490 results on '"Xu, Wenqiang"'
Search Results
452. Abnormal Functional Connectivity Within Default Mode Network and Salience Network Related to Tinnitus Severity.
- Author
-
Xiong B, Liu Z, Li J, Huang X, Yang J, Xu W, Chen YC, Cai Y, and Zheng Y
- Subjects
- Humans, Default Mode Network, Brain, Gyrus Cinguli, Magnetic Resonance Imaging, Brain Mapping, Tinnitus
- Abstract
Background: Previous studies have demonstrated that tinnitus is associated with neural changes in the cerebral cortex. This study is aimed at investigating the central nervous characteristics of tinnitus patients with different severity by using a rs-EEG., Participants and Methods: rs-EEG was recorded in fifty-seven patients with chronic tinnitus and twenty-seven healthy controls. Tinnitus patients were divided into moderate-to-severe tinnitus group and slight-to-mild tinnitus group based on their Tinnitus Handicap Inventory (THI) scores. Source localization and functional connectivity analyses were used to measure the changes in central levels and examine the altered network patterns. The correlation between functional connectivity and tinnitus severity was analyzed., Result: Compared to the healthy controls, all tinnitus patients showed significant activation in the auditory cortex (middle temporal lobe, BA 21), while moderate-to-severe tinnitus group showed enhanced connectivity between the parahippocampus and posterior cingulate gyrus. Moreover, the moderate-to-severe tinnitus group had enhanced functional connectivity between auditory cortex and insula compared to the slight-to-mild tinnitus group. The connections between the insula and the parahippocampal and posterior cingulate gyrus were positively correlated with THI scores., Conclusion: The current study reveals that patients with moderate-to-severe tinnitus demonstrate greater changes in the central brain areas, including the auditory cortex, insula, parahippocampus and posterior cingulate gyrus. In addition, enhanced connections were found between the insula and the auditory cortex, as well as the posterior cingulate gyrus and the parahippocampus, which suggests abnormality in the auditory network, salience network, and default mode network. Specifically, the insula is the core region of the neural pathway that is composed of the auditory cortex, insula, and parahippocampus/posterior cingulate gyrus. This suggests that the severity of tinnitus is affected by multiple brain regions., (© 2023. The Author(s) under exclusive licence to Association for Research in Otolaryngology.)
- Published
- 2023
- Full Text
- View/download PDF
453. Enzymatic Characterization of the Isocitrate Dehydrogenase with Dual Coenzyme Specificity from the Marine Bacterium Umbonibacter marinipuiceus .
- Author
-
Bian M, Zhao J, Xu W, Han X, Chen X, Wang P, and Zhu G
- Subjects
- NADP metabolism, Isocitrate Dehydrogenase metabolism, Amino Acid Sequence, Kinetics, Coenzymes metabolism, NAD metabolism
- Abstract
Isocitrate dehydrogenase (IDH) can be divided into NAD
+ -dependent and NADP+ -dependent types based on the coenzyme specificity. It is worth noting that some IDHs exhibit dual coenzyme specificity characteristics. Herein, a dual coenzyme-dependent IDH from Umbonibacter Marinipuiceus (UmIDH) was expressed, purified, and identified in detail for the first time. SDS-PAGE and Gel filtration chromatography analyses showed that UmIDH is an 84.7 kDa homodimer in solution. The Km values for NAD+ and NADP+ are 1800.0 ± 64.4 μM and 1167.7 ± 113.0 μM in the presence of Mn2+ , respectively. Meanwhile, the catalytic efficiency ( kcat / Km ) of UmIDH is only 2.3-fold greater for NADP+ than NAD+ . The maximal activity for UmIDH occurred at pH 8.5 (with Mn2+ ) or pH 8.7 (with Mg2+ ) and at 35 °C (with Mn2+ or Mg2+ ). Heat inactivation assay revealed that UmIDH sustained 50% of maximal activity after incubation at 57 °C for 20 min with either Mn2+ or Mg2+ . Moreover, three putative core coenzyme binding residues (R345, L346, and V352) of UmIDH were evaluated by site-directed mutagenesis. This recent work identified a unique dual coenzyme-dependent IDH and achieved the groundbreaking bidirectional modification of this specific IDH's coenzyme dependence for the first time. This provides not only a reference for the study of dual coenzyme-dependent IDH, but also a basis for the investigation of the coenzyme-specific evolutionary mechanisms of IDH.- Published
- 2023
- Full Text
- View/download PDF
454. Controlled Isotropic Canalization of Microsized Silicon Enabling Stable High-Rate and High-Loading Lithium Storage.
- Author
-
Wang D, Ma Y, Xu W, Zhang S, Wang B, Zhi L, and Li X
- Abstract
Silicon is attractive for lithium-ion batteries and beyond but suffers large volume change upon cycling. Hierarchical tactics show promise yet lack control over the unit construction and arrangement, limiting stability improvement at the practical level. Here, a protocol is developed as controlled isotropic canalization of microsized silicon. Distinct from the existing strategies, it involves isotropic canalization by honeycomb-like radial arrangement of silicon nanosheets, and canal consolidation by controlled dual bonding of silicon with carbon. The proof-of-concept nitrogen-doped carbon dual-bonded silicon honeycomb-like microparticles, specifically with a medium density of CNSi and COSi bonds, exhibit stable cycling impressively at high rates and industrial-scale loadings. Two key issues involve isotropic canalization facilitating ion transport in all directions of individual granules and controlled consolidation conferring selective ion permeation and securing charge transport. The study highlights the configurational isotropy and interfacial bonding density, and provides insight into rational design and manufacture of silicon and others with industry-viable features., (© 2023 Wiley-VCH GmbH.)
- Published
- 2023
- Full Text
- View/download PDF
455. Inverse Electron-Demanding Diels-Alder Reactions in the Chemical Synthesis of Prenylated Indole Alkaloids Containing a Bicycle[2.2.2]diazaoctane Moiety: A Theoretical Study.
- Author
-
Xu W, Sun TY, Di Y, Hao X, and Wu YD
- Abstract
The Diels-Alder reaction is believed to be a key step in the biosynthesis of prenylated indole alkaloids containing a bicycle[2.2.2]diazaoctane moiety. Many chemical syntheses of bicyclic structures by Diels-Alder reactions have been reported, but the reaction mechanism remains underexplored. We have carried out DFT calculations on both acid- and base-promoted Diels-Alder reactions in these syntheses and reveal that the reactions occur through an inverse-electron demand mechanism. We hope that the new mechanism is helpful for the mechanistic understanding of the biosynthesis of this class of important natural products., (© 2023 Wiley-VCH GmbH.)
- Published
- 2023
- Full Text
- View/download PDF
456. Regional differences in bone mineral density biomechanically induce a higher risk of adjacent vertebral fracture after percutaneous vertebroplasty: a case-comparative study.
- Author
-
Li J, Xie Y, Sun S, Xue C, Xu W, Xu C, and Xi Z
- Subjects
- Humans, Bone Density, Retrospective Studies, Bone Cements therapeutic use, Spinal Fractures surgery, Vertebroplasty adverse effects, Osteoporotic Fractures surgery, Fractures, Compression surgery
- Abstract
Background: Adjacent vertebral fracture (AVF) is a frequently observed complication after percutaneous vertebroplasty (PVP) in patients with osteoporotic vertebral compressive fracture. Biomechanical deterioration initially induces a higher risk of AVF. Studies demonstrated that the aggravation of regional differences in the elastic modulus of different components might deteriorate the local biomechanical environment and increase the risk of structural failure. Considering the existence of intravertebral regional differences in bone mineral density (BMD) (i.e. elastic modulus), it was hypothesized in the present study that higher intravertebral BMD differences may induce a higher risk of AVF biomechanically., Materials and Methods: The radiographic and demographic data of osteoporotic vertebral compressive fracture patients treated using PVP were reviewed in the present study. The patients were divided into two groups: those with AVF and those without AVF. The Hounsfield unit (HU) values of transverse planes from the superior to the inferior bony endplate were measured, and the differences between the highest and lowest HU values of these planes were considered the regional differences of the HU value. The data from patients with and without AVF were compared, and the independent risk factors were identified through regression analysis. PVP with different grades of regional differences in the elastic modulus of the adjacent vertebral body was simulated using a previously constructed and validated lumbar finite element model, and the biomechanical indicators related to AVF were computed and recorded in surgical models., Results: Clinical data on 103 patients were collected in this study (with an average follow-up period of 24.1 months). The radiographic review revealed that AVF patients present a significantly higher regional difference in the HU value and that the increase in the regional difference of the HU value was an independent risk factor for AVF. In addition, numerical mechanical simulations recorded a stress concentration tendency (the higher maximum equivalent stress value) in the adjacent vertebral cancellous bone, with a stepwise aggravation of the adjacent cancellous bony regional stiffness differences., Conclusions: The aggravation of regional BMD differences induces a higher risk of AVF after PVP surgery through a deterioration of the local biomechanical environment. The maximum differences in the HU value of the adjacent cancellous bone should, therefore, be measured routinely to better predict the risk of AVF. Patients with noticeable regional BMD differences should be considered at high risk for AVF, and greater attention must be paid to these patients to reduce the risk of AVF., Evidence Grade: Level III b., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc.)
- Published
- 2023
- Full Text
- View/download PDF
457. Safety and clinical efficacy of endoscopic procedures for the treatment of adjacent segmental disease after lumbar fusion: A systematic review and meta-analysis.
- Author
-
Wang N, Xie Y, Liu X, Zheng Y, Xi Z, Xu W, Deng R, Tang T, and Liu X
- Subjects
- Humans, Treatment Outcome, Minimally Invasive Surgical Procedures adverse effects, Minimally Invasive Surgical Procedures methods, Lumbar Vertebrae surgery, Pain, Retrospective Studies, Randomized Controlled Trials as Topic, Endoscopy adverse effects, Endoscopy methods, Spinal Fusion adverse effects, Spinal Fusion methods
- Abstract
Background: Adjacent segment disease (ASD) is a common complication after lumbar fusion and is still traditionally treated by open surgery. In recent years, with the development of minimally invasive techniques, percutaneous endoscopic surgery(PES) has been used for the treatment of ASD after lumbar fusion due to its unique benefits. Nevertheless, it remains unclear about its significant clinical efficacy and advantages over conventional open surgery., Objectives: To evaluate the clinical efficacy and safety of PES in the treatment of ASD after lumbar fusion., Study Design: A systematic review and meta-analysis studies about the role of PES in managing ASD after lumbar fusion., Methods: A systematic search review was conducted in PubMed, EMBASE, Cochrane Library, Web of Science, CNKI, VIP, WanFang, and SinoMed databases from the start of their construction to 15 November 2021. Eligible studies included references to clinical trials of PES for ASD after open lumbar fusion. Observations included pain relief, recovery of postoperative function, overall excellent rates, and indicators of the advantages of minimally invasive surgery compared to conventional surgery. Postoperative complications and recurrence rates were also recorded., Results: A total of 24 studies, including 20 single-arm studies and 4 clinical control studies, all involving 928 patients were included. A total of 694 patients were included in the single-arm analysis. The results of the single-arm meta-analysis showed that PES could significantly reduce low back and leg pain and improve the functional status of the lumbar spine in patients with ASD after open lumbar fusion compared to preoperatively, and had good clinical efficacy after surgery. A total of 234 patients were included in the four clinically controlled studies, and the results of the meta-analysis showed that PES could clearly reduce pain and improve lumbar function, with no significant difference in efficacy between PES and open surgery. However, PES has a lower surgical incision, less intraoperative bleeding, and shorter operative time and length of hospital stay compared to open surgery. Moreover, it has a lower rate of postoperative recurrence as well as complications and a longer duration of efficacy., Conclusions: On the basis of the available clinical literature and the results of this study, PES could achieve satisfactory clinical effects in ASD treatment after lumbar fusion. Compared with conventional open surgery, PES can not only obtain similar clinical results, but also had the advantages of less trauma and faster recovery. Nevertheless, a randomized controlled study is still needed to validate the findings of this study., Trial Registration: Systematic review registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42022298387., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Wang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
- Published
- 2023
- Full Text
- View/download PDF
458. The adaptation of bovine embryonic stem cells to the changes of feeder layers.
- Author
-
Xu W, Gao L, Li W, Wang J, Yue Y, and Li X
- Subjects
- Animals, Cattle, Mice, Feeder Cells, Embryonic Stem Cells, Cell Differentiation, Fibroblasts, Pluripotent Stem Cells
- Abstract
Although the feeder-free culture system has been established, the microenvironment provided by the feeder cells still possesses a unique advantage in maintaining the long-term stability and the rapid proliferation of pluripotent stem cells (PSCs). The aim of this study is to discover the adaptive ability of PSCs upon changes of feeder layers. In this study, the morphology, pluripotent marker expression, differentiation ability of bovine embryonic stem cells (bESCs) cultured on low-density, or methanol fixed mouse embryonic fibroblasts were examined by immunofluorescent staining, Western blotting, real-time reverse transcription polymerase chain reaction, and RNA-seq. The results showed that the changes of feeder layers did not induce the rapid differentiation of bESCs, while resulting in the differentiation initiation and alteration of pluripotent state of bESCs. More importantly, the expression of endogenous growth factors and extracellular matrix were increased, and the expression of cell adhesion molecules was altered, which indicated that bESCs may compensate some functions of the feeder layers upon its changes. This study shows the PSCs have the self-adaptive ability responded to the feeder layer alteration., (© 2023. The Society for In Vitro Biology.)
- Published
- 2023
- Full Text
- View/download PDF
459. Exogenous pyruvate and recombinant human basic fibroblast growth factor maintain pluripotency and enhance global metabolic activity of bovine embryonic stem cells grown on low-density feeder layers.
- Author
-
Xu W, Wang J, Li W, Gao L, Hao R, Han X, Li C, Zhang H, and Li X
- Subjects
- Cattle, Animals, Humans, Feeder Cells, Embryonic Stem Cells, Pyruvic Acid pharmacology, Metabolomics
- Abstract
A suitable microenvironment or niche is essential for self-renewal and pluripotency of stem cells cultured in vitro, including bovine embryonic stem cells (bESCs). Feeder cells participate in the construction of stem cell niche by secreting growth factors and extracellular matrix proteins. In this study, metabolomics and transcriptomics analyses were used to investigate the effects of low-density feeder cells on bESCs. The results showed that bESCs co-cultured with low-density feeder cells experienced a decrease in pluripotent gene expression, cell differentiation, and a reduction of central carbon metabolic activity. When cell-permeable pyruvate (Pyr) and recombinant human basic fibroblast growth factor (rhbFGF) were added to the culture system, the pluripotency of bESCs on low-density feeder layers was rescued, and acetyl-coenzyme A (AcCoA) synthesis and fatty acid de novo synthesis increased. In addition, rhbFGF enhances the effects of Pyr and activates the overall metabolic level of bESCs grown on low-density feeder layers. This study explored the rescue effects of exogenous Pyr and rhbFGF on bESCs cultured on low-density feeder layers, which will provide a reference for improvement of the PSC culture system through the supplementation of energy metabolites and growth factors., Competing Interests: Declaration of competing interest The authors indicate no potential conflicts of interest., (Copyright © 2022 Elsevier Inc. All rights reserved.)
- Published
- 2023
- Full Text
- View/download PDF
460. Fermentative Production of Diacylglycerol by Endophytic Fungi Screened from Taxus chinensis var. mairei .
- Author
-
Xu W, Bi H, Peng H, Yang L, He H, Fu G, Liu Y, and Wan Y
- Abstract
Diacylglycerol (DAG) production by microbial fermentation has broad development prospects. In the present study, five endophytic fungi which could accumulate DAG were screened from Taxus chinensis var. mairei by using potato dextrose agar plate and flask cultivation in potato dextrose broth culture medium. The strains were biologically identified based on morphological features and semi-quantitative PCR. The identification results indicated that the five strains belonged to different genera: Fusarium annulatum ( F. annulatum, coded as MLP41), Trichoderma dorotheae ( T. dorotheae, coded as MLG23), Colletotrichum aeschynomenes ( C. aeschynomenes, coded as MLY23), Pestalotiopsis scoparia ( P. scoparia, coded as MLY31W), and Penicillium cataractarum ( P. cataractarum, coded as MLGP11). The crude lipids from the strains and their corresponding triacylglycerol, 1,2-DAG, and 1,3-DAG fractions separated via thin-layer chromatography were mainly composed of palmitic acid, stearic acid, oleic acid, and linoleic acid, which in total accounted for higher than 94% of the content. The effects of fermentation conditions on the DAG productivity were discussed, and the yields of DAG were determined based on the
1 H NMR spectra of crude lipids. The highest total DAG yields of F. annulatum , T. dorotheae , C. aeschynomenes , P. scoparia , and P. cataractarum were 112.28, 126.42, 189.87, 105.61, and 135.56 mg/L, respectively. C. aeschynomenes had the strongest potential to produce DAG. The results showed that this may be a new promising route for the production of DAG via fermentation by specific endophytic fungi, such as C. aeschynomenes .- Published
- 2023
- Full Text
- View/download PDF
461. Simulation and Experimental Analysis of Surface Defects in Turning of TiC p /TC4 Composites.
- Author
-
Huan H, Zhu C, Zhao B, Xu W, and Zhang K
- Abstract
Processing TiCp/TC4 composites has always been difficult due to the mismatch between the mechanical and thermal properties of the matrix and the reinforced particles, which results in a variety of machined surface defects. To expose the mechanism of defect generated on the cutting surface of TiCp/TC4 composites and improve their cutting surface quality, a 3D finite element orthogonal turning simulation model of TiCp/TC4 composites is developed. The failure at the matrix-particle interface and the fracture and removal mechanism of the reinforcing phase particles are analyzed from a microscopic perspective using a single particle cutting simulation model. In addition, a three-dimensional cutting simulation model with randomly dispersed TiC particles and a volume fraction of 5% is developed, and various forms of cutting surface defects of TiCp/TC4 composites are examined. To verify the validity of the finite element simulation model, TiCp/TC4 composites with a volume fraction of 5% are selected for turning tests. For various cutting tools and particle relative positions, the simulation and test results show that the removal of particles takes the following forms: debonding, crushing, brittle fracture, and slight fracture at the top, leading to a shallow cavity, microcracks, residual TiC particles embedded in the cavity, and surface defects with severe plastic deformation of the matrix surrounding the cavity on the machined surface.
- Published
- 2022
- Full Text
- View/download PDF
462. Resveratrol Improves the Digestive Ability and the Intestinal Health of Siberian Sturgeon.
- Author
-
Yang S, Xu W, Feng L, Zhang C, Yan C, Zhang J, Lai J, Yan T, He Z, Du X, Du Z, Luo W, Huang X, Wu J, and Li Y
- Subjects
- Animals, Diet, Fishes, Intestines chemistry, Lipase, Resveratrol pharmacology, alpha-Amylases, Animal Feed analysis, Pepsin A
- Abstract
The lack of detailed information on nutritional requirement results in limited feeding in Siberian sturgeon. In this study, resveratrol, a versatile natural extract, was supplemented in the daily diet, and the digestive ability and microbiome were evaluated in the duodena and valvular intestines of Siberian sturgeon. The results showed that resveratrol increased the activity of pepsin, α-amylase, and lipase, which was positively associated with an increase in the digestive ability, but it did not influence the final body weight. Resveratrol improved the digestive ability probably by distinctly enhancing intestinal villus height. Microbiome analysis revealed that resveratrol changed the abundance and composition of the microbial community in the intestine, principally in the duodenum. Random forests analysis found that resveratrol significantly downregulated the abundance of potential pathogens ( Citrobacter freundii , Vibrio rumoiensis , and Brucella melitensis ), suggesting that resveratrol may also improve intestinal health. In summary, our study revealed that resveratrol improved digestive ability and intestinal health, which can contribute to the development of functional feed in Siberian sturgeon.
- Published
- 2022
- Full Text
- View/download PDF
463. Inhibition Effect and Mechanism Explanation of Perilla Seed Extract as a Green Corrosion Inhibitor on Q235 Carbon Steel.
- Author
-
Li Y, Xu W, Lai J, and Qiang S
- Abstract
The development of environmentally friendly corrosion inhibitors has become a research hotspot. Aiming at the potential corrosion inhibition effect of perilla seed extract on Q235 carbon steel, the corrosion inhibition effect was quantitatively evaluated by various research methods, and the effective corrosion inhibition composition and mechanism were discussed. The research methods include potentiodynamic polarization curve method, HPLC-MS, FT-IR, XPS and chemical calculation. The experimental results show that the inhibitor prepared from perilla seed extract is a mixed inhibitor, and its adsorption behavior accords with Langmuir adsorption theory and its adsorption free energy is -22.70 kJ/mol. Combined with the experimental results and theoretical calculation, the effective corrosion inhibiting components are luteolin and apigenin. Theoretical calculation shows that both of them are adsorbed parallel to the surface of carbon steel to form thin films. The adsorption mechanism is that carbonyl O atoms in luteolin and apigenin hybridize with the 3 d empty orbit of Fe. From the point of view of quantum chemistry, the smaller the HOMO value and the energy gap value, the better the adsorption of corrosion inhibitor on the surface of carbon steel. From the point of view of molecular dynamics simulation, the greater the absolute value of adsorption energy, the better the adsorption of corrosion inhibitor on carbon steel surface.
- Published
- 2022
- Full Text
- View/download PDF
464. Methanol fixed feeder layers altered the pluripotency and metabolism of bovine pluripotent stem cells.
- Author
-
Xu W, Hao R, Wang J, Gao L, Han X, Li C, Fang S, Zhang H, and Li X
- Subjects
- Animals, Cattle, Cell Culture Techniques methods, Cell Differentiation, Feeder Cells metabolism, Fibroblasts, Mice, Mitomycin metabolism, Methanol metabolism, Pluripotent Stem Cells metabolism
- Abstract
The pluripotency maintenance of pluripotent stem cells (PSCs) requires the suitable microenvironment, which commonly provided by feeder layers. However, the preparation of feeder layers is time consuming and labor exhaustive, and the feeder cells treated with mitomycin C or γ-ray irradiation bring heterologous contamination. In this study, mouse embryonic fibroblasts (MEFs) were treated by methanol to generate chemical fixed feeder cells, and bovine embryonic stem cells F7 (bESC-F7) cultured on this feeder layer. Then the pluripotency and metabolism of bESC-F7 cultured on methanol-fixed MEFs (MT-MEFs) named MT-F7 was compared with mitomycin C treated MEFs (MC-MEFs). The results showed that bESC-F7 formed alkaline phosphatase positive colonies on MT-MEFs, the relative expression of pluripotent markers of these cells was different from the bESCs cultured on the MC-MEFs (MC-F7). The long-term cultured MT-F7 formed embryoid bodies, showed the ability to differentiate into three germ layers similar to MC-F7. The analyses of RNA-seq data showed that MT-MEFs lead bESCs to novel steady expression patterns of genes regulating pluripotency and metabolism. Furthermore, the bovine expanded pluripotent stem cells (bEPSCs) cultured on MT-MEFs formed classical colonies, maintained pluripotency, and elevated metabolism. In conclusion, MT-MEFs were efficient feeder layer that maintain the distinctive pluripotency and metabolism of PSCs., (© 2022. The Author(s).)
- Published
- 2022
- Full Text
- View/download PDF
465. Exosomes derived from fibrinogen-like protein 1-overexpressing bone marrow-derived mesenchymal stem cells ameliorates rheumatoid arthritis.
- Author
-
Xu W, Liu X, Qu W, Wang X, Su H, Li W, and Cheng Y
- Subjects
- Rats, Animals, Fibrinogen genetics, Fibrinogen metabolism, Bone Marrow metabolism, Inflammation metabolism, Exosomes metabolism, Arthritis, Rheumatoid genetics, Arthritis, Rheumatoid therapy, Arthritis, Rheumatoid metabolism, Mesenchymal Stem Cells metabolism
- Abstract
Rheumatoid arthritis (RA) is a most common chronic joint disease belonging to inflammatory autoimmune disease. The aim of this study was to determine the role and mechanism of bone marrow mesenchymal stem cells (BMSCs)-derived exosomes and fibrinogen-like protein 1 (FGL1) overexpression exosomes shuttled by BMSCs (FGL1-Exos) on RA. All of the exosomes were visualized by transmission electron microscope (TEM) and the characteristic proteins were detected by western blot. To investigate the therapeutic effect of FGL1-Exos, RA-FLSs were activated by TNF-α and RA rat model was established by collagen incomplete Freund's adjuvant. Cell viability, apoptosis, inflammation factors, and protein levels were detected by CCK-8, flow cytometry, enzyme-linked immunosorbent assay and western blot, respectively. Hematoxylin and eosin and safranin O staining were used to detect the histopathology changes. Cell apoptosis and FGL1 expression in knee joint were detected by immunofluorescence. The results showed that FGL1-Exos could inhibit the cell viability meanwhile increase the cell apoptosis in RA-FLSs. Meanwhile, FGL1-Exos could effectively suppress the inflammation score, joint destruction, and inflammatory response in RA rat model. FGL1-Exos directly inhibited cell apoptosis of RA-FLSs and RA rat model by suppressing the inflammatory cytokines, specific rheumatoid markers, immunological markers meanwhile meditating the NF-κB pathway. Our results indicate that FGL1 was a therapeutic potential target in RA therapy.
- Published
- 2022
- Full Text
- View/download PDF
466. Layer-by-layer stacked vanadium nitride nanocrystals/N-doped carbon hybrid nanosheets toward high-performance aqueous zinc-ion batteries.
- Author
-
Niu Y, Xu W, Ma Y, Gao Y, Li X, Li L, and Zhi L
- Abstract
Aqueous zinc ion batteries (AZIBs) hold great potential in large scale, low-cost energy storage. Unfortunately, their development is limited by the poor performing cathode materials due to their unstable structures and low capacities. Hence, we develop novel layer-by-layer stacked vanadium nitride nanocrystals/N-doped carbon hybrid nanosheets (VN/NC) as cathode materials by in situ thermal conversion of pyrolyzing pentyl viologen intercalated V
2 O5 . The combination of a leaf-like morphology, the nano structure of vanadium nitride crystals and the conductive porous nitrogen-doped carbon nanosheets endow the VN/NC cathode with excellent electrochemical performance in AZIBs. Thus, it delivers a high discharge specific capacity of 566 mA h g-1 at a current density of 0.2 A g-1 and a superior rate capability. Most importantly, it exhibits a remarkable cyclic stability with capacity retention of 131 mA h g-1 (85% of the initial capacity) after 1000 cycles at a current density of 10 A g-1 . The design of the unique VN/NC hybrid nano sheets offers a pathway towards developing high performance electrode materials for energy storage.- Published
- 2022
- Full Text
- View/download PDF
467. The N6-methyladenosine modification enhances ferroptosis resistance through inhibiting SLC7A11 mRNA deadenylation in hepatoblastoma.
- Author
-
Liu L, He J, Sun G, Huang N, Bian Z, Xu C, Zhang Y, Cui Z, Xu W, Sun F, Zhuang C, Man Q, and Gu S
- Subjects
- Adenosine analogs & derivatives, Adenosine pharmacology, Animals, Humans, Methyltransferases genetics, Methyltransferases metabolism, RNA, Messenger genetics, Tumor Suppressor Proteins metabolism, Amino Acid Transport System y+ genetics, Amino Acid Transport System y+ metabolism, Ferroptosis genetics, Hepatoblastoma genetics, Immediate-Early Proteins metabolism, Liver Neoplasms genetics, Liver Neoplasms metabolism, Liver Neoplasms pathology
- Abstract
Background: Solute carrier family 7 member 11 (SLC7A11) is overexpressed in multiple human tumours and functions as a transporter importing cystine for glutathione biosynthesis. It promotes tumour development in part by suppressing ferroptosis, a newly identified form of cell death that plays a pivotal role in the suppression of tumorigenesis. However, the role and underlying mechanisms of SLC7A11-mediated ferroptosis in hepatoblastoma (HB) remain largely unknown., Methods: Reverse transcription quantitative real-time PCR (RT-qPCR) and western blotting were used to measure SLC7A11 levels. Cell proliferation, colony formation, lipid reactive oxygen species (ROS), MDA concentration, 4-HNE, GSH/GSSG ratio and cell death assays as well as subcutaneous xenograft experiments were used to elucidate the effects of SLC7A11 in HB cell proliferation and ferroptosis. Furthermore, MeRIP-qPCR, dual luciferase reporter, RNA pulldown, RNA immunoprecipitation (RIP) and RACE-PAT assays were performed to elucidate the underlying mechanism through which SLC7A11 was regulated by the m6A modification in HB., Results: SLC7A11 expression was highly upregulated in HB. SLC7A11 upregulation promoted HB cell proliferation in vitro and in vivo, inhibiting HB cell ferroptosis. Mechanistically, SLC7A11 mRNA exhibited abnormal METTL3-mediated m6A modification, which enhanced its stability and expression. IGF2 mRNA-binding protein 1 (IGF2BP1) was identified as the m6A reader of SLC7A11, enhancing SLC7A11 mRNA stability and expression by inhibiting SLC7A11 mRNA deadenylation in an m6A-dependent manner. Moreover, IGF2BP1 was found to block BTG2/CCR4-NOT complex recruitment via competitively binding to PABPC1, thereby suppressing SLC7A11 mRNA deadenylation., Conclusions: Our findings demonstrated that the METTL3-mediated SLC7A11 m6A modification enhances HB ferroptosis resistance. The METTL3/IGF2BP1/m6A modification promotes SLC7A11 mRNA stability and upregulates its expression by inhibiting the deadenylation process. Our study highlights a critical role of the m6A modification in SLC7A11-mediated ferroptosis, providing a potential strategy for HB therapy through blockade of the m6A-SLC7A11 axis., (© 2022 The Authors. Clinical and Translational Medicine published by John Wiley & Sons Australia, Ltd on behalf of Shanghai Institute of Clinical Bioinformatics.)
- Published
- 2022
- Full Text
- View/download PDF
468. Rh-Catalyzed [4 + 2] Annulation with a Removable Monodentate Structure toward Iminopyranes and Pyranones by C-H Annulation.
- Author
-
Fu L, Xu W, Pu M, Wu YD, Liu Y, and Wan JP
- Subjects
- Alkynes chemistry, Catalysis, Rhodium chemistry
- Abstract
The Rh-catalyzed reactions of N -pyridinyl enaminones with internal alkynes leading to the synthesis of iminopyranes via a key C-H bond activation and subsequent tautomeric O-H bond cleavage are reported. Moreover, the pyridine ring in the amino group acts as an auxiliary monodentate site for this annulation and can be easily removed by a simple hydrolysis to afford pyranones.
- Published
- 2022
- Full Text
- View/download PDF
469. Heat Stress Weakens the Skin Barrier Function in Sturgeon by Decreasing Mucus Secretion and Disrupting the Mucosal Microbiota.
- Author
-
Yang S, Xu W, Tan C, Li M, Li D, Zhang C, Feng L, Chen Q, Jiang J, Li Y, Du Z, Luo W, Li C, Gong Q, Huang X, Du X, Du J, Liu G, and Wu J
- Abstract
Heat stress induced by global warming has damaged the well-being of aquatic animals. The skin tissue plays a crucial role as a defense barrier to protect organism, however, little is known about the effect of heat stress on fish skin, particularly in cold-water fish species. Here, we investigated the effects of mild heat stress (24°C, MS) and high heat stress (28°C, HS) on Siberian sturgeon skin using RNA-seq, histological observation, and microbial diversity analysis. In RNA-seq, 8,819 differentially expressed genes (DEGs) in MS vs. C group and 12,814 DEGs in HS vs. C group were acquired, of which the MS vs. C and HS vs. C groups shared 3,903 DEGs, but only 1,652 DEGs were successfully annotated. The shared DEGs were significantly enriched in pathways associating with mucins synthesis. Histological observation showed that the heat stresses significantly reduced the number of skin mucous cells and induced the damages of epidermis. The microbial diversity analysis elicited that heat stress markedly disrupted the diversity and abundance of skin microbiota by increasing of potential pathogens ( Vibrionimonas , Mesorhizobium , and Phyllobacterium ) and decreasing of probiotics ( Bradyrhizobium and Methylovirgula ). In conclusion, this study reveals that heat stress causes adverse effects on sturgeon skin, reflecting in decreasing the mucus secretion and disordering the mucosal microbiota, which may contribute to develop the preventive strategy for heat stress caused by global warming., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Yang, Xu, Tan, Li, Li, Zhang, Feng, Chen, Jiang, Li, Du, Luo, Li, Gong, Huang, Du, Du, Liu and Wu.)
- Published
- 2022
- Full Text
- View/download PDF
470. Biochemical characterization of a thermophilic exo-arabinanase from the filamentous fungus Rasamsonia emersonii.
- Author
-
An J, Xu W, Meng X, Chen G, Zhang W, and Liu W
- Subjects
- Arabinose, Substrate Specificity, Eurotiales enzymology, Fungal Proteins metabolism, Glycoside Hydrolases metabolism
- Abstract
Arabinan in plant cell wall constitutes a major source of arabinose and arabino-oligosaccharides in nature. Exo-α-l-1,5-arabinanases release arabinose or arabino-oligosaccharides from arabinan in an exo-acting manner and therefore contribute to arabinan degradation. In this study, an exo-α-l-1,5-arabinanase belonging to GH93 family was identified from the thermophilic filamentous fungus Rasamsonia emersonii. The corresponding encoding gene (Reabn93) was cloned from the R. emersonii genome and heterologously expressed in Pichia pastoris. The purified recombinant ReAbn93 exhibited the maximum activity at 70 °C and retained 70% of its activity after incubation at 70 °C for 3 h ReAbn93 had an acidic pH optimum (pH 4.0) but remained stable over a broad pH range (pH 3-9). The specific activity of ReAbn93 toward linear arabinan under optimal conditions was 466.08 U mg
-1 . Similar to the few other reported GH93 members, ReAbn93 degrades linear arabinan or arabino-oligosaccharides in an exo-acting manner with arabinobiose as the only hydrolytic product. Of note, ReAbn93 possessed remarkably better thermostability and higher specific activity compared to the only reported thermophilic counterpart in GH93, and therefore holds potential in relevant biotechnological applications., (Copyright © 2021 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.)- Published
- 2022
- Full Text
- View/download PDF
471. Heat Stress Decreases Intestinal Physiological Function and Facilitates the Proliferation of Harmful Intestinal Microbiota in Sturgeons.
- Author
-
Yang S, Zhang C, Xu W, Li D, Feng Y, Wu J, Luo W, Du X, Du Z, and Huang X
- Abstract
Heat is a common source of stress in aquatic environments and can alter the physiological and metabolic functions of aquatic animals, especially their intestinal function. Here, the effects of heat stress on the structure and function of the intestine and the characteristics of the intestinal microbiota were studied in sturgeon ( Acipenser baerii ♀ × Acipenser schrenckii ♂ hybrid F1). Sturgeons were exposed to sub-extreme (24°C) and extreme (28°C) high water temperatures for 12 days. The heat stress caused systemic damage to the intestine of sturgeons, which displayed severe enteritis in the valve intestine. The microbial diversity analysis showed that heat stress led to the disorder in intestinal microbiota, manifesting as an explosive increase in the abundance of thermophilic intestinal pathogens such as Plesiomonas , Cetobacterium , and Aeromonas and causing physiological dysfunction in the sturgeons. The disorder was followed by significant inhibition of intestinal digestion with reduced chymotrypsin, α-amylase, and lipase activities in the valve intestine and of antioxidant function with reduced peroxidase (POD) and catalase (CAT) activities. Simultaneously, heat stress reduced the thermal tolerance of sturgeons by reducing Grp75 expression and damaged the valve intestine's repair ability with increased Tgf- β expression. The results confirmed that heat stress damaged the sturgeon intestines obviously and disturbed the intestinal microbiota, resulting in serious physiological dysfunction. The present study investigated the mechanism of the effect of heat stress on the sturgeon intestine and will help develop strategies to improve the resistance to thermal stress for wild and cultured sturgeons., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Yang, Zhang, Xu, Li, Feng, Wu, Luo, Du, Du and Huang.)
- Published
- 2022
- Full Text
- View/download PDF
472. Elimination of the Sugar Transporter GAT1 Increased Xylanase I Production in Trichoderma reesei .
- Author
-
Xu W, Fang Y, Ding M, Ren Y, Meng X, Chen G, Zhang W, and Liu W
- Abstract
The filamentous fungus Trichoderma reesei secretes large quantities of cellulases and hemicellulases that have found wide applications in industry. Compared with extensive studies on the mechanism controlling cellulase gene expression, less is known about the regulatory mechanism behind xylanase gene expression. Herein, several putative sugar transporter encoding genes that showed significant upregulation on xylan were identified in T . reesei . Deletion of one such gene, gat1 , resulted in increased xylanase production but hardly affected cellulase induction. Further analyses demonstrated that deletion of gat1 markedly increased XYNI production at the transcriptional level and only exerted a minor effect on XYNII synthesis. In contrast, overexpressing gat1 caused a continuous decrease in xyn1 expression. Deletion of gat1 also affected the expression of xyn1 and pectinase genes when T . reesei was cultivated with galacturonic acid as the sole carbon source. Transcriptome analyses of Δ gat1 and its parental strain identified 255 differentially expressed genes that are enriched in categories of glycoside hydrolases, lipid metabolism, transporters, and transcriptional factors. The results thus implicate a repressive role of the sugar transporter GAT1 in xyn1 expression and reveal that distinct regulatory mechanisms may exist in controlling the expression of different xylanase genes in T . reesei ., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Xu, Fang, Ding, Ren, Meng, Chen, Zhang and Liu.)
- Published
- 2022
- Full Text
- View/download PDF
473. Toward Real-World Category-Level Articulation Pose Estimation.
- Author
-
Liu L, Xue H, Xu W, Fu H, and Lu C
- Abstract
Human life is populated with articulated objects. Current Category-level Articulation Pose Estimation (CAPE) methods are studied under the single-instance setting with a fixed kinematic structure for each category. Considering these limitations, we aim to study the problem of estimating part-level 6D pose for multiple articulated objects with unknown kinematic structures in a single RGB-D image, and reform this problem setting for real-world environments and suggest a CAPE-Real (CAPER) task setting. This setting allows varied kinematic structures within a semantic category, and multiple instances to co-exist in an observation of real world. To support this task, we build an articulated model repository ReArt-48 and present an efficient dataset generation pipeline, which contains Fast Articulated Object Modeling (FAOM) and Semi-Authentic MixEd Reality Technique (SAMERT). Accompanying the pipeline, we build a large-scale mixed reality dataset ReArtMix and a real world dataset ReArtVal. Accompanying the CAPER problem and the dataset, we propose an effective framework that exploits RGB-D input to estimate part-level pose for multiple instances in a single forward pass. In our method, we introduce object detection from RGB-D input to handle the multi-instance problem and segment each instance into several parts. To address the unknown kinematic structure issue, we propose an Articulation Parsing Network to analyze the structure of detected instance, and also build a Pair Articulation Pose Estimation module to estimate per-part 6D pose as well as joint property from connected part pairs. Extensive experiments demonstrate that the proposed method can achieve good performance on CAPER, CAPE and instance-level Robot Arm pose estimation problems. We believe it could serve as a strong baseline for future research on the CAPER task. The datasets and codes in our work will be made publicly available.
- Published
- 2022
- Full Text
- View/download PDF
474. Improved Visual Recognition Memory Model Based on Grid Cells for Face Recognition.
- Author
-
Liu J, Xu W, Li X, and Zheng X
- Abstract
Traditional facial recognition methods depend on a large number of training samples due to the massive turning of synaptic weights for low-level feature extractions. In prior work, a brain-inspired model of visual recognition memory suggested that grid cells encode translation saccadic eye movement vectors between salient stimulus features. With a small training set for each recognition type, the relative positions among the selected features for each image were represented using grid and feature label cells in Hebbian learning. However, this model is suitable only for the recognition of familiar faces, objects, and scenes. The model's performance for a given face with unfamiliar facial expressions was unsatisfactory. In this study, an improved computational model via grid cells for facial recognition was proposed. Here, the initial hypothesis about stimulus identity was obtained using the histograms of oriented gradients (HOG) algorithm. The HOG descriptors effectively captured the sample edge or gradient structure features. Thus, most test samples were successfully recognized within three saccades. Moreover, the probability of a false hypothesis and the average fixations for successful recognition were reduced. Compared with other neural network models, such as convolutional neural networks and deep belief networks, the proposed method shows the best performance with only one training sample for each face. Moreover, it is robust against image occlusion and size variance or scaling. Our results may give insight for efficient recognition with small training samples based on neural networks., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Liu, Xu, Li and Zheng.)
- Published
- 2021
- Full Text
- View/download PDF
475. Asymmetric Domino Heck Arylation and Alkylation of Nonconjugated Dienes: Double C-F···Sodium Attractive Noncovalent Interaction.
- Author
-
Zhu D, Xu W, Pu M, Wu YD, Chi YR, and Zhou JS
- Abstract
Palladium catalyzes a domino Heck arylation and alkylation of nonconjugated cyclodienes to produce trans isomers of disubstituted cyclohexenes in exceptionally high enantiomeric ratios, reaching 100:1 to 200:1 in many cases. Importantly, the interactions of the two CF bonds of Josiphos and the sodium ion of malonates facilitates stereoselective allylic attack through DFT calculations and experiments. This is a new type of attractive noncovalent interactions found in organometallic catalysis.
- Published
- 2021
- Full Text
- View/download PDF
476. Induction of Bone Remodeling by Raloxifene-Doped Iron Oxide Functionalized with Hydroxyapatite to Accelerate Fracture Healing.
- Author
-
Wang G, Xu W, Zhang J, Tang T, Chen J, and Fan C
- Subjects
- Bone Remodeling, Ferric Compounds, Fracture Healing, Durapatite, Raloxifene Hydrochloride pharmacology
- Abstract
Repairing fractures in the presence of infection is a major challenge that is currently declining using nanotechnology. By producing iron oxide nanoparticles (NPs) containing hydroxyapatite and Raloxifene (R-IONPs-HA), this study tries to target drug delivery, control infection and promotion of the cells proliferation/differentiation to repair damaged tissue. After the production of R-IONPs-HA through co-precipitation, the physicochemical features of the NPs were considered by SEM, TEM, DLS and XRD methods, and the possibility of drug release. The effect of R-IONPs-HA on MC3T3-E1 cell proliferation/differentiation was determined by CCK-assay and microscopic observations. Also, Gram-negative and -positive bacteria were applied to evaluate the antibacterial activity. Finally, cell differentiation biomarkers like an ALP, OCN, and RUNX-2 genes were examined by real time (RT)-PCR. The results showed that R-IONPs-HA was spherical with dimensions of 98.1 ± 1.17 nm. In addition, the results of Zeta and XRD confirmed the loading HA and R on IONPs. Also, the release rate of R and HA in 64 h with pH 6 reached 61.4 and 30.4%, respectively. The anti-bacterial activity of R-IONPs-HA on Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa bacteria showed a significant reduction in infection. Also, MC3T3-E1 cells showed greater proliferation and differentiation by R-IONPs-HA compared to other groups. Increased expression of ossification genes such as OCN, and RUNX-2 confirmed this claim. Finally, R-IONPs-HA with good biocompatibility, antibacterial activity and ossification induction has great potential to repair bone fractures and prevent infection.
- Published
- 2021
- Full Text
- View/download PDF
477. Assessment of Carbon Density in Natural Mountain Forest Ecosystems at Northwest China.
- Author
-
Dai L, Zhang Y, Wang L, Zheng S, and Xu W
- Subjects
- Biomass, Carbon Sequestration, China, Forests, Soil, Trees, Carbon analysis, Ecosystem
- Abstract
The natural mountain forests in northwest China are recognized as a substantial carbon pool and play an important role in local fragile ecosystems. This study used inventory data and detailed field measurements covering different forest age groups (young, middle-aged, near-mature, mature, old-growth forest), structure of forest (tree, herb, litter and soil layer) and trees (leaves, branches, trunks and root) to estimate biomass, carbon content ratio, carbon density and carbon storage in Altai forest ecosystems. The results showed that the average biomass of the Altai Mountains forest ecosystems was 126.67 t·hm
-2 , and the descending order of the value was tree layer (120.84 t·hm-2 ) > herb layer (4.22 t·hm-2 ) > litter layer (1.61 t·hm-2 ). Among the tree parts, trunks, roots, leaves and branches accounted for 50%, 22%, 16% and 12% of the total tree biomass, respectively. The average carbon content ratio was 0.49 (range: 0.41-0.52). The average carbon density of forest ecosystems was 205.72 t·hm-2 , and the carbon storage of the forest ecosystems was 131.35 Tg (standard deviation: 31.01) inside study area. Soil had the highest carbon storage (65.98%), followed by tree (32.81%), herb (0.78%) and litter (0.43%) layers. Forest age has significant effect on biomass, carbon content ratio, carbon density and carbon storage. The carbon density of forest ecosystems in study area was spatially distributed higher in the south and lower in north, which is influenced by climate, topography, soil types and dominant tree species.- Published
- 2021
- Full Text
- View/download PDF
478. Scalable synthesis of silicon nanoplate-decorated graphite for advanced lithium-ion battery anodes.
- Author
-
Li H, Li X, Wang D, Zhang S, Xu W, Zhu LN, and Zhi L
- Abstract
A silicon nanoplate-decorated graphite design is developed for lithium battery anodes via a simple ball milling process. The resultant silicon-graphite electrodes show high cycling stability with high capacity, superior rate capability, and excellent electrode stability when compared to their counterparts, attributable to two-dimensional silicon and its area-to-area contact with graphite.
- Published
- 2021
- Full Text
- View/download PDF
479. [Short-term effectiveness of Endobutton plate in reconstruction of Lisfranc ligament].
- Author
-
Wang W, Fan Y, Liu C, Xu W, Ma X, Xu J, and Yu H
- Subjects
- Adolescent, Adult, Bone Screws, Female, Humans, Ligaments, Articular surgery, Male, Middle Aged, Retrospective Studies, Treatment Outcome, Young Adult, Bone Plates, Fracture Fixation, Internal
- Abstract
Objective: To observe the short-term effectiveness of Endobutton plate in the reconstruction of Lisfranc ligament in tarsometatarsal joint injury., Methods: Between March 2015 and July 2018, 18 patients with tarsometatarsal joint injuries were treated with Lisfranc ligament reconstruction by Endobutton plate. There were 12 males and 6 females with an average age of 32.5 years (range, 16-55 years). The causes of injury were traffic accident in 8 cases, falling from height in 3 cases, crushing by a heavy objective in 4 cases, and spraining in 3 cases. There were 10 cases of Myerson type A, 4 of type B1, 2 of type B2, 1 of type C1, and 1 of type C2. The interval between injury and operation ranged from 3 to 9 days (mean, 4.9 days). X-ray examination was performed regularly after operation to measure the distance between the first and the second metatarsal joints, and the visual analogue scale (VAS) score was used to evaluate the pain relief. At last follow-up, the reduction of tarsometatarsal joint was evaluated by measuring and comparing the height of the affected and healthy arches. The foot function was evaluated according to the American Orthopaedic Foot and Ankle Society (AOFAS) score., Results: The average follow-up time was 15.8 months (range, 10-28 months). All incisions healed by first intention. X-ray reexamination showed that there was no screw loosening or plate fracture. There were significant differences in the distance between the first and the second metatarsal joints and VAS score at 3 months after operation, before removal of the internal fixator, and at last follow-up when compared with preoperative values ( P <0.05). There was no significant difference between the time points after operation ( P >0.05). At last follow-up, there was no significant difference in the arch height between affected foot [(5.3±0.2) mm] and healthy foot [(5.4± 0.3) mm] ( t =1.798, P =0.810). The AOFAS score of foot function was 89.5±7.3 with excellent in 12 cases, good in 4 cases, and fair in 2 cases. The excellent and good rate was 88.9%., Conclusion: The reconstruction of Lisfranc ligament with Endobutton plate can stabilize the tarsometatarsal joint and achieve satisfactory foot function at early stage.
- Published
- 2020
- Full Text
- View/download PDF
480. [Application of self-designed adjustable operation frame in treatment of severe kyphosis secondary to ankylosing spondylitis with posterior osteotomy].
- Author
-
Zhang W, Yu H, Wang H, Zhai Y, Dong L, Zheng G, Xu W, and Zhang X
- Subjects
- Adult, Female, Humans, Lumbar Vertebrae surgery, Male, Middle Aged, Osteotomy, Treatment Outcome, Kyphosis etiology, Kyphosis surgery, Spondylitis, Ankylosing complications, Spondylitis, Ankylosing surgery
- Abstract
Objective: To introduce a self-designed adjustable operation frame and explore the feasibility and safety in the treatment of severe kyphosis secondary to ankylosing spondylitis with posterior osteotomy., Methods: Between March 2016 and May 2018, 7 cases of severe kyphosis secondary to ankylosing spondylitis were treated with posterior osteotomy using self-designed adjustable operation frame with prone position. There were 5 males and 2 females with an average age of 49.4 years (range, 40-55 years). The disease duration was 10-21 years (mean, 16.7 years). The apical vertebrae of kyphosis were located at T
11 in 2 cases, T12 in 1 case, L1 in 1 case, and L2 in 3 cases. Among the 7 cases, 2 were classified as typeⅠ, 4 as type ⅡB, and 1 as type ⅢA according to 301 classification system. There was no neurological deficit of all cases; but 1 case suffered bilateral hip joints ankylosed in non-functional position. The parameters of chin-brow vertical angle (CBVA), global kyphosis (GK), thoracolumbar kyphosis (TLK), lumbar lordosis (LL), sagittal vertical axis (SVA) were measured; and the operation time, the intraoperative blood loss, and the complications were also collected and analyzed., Results: All operations completed successfully. The operation time was 310-545 minutes (mean, 409.7 minutes) and the intraoperative blood loss was 1 500-2 500 mL (mean, 1 642.9 mL). There were 2 cases treated with one-level osteotomy of sagittal translation, 1 case of radiculopathy symptom of L3 , and 3 cases of tension of abdominal skin. All patients were followed up 20-35 months (mean, 27.9 months). There were significant differences in CBVA, GK, TLK, LL, and SVA between pre- and post-operation ( P <0.05); but no significant difference between 1 week after operation and last follow-up ( P >0.05). All the osteotomies and bone grafts fused well and no complications of loosening and breakage of internal fixator occurred during the follow-up., Conclusion: In the posterior osteotomy for correction of severe kyphosis secondary to ankylosing spondylitis, the self-designed adjustable operation frame is convenient for the patient to be placed in prone position. It is safe, feasible, and effective to perform osteotomy correction with the aid of the self-designed adjustable operation frame.- Published
- 2020
- Full Text
- View/download PDF
481. The synthetic progestin norethindrone causes thyroid endocrine disruption in adult zebrafish.
- Author
-
Liang YQ, Xu W, Liang X, Jing Z, Pan CG, and Tian F
- Subjects
- Animals, Gene Expression Regulation, Larva growth & development, Larva metabolism, Zebrafish Proteins genetics, Contraceptives, Oral, Hormonal toxicity, Endocrine Disruptors toxicity, Larva drug effects, Norethindrone toxicity, Thyroid Hormones metabolism, Transcriptome drug effects, Zebrafish physiology, Zebrafish Proteins metabolism
- Abstract
Synthetic progestin norethindrone (NET) widely used in oral contraceptives, hormonal therapy and livestock farming has been detected in various aquatic ecosystems. Recent studies have shown that NET can cause thyroid endocrine disruption in amphibians. However, studies are still lacking on thyroid axis of fish. In the present study, we investigated thyroid hormone levels (T3 and T4) and transcriptional patterns of 15 genes of the hypothalamic-pituitary-thyroid axis (HPT axis) in adult zebrafish that were exposed to solvent control and three measured concentrations of NET (7, 84 and 810 ng/L) for 90 days. The results indicated that NET significantly lowered T3 and T4 levels in both female and male zebrafish. Transcriptional expression profiles of some of the HPT-axis related genes were disrupted. Specifically, the expression levels of tshb and pax8 have increased significantly while dio2 and ugt1ab have decreased in females. In male, however, tshb expression levels were increased while ttr, ugt1ab, thra and thrb were decreased. The overall results demonstrate that NET disrupts thyroid endocrine system by interfering at multiple sites along HPT axis in adult zebrafish., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)
- Published
- 2020
- Full Text
- View/download PDF
482. Exosomal MicroRNA-126 from RIPC Serum Is Involved in Hypoxia Tolerance in SH-SY5Y Cells by Downregulating DNMT3B.
- Author
-
Cui J, Liu N, Chang Z, Gao Y, Bao M, Xie Y, Xu W, Liu X, Jiang S, Liu Y, Shi R, Xie W, Jia X, Shi J, Ren C, Gong K, Zhang C, Bade R, Shao G, and Ji X
- Abstract
Ischemic tolerance in the brain can be induced by transient limb ischemia, and this phenomenon is termed remote ischemic preconditioning (RIPC). It still remains elusive how this transfer of tolerance occurs. Exosomes can cross the blood-brain barrier, and some molecules may transfer neuroprotective signals from the periphery to the brain. Serum miRNA-126 is associated with ischemic stroke, and exosomal miRNA-126 has shown protective effects against acute myocardial infarction. Therefore, this study aims to explore whether exosomal miRNA-126 from RIPC serum can play a similar neuroprotective role. Exosomes were isolated from the venous serum of four healthy young male subjects, both before and after RIPC. Exosomal miRNA-126 was measured by real-time PCR. The miRNA-126 target sequence was predicted by bioinformatics software. SH-SY5Y neuronal cells were incubated with exosomes, and the cell cycle was analyzed by flow cytometry. The expression and activity of DNA methyltransferase (DNMT) 3B, a potential target gene of miRNA-126, were examined in SH-SY5Y cells. The cell viability of SH-SY5Y cells exposed to oxygen-glucose deprivation (OGD) was also investigated. To confirm the association between miRNA-126 and DNMT3B, we overexpressed miRNA-126 in SH-SY5Y cells using lentiviral transfection. miRNA-126 expression was upregulated in RIPC exosomes, and bioinformatics prediction showed that miRNA-126 could bind with DNMT3B. DNMT levels and DNMT3B activity were downregulated in SH-SY5Y cells incubated with RIPC exosomes. After overexpression of miRNA-126 in SH-SY5Y cells, global methylation levels and DNMT3B gene expression were downregulated in these cells, consistent with the bioinformatics predictions. RIPC exosomes can affect the cell cycle and increase OGD tolerance in SH-SY5Y cells. RIPC seems to have neuroprotective effects by downregulating the expression of DNMTs in neural cells through the upregulation of serum exosomal miRNA-126., (Copyright © 2020 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2020
- Full Text
- View/download PDF
483. Indications Selection for Surgeons Training in the Translaminar Percutaneous Endoscopic Discectomy Based on Finite Element Analysis.
- Author
-
Li J, Xu W, Jiang Q, Xi Z, Zhang X, Wang N, Xie L, and Liu Y
- Subjects
- Biomechanical Phenomena, Computer Simulation, Humans, Intervertebral Disc Degeneration physiopathology, Intervertebral Disc Degeneration surgery, Intervertebral Disc Displacement physiopathology, Intervertebral Disc Displacement surgery, Magnetic Resonance Imaging, Osteotomy, Pressure, Range of Motion, Articular, Reproducibility of Results, Risk, Stress, Mechanical, Diskectomy, Percutaneous education, Endoscopy education, Finite Element Analysis, Surgeons education
- Abstract
Background: Translaminar percutaneous endoscopic discectomy (PED) was used widely in the treatment of lumbar disc herniation (LDH), especially for the training of novice surgeons. A larger range of osteotomy was a suitable method to get enough operation space and reduce intraoperative risks. But osteotomy, especially facetectomy, may be associated with the biomechanical deterioration and resulting adjacent segment diseases (ASD). Hence, the objects of this study were to investigate whether different levels of surgical experience in performing different ranges of osteotomy (especially facetectomy) affected the risk for ASD and to identify the safe indications for the training of PED novice surgeons. Study Design . In this study, a three-dimensional lumbosacral model was constructed and validated. Corresponding translaminar PED models with different ranges of osteotomy for armpit, periradicular, and shoulder types of LDH were constructed. The von Mises stress on the endplates, the shear stress on the annulus, the intradiscal pressure, and the range of motion (ROM) in the L3-L4 segment disc were computed., Results: Computational results in our well-validated model indicated that large ranges of osteotomy led to deterioration in most of the biomechanical indicators, and this trend was most significant in the shoulder-type LDH model., Conclusions: To ensure the appropriateness of the surgical prognosis, armpit and periradicular types of LDH can be seen as suitable indications for the training of novice PED surgeons, and shoulder-type LDH should be excluded from such indications until novices can perform PED within a relatively small range of osteotomy. Mini Abstract . Based on biomechanical variations in our finite element analysis, armpit and periradicular types of LDH can be seen as suitable indications for the training of novice PED surgeons, and shoulder-type LDH should be excluded until novices can perform PED within a relatively small range of osteotomy., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2020 Jingchi Li et al.)
- Published
- 2020
- Full Text
- View/download PDF
484. Metabolic engineering Saccharomyces cerevisiae for de novo production of the sesquiterpenoid (+)-nootkatone.
- Author
-
Meng X, Liu H, Xu W, Zhang W, Wang Z, and Liu W
- Subjects
- Alkyl and Aryl Transferases metabolism, Cytochrome P-450 Enzyme System metabolism, Saccharomyces cerevisiae growth & development, Short Chain Dehydrogenase-Reductases metabolism, Biotechnology methods, Metabolic Engineering, Plant Proteins metabolism, Polycyclic Sesquiterpenes metabolism, Saccharomyces cerevisiae metabolism
- Abstract
Background: (+)-Nootkatone is a highly valued sesquiterpenoid compound, exhibiting a typical grapefruit aroma and various desired biological activities for use as aromatics and pharmaceuticals. The high commercial demand of (+)-nootkatone is predominately met by chemical synthesis, which entails the use of environmentally harmful reagents. Efficient synthesis of (+)-nootkatone via biotechnological approaches is thus urgently needed to satisfy its industrial demand. However, there are only a limited number of studies that report the de novo synthesis of (+)-nootkatone from simple carbon sources in microbial cell factories, and with relatively low yield., Results: As the direct precursor of (+)-nootkatone biosynthesis, (+)-valencene was first produced in large quantities in Saccharomyces cerevisiae by overexpressing (+)-valencene synthase CnVS of Callitropsis nootkatensis in combination with various mevalonate pathway (MVA) engineering strategies, including the expression of CnVS and farnesyl diphosphate synthase (ERG20) as a fused protein, overexpression of a truncated form of the rate-limiting enzyme 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase (tHMG1), and downregulating the squalene synthase enzyme (ERG9). These approaches altogether brought the production of (+)-valencene to 217.95 mg/L. Secondly, we addressed the (+)-valencene oxidation by overexpressing the Hyoscyamus muticus premnaspirodiene oxygenase (HPO) variant (V482I/A484I) and cytochrome P450 reductase (ATR1) from Arabidopsis thaliana. However, (+)-valencene was predominantly oxidized to β-nootkatol and only minor amounts of (+)-nootkatone (9.66 mg/L) were produced. We further tackled the oxidation of β-nootkatol to (+)-nootkatone by screening various dehydrogenases. Our results showed that the short-chain dehydrogenase/reductase (SDR) superfamily dehydrogenases ZSD1 of Zingiber zerumbet and ABA2 of Citrus sinensis were capable of effectively catalyzing β-nootkatol oxidation to (+)-nootkatone. The yield of (+)-nootkatone increased to 59.78 mg/L and 53.48 mg/L by additional overexpression of ZSD1 and ABA2, respectively., Conclusion: We successfully constructed the (+)-nootaktone biosynthesis pathway in S. cerevisiae by overexpressing the (+)-valencene synthase CnVS, cytochrome P450 monooxygenase HPO, and SDR family dehydrogenases combined with the MVA pathway engineering, providing a solid basis for the whole-cell production of (+)-nootkatone. The two effective SDR family dehydrogenases tested in this study will serve as valuable enzymatic tools in further optimizing (+)-nootkatone production.
- Published
- 2020
- Full Text
- View/download PDF
485. Expansion of Impervious Surfaces and Their Driving Forces in Highly Urbanized Cities in Kyrgyzstan.
- Author
-
Omurakunova G, Bao A, Xu W, Duulatov E, Jiang L, Cai P, Abdullaev F, Nzabarinda V, Durdiev K, and Baiseitova M
- Subjects
- Cities statistics & numerical data, Conservation of Natural Resources, Environmental Monitoring, Kyrgyzstan, Population Growth, Satellite Imagery, Urbanization trends
- Abstract
The expansion of urban areas due to population increase and economic expansion creates demand and depletes natural resources, thereby causing land use changes in the main cities. This study focuses on land cover datasets to characterize impervious surface (urban area) expansion in select cities from 1993 to 2017, using supervised classification maximum likelihood techniques and by quantifying impervious surfaces. The results indicate an increasing trend in the impervious surface area by 35% in Bishkek, 75% in Osh, and 15% in Jalal-Abad. The overall accuracy (OA) for the image classification of two different datasets for the three cities was between 82% and 93%, and the kappa coefficients (KCs) were approximately 77% and 91%. The Landsat images with other supplementary data showed positive urban growth in all of the cities. The GDP, industrial growth, and urban population growth were driving factors of impervious surface sprawl in these cities from 1993 to 2017.Landscape Expansion Index (LEI) results also provided good evidence for the change of impervious surfaces during the study period. The results emphasize the idea of applying future planning and sustainable urban development procedures for sustainable use of natural resources and their management, which will increase life quality in urban areas and environments.
- Published
- 2020
- Full Text
- View/download PDF
486. Exploring Variability in Landscape Ecological Risk and Quantifying Its Driving Factors in the Amu Darya Delta.
- Author
-
Yu T, Bao A, Xu W, Guo H, Jiang L, Zheng G, Yuan Y, and Nzabarinda V
- Subjects
- China, Conservation of Natural Resources, Humans, Models, Theoretical, Population Density, Spatial Regression, Temperature, Urban Population, Ecosystem, Environmental Monitoring methods
- Abstract
Examining the drivers of landscape ecological risk can provide scientific information for planning and landscape optimization. The landscapes of the Amu Darya Delta (ADD) have recently undergone great changes, leading to increases in landscape ecological risks. However, the relationships between landscape ecological risk and its driving factors are poorly understood. In this study, the ADD was selected to construct landscape ecological risk index (ERI) values for 2000 and 2015. Based on a geographically weighted regression (GWR) model, the relationship between each of the normalized difference vegetation index (NDVI), land surface temperature (LST), digital elevation model (DEM), crop yield, population density (POP), and road density and the spatiotemporal variation in ERI were explored. The results showed that the ERI decreased from the periphery of the ADD to the centre and that high-risk areas were distributed in the ADD's downstream region, with the total area of high-risk areas increasing by 86.55% from 2000 to 2015. The ERI was spatially correlated with Moran's I in 2000 and 2015, with correlation of 0.67 and 0.72, respectively. The GWR model indicated that in most ADD areas, the NDVI had a negative impact on the ERI, whereas LST and DEM had positive impacts on the ERI. Crop yield, road density and POP were positively correlated with the ERI in the central region of the ADD, at road nodes and in densely populated urban areas, respectively. Based on the findings of this study, we suggest that the ecological constraints of the aforementioned factors should be considered in the process of delta development and protection.
- Published
- 2019
- Full Text
- View/download PDF
487. [Treatment of osteoporotic vertebral fracture combined with moderate to severe spinal kyphosis by transintervertebral release, bone impaction grafting, and posterior column compressed-closing].
- Author
-
Xu W, Yu H, Liang C, Zhai Y, Cui X, Wang W, and Zhang W
- Subjects
- Aged, Female, Fracture Fixation, Internal, Humans, Lumbar Vertebrae, Male, Middle Aged, Quality of Life, Retrospective Studies, Treatment Outcome, Kyphosis, Spinal Fractures
- Abstract
Objective: To explore the safety and preliminary effectiveness of transintervertebral release, bone impaction grafting, and posterior column compressed-closing in the treatment of osteoporotic vertebral fracture combined with moderate to severe spinal kyphosis., Methods: The clinical data of 21 elderly patients with osteoporotic vertebral fracture combined with moderate to severe spinal kyphosis were retrospectively analyzed between March 2016 and November 2017. There were 1 male and 20 females, aged 55-75 years, with an average of 64.8 years. The disease duration was 8-24 months, with an average of 13.1 months. The bone density T value ranged from -3.4 to -2.1, with an average of -2.3. Lesion segments: T
11 in 2 cases, T12 in 6 cases, L1 in 8 cases, L2 in 1 case, T11, 12 in 1 case, T12 , L1 in 2 cases, and T12 , L2 in 1 case. Preoperative neurological function was classified according to the American Spinal Injury Association (ASIA): 5 cases of grade D and 16 cases of grade E. All patients underwent transintervertebral release, bone impaction grafting, and posterior column compressed-closing. The effectiveness was evaluated by visual analogue scale (VAS) score and Oswestry dysfunction index (ODI) score before operation, at 3 months after operation, and at last follow-up. The neurological function was assessed by ASIA at last follow-up. Local kyphosis Cobb angle (LKCA), thoracic kyphosis (TK), lumbar lordosis (LL), and sagittal vertebral axis (SVA) were measured on the X-ray films of the full-length lateral spine of the patient before operation, at 1 week after operation, and at last follow-up., Results: No complication such as fracture of internal fixator or nerve injury occurred. LKCA, TK, and SVA were significantly improved at 1 week after operation and at last follow-up ( P <0.05). There was no significant difference between at 1 week after operation and at last follow-up ( P >0.05). There was no significant difference in LL before and after operation ( F =3.013, P =0.057). The VAS and ODI scores were significantly improved at 3 months after operation and at last follow-up, and further improved at last follow-up when compared with the scores at 3 months after operation, showing significant differences between time points ( P <0.05). Five patients with ASIA grade D neurological function recovered to grade E at 6 months after operation., Conclusion: Transintervertebral release, bone impaction grafting, and posterior column compressed-closing for treating osteoporotic vertebral fracture combined with moderate to severe spinal kyphosis has definite effectiveness, strong orthopaedic ability, and minimal trauma, which can effectively restore the sagittal balance of the spine, alleviate pain, and improve the patients' quality of life.- Published
- 2019
- Full Text
- View/download PDF
488. Biomechanical role of osteoporosis affects the incidence of adjacent segment disease after percutaneous transforaminal endoscopic discectomy.
- Author
-
Li J, Xu W, Zhang X, Xi Z, and Xie L
- Subjects
- Biomechanical Phenomena physiology, Diskectomy, Percutaneous trends, Humans, Incidence, Intervertebral Disc Degeneration epidemiology, Intervertebral Disc Degeneration surgery, Intervertebral Disc Displacement epidemiology, Intervertebral Disc Displacement surgery, Lumbar Vertebrae surgery, Osteoporosis epidemiology, Osteoporosis surgery, Postoperative Complications epidemiology, Tomography, X-Ray Computed trends, Diskectomy, Percutaneous adverse effects, Imaging, Three-Dimensional trends, Intervertebral Disc Degeneration diagnostic imaging, Intervertebral Disc Displacement diagnostic imaging, Lumbar Vertebrae diagnostic imaging, Osteoporosis diagnostic imaging, Postoperative Complications diagnostic imaging
- Abstract
Study Design: Variation in the biomechanical characteristics of intervertebral discs adjacent to the segment disc after undergoing percutaneous transforaminal endoscopic discectomy (PTED) in models with normal and abnormal bone mineral density (BMD) was estimated using the finite element method., Objective: The study investigated the change in the incidence of adjacent segment disease (ASD) after PTED in patients without and with osteoporosis., Backgrounds: PTED has been widely used for treating lumbar disc herniation (LDH); changes in BMD will affect biomechanical characteristics, possibly leading to changes in the incidence of ASD after PTED. However, this issue remains largely unclear., Methods: A non-linear, lumbosacral finite element model was reconstructed based on imaging data and validated using compared values computed by the current model from published and well-validated, in vitro biomechanical experiment studies. Corresponding PTED models with normal and abnormal BMDs were also reconstructed. Shear and von Mises stresses on the annulus fibrosis, the von Mises stress on the endplates in L5-S1 segment discs, and the total deformation of current lumbosacral models were computed in different body positions by changing loading conditions, including flexion, extension, left and right lateral bending, and axial rotation., Results: In most loading conditions, biomechanical characteristics of the lumbosacral segment discs with normal BMDs after PTED slightly increased. However, in the PTED model with osteoporosis, most of the biomechanical characteristics dramatically increased., Conclusion: Osteoporosis leads to the deterioration of biomechanical characteristics in the adjacent segment disc after PTED; this variation may also result in an increase in the incidence of ASD. However, further studies on the interactions between pathological changes are warranted.
- Published
- 2019
- Full Text
- View/download PDF
489. Functional characterization of the upstream components of the Hog1-like kinase cascade in hyperosmotic and carbon sensing in Trichoderma reesei .
- Author
-
Wang Z, An N, Xu W, Zhang W, Meng X, Chen G, and Liu W
- Abstract
Background: Trichoderma reesei holds a high capacity for protein secretion and represents the most important cellulase producer in industry. However, the external signal sensing and intracellular signal transduction during cellulose induction remain unclear. As one of the most pervasive signal transduction pathways in all eukaryotic species, the mitogen-activated protein kinase (MAPK) pathway and its upstream sensing and signaling components are involved in various physiological processes including stress and nutrient sensing. Particularly, the Hog1-type MAPK Tmk3 has been reported to be involved in the cellulase production in T. reesei ., Results: Here we established the physiological role of two upstream regulatory branches, the Sho1 branch and the Sln1 branch, of the Hog1-type Tmk3 pathway in T. reesei . Deletion of Trste20 of the Sho1 branch or repression of Trypd1 of the Sln1 branch reduced the resistance to high salt stress, whereas TrSho1 showed an opposing effect to that of TrSte20 and the identified TrSln1 seemed to be dispensable in the osmotic regulation. The Sho1 and Sln1 branches also participated in the cell wall integrity maintenance and other stress responses (i.e. oxidative and thermo stresses). Notably, TrSho1 and TrSte20 of the Sho1 branch and TrYpd1 of the Sln1 branch were shown to be differentially involved in the cellulase production of T. reesei . Repression of Trypd1 hardly affected cellulase induction, whereas overexpression of Trypd1 resulted in the reduced production of cellulases. Contrary to the case of Trypd1 , repression of Trsho1 or deletion of Trste20 significantly reduced the transcription of cellulase genes., Conclusions: TrSho1 and TrSte20 of the Sho1 branch and TrYpd1 of the Sln1 branch are all involved in general stress responses including hyperosmotic regulation and cell wall integrity maintenance. Moreover, our study revealed that the Sho1 and Sln1 osmosensing pathways are differentially involved in the regulation of cellulase production in T. reesei . The Sho1 branch positively regulated the production of cellulases and the transcription of cellulase genes while TrYpd1 of the Sln1 branch negatively controlled the cellulase production, supporting the crosstalks of osmosensing and nutrient sensing.
- Published
- 2018
- Full Text
- View/download PDF
490. [Soil properties under shrubs in arid area of oasis-desert transition belt].
- Author
-
Xu W, Luo G, and Chen X
- Subjects
- Ecosystem, Environment, Tamaricaceae growth & development, Desert Climate, Nitrogen analysis, Potassium analysis, Soil analysis, Trees growth & development
- Abstract
In arid and semi-arid areas with sparse vegetation cover, the spatial pattern of surface soil had a definite effect on soil salinity and nutrient flow, which is of highly importance for understanding the processes of land cover change. In this paper, a total of 3 shrub types and 2 soil sampling depths (0-20 and 20-40 cm) in the arid area of oasis-desert transition belt were selected to assess the spatial heterogeneity of soil resources under shrubs. The results showed that different types of shrub had no significant effect on the particle size distribution of soil which was mainly composed of sand and silt, but significant cluster effect was observed under Tamarix ramosissima + bare land shrub. Soils under shrub canopy had significantly higher contents of organic matter, total N and available K, compared to those in open spaces, and presented obvious "fertile island" phenomenon. Shrub types had significant effects on soil salinity, and different cluster effect existed in soils under different shrubs. The heterogeneity of soil resources resulted from a large number of factors, including climate, soil environment, height and extent of shrub canopy, stemflow, existance of other ground cover plants, and so on, many of which were mutually interactive.
- Published
- 2006
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.