Publications by authors named "Jianlei Wang"

25 Publications

  • Page 1 of 1

Effects of Heavy Metals/Metalloids and Soil Properties on Microbial Communities in Farmland in the Vicinity of a Metals Smelter.

Front Microbiol 2021 19;12:707786. Epub 2021 Aug 19.

National Engineering Laboratory of Biohydrometallurgy, GRINM Group Co., Ltd., Beijing, China.

Microorganisms play a fundamental role in biogeochemical cycling and are highly sensitive to environmental factors, including the physiochemical properties of the soils and the concentrations of heavy metals/metalloids. In this study, high-throughput sequencing of the 16S rRNA gene was used to study the microbial communities of farmland soils in farmland in the vicinity of a lead-zinc smelter. Proteobacteria, Acidobacteria, Actinobacteria, Bacteroidetes, and Gemmatimonadetes were the predominant phyla in the sites of interest. , , , , and were heavy metal-/metalloid-tolerant microbial groups with potential for bioremediation of the heavy metal/metalloid contaminated soils. However, the bacterial diversity was different for the different sites. The contents of heavy metal/metalloid species and the soil properties were studied to evaluate the effect on the soil bacterial communities. The Mantel test revealed that soil pH, total cadmium (T-Cd), and available arsenic played a vital role in determining the structure of the microbial communities. Further, we analyzed statistically the heavy metals/metalloids and the soil properties, and the results revealed that the microbial richness and diversity were regulated mainly by the soil properties, which correlated positively with organic matter and available nitrogen, while available phosphorus and available potassium were negatively correlated. The functional annotation of the prokaryotic taxa (FAPROTAX) method was used to predict the function of the microbial communities. Chemoheterotrophy and airborne chemoheterotrophy of the main microbial community functions were inhibited by soil pH and the heavy metals/metalloids, except in the case of available lead. Mantel tests revealed that T-Cd and available zinc were the dominant factors affecting the functions of the microbial communities. Overall, the research indicated that in contaminated soils, the presence of multiple heavy metals/metalloids, and the soil properties synergistically shaped the structure and function of the microbial communities.
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http://dx.doi.org/10.3389/fmicb.2021.707786DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8417379PMC
August 2021

Laparoscopic versus open surgery for hilar cholangiocarcinoma: a retrospective cohort study on short-term and long-term outcomes.

Surg Endosc 2021 Aug 16. Epub 2021 Aug 16.

Department of Organ Transplantation, Qilu Hospital, Cheeloo College of Medicine, Shandong University, 107 Wenhuaxi Road, Jinan, 250012, Shandong, China.

Background: Laparoscopic surgery (LS) for hilar cholangiocarcinoma (HCCa) remains under development, and its feasibility and safety remain controversial. This study therefore evaluated the outcomes of this technique and compared them to those of open surgery (OS).

Methods: In total, 149 patients underwent surgical resection for HCCa at our center between February 2017 and September 2020. After screening and propensity score matching, 47 OS group patients and 20 LS group patients remained, and their baseline characteristics, pathologic findings, surgical outcomes, and long-term outcomes were compared.

Result: The baseline characteristics and pathologic findings were comparable between the two groups. The mean incision length was longer in the OS group than in the LS group (21.0 cm vs. 13.2 cm, P < 0.001). No significant differences were observed in the other surgical outcomes between the two groups. Regarding long-term outcomes, the overall survival rate and disease-free survival rate of the OS group were significantly higher than those of the LS group (P = 0.0057, P = 0.043). However, the two groups had significantly different follow-up times (19.2 months vs. 14.7 months, P = 0.041).

Conclusion: LS for HCCa is technically achievable, and our study revealed that it is equivalent to OS in terms of short-term outcomes but was poorer in terms of long-term outcomes.
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http://dx.doi.org/10.1007/s00464-021-08686-6DOI Listing
August 2021

A Review of Conductive Carbon Materials for 3D Printing: Materials, Technologies, Properties, and Applications.

Materials (Basel) 2021 Jul 13;14(14). Epub 2021 Jul 13.

Innovation Center for Textile Science and Technology, State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China.

Carbon material is widely used and has good electrical and thermal conductivity. It is often used as a filler to endow insulating polymer with electrical and thermal conductivity. Three-dimensional printing technology is an advance in modeling and manufacturing technology. From the forming principle, it offers a new production principle of layered manufacturing and layer by layer stacking formation, which fundamentally simplifies the production process and makes large-scale personalized production possible. Conductive carbon materials combined with 3D printing technology have a variety of potential applications, such as multi-shape sensors, wearable devices, supercapacitors, and so on. In this review, carbon black, carbon nanotubes, carbon fiber, graphene, and other common conductive carbon materials are briefly introduced. The working principle, advantages and disadvantages of common 3D printing technology are reviewed. The research situation of 3D printable conductive carbon materials in recent years is further summarized, and the performance characteristics and application prospects of these conductive carbon materials are also discussed. Finally, the potential applications of 3D printable conductive carbon materials are concluded, and the future development direction of 3D printable conductive carbon materials has also been prospected.
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http://dx.doi.org/10.3390/ma14143911DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8307564PMC
July 2021

Functional redundancy and specific taxa modulate the contribution of prokaryotic diversity and composition to multifunctionality.

Mol Ecol 2021 06 18;30(12):2915-2930. Epub 2021 May 18.

Key Laboratory of Pollinating Insect Biology, Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing, China.

Observational and experimental evidence has revealed the functional importance of microbial diversity. However, the effects of microbial diversity loss on ecosystem functions are not consistent across studies, which are probably tempered by microbial functional redundancy, specific taxa and functions evaluated. Here we conducted diversity manipulation experiments in two independent soils with distinct prokaryotic communities, and investigated how the initial community traits (e.g., distinct functional redundancy and taxonomic composition) modulate the contribution of prokaryotic diversity loss and composition shift to eight ecosystem functions related to soil nutrient cycling. We found that diversity loss impaired three functions (potential nitrification rate, N -fixation activity and phosphatase) and multifunctionality only in the communities with low functional redundancy, but all examined functions were unaffected in the communities with high functional redundancy. All significantly affected functions belonged to specialized functions, while the broad function (soil basal respiration) was unaffected. Moreover, prokaryotic composition explained more functional variation than diversity, which was ascribed to the crucial role of specific taxa that influence particular functions. Taken together, this study provides empirical evidence for identifying the mechanism underlying the ecosystem response to changes in microbial community, with implications for improving the prediction of ecosystem process models and managing microbial communities to promote ecosystem services.
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http://dx.doi.org/10.1111/mec.15935DOI Listing
June 2021

Clinical Application of a Modified Double Purse-String Continuous Suture Technique for Pancreaticojejunostomy: Reliable for Laparoscopic Surgery and Small Size Main Pancreatic Duct.

Biomed Res Int 2021 13;2021:6676999. Epub 2021 Mar 13.

Department of General Surgery, Qilu Hospital, Shandong University, No. 107, Wenhua Xi Road, Jinan 250012, China.

Background: The technical challenge of pancreatojejunostomy (PJ) is the greatest barrier for surgeons to complete pancreatoduodenectomy (PD). The authors present an easy-to-master PJ anastomosis technique with limited technical requirements. This technique uses two layers of sutures and double purse-string sutures to complete the entire anastomosis. This anastomosis technique has achieved good results in laparoscopic surgery (LS) and small size main pancreatic duct (MPD).

Methods: From February 2015 to August 2020, 63 patients who met the surgical indications underwent a modified double purse-string continuous suture pancreaticojejunostomy technique in our center. We collected patient demographic characteristics and perioperative outcomes and analyzed these data.

Results: A total of 63 patients underwent PD using our new anastomosis technique. Thirty-eight patients underwent LS, and 26 patients had a small MPD (<3 mm). The median operative time (OT) was 270 min, and the median estimated blood loss (EBL) was 200 ml. Ten patients had grade B postoperative pancreatic fistula (POPF), while no patients had grade C POPF. No 90-day mortality was observed. There were significant differences in the OT and postoperative hospital stay (PHS) among groups with different surgical procedures, while there were no significant differences among groups with different MPD sizes. Neither the surgical procedure nor the MPD size affected early postoperative complications.

Conclusion: This new technique can not only reduce the incidence of POPF but also is reliable for LS and surgeries with small size MPD. Therefore, this technique is worthy of clinical promotion and application in the future.
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http://dx.doi.org/10.1155/2021/6676999DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7984902PMC
May 2021

Lab-scale evaluation of the microbial bioremediation of Cr(VI): contributions of biosorption, bioreduction, and biomineralization.

Environ Sci Pollut Res Int 2021 May 8;28(18):22359-22371. Epub 2021 Jan 8.

National Engineering Laboratory of Biohydrometallurgy, GRINM Group Corporation Limited, Beijing, 100088, China.

Bioremediation of Cr(VI) by microorganisms has attracted immense research interests. There are three different mechanisms for bioremediation of Cr(VI): biosorption, bioreduction, and biomineralization. Identifying the relative contributions of these different mechanisms to Cr(VI) bioremediation can provide valuable information to enhance the final result. This article explores the corresponding contributions of different mechanisms in the Cr(VI) bioremediation process. To obtain a deeper understanding of each bioremediation mechanism, the corresponding precipitation products were analyzed via different methods. Fourier transform infrared spectrometer (FTIR) analysis showed that Cr(VI) was adsorbed by functional groups in EPS to form a chelate compound. X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) analysis determined that the stable Cr(III) compounds and mineral crystals which contain chromium gradually formed during the bioremediation process. High-throughput sequencing technology was applied to monitor microbial community succession. The results showed that the total removal rate of Cr(VI) reached 77.64% in 56 days in 100 mg/L Cr(VI). Bioreduction was the major contributor to the final result, followed by biosorption and biomineralization; their proportions are 69.61%, 19.16%, and 11.23%, respectively. Besides, the high-throughput sequencing data indicated that reductive microorganisms were the dominant flora and that the relative abundance of different reductive microorganism types changes significantly. This work has clarified the contributions of different mechanisms during Cr(VI) bioremediation process and provided a new enhancement strategy for Cr(VI) bioremediation.Graphical abstract.
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http://dx.doi.org/10.1007/s11356-020-11852-3DOI Listing
May 2021

Effect of POSS-Modified Montmorillonite on Thermal, Mechanical, and Electrical Properties of Unsaturated Polyester Nanocomposites.

Polymers (Basel) 2020 Sep 7;12(9). Epub 2020 Sep 7.

CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China.

Montmorillonite (MMT) displays excellent cohesion with an unsaturated polyester (UP) matrix to generate a material which exhibits an extensive range of commercial applications. The organic modification of MMT using polyhedral oligomeric silsesquioxanes (POSS) and the effect of POSS-MMT on the thermal, mechanical, and electrical properties of UP are reported here. Transmission electron microscopy (TEM) images were used to characterize the modification of MMT using POSS. Modified MMT (POSS-MMT) was incorporated, at different wt.% (0.5, 1, 3, 5), into UP via in-situ polymerization. The presence of POSS-MMT enhanced the characteristic properties of UP as a consequence of good dispersion in the polymer matrix. Scanning electron microscopy (SEM) images support effective POSS-MMT dispersion leading to tensile strength enhancement of a UP/POSS-MMT nanocomposite (3 wt.% POSS-MMT) by 54.7% as compared to that for unmodified UP. TGA displays a 35 °C improvement of thermal stability (10% mass loss) at 5% POSS-MMT incorporation, while the electrical conductivity is improved by 10 S/m (3 wt.% POSS-MMT) in comparison to that for unmodified UP. The conventional obstacle of UP associated with shrinkage weight loss during curing seems to be moderated with POSS-MMT incorporation (3%) resulting in a 27.8% reduction in shrinkage weight loss. These fabricated nanocomposites expand the versatility of UP as a high-performance material owing to enhancements of properties.
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http://dx.doi.org/10.3390/polym12092031DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7564685PMC
September 2020

High-efficiency Er-doped yttrium gallium garnet laser resonantly pumped by a laser diode at 1.47  µm.

Opt Lett 2020 Aug;45(15):4361-4364

The spectroscopic and laser properties of an -doped yttrium gallium garnet crystal, (YGG), are studied. The stimulated emission cross section is 1.4×10 at 1.65 µm. A continuous-wave laser resonantly pumped by a laser diode at 1.47 µm is demonstrated, delivering a maximum output power of 3.34 W. Benefiting from the low phonon energy of the YGG host, the corresponding slope efficiency is as high as ∼42. To the best of our knowledge, this is the highest slope efficiency from the laser-diode resonantly pumped Er lasers at room temperature in the 1.6 µm spectral range.
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http://dx.doi.org/10.1364/OL.401155DOI Listing
August 2020

Novel Unsaturated Polyester Nanocomposites via Hybrid 3D POSS-Modified Graphene Oxide Reinforcement: Electro-Technical Application Perspective.

Nanomaterials (Basel) 2020 Feb 3;10(2). Epub 2020 Feb 3.

CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China.

The latest trends in technologies has shifted the focus to developing innovative methods for comprehensive property enhancement of the polymer composites with facile and undemanding experimental techniques. This work reports an elementary technique to fabricate high-performance unsaturated polyester-based nanocomposites. It focuses on the interactive effect of polyhedral oligomeric silsesquioxanes (POSS)-functionalized graphene oxide (GO) within the unsaturated polymermatrix. The hybrid framework of POSS-functionalized graphene oxide has been configured via peptide bonding between the aminopropyl isobutyl POSS and graphene oxide. The synergistic effect of POSS and graphene oxide paved the way for a mechanism to inculcate a hybrid framework within the unsaturated polyester (UP) via in situ polymerization to develop UP/GO-POSS nanocomposites. The surface-appended POSS within the graphene oxide boosted its dispersion in the UP matrix, furnishing an enhancement in tensile strength of the UP/GO-POSS composites by 61.9%, thermal decomposition temperature (10% mass loss) by 69.8 °C and electrical conductivity by 10 S/m, in contrast to pure UP. In particular, the homogenous influence of the POSS-modified GO could be vindicated in the surging of the limiting oxygen index (%) in the as-prepared nanocomposites. The inclusive property amelioration vindicates the use of fabricated nanocomposites as high-performance nanomaterials in electrotechnical applications.
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http://dx.doi.org/10.3390/nano10020260DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7075121PMC
February 2020

A Novel Approach to Enhance Mechanical and Thermal Properties of SLA 3D Printed Structure by Incorporation of Metal-Metal Oxide Nanoparticles.

Nanomaterials (Basel) 2020 Jan 27;10(2). Epub 2020 Jan 27.

CAS Key Laboratory of Design and Assembly of Functional Nanostructure, and Fujian Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China.

Silver (Ag) ornamented TiO semiconducting nanoparticles were synthesized through the sol-gel process to be utilized as nanofillers with photo resin to enhance the mechanical and thermal properties of stereolithography 3D printed objects. The as-prepared Ag-TiO nanoparticles (Ag-TNP) were typified and qualified by XRD, XPS, Raman, and FESEM; TEM analysis dissected the morphologies. The enhancement in the tensile and flexural strengths of SLR/Ag-TNP nanocomposites was noted as 60.8% and 71.8%, respectively, at the loading content of 1.0% / Ag-TNP within the SLR (stereolithography resin) matrix. Similarly, the thermal conductivity and thermal stability were observed as higher for SLR/Ag-TNP nanocomposites, equated to neat SLR. The nanoindentation investigation shows an excerpt hike in reduced modulus and hardness by the inclusion of Ag-TNP. The resulted thermal analysis discloses that the introduction of Ag-TNP can appreciably augment the glass transition temperature (T), and residual char yield of SLR nanocomposites remarkably. Hence, the significant incorporation of as-prepared Ag-TNP can act as effective nanofillers to enhance the thermal and mechanical properties of photo resin.
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http://dx.doi.org/10.3390/nano10020217DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7074857PMC
January 2020

High-energy 2  µm pulsed vortex beam excitation from a Q-switched Tm:LuYAG laser.

Opt Lett 2020 Feb;45(3):722-725

We report on the first, to the best of our knowledge, direct generation of pulsed vortex beams at 2 µm from a ${ Q}$Q-switched Tm:LuYAG laser. High-energy Laguerre-Gaussian (${{\rm LG}_{0,l}}$LG) pulsed laser beams with well-defined handedness are selectively excited through spatially matched pump gain distribution and asymmetric cavity loss without using any intracavity handedness-selective optical elements. Pulse energies of 1.48 mJ for the ${{\rm LG}_{0, + 1}}$LG mode and 1.51 mJ for the ${{\rm LG}_{0, - 1}}$LG mode, respectively, are achieved at a repetition rate of 500 Hz. The pulsed laser beams with helical wavefronts are potentially useful for studying orbital angular momentum transformation dynamics, generation of mid-IR vortex beams, and nanostructuring of organic materials.
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http://dx.doi.org/10.1364/OL.384201DOI Listing
February 2020

Enhanced Mechanical and Thermal Properties of Stereolithography 3D Printed Structures by the Effects of Incorporated Controllably Annealed Anatase TiO Nanoparticles.

Nanomaterials (Basel) 2020 Jan 1;10(1). Epub 2020 Jan 1.

CAS Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China.

Fabrication of low-cost, durable and efficient metal oxide nanocomposites were successfully synthesized and reinforced with photo-resin via 3-dimensional printing. Here, we put forward a novel approach to enhance the mechanical and thermal behaviors of stereolithography (SLA) 3D printed architecture by adding TiO nanoparticles (TNPs) in different crystalline phases (anatase and rutile), which were obtained at different annealing temperatures from 400 °C to 1000°C. The heat-treated anatase TNPs were scrutinized by X-ray diffraction(XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, diffusive reflectance spectroscopy (DRS), and transmission electron microscopy (TEM) analysis. Among all the samples, at 800 °C, annealed anatase TNPs exposed a highly crystalline anatase phase, having a low energy bandgap and a comparably high tensile strength (47.43 MPa) and high elastic modulus (2.261 GPa) for the 3D printed samples, showing improvement by 103% and 32%, respectively, compared with the printed pristine stereolithography resin (SLR) sample. Moreover, enhanced storage modulus and tan values were achieved the better interfacial interactions between the incorporated nanofillers and the SLR matrix. In addition to this, enhanced thermal conductivity and thermal stability of the SLR matrix were also noted. The low energy bandgap and nanoscale size of the fillers helped to achieve good dispersion and allowed the UV light to penetrate at a maximum depth through the photo resin.
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http://dx.doi.org/10.3390/nano10010079DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7022956PMC
January 2020

Adaptive responses of comammox Nitrospira and canonical ammonia oxidizers to long-term fertilizations: Implications for the relative contributions of different ammonia oxidizers to soil nitrogen cycling.

Sci Total Environ 2019 Jun 28;668:224-233. Epub 2019 Feb 28.

State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address:

The new discovery of complete ammonia oxidizers (comammox), single organisms capable of oxidizing ammonia into nitrate, redefined the traditional view of nitrification. However, little is known about the relative contributions of comammox and other nitrifiers to nitrification, particularly in agricultural soils with long-term intensive input of nutrients. Herein, we investigated the communities of ammonia-oxidizing bacteria (AOB), ammonia-oxidizing archaea (AOA) and comammox Nitrospira in agricultural soils under nutrients input gradient of nitrogen (0-675 kg N ha year), phosphorus (0-405 kg PO ha year), and potassium (0-675 kg KO ha year) fertilizers for 19 years. The results showed that N and K fertilizers input significantly (P < 0.05) increased the AOB-amoA gene abundance, while AOA were not as sensitive as AOB. The comammox-amoA gene copies were increased in all fertilizer treatments and was significantly correlated (P < 0.05) with the amount of N fertilizer added. Terminal restriction fragment length polymorphism (T-RFLP) combined with clone-library assays of comammox-amoA gene showed that increasing gradient of nutrients input increased the relative abundance of 73 bp T-RF (assigned to Clade A) but decreased the relative abundance of 198 bp T-RF (representing Clade B). Correlation analyses and stepwise linear regression analyses demonstrated that AOB were the dominate contributors to soil potential nitrification, while comammox Nitrospira did not play a significant role (P > 0.05). This study provided insights into the adaptive responses of comammox Nitrospira and canonical ammonia oxidizers to long-term fertilizations and their relative contributions to potential nitrification in arable soils.
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http://dx.doi.org/10.1016/j.scitotenv.2019.02.427DOI Listing
June 2019

Mechanically robust nanocomposites from screen-printable polymer/graphene nanosheet pastes.

Nanoscale 2019 Jan;11(5):2343-2354

CAS Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, People's Republic of China.

Innovative methods for producing graphene-based polymer nanocomposites with excellent mechanical robustness have become a focus for their practical utilization, existing solutions suffer from drawbacks such as limited laboratory-scale fabrication, affordability, and inadequate processability. To address these issues, we proposed a screen printing approach utilizing formulated graphene-modified water-based printable pastes to achieve inexpensive and scalable manufacturing of graphene-reinforced polymer nanocomposites. Leveraging this simple and versatile manufacturing process, mass production, as well as personalized-patterned bulk materials, can be efficiently produced using easily obtainable substrates. The surface-tailored graphene (PEI-rGO) can improve the dispersion quality and strengthen the interfacial bonding with a waterborne polyurethane (WPU) matrix, yielding an optimized enhancement effect and enhancing the tensile strength and Young's modulus about 9.46 and 19.8 times higher than those of the pure WPU, respectively. In particular, their utility as an anti-wear modifier through direct printing on textile and wear-reduction performance were investigated. Our study establishes screen printing as a general strategy to achieve facile fabrication of polymer nanocomposites at an industrial-scale in an economically viable manner, which can to a great extent bridge the gap between scientific research and real-world applications.
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http://dx.doi.org/10.1039/c8nr08933gDOI Listing
January 2019

High-performance Ho:YAG single-crystal fiber laser in-band pumped by a Tm-doped all-fiber laser.

Opt Lett 2019 Jan;44(2):455-458

We report on, to the best of our knowledge, the first Q-switched single-crystal fiber (Ho:YAG SCF) laser in the 2 μm spectral range, in-band pumped by a Tm-doped all-fiber laser. A continuous-wave laser with 12.5 W output power and Q-switched laser with 1.44 mJ pulse energy and 7.5 ns pulse duration at a repetition rate of 1 kHz were demonstrated. The high laser performance is attributed to the high gain, suppressed nonlinear effects, and easy thermal management which benefited from the unique geometric construction of the SCF.
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http://dx.doi.org/10.1364/OL.44.000455DOI Listing
January 2019

790  W incoherent beam combination of a Tm-doped fiber laser at 1941  nm using a 3 × 1 signal combiner.

Appl Opt 2018 Jul;57(20):5574-5577

In this paper, we report on a high-power incoherent beam combination of three Tm-doped fiber amplifiers at 1941 nm based on a 3×1 signal combiner. An output power of 790 W is achieved from the signal combiner with a slope efficiency of 52.2% with respect to the launched pump power and a beam quality factor M of 2.7. The beam quality factor is close to the theoretical limit of the 3×1 fiber combiner. The parameters of the amplifier are optimized to increase the laser efficiency. Our analyses show that this structure is sufficient to support kilowatt-level output power while maintaining the high beam quality.
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http://dx.doi.org/10.1364/AO.57.005574DOI Listing
July 2018

Influence of nitrogen and phosphorus additions on N-fixation activity, abundance, and composition of diazotrophic communities in a Chinese fir plantation.

Sci Total Environ 2018 Apr 10;619-620:1530-1537. Epub 2017 Nov 10.

Guangdong Provincial Bioengineering Institute (Guangzhou Sugarcane Industry Research Institute), Guangdong Key Laboratory of Sugarcane Improvement and Biorefinery, Guangzhou 510316, China. Electronic address:

Although biological nitrogen (N) fixation (BNF) is an important N input process in subtropical forest ecosystems, how the diazotrophic communities related to this process respond to N and phosphorus (P) inputs is largely unknown. We investigated the effects of exogenous N and/or P inputs on N-fixation activity, diazotrophic abundance and community composition using a continuous application of fertilizers over 5years experiment in a Chinese fir plantation. The fertilization regimes included control (CK), P treatment (P), low N addition treatment (N1), high N addition treatment (N2), low N and P addition treatment (N1P) and high N with P addition treatment (N2P). N-fixation activity was determined using the acetylene reduction assay (ARA). Quantitative PCR and Illumina Miseq sequencing of nifH gene were performed to analyze diazotrophic abundance and community composition, respectively. Our results showed that P addition increased N-fixation activity and nifH gene abundance by 189.07nmol CH and 1.02×10copiesg dry soil, respectively, while were reduced by 1.19nmol CH and 2.04×10copiesg dry soil when N was added. The application of P with low N (N1P) effectively alleviated the inhibitory effect of N input on N-fixation activity. N-related treatments resulted in significant decreases in operational taxonomic unit (OTU) richness and shifts in diazotrophic community structure. N-fixation activity and nifH gene abundance were strongly and positively correlated with soil pH and negatively correlated with mineral N (NH-N and NO-N) contents, while mineral N concentrations rather than soil pH appeared to be the main factor altering diazotrophic community structure. These results revealed that P addition played a positive role in regulating biological nitrogen fixation in subtropical forest ecosystems.
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http://dx.doi.org/10.1016/j.scitotenv.2017.10.064DOI Listing
April 2018

The full annual carbon balance of a subtropical coniferous plantation is highly sensitive to autumn precipitation.

Sci Rep 2017 08 30;7(1):10025. Epub 2017 Aug 30.

State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu, 610065, China.

Deep understanding of the effects of precipitation on carbon budgets is essential to assess the carbon balance accurately and can help predict potential variation within the global change context. Therefore, we addressed this issue by analyzing twelve years (2003-2014) of observations of carbon fluxes and their corresponding temperature and precipitation data in a subtropical coniferous plantation at the Qianyanzhou (QYZ) site, southern China. During the observation years, this coniferous ecosystem experienced four cold springs whose effects on the carbon budgets were relatively clear based on previous studies. To unravel the effects of temperature and precipitation, the effects of autumn precipitation were examined by grouping the data into two pools based on whether the years experienced cold springs. The results indicated that precipitation in autumn can accelerate the gross primary productivity (GPP) of the following year. Meanwhile, divergent effects of precipitation on ecosystem respiration (Re) were found. Autumn precipitation was found to enhance Re in normal years but the same regulation was not found in the cold-spring years. These results suggested that for long-term predictions of carbon balance in global climate change projections, the effects of precipitation must be considered to better constrain the uncertainties associated with the estimation.
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http://dx.doi.org/10.1038/s41598-017-10485-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5577199PMC
August 2017

Differences in Fine-Root Biomass of Trees and Understory Vegetation among Stand Types in Subtropical Forests.

PLoS One 2015 5;10(6):e0128894. Epub 2015 Jun 5.

Qianyanzhou Ecological Station, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China.

Variation of total fine-root biomass among types of tree stands has previously been attributed to the characteristics of the stand layers. The effects of the understory vegetation on total fine-root biomass are less well studied. We examined the variation of total fine-root biomass in subtropical tree stands at two sites of Datian and Huitong in China. The two sites have similar humid monsoon climate but different soil organic carbon. One examination compared two categories of basal areas (high vs. low basal area) in stands of single species. A second examination compared single-species and mixed stands with comparable basal areas. Low basal area did not correlate with low total fine-root biomass in the single-species stands. The increase in seedling density but decrease in stem density for the low basal area stands at Datian and the quite similar stand structures for the basal-area contrast at Huitong helped in the lack of association between basal area and total fine-root biomass at the two sites, respectively. The mixed stands also did not yield higher total fine-root biomasses. In addition to the lack of niche complementarity between tree species, the differences in stem and seedling densities and the belowground competition between the tree and non-tree species also contributed to the similarity of the total fine-root biomasses in the mixed and single-species stands. Across stand types, the more fertile site Datian yielded higher tree, non-tree and total fine-root biomasses than Huitong. However, the contribution of non-tree fine-root biomass to the total fine-root biomass was higher at Huitong (29.4%) than that at Datian (16.7%). This study suggests that the variation of total fine-root biomass across stand types not only was associated with the characteristics of trees, but also may be highly dependent on the understory layer.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0128894PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4457824PMC
February 2016

[Investigation regarding the correlation between hydroxyethyl starch administration and acute kidney injury in critically ill patients].

Zhonghua Wei Zhong Bing Ji Jiu Yi Xue 2015 May;27(5):338-42

Department of Critical Care Medicine, People's Hospital of Huangshan, Wannan Medical College, Huangshan 245000, Anhui, China.Corresponding author: Zhang Mucheng, Email:

Objective: To explore the risk factors of the occurrence of acute kidney injury (AKI) in critically ill patients, and to investigate the effect of hydroxyethyl starch (HES) on renal function in these patients.

Methods: A prospective investigation was conducted. Critically ill patients admitted to Department of Critical Care Medicine of People's Hospital of Huangshan, Wannan Medical College from March 2012 to October 2013 were enrolled. For all the patients under observation, the following data were collected: demography, comorbidities, clinical presentation, severity of illness, and the use of blood product and drugs. All patients were divided into AKI group and non-AKI group by means of Acute Kidney Injury Network (AKIN) criteria, then the risk factors of AKI were investigated by means of univariate and multivariate logistic regression analysis. The effect of HES 130/0.4 administration on renal function in critically ill patients was evaluated.

Results: 314 patients were enrolled for study out of 1 152 patients admitted. Among these patients enrolled, 89 of them were found to suffer from AKI. AKI was classified as stage 1 in 59 patients, stage 2 in 19 patients, and stage 3 in 11 patients. It was shown by the univariate analysis that 12 variables were the risk factors of AKI, including age, hypertension, diabetes mellitus, acute physiology and chronic health evaluation II (APACHEII) score, sequential organ failure assessment (SOFA) score, coagulation SOFA score, neurological SOFA score, cardiovascular SOFA score, blood pH on intensive care unit (ICU) admission, blood glucose on ICU admission, accumulating dose of HES, and presence of shock (P < 0.05 or P < 0.01). However, HES administration and daily maximum dose of HES were not the risk factors of AKI in critically ill patients (both P > 0.05). Using the multivariate logistic regression analysis, it was shown that total SOFA score [ odds ratio (OR) = 1.20, 95% confidence interval (95%CI) = 1.09-1.32, P < 0.001 ], hypertension (OR = 2.44, 95%CI = 1.22-4.89, P = 0.012), blood glucose level on ICU admission (OR = 1.85, 95%CI = 1.32-2.59, P < 0.001), and presence of shock (OR = 3.81, 95%CI = 1.93-7.53, P < 0.001) were independent predictors of AKI in critically ill patients, however, the cumulative dose of HES was not independent risk factor for AKI (OR = 0.77, 95%CI = 0.68-0.87, P < 0.001).

Conclusions: Total SOFA score, hypertension, blood glucose level on ICU admission, and presence of shock were independent risk factors for AKI in critically ill patients. HES administration may not be a causative factor of an increased risk of AKI in the ICU.
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http://dx.doi.org/10.3760/cma.j.issn.2095-4352.2015.05.004DOI Listing
May 2015

Complete nucleotide sequence of Klebsiella phage P13 and prediction of an EPS depolymerase gene.

Virus Genes 2015 Feb 13;50(1):118-28. Epub 2014 Nov 13.

College of Food Science and Engineering, Ocean University of China, 5 Yushan Road, Qingdao, 266003, Shandong, China.

The complete genome of Klebsiella phage P13 was sequenced and analyzed. Bacteriophage P13 has a double-stranded linear DNA with a length of 45,976 bp and a G+C content of 51.7 %, which is slightly lower than that of Klebsiella pneumoniae KCTC 2242. The codon biases of phage P13 are very similar to those of SP6-like phages and K. pneumoniae KCTC 2242. Bioinformatics analysis shows that the phage P13 genome has 282 open reading frames (ORFs) that are greater than 100 bp in length, and 50 of these ORFs were identified as predicted genes with an average length of 833 bp. Among these genes, 41 show homology to known proteins in the GenBank database. The functions of the 24 putative proteins were investigated, and 13 of these were found to be highly conserved. According to the homology analysis of the 50 predicted genes and the whole genome, phage P13 is homologous to SP6-like phages. Furthermore, the morphological characteristics of phage P13 suggest that it belongs to the SP6-like viral genus of the Podoviridae subfamily Autographivirinae. Two hypothetical genes encoding an extracellular polysaccharide depolymerase were predicted using PSI-BLAST. This analysis serves as groundwork for further research and application of the enzyme.
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http://dx.doi.org/10.1007/s11262-014-1138-9DOI Listing
February 2015

Understory vegetation leads to changes in soil acidity and in microbial communities 27 years after reforestation.

Sci Total Environ 2015 Jan 26;502:280-6. Epub 2014 Sep 26.

Qianyanzhou Ecological Station, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.

Experiments with potted plants and removed understories have indicated that understory vegetation often affects the chemical and microbial properties of soil. In this study, we examined the mechanism and extent of the influence of understory vegetation on the chemical and microbial properties of soil in plantation forests. The relationships between the vegetational structure (diversity for different functional layers, aboveground biomass of understory vegetation, and species number) and soil properties (pH, microbial community structure, and levels of soil organic carbon, total nitrogen, and inorganic nitrogen) were analyzed across six reforestation types (three pure needleleaf forests, a needle-broadleaf mixed forest, a broadleaf forest, and a shrubland). Twenty-seven years after reforestation, soil pH significantly decreased by an average of 0.95 across reforestation types. Soil pH was positively correlated with the aboveground biomass of the understory. The levels of total, bacterial, and fungal phospholipid fatty acids, and the fungal:bacterial ratios were similar in the shrubland and the broadleaf forest. Both the aboveground biomass of the understory and the diversity of the tree layer positively influenced the fungal:bacterial ratio. Improving the aboveground biomass of the understory could alleviate soil acidification. An increase in the aboveground biomass of the understory, rather than in understory diversity, enhanced the functional traits of the soil microbial communities. The replacement of pure plantations with mixed-species stands, as well as the enhancement of understory recruitment, can improve the ecological functions of a plantation, as measured by the alleviation of soil acidification and increased fungal dominance.
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http://dx.doi.org/10.1016/j.scitotenv.2014.09.018DOI Listing
January 2015

Production of a water-soluble fertilizer containing amino acids by solid-state fermentation of soybean meal and evaluation of its efficacy on the rapeseed growth.

J Biotechnol 2014 Oct 22;187:34-42. Epub 2014 Jul 22.

College of Food Science and Engineering, Ocean University of China, 5 Yushan Road, Qingdao 266003, China. Electronic address:

Soybean meal is a by-product of soybean oil extraction and contains approximately 44% protein. We performed solid-state fermentation by using Bacillus subtilis strain N-2 to produce a water-soluble fertilizer containing amino acids. Strain N-2 produced a high yield of protease, which transformed the proteins in soybean meal into peptide and free amino acids that were dissolved in the fermentation products. Based on the Plackett-Burman design, the initial pH of the fermentation substrate, number of days of fermentation, and the ratio of liquid to soybean meal exhibited significant effects on the recovery of proteins in the resulting water-soluble solution. According to the predicted results of the central composite design, the highest recovery of soluble proteins (99.072%) was achieved at the optimum conditions. Under these conditions, the resulting solution contained 50.42% small peptides and 7.9% poly-γ-glutamic acid (γ-PGA). The water-soluble fertilizer robustly increased the activity of the rapeseed root system, chlorophyll content, leaf area, shoot dry weight, root length, and root weight at a concentration of 0.25% (w/v). This methodology offers a value-added use of soybean meal.
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http://dx.doi.org/10.1016/j.jbiotec.2014.07.015DOI Listing
October 2014

Production of a water-soluble fertilizer containing amino acids by solid-state fermentation of soybean meal and evaluation of its efficacy on the rapeseed growth.

J Biotechnol 2014 Oct 22;187:34-42. Epub 2014 Jul 22.

College of Food Science and Engineering, Ocean University of China, 5 Yushan Road, Qingdao 266003, China. Electronic address:

Soybean meal is a by-product of soybean oil extraction and contains approximately 44% protein. We performed solid-state fermentation by using Bacillus subtilis strain N-2 to produce a water-soluble fertilizer containing amino acids. Strain N-2 produced a high yield of protease, which transformed the proteins in soybean meal into peptide and free amino acids that were dissolved in the fermentation products. Based on the Plackett-Burman design, the initial pH of the fermentation substrate, number of days of fermentation, and the ratio of liquid to soybean meal exhibited significant effects on the recovery of proteins in the resulting water-soluble solution. According to the predicted results of the central composite design, the highest recovery of soluble proteins (99.072%) was achieved at the optimum conditions. Under these conditions, the resulting solution contained 50.42% small peptides and 7.9% poly-γ-glutamic acid (γ-PGA). The water-soluble fertilizer robustly increased the activity of the rapeseed root system, chlorophyll content, leaf area, shoot dry weight, root length, and root weight at a concentration of 0.25% (w/v). This methodology offers a value-added use of soybean meal.
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http://dx.doi.org/10.1016/j.jbiotec.2014.07.015DOI Listing
October 2014

DNA helicase activity of the RecD protein from Deinococcus radiodurans.

J Biol Chem 2004 Dec 4;279(50):52024-32. Epub 2004 Oct 4.

Department of Chemistry & Biochemistry, University of Maryland, College Park, Maryland 20742, USA.

The bacterium Deinococcus radiodurans is extremely resistant to high levels of DNA-damaging agents, including gamma rays and ultraviolet light that can lead to double-stranded DNA breaks. Surprisingly, the organism does not appear to have a RecBCD enzyme, an enzyme that is critical for double-strand break repair in many other bacteria. The D. radiodurans genome does encode a protein whose closest characterized homologues are RecD subunits of RecBCD enzymes in other bacteria. We have purified this novel D. radiodurans RecD protein and characterized its biochemical activities. The D. radiodurans RecD protein is a DNA helicase that unwinds short (20 base pairs) DNA duplexes with either a 5'-single-stranded tail or a forked end, but not blunt-ended or 3'-tailed duplexes. Duplexes with 10-12 nucleotide (nt) 5'-tails are good unwinding substrates and are bound tightly, while DNA with shorter tails (4-8 nt) are poor unwinding substrates and are bound much less tightly. The RecD protein is much less efficient at unwinding slightly longer substrates (52 or 76 base pairs, with 12 nt 5'-tails). Unwinding of the longer substrates is stimulated somewhat (4-5-fold) by the single-stranded DNA-binding protein from D. radiodurans. These results show that the D. radiodurans RecD protein is a DNA helicase with 5'-3' polarity and low processivity.
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http://dx.doi.org/10.1074/jbc.M408645200DOI Listing
December 2004
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