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1.
Int Immunopharmacol ; 96: 107602, 2021 Mar 24.
Artículo en Inglés | MEDLINE | ID: mdl-33812260

RESUMEN

OBJECTIVES: This systematic review and meta-analysis of randomized controlled trials (RCTs) aimed to investigate the clinical efficacy and safety of tocilizumab for treating patients with COVID-19. METHODS: The PubMed, Embase, Cochrane Library, Clinicaltrials.gov, WHO International Clinical Trials Registry Platform and the preprint server of medRxiv.org were searched from their inception to February 20, 2021. Only RCTs that compared the treatment efficacy and safety of tocilizumab with the placebo or the standard of care for adult patients with COVID-19 were included in this meta-analysis. The primary outcome was 28-day mortality. RESULTS: This meta-analysis included eight RCTs which enrolled a total of 6314 patients for randomization, in which 3267 and 3047 patients were assigned to the tocilizumab and control groups, respectively. The mortality at day 28 was 24.4% and 29.9% in patients in the tocilizumab and control groups, respectively, meaning there was no significant difference observed between these two groups (OR, 0.92; 95% CI, 0.66-1.28; I2 = 62). This finding did not change in the subgroup analysis according to the initial use of MV or steroid while enrollment. The patients receiving tocilizumab had a lower rate of mechanical ventilation (MV) and intensive care unit (ICU) admission at day 28 compared with the control group (MV use: OR, 0.75; 95% CI, 0.62-0.90; I2 = 11; ICU admission: OR, 0.51; 95% CI, 0.28-0.92; I2 = 30). There were no significant differences between these two treatment groups in terms of the risk of treatment-emergent adverse events (AEs) (OR, 1.03; 95% CI, 0.71-1.49; I2 = 43), serious AEs (OR, 0.86; 95% CI, 0.67-1.12; I2 = 0) or infection (OR, 0.87; 95% CI, 0.63-1.20; I2 = 0). CONCLUSIONS: Tocilizumab does not provide a survival benefit for patients with COVID-19, but it may help reduce the risk of MV and ICU admission. In addition, tocilizumab is a safe agent to use for the treatment of COVID-19.

2.
Front Immunol ; 12: 613893, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33815370

RESUMEN

Previous studies have revealed an association between ocular surface disorders and air pollution, few studies have focused on the risk of uveitis. We aimed to investigate whether air pollution increases the risk of uveitis. We used the Taiwan Longitudinal Health Insurance Database (LHID) and the Taiwan Air Quality Monitoring Database (TAQMD) to conduct a retrospective cohort study. Air pollutant concentrations, including those of carbon dioxide (CO2), were grouped into four levels according to quartiles. The outcome was the incidence of uveitis, as defined in the International Classification of Diseases, Ninth Revision. We used univariable and multivariable Cox proportional hazard regression models to calculate the adjusted hazard ratios (aHRs) and determine the potential risk factors of uveitis. Overall, 175,489 subjects were linked to their nearby air quality monitoring stations. We found that for carbon monoxide, the aHRs of uveitis risk for the Q3 and Q4 levels were 1.41 (95% confidence interval (CI) = 1.23-1.61) and 2.19 (95% CI = 1.93-2.47), respectively, in comparison with those for the Q1 level. For nitric oxide, the aHRs for the Q3 and Q4 levels were 1.46 (95% CI = 1.27-1.67) and 2.05 (95% CI = 1.81-2.32), respectively. For nitrogen oxide (NOx), the aHRs for the Q2, Q3, and Q4 levels were 1.27 (95% CI = 1.11-1.44), 1.34 (95% CI = 1.16-1.53), and 1.85 (95% CI = 1.63-2.09), respectively. For total hydrocarbon (THC), the aHRs for the Q2, Q3, and Q4 levels were 1.42 (95% CI = 1.15-1.75), 3.80 (95% CI = 3.16-4.57), and 5.02 (95% CI = 4.19-6.02), respectively. For methane (CH4), the aHRs for the Q3 and Q4 levels were 1.94 (95% CI = 1.60-2.34) and 7.14 (95% CI = 6.01-8.48), respectively. In conclusion, air pollution was significantly associated with incidental uveitis, especially at high THC and CH4 levels. Furthermore, the uveitis risk appeared to increase with increasing NOx and THC levels.

3.
Anal Chem ; 2021 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-33821620

RESUMEN

Sensitivity-improved versions of two-dimensional (2D) 13C-1H HSQC (heteronuclear single quantum coherence) and HSQC-TOCSY (HSQC-total correlation spectroscopy) NMR experiments optimized for small biological molecules and their complex mixtures encountered in metabolomics are presented that preserve the magnetization of 1H spins not directly attached to 13C spins. This allows (i) the application of rapid acquisition techniques to substantially shorten measurement time and (ii) their incorporation into supersequences (NOAH-NMR by ordered acquisition using 1H detection) for the compact acquisition of multiple 2D NMR data sets with significant gains in sensitivity, resolution, and/or time. The new pulse sequences, which are demonstrated for both metabolite model mixtures and mouse urine, offer an attractive approach for the efficient measurement of multiple 2D NMR spectra (HSQCsi and/or HSQCsi-TOCSY and TOCSY) of metabolomics samples in a single experiment for the accurate and comprehensive identification and quantitation of metabolites. These new methods bring to bear the advantages of 2D NMR to metabolomics studies with larger cohorts of samples.

4.
Viruses ; 13(3)2021 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-33808906

RESUMEN

The heterogeneity of immune response to COVID-19 has been reported to correlate with disease severity and prognosis. While so, how the immune response progress along the period of viral RNA-shedding (VRS), which determines the infectiousness of disease, is yet to be elucidated. We aim to exhaustively evaluate the peripheral immune cells to expose the interplay of the immune system in uncomplicated COVID-19 cases with different VRS periods and dynamic changes of the immune cell profile in the prolonged cases. We prospectively recruited four uncomplicated COVID-19 patients and four healthy controls (HCs) and evaluated the immune cell profile throughout the disease course. Peripheral blood mononuclear cells (PBMCs) were collected and submitted to a multi-panel flowcytometric assay. CD19+-B cells were upregulated, while CD4, CD8, and NK cells were downregulated in prolonged VRS patients. Additionally, the pro-inflammatory-Th1 population showed downregulation, followed by improvement along the disease course, while the immunoregulatory cells showed upregulation with subsequent decline. COVID-19 patients with longer VRS expressed an immune profile comparable to those with severe disease, although they remained clinically stable. Further studies of immune signature in a larger cohort are warranted.

6.
Dis Markers ; 2021: 6643586, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33791044

RESUMEN

Purpose: To precisely quantify split glomerular filtration rate by Tc-99m-DTPA renal dynamic imaging and plasma clearance in order to increase its consistency among doctors. Methods: Tc-99m-DTPA renal dynamic imaging was performed according to the conventional radionuclide renal dynamic imaging by five double-blinded doctors independently and automatically calculated split GFR, namely, gGFR. Moreover, the conventional radionuclide renal dynamic imaging was assessed to only outline the kidney, blank background, and automatically calculated split GFR, gGFR'. The total GFR value of patients, tGFR, was obtained by the double-plasma method. According to the formula, Precise GFR (pGFR) = gGFR'/(gGFR' + gGFR') × tGFR. The precise GFR value of the divided kidney, pGFR, was calculated. The Kendall's W test was used to compare the consistency of gGFR and pGFR drawn by five physicians. Results: According to Kendall's W consistency test, Kendall's coefficient of concordance was 0.834, p = 0.0001 using conventional method. The same five doctors used blank background again and the same standard Gates method to draw the kidneys, which automatically calculated gGFR'. Using input formula, the pGFR was calculated and Kendall's W consistency test (Kendall's coefficient of concordance = 0.956, p = 0.0001). Conclusion: The combination of Tc-99m-DTPA renal dynamic imaging combined with the double-plasma method could achieve accurate split GFR, and because of the omission of influence factors, the consistency of pGFR obtained by different doctors using this method was significantly higher than that of conventional Tc-99m-DTPA renal dynamic imaging.

7.
Int J Pharm ; : 120553, 2021 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-33794325

RESUMEN

Pancreatic cancer (PC) is an aggressive form of cancer with dense stroma and immune-suppressive microenvironment, which are the major barriers for treatment. To address such barriers, this study aimed to develop a sequential receptor-mediated mixed-charge targeted delivery system for PC based on 2-(3-((S)-5-amino-1-carboxypentyl)-ureido) pentanedioate (ACUPA-) and triphenylphosphonium (TPP+) modified nanomicelles containing ingenol-3-mebutate (I3A), which was named ACUPA-/TPP+-I3A or ACUPA/TPP-I3A. ACUPA/TPP-I3A induced immunogenic cell death (ICD), which significantly increased the number of tumor-infiltrating T lymphocytes, activated adaptive immunity, and achieved superior survival time. I3A, a novel anticancer drug, could induce PC cell necrosis to release damage-associated molecular patterns, thereby activating adaptive immunity. With certain ratios of negatively (ACUPA-) and positively (TPP+) charged ligands, ACUPA/TPP-I3A acquired a negative charge in plasma (pH 7.4, to inhibit aggregation and uptake in the circulation) and was neutral in the acidic tumor microenvironment (pH 5.0-6.0, to overcome electrostatic hindrances and facilitate transcytosis). Furthermore, neovascular endothelium-specific ACUPA enabled rapid transcytosis of ACUPA/TPP-I3A across tumor vessel walls, entering into endosome/lysosomes (pH 4.5-5.0, its charge became positive and exhibited lysosome escape). Then, ACUPA/TPP-I3A selectively targeted mitochondria, which correlated with TPP-mediated effect. Finally, I3A was released to induce ICD that activated adaptive immunity and achieved superior survival time. Therefore, reshaping of the tumor microenvironment and potentiating antitumor immunity using ACUPA-/TPP+-I3A constituted a novel strategy to prolong the survival time.

8.
Mol Ther ; 2021 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-33794365

RESUMEN

Previously, we discovered that FOSL1 facilitates the metastasis of head and neck squamous cell carcinoma (HNSCC) cancer stem cells in a spontaneous mouse model. However, the molecular mechanisms remained unclear. Here, we demonstrated that FOSL1 serves as the dominate AP1 family member and is significantly upregulated in HNSCC tumor tissues and correlated with metastasis of HNSCC. Mechanistically, FOSL1 exerts its function in promoting tumorigenicity and metastasis predominantly via selective association with Mediators to establish super-enhancers (SEs) at a cohort of cancer stemness and pro-metastatic genes, such as SNAI2 and FOSL1 itself. Depletion of FOSL1 led to disruption of SEs and expression inhibition of these key oncogenes, which resulted in the suppression of tumor-initiation and metastasis. We also revealed that the abundance of FOSL1 is positively associated with the abundance of SNAI2 in HNSCC and the high expression of FOSL1 and SNAI2 levels are associated with short overall disease-free survival. Finally, the administration of the FOSL1 inhibitor, SR11302, significantly suppressed tumor growth and lymph node metastasis of HNSCC in a patient-derived-xenograft model. These findings indicate that FOSL1 is a master regulator that promotes the metastasis of HNSCC through a SE-driven transcription program that may represent an attractive target for therapeutic interventions.

9.
Cell Death Dis ; 12(4): 340, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33795657

RESUMEN

Osteoporosis is the most prevailing primary bone disease and a growing health care burden. The aim of this study was to clarify the functional roles and mechanisms of the circ-ITCH regulating osteogenic differentiation of osteoporosis. Circ-ITCH and yes-associated protein 1 (YAP1) levels were downregulated, but the miR-214 level was upregulated in osteoporotic mice and patients. Knockdown of circ-ITCH inhibited the alkaline phosphatase (ALP) activity, mineralized nodule formation, and expression of runt-related transcription factor 2 (RUNX2), osteopontin (OPN), and osteocalcin (OCN) during osteogenic induction. Furthermore, miR-214 was a target of circ-ITCH, knockdown of miR-214 could impede the regulatory effects of sh-circ-ITCH on osteogenic differentiation. Moreover, miR-214 suppressed hBMSCs osteogenic differentiation by downregulating YAP1. Finally, in vivo experiments indicated that overexpression of circ-ITCH could improve osteogenesis in ovariectomized mice. In conclusion, circ-ITCH upregulated YAP1 expression to promote osteogenic differentiation in osteoporosis via sponging miR-214. Circ-ITCH could act as a novel therapeutic target for osteoporosis.

10.
Inorg Chem ; 2021 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-33797226

RESUMEN

Developing high-performance and cost-efficient catalysts toward oxygen evolution reaction (OER) is an important but daunting task due to the sluggish kinetics hindered by the four-electron transfer process. Herein, an advanced class of ultralow Ru-doped NiCo-MOF hollow porous nanospheres (denoted as Ru@NiCo-MOF HPNs) has been reported in this work. Benefiting from the high porosity and large surface area of the metal-organic frameworks (MOFs) and optimized electronic properties by Ru doping, the as-prepared Ru@NiCo-MOF HPNs exhibit superior performance for water oxidation with the overpotential of only 284 mV to reach a current density of 10 mA·cm-2 in alkaline electrolyte, as well as a small Tafel slope of 78.8 mV·dec-1, outperforming the NiCo-MOF HPNs (358 mV) and commercial RuO2 catalyst (326 mV). The incorporation of Ru in NiCo-MOF HPNs enables a stable OER activity for at least 39 h. Moreover, we have probed the interaction between the content of Ru and OER performance, impressively, Ru@NiCo-MOF HPNs with 13.5 atom % Ru doping (denoted as Ru@NiCo-MOF-4) exhibited the highest OER activity with the excellent mass activity of 310 mA·mg-1 at an overpotential of 284 mV. Besides, a two-electrode cell with Ru@NiCo-MOF-4 as the anode and commercial Pt/C catalyst as the cathode also demonstrated outstanding electrocatalytic overall water splitting performance with a cell potential of merely 1.57 V to deliver a current density of 10 mA·cm-2.

11.
Biochim Biophys Acta Mol Cell Res ; 1868(6): 119016, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33744274

RESUMEN

Epithelial growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have been widely used in the clinical treatment of non-small cell lung cancer (NSCLC) patients with EGFR mutations. Previous studies have shown that Aurora kinase A (AURKA) is overexpressed in a broad spectrum of cancer cells, which can induce epithelial-mesenchymal transition (EMT) and contribute to the occurrence of acquired EGFR-TKI resistance. However, whether the inhibition of AURKA could overcome EGFR-TKI resistance or reverse the EMT in TKI-resistant NSCLC cells remains unclear. In the current study, we established three EGFR-TKI-resistant cell lines and analyzed their expression profiles by RNA sequencing. The results revealed that the EMT pathway is significantly upregulated in the three cell lines with EGFR-TKI resistance. The phosphorylation of AURKA at Thr 288 was also upregulated, suggesting that the activation of AURKA plays an important role in the occurrence of EGFR-TKI resistance. Interestingly, the AURKA inhibitor, alisertib treatment restored the susceptibility of resistant cells to EGFR-TKIs and partially reversed the EMT process, thereby reducing migration and invasion in EGFR-TKI-resistant cells. This study provides evidence that targeting AURKA signaling pathway by alisertib may be a novel approach for overcoming EGFR-TKI resistance and for the treatment of metastatic EGFR-TKIs in NSCLC patients.

12.
Biochim Biophys Acta Mol Basis Dis ; 1867(6): 166125, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33722746

RESUMEN

The uncontrolled abnormal intestinal immune responses play important role in eliciting inflammatory bowel disease (IBD), yet the molecular events regulating intestinal inflammation during IBD remain poorly understood. Here, we describe an endogenous, homeostatic pattern that controls inflammatory responses in experimental murine colitis. We show that Spink7 (serine peptidase inhibitor, kazal type 7), the ortholog of human SPINK7, is significantly upregulated in dextran sodium sulfate (DSS)-induced murine colitis model. Spink7-deficient mice showed highly susceptible to experimental colitis characterized by enhanced weight loss, shorter colon length, higher disease activity index and increased colonic tissue destruction. Bone marrow reconstitution experiments demonstrated that expression of Spink7 in the immune compartment makes main contribution to its protective role in colitis. What's more, neutrophils are the primary sources of Spink7 in experimental murine colitis. Loss of Spink7 leads to augmented productions of multiple chemokines and cytokines in colitis. In summary, this study identifies neutrophils-derived endogenous Spink7-mediated control of chemokines/cytokines production as a molecular mechanism contributing to inflammation resolution during colitis.

13.
Cancer Lett ; 507: 55-69, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33741424

RESUMEN

The tumor microenvironment has been recently reported to play a pivotal role in sustaining tumor cells survival and protecting them from immunotherapy and chemotherapy-induced death. It remains largely unknown how the specific signaling pathway exerts the tumor microenvironment in head and neck squamous cell carcinoma though previous studies have elucidated the regulatory mechanisms involve in tumor immune microenvironment, stromal cells, tumor angiogenesis and cancer stem cell. These components are responsible for tumor progression as well as anti-cancer therapy resistance, leading to rapid tumor growth and treatment failure. In this review, we focus on discussing the interaction between tumor cells and the surrounding components for better understanding of anti-cancer treatment ineffectiveness and its underlying molecular mechanisms.

14.
Oral Dis ; 2021 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-33772979

RESUMEN

OBJECTIVES: To identify independent factors for head and neck cancer (HNC) patients with carotid blowout syndrome (CBS) and construct a nomogram to predict risk of CBS preoperatively based on computed tomography angiography (CTA) imaging. SUBJECT AND METHODS: From January 2010 to July 2020, 73 HNC patients who had surgery in hospitalization and underwent CTA examination for head and neck region were included in this study. Vascular alterations and the relationship between carotid artery (CA) and tumor were evaluated in CTA. Clinical and CTA imaging features were distinguished by logistic regression analysis and used to perform receiver operating curve analysis. Nomogram was created to predict risk of CBS and assessed by concordance index (C-index) and calibration curve. RESULTS: Three independent risk factors were identified, including radical neck dissection, CA surrounded by tumor, and CA invaded by tumor without clear boundary. Area under curve of the combination of 3 variables was 0.836 (95% CI, 0.72-0.952, p < 0.001). The C-index of nomogram was 0.84 (95% CI, 0.73-0.94), and the calibration plot showed a good fitting between prediction and observation. CONCLUSIONS: We established a useful nomogram based on CTA imaging, which showed a satisfied efficacy for evaluating risk of CBS in HNC patients preoperatively.

15.
BMJ Open ; 11(3): e048012, 2021 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-33722876

RESUMEN

OBJECTIVES: The COVID-19 pandemic has overwhelmed health systems globally. With the increase of global migration, quantifying the health needs and key correlates of these outcomes is a global health priority. This study assessed migration characteristics, COVID-19 attitudes and the postmigration social environment as key correlates of depression, quality of life and alcohol misuse among international migrants in China. DESIGN: A nationwide cross-sectional online survey was conducted from 17 February and 1 March 2020. SETTING: Links to the online survey were disseminated by migrant-focused community-based organisations through WeChat. PARTICIPANTS: English speaking international migrants who met the inclusion criteria. Inclusion criteria were being born in a country outside of China, aged 18 years or over, cumulatively living in China for 1 month or more and staying in China between December 2019 and February 2020. OUTCOME MEASURES: Depression, quality of life and alcohol misuse. RESULTS: Regression models indicated that planning or considering leaving China due to COVID-19, lacking the confidence to protect themselves and not being confident that the epidemic would end soon was associated with greater depression, lower quality of life and greater levels of alcohol misuse. Worry about contracting COVID-19 and feeling helpless to prevent infection were associated with greater depression and lower quality of life. General perceived social support, and trust in Chinese people, institutions and systems were protective factors for depression and associated with higher reported quality of life. CONCLUSIONS: This study identifies key correlates that, if adequately addressed through public health outreach, may safeguard migrant well-being during a public health emergency. Trust in people and systems within the postmigration environment is an important consideration for future public health planning efforts.


Asunto(s)
Alcoholismo , Depresión , Calidad de Vida , Migrantes , Alcoholismo/epidemiología , China/epidemiología , Estudios Transversales , Depresión/epidemiología , Humanos , Pandemias , Encuestas y Cuestionarios
16.
Ying Yong Sheng Tai Xue Bao ; 32(3): 1005-1014, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33754567

RESUMEN

The establishment of protected areas is the bottom line of ecological security for promoting the construction of ecological civilization and supporting economic and social development, which is an important strategy to realize sustainable development and maintain ecological security. In order to reveal the large spatial process of protected areas and its influencing factors, we used the methods of nearest neighbor index, kernel density, and standard deviational ellipse to analyze the temporal-spatial variation characteristics of the protected areas in Guizhou Province from 2002 to 2017, as well as the influencing factors combined with geo-detectors. The results showed that, during the study period, the number, area, and types of protected areas in Guizhou Province showed a diversified and rapid development, forming a protected area system with nature reserves, forest parks and scenic spots as the main body and wetland parks, geoparks and natural heritage sites as the supplement. The spatial cohesion of protected areas was strengthened, the scope of spatial distribution was expanding, and the speed of spatial movement was declining, forming a spatial pattern dominated by the northeast-southwest direction and gradually stable. The coalescence process in protected areas was strongly influenced by topography and vegetation distribution. The protected areas tended to cluster in gentle terrain around rivers and mountains and in areas of concentrated vegetation. The spatial differentiation of protected areas was jointly affected by multiple factors at different levels. The explanatory power of different factors to the spatial differentiation of protected areas was different. Among them, the normalized difference vegetation index, areas of forest and highway mileage were the common main factors affecting the spatial differentiation of the number and area of protected areas, and the explanatory power of different factors was significantly consolidated after interaction, characterized as nonlinear or bi-factor enhancement.


Asunto(s)
Bosques , Ríos , China , Ecosistema
17.
Ying Yong Sheng Tai Xue Bao ; 32(3): 1119-1128, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33754580

RESUMEN

Sound is an important way of communication among organisms. The monitoring and analy-sis of biological sound is an emerging method to describe and evaluate biodiversity. This method does not invade or damage the natural environment. By recording ecological information through sound, it can effectively reflect the relevant characteristics of biodiversity. The sound-based exploration of biodiversity change has broadened the interdisciplinary approach and has been increasingly applied to ecological research. Here, we expounded on the main theoretical foundations and research methods of using acoustic monitoring to assess biodiversity. We introduced related research fields from two aspects, namely the biodiversity of vocal animals and the temporal and spatial diversity of soundscape. We presented examples of the application of acoustic monitoring to assess the impact of land-use change, climate change and urbanization on biodiversity. Finally, we proposed the future direction of development, and hope that the potential of sound surveys could be further explored to provide an effective reference for biodiversity monitoring and assessment.


Asunto(s)
Acústica , Biodiversidad , Animales , Conservación de los Recursos Naturales , Urbanización
18.
Huan Jing Ke Xue ; 42(4): 2003-2015, 2021 Apr 08.
Artículo en Chino | MEDLINE | ID: mdl-33742835

RESUMEN

In order to evaluate the potential ecological risk of heavy metals in the soil-crop system in the Xiong'an New District, the heavy metal contents and forms in wheat seed and root soil samples are analyzed, and the comprehensive pollution index (IPIN), potential ecological risk index (RI), bio-enrichment coefficient (BFC), risk assessment code (RAC), principal component analysis, and correlation analysis are used to assess the potential ecological risk of heavy metals and analyze their sources. The results indicate that the average content of Cd, Cu, Pb, and Zn in the root soil is significantly higher than the soil background value in Hebei province. The IPIN ranges from 0.2 to 5.18, 94.83% of the soil samples are in the safe and pollution-free grade, and the potential ecological risks of heavy metal are slight and moderate, accounting for 64.66% and 30.17%, respectively. Cd has the greatest potential ecological harm, followed by Hg, Cr, Ni, and Zn. All the heavy metal elements besides Cd in the root soil are dominated by the residual form, which accounts for 60%, and the bioactive form (ion-exchange and water-soluble state) of Cd accounts for 33.43%, indicating relatively high bio-availability. The risk assessment code can be ranked as Cd > Ni > Hg > As > Cu > Cr > Zn > Pb, and the risk of Cd is moderate, while other elements are of low or no risk. The leading potential source of heavy metals is human activity combined with the geological background. The migration and enrichment capability of the wheat seeds is in order from strong to weak of Zn > Cu > Cd > Hg > As > Ni > Pb > Cr, and the biological effective components of As, Cd, Pb, and Zn plays an substantial role in promoting the absorption of heavy metals. The content of heavy metals in the wheat seeds has a negative correlation with the soil pH, and the physical and chemical indices, such as OM and CEC, has bi-directional influence on the biological effective state of the heavy metals.


Asunto(s)
Metales Pesados , Contaminantes del Suelo , China , Monitoreo del Ambiente , Humanos , Metales Pesados/análisis , Medición de Riesgo , Suelo , Contaminantes del Suelo/análisis
19.
Sci Total Environ ; 764: 142901, 2021 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-33757249

RESUMEN

Aerobic methane (CH4) oxidation coupled to denitrification (AME-D) can not only mitigate CH4 emission into the atmosphere, but also potentially alleviate nitrogen pollution in surface waters and engineered ecosystems, and it has attracted substantial research interest. O2 concentration plays a key role in AME-D, yet little is understood about how it impacts microbial interactions. Here, we applied isotopically labeled K15NO3 and 13CH4 and metagenomic analyses to investigate the metabolic and microbial link of AME-D at different O2 levels. Among the four experimental O2 levels of 21%,10%, 5% and 2.5% and a CH4 concentration of 8% (i.e., the O2/CH4 ratios of 2.62, 1.26, 0.63 and 0.31), the highest NO3--N removal occurred in the AME-D system incubated at the O2 concentration of 10%. Methanol and acetate may serve as the trophic linkage between aerobic methanotrophs and denitrifers in the AME-D systems. Methylotrophs including Methylophilus, Methylovorus, Methyloversatilis and Methylotenera were abundant under the O2-sufficient condition with the O2 concentration of 21%, while denitrifiers such as Azoarcus, Thauera and Thiobacillus dominated in the O2-limited environment with the O2 concentration of 10%. The competition of denitrifiers and methylotrophs in the AME-D system for CH4-derived carbon, such as methanol and acetate, might be influenced by chemotactic responses. More methane-derived carbon flowed into methylotrophs under the O2-sufficient condition, while more methane-derived carbon was used for denitrification in the O2-limited environment. These findings can aid in evaluating the distribution and contribution of AME-D and in developing strategies for mitigating CH4 emission and nitrogen pollution in natural and engineered ecosystems.


Asunto(s)
Desnitrificación , Metano , Ecosistema , Metagenómica , Oxidación-Reducción
20.
Plant Mol Biol ; 2021 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-33694047

RESUMEN

KEY MESSAGE: TwPDR1, a PDR transporter from Tripterygium wilfordii Hook.f., was proved to efflux triptolide and its stability could be enhanced by A1033T mutation. Triptolide, an abietane-type diterpene in Tripterygium wilfordii Hook.f., possesses many pharmacological activities. However, triptolide is in short supply and very expensive because it is present at low amounts in natural plants and lack alternative production methods. Transporter engineering, which increases the extracellular secretion of secondary metabolites in in vitro culture systems, is an effective strategy in metabolic engineering but is rarely reported. In this study, TwPDR1, a pleiotropic drug resistance-type ATP binding cassette transporter, was identified as the best efflux pump candidate for diterpenoids through bioinformatics analysis. TwPDR1 was located in the plasma membrane, highly expressed in adventitious roots, and induced by methyl jasmonate. The triptolide efflux function of TwPDR1 was confirmed by transient expression in tobacco BY-2 cells and by downregulation via RNA interference in the native host. However, the overexpression of TwPDR1 had a limited effect on the secretion of triptolide. As shown by previous studies, a single amino acid mutation might increase the abundance of TwPDR1 by increasing protein stability. We identified the A1033 residue in TwPDR1 by sequence alignment and confirmed that A1033T mutation could increase the expression of TwPDR1 and result in the higher release ratio of triptolide (78.8%) of the mutants than that of control (60.1%). The identification and functional characterization of TwPDR1 will not only provide candidate gene material for the metabolic engineering of triptolide but also guide other transporter engineering researches in the future.

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