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1.
Acta Pharmacol Sin ; 2020 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-32424239

RESUMO

Mitsugumin 53 (MG53) is a tripartite motif family protein that has been reported to attenuate injury via membrane repair in different organs. Contrast-induced acute kidney injury (CI-AKI) is a common complication caused by the administration of iodinated contrast media (CM). While the cytotoxicity induced by CM leading to tubular cell death may be initiated by cell membrane damage, we wondered whether MG53 alleviates CI-AKI. This study was designed to investigate the effect of MG53 on CI-AKI and the underlying mechanism. A rat model of CI-AKI was established, and CI-AKI induced the translocation of MG53 from serum to injury sites on the renal proximal tubular (RPT) epithelia, as illustrated by immunoblot analysis and immunohistochemical staining. Moreover, pretreatment of rats with recombinant human MG53 protein (rhMG53, 2 mg/mL) alleviated iopromide-induced injury in the kidney, which was determined by measuring serum creatinine, blood urea nitrogen and renal histological changes. In vitro studies demonstrated that exposure of RPT cells to iopromide (20, 40, and 80 mg/mL) caused cell membrane injury and cell death, which were attenuated by rhMG53 (10 and 50 µg/mL). Mechanistically, MG53 translocated to the injury site on RPT cells and bound to phosphatidylserine to protect RPT cells from iopromide-induced injury. In conclusion, MG53 protects against CI-AKI through cell membrane repair and reducing cell apoptosis; therefore, rhMG53 might be a potential effective means to treat or prevent CI-AKI.

2.
Can J Cardiol ; 2020 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-32428616

RESUMO

BACKGROUND: Atherosclerosis-related cardiovascular diseases are among the leading causes of mortality worldwide. Uptake of modified lipoproteins by monocyte-derived macrophages leads to the formation of foam cells, which by secreting pro-inflammatory cytokines accelerate plaque development. Sorting Nexin 10 (SNX10) plays a critical role in the regulation of macrophage functions as well as in the lipid metabolism. This study aims to explore the precise effects and the underlying molecular mechanisms of SNX10 mediated processes in atherosclerotic diseases. METHODS: SNX10 knockout mice were generated and bone marrow-derived macrophages (BMDMs) were studied in vitro. Mice were crossed with apolipoprotein E-deficient (ApoE-/-) mice and atherogenesis was monitored for 16 weeks. RESULTS: Expression of SNX10 was increased in atherosclerotic plaques from both humans and ApoE-/- mice. SNX10 deficiency decreased foam cell abundance and alleviated atherosclerotic plaque progression in ApoE-/- mice. In addition, high fat, high cholesterol diet fed ApoE-/- mice contained more Ly6ChiCX3CR1lo monocytes than ApoE-/- SNX10-/- (DKO) littermates. ApoE-/- mice showed a higher level of inflammatory macrophages infiltrating into atherosclerotic lesions. SNX10 deficiency reduced the interactions between CD36 and Lyn, thus inhibiting CD36-mediated lipoprotein uptake and foam cell formation. CONCLUSIONS: Our findings demonstrate CD36-Lyn dependent non-redundant atherogenic role for SNX10 in diet-induced atherogenesis. We propose SNX10 as a potential therapeutic target for the prevention and treatment of atherosclerosis.

3.
Mov Disord ; 2020 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-32392383

RESUMO

BACKGROUND: Paroxysmal kinesigenic dyskinesia is a spectrum of involuntary dyskinetic disorders with high clinical and genetic heterogeneity. Mutations in proline-rich transmembrane protein 2 have been identified as the major pathogenic factor. OBJECTIVES: We analyzed 600 paroxysmal kinesigenic dyskinesia patients nationwide who were identified by the China Paroxysmal Dyskinesia Collaborative Group to summarize the clinical phenotypes and genetic features of paroxysmal kinesigenic dyskinesia in China and to provide new thoughts on diagnosis and therapy. METHODS: The China Paroxysmal Dyskinesia Collaborative Group was composed of departments of neurology from 22 hospitals. Clinical manifestations and proline-rich transmembrane protein 2 screening results were recorded using unified paroxysmal kinesigenic dyskinesia registration forms. Genotype-phenotype correlation analyses were conducted in patients with and without proline-rich transmembrane protein 2 mutations. High-knee exercises were applied in partial patients as a new diagnostic test to induce attacks. RESULTS: Kinesigenic triggers, male predilection, dystonic attacks, aura, complicated forms of paroxysmal kinesigenic dyskinesia, clustering in patients with family history, and dramatic responses to antiepileptic treatment were the prominent features in this multicenter study. Clinical analysis showed that proline-rich transmembrane protein 2 mutation carriers were prone to present at a younger age and have longer attack duration, bilateral limb involvement, choreic attacks, a complicated form of paroxysmal kinesigenic dyskinesia, family history, and more forms of dyskinesia. The new high-knee-exercise test efficiently induced attacks and could assist in diagnosis. CONCLUSIONS: We propose recommendations regarding diagnostic criteria for paroxysmal kinesigenic dyskinesia based on this large clinical study of paroxysmal kinesigenic dyskinesia. The findings offered some new insights into the diagnosis and treatment of paroxysmal kinesigenic dyskinesia and might help in building standardized paroxysmal kinesigenic dyskinesia clinical evaluations and therapies. © 2020 International Parkinson and Movement Disorder Society.

4.
Prostate ; 80(10): 753-763, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32421868

RESUMO

BACKGROUND: Although thrombospondins 4 (THBS4) participates in controlling the biology of prostate cancer (PCa), the mechanism underlying this regulation remains unknown. Hence, this study aims to identify the regulatory effects of THBS4 on the PCa stem cell-like properties and the potential mechanism associated with the phosphatidylinositol 3'-kinase (PI3K)/protein kinase B (Akt) pathway. METHODS: PCa stem cells were sorted and identified using flow cytometry and THBS4 expression in the identified PCa stem cells was measured using Western blot assay. THBS4 was overexpressed or silenced in PCa stem cells, following which, self-renewal, proliferation, cell cycle distribution, and apoptosis of PCa stem cells were assessed as well as tumorigenicity in vivo was evaluated. PI3K/Akt pathway inhibitor was applied to identify its involvement in the regulatory roles of THBS4 in PCa stem cells. RESULTS: THBS4 was expressed at a higher level in PCa stem cells than in PCa cells. The overexpression of THBS4 promoted the self-renewal and proliferation, curbed the apoptosis of PCa stem cells, and enhanced the in vivo tumorigenicity, which was achieved by activating the PI3K/Akt pathway. On the contrary, short-hairpin RNA-mediated silencing of THBS4 exhibited suppressive effects on those cancer stem cell (CSC)-like properties and promotive effects on their apoptosis. CONCLUSION: THBS4 silencing can impede the CSC-like properties in PCa via blockade of the PI3K/Akt pathway, which provides patients with PCa a new therapeutic target.

5.
BMC Plant Biol ; 20(1): 220, 2020 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-32423383

RESUMO

BACKGROUND: Nitrogen is an essential element for sugarcane growth and development and is generally applied in the form of urea often much more than at recommended rates, causing serious soil degradation, particularly soil acidification, as well as groundwater and air pollution. In spite of the importance of nitrogen for plant growth, fewer reports are available to understand the application and biological role of N2 fixing bacteria to improve N2 nutrition in the sugarcane plant. RESULTS: In this study, a total of 350 different bacterial strains were isolated from rhizospheric soil samples of the sugarcane plants. Out of these, 22 isolates were selected based on plant growth promotion traits, biocontrol, and nitrogenase activity. The presence and activity of the nifH gene and the ability of nitrogen-fixation proved that all 22 selected strains have the ability to fix nitrogen. These strains were used to perform 16S rRNA and rpoB genes for their identification. The resulted amplicons were sequenced and phylogenetic analysis was constructed. Among the screened strains for nitrogen fixation, CY5 (Bacillus megaterium) and CA1 (Bacillus mycoides) were the most prominent. These two strains were examined for functional diversity using Biolog phenotyping, which confirmed the consumption of diverse carbon and nitrogen sources and tolerance to low pH and osmotic stress. The inoculated bacterial strains colonized the sugarcane rhizosphere successfully and were mostly located in root and leaf. The expression of the nifH gene in both sugarcane varieties (GT11 and GXB9) inoculated with CY5 and CA1 was confirmed. The gene expression studies showed enhanced expression of genes of various enzymes such as catalase, phenylalanine-ammonia-lyase, superoxide dismutase, chitinase and glucanase in bacterial-inoculated sugarcane plants. CONCLUSION: The results showed that a substantial number of Bacillus isolates have N-fixation and biocontrol property against two sugarcane pathogens Sporisorium scitamineum and Ceratocystis paradoxa. The increased activity of genes controlling free radical metabolism may at least in part accounts for the increased tolerance to pathogens. Nitrogen-fixation was confirmed in sugarcane inoculated with B. megaterium and B. mycoides strains using N-balance and 15N2 isotope dilution in different plant parts of sugarcane. This is the first report of Bacillus mycoides as a nitrogen-fixing rhizobacterium in sugarcane.

6.
Immunol Invest ; : 1-18, 2020 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-32397769

RESUMO

Background: The role of T cell Ig and ITIM domain (TIGIT) and programmed cell death-1 (PD-1) in colorectal cancer (CRC) with mismatch repair deficiency is unknown.Methods: This was a study of 60 CRC patients with mismatch repair deficiency and 30 healthy controls between June 2015 and October 2015.Results: The expression of Foxp3, PD-1, and TIGIT was higher in cancer tissues compared with adjacent mucosa (all P < .05). Patients with advanced TNM stage had a significantly higher expression of TIGIT (P = .025) and PD-1 (P = .020) than patients with early-stage CRC. The disease-free survival (DFS) of patients with high TIGIT (HR = 3.96, 95%CI: 1.34-11.69, P = .013) or PD-1 (HR = 214.8, 95%CI: 49.88-925.2, P < .001) expression were better. The overall survival (OS) of the patients with CRC and high expression of PD-1 was worse than those with low expression (HR = 4.01, 95%CI:1.26-12.69, P = .019).Conclusion: TIGIT and PD-1 are upregulated in CRC with mismatch repair deficiency and associated with TNM stage and DFS.

7.
Artigo em Inglês | MEDLINE | ID: mdl-32401038

RESUMO

Background: The molecular mechanisms underlying gastric cancer (GC) progression are unclear. The authors examined key genes associated with the prognosis and tumor-infiltrating immune cells in patients with GC. Materials and Methods: Gene expression omnibus (GEO) was used to filter and obtain GC-related differentially expressed genes (DEGs). The molecular functions, biological processes, and cellular components of the DEGs were subjected to enrichment analysis. Protein-protein interaction networks of proteins encoded by the DEGs were analyzed using STRING. The authors also identified hub genes of GC, as well as their expression levels in GC and their relationship with patient prognosis. The relationship between hub genes and tumor-infiltrating immune cells was analyzed by Tumor IMmune Estimation Resource. Results: Six GEO datasets were included in this study, and 265 DEGs were identified. These DEGs were enriched in different signaling pathways and had different biological functions. Six hub genes were potentially significantly related to the molecular mechanisms of GC (TOP2A, FN1, SPARC, COL3A1, COL1A1, and TIMP1). These genes are potential markers of prognosis. Five hub genes were significantly positively correlated with the number of macrophages, neutrophils, and dendritic cells. Conclusions: The authors provide a theoretical basis for exploring the molecular regulation mechanism underlying GC and identifying therapeutic targets.

8.
Artigo em Inglês | MEDLINE | ID: mdl-32417918

RESUMO

Medulloblastomas (MBs) are currently divided into 4 molecular subgroups: WNT, SHH, Group 3, and Group 4. Among them, Group 3 MB has the worst prognosis, and 40%-50% of Group 3 cases are already metastatic at the time of diagnosis. Emerging evidence indicates that exosomes drive tumor invasion, but very little is known about exosomes in MBs. In this study, we initially discovered that exosomes isolated from Group 3 MB cell lines altered in vitro behaviors of a less invasive SHH MB cell line and yielded a much more aggressive phenotype. RNA-sequencing analysis revealed 7 exosomal miRNAs with markedly different expression levels between the SHH and Group 3 MB cell lines. They were all predicted to be related to the Ras/MAPK pathway according to the Kyoto Encyclopedia of Genes and Genomes data analysis. Increased expression of miR-181a-5p, miR-125b-5p, and let-7b-5p was further confirmed in Group 3 MB cells with real-time PCR and was shown to increase in vitro invasion and migratory abilities of tumor cells through the activation of ERK in Ras/MAPK pathway. Collectively, our findings suggest that exosomal miRNAs have a critical role in MB progression in vitro and might serve as diagnostic biomarkers and therapeutic targets.

9.
J Sci Food Agric ; 2020 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-32418235

RESUMO

BACKGROUND: Irradiation can cause lipid oxidation of fish. This study aimed to examine the effect of radiation (method, dose, and dose rate) on the acid value (AV), peroxide value (PV), thiobarbituric acid reactive substances (TBARS) content, and fatty acid profile of fresh and freeze-dried largemouth bass fleshes. RESULTS: The AV, PV and TBARS presented dose dependent increase in fish meat for both cobalt-60 (60 Co) and electron beam (EB) irradiation. With a 6 kGy of radiation, all measured indices in 60 Co group were significantly higher than those in EB group (P<0.05 or P<0.01). With a 3 kGy of radiation, the AV, PV and TBARS in 200 Gy/min dose rate group were significantly lower than those in 2 Gy/min and 80 Gy/min groups (P<0.05). After 60 Co irradiation, the AV, PV and TBARS in most of fresh samples were significantly higher than those in freeze-dried samples (P<0.01). And 60 Co radiation decreased the unsaturated fatty acid (UFA) content in fresh samples and increased the UFA content in freeze-dried samples. Our study indicated that 60 Co irradiation, particularly at a low dose rate, accelerated lipid oxidation in fish meat. A large amount of muscle moisture enhances the amount of UFA loss in fish meat during 60 Co irradiation. CONCLUSION: Low dose (3 kGy) of EB irradiation, high dose rate (200 Gy/min) of 60 Co irradiation or freeze-drying treatment can alleviate the lipid oxidation of largemouth bass meat. This article is protected by copyright. All rights reserved.

10.
Artigo em Inglês | MEDLINE | ID: mdl-32386798

RESUMO

INTRODUCTION: Advanced fibrosis in nonalcoholic fatty liver disease (NAFLD) is associated with a poor prognosis. The genetic factors contributing to fibrosis in NAFLD have been described. However, the genetic mechanism and hub genes of advanced fibrosis have not been elucidated to date. In this study, we performed a weighted gene coexpression network analysis (WGCNA) to identify the hub genes related to advanced fibrosis in NAFLD. MATERIALS AND METHODS: The datasets GSE89632 and GSE31803 of NAFLD patients were selected from the Gene Expression Omnibus (GEO) database of NCBI and analyzed by WGCNA. The hub genes were selected in the GSE31803 dataset and verified in the GSE31803 dataset. Gene Ontology (GO) term enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of the dataset were also performed. RESULTS: The gene LUM was identified as the hub gene in the datasets GSE89632 and GSE31803 according to three different algorithms (gene significance and module membership, the pathways of the genes, and protein expressed by the genes). The functional enrichment analysis shows that the identified module is related to the extracellular matrix, regulation of cell proliferation, and the inflammatory response. The metabolic pathway analysis identified metabolic pathways and focal adhesion as the most important pathways. CONCLUSION: By a variety of methods, LUM was identified as the hub gene of advanced fibrosis in patients with NAFLD. Therefore, further research on the LUM gene is warranted.

11.
Medicine (Baltimore) ; 99(20): e20289, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32443375

RESUMO

BACKGROUND: Recent studies have suggested that propofol combined butorphanol (PB) has anesthetic effect in laparoscopic surgery (LS) for ectopic pregnancy (EP). But investigations of its potential effects are inconsistent. We will explore the current literature examining PB in LS for EP. METHODS: We will perform a comprehensive search from MEDLINE, Embase, Cochrane Library, PsycINFO, Global Health, Web of Science, Allied and Complementary Medicine Database, and China National Knowledge Infrastructure from inception to the present. Other literatures, such as conference abstracts, references to the relevant reviews will also be checked. Two authors will check the titles, abstracts, and full texts independently. They will also independently carry out data collection and study quality assessment. We will conduct statistical analysis using RevMan 5.3 software. RESULTS: This study will provide accurate results on the anesthetic effect and safety of PB in LS for EP. CONCLUSION: This study will establish high-quality evidence of the anesthetic effect and safety of PB in LS for EP to facilitate the clinical practice and guideline development. STUDY REGISTRATION NUMBER: INPLASY202040044.

12.
Artigo em Inglês | MEDLINE | ID: mdl-32446561

RESUMO

Nasopharyngeal carcinoma (NPC) is relatively sensitive to ionizing radiation, and radiotherapy is the main treatment modality for non-metastatic NPC. Radiation therapy generates overproduction of reactive oxygen species (ROS), which can cause DNA damage and induce apoptosis in tumors, thereby killing the malignant cells. Although dietary antioxidant supplementation reduces oxidative stress and promotes tumor progression, the effects of antioxidants on the NPC cells upon radiation have not been reported. In the present study, we showed that antioxidants (ß-Carotene, NAC, GSH) played an anti-apoptotic role in response to radiation via decreasing ROS production and inhibiting MAPK pathway in NPC cells. Based on that, we conclude that the use of supplemental antioxidants during radiotherapy should be avoided because of the possibility of tumor protection and reduced treatment efficacy.

13.
J Phys Chem A ; 2020 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-32390419

RESUMO

Identification of the geometric structures of silver clusters is of great importance in future nanotechnologies due to their superior properties. Nevertheless, some ground-state structures are still in academic debate, partly because the experiments and theoretical calculations are not performed at the same temperatures. For example, silver clusters usually have compact configurations. However, a combined experimental and theoretical study proposed that the most stable structure of Ag13- had a two-coordinated atom. By using the CALYPSO approach for the global minima search followed by first-principles calculations, we discovered that a more compact trilayer Ag13- cluster was the ground state, in accordance with another three works published recently. In addition, its O2 adsorption structure is also energetically favored. By tracing characteristic bond changes in ab initio molecular dynamics (MD) simulations, we confirmed that, compared with other isomers, this trilayer structure and its O2 adsorption structure also had the highest thermal stability. This work emphasized the thermal stability concept in theoretical calculations, which may be a necessary supplement to explain the experimental observations on cluster science.

14.
Artigo em Inglês | MEDLINE | ID: mdl-32372639

RESUMO

As an important organic intermediate, benzonitrile (BN) is widely involved in organic synthetic chemistry and pharmaceutical and dyestuff industries. However, the exploration of a more efficient and controllable synthesis technique and the corresponding greener catalysts for the synthesis of BN still poses a great challenge. Herein, with multimetallic two-dimensional conductive metal-organic frameworks (2D cMOF) as anodic electrocatalysts, we develop a green, convenient, and highly efficient electrochemical synthesis strategy for BN. Thanks to the intrinsic 2D electrically conductive structure and the optimized the multimetallic coupling catalytic effect, the resulting multimetallic 2D cMOFs exhibit excellent benzylamine (BA) electrooxidation performance. Especially, the trimetallic 2D cMOF (NiCoFe-CAT) requires an ultralow potential of 1.29 V vs reversible hydrogen electrode (RHE) to achieve a 10 mA·cm-2 current density, which indicates the fastest reaction and the most favorable thermodynamic condition. A very high yield (0.058 mmol·mg-1·h-1) and faradic efficiency (∼87%) of benzonitrile are both achieved during the BA electrooxidation reaction at 1.45 V. The reaction mechanism investigations indicated that the various redox mediators of MII/MIII (Ni, Co, Fe) may be regarded as multimetal active species to promote BA conversion. Also, the excellent cycling durability of multimetallic 2D cMOFs further promotes their potential practical applications. These electrocatalytic performances are considered excellent and nearly surpass all other reported Ni-based inorganics or MOF-based electrocatalysts for the electrocatalytic oxidation of benzylamine.

15.
BMC Pediatr ; 20(1): 210, 2020 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-32398036

RESUMO

BACKGROUND: The infrared tympanic thermometer (IRTT) is a popular method for temperature screening in children, but it has been debated for the low accuracy and reproducibility compared with other measurements. This study was aimed to identify and quantify studies reporting the diagnostic accuracy of the new generation IRTT in children and to compare the sensitivity and specificity of IRTT under different cutoffs and give the optimal cutoff. METHODS: Articles were derived from a systematic search in PubMed, Web of Science Core Collection, and Embase, and were assessed for internal validity by the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2). The figure of risk of bias was created by Review Manager 5.3 and data were synthesized by MetaDisc 1.4. RESULTS: Twelve diagnostic studies, involving 4639 pediatric patients, were included. The cut-offs varied from 37.0 °C to 38.0 °C among these studies. The cut-off 37.8 °C was with the highest sROC AUC (0.97) and Youden Index (0.83) and was deemed to be the optimal cutoff. CONCLUSION: The optimal cutoff for infrared tympanic thermometers is 37.8 °C. New Generation Tympanic Thermometry is with high diagnostic accuracy in pediatric patients and can be an alternative for fever screening in children.

16.
Artigo em Inglês | MEDLINE | ID: mdl-32445263

RESUMO

BACKGROUND AND AIMS: Tri-typing of acute-on-chronic liver failure (ACLF), as proposed by the World Gastroenterology Organization (WGO), has not been validated in patients infected with hepatitis B virus (HBV). We aim to compare the three types of ACLF patients in clinic characteristics. METHODS: Hospitalized ACLF patients with chronic hepatitis B from 5 hepatology centers were retrospectively selected and grouped according to the WGO classification. For each group, we investigated laboratory tests, precipitating events, organ failure and clinical outcome. RESULTS: Compared with type-B (n=262, compensated cirrhosis) and type-C (n=129, decompensated cirrhosis) ACLF, type-A patients (n=195, non-cirrhosis) were associated with a younger age, the highest platelet counts, the highest aminotransferase levels and the most active HBV replications. Hepatitis B virus reactivation were more predominant in type-A, while bacterial infections in type-B and type-C ACLF cases. Liver failure (97.4%) and coagulation failure (86.7%) were most common in type-A compared with type-B or type-C ACLF patients. Kidney failure was predominantly identified in type-C subjects (41.9%), and was highest (23/38, 60.5%) in grade-1 ACLF patients. Furthermore, type-C ACLF showed the highest 28-day (65.2%) and 90-day (75.3%) mortalities, compared with type-A (48.7% and 54.4%, respectively) and type-B (48.4% and 62.8% respectively) ACLF cases. Compared with type-A (11.7%) ACLF patients, the increased mortality from 28-day to 90-day was higher in type-B (31.6%) and type-C (37.5%). CONCLUSION: Tri-typing of HBV-related ACLF in accordance with the WGO definition was able to distinguish clinical characteristics, including precipitating events, organ failure, and short-term prognosis in ACLF patients.

17.
Ecol Lett ; 2020 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-32436358

RESUMO

Understanding how biodiversity and interaction networks change across environmental gradients is a major challenge in ecology. We integrated metacommunity and metanetwork perspectives to test species' functional roles in bird-plant frugivory interactions in a fragmented forest landscape in Southwest China, with consequences for seed dispersal. Availability of fruit resources both on and under trees created vertical feeding stratification for frugivorous birds. Bird-plant interactions involving birds feeding only on-the-tree or both on and under-the-tree (shared) had a higher centrality and contributed more to metanetwork organisation than interactions involving birds feeding only under-the-tree. Moreover, bird-plant interactions associated with large-seeded plants disproportionately contributed to metanetwork organisation and centrality. Consequently, on-the-tree and shared birds contributed more to metanetwork organisation whereas under-the-tree birds were more involved in local processes. We would expect that species' roles in the metanetwork will translate into different conservation values for maintaining functioning of seed-dispersal networks.

18.
J Synchrotron Radiat ; 27(Pt 3): 753-761, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32381778

RESUMO

Anaerobic ammonium-oxidizing (anammox) bacteria play a key role in the global nitrogen cycle and in nitrogenous wastewater treatment. The anammox bacteria ultrastructure is unique and distinctly different from that of other prokaryotic cells. The morphological structure of an organism is related to its function; however, research on the ultrastructure of intact anammox bacteria is lacking. In this study, in situ three-dimensional nondestructive ultrastructure imaging of a whole anammox cell was performed using synchrotron soft X-ray tomography (SXT) and the total variation-based simultaneous algebraic reconstruction technique (TV-SART). Statistical and quantitative analyses of the intact anammox bacteria were performed. High soft X-ray absorption composition inside anammoxosome was detected and verified to be relevant to iron-binding protein. On this basis, the shape adaptation of the anammox bacteria response to iron was explored.

19.
Sci Rep ; 10(1): 7198, 2020 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-32350351

RESUMO

Different fertilization regimes can substantially influence soil fungal community composition, yet fewer studies try to control for the effects of nitrogen input. Here, we investigated the impact of fertilization with equal nitrogen upon soil properties and soil fungal diversity and community composition in the North China Plain in a long-term field experiment. Long-term (32 years) fertilization regimes were applied with equal amounts of nitrogen: no chemical fertilizer or organic manure; chemical fertilization only; organic manure fertilization only, and; combination of 1/2 chemical fertilizer and 1/2 organic manure. Then we investigated the influence of these four fertilization regimes to soil properties, fungal diversity and community composition. The results showed that applying organic manure significantly influenced soil properties. Illumina MiSeq sequencing and its analysis revealed that organic manure fertilization significantly changed soil fungal alpha diversity, but chemical fertilization did not. Although soil fungal community composition did not differ significantly among all the fertilization regimes at the phylum and class levels, they did show differences in the abundance of dominant fungi. Yet at the genus level, soil fungal community composition, abundance, and beta diversity was affected by all fertilization regimes. Application of organic manure also reduced the abundance of soil-born fungal pathogens such as Fusarium. Our results suggest that long-term application of organic manure could markedly improve soil properties, altering soil fungal community composition and its diversity. Moreover, organic manure fertilization could limit soil-born fungal diseases, to further contribute to soil ecosystem sustainability.

20.
Opt Lett ; 45(9): 2534-2537, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32356809

RESUMO

We demonstrate the rapid photodarkening (PD) phenomenon in Tm-doped fiber (TDF) core pumped by a laser at 1080 nm and the bleaching effect of deuterium (${{\rm D}_2}$D2) on PD TDF. By ${{\rm D}_2}$D2 loading for seven days, the PD-induced excess loss (PIEL) in the visible (VIS) and near-infrared (NIR) region have been largely eliminated, and no degradation was observed within 30 days. PD resistance of the ${{\rm D}_2}$D2 pretreated TDF has been investigated as well. The formation of color centers based on defects and precursors in the silica matrix and the mechanism of ${{\rm D}_2}$D2 bleaching are discussed.

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