Publications by authors named "Wenkai Wang"

41 Publications

A new species of Trachystolodes Breuning, 1943 from Central China (Coleoptera, Cerambycidae, Lamiinae).

Zootaxa 2021 Mar 11;4942(1):zootaxa.4942.1.8. Epub 2021 Mar 11.

College of Agriculture, Yangtze University, Jingzhou, Hubei, 434025, P. R. China.

A new species, Trachystolodes tianjialini sp. nov., from Houhe National Nature Reserve, Hubei, China, is described and illustrated.
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http://dx.doi.org/10.11646/zootaxa.4942.1.8DOI Listing
March 2021

Allele-based analysis revealed the critical functions of region 277-297 in the NorA efflux pump of Staphylococcus aureus.

J Antimicrob Chemother 2021 Mar 3. Epub 2021 Mar 3.

State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao 266237, P. R. China.

Objectives: The NorA efflux pump in Staphylococcus aureus mediates resistance to many fluoroquinolone (FQ) antibiotics. Three norA alleles with high sequence similarity are found in various S. aureus strains exhibiting different FQ resistance profiles. This study aimed to elucidate the underlying molecular basis for the varying efflux activity of these three allelic variations.

Methods: The norA genotypes of 20 S. aureus isolates were analysed. Multiple alignments and conservative analyses were conducted to explore the evolutionary variations. After heterologous expression in Escherichia coli, seven mutants were constructed for MIC tests, efflux activity and conformational change measurements.

Results: Three NorA alleles were identified that displayed different FQ MICs and varying efflux activity for ethidium bromide, with the NorAII protein showing the strongest activity. A total of 29 single amino acid polymorphisms were identified by conservative analysis within three allelic peptides, with seven sites densely distributed in the 277-297 region. Mutations of these seven residues in NorAII all significantly impaired drug resistance and efflux activity, and three key mutants showed conformational changes in fluorescence resonance energy transfer (FRET) analysis.

Conclusions: Evolutionary variations of the 277-297 region could be a major explanation for the functional difference of three norA alleles and serve as a potential target for the development of novel NorA inhibitors.
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http://dx.doi.org/10.1093/jac/dkab066DOI Listing
March 2021

A Molecular Model of PEMFC Catalyst Layer: Simulation on Reactant Transport and Thermal Conduction.

Membranes (Basel) 2021 Feb 20;11(2). Epub 2021 Feb 20.

Moe Key Laboratory of Thermo-Fluid Science and Engineering, Energy and Power Engineering School, Xi'an Jiaotong University, Xi'an 710049, China.

Minimizing platinum (Pt) loading while reserving high reaction efficiency in the catalyst layer (CL) has been confirmed as one of the key issues in improving the performance and application of proton exchange membrane fuel cells (PEMFCs). To enhance the reaction efficiency of Pt catalyst in CL, the interfacial interactions in the three-phase interface, i.e., carbon, Pt, and ionomer should be first clarified. In this study, a molecular model containing carbon, Pt, and ionomer compositions is built and the radial distribution functions (RDFs), diffusion coefficient, water cluster morphology, and thermal conductivity are investigated after the equilibrium molecular dynamics (MD) and nonequilibrium MD simulations. The results indicate that increasing water content improves water aggregation and cluster interconnection, both of which benefit the transport of oxygen and proton in the CL. The growing amount of ionomer promotes proton transport but generates additional resistance to oxygen. Both the increase of water and ionomer improve the thermal conductivity of the C. The above-mentioned findings are expected to help design catalyst layers with optimized Pt content and enhanced reaction efficiency, and further improve the performance of PEMFCs.
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http://dx.doi.org/10.3390/membranes11020148DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7924188PMC
February 2021

Electrophysiological and Behavioral Responses of to Volatiles from Peanut.

Insects 2021 Feb 13;12(2). Epub 2021 Feb 13.

Institute of Life Science and Green Development, College of Life Science, Hebei University, Baoding 071002, China.

(Coleoptera: Scarabaeidae: Melolonthinae) is a notorious pest of many crops, especially peanuts. In this study, volatiles from peanut plants were analyzed using both gas chromatographic-electroantennographic detection (GC-EAD) and gas chromatography/mass spectrometry (GC/MS) techniques, and tested for adult attraction with field trapping bioassays in Hebei Province, China. GC-EAD analyses indicated that antennae strongly responded to twelve GC peaks, including eight identified compounds, ()--ocimene, hexanal, 6-methyl-5-hepten-2-one, nonanal, dihydromyrcenol, linalool, -caryophyllene, methyl salicylate, and four unidentified compounds. When tested individually in field conditions from 24 to 31 July, 2020, -caryophyllene and hexanal significantly attracted both sexes of , whereas all other compounds were unattractive. A blend of -caryophyllene and hexanal at a ratio of 2:1, close to the natural ratio of these two compounds from the intact peanut plant, was most attractive to the beetles. The remaining identified compounds, ()--ocimene, 6-methyl-5-hepten-2-one, nonanal, dihydromyrcenol, linalool, and methyl salicylate had no synergistic effects on attraction when tested in combination with the blend of -caryophyllene and hexanal. These results demonstrated that -caryophyllene and hexanal in the volatiles from peanut plants have strong attraction to . These two compounds have the potential to be used for monitoring and its management programs.
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http://dx.doi.org/10.3390/insects12020158DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7918631PMC
February 2021

Complete mitochondrial genome of (Lepidoptera: Noctuidae) from Egypt.

Mitochondrial DNA B Resour 2021 Feb 9;6(2):432-434. Epub 2021 Feb 9.

Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China.

The polyphagous cotton leafworm () is one of the most destructive herbivorous insects worldwide. The present study reports the complete mitochondrial genome of collected from Egypt. The circular-mapping mitogenome was 15,408 bp in length with an overall A + T content of 81.1%, encoding a common set of 37 genes, including 13 protein-coding genes (PCGs), 22 tRNA genes, and two rRNA genes. Most PCGs were found to use conventional ATN as the start codon and TAN as the stop codon. The phylogenetic tree based on the nucleic acid sequences of 13 shared PCGs of 29 Noctuidae species revealed that and are sister species. The data in this study will be helpful to understand geographical genetic variations, phylogenetic relationships, and species identification of .
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http://dx.doi.org/10.1080/23802359.2020.1870894DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7872533PMC
February 2021

Characterization of the mitochondrial genome of (Lepidoptera: Noctuidae) from South Africa.

Mitochondrial DNA B Resour 2021 Feb 8;6(2):370-372. Epub 2021 Feb 8.

Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China.

The African armyworm, , is an episodic migratory crop pest with an expanding distribution worldwide. This is the first report of the circular mitochondrial genome of , with a length of 15,457 bp and an A + T content of 81.7%. It encoded a common set of 37 genes, including 13 protein-coding genes (PCGs), 22 tRNA genes, and two rRNA genes, and contained a putative control region of 379 bp (94.7% in A + T proportion). The maximum-likelihood phylogenetic tree based on the complete mitogenome demonstrated that five species belonging to the genus formed one clade, in which was the most isolated branch, followed by . This data will contribute for the identification and phylogenetic analyses of , providing useful information for its comprehensive control.
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http://dx.doi.org/10.1080/23802359.2020.1869619DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7872540PMC
February 2021

Promoter engineering for high ectoine production in a lower saline medium by Halomonas hydrothermalis Y2.

Biotechnol Lett 2021 Apr 27;43(4):825-834. Epub 2021 Jan 27.

State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China.

Objectives: For the stress from fermenters, downstream processing equipment, and wastewater treatment to be alleviated, lowering salt-dependence in the ectoine synthesis process is of great significance in the moderately halotolerant Halomonas hydrothermalis Y2.

Results: In H. hydrothermalis Y2, the σ- and σ-controlled promoters of ectA are predicted to be involved in the osmotic regulation of ectoine synthesis. By substituting the ectA promoter with a promoter P that identified in the outer membrane pore protein E of H. hydrothermalis Y2, the salt dependence of ectoine synthesis was significantly decreased. In the 500-ml flask containing various NaCl contents, the engineered strain (p/Y2/△ectD/△doeA) showed a remarkably enhanced ability in ectoine synthesis, especially under lower saline stress. After a 36-h fed-batch fermentation in the 1-l fermenter, p/Y2/△ectD/△doeA synthesized 11.5 g ectoine l in the presence of 60 g NaCll, with a high 0.32 g ectoine l h productivity, a specific productivity of 512.2 mg ectoine per g cell dry weight (CDW), and an excretion ratio of 67 % ectoine.

Conclusions: As no impaired growth was observed in strain p/Y2/△ectD/△doeA while ectoine synthesis was increased, this promoter engineering strategy provides a practical protocol for lowering the salt-dependence of ectoine synthesis in this moderately halotolerant strain.
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http://dx.doi.org/10.1007/s10529-021-03084-3DOI Listing
April 2021

Novel electromagnetic-based navigation for percutaneous transforaminal endoscopic lumbar decompression in patients with lumbar spinal stenosis reduces radiation exposure and enhances surgical efficiency compared to fluoroscopy: a randomized controlled trial.

Ann Transl Med 2020 Oct;8(19):1215

Department of Orthopaedics, Xinqiao Hospital; Army Medical University, Chongqing, China.

Background: Percutaneous transforaminal endoscopic lumbar decompression (PTELD) is an emerging surgical alternative for treating lumbar spinal stenosis (LSS). However, the foraminoplasty procedure often requires repeated fluoroscopy, and endoscopy just offers a local view. No studies have focused on decreasing radiation exposure with electromagnetic navigation assistance. This study introduces a novel electromagnetic-based navigation (EMN) endoscopic system for PTELD in patients with LSS and compares the results in navigation and fluoroscopy groups.

Methods: Eighty-eight patients with LSS were randomized into either a navigation (44 patients) or fluoroscopy group. Duration of surgery, cannula placement time, radiation dose, blood loss, intraoperative pain assessment, and postoperative hospitalization stay were evaluated. The clinical outcomes were evaluated using a visual analogue scale (VAS), the Oswestry Disability Index (ODI), 6-minute walk test, and modified Macnab criteria.

Results: Eighty-five patients were followed-up for at least 12 months. The duration of surgery and cannula placement time were significantly more efficient in the navigation group (P=0.03 and P<0.001). Intraoperative pain assessment showed significantly less pain in the navigation group (P=0.038). The radiation dose was significantly higher in the fluoroscopy group than the navigation group (P<0.001). The VAS scores for back (P<0.001) and leg (P<0.001) pain improved significantly in both groups after surgery, as did the ODI (P<0.001) scores. Improvements in walking ability and Macnab criteria assessments at the 12-month follow-up, assessed subjective by patient assessments did not differ between the two groups.

Conclusions: The EMN system used in PTELD for patients with LSS compared to fluoroscopy enhances efficiency for foraminoplasty, reduces intraoperative pain and levels of radiation exposure. It results in outcomes comparable with results using fluoroscopy.
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http://dx.doi.org/10.21037/atm-20-1877DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7607128PMC
October 2020

RNA inter-nucleotide 3D closeness prediction by deep residual neural networks.

Bioinformatics 2020 Nov 2. Epub 2020 Nov 2.

School of Mathematical Sciences, Nankai University, Tianjin, 300071, China.

Motivation: Recent years have witnessed that the inter-residue contact/distance in proteins could be accurately predicted by deep neural networks, which significantly improve the accuracy of predicted protein structure models. In contrast, fewer studies have been done for the prediction of RNA inter-nucleotide 3 D closeness.

Results: We proposed a new algorithm named RNAcontact for the prediction of RNA inter-nucleotide 3 D closeness. RNAcontact was built based on the deep residual neural networks. The covariance information from multiple sequence alignments and the predicted secondary structure were used as the input features of the networks. Experiments show that RNAcontact achieves the respective precisions of 0.8 and 0.6 for the top L/10 and L (where L is the length of an RNA) predictions on an independent test set, significantly higher than other evolutionary coupling methods. Analysis shows that about 1/3 of the correctly predicted 3 D closeness are not base pairings of secondary structure, which are critical to the determination of RNA structure. In addition, we demonstrate that the predicted 3 D closeness could be used as distance restraints to guide RNA structure folding by the 3dRNA package. More accurate models could be built by using the predicted 3 D closeness than the models without using 3 D closeness.

Availability And Implementation: http://yanglab.nankai.edu.cn/RNAcontact/.

Contact: yangjy@nankai.edu.cn.

Supplementary Information: Supplementary data are available at Bioinformatics online.
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http://dx.doi.org/10.1093/bioinformatics/btaa932DOI Listing
November 2020

Two new species of the genus Sinodorcadion Gressitt, 1939 (Coleoptera: Cerambycidae: Lamiinae).

Zootaxa 2020 May 1;4768(2):zootaxa.4768.2.10. Epub 2020 May 1.

College of Agriculture, Yangtze University, Jingzhou, Hubei, 434025, P. R. China.

Two new species from China are described and illustrated, Sinodorcadion chinense Xie Wang sp. nov. from Hubei and Sinodorcadion zenghuaae Xie Wang sp. nov. from Guangxi. A key to species of the genus is presented.
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http://dx.doi.org/10.11646/zootaxa.4768.2.10DOI Listing
May 2020

A new species of Holangus Pic, 1902 (Coleoptera, Cerambycidae, Cerambycinae) from Hubei, China.

Zootaxa 2020 Sep 21;4853(1):zootaxa.4853.1.11. Epub 2020 Sep 21.

College of Agriculture, Yangtze University, Jingzhou, Hubei 434025, China.

Holangus shennongjiaensis sp. nov. from Shennongjia Forestry District, Hubei, China is described and illustrated.
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http://dx.doi.org/10.11646/zootaxa.4853.1.11DOI Listing
September 2020

Simultaneous quantification of nine components in the plasma of depressed rats after oral administration of Chaihu-Shugan-San by ultra-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry and its application to pharmacokinetic studies.

J Pharm Biomed Anal 2020 Jul 15;186:113310. Epub 2020 Apr 15.

State Key Laboratory Cultivation Base for TCM Quality and Efficacy, Institute of TCM-Related Comorbid Depression, Nanjing University of Chinese Medicine, Nanjing 210023, China. Electronic address:

Chaihu-Shugan-San (CSS), a classic Chinese formula, has long been used to treat depression. For a better and rational use of this formula, here, we investigated the comprehensive pharmacokinetic features of multiple ingredients from CSS using ultra-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (UPLC-QTOF-MS) in depressed rats. Force swimming experiments were conducted to establish a rat model of depression. Prolonged immobility time, increased plasma adrenocorticotropic hormone, and decreased plasma 5-hydroxytryptamine (5-HT) and dopamine (DA) were confirmed in this model. Nine compounds from CSS, including ferulic acid, naringin, hesperidin, meranzin hydrate, glycyrrhizic acid, saikosaponin A, nobiletin, and hesperetin, were simultaneously determined in plasma samples. Sulfamethoxazole and schisandrin were used as internal standards. The separation was performed on a C column with gradient elution over 10 min, and detection was executed using multiple reaction monitoring (MRM) in the positive ionization mode. The optimized MRM transitions showed no interference in rat plasma. Validation parameters were all in accordance with the current criterion. The established method was successfully applied to the pharmacokinetic study of these nine components after the oral administration of CSS to depressed rats. This study provides a chemical basis for the clinical application of this formula.
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http://dx.doi.org/10.1016/j.jpba.2020.113310DOI Listing
July 2020

A new species of genus Falsoibidion Pic, 1922 (Coleoptera: Cerambycidae: Cerambycinae) from Hubei, China.

Zootaxa 2020 Feb 20;4742(2):zootaxa.4742.2.12. Epub 2020 Feb 20.

College of Agriculture, Yangtze University, Jingzhou, Hubei 434025, China.

The genus Falsoibidion Pic, 1922 (Cerambycidae: Cerambyinae: Callidiopini) was established based on an Oriental species Falsoibidion fasciatum Pic, 1922 from Vietnam.
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http://dx.doi.org/10.11646/zootaxa.4742.2.12DOI Listing
February 2020

Advances in the Masquelet technique: Myeloid-derived suppressor cells promote angiogenesis in PMMA-induced membranes.

Acta Biomater 2020 05 9;108:223-236. Epub 2020 Mar 9.

Department of Orthopaedics, Xinqiao Hospital, Amy Medical University (Third Military Medical University), Chongqing, PR China. Electronic address:

The periosteum plays a critical role in bone formation and defect reconstruction. The concept of tissue engineering in the periosteum has been suggested to solve the clinical problems related to bone defect repair. Insertion of polymethyl methacrylate (PMMA) bone cement can induce the autologous generation of a tissue-engineered periosteum and has been considered as a promising strategy for bone defect reconstruction. The PMMA-induced membrane is a crucial element in the reconstruction of bone defects, especially for angiogenesis, but its biological mechanism remains elusive. Here, a PMMA-induced membrane model was established using a femoral critically sized defect in mice. We identified myeloid-derived suppressor cells (MDSCs) as a regulatory component of induced membrane vascularization. The increased number of MDSCs was markedly linked to increased membrane thickness and capillary density. Importantly, the results of an in vitro coculture assay indicated that MDSCs of the induced membrane further facilitated the angiogenic capacity of human umbilical vein endothelial cells (HUVECs) by upregulating the expression of VEGFA, Ang2 and HIF-1α. Furthermore, signaling pathway blockade results suggested that STAT3 activation is involved in the upregulation of VEGFA, Ang2 and HIF-1α expression in induced membrane MDSCs. Our findings provide new insights into the mechanism of angiogenesis in the PMMA-induced membrane and confirm the key signaling molecules of MDSCs in induced membrane angiogenesis. Based on these results, this strategy may become a new therapy for the treatment of large bone defects in the future. STATEMENT OF SIGNIFICANCE: In this study, we established an autologous tissue-engineered periosteum - PMMA-induced membrane, which was formed by the foreign body reaction to PMMA bone cement. The induced membrane establishes a blood supply for the large bone defect healing. After investigation, our study discovered the critical cell type in the formation and angiogenesis processes of the induced membrane, myeloid-derived suppressor cells (MDSCs). We revealed that MDSCs of the induced membrane promote the angiogenesis of endothelial cells through the expression of VEGFA, Ang2 and HIF-1α, which was upregulated by the activation of STAT3 signaling. Our findings clarified the beneficial effect of MDSCs in the angiogenesis of bone repair, and offered an additional target for the study of foreign body reactions to bone repair materials.
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http://dx.doi.org/10.1016/j.actbio.2020.03.010DOI Listing
May 2020

Correction to: BM-MSC-derived exosomes alleviate radiation-induced bone loss by restoring the function of recipient BM-MSCs and activating Wnt/β-catenin signaling.

Stem Cell Res Ther 2020 Jan 23;11(1):33. Epub 2020 Jan 23.

Department of Orthopedics, Xinqiao Hospital, Army Medical University (Third Military Medical University), Chongqing, 400038, People's Republic of China.

The original article [1] contains an error in Fig. 5 whereby sub-Fig. 5c, d & 5e are mistakenly mixed-up.
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http://dx.doi.org/10.1186/s13287-020-1553-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6979329PMC
January 2020

Percutaneous placement of lumbar pedicle screws via intraoperative CT image-based augmented reality-guided technology.

J Neurosurg Spine 2019 Dec 20:1-6. Epub 2019 Dec 20.

Objective: The authors aimed to assess, in a bone-agar experimental setting, the feasibility and accuracy of percutaneous lumbar pedicle screw placements using an intraoperative CT image-based augmented reality (AR)-guided method compared to placements using a radiograph-guided method. They also compared two AR hologram alignment methods.

Methods: Twelve lumbar spine sawbones were completely embedded in hardened opaque agar, and a cubic marker was fixed on each phantom. After intraoperative CT, a 3D model of each phantom was generated, and a specialized application was deployed into an AR headset (Microsoft HoloLens). One hundred twenty pedicle screws, simulated by Kirschner wires (K-wires), were placed by two experienced surgeons, who each placed a total of 60 screws: 20 placed with a radiograph-guided technique, 20 with an AR technique in which the hologram was manually aligned, and 20 with an AR technique in which the hologram was automatically aligned. For each K-wire, the insertion path was expanded to a 6.5-mm diameter to simulate a lumbar pedicle screw. CT imaging of each phantom was performed after all K-wire placements, and the operative time required for each K-wire placement was recorded. An independent radiologist rated all images of K-wire placements. Outcomes were classified as grade I (no pedicle perforation), grade II (screw perforation of the cortex by up to 2 mm), or grade III (screw perforation of the cortex by > 2 mm). In a clinical situation, placements scored as grade I or II would be acceptable and safe for patients.

Results: Among all screw placements, 75 (94%) of 80 AR-guided placements and 40 (100%) of 40 radiograph-guided placements were acceptable (i.e., grade I or II; p = 0.106). Radiograph-guided placements had more grade I outcomes than the AR-guided method (p < 0.0001). The accuracy of the two AR alignment methods (p = 0.526) was not statistically significantly different, and neither was it different between the AR and radiograph groups (p < 0.0001). AR-guided placements required less time than the radiograph-guided placements (mean ± standard deviation, 131.76 ± 24.57 vs 181.43 ± 15.82 seconds, p < 0.0001). Placements performed using the automatic-alignment method required less time than those using the manual-alignment method (124.20 ± 23.80 vs 139.33 ± 23.21 seconds, p = 0.0081).

Conclusions: In bone-agar experimental settings, AR-guided percutaneous lumbar pedicle screw placements were acceptable and more efficient than radiograph-guided placements. In a comparison of the two AR-guided placements, the automatic-alignment method was as accurate as the manual method but more efficient. Because of some limitations, the AR-guided system cannot be recommended in a clinical setting until there is significant improvement of this technology.
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http://dx.doi.org/10.3171/2019.10.SPINE19969DOI Listing
December 2019

A new species of the genus Eucyclodes (Lepidoptera, Geometridae, Geometrinae) from China.

Zootaxa 2019 Oct 31;4691(3):zootaxa.4691.3.11. Epub 2019 Oct 31.

Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China School of Agriculture, Yangtze University, Hubei, China.

The genus Eucyclodes was originally established by Warren (1894) on the basis of Phorodesma buprestaria Guenée, 1858. Eucyclodes is a large genus, which contains more than 90 species (Scoble 1999; Scoble Hausmann 2007), mainly distributed in the Indo-Australian tropics, and more than 50% of all species are found in New Guinea. More than 90% of all Eucyclodes species were described before the 1950s. The most recent additions were made by Inoue (1978, 1986), Holloway Sommerer (1984), Holloway (1996), and Tautel (2016), who each erected one new species per publication. The tribal position of Eucyclodes is still uncertain, for example, Pitkin (1996), Holloway (1996) and Ban et al. (2018) placed it in the tribe Nemoriini (or Nemoriiti), and the most recent research by Murillo-Ramos et al. (2019) found that Eucyclodes is sister to other Nemoriini and the authors did not assign it to any tribe.
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http://dx.doi.org/10.11646/zootaxa.4691.3.11DOI Listing
October 2019

A new species of Pseudoechthistatus Pic, 1917 (Coleoptera, Cerambycidae, Lamiinae) from Yunnan, China.

Zootaxa 2019 Jun 18;4619(1):zootaxa.4619.1.10. Epub 2019 Jun 18.

Hubei Collaborative Innovation Center for Grain Industry, Jingzhou, Hubei 434025, China College of Agriculture, Yangtze University, Jingzhou, Hubei 434025, China.

Pseudoechthistatus hei Xie W. Wang sp. nov. from Yunnan, China is described and illustrated.
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http://dx.doi.org/10.11646/zootaxa.4619.1.10DOI Listing
June 2019

Synthesis and bioactivity of indoleacetic acid-carbendazim and its effects on Cylindrocladium parasiticum.

Pestic Biochem Physiol 2019 Jul 11;158:128-134. Epub 2019 May 11.

College of Agriculture, Yangtze University, Jingzhou 434025, PR China. Electronic address:

Indoleacetic acid (IAA)-carbendazim was synthesized to assess whether this conjugate could retain the fungicidal activity of carbendazim and gain root-inducing properties upon the addition of an indoleacetic acid group. An indoor virulence test demonstrated that the conjugate retained the fungicidal activity of carbendazim towards Cylindrocladium parasiticum. The conjugate was detected in roots after soaking Ricinus communis L. leaves into a solution of the IAA-carbendazim, which confirmed its phloem mobility. The activities of the cellulase, polygalacturonase and xylanase produced by Cylindrocladium parasiticum treated with different concentrations of the conjugate were determined, and the peak activities appeared at 72 h or 96 h. More importantly, the conjugate showed the ability to promote root growth. These results revealed that indoleacetic acid-carbendazim may be useful in preventing Cylindrocladium parasiticum and other diseases.
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http://dx.doi.org/10.1016/j.pestbp.2019.05.001DOI Listing
July 2019

Comparison of the fenestrated pedicle screw and conventional pedicle screw in minimally percutaneous fixation for the treatment of spondylolisthesis with osteoporotic spine.

Clin Neurol Neurosurg 2019 Aug 23;183:105377. Epub 2019 May 23.

Department of Orthopaedics, Xinqiao Hospital, Amy Military University(Third Military Medical University), Chongqing, 400037, China. Electronic address:

Objectives: To assess the feasibility of cement-augmented fenestrated pedicle screw for patients with spondylolisthesis with osteoporotic spine.

Patients And Methods: From January 2014 to March 2018, a retrospective study of 88 patients with spondylolisthesis and osteoporosis treated with minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) using the conventional pedicle screw (CPS group, n = 52) and the fenestrated pedicle screw (FPS group, n = 36) was performed with a follow-up of 30 months (range, 10-58 months). Clinical outcomes, overall changes in slip degree, and interbody fusion rates were evaluated via questionnaires and radiographic parameters.

Results: The VAS, ODI and JOA scores at 3 months were significantly improved in both groups compared with the preoperative assessment (p < 0.001). No significant differences in scores were found between the two groups at any time. Imaging results at different time points revealed greater postoperative improvement in the Taillard index in the FPS group compared with the CPS group. No significant differences in the interbody fusion speed or rates were found between the two groups. In the FPS group, cement leakage occurred in 22 of 97 screws (22.7%), and symptomatic cement leakage was not found.

Conclusion: MIS-TLIF combined with fenestrated pedicle screws provided greater reduction than did MIS-TLIF combined with conventional pedicle screws in terms of postoperative slip degree. And the application of fenestrated pedicle screw did not obstruct the interbody fusion. Overall, MIS-TLIF combined with the fenestrated pedicle screws is an effective and safe technique for the treatment of spondylolisthesis with osteoporotic spine.
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http://dx.doi.org/10.1016/j.clineuro.2019.105377DOI Listing
August 2019

Using green emitting pH-responsive nanogels to report environmental changes within hydrogels: a nanoprobe for versatile sensing.

Nanoscale 2019 Jun;11(24):11484-11495

School of Materials, University of Manchester, MSS Tower, Manchester, M13 9PL, UK.

Remotely reporting the local environment within hydrogels using inexpensive laboratory techniques has excellent potential to improve our understanding of the nanometer-scale changes that cause macroscopic swelling or deswelling. Whilst photoluminescence (PL) spectroscopy is a popular method for such studies this approach commonly requires bespoke and time-consuming synthesis to attach fluorophores which may leave toxic residues. A promising and more versatile alternative is to use a pre-formed nanogel probe that contains a donor/acceptor pair and then "dope" that into the gel during gel assembly. Here, we introduce green-emitting methacrylic acid-based nanogel probe particles and use them to report the local environment within four different gels as well as stem cells. As the swelling of the nanogel probe changes within the gels the non-radiative energy transfer efficiency is strongly altered. This efficiency change is sensitively reported using the PL ratiometric intensity from the donor and acceptor. We demonstrate that our new nanoprobes can reversibly report gel swelling changes due to five different environmental stimuli. The latter are divalent cations, gel degradation, pH changes, temperature changes and tensile strain. In the latter case, the nanoprobe rendered a nanocomposite gel mechanochromic. The results not only provide new structural insights for hierarchical natural and synthetic gels, but also demonstrate that our new green-fluorescing nanoprobes provide a viable alternative to custom fluorophore labelling for reporting the internal gel environment and its changes.
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http://dx.doi.org/10.1039/c9nr00989bDOI Listing
June 2019

Rapamycin Induced Autophagy Inhibits Inflammation-Mediated Endplate Degeneration by Enhancing Nrf2/Keap1 Signaling of Cartilage Endplate Stem Cells.

Stem Cells 2019 06 26;37(6):828-840. Epub 2019 Mar 26.

Department of Orthopedics, Xinqiao Hospital, Army Military Medical University, Chongqing, People's Republic of China.

Cartilage endplate (CEP) calcification inhibits the transport of metabolites and nutrients in the intervertebral disk and is an important initiating factor of intervertebral disk degeneration. However, the mechanisms governing CEP degeneration have not been thoroughly elucidated. In this study, we established a mouse CEP degeneration model and showed that autophagy insufficiency caused the degeneration of CEP. We found that the inflammatory cytokine tumor necrosis factor-α (TNF-α) increased the level of intracellular reactive oxygen species (ROS) and caused cell senescence and osteogenic differentiation of cartilage endplate stem cells (CESCs), whereas rapamycin-induced autophagy protected CESCs from TNF-α-induced oxidative stress and cell senescence. Furthermore, rapamycin-induced autophagy helped CESCs maintain the chondrogenic properties and inhibited extracellular matrix protease expression and osteogenic differentiation. Further study revealed that autophagy activated by rapamycin or inhibited by chloroquine influenced the expression and nuclear translocation of Nrf2, thereby controlling the expression of antioxidant proteins and the scavenging of ROS. Taken together, the results indicate that rapamycin-induced autophagy enhances Nrf2/Keap1 signaling and promotes the expression of antioxidant proteins, thereby eliminating ROS, alleviating cell senescence, reducing the osteogenic differentiation of CESCs, and ultimately protecting CEPs from chronic inflammation-induced degeneration. Stem Cells 2019;37:828-840.
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http://dx.doi.org/10.1002/stem.2999DOI Listing
June 2019

BM-MSC-derived exosomes alleviate radiation-induced bone loss by restoring the function of recipient BM-MSCs and activating Wnt/β-catenin signaling.

Stem Cell Res Ther 2019 01 15;10(1):30. Epub 2019 Jan 15.

Department of Orthopedics, Xinqiao Hospital, Army Medical University (Third Military Medical University), Chongqing, 400038, People's Republic of China.

Background: Radiotherapy to cancer patients is inevitably accompanied by normal tissue injury, and the bone is one of the most commonly damaged tissues. Damage to bone marrow mesenchymal stem cells (BM-MSCs) induced by radiation is thought to be a major cause of radiation-induced bone loss. Exosomes exhibit great therapeutic potential in the treatment of osteoporosis, but whether exosomes are involved in radiation-induced bone loss has not been thoroughly elucidated to date. The main purpose of this study is to investigate the role of exosomes derived from BM-MSCs in restoring recipient BM-MSC function and alleviating radiation-induced bone loss.

Methods: BM-MSC-derived exosomes were intravenously injected to rats immediately after irradiation. After 28 days, the left tibiae were harvested for micro-CT and histomorphometric analysis. The effects of exosomes on antioxidant capacity, DNA damage repair, proliferation, and cell senescence of recipient BM-MSCs were determined. Osteogenic and adipogenic differentiation assays were used to detect the effects of exosomes on the differentiation potential of recipient BM-MSCs, and related genes were measured by qRT-PCR and Western blot analysis. β-Catenin expression was detected at histological and cytological levels.

Results: BM-MSC-derived exosomes can attenuate radiation-induced bone loss in a rat model that is similar to mesenchymal stem cell transplantation. Exosome-treated BM-MSCs exhibit reduced oxidative stress, accelerated DNA damage repair, and reduced proliferation inhibition and cell senescence-associate protein expression compared with BM-MSCs that exclusively received irradiation. Following irradiation, exosomes promote β-catenin expression in BM-MSCs and restore the balance between adipogenic and osteogenic differentiation.

Conclusions: Our findings indicate that BM-MSC-derived exosomes take effects by restoring the function of recipient BM-MSCs. Therefore, exosomes may represent a promising cell-free therapeutic approach for the treatment of radiation-induced bone loss.
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http://dx.doi.org/10.1186/s13287-018-1121-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6334443PMC
January 2019

Biomechanical Stability Before and After Graft Fusion with Unilateral and Bilateral Pedicle Screw Fixation: Finite Element Study.

World Neurosurg 2019 Mar 24;123:e228-e234. Epub 2018 Nov 24.

Department of Orthopaedics, Xinqiao Hospital, Army Military University, Chongqing, People's Republic of China. Electronic address:

Background: Minimally invasive transformational lumbar interbody fusion (MI-TLIF) with unilateral pedicle screw (UPS) fixation was controversial. The aim of this study was to compare the stability between UPS and bilateral pedicle screw (BPS) fixation before and after graft fusion.

Methods: An L3-L5 finite element model was modified to simulate L4/5 MI-TLIF. Five different statuses of posterior instrumentation were simulated: UPS fixation or BPS fixation before and after graft fusion and removal of posterior instrumentation after graft fusion. Range of motion and Von Mises stress were evaluated for intact and instrumentation models in all loading planes.

Results: Range of motion of the L4/5 segment with UPS fixation was 2.1, 1.3, and 1.7 times greater than those with BPS fixation before fusion in flexion-extension, lateral bending, and axial rotation, respectively, while it was 1.3, 1.1, and 1.4 times greater after fusion. The peak Von Mises stresses on posterior instrumentations with UPS fixation ranged from 1.0 to 1.7 times greater than those in BPS fixation before fusion, while it ranged from 1.0 to 1.4 times greater after fusion. The peak Von Mises stresses on intervertebral graft with UPS fixation ranged from 1.9 to 3.5 times greater than those with BPS fixation before fusion, while it ranged from 0.9 to 1.2 times greater after fusion.

Conclusions: Fusion of graft improved the fixation effect of posterior instrumentation system. Unilateral pedicle screw fixation could provide similar biomechanical stability to bilateral pedicle screw fixation in 1-level MI-TLIF after fusion.
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http://dx.doi.org/10.1016/j.wneu.2018.11.141DOI Listing
March 2019

Do the properties of gels constructed by interlinking triply-responsive microgels follow from those of the building blocks?

Soft Matter 2019 Jan 16;15(4):527-536. Epub 2018 Nov 16.

Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.

Microgels (MGs) are swellable crosslinked polymer colloids. They can also be used as the only building block to construct nanostructured hydrogels which are denoted as doubly crosslinked microgels (DX MGs). Here, new triply responsive DX MGs comprised of interlinked MGs of oligo(ethylene glycol)methacrylate (OEGMA), 2-(2-methoxyethoxy)ethyl methacrylate (MEOMA), methacrylic acid (MAA) and a o-nitrobenzyl-based UV photocleavable crosslinker are investigated. The MGs swelled or collapsed in response to temperature and pH changes. These behaviours were rationalised with a generic model using Monte Carlo simulations. The MGs also degraded when UV irradiated due to photocleavage of nPh. DX MGs were assembled from the MGs to give injectable gels that were not cytotoxic to nucleus pulposus cells. Comparison of the responsive properties of the DX MGs and MGs showed that the temperature and pH responses of the former were mostly governed by the latter. However, two key differences were found. Firstly, whilst increasing the crosslinker mol% in the MG building blocks (x) did not change MG particle swelling, the compression modulus (E) and swelling of the DX MG gels were strongly affected by x. The E value for the gels was tuneable using x which is a potentially useful new observation for DX MGs. Secondly, UV irradiation of the DX MGs enhanced gel mechanical photostability in contrast to the behaviour of the MGs. We find that the properties of the DX MGs do not simply follow those of the parent MGs and propose mechanisms to account for the differences. The new family of multi-responsive DX MGs presented in this study have potential application for soft tissue repair as injectable gels or as gel implants which report sterilisation.
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http://dx.doi.org/10.1039/c8sm01510dDOI Listing
January 2019

Highly deformable hydrogels constructed by pH-triggered polyacid nanoparticle disassembly in aqueous dispersions.

Soft Matter 2018 May;14(18):3510-3520

School of Materials, University of Manchester, MSS Tower, Manchester, M13 9PL, UK.

Most hydrogels are prepared using small-molecule monomers but unfortunately this approach may not be feasible for certain biomaterial applications. Consequently, alternative gel construction strategies have been established, which include using covalent inter-linking of preformed gel particles, or microgels (MGs). For example, covalently interlinking pH-responsive MGs can produce hydrogels comprising doubly crosslinked microgels (DX MGs). We hypothesised that the deformability of such DX MGs was limited by the presence of intra-MG crosslinking. Thus, in this study we designed new nanoparticle (NP)-based gels based on pH-swellable NPs that are not internally crosslinked. Two polyacid NPs were synthesised containing methacrylic acid (MAA) and either ethyl acrylate (EA) or methyl methacrylate (MMA). The PMAA-EA and PMAA-MMA NPs were subsequently vinyl-functionalised using glycidyl methacrylate (GMA) prior to gel formation via free-radical crosslinking. The NPs mostly disassembled on raising the solution pH but some self-crosslinking was nevertheless evident. The gels constructed from the EA- and MMA-based NPs had greater breaking strains than a control DX MG. The effect of varying the solution pH during curing on the morphology and mechanical properties of gels prepared using PMAA-MMA-GMA NPs was studied and both remarkable deformability and excellent recovery were observed. The gels were strongly pH-responsive and had tensile breaking strains of up to 420% with a compressive strain-at-break of more than 93%. An optimised formulation produced the most deformable and stretchable gel yet constructed using NPs or MGs as the only building block.
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http://dx.doi.org/10.1039/c8sm00325dDOI Listing
May 2018

Pickering Emulsions Stabilized by pH-Responsive Microgels and Their Scalable Transformation to Robust Submicrometer Colloidoisomes with Selective Permeability.

Langmuir 2017 08 8;33(33):8192-8200. Epub 2017 Aug 8.

Polymers and Composites Group, School of Materials, The University of Manchester , MSS Tower, Manchester M13 9PL, U.K.

Colloidosomes are micrometer-sized hollow particles that have shells consisting of coagulated or fused colloid particles. While many large colloidosomes with sizes well above 1.0 μm have been prepared, there are fewer examples of submicrometer colloidosomes. Here, we establish a simple emulsion templating-based method for the preparation of robust submicrometer pH-responsive microgel colloidosomes. The colloidosomes are constructed from microgel particles based on ethyl acrylate and methacrylic acid with peripheral vinyl groups. The pH-responsive microgels acted as both a Pickering emulsion stabilizer and macro-cross-linker. The emulsion formation studies showed that the minimum droplet diameter was reached when the microgel particles were partially swollen. Microgel colloidosomes were prepared by covalently interlinking the microgels adsorbed at the oil-water interface using thermal free-radical coupling. The colloidosomes were prepared using a standard high-shear mixer with two different rotor sizes that corresponded to high shear (HS) and very high shear (VHS) mixing conditions. The latter enabled the construction of submicrometer pH-responsive microgel-colloidosomes on the gram scale. The colloidosomes swelled strongly when the pH increased to above 6.0. The colloidosomes were robust and showed no evidence of colloidosome breakup at high pH. The effect of solute size on shell permeation was studied using a range of FITC-dextran polymers, and size-selective permeation occurred. The average pore size of the VHS microgel-colloidosomes was estimated to be between 6.6 and 9.0 nm at pH 6.2. The microgel-colloidosome properties suggest that they have the potential for future applications in cosmetics, photonics, and delivery.
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http://dx.doi.org/10.1021/acs.langmuir.7b01618DOI Listing
August 2017

A new species of the genus Pseudotrachystola Breuning (Coleoptera: Cerambycidae: Lamiinae) from China.

Zootaxa 2016 Oct 28;4179(1):118-122. Epub 2016 Oct 28.

Institute of Entomology, Yangtze University, Jingzhou, Hubei, 434025, P. R. China Graduate School, Yangtze University, Jingzhou, Hubei, 434025, P. R. China; Email: unknown.

The second species of Pseudotrachystola Breuning, P. yei, sp. nov., is described and illustrated from Hubei, China. The holotype is deposited in the Entomological Museum of Yangtze University. The Chinese name of the new species is designated as .
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http://dx.doi.org/10.11646/zootaxa.4179.1.8DOI Listing
October 2016

Using intra-microgel crosslinking to control the mechanical properties of doubly crosslinked microgels.

Soft Matter 2016 Aug;12(33):6985-94

School of Materials, The University of Manchester, MSS Tower, Manchester, M13 9PL, UK.

Microgels (MGs) are crosslinked polymer particles that swell when the pH approaches the pKa of the constituent polymer. Our earlier work showed that concentrated MG dispersions can be covalently interlinked to form macroscopic hydrogels, which are termed doubly crosslinked microgels (DX MGs). Here, we study for the first time the effects of intra-MG crosslinking on the swelling of the MGs and the mechanical properties of the DX MGs. The MGs were synthesised by emulsion copolymerisation of ethyl acrylate (EA) or methacrylic acid (MAA) and divinylbenzene (DVB). The latter was a crosslinking monomer. For comparison, MGs were prepared where DVB was replaced by either 1,4-butanediol diacrylate (BDDA) or a 1 : 1 mixture of both DVB and BDDA. The MG swelling behaviours were studied by dynamic light scattering; whereas, the DX MG mechanical properties were studied by dynamic rheology and uniaxial compression measurements. Inclusion of DVB within the MGs resulted in both highly swelling MGs and highly ductile DX MGs. The average strain-at-break value for the DVB-containing DX MGs was 76% which represents the highest value yet reported for a DX MG prepared using commercially available monomers. It was also shown that good tuneability of the DX MG properties could be obtained simply by controlling the DVB and BDDA contents within the MG particles. Analysis of the swelling and compression data enabled relationships between the volume-swelling ratio of the MGs and either the modulus or strain-at-break values for the DX MGs. These relationships also applied to a DVB-free system prepared with a low BDDA content. An interesting conclusion from this study is that the DX MGs can be thought of mechanically as macroscopic MG particles. The results of this study provide design tools for improving DX MG ductility and hence increasing the range of potential applications for this new class of hydrogel.
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http://dx.doi.org/10.1039/c6sm01337fDOI Listing
August 2016

A study of conductive hydrogel composites of pH-responsive microgels and carbon nanotubes.

Soft Matter 2016 05 12;12(18):4142-53. Epub 2016 Apr 12.

School of Materials, The University of Manchester, MSS Tower, Manchester, M13 9PL, UK.

Conductive gel composites are attracting considerable attention because of their interesting electrical and mechanical properties. Here, we report conductive gel composites constructed using only colloidal particles as building blocks. The composites were prepared from mixed dispersions of vinyl-functionalised pH-responsive microgel particles (MGs) and multi-walled carbon nanotubes (CNTs). MGs are crosslinked pH-responsive polymer colloid particles that swell when the pH approaches the pKa of the particles. Two MG systems were used which contained ethyl acrylate (EA) or methyl acrylate (MA) and around 30 mol% of methacrylic acid (MAA). The MA-based MG is a new pH-responsive system. The mixed MG/CNT dispersions formed thixotropic physical gels. Those gels were transformed into covalent interlinked electrically conducting doubly crosslinked microgel/CNT composites (DX MG/CNT) by free-radical reaction. The MGs provided the dual roles of dispersant for the CNTs and macro-crosslinker for the composite. TEM data showed evidence for strong attraction between the MG and the CNTs which facilitated CNT dispersion. An SEM study confirmed CNT dispersion throughout the composites. The mechanical properties of the composites were studied using dynamic rheology and uniaxial compression measurements. Surprisingly, both the ductility and the modulus of the gel composites increased with increasing CNT concentration used for their preparation. Human adipose-derived mesenchymal stem cells (AD-MSCs) exposed to DX MG/CNT maintained over 99% viability with metabolic activity retained over 7 days, which indicated non-cytotoxicity. The results of this study suggest that our approach could be used to prepare other DX MG/CNT gel composites and that these materials may lead to future injectable gels for advanced soft-tissue repair.
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http://dx.doi.org/10.1039/c6sm00223dDOI Listing
May 2016