferential affinity of fluoride anions for Sn over Sn , selectively complexing it as SnF . Hard X-ray photoelectron spectroscopy on films shows the lower tendency of SnF than SnI to get included in the perovskite structure, hence preventing the inclusion of Sn in the film. Finally, small-angle X-ray scattering reveals the strong influence of fluoride on the colloidal chemistry of precursor dispersions, directly affecting perovskite crystallization.
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http://dx.doi.org/10.1002/anie.202107599DOI Listing
September 2021

The gut microbiome is associated with brain structure and function in schizophrenia.

Sci Rep 2021 05 7;11(1):9743. Epub 2021 May 7.

Department of Biomedical Engineering, School of Material Science and Engineering, South China University of Technology, Guangzhou, 510006, China.

The effect of the gut microbiome on the central nervous system and its possible role in mental disorders have received increasing attention. However, knowledge about the relationship between the gut microbiome and brain structure and function is still very limited. Here, we used 16S rRNA sequencing with structural magnetic resonance imaging (sMRI) and resting-state functional (rs-fMRI) to investigate differences in fecal microbiota between 38 patients with schizophrenia (SZ) and 38 demographically matched normal controls (NCs) and explored whether such differences were associated with brain structure and function. At the genus level, we found that the relative abundance of Ruminococcus and Roseburia was significantly lower, whereas the abundance of Veillonella was significantly higher in SZ patients than in NCs. Additionally, the analysis of MRI data revealed that several brain regions showed significantly lower gray matter volume (GMV) and regional homogeneity (ReHo) but significantly higher amplitude of low-frequency fluctuation in SZ patients than in NCs. Moreover, the alpha diversity of the gut microbiota showed a strong linear relationship with the values of both GMV and ReHo. In SZ patients, the ReHo indexes in the right STC (r = - 0.35, p = 0.031, FDR corrected p = 0.039), the left cuneus (r = - 0.33, p = 0.044, FDR corrected p = 0.053) and the right MTC (r = - 0.34, p = 0.03, FDR corrected p = 0.052) were negatively correlated with the abundance of the genus Roseburia. Our results suggest that the potential role of the gut microbiome in SZ is related to alterations in brain structure and function. This study provides insights into the underlying neuropathology of SZ.
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http://dx.doi.org/10.1038/s41598-021-89166-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8105323PMC
May 2021

Can nutrient uptake by Carex counteract eutrophication in fen peatlands?

Sci Total Environ 2021 Sep 23;785:147276. Epub 2021 Apr 23.

Experimental Plant Ecology, Institute of Botany and Landscape Ecology, University of Greifswald, partner in the Greifswald Mire Centre, Germany. Electronic address:

Ground- and surface-water-fed peatlands (i.e., fens) of temperate Europe face high anthropogenic nutrient loads from atmospheric deposition, agricultural catchment areas, and from peat decomposition, if drained. As a result, nitrogen loads may exceed a fen's natural nutrient removal capacity, leading to increased eutrophication of adjacent water bodies. Therefore, it is important to address possible means to decrease a fen's nutrient load, including nutrient uptake by fen plants. To assess how much fen plants can contribute to nutrient removal by uptake, nutrient stocks of above- and below-ground biomass need to be quantified. Therefore, we investigated nitrogen, phosphorous, and potassium uptake capacities of sedges (Carex species), which are common dominants in fen plant communities. We grew specimens of five Carex species with varying preferences in nutrient availability under controlled, different nutrient levels. We show that Carex above-ground biomass harvest can remove up to one third of a system's total nitrogen even at high loads of about 40 g nitrogen m. Species-specific differences in biomass production, rather than preferences in nutrient availability under natural conditions, were drivers of standing nutrient stocks: Highly productive species, i.e., C. acutiformis and C. rostrata, had highest nutrient standing stocks across all nutrient levels. Amounts of nutrients stored in shoots increased almost linearly with increasing nutrient levels, whereas below-ground nutrient stocks species-specifically increased, saturated, or decreased, with increasing nutrient levels. As a rough estimate, depending on the species, 6-16 cycles of annual above-ground harvest would suffice to decrease nitrogen concentrations from the highest to the lowest level used in this study. Overall, our results indicate that Carex biomass harvest can be an efficient means to counteract anthropogenic nitrogen eutrophication in fens.
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http://dx.doi.org/10.1016/j.scitotenv.2021.147276DOI Listing
September 2021

Altered Heart Rate Variability in Patients With Schizophrenia During an Autonomic Nervous Test.

Front Psychiatry 2021 30;12:626991. Epub 2021 Mar 30.

Department of Biomedical Engineering, School of Material Science and Engineering, South China University of Technology, Guangzhou, China.

Reduced heart rate variability (HRV) and dysfunction of the autonomic nervous system (ANS) have been observed in schizophrenia patients. HRV parameters of schizophrenia patients in the resting state have been well-documented; however, these parameters of schizophrenia patients who experience continuous psychophysiological stress remain unclear. The objective of this study was to systematically explore the linear and nonlinear HRV parameters between schizophrenia patients and normal controls and to detect the adaptive capabilities of HRV of schizophrenia patients during the stimulation tests of autonomic nervous system. Forty-five schizophrenia patients and forty-five normal controls, matched for age, sex and body mass index, completed a 14 min ANS test. Thirteen linear and nonlinear HRV parameters of all subjects under the ANS test were computed and statistically analyzed between groups and between sessions. The STROBE checklist was adhered to in this study. All time-domain HRV features in the ANS test were significantly different between schizophrenia patients and normal controls ( < 0.01). The schizophrenia patients showed significantly low values in the Poincaré indices, which revealed significantly decreased heart rate fluctuation complexity compared with that of normal controls ( < 0.001). In addition, the normal controls, not schizophrenia patients, showed significant differences between the recovery and stress states in the parameters of low frequency, high frequency, and nonlinear dynamics. Schizophrenia patients showed autonomic dysfunction of the heart in a series of stimulation tests of the autonomic nervous system and could not regain normal physiological functions after stress cessation. Our findings revealed that the dynamic parameters of HRV in psychophysiological stress are sensitive and practical for a diagnosis of schizophrenia.
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http://dx.doi.org/10.3389/fpsyt.2021.626991DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8074969PMC
March 2021

Activity and Resistance-Related Point Mutations in Target Protein PcORP1 of Fluoxapiprolin in .

J Agric Food Chem 2021 Apr 25;69(13):3827-3835. Epub 2021 Mar 25.

State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, 3 Taicheng Road, Yangling 712100, Shaanxi, People's Republic of China.

Fluoxapiprolin is a new piperidinyl thiazole isoxazoline fungicide developed by Bayer Crop Science in 2012, but the sensitivity and resistance mechanism of fluoxapiprolin are unclear. In this study, the sensitivities of 130 isolates to fluoxapiprolin were determined, and a unimodal distribution was observed with a mean EC value of 0.00043 μg/mL. Nine stable fluoxapiprolin-resistant mutants were obtained by fungicide adaption. The fitness of mutants was similar to or lower than that of the corresponding parental isolate. Seven heterozygous point mutations in the target protein PcORP1 were found in these mutants. These point mutations were confirmed in PsORP1 of homologue positions using the CRISPR/Cas9 system. G770V and N835S+I877F do confer high fluoxapiprolin resistance (resistance factor, RF > 1000), and ΔN835, N767I, and N837T+S910C lead to low resistance (RF < 100). transformants containing L733W, S768F, S768Y, Δ818/F819, N837Y, N837F, P861H, L863W, and I877Y in PsORP1 were also associated with high fluoxapiprolin resistance (RF > 100). In conclusion, the resistance risk of to fluoxapiprolin is moderate, and multiple point mutations in PcORP1 could confer different resistance levels to fluoxapiprolin.
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http://dx.doi.org/10.1021/acs.jafc.0c05119DOI Listing
April 2021

Difenoconazole Resistance Shift in From Tomato in China Associated With Inducible Expression of .

Plant Dis 2021 Feb 16;105(2):400-407. Epub 2020 Dec 16.

Department of Plant Pathology, China Agricultural University, Beijing 100193, China.

Gray mold caused by is one of the most important diseases in tomato. It can be controlled effectively by demethylation inhibitor (DMI) fungicides, but their resistance status after long-term use in the field is unclear. The baseline sensitivity to difenoconazole of 142 isolates from China with no history of DMI usage was characterized, with a mean effective concentration for 50% mycelial growth inhibition (EC) of 0.97 ± 0.50 μg/ml. EC values for difenoconazole sensitivity of another 248 isolates collected in 2011 and 2016 ranged from 0.04 to 11.99 μg/ml, and the frequency of difenoconazole sensitivity formed a nonnormal distribution curve. Detached fruit studies revealed that isolates with EC values of approximately 6.00 μg/ml were not controlled effectively. The mean EC of the resistant isolates changed from 6.74 to 8.65 μg/ml between 2011 and 2016. Positive cross-resistance was only observed between difenoconazole and two DMIs. One dual resistant isolate and one triple resistant isolate were found among the difenoconazole-resistant isolates collected in 2016, associated with point mutations in corresponding target proteins of the fungicides azoxystrobin and fludioxonil. This indicated that not only showed higher difenoconazole resistance levels but gradually changed from single to multiple fungicide resistance over time. No amino acid variation was found in the CYP51 protein. In the absence of difenoconazole, the relative expression of was not significantly different in sensitive and resistant isolates. Induced expression of is an important determinant of DMI resistance in from tomato. However, nucleotide variants found in the upstream region had no association with the fungicide resistance phenotype. These results will be helpful for the management of in the field.
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http://dx.doi.org/10.1094/PDIS-03-20-0508-REDOI Listing
February 2021

Phosphorus-Doped Iron Nitride Nanoparticles Encapsulated by Nitrogen-Doped Carbon Nanosheets on Iron Foam In Situ Derived from Saccharomycetes Cerevisiae for Electrocatalytic Overall Water Splitting.

Small 2020 08 2;16(32):e2001980. Epub 2020 Jul 2.

Collaborative Innovation Center of Technology and Equipment for Biological Diagnosis and Therapy in Universities of Shandong, Institute for Advanced Interdisciplinary Research (iAIR), University of Jinan, Jinan, 250022, P. R. China.

It is vitally essential to propose a novel, economical, and safe preparation method to design highly efficient electrocatalysts. Herein, phosphorus-doped iron nitride nanoparticles encapsulated by nitrogen-doped carbon nanosheets are grown directly on the iron foam substrate (P-Fe [email protected] NSs/IF) by in situ deriving from Saccharomycetes cerevisiae (S. cerevisiae), where anion elements of C, N, and P all from S. cerevisiae replace the hazardous CH , NH , and H P. The diffusion pattern of N, P in S. cerevisiae and contact form between metal and S. cerevisiae observably affect the composition and phase of the product during high-temperature calcination. The obtained P-Fe [email protected] NSs/IF demonstrates superior electrocatalytic performance for the hydrogen evolution reaction and oxygen evolution reaction, also satisfying durability. Theoretical calculation confirms that Fe sites of P-Fe N serve as the active center, and N sites and P doping regulate the hydrogen binding strength to enhance catalytic ability. Additionally, the two-electrode electrolyzer assembled by P-Fe [email protected] NSs/IF as both anode and cathode electrodes needs only 1.61 V to reach 10 mA cm for overall water splitting with a superb stability. The S. cerevisiae-based process presents a feasible approach for synthesis of nitrides, carbides, phosphides, and electrocatalytic applications.
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http://dx.doi.org/10.1002/smll.202001980DOI Listing
August 2020

Sensitivity of Pythium spp. and Phytopythium spp. and tolerance mechanism of Pythium spp. to oxathiapiprolin.

Pest Manag Sci 2020 Dec 6;76(12):3975-3981. Epub 2020 Jul 6.

State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, China.

Background: Oxathiapiprolin, developed by DuPont, is the only commercial oxysterol-binding protein inhibitor (OSBPI) of oomycete pathogens. Although the activity of oxathiapiprolin on some Pythium spp. and Phytopythium spp. has been reported, it has not been tested on many other species, and little is known about the mechanisms of Pythium spp. that are tolerant to it.

Results: Oxathiapiprolin exhibited a strong inhibitory effect on mycelial growth of Phy. litorale, Phy. helicoides and Phy. chamaehyphon, with EC values ranging from 0.002 to 0.013 μg mL . It also showed good effectiveness against Py. splendens and two Py. ultimum isolates, with EC values ranging from 0.167 to 0.706 μg mL , but showed no activity against 14 other Pythium spp. Oxathiapiprolin provoked a slight upregulation of PuORP1 in Py. ultimum, but it did not lead to PaORP1-1 or PaORP1-2 overexpression in Py. aphanidermatum. Transformation and expression of PuORP1, PaORP1-1 or PaORP1-2 in the sensitive wild-type Phytophthora sojae isolate P6497 confirmed that either the PuORP1, PaORP1-1 or PaORP1-2 was responsible for the observed oxathiapiprolin tolerance.

Conclusion: This study showed that oxathiapiprolin had excellent activity against Phytopythium spp. but displayed a differentiated activity against different Pythium spp. ORP1s in Pythium spp. are positively related to the tolerance of Pythium species to oxathiapiprolin. © 2020 Society of Chemical Industry.
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http://dx.doi.org/10.1002/ps.5946DOI Listing
December 2020

Preparation of montmorillonite modified biochar with various temperatures and their mechanism for Zn ion removal.

J Hazard Mater 2020 06 15;391:121692. Epub 2019 Nov 15.

School of Water Conservancy and Civil Engineering, Northeast Agricultural University, Harbin 150030, China; Joint Laboratory of Northeast Agricultural University and Max Planck Institute of Colloids and Interfaces (NEAU-MPICI), Harbin 150030, China. Electronic address:

Because of its layered structure, excellent adsorption, catalytic and ion exchange properties, strong passivation, and superior adsorption capacity for heavy metals, montmorillonite as biochar modifier was introduced. Montmorillonite modified biochar composites (BC-MNT) were successfully prepared by one-step hydrothermal progress and subsequent pyrolysis for the application of Zn (II) removal from aqueous solution. Herein, our research mainly explored the effect of different hydrothermal method/pyrolysis temperatures on the adsorption properties of montmorillonite-biochar composites, since that temperature can greatly change the surface functional groups and chemical composition and structure of biochar. Primarily, adopting VK analysis method analyzed raw biochar and montmorillonite modified biochar at different temperature condition. For further research, adsorption mechanism was realized by means of SEM-EDS, XRD, FTIR, and XPS, as concluded that electrostatic interaction between the negative charge of the interlayers and Zn (II) and surface complexation took up a dominant role. The kinetic and isothermal adsorption mathematical model fitting were also performed, which was more suitable for pseudo-second order and Freundlich model, suggesting that the limited speed stage was dominated by chemical forces. The optimal preparation temperature (350 °C) and maximum adsorption amount (8.163 mg·g) were determined by the adsorption experiment model.
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http://dx.doi.org/10.1016/j.jhazmat.2019.121692DOI Listing
June 2020

Multiple point mutations in PsORP1 gene conferring different resistance levels to oxathiapiprolin confirmed using CRISPR-Cas9 in Phytophthora sojae.

Pest Manag Sci 2020 Jul 24;76(7):2434-2440. Epub 2020 Feb 24.

State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, China.

Background: Oxathiapiprolin is among the first commercial oxysterol-binding protein inhibitors (OSBPIs) developed by DuPont Corporation and shows excellent activity against plant-pathogenic oomycetes. Although more than 21 target site mutations have been identified in insensitive oomycetes, only G770V, G839W, and ΔN837 have been verified to confer oxathiapiprolin resistance in Phytophthora capsici or P. sojae. The effect of other mutations on OSBPIs sensitivity requires urgent investigation.

Results: P. sojae transformants containing 16 mutations of PsORP1 were recovered using the CRISPR-Cas9 system. Transformants containing L733W, S768F, S768Y, N837Y, N837F, P861H, L863W, or I877Y showed high oxathiapiprolin resistance, with resistant factors (RFs) > 3000. Point mutations S768K, S768I, G770L, G770P, G770A, ΔG818/F819, N837I, and I877F exhibited low resistance, with RFs < 80. Phenotype assays revealed that the most highly resistant transformants showed enhanced or similar pathogenicity, oospore production, and cyst gemination. However, most transformants displayed decreased sporangia and zoospore production compared with parental wild-type P6497.

Conclusion: This study demonstrated that L733W, S768F, S768Y, N837Y, N837F, P861H, L863W, and I877Y in PsORP1 confer high oxathiapiprolin resistance in P. sojae.
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http://dx.doi.org/10.1002/ps.5784DOI Listing
July 2020

Synthetic Humic Acids Solubilize Otherwise Insoluble Phosphates to Improve Soil Fertility.

Angew Chem Int Ed Engl 2019 12 4;58(52):18813-18816. Epub 2019 Dec 4.

Max Planck Institute of Colloids and Interfaces Department of Colloid Chemistry, 14476, Potsdam, Germany.

Artificial humic acids (A-HA) made from biomass in a hydrothermal process turn otherwise highly insoluble phosphates (e.g. iron phosphate as a model) into highly available phosphorus, which contributes to the fertility of soils and the coupled plant growth. A detailed electron microscopy study revealed etching of the primary iron phosphate crystals by the -COOH and phenolic groups of humic acids, but also illustrated the importance of the redox properties of humic matter on the nanoscale. The combined effects result in the formation of then bioavailable phosphate nanoparticles stabilized by humic matter. Typical agricultural chemical tests indicate that the content of total P and directly plant-available P improved largely. Comparative pot planting experiments before and after treatment of phosphates with A-HA demonstrate significantly enhanced plant growth, as quantified in higher aboveground and belowground plant biomass.
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http://dx.doi.org/10.1002/anie.201911060DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6973123PMC
December 2019

Electrochemical Flocculation Integrated Hydrogen Evolution Reaction of [email protected] Carbon Nanotubes on Iron Foam for Ultralow Voltage Electrolysis in Neutral Media.

Adv Sci (Weinh) 2019 Sep 22;6(18):1901458. Epub 2019 Jul 22.

The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters Ministry of Education Guangzhou Key Laboratory for Surface Chemistry of Energy Materials School of Environment and Energy South China University of Technology Guangzhou Higher Education Mega Centre Guangzhou 510006 P. R. China.

Hydrogen (H) production is a key step in solving the energy crisis in the future. Electrocatalytic water splitting suffers from sluggish anodic oxygen evolution reaction (OER) kinetics leading to low energy conversion efficiency. Herein, a strategy is presented that integrates anodic electrochemical flocculation with cathodic hydrogen production from water splitting in 0.5 m NaSO. Iron encapsulated in a nitrogen-doped carbon nanotubes array on iron foam ([email protected]/IF) is employed as an electrode for the hydrogen evolution reaction (HER), and the [email protected]/IF possesses superior HER activity requiring an overpotential of 525 mV to achieve 10 mA cm, which is close to that of 20 wt% Pt/C. Benefiting from the lower oxidation potential of iron (°, 0.44 V) than that of OER ( , 1.23 V), the cell voltage for integrated electrochemical flocculation and H production is significantly reduced by 1.31 V relative to overall water splitting to achieve 20 mA cm. More important, the production of electrochemical flocculation can be applied to water purification, because of the excellent adsorption capacity. Finally, metal-carbon electrocatalysts are prepared again by pyrolysis of flocculation adsorbents containing toxic heavy metals and organics. This result provides a new direction for designing a heterogeneous electrolysis system for energy conversion and environmental treatment applications.
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http://dx.doi.org/10.1002/advs.201901458DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6755524PMC
September 2019

N-Doped MoC Nanobelts/Graphene Nanosheets Bonded with Hydroxy Nanocellulose as Flexible and Editable Electrode for Hydrogen Evolution Reaction.

iScience 2019 Sep 3;19:1090-1100. Epub 2019 Sep 3.

Collaborative Innovation Center of Technology and Equipment for Biological Diagnosis and Therapy in Universities of Shandong, Institute for Advanced Interdisciplinary Research (iAIR), University of Jinan, Jinan 250022, P. R. China; Guangzhou Key Laboratory for Surface Chemistry of Energy Materials, School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou 510006, P. R. China. Electronic address:

The large-scale application of economically efficient electrocatalysts for hydrogen evolution reaction (HER) is limited in view of the high cost of polymer binders (Nafion) for immobilizing of powder catalysts. In this work, nitrogen-doped molybdenum carbide nanobelts (N-MoC NBs) with porous structure are synthesized through a direct pyrolysis process using the pre-prepared molybdenum oxide nanobelts (MoO NBs). Nanocellulose instead of Nafion-bonded N-MoC NBs ([email protected]) exhibits superior performance toward HER, because of excellent dispersibility and multiple exposed catalytically active sites. Furthermore, the conductive film composed of N-MoC NBs, graphene nanosheets, and nanocellulose (N-MoC/[email protected]) is fabricated by simple vacuum filtration, as flexible and editable electrode, which possesses excellent performance for scale HER applications. This work not only proposes the potential of nanocellulose to replace Nafion for binding powder catalysts, but also offers a facile strategy to prepare flexible and conductive films for a wide variety of nanomaterials.
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http://dx.doi.org/10.1016/j.isci.2019.08.055DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6807260PMC
September 2019

High-dispersion zero-valent iron particles stabilized by artificial humic acid for lead ion removal.

J Hazard Mater 2020 02 5;383:121170. Epub 2019 Sep 5.

School of Water Conservancy and Civil Engineering, Northeast Agricultural University, Harbin 150030, China. Electronic address:

Nano zero-valent iron (nZVI), as a high-efficiency adsorbent for heavy metals, often suffers being oxidized and assembling together due to small size and super reactivity, further decreasing its adsorption performance and limiting application ranges. Herein, we have designed a novel adsorbent with high-dispersion nZVI stabilized by as-prepared artificial humic acid (AHA-nZVI) derived from hydrothermal humification (HTH) technology. Introduction of artificial humic acid (A-HA) can effectively reduce the oxidation and agglomeration of nZVI, leading to superior kinetic removal efficiency of Pb (> 99.2%) and huge Langmuir removal capacity of 649.0 mg/g. The combination of nZVI and A-HA (contained abundant functional groups, i.e. -OH and -COOH) via C-O-Fe bonding makes nZVI have good dispersion and oxidation resistance. Multiple interaction mechanisms including reduction reaction, complexation and co-precipitation between heavy metals and AHA-nZVI samples are realized. Overall, AHA-nZVI is a promising material for high-performance heavy metal contaminated water treatment.
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http://dx.doi.org/10.1016/j.jhazmat.2019.121170DOI Listing
February 2020

Genome-wide analysis of the NF-Y gene family in peach (Prunus persica L.).

BMC Genomics 2019 Jul 26;20(1):612. Epub 2019 Jul 26.

Shandong Institute of Pomology, Taian, Shandong, China.

Background: Nuclear Factor Y (NF-Y) is a heterotrimeric complex composed of three unique subunits: NF-YA, NF-YB, and NF-YC. The NF-Y transcription factor complex binds to the CCAAT box of eukaryotic promoters, playing a vital role in various biological processes in plants. However, the NF-Y gene family has not yet been reported from the peach genome. The current study identified and classified candidate peach NF-Y genes for further functional analysis of this family.

Results: The current study identified 24 Nuclear Factor Y (NF-Y) transcription factor subunits (6 NF-YA, 12 NF-YB, and 6 NF-YC subunits) in peach. These NF-Y subunits were described with respect to basic physicochemical characteristics, chromosome locations, gene structures, and conserved domains. Based on an analysis of the phylogenetic relationships among peach NF-Ys, six pairs of paralogous NF-Ys were detected. The expansion of the peach NF-Y family occurred by segmental and tandem duplication. Phylogenetic gene synteny of NF-Y proteins was observed between peach and Arabidopsis, and five pairs of paralogous NF-Y proteins from peach and Arabidopsis were identified. Twenty-four peach NF-Ys displayed a diversity of tissue expression patterns. In addition, drought-responsive cis-elements were observed in peach NF-Y promoters, and 9 peach NF-Y genes were shown to distinctly increase their transcript abundances under drought stress.

Conclusions: This study identified 24 NF-Y genes in the peach genome and analysed their properties at different levels, providing a foundation for researchers to understand this gene family in peach. The up-regulation of 9 NF-Y genes under drought stress indicates that they can serve as candidate functional genes to further study drought resistance in peach.
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http://dx.doi.org/10.1186/s12864-019-5968-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6660701PMC
July 2019

Ferrofluid-based liquid-phase microextraction: Analysis of four phenolic compounds in milks and fruit juices.

Food Chem 2018 Sep 13;261:96-102. Epub 2018 Apr 13.

Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Yunnan Province 650500, China. Electronic address:

A novel liquid-phase microextraction based on the ferrofluid was successfully applied for the extraction and determination of four phenolic compounds (bisphenol-A, bisphenol-AF, tetrabromobisphenol-A and 4-tert-octylphenol) in milks and fruit juices. In this study, a range of alkyl (C-C) alcohols as the carrier liquid were used for the preparation of ferrofluids. The study showed that an appropriate chain length of alkyl alcohol may improve the extraction efficiency and maintain the integrity of ferrofluids during extraction, so 1-heptanol (C) was selected as the optimal carrier liquid. Specifically, the effects of various parameters on the extraction of phenolic compounds were investigated and optimized. Under the optimized conditions, the limits of detection were between 0.35 and 0.66 μg L. The intra-day and inter-day precision (RSD %) for the analytes at 10 and 50 μg L were in the range of 3.2-6.7 % and 2.9-7.1%, respectively.
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http://dx.doi.org/10.1016/j.foodchem.2018.04.038DOI Listing
September 2018

TiO nanodots anchored on nitrogen-doped carbon nanotubes encapsulated cobalt nanoparticles as photocatalysts with photo-enhanced catalytic activity towards the pollutant removal.

J Colloid Interface Sci 2018 Sep 27;526:158-166. Epub 2018 Apr 27.

School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, PR China. Electronic address:

Constructing hierarchical structure is an effective approach to improve the activities of catalysts. Herein, a novel hierarchical structure of TiO nanodots anchored on N-doped carbon nanotubes encapsulated Co nanoparticles (TiO/[email protected]) was synthesized by a simple pyrolysis method. Their catalytic performances were examined in the oxidative and light-assisted degradation of recalcitrant pollutants in the presence of the peroxymonosulfate (PMS). The Orange II removal efficiency within 15 min reached about 98.48% in TiO/[email protected]/PMS system. In this system, Co is used to react with PMS to generate free radicals for the degradation of dyes. The carbon shell benefits the adsorption of dyes and prevents the catalysts from dissolving in the solution. Besides, under light irradiation, TiO nanodots can be excited to generate photo-induced electrons, which can reduce inner Co to Co in the degradation process, thus TiO/[email protected] exhabited high activity and outstanding stability in degradation process. The as-prepared TiO/[email protected] catalyst showed efficient degradation and superior stability, which would make it a great promise in practical applications for sewage treatment.
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http://dx.doi.org/10.1016/j.jcis.2018.04.102DOI Listing
September 2018

Bottom-up synthesis of ultra-small molybdenum disulfide-polyvinylpyrrolidone nanosheets for imaging-guided tumor regression.

Oncotarget 2017 Dec 8;8(63):106707-106720. Epub 2017 Nov 8.

Department of Gastroenterology, Changhai Hospital, Second Military Medical University, Shanghai 200433, China.

The two-dimensional molybdenum disulfide (MoS) nanosheet has been extensively studied as a novel photothermal transducing agent. However, top-down exfoliation to produce MoS nanosheets is inefficient, and MoS nanosheet surface modification procedures are complex. Here, we report the synchronous synthesis and surface modification of 2D MoS nanosheets with a polyvinylpyrrolidone (PVP)-assisted one-pot hydrothermal method. Due to the chelating-coordinating effect between the lone-pair electrons of the PVP carbonyl oxygen and the unoccupied 4d orbitals of molybdenum, the PVP chains could graft onto the surface of MoS and guide the growth of the nanosheets. The resultant MoS-PVP nanosheets were ultra-small (21.4 ± 4.4 nm) and exhibited excellent colloidal stability. Moreover, the strong near-infrared absorption of the MoS-PVP nanosheets enabled sensitive photothermal conversion performance (with a mass extinction coefficient of 23.33 L g cm) and / photoacoustic imaging. The MoS-PVP nanosheets had excellent and compatibility and were used for highly efficient tumor photothermal therapy in xenograft tumor-bearing mice. The findings in this report will facilitate the rational design of stable colloidal 2D transition-metal dichalcogenides for effective photothermal cancer therapy.
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http://dx.doi.org/10.18632/oncotarget.22477DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5739768PMC
December 2017

Bottom-up synthesis of WS nanosheets with synchronous surface modification for imaging guided tumor regression.

Acta Biomater 2017 08 10;58:442-454. Epub 2017 Jun 10.

College of Science, University of Shanghai for Science and Technology, No. 334 Jungong Road, Shanghai 200093, China. Electronic address:

Two-dimensional transition metal dichalcogenides (TMDs) have been receiving great attention as NIR photothermal transducing agent in tumor photothermal therapy. Keeping in mind the low efficiency of the conventional top-down exfoliated 2D TMDs and the complexity of their surface modifications, we herein proposed a bottom-up strategy for the one-pot hydrothermal and controlled synthesis of surface polyvinyl pyrrolidone (PVP) modified WS nanosheets. The material design was based on the chelating-coordinating effect between the lone pair electrons of oxygen of PVP carbonyl group and the unoccupied orbital (5d orbitals) of tungsten. The WS nanosheets with synchronous surface PVP grafting showed an excellent photothermal conversion performance, while the surface anchored PVP guaranteed its colloidal stability. Moreover, the strong X-ray attenuation ability and near-infrared (NIR) absorbance of WS-PVP enabled the sensitive in vitro and in vivo computed tomography and photoacoustic imaging. The WS-PVP nanosheets were biocompatible and exhibited promising in vitro and in vivo anti-cancer efficacy. Findings in this report may greatly promote the design of colloidal stable and biocompatible 2D TMDs and their future clinical translations.

Statement Of Significance: A bottom-up strategy for the one-pot and controlled synthesis of surface polyvinyl pyrrolidone (PVP) modified WS nanosheets was proposed for the first time. By hydrothermally treating the mixture solution of tetrathiotungstate and PVP, Owing to the chelating-coordinating effect between the lone pair electrons of oxygen of PVP carbonyl group and the unoccupied orbital (5d orbitals) of tungsten, PVP was synchronously graphed on WS-PVP nanosheets surface. The formed WS-PVP nanosheets were colloidal stable, biocompatible, and exhibited promising computed tomography, photoacoustic imaging and tumor photothermal therapy efficacy both in vitro and in vivo.
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http://dx.doi.org/10.1016/j.actbio.2017.06.014DOI Listing
August 2017

Regulated Synthesis of Mo Sheets and Their Derivative MoX Sheets (X: P, S, or C) as Efficient Electrocatalysts for Hydrogen Evolution Reactions.

ACS Appl Mater Interfaces 2017 Mar 23;9(9):8041-8046. Epub 2017 Feb 23.

New Energy Research Institute, School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Center , Guangzhou, Guangdong 510006, China.

Electrochemical H generation from HO has been focused on the exploration of non-noble metals as well as earth-rich catalysts. In our practical work, we provide a simple cost-efficient fabrication process to prepare large Mo sheets via the controlled equilibrium between sublimation of MoO and reduction of H. Porous MoP sheets were synthesized from the obtained Mo sheets as the Mo source and template which exhibit notable activity in the hydrogen evolution reaction with a low onset potential of -88 mV vs RHE, small Tafel value of 54.5 mV/dec, and strong catalytic stability. With Mo sheets as the universal Mo source and template, MoS and MoC sheets were synthesized by a similar process, and the corresponding catalytic activities were calculated by density functional theory.
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http://dx.doi.org/10.1021/acsami.6b12103DOI Listing
March 2017

Contrasting elevational diversity patterns for soil bacteria between two ecosystems divided by the treeline.

Sci China Life Sci 2016 Nov 5;59(11):1177-1186. Epub 2016 Sep 5.

State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.

Above- and below-ground organisms are closely linked, but how elevational distribution pattern of soil microbes shifting across the treeline still remains unknown. Sampling of 140 plots with transect, we herein investigated soil bacterial distribution pattern from a temperate forest up to a subalpine meadow along an elevational gradient using Illumina sequencing. Our results revealed distinct elevational patterns of bacterial diversity above and below the treeline in responding to changes in soil conditions: a hollow elevational pattern in the forest (correlated with soil temperature, pH, and C:N ratio) and a significantly decreasing pattern in the meadow (correlated with soil pH, and available phosphorus). The bacterial community structure was also distinct between the forest and meadow, relating to soil pH in the forest and soil temperature in the meadow. Soil bacteria did not follow the distribution pattern of herb diversity, but bacterial community structure could be predicted by herb community composition. These results suggest that plant communities have an important influence on soil characteristics, and thus change the elevational distribution of soil bacteria. Our findings are useful for future assessments of climate change impacts on microbial community.
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http://dx.doi.org/10.1007/s11427-016-0072-6DOI Listing
November 2016

Downregulation of L1CAM inhibits proliferation, invasion and arrests cell cycle progression in pancreatic cancer cells

Exp Ther Med 2014 Apr 5;7(4):785-790. Epub 2014 Feb 5.

Department of Gastroenterology, Ruijin Hospital, Shanghai Jiaotong University, Shanghai, P.R. China.

The aim of the present study was to establish the effect of silencing L1 cell adhesion molecule (L1CAM) on the proliferation, invasion, cell cycle progression and apoptosis of pancreatic cancer cells, and to determine the potential molecular mechanisms that are involved. The human Capan-2 pancreatic cancer cell line was infected with lentivirus-mediated short hairpin RNA (shRNA) to target L1CAM. Cell proliferation and invasion were analyzed using cell counting kit-8 and Transwell assays, respectively, and cell cycle progression and apoptosis were analyzed using flow cytometry. L1CAM protein expression in Capan-2 cells decreased following shRNA-L1CAM infection. Furthermore, knockdown of L1CAM significantly inhibited cell proliferation and reduced the number of invasive cells, while increasing the percentage of cells in the G0/G1 phase (P<0.05). However, the effect on apoptosis was not identified to be statistically significant. In addition, L1CAM silencing may induce activation of p38/extracellular signal regulated kinase 1/2. Downregulation of L1CAM may inhibit proliferation, invasion and arrests cell cycle progression in pancreatic cancer via p38/ERK1/2 signal pathway, and therefore, L1CAM may serve as a potential target for gene therapy in pancreatic cancer.
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http://dx.doi.org/10.3892/etm.2014.1519DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3961134PMC
April 2014

Production of D-tagatose, a functional sweetener, utilizing alginate immobilized Lactobacillus fermentum CGMCC2921 cells.

Appl Biochem Biotechnol 2012 Feb 28;166(4):961-73. Epub 2011 Dec 28.

State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing, 210009, People's Republic of China.

D-tagatose is a ketohexose that can be used as a novel functional sweetener in foods, beverages, and dietary supplements. This study was aimed at developing a high-yielding D-tagatose production process using alginate immobilized Lactobacillus fermentum CGMCC2921 cells. For the isomerization from D-galactose into D-tagatose, the immobilized cells showed optimum temperature and pH at 65 °C and 6.5, respectively. The alginate beads exhibited a good stability after glutaraldehyde treatment and retained 90% of the enzyme activity after eight cycles (192 h at 65 °C) of batch conversion. The addition of borate with a molar ratio of 1.0 to D-galactose led to a significant enhancement in the D-tagatose yield. Using commercial β-galactosidase and immobilized L. fermentum cells, D-tagatose was successfully obtained from lactose after a two-step biotransformation. The relatively high conversion rate and productivity from D-galactose to D-tagatose of 60% and 11.1 g l⁻¹ h⁻¹ were achieved in a packed-bed bioreactor. Moreover, lactobacilli have been approved as generally recognized as safe organisms, which makes this L. fermentum strain an attracting substitute for recombinant Escherichia coli cells among D-tagatose production progresses.
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http://dx.doi.org/10.1007/s12010-011-9484-8DOI Listing
February 2012

Damage of the interstitial cells of Cajal and myenteric neurons causing ileus in acute necrotizing pancreatitis rats.

Surgery 2011 Feb 8;149(2):262-75. Epub 2010 Jun 8.

Laboratory of Stress Research, Department of Internal Medicine, Changhai Hospital, The Second Military Medical University, Shanghai, China.

Background: Small intestinal motility is impaired in acute necrotizing pancreatitis (ANP). The present study was designed to detect the impairment in small intestinal motility and to assess the role of interstitial cells of Cajal (ICC), myenteric neurons and the associated mechanism in the pathogenesis of ileus during experimentally induced acute pancreatitis.

Methods: ANP was induced by intraperitoneal injections of 30% L-ornithine at a dose of 3 g/kg at hourly intervals. The alterations of small intestine electrical activity--migrating myoelectric complexes (MMCs), and slow waves--were measured 24 hr after ANP induction. The spontaneous mechanical activity and the contractile response to ACh, KCl, tetrodotoxin (TTX) and the nitric oxide synthase (NOS) inhibitor NG-nitro-L-arginine (L-NNA) were evaluated by organ bath technique, and the morphologic alterations of the network of ICC, myenteric neurons and neuronal nitric oxide synthase (nNOS) immunoreactive cells were evaluated using the markers of c-Kit, PGP9.5, and nNOS, respectively. To demonstrate the deficiencies in enteric neuronal origin, we also measured nNOS expression in the muscular layer of ileum.

Results: L-ornithine-induced necrotizing pancreatitis manifests with multiple symptoms, including decreased amplitude of spontaneous contractions in small intestinal smooth muscle, declined contractile response to ACh, TTX, and L-NNA in vitro, disrupted MMC cycle length, decreased dominant frequency and dominant power of slow waves in vivo. Furthermore, the morphologic studies demonstrated the damage of ICC (ANP group versus control; P = .000), myenteric neurons (ANP group versus control; P = .001) and nNOS immunoreactive neurons (ANP group versus control; P = .000). We also observed a substantial loss in the expression of nNOS protein in muscular layer of the small intestine (ANP group versus control; P = .032).

Conclusion: Our results suggest that the pathogenesis of the small intestinal paralysis in ANP may be related to the deficiencies in ICC and nNOS neurons.
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http://dx.doi.org/10.1016/j.surg.2010.04.023DOI Listing
February 2011
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