Publications by authors named "Xiaomeng Chen"

47 Publications

Enhanced immune effects and protection conferred by simultaneously targeting GAPDH, SeM, and EAG of S. equi via TLR4.

Res Vet Sci 2021 Jun 8;138:100-108. Epub 2021 Jun 8.

Department of Microbiology and Immunology, College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, Xinjiang, China. Electronic address:

Strangles, which is caused by Streptococcus equi subspecies equi, is one of the most prevalent equine infectious diseases and poses heavy economic losses worldwide. Although various vaccines have been used for decades, they seemed to be sub-optimal to demonstrate effective protection, and the antigen component of vaccines against S. equi remains to be optimized. In the present study, three target antigens (M-like protein, α2-macroglobulin and IgG-binding protein, and glyceraldehyde-3-phosphate dehydrogenase) were selected and expressed. Mice were immunized and challenged, and their immune response and efficacy were evaluated. The results revealed that this optimized multi-antigen treatment elicited a high expression level of T-cell receptor, major histocompatibility complex I, toll-like receptor TLR-4, and increased specific antibody. In addition, the challenge experiment showed an evidently improved protection efficacy. The present work demonstrated that these three proteins might be used as a promising multicomponent subunit vaccine candidate against S. equi infection.
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http://dx.doi.org/10.1016/j.rvsc.2021.06.001DOI Listing
June 2021

Validity of using mobile phone surveys to evaluate community health worker program in Mali.

BMC Med Res Methodol 2021 Jun 3;21(1):115. Epub 2021 Jun 3.

Department of International Health, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe St, Baltimore, MD, 21205, USA.

Background: The monitoring and evaluation of public health programs based on traditional face-to-face interviews in hard-to-reach and unstable regions present many challenges. Mobile phone-based methods are considered to be an effective alternative, but the validity of mobile phone-based data for assessing implementation strength has not been sufficiently studied yet. Nested within an evaluation project for an integrated community case management (iCCM) and family planning program in Mali, this study aimed to assess the validity of a mobile phone-based health provider survey to measure the implementation strength of this program.

Methods: From July to August 2018, a cross-sectional survey was conducted among the community health workers (ASCs) from six rural districts working with the iCCM and family planning program. ASCs were first reached to complete the mobile phone-based survey; within a week, ASCs were visited in their communities to complete the in-person survey. Both surveys used identical implementation strength tools to collect data on program activities related to iCCM and family planning. Sensitivity and specificity were calculated for each implementation strength indicator collected from the phone-based survey, with the in-person survey as the gold standard. A threshold of ≥ 80% for sensitivity and specificity was considered adequate for evaluation purposes.

Results: Of the 157 ASCs interviewed by mobile phone, 115 (73.2%) were reached in person. Most of the training (2/2 indicators), supervision (2/3), treatment/modern contraceptive supply (9/9), and reporting (3/3) indicators reached the 80% threshold for sensitivity, while only one supervision indicator and one supply indicator reached 80% for specificity. In contrast, most of the stock-out indicators (8/9) reached 80% for specificity, while only two indicators reached the threshold for sensitivity.

Conclusions: The validity of mobile phone-based data was adequate for general training, supervision, and supply indicators for iCCM and family planning. With sufficient mobile phone coverage and reliable mobile network connection, mobile phone-based surveys are useful as an alternative for data collection to assess the implementation strength of general activities in hard-to-reach areas.
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http://dx.doi.org/10.1186/s12874-021-01317-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8176601PMC
June 2021

CLEC-1 Acts as a Negative Regulator of Dectin-1 Induced Host Inflammatory Response Signature in Aspergillus fumigatus Keratitis.

Invest Ophthalmol Vis Sci 2021 May;62(6):28

Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao, China.

Purpose: C-type lectin-like receptor-1 (CLEC-1) is a member of the Dectin-1 cluster of pattern recognition receptors (PRRs). It is involved in host immunity, has immunoregulatory function, and supports allograft tolerance. Our study aimed to describe the role of CLEC-1 in response to fungal keratitis, in situ, in vivo, and in vitro.

Methods: Quantitative polymerase chain reaction (qRT-PCR) and immunofluorescence were used to detect the expression of CLEC-1 in corneas of patients with Aspergillus fumigatus (A. fumigatus) keratitis. In vitro and in vivo experiments were designed in THP-1 macrophages and C57BL/6 mouse models, respectively. The expression of CLEC-1 in corneas of mice model was determined by qRT-PCR, Western blot, and immunofluorescence. CLEC-1 overexpression in mouse corneas was achieved by intrastromal injection of adeno-associated virus (AAV) vectors. Disease response was evaluated by slit-lamp photography, clinical score, and colony forming unit (CFU). Bioluminescence imaging system image acquisition, myeloperoxidase (MPO) assays, immunofluorescence staining, qRT-PCR, and Western blot were used to investigate the role of CLEC-1. To further define the role of CLEC-1, we used lentivirus vectors to overexpress CLEC-1 or/and Dectin-1 in THP-1 macrophages.

Results: The expression of CLEC-1 was increased in corneas of patients with A. fumigatus keratitis. In corneas of mice from the A. fumigatus keratitis model, the expression of CLEC-1 was decreased in the acute inflammatory stage and increased during convalescence. Following Natamycin treatment, CLEC-1 was upregulated in A. fumigatus keratitis mice. Compared with normal C57BL/6 mice, overexpression of CLEC-1 converted the characteristic susceptible response to resistance, as demonstrated by slit-lamp photography and clinical score. In vivo studies revealed decreased MPO levels and neutrophils recruitment and higher fungal load after the upregulation of CLEC-1. Compared with control corneas, CLEC-1 overexpression impaired corneal pro-inflammatory cytokine IL-1β production.

Conclusions: These findings demonstrate that CLEC-1 may act as a negative regulator of Dectin-1 induced host inflammatory response via suppressing neutrophils recruitment and production of pro-inflammatory cytokine IL-1β production in response to A. fumigatus keratitis.
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http://dx.doi.org/10.1167/iovs.62.6.28DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8164365PMC
May 2021

δ-MnO changed the structure of humic-like acid during co-composting of chicken manure and rice straw.

Waste Manag 2021 Jun 3;128:16-24. Epub 2021 May 3.

College of Life Science, Northeast Agricultural University, Harbin 150030, China.

Improving the structure and quantity of humus is important to reduce agriculture organic waste by composting. The present study was aimed to assess the role of δ-MnO on humus fractions formation during co-composting of chicken manure and rice straw. Two tests (control group (CK), the addition of δ-MnO (M)) were carried out. The results showed that organic matter content decreased by 34% and 29% at M and CK, suggesting the process of organic waste disposal was accelerated by adding δ-MnO. The structures and quantity of fulvic acid (FA) and humic acid (HA) (as the main fractions of humus) were investigated. The δ-MnO had no significant effect on improving the concentration of FA and HA (p > 0.05). However, the addition of δ-MnO caused different effects on the FA and HA structure. The humification degree of FA improved, while bioavailability of HA increased through adding δ-MnO. The addition of δ-MnO rephased the bacterial community structure, slowing down the succession rate of the bacterial community in M composting. After adding δ-MnO the structural equation modeling results showed that environmental factors could directly drive changes in FA and HA by modulating the bacterial community. Furthermore, the role of FA and HA in the soil amendment was also demonstrated. Therefore, the addition of MnO might be promising for agriculture organic waste treatment and environmental repair during composting.
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http://dx.doi.org/10.1016/j.wasman.2021.04.039DOI Listing
June 2021

Pre-Kidney Transplant Unintentional Weight Loss Leads to Worse Post-Kidney Transplant Outcomes.

Nephrol Dial Transplant 2021 Apr 24. Epub 2021 Apr 24.

Department of Surgery, Johns Hopkins School of Medicine, Baltimore, MD, USA.

Background: Weight loss before kidney transplant (KT) is a known risk factor for weight gain and mortality; however, whereas unintentional weight loss is a marker of vulnerability, intentional weight loss might improve health. We tested whether pre-KT unintentional and intentional weight loss have differing associations with post-KT weight gain, graft loss, and mortality.

Methods: Among 919 KT recipients from a prospective cohort study, we used adjusted mixed effects models to estimate post-KT BMI trajectories, and Cox models to estimate death-uncensored graft loss, death-censored graft loss, and all-cause mortality by one-year pre-KT weight change category [stable weight (change≤5%), intentional weight loss (loss>5%), unintentional weight loss (loss>5%), and weight gain (gain>5%)].

Results: Mean age was 53 years, 38% were Black, and 40% were female. In the pre-KT year, 62% of recipients had stable weight, 15% had weight gain, 14% had unintentional weight loss, and 10% had intentional weight loss. In the first three years post-KT, BMI increases were similar among those with pre-KT weight gain and intentional weight loss, and lower compared to those with unintentional weight loss (difference +0.79 kg/m2/year, 95% CI: 0.50-1.08 kg/m2/year, p < 0.001). Only unintentional weight loss was independently associated with higher death-uncensored graft loss (adjusted Hazard Ratio [aHR]=1.80, 95% CI:1.23-2.62), death-censored graft loss (aHR=1.91, 95% CI:1.12-3.26) and mortality (aHR=1.72, 95% CI:1.06-2.79) relative to stable pre-KT weight.

Conclusions: This study suggests that unintentional, but not intentional, pre-KT weight loss is an independent risk factor for adverse post-KT outcomes.
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http://dx.doi.org/10.1093/ndt/gfab164DOI Listing
April 2021

Evaluating the phytotoxicity of dissolved organic matter derived from black carbon.

Sci Total Environ 2021 Jul 5;778:146231. Epub 2021 Mar 5.

College of Life Science, Northeast Agricultural University, Harbin 150030, China.

Dissolved organic matter (DOM) derived from black carbon (BC) can migrate from soil to river by rainfall or snow melting in nature. Because of the incomplete biomass combustion, BC produced at various temperatures is mixed, which is hard to divide the DOM at single temperature. Then it is difficult to explore the properties and risks of DOM in detail. Therefore, corn straws were selected to prepare BC under different heating temperature (200 °C, 250 °C, 300 °C, 350 °C, 400 °C and 450 °C). Germination index combined the excitation-emission matrix-parallel factor (PARAFAC) and two-dimensional correlation spectra was employed to clarify the phytotoxicity and the PARAFAC components of DOM derived from BC at single temperature. Results showed that BC was hard to dissolve in water, but most of its DOM were toxic. Heating temperature promoted the formation of simple and complex fluorescent components. Combined with volume integration, it is the complex peaks of fluorescent components to determine the phytotoxicity of DOM derived from BC. These results would help to build a deep understanding of the fluorescence characteristics and toxicity of BC at different temperatures and emphasize the importance of reducing straw by burning.
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http://dx.doi.org/10.1016/j.scitotenv.2021.146231DOI Listing
July 2021

The action difference of metabolic regulators on carbon conversion during different agricultural organic wastes composting.

Bioresour Technol 2021 Jun 25;329:124902. Epub 2021 Feb 25.

Heilongjiang Province Environmental Science Research Institute, Harbin 150056, China.

The purpose of this study is to explore the action characteristics of metabolic regulators like adenosine tri-phosphate (ATP) and malonic acid (MA) during rice straw (RS) and fruit and vegetable waste (FVW) composting. Results showed that due to the easy degradation difference, ATP and MA reduced CO emission in RS and FVW, respectively. Moreover, adding ATP and MA increased humic acids (HA) content in FVW more significantly (p < 0.05), especially for ATP. However, adding MA accelerated organic matter degradation during RS composting, which was basically consistent with CO emission, but it was not effective in promoting HA formation. Furthermore, the microbial community was reshaped by adding ATP and MA. Eventually, structural equation model further confirmed that adding metabolic regulators enhanced the biotic and abiotic pathways of HA formation, and the promotion effect of adding ATP was more obvious. The study has great practical significance for the dispose of agricultural waste.
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http://dx.doi.org/10.1016/j.biortech.2021.124902DOI Listing
June 2021

Genomic Characterization Provides an Insight into the Pathogenicity of the Poplar Canker Bacterium .

Genes (Basel) 2021 Feb 9;12(2). Epub 2021 Feb 9.

Beijing Key Laboratory for Forest Pest Control, College of Forestry, Beijing Forestry University, Beijing 100083, China.

An emerging poplar canker caused by the gram-negative bacterium, , has led to high mortality of hybrid poplars in China and Europe. The molecular bases of pathogenicity and bark adaptation of have become a focus of recent research. This study revealed the whole genome sequence and identified putative virulence factors of . A high-quality genome sequence was assembled de novo, with a genome size of 3,859,707 bp, containing approximately 3434 genes and 107 RNAs (75 tRNA, 22 rRNA, and 10 ncRNA). The genome contained 380 virulence-associated genes, mainly encoding for adhesion, extracellular enzymes, secretory systems, and two-component transduction systems. The genome had 110 carbohydrate-active enzyme (CAZy)-coding genes and putative secreted proteins. The antibiotic-resistance database annotation listed that was resistant to penicillin, fluoroquinolone, and kasugamycin. Analysis of comparative genomics found that exhibited the highest homology with the genome and encompassed 1905 specific genes, 1769 dispensable genes, and 1381 conserved genes, suggesting high evolutionary diversity and genomic plasticity. Moreover, the pan genome analysis revealed that the N-5-1 genome is an open genome. These findings provide important resources for understanding the molecular basis of the pathogenicity and biology of and the poplar-bacterium interaction.
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http://dx.doi.org/10.3390/genes12020246DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7914447PMC
February 2021

Changes in Functional Status Among Kidney Transplant Recipients: Data From the Scientific Registry of Transplant Recipients.

Transplantation 2021 Jan 12. Epub 2021 Jan 12.

Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD.

Background: With stressors of dialysis pre-KT and restoration of kidney function post-KT, it is likely that KT recipients experience a decline in functional status while on the waitlist and improvements post-KT.

Methods: We leveraged 224,832 KT recipients from the national registry (SRTR, 2/1990-5/2019) with measured Karnofsky Performance Status (KPS, 0-100%) at listing, KT admission, and post-KT. We quantified the change in KPS from listing to KT using generalized linear models. We described post-KT KPS trajectories using adjusted mixed effects models and tested whether those trajectories differed by age, sex, race, and diabetes status using a Wald test among all KT recipients. We then quantified risk adverse post-KT outcomes (mortality and all-cause graft loss (ACGL)) by preoperative KPS and time-varying KPS.

Results: Mean KPS declined from listing (83.7%) to admission (78.9%) (mean=4.76%, 95%CI:-4.82,-4.70). After adjustment, mean KPS improved post-KT (slope=0.89%/year, 95%CI:0.87,0.91); younger, female, non-Black, and diabetic recipients experienced greater post-KT improvements (pinteractions<0.001). Lower KPS (per 10% decrease) at admission was associated with greater mortality (aHR=1.11, 95%CI:1.10,1.11) and ACGL (aHR=1.08, 95%CI:1.08,1.09) risk. Lower post-KT KPS (per 10% decrease; time-varying) were more strongly associated with mortality (aHR=1.93, 95%CI:1.92,1.94) and ACGL (aHR=1.84, v95%CI:1.83,1.85).

Conclusions: Functional status declines pre-KT and improves post-KT in the national registry. Despite post-KT improvements, poorer functional status at KT and post-KT are associated with greater mortality and ACGL risk. Due to its dynamic nature, clinicians should repeatedly screen for lower functional status pre-KT to refer vulnerable patients to prehabilitation in hopes of reducing risk of adverse post-KT outcomes.
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http://dx.doi.org/10.1097/TP.0000000000003608DOI Listing
January 2021

Anti-quorum Sensing and Protective Efficacies of Naringin Against Infection in .

Front Microbiol 2020 3;11:600622. Epub 2020 Dec 3.

Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China.

It is now well known that the quorum sensing (QS) mechanism coordinates the production of several virulence factors and biofilm formation in most pathogenic microorganisms. is a prime pathogen responsible for frequent outbreaks in aquaculture settings. Recent studies have also continuously reported that regulates virulence factor production and biofilm formation through the QS system. In addition to the presence of antibiotic resistance genes, biofilm-mediated antibiotic resistance increases the severity of infections. To control the bacterial pathogenesis and subsequent infections, targeting the QS mechanism has become one of the best alternative methods. Though very few compounds were identified as QS inhibitors against , to date, the screening and identification of new and effective natural QS inhibitors is a dire necessity to control the infectious . The present study endorses naringin (NA) as an anti-QS and anti-infective agent against . Initially, the NA showed a concentration-dependent biofilm reduction against . Furthermore, the results of microscopic analyses and quantitative virulence assays displayed the promise of NA as a potential anti-QS agent. Subsequently, the downregulation of , , and validate the interference of NA in virulence gene expression. Furthermore, the assays were carried out in zebrafish model system to evaluate the anti-infective potential of NA. The outcome of the immersion challenge assay showed that the recovery rate of the zebrafish has substantially increased upon treatment with NA. Furthermore, the quantification of the bacterial load upon NA treatment showed a decreased level of bacterial counts in zebrafish when compared to the untreated control. Moreover, the NA treatment averts the pathogen-induced histoarchitecture damages in vital organs of zebrafish, compared to their respective controls. The current study has thus analyzed the anti-QS and anti-infective capabilities of NA and could be employed to formulate effective treatment measures against infections.
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http://dx.doi.org/10.3389/fmicb.2020.600622DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7793879PMC
December 2020

Isolation and yield optimization of lipopeptides from Bacillus subtilis Z-14 active against wheat take-all caused by Gaeumannomyces graminis var. tritici.

J Sep Sci 2021 Feb 18;44(4):931-940. Epub 2021 Jan 18.

College of Life Science, Hebei Agricultural University, Baoding, P. R. China.

Wheat take-all, caused by the soil-borne fungus Gaeumannomyces graminis var. tritici, is one of the major constraints on wheat production worldwide. Bacillus subtilis Z-14 exerts significant biocontrol activity against wheat take-all, and lipopeptide antibiotics are the main antifungal substances. Herein, lipopeptide antibiotics C14-C15 iturin A, C14-C16 fengycin A, and C15-C17 fengycin B from B. subtilis Z-14 culture filtrates were separated and identified by high-performance liquid chromatography, matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry, and mass spectrometry/mass spectrometry, respectively. The optimal medium components for Z-14 lipopeptide antibiotic production were 3.85 g/L corn flour, 1.57 g/L soybean meal, 0.03 g/L FeSO ·7H O, 0.2 g/L NaH PO ·2H O, and 0.4 g/L Na HPO ·2H O. Quantification analysis by high-performance liquid chromatography showed that fengycins played a main role in antifungal activity against Gaeumannomyces graminis var. tritici. Quantitative reverse transcription polymerase chain reaction showed that lipopeptide synthesis genes fenD and ituC reached maximum expression levels after 48 h of fermentation. The strongest control of wheat take-all by Z-14 was achieved by adding 30 mL of culture filtrate per 350 g of soil in pot experiments, during which disease reduction reached 88.15%. This study provides theoretical support and a material basis for the prevention and treatment of wheat take-all disease.
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http://dx.doi.org/10.1002/jssc.201901274DOI Listing
February 2021

The "quality" and "quantity" of microbial species drive the degradation of cellulose during composting.

Bioresour Technol 2021 Jan 19;320(Pt B):124425. Epub 2020 Nov 19.

College of Life Sciences and Technology, Harbin Normal University, Harbin 150025, China; College of Life Science, Northeast Agricultural University, Harbin 150030, China. Electronic address:

The aim of this study was to explore the contribution of microbial community to cellulose degradation during cellulosic wastes composting. Three raw materials with different cellulose content were employed, including rice straws (RS), leaves (L) and mushroom dregs (MD). The cellulose degraded by 92.09%, 56.68% and 40.03% during RS, L and MD composting, respectively, which could be explained by cellulases activity. Besides, each cellulase were only linked to a specific group of bacteria, thus cellulose degradation needed the cooperation of various microorganisms. Ultimately, structural equation models verified that the richness and evenness of microbial community were the primary driving factors of cellulose degradation. The richness symbolized microbial functionality, which was equivalent to the "quality" of microbial species. The evenness symbolized the scope of function, which was equivalent to the "quantity". Therefore, the "quality" and "quantity" of microbial species drove cellulose degradation during RS, L and MD composting.
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http://dx.doi.org/10.1016/j.biortech.2020.124425DOI Listing
January 2021

Influence of malonic acid and manganese dioxide on humic substance formation and inhibition of CO release during composting.

Bioresour Technol 2020 Dec 4;318:124075. Epub 2020 Sep 4.

Heilongjiang Province Environmental Science Research Institute, Harbin 150056, China.

The aim of thisstudy was to explore the effects of malonic acid (MA), manganese dioxide (MnO), malonic acid combined with manganese dioxide (MA + MnO) additionon reducing CO emission and promoting humic substance (HS) formation during composting. The result showed that the addition of MA and MnO were an efficient way to reduce CO emission. Meanwhile, the CO emissions in the MA + MnO treatment was 36.8% less than that of the CK, and the amount of humic acid (HA) produced in the MnO treatment was 38.7% higher than that of the CK. Structural equation models demonstrated that the addition of exogenoussubstance promoted the conversion of amino acids and reducing sugars to HA. The addition of exogenous substances was the main reason for influencing the concentration of HA. In general, this research provided theoretical supports for the addition of exogenous substances to promote HA formation during composting.
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http://dx.doi.org/10.1016/j.biortech.2020.124075DOI Listing
December 2020

Speciation, toxicity mechanism and remediation ways of heavy metals during composting: A novel theoretical microbial remediation method is proposed.

J Environ Manage 2020 Oct 20;272:111109. Epub 2020 Jul 20.

College of Life Science, Northeast Agricultural University, Harbin, 150030, China. Electronic address:

Heavy metals (HM) pollution is a major limitation to the application of composting products. Therefore, mitigating the toxicity of HM has attracted wide attention during composting. The toxicity of HM is mainly acted on microorganisms during composting, and the toxicity of different HM speciation is obviously various. There are many pathways to change the speciation to reduce the toxicity during composting. Therefore, in this review, the speciation distribution, toxicity mechanism and remediation ways of HM during composting were discussed in order to better solve HM pollution. The microbial remediation technology holds enormous potential to remediate for HM without damaging composting, however, it is hard to extract HM. The innovation of this review was to outline microbial remediation strategies for HM during composting based on two mechanisms of microbial remediation: extracellular adsorption and intracellular sequestration, to solve the problem how to extract microbial agents from the compost. Ultimately, a novel theoretical method of microbial remediation was proposed to remove HM from the compost.
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http://dx.doi.org/10.1016/j.jenvman.2020.111109DOI Listing
October 2020

Reconstruction of core microbes based on producing lignocellulolytic enzymes causing by bacterial inoculation during rice straw composting.

Bioresour Technol 2020 Nov 17;315:123849. Epub 2020 Jul 17.

Ecological and Environmental Monitoring Center of Suihua, 152052, China.

The aim of this paper was to identify the core microbes of producing lignocellulolytic enzymes during rice straw composting with functional bacterial agents inoculation. The results indicated that inoculation functional bacterial agents accelerated the degradation of organic matter and coarse fiber content by 7.58%, 8.82%, which were due to the fact that key enzymes and core microbes were stimulated. In addition, inoculation have reconstructed core microbes of producing lignocellulase. Meanwhile, inoculation functional bacterial agents not only as core bacteria to produce cellulase, xylanase and manganese peroxidase (MnP), but also increased most core microbial abundance. Redundancy analysis indicated that CMCase, xylanase, total nitrogen and MnP as key factors to affect the degradation of organic fractions in the core bacterial communities, while in the core fungal communities, were mainly affected by environmental factors (except for MnP). This study provided a theoretical basis for the efficiently degradation during agricultural wastes composting.
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http://dx.doi.org/10.1016/j.biortech.2020.123849DOI Listing
November 2020

Frailty Prevalence in Younger End-Stage Kidney Disease Patients Undergoing Dialysis and Transplantation.

Am J Nephrol 2020 8;51(7):501-510. Epub 2020 Jul 8.

Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA,

Background: Frailty, originally characterized in community-dwelling older adults, is increasingly being studied and implemented for adult patients with end-stage kidney disease (ESKD) of all ages (>18 years). Frailty prevalence and manifestation are unclear in younger adults (18-64 years) with ESKD; differences likely exist based on whether the patients are treated with hemodialysis (HD) or kidney transplantation (KT).

Methods: We leveraged 3 cohorts: 378 adults initiating HD (2008-2012), 4,304 adult KT candidates (2009-2019), and 1,396 KT recipients (2008-2019). The frailty phenotype was measured within 6 months of dialysis initiation, at KT evaluation, and KT admission. Prevalence of frailty and its components was estimated by age (≥65 vs. <65 years). A Wald test for interactions was used to test whether risk factors for frailty differed by age.

Results: In all 3 cohorts, frailty prevalence was higher among older than younger adults (HD: 71.4 vs. 47.3%; candidates: 25.4 vs. 18.8%; recipients: 20.8 vs. 14.3%). In all cohorts, older patients were more likely to have slowness and weakness but less likely to report exhaustion. Among candidates, older age (odds ratio [OR] = 1.79, 95% CI: 1.47-2.17), non-Hispanic black race (OR = 1.30, 95% CI: 1.08-1.57), and dialysis type (HD vs. no dialysis: OR = 2.06, 95% CI: 1.61-2.64; peritoneal dialysis vs. no dialysis: OR = 1.78, 95% CI: 1.28-2.48) were associated with frailty prevalence, but sex and Hispanic ethnicity were not. These associations did not differ by age (pinteractions > 0.1). Similar results were observed for recipients and HD patients.

Conclusions: Although frailty prevalence increases with age, younger patients have a high burden. Clinicians caring for this vulnerable population should recognize that younger patients may experience frailty and screen all age groups.
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http://dx.doi.org/10.1159/000508576DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7442041PMC
July 2020

Label-free and self-assembled fluorescent DNA nanopompom for determination of miRNA-21.

Mikrochim Acta 2020 07 7;187(8):432. Epub 2020 Jul 7.

Department of Gastrointestinal Surgery, The Second Clinical Medicine College (Shenzhen People's Hospital) of Jinan University, Shenzhen, 518020, Guangdong, China.

A label-free fluorescence method based on self-assembled DNA nanopompom has been developed for miRNA-21 detection. In the presence of miRNA-21, three DNA hairpin probes with split G-quadruplex assemble the DNA nanopompom. Based on the isothermal toehold-mediated DNA strand displacement reaction, the target miRNA can be catalytically recycled and trigger three DNA hairpin probes to self-assemble the DNA nanopompom and release the G-quadruplex. The formation of the G-quadruplex increases the fluorescence emission intensity of thioflavin. For thioflavin-based miRNA-21 detection, the excitation and emission wavelengths are set to 425 nm and 490 nm, respectively. The limit of detection for miRNA-21 is 0.8 pM according to F/F0 = 0.0031 × C + 1.0382 (R = 0.9978). This sensing system provides a low-cost, effective, and convenient method for miRNA detection, which holds great potential in biochemical diagnosis and clinical practice. Graphical abstract Label-free and self-assembled fluorescent DNA nanopompom for miRNA detection.
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http://dx.doi.org/10.1007/s00604-020-04377-6DOI Listing
July 2020

Selective pressures of heavy metals on microbial community determine microbial functional roles during composting: Sensitive, resistant and actor.

J Hazard Mater 2020 11 19;398:122858. Epub 2020 May 19.

Heilongjiang Province Environmental Science Research Institute, Harbin 150056, China.

Heavy metals (HM) pollution exerts an effect on microbial community composition and structure during composting, the way how microbial community responses to HM pressure is remain poorly understood though. The aim of this study was to explore functional roles of microorganisms based on selective pressures of HM (Cu, Zn and Cd). The results of microbial resistance showed that the toxicity of metals to microorganisms were Cu > Zn > Cd during composting. Cu and Zn were more toxic for microorganisms during composting when compared with Cd. However, microorganisms had a longer lag period to grow under Zn stress through microbial tolerance determination. In addition, the microbial catalase activity generally decreased and protease activity generally increased, thus microorganisms became more adaptable to HM stress during composting. The experimental results confirmed the existence of sensitive, resistant and actor microorganisms during beef cattle and chicken manures composting. Ultimately, the resistant, sensitive and actor microorganisms at genus level were distinguished under HM pressure based on the network analysis and structural equation models, including 85 resistant microorganisms, 5 sensitive microorganisms and 6 actor microorganisms. This would be helpful to understand the microbial succession process under HM stress and identify functional strains of HM remediation.
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http://dx.doi.org/10.1016/j.jhazmat.2020.122858DOI Listing
November 2020

Academic Self-Efficacy, Social Support, and Professional Identity Among Preservice Special Education Teachers in China.

Front Psychol 2020 13;11:374. Epub 2020 Mar 13.

Special Education Department, School of Education, Guangzhou University, Guangzhou, China.

The relationship among the social support, professional identity, and academic self-efficacy (ASE) of Chinese preservice special education teachers are explored by measuring the perceived social support, professional identity, and ASE of 302 undergraduate students. Results of the multiple regression are as follows. (1) A significant positive correlation exists among ASE, social support, and professional identity. When preservice special education teachers perceive high social support, they have a high sense of professional identity and high ASE. (2) Professional identity exerts a full mediation effect on the relationship between social support and ASE. In particular, social support positively influences ASE via professional identity. The results are discussed at the end of this paper and recommendations for improving the ASE of preservice special education teachers are presented.
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http://dx.doi.org/10.3389/fpsyg.2020.00374DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7082401PMC
March 2020

Elucidating the negative effect of denitrification on aromatic humic substance formation during sludge aerobic fermentation.

J Hazard Mater 2020 04 13;388:122086. Epub 2020 Jan 13.

College of Life Science, Northeast Agricultural University, Harbin 150030, China. Electronic address:

Humic substance (HS), as an aromatic compound, is the core product of aerobic fermentation. Denitrification-dependent degradation of aromatic compounds have been repeatedly observed in environment. However, few studies have elucidated the relationship between denitrification and aromatic HS during sludge aerobic fermentation. This study was conducted to investigate the effect of enhanced denitrification on aromatic HS formation. On the 24th day of sludge aerobic fermentation, five tests (CK, Run1, Run2, Run3 and Run4) were executed, and nitrate concentrations were adjusted to 480 ± 20, 500 ± 20, 1000 ± 20, 1500 ± 20 and 2000 ± 20 mg/kg with potassium nitrate, respectively. Analytical results demonstrated that nitrate addition increased denitrifying genes abundance and enhanced denitrification, which further reduced aromatic HS formation (p < 0.05). Especially in Run3, the concentrations of HS and humic acid on the 52nd day dramatically decreased by 12.9 % and 34.2 % in comparison with those on the 31st day. High-throughput sequencing revealed that enhanced denitrification effectively stimulated the metabolism of denitrifying microorganisms with aromatic-degrading capability. Co-occurring network analysis indicated that some keystone taxa of denitrification aromatic-degrading microorganisms involved in the conversion of nitrate to nitrite were the most crucial for enhancing denitrification and reducing aromatic HS formation.
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http://dx.doi.org/10.1016/j.jhazmat.2020.122086DOI Listing
April 2020

Core microorganisms promote the transformation of DOM fractions with different molecular weights to improve the stability during composting.

Bioresour Technol 2020 Mar 9;299:122575. Epub 2019 Dec 9.

College of Life Science, Northeast Agricultural University, Harbin 150030, China. Electronic address:

Transformation of DOM fractions with different molecular weights during composting of chicken manure (CM), garden waste (GW) and municipal solid waste (MSW) was evaluated in this study. The results revealed that DOM concentrations decreased by 49.8%, 53.9% and 86.4% during CM, GW and MSW composting, respectively. Meanwhile, low molecular weight (<650 Da) DOM was visibly transformed into high molecular weight (>10 kDa) DOM for enhancing their stability during composting. Core microorganisms promoting DOM stabilization were identified by network analysis, such as Prosthecobacter, Paenalcaligenes and Solibacillus. In addition, DOM composition was also related to the relative abundance of microbial metabolic function, such as chemoheterotrophy and aerobic chemoheterotrophy. Moreover, temperature, moisture and pH were identified as the key physicochemical factors affecting the DOM stabilization mediated by core microorganisms during composting. These above findings are helpful to regulate the DOM stabilization during composting and improve the quality of final composts.
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http://dx.doi.org/10.1016/j.biortech.2019.122575DOI Listing
March 2020

Inhibitory Abilities of Isolates and Their Culture Filtrates against the Gray Mold Caused by on Postharvest Fruit.

Plant Pathol J 2019 Oct 1;35(5):425-436. Epub 2019 Oct 1.

College of Life Science, Hebei Agricultural University, Baoding 071001, China.

, a major phytopathogenic fungus, has been reported to infect more than 200 crop species worldwide, and it causes massive losses in yield. The aim of this study was to evaluate the inhibitory abilities and effects of RS-25, MG-4, Z-14, and Pnf-4 and their culture filtrates and extracts against the gray mold caused by on postharvest tomato, strawberry, and grapefruit. The results revealed that the cells of Z-14, culture filtrate of RS-25, and cells of Z-14 showed the strongest biocontrol activity against the gray mold on the strawberry, grape, and tomato fruit, respectively. All the strains produced volatile organic compounds (VOCs), and the VOCs of Pnf-4 displayed the highest inhibition values. Based on headspace solid-phase microextraction in combination with gas chromatography-mass spectrometry, esters accounted for the largest percentage of the VOCs produced by RS-25, MG-4, Z-14, and Pnf-4 (36.80%, 29.58%, 30.78%, and 36.26%, respectively). All the strains showed potent cellulase and protease activities, but no chitinase activity. RS-25, Z-14, and MG-4, but not Pnf-4, grew on chrome azurol S agar, and an orange halo was formed around the colonies. All the strains showed biofilm formation, fruit colonization, and lipopeptide production, which may be the main modes of action of the antagonists against on the fruit. This study provides the basis for developing natural biocontrol agents against the gray mold caused by on postharvest fruit.
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http://dx.doi.org/10.5423/PPJ.OA.03.2019.0064DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6788410PMC
October 2019

Recognition of the neutral sugars conversion induced by bacterial community during lignocellulose wastes composting.

Bioresour Technol 2019 Dec 16;294:122153. Epub 2019 Sep 16.

Heilongjiang Province Environmental Monitoring Centre, Harbin 150056, China.

The aim of this study was to explore the conversion characteristics of neutral sugars during different lignocellulose wastes composting from rice straw (RS), leaf (L) and mushroom dreg (MD). The results showed that the changes of neutral sugars were different during different wastes composting, but the changes of various hexose or pentose were similar during composting of the same material. The diversity of bacterial community led to different conversion characteristics of neutral sugars. During RS composting, each neutral sugar was transformed by a specific group of bacteria. However, a group of bacteria could transform multiple neutral sugars during MD and L composting. Furthermore, GM/AX value was first applied to composting, which could be used to characterize the conversion of neutral sugars during composting. This will help to provide more efficient recommendations for lignocellulose wastes treatment and accelerating humic substances synthesis during composting.
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http://dx.doi.org/10.1016/j.biortech.2019.122153DOI Listing
December 2019

A novel method for removing heavy metals from composting system: The combination of functional bacteria and adsorbent materials.

Bioresour Technol 2019 Dec 31;293:122095. Epub 2019 Aug 31.

Heilongjiang Province Environmental Monitoring Centre, Harbin 150056, China.

The aim of this study was to remove heavy metals from composting system using a novel method combined functional bacteria with adsorbent materials. Four types of adsorbent materials were selected in this study. Results showed that Cr had significant removal efficiency, especially in sponge treatment (19.09%) and cotton treatment (26.36%). In addition, a significant movement of heavy metals from the outside to adsorbent column was also observed. RDA results indicated that bands 1, 2, 10, 18, 19 and 20 had negative correlations with six types of heavy metals, which contributed to the removal of heavy metals. Structural equation models further confirmed functional bacteria can directly affect the removal of Cu, Cd and Cr. In addition, it can also indirectly remove Pb and Cr by changing native bacteria. In summary, this study suggested the combination of functional bacteria and adsorbent materials was effective to remove heavy metals from composting system.
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http://dx.doi.org/10.1016/j.biortech.2019.122095DOI Listing
December 2019

Effects of exogenous protein-like precursors on humification process during lignocellulose-like biomass composting: Amino acids as the key linker to promote humification process.

Bioresour Technol 2019 Nov 25;291:121882. Epub 2019 Jul 25.

College of Life Science, Northeast Agricultural University, Harbin 150030, China.

The aim of this study is to assess the effectiveness of protein-like precursors addition on promoting humification process during lignocellulose-like biomass composting through adding amino acids to compost. The humification indexes of R1 and R2 was significantly higher than that of CK (P < 0.05). The decreasing ratio of Maillard precursor concentration of R2 and R1 was higher than CK. Amino acids addition affected the bacteria community and environmental factors during composting. Variance partitioning analysis showed that humification process was strengthened with environmental factors, bacteria community, Maillard precursors. Structural equation model (SEM) analysis showed that amino acids had substantial impact on promoting humic acid (HA) formation. The combined application of protein-like wastes and lignocellulose-like wastes was suggested to improve carbon sequestration. This study lays a foundation for economically and effectively managing different types of straws by composting.
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http://dx.doi.org/10.1016/j.biortech.2019.121882DOI Listing
November 2019

The effects of reading mode and braille reading patterns on braille reading speed and comprehension: A study of students with visual impairments in China.

Res Dev Disabil 2019 Aug 22;91:103424. Epub 2019 Jun 22.

School of Education, South China Normal University, Guangzhou, People's Republic of China.

The purpose of this study was to examine the effects of reading mode (oral and silent reading) and braille reading patterns (one-handed pattern, mark pattern, parallel pattern, cooperative pattern) on the reading speed and comprehension of students with visual impairments in China. Seventy-three students with visual impairments aged 10-19 years participated in the study; 48 were students with congenital visual impairments and 25 were students with adventitious visual impairments. The participants' braille reading performance was assessed by the Chinese Reading Comprehension Test. Measurement indicators included reading speed (wpm) and reading comprehension. The results indicated that (1) Reading mode had a significant effect on both reading speed and reading comprehension. More specifically, although participants read faster in silent reading than in oral reading, they demonstrated better reading comprehension in oral reading than in silent reading. (2) There was a significant interaction effect between reading mode and braille reading patterns on reading speed. In particular, participants using cooperative and one-handed patterns read faster than other patterns in silent reading. This difference did not exist in the oral reading mode. (3) There was no difference between the measurement indicators of the students with congenital and adventitious visual impairments. Implications and recommendations are given based on the analyses.
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http://dx.doi.org/10.1016/j.ridd.2019.05.003DOI Listing
August 2019

Assessment contributions of physicochemical properties and bacterial community to mitigate the bioavailability of heavy metals during composting based on structural equation models.

Bioresour Technol 2019 Oct 15;289:121657. Epub 2019 Jun 15.

College of Life Science, Northeast Agricultural University, Harbin 150030, China. Electronic address:

The aim of this study was to explore the pathways to mitigate the bioavailability of heavy metals (HM) during chicken and beef cattle manures composting. For raw materials, HM contents in animal manures from breeding farm were 1.5-3 times as much as that of domestic animal manures. Structural equation models (SEMs) based on denaturing gradient gel electrophoresis (DGGE) showed that mitigating bioavailability of HM was mainly attributed to physicochemical properties (organic matters content and temperature) during beef cattle manures composting. However, both physicochemical properties (organic matters content, temperature, pH and moisture) and bacterial community were critical factors during chicken manures composting. Furthermore, the statistical analysis from high-throughput sequencing verified the results of SEMs. Therefore, the bioavailability of HM will be mitigated by different deactivation pathways according to diverse raw materials composting.
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http://dx.doi.org/10.1016/j.biortech.2019.121657DOI Listing
October 2019

Host bacterial community of MGEs determines the risk of horizontal gene transfer during composting of different animal manures.

Environ Pollut 2019 Jul 8;250:166-174. Epub 2019 Apr 8.

Key Laboratory of Agricultural Microbiology of Heilongjiang Province Science and Technology Department, Northeast Agricultural University, Harbin, 150030, China; College of Life Science, Northeast Agricultural University, Harbin, 150030, China. Electronic address:

Mobile genetic elements (MGEs) play critical roles in transferring antibiotic resistance genes (ARGs) among different microorganisms in the environment. This study aimed to explore the fate of MGEs during chicken manure (CM) and bovine manure (BM) composting to assess horizontal transfer risks of ARGs. The results showed that the removal efficiency of MGEs during CM composting was significantly higher than that during BM composting, because the potential host bacteria of MGEs were eliminated largely during CM composting. Meanwhile, these potential host bacterial communities are significantly influenced by pH, NH, NO and total N, which can be used to regulate host bacterial communities to remove MGEs during composting. Projection pursuit regression further confirmed that composting can effectively reduce the horizontal transfer risk of ARGs, especially for CM composting. These results identified the critical roles of host bacterial communities in MGEs removal during composting of different animal manures.
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http://dx.doi.org/10.1016/j.envpol.2019.04.037DOI Listing
July 2019

Roles of bacterial community in the transformation of organic nitrogen toward enhanced bioavailability during composting with different wastes.

Bioresour Technol 2019 Aug 6;285:121326. Epub 2019 Apr 6.

College of Life Science, Northeast Agricultural University, Harbin 150030, China. Electronic address:

This study aimed to explore the roles of bacterial community in the transformation of bioavailable organic-N (BON) during different wastes composting. BON fractions with different forms and molecular weights were identified in this study. Results indicated that core bacterial communities improved the availability of BON by degrading high molecular weights BON into low molecular weights BON during different wastes composting. A total of fifty-two core bacterial genera involved in BON transformation were identified by network analysis. Three types of high molecular weights BON fractions (amino acid-N, amine-N and amino sugar-N) were degraded by bacteria during chicken manure and garden waste composting, while only amine-N was degraded during municipal solid waste composting. Finally, moisture, C/N and pH were identified as the key operational parameters affecting BON transformation mediated by microorganisms, which can be used to improve bioavailability of organic-N and reduce N loss during composting.
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http://dx.doi.org/10.1016/j.biortech.2019.121326DOI Listing
August 2019

Effects and control of metal nutrients and species on Microcystis aeruginosa growth and bloom.

Water Environ Res 2019 Jan;91(1):21-31

School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, China.

The effects and control of typical metal nutrients, copper, iron, and zinc, on the growth and bloom of Microcystis aeruginosa were investigated with a series of flask-shaking tests. The optimal concentrations of copper, iron, and zinc for algal growth were 0.001, 3-12, and 0.05 mg/L, respectively. The order of toxicity to the alga was Cu > Zn > Fe. The effects of the species, for a trace metal at the same concentrations, on the growth of M. aeruginosa were relatively remarkable. Ionic and complexation species induced more algal growth than the carbonate and sulfide-bound species. Changes in copper concentration and iron species were adopted to adjust and control the bloom of M. aeruginosa. Increases in copper concentrations significantly suppressed the M. aeruginosa bloom. The growth rate of M. aeruginosa slowed significantly when ionic iron was replaced with sulfide-bound iron, and the control of bloom was remarkable. PRACTITIONER POINTS: Using trace metal nutrient species and concentration to regulate and control algal growth and bloom may pave another way for the management of cyanobacterial bloom.
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http://dx.doi.org/10.2175/106143017X15131012188303DOI Listing
January 2019