Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 48
Filter
Add more filters











Publication year range
1.
Nano Lett ; 24(34): 10650-10655, 2024 Aug 28.
Article in English | MEDLINE | ID: mdl-39158094

ABSTRACT

In situ characterizations of charge injection dynamics, equilibrated concentration, and electric field distributions shed light on the critical mechanisms of quantum dot light-emitting diodes (QD-LEDs). In this work, we developed electrically excited transient absorption spectroscopy, which can provide the above key information, to investigate the efficiency roll-off of QD-LEDs. We found that the average electron populations per QD are low when QD-LEDs exhibit efficiency roll-off, excluding Auger recombination as the main cause. We also revealed that the weak electrical field inside the QD layer under forward biases has a negligible impact on the efficiency. Interestingly, we found that as the voltage increases the electron concentration in the QD layer saturates at very low levels. When combined with the concomitant efficiency roll-off, we propose electron leakage is the main loss at elevated driving voltages. We further demonstrate that increasing the electron confinement potential with the ZnS shell enables us to efficiently mitigate the efficiency roll-off.

2.
Nat Commun ; 15(1): 6334, 2024 Jul 27.
Article in English | MEDLINE | ID: mdl-39068151

ABSTRACT

High-energy exciton emission could allow single-component multi-colour display or white light-emitting diodes. However, the thermal relaxation of high-energy excitons is much faster than the photon emission of them, making them non-emissive. Here, we report quantum dots with light hole-heavy hole splitting exhibiting strong high-energy exciton electroluminescence from high-lying light holes, opening a gate for high-performance multi-colour light sources. The high-energy electroluminescence can reach 44.5% of the band-edge heavy-hole exciton emission at an electron flux density Φe of 0.71 × 1019 s-1 cm-2 - 600 times lower than the photon flux density Φp (4.3 × 1021 s-1 cm-2) required for the similar ratio. Our simulation and experimental results suggest that the oscillator strength of heavy holes reduces more than that of light holes under electric fields. We attribute this as the main reason for strong light-hole electroluminescence. We observe this phenomenon in both CdxZn1-xSe-ZnS and CdSe-CdS core-shell quantum dots exhibiting large light hole-heavy hole splittings.

3.
Nat Commun ; 15(1): 5578, 2024 Jul 03.
Article in English | MEDLINE | ID: mdl-38956103

ABSTRACT

Diatoms often outnumber other eukaryotic algae in the oceans, especially in coastal environments characterized by frequent fluctuations in light intensity. The identities and operational mechanisms of regulatory factors governing diatom acclimation to high light stress remain largely elusive. Here, we identified the AUREO1c protein from the coastal diatom Phaeodactylum tricornutum as a crucial regulator of non-photochemical quenching (NPQ), a photoprotective mechanism that dissipates excess energy as heat. AUREO1c detects light stress using a light-oxygen-voltage (LOV) domain and directly activates the expression of target genes, including LI818 genes that encode NPQ effector proteins, via its bZIP DNA-binding domain. In comparison to a kinase-mediated pathway reported in the freshwater green alga Chlamydomonas reinhardtii, the AUREO1c pathway exhibits a faster response and enables accumulation of LI818 transcript and protein levels to comparable degrees between continuous high-light and fluctuating-light treatments. We propose that the AUREO1c-LI818 pathway contributes to the resilience of diatoms under dynamic light conditions.


Subject(s)
Acclimatization , Diatoms , Light , Diatoms/metabolism , Diatoms/genetics , Diatoms/radiation effects , Chlamydomonas reinhardtii/metabolism , Chlamydomonas reinhardtii/genetics , Chlamydomonas reinhardtii/radiation effects , Algal Proteins/metabolism , Algal Proteins/genetics , Gene Expression Regulation/radiation effects
4.
Sci Rep ; 14(1): 13661, 2024 06 13.
Article in English | MEDLINE | ID: mdl-38871732

ABSTRACT

Over the past decades, the immune responses have been suspected of participating in the mechanisms for epilepsy. To assess the immune related pathway in temporal lobe epilepsy (TLE), we explored the altered immune pathways in TLE patients with and without hippocampal sclerosis (HS). We analyzed RNA-seq data from 3 TLE-HS and 3 TLE-nonHS patients, including identification of differentially expressed RNA, function pathway enrichment, the protein-protein interaction network and construction of ceRNA regulatory network. We illustrated the immune related landscape of molecules and pathways on human TLE-HS. Also, we identified several differential immune related genes like HSP90AA1 and SOD1 in TLE-HS patients. Further ceRNA regulatory network analysis found SOX2-OT connected to miR-671-5p and upregulated the target gene SPP1 in TLE-HS patients. Also, we identified both SOX2-OT and SPP1 were significantly upregulated in five different databases including TLE-HS patients and animal models. Our findings established the first immune related genes and possible regulatory pathways in TLE-HS patients and animal models, which provided a novel insight into disease pathogenesis in both patients and animal models. The immune related SOX2-OT/miR-671-5p/SPP1 axis may be the potential therapeutic target for TLE-HS.


Subject(s)
Epilepsy, Temporal Lobe , Gene Regulatory Networks , Hippocampal Sclerosis , MicroRNAs , SOXB1 Transcription Factors , Adult , Animals , Female , Humans , Male , Epilepsy, Temporal Lobe/genetics , Epilepsy, Temporal Lobe/immunology , Epilepsy, Temporal Lobe/physiopathology , Gene Expression Profiling , Hippocampal Sclerosis/immunology , Hippocampal Sclerosis/physiopathology , MicroRNAs/genetics , MicroRNAs/metabolism , Osteopontin/genetics , Osteopontin/metabolism , Protein Interaction Maps , SOXB1 Transcription Factors/genetics , SOXB1 Transcription Factors/metabolism
5.
J Colloid Interface Sci ; 662: 1005-1015, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38387362

ABSTRACT

A novel strategy for better catalytic performance in terms of precisely tuning the metal atom number of active centers is gradually getting attention. In this paper, the Co atom pair sites on N-doped porous carbon was engineered. The binuclear Co2 site structure was identified by aberration-corrected scanning transmission electron microscopy and X-ray absorption spectroscopy. As expected, the Co2NC display an outstanding Fenton-like catalysis activity in tetracycline degradation with turnover frequency exceeding 0.91 min-1 that is approximately 4 times higher than the conventional CoN4 site. The EPR tests indicated that the ROS strength stimulated by the binuclear site was much stronger than that of single site. Theoretical density functional theory calculations reveal that the optimized adsorption configuration is the O1 of peroxymonosulfate (PMS) interacting with two Co atoms, leading to stronger interaction effect and electron transfer for PMS comparing to single atom sites.

6.
Clin J Gastroenterol ; 16(6): 793-802, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37740882

ABSTRACT

The clinical benefits and safety of hepatic arterial infusion chemotherapy (HAIC) combined with sorafenib versus sorafenib alone for advanced HCC are inconsistent in clinical studies. This meta-analysis aims to evaluate the effectiveness and safety of HAIC combined with sorafenib versus sorafenib alone for advanced hepatocellular carcinoma (HCC). We searched the database up to March 1, 2023, for studies evaluating the effectiveness and safety of HAIC combined with sorafenib versus sorafenib alone for advanced HCC. This study was registered in PROSPERO (CRD42022323712). Outcomes included overall survival (OS), progression-free survival (PFS), objective response rate (ORR), diseases control rate (DCR), and adverse effects (AEs). The hazard ratio (HR) and odd ratio (OR) with 95% confidence intervals (CI) were used to measure the pooled effect. Six studies with 318 patients in the combination group and 338 patients in the control group were included. Meta-analysis showed that HAIC combined with sorafenib significantly improves OS compared with sorafenib alone (HR = 9.70, 95% CI 4.52-20.82] and HAIC combined with sorafenib significantly improves PFS compared with sorafenib alone (HR = 9.48, 95% CI 4.47-20.13). Besides, HAIC combined with sorafenib did not show significantly advantage of DCR rate (OR = 1.85, 95% CI 0.93-3.69), but associated with higher rates of ORR compared with sorafenib alone (OR = 9.85, 95% CI 3.05-31.85). HAIC combined with sorafenib can achieve a better effect and survival benefits than sorafenib alone in patients with advanced HCC, but the limitation should be treated with cautions.


Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , Humans , Carcinoma, Hepatocellular/drug therapy , Carcinoma, Hepatocellular/pathology , Sorafenib/adverse effects , Liver Neoplasms/drug therapy , Liver Neoplasms/pathology , Treatment Outcome , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Infusions, Intra-Arterial/adverse effects
7.
Nat Nanotechnol ; 18(10): 1168-1174, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37474685

ABSTRACT

Minimizing heat accumulation is essential to prolonging the operational lifetime of quantum dot light-emitting diodes (QD-LEDs). Reducing heat generation at the source is the ideal solution, which requires high brightness and quantum efficiency at low driving voltages. Here we propose to enhance the brightness of QD-LEDs at low driving voltages by using a monolayer of large QDs to reduce the packing number in the emitting layer. This strategy allows us to achieve a higher charge population per QD for a given number of charges without charge leakage, enabling enhanced quasi-Fermi-level splitting and brightness at low driving voltage. Due to the minimized heat generation, these LEDs show a high power conversion efficiency of 23% and a T95 operation lifetime (the time for the luminance to decrease to 95% of the initial value) of more than 48,000 h at 1,000 cd m-2.

8.
Proc Natl Acad Sci U S A ; 120(9): e2219952120, 2023 02 28.
Article in English | MEDLINE | ID: mdl-36802416

ABSTRACT

Social behavior starts with dynamic approach prior to the final consummation. The flexible processes ensure mutual feedback across social brains to transmit signals. However, how the brain responds to the initial social stimuli precisely to elicit timed behaviors remains elusive. Here, by using real-time calcium recording, we identify the abnormalities of EphB2 mutant with autism-associated Q858X mutation in processing long-range approach and accurate activity of prefrontal cortex (dmPFC). The EphB2-dependent dmPFC activation precedes the behavioral onset and is actively associated with subsequent social action with the partner. Furthermore, we find that partner dmPFC activity is responsive coordinately to the approaching WT mouse rather than Q858X mutant mouse, and the social defects caused by the mutation are rescued by synchro-optogenetic activation in dmPFC of paired social partners. These results thus reveal that EphB2 sustains neuronal activation in the dmPFC that is essential for the proactive modulation of social approach to initial social interaction.


Subject(s)
Prefrontal Cortex , Receptor, EphB2 , Social Behavior , Animals , Mice , Brain , Neurons/physiology , Prefrontal Cortex/physiology , Receptor, EphB2/genetics , Receptor, EphB2/physiology
9.
Nanoscale ; 15(8): 3585-3593, 2023 Feb 23.
Article in English | MEDLINE | ID: mdl-36727444

ABSTRACT

As the emitters of quantum dots (QDs) light-emitting diodes (QLEDs), QDs, which are responsible for the charge injection, charge transportation, and especially exciton recombination, play a significant role in QLEDs. With the crucial advances made in QDs, such as the advancement of synthetic methods and the understanding of luminescence mechanisms, QLEDs also demonstrate a dramatic improvement. Until now, efficiencies of 30.9%, 28.7% and 21.9% have been achieved in red, green and blue devices, respectively. However, in QLEDs, some issues are still to be solved, such as the imbalance of charge injection and exciton quenching processes (defect-assisted recombination, Auger recombination, energy transfer and exciton dissociation under a high electric field). In this review, we will provide an overview of recent advances in the study and understanding of the working mechanism of QLEDs and the exciton quenching mechanism of QDs in devices. Particular emphasis is placed on improving charge injection and suppressing exciton quenching. An in-depth understanding of this progress may help develop guidelines to direct QLED development.

10.
Acta Clin Belg ; 78(2): 171-179, 2023 Apr.
Article in English | MEDLINE | ID: mdl-35587164

ABSTRACT

BACKGROUND: We carried out a systematic review and meta-analysis to assess the safety and effectiveness of hepatic arterial infusion chemotherapy (HAIC) compared with transarterial chemoembolization (TACE) for patients with unresectable hepatocellular carcinoma (uHCC). METHODS: Eligible studies were searched by MEDLINE, the Cochrane Library, Embase, and Web of Science from January 1995 to January 2022, investigating eligible literature comparing HAIC and TACE for patients with HCC. The main outcome measures included progression-free survival (PFS), overall survival (OS), adverse events (AEs), objective response rate (ORR), and diseases control rate (DCR). RESULTS: Eight literature and 1028 patients were enrolled in this meta-analysis. The pooled PFS, OS, ORR, and DCR were HR = 0.89 (95% CI, 0.81-0.98), HR = 0.84 (95% CI, 0.75-0.93), OR = 2.77 (95% CI, 2.01-3.80), and OR = 4.64 (95% CI, 2.40-8.99), respectively. The adverse events of HAIC were lower than TACE. CONCLUSION: Our meta-analysis revealed that HAIC can achieve a better effect and survival benefits than TACE in patients with uHCC.


Subject(s)
Carcinoma, Hepatocellular , Chemoembolization, Therapeutic , Liver Neoplasms , Humans , Carcinoma, Hepatocellular/drug therapy , Carcinoma, Hepatocellular/pathology , Liver Neoplasms/drug therapy , Liver Neoplasms/pathology , Chemoembolization, Therapeutic/adverse effects , Infusions, Intra-Arterial , Treatment Outcome
11.
Environ Geochem Health ; 45(6): 3805-3816, 2023 Jun.
Article in English | MEDLINE | ID: mdl-36577857

ABSTRACT

Organophosphate esters (OPEs) are emerging pollutants. Currently, research on OPEs in tree rings is still limited. In this study, tree rings of five arbor species from Sichuan Province, China, were sampled to study the occurrence and distribution of six OPEs, which were quantitatively analyzed by gas chromatography-mass spectrometry (GC-MS). The total concentrations of OPEs in all samples ranged from 189.79 (Fir species) to 341.23 ng/g (Toona sinensis), with average concentration of 284.77 ± 46.66 ng/g. So, arbor could be used as good passive samplers for OPEs. The levels of OPEs among five arbor species showed no significant difference (p = 0.668 > 0.05), suggesting that the pollution status of OPEs in a region or country could be roughly assessed by any arbor tree species. In this study area, tris(2-butoxyethyl) phosphate (TBEP) was the dominant OPEs followed by tri(2-chloroethyl) phosphate (TCEP). Tris(2-ethylhexyl) phosphate (TEHP) and tri-n-butyl phosphate (TnBP) showed relatively stable concentrations in each arbor species, while the other four OPEs including TBEP, triphenyl phosphate (TPhP), tri(chloropropyl) phosphate (TCPP) and TCEP had significantly different concentrations. Interestingly, the absorption and accumulation of OPEs by tree rings of arbor species were quite different from that of inorganic elements reported by other studies.


Subject(s)
Environmental Monitoring , Flame Retardants , Environmental Monitoring/methods , Esters/analysis , Flame Retardants/analysis , Organophosphates/analysis , China , Phosphates/analysis
12.
Huan Jing Ke Xue ; 43(11): 4992-4999, 2022 Nov 08.
Article in Chinese | MEDLINE | ID: mdl-36437071

ABSTRACT

As a type of emerging pollutant of concern, organophosphate esters (OPEs) have posed a moderate risk to the remote Antarctic waters. Triphenyl phosphate (TPHP) is a common type of OPEs in water, which has been proven to have toxic effects, bioaccumulation, and amplification effects and pose a great threat to the environment and human health. Fourier transform infrared spectroscopy (FT-IR) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) were used to investigate the degradation process of TPHP in three advanced oxidation processes (UV-AOPs), including ultraviolet-hydrogen peroxide (UV-H2O2), ultraviolet-titanium dioxide (UV-TiO2), and ultraviolet-persulfate (UV-PS) systems. This was the first instance of using FT-IR for the online observation of the change in infrared characteristic peaks in the degradation process of TPHP, and its degradation reaction kinetics, photodegradation products, and degradation pathways were analyzed. The results showed that TPHP could be effectively degraded under UV-H2O2, UV-TiO2, and UV-PS systems, and the photodegradation half-lives were 74, 150, and 89 min, respectively. The UV-H2O2 system had the best degradation effect on TPHP. Additionally, the degradation reactions of TPHP in three systems conformed to the first-order kinetics. When the concentration of H2O2 was 0-0.097 mol·L-1, the increase in H2O2 concentration promoted the degradation of TPHP, and when the concentration of TiO2 was 0-0.013 mol·L-1, the increase in TiO2 concentration promoted the degradation of TPHP. The photodegradation pathway of TPHP mainly included the P-O-C bond breaking, the C-H bond cleavage of the benzene ring structure and the hydrolysis reaction of TPHP. The UV-H2O2 system was used to degrade OPEs in the environmental water of Chengdu, and it was found that the removal rate of TPHP was 66% when the water samples of the park landscape water were degraded for 60 min.


Subject(s)
Hydrogen Peroxide , Water , Humans , Hydrogen Peroxide/chemistry , Chromatography, Liquid , Spectroscopy, Fourier Transform Infrared , Ultraviolet Rays , Tandem Mass Spectrometry , Organophosphates
13.
World J Clin Cases ; 10(31): 11652-11657, 2022 Nov 06.
Article in English | MEDLINE | ID: mdl-36387829

ABSTRACT

BACKGROUND: Colonoscopy has become a routine physical examination as people's health awareness has increased. Polyethylene glycol (PEG) is greatly used in bowel preparation before colonoscopy due to its price and safety advantages. Septic shock after colonoscopy with PEG preparation is extremely rare, with only very few cases in critically ill patients. Herein, we describe a case of septic shock in a healthy young adult immediately following colonoscopy with PEG preparation. CASE SUMMARY: A 33-year-old young adult presented to our hospital for colonoscopy with PEG bowel preparation due to recurrent diarrhea for 7 years. The male's previous physical examination showed no abnormal indicators, and colonoscopy results were normal; however, he exhibited septic shock and markedly elevated white blood cell, C-reactive protein, and procalcitonin levels on the second day after colonoscopy. Immediate resuscitation and intensive care with appropriate antibiotics improved his condition. However, the blood and stool cultures did not detect the pathogen. CONCLUSION: Septic shock after colonoscopy is rare, especially in young adults. The authors considered the possibility of opportunistic infections after PEG bowel preparation, and clinicians should monitor patients for the possibility of such complications.

14.
Front Immunol ; 13: 1021634, 2022.
Article in English | MEDLINE | ID: mdl-36189262

ABSTRACT

Myeloid-derived suppressor cells (MDSCs) are a group of bone marrow derived heterogeneous cells, which is known for their immunosuppressive functions especially in tumors. Recently, MDSCs have receiving increasing attention in pathological conditions like infection, inflammation and autoimmune diseases. Inflammatory bowel diseases (IBD) are a series of immune-dysfunctional autoimmune diseases characterized by relapsing intestinal inflammation. The role of MDSCs in IBD remains controversial. Although most studies in vitro demonstrated its anti-inflammatory effects by inhibiting the proliferation and function of T cells, it was reported that MDSCs failed to relieve inflammation but even promoted inflammatory responses in experimental IBD. Here we summarize recent insights into the role of MDSCs in the development of IBD and the potential of MDSCs-targeted therapy.


Subject(s)
Autoimmune Diseases , Inflammatory Bowel Diseases , Myeloid-Derived Suppressor Cells , Anti-Inflammatory Agents , Autoimmune Diseases/pathology , Humans , Inflammation
15.
Huan Jing Ke Xue ; 43(9): 4522-4531, 2022 Sep 08.
Article in Chinese | MEDLINE | ID: mdl-36096593

ABSTRACT

Forty-eight surface water samples were analyzed using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) in order to study the pollution characteristics and source apportionment of per- and polyfluoroalkylated substances (PFASs) in the Tuojiang River. The results showed that ΣPFASs in the Tuojiang River ranged from 12.5-3789 ng·L-1, and perfluorooctanoic acid (PFOA) was the predominant PFAS, with a concentration of 9.97-3764 ng·L-1 (73.6%-99.8%), suggesting that legacy PFASs were still the dominant PFASs in the Tuojiang River. The most frequently detected emerging PFASs was 9-chlorohexadecafluoro-3-oxanonane-1-sulfonate (F-53B), with a detection frequency of 100%, suggesting the wide use of F-53B in the Tuojiang River. Sodium 1H, 1H, 2H, 2H-perfluorooctane sulfonate (6:2 FTS) displayed the highest concentration among all emerging PFASs[nd-27.3 ng·L-1, mean:(9.12±7.70) ng·L-1], and the concentrations were at the higher levels compared to those in other rivers around the world. In addition, ΣPFASs showed the highest concentrations of ΣPFASs at the fluorochemical manufacturing park (FMP), followed by those in the Luzhou section (in the lower reaches of the Tuojiang River), indicating that the emission of FMP and human daily production activities were the main influencing factors of PFASs pollution in the Tuojiang River. The estimated flux of PFASs from the Tuojiang River to the Yangtze River was 353 kg·a-1, and PFOA displayed the greatest mass loading (348 kg·a-1), which could provide the basic data for controlling PFASs in the Tuojiang River.


Subject(s)
Fluorocarbons , Water Pollutants, Chemical , Chromatography, Liquid , Environmental Monitoring , Fluorocarbons/analysis , Humans , Rivers/chemistry , Tandem Mass Spectrometry , Water Pollutants, Chemical/analysis
16.
Inorg Chem ; 61(30): 11932-11938, 2022 Aug 01.
Article in English | MEDLINE | ID: mdl-35848216

ABSTRACT

The properties of supports have a significant effect on the activity of noble metal single atoms. In this work, Co-doped CeO2-supported single-atom Pt catalysts (Pt1/Co-CeO2) have been acquired by a synchronous pyrolysis/deposition route and demonstrated to promote low-temperature oxidation of CO. Revealed by a model reaction of 1% CO + 1% O2 + 98% He at a space velocity of 12,000 mL/gcat/h, CO conversion (100 °C) acquired on a (0.5% Pt)/(10% Co-CeO2) catalyst (36.6%) was 3.6 and 4.9 times those of 0.5% Pt/CeO2 (10.0%) and 10% Co-CeO2 (7.4%) catalysts and 2.1 times that of their conversion sum (17.4%), confirming the positive role of the Co dopant in boosting the low-temperature oxidation of CO. The consistent results are also verified in the comparison of Pt1/Co-ZnO with Pt1/ZnO and Pt1/Co-Al2O3 with Pt1/Al2O3. In addition, the activity of single-atom Pt1/Co-CeO2 catalysts can be facilely modified by changing the loading of Pt and/or doping amount of Co. These reasonable data will provide a methodology to access more applicable catalysts for CO oxidation at low temperature.

17.
Nat Prod Res ; 36(18): 4605-4613, 2022 Sep.
Article in English | MEDLINE | ID: mdl-34736358

ABSTRACT

Four new depsidones, mollicellins V-Y (1-4), together with eight known depsidones (5-12) were isolated from the endophytic fungus, Chaetomium brasiliense, detached from stems of Thai rice. Their structures were determined by extensive spectroscopic methods. Mollicellins X, H, and F (3, 8 and 10) showed potent cytotoxicity against the human oral epidermoid carcinoma (KB) cell line, and mollicellin F (10) also showed a potent cytotoxicity against the human hepatocellular carcinoma (HepG2) cell line. Besides, mollicellin B (11) exhibited cytotoxicity against the colorectal adenocarcinoma (HT-29) cell line. Moreover, most of the isolated depsidones displayed potent antibacterial activity against Gram-positive bacteria, Bacillus cereus and Bacillus subtilis, and several of them showed moderate activity against Methicillin-resistant Staphylococcus aureus (MRSA) and clinical isolates of S. aureus. In addition, a few of them also showed moderate activity against a Gram-negative bacteria Pseudomonas aeruginosa.


Subject(s)
Antineoplastic Agents , Chaetomium , Methicillin-Resistant Staphylococcus aureus , Oryza , Anti-Bacterial Agents/chemistry , Antineoplastic Agents/chemistry , Chaetomium/chemistry , Depsides , Humans , Lactones , Microbial Sensitivity Tests , Molecular Structure , Sordariales , Staphylococcus aureus , Thailand
18.
Arch Environ Contam Toxicol ; 82(1): 11-20, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34709437

ABSTRACT

Human activities have led to the release of organophosphate esters (OPEs) into the environment. This study aims to investigate the levels and partitioning of OPEs in surface water, suspended particulate matter (SPM) and sediments of landscape waters across eleven parks in the city of Chengdu, a megacity in Southwest China. The average concentration of Σ6OPEs in the SPM samples (median: 2.94 × 103 ng/L, 6.88 × 104 ng/g dry weight) was 1-3 orders of magnitude higher than that in the surface water (median: 359 ng/L) and sediment (median: 82.8 ng/g) samples. Tri-n-butyl phosphate (TnBP), tris-(2-chloroethyl)-phosphate (TCEP) and trichloropropyl phosphate (TCIPP) were the primary OPE pollutants in the surface water and SPM samples, while TnBP, tris-(2-butoxyethyl) phosphate (TBEP) and tris-(2-ethylhexyl) phosphate (TEHP) predominated the sediment samples. The higher log Koc values of OPEs in park landscape water bodies estimated in the present study relative to previous studies could be explained by the environmental conditions, such as the sources of the inputs and the hydraulic retention times in these surface waters.


Subject(s)
Flame Retardants , China , Environmental Monitoring , Esters , Flame Retardants/analysis , Humans , Organophosphates , Water , Wetlands
19.
Environ Sci Pollut Res Int ; 29(17): 25892-25901, 2022 Apr.
Article in English | MEDLINE | ID: mdl-34850344

ABSTRACT

Effluent from wastewater treatment plants (WWTP) is an important source of organophosphate esters (OPEs) in the receiving rivers. In this paper, the concentration and distribution of seven OPEs in the water samples were determined, and the discharge was estimated. The results showed that the total removal rate of Σ7OPEs in water phase in WWTP was 57.2%. The average concentrations of Σ7OPEs in influent and effluent of the WWTP during rainy period were 3956.1 ± 1897.3 ng/L and 1461.9 ± 846.3 ng/L, respectively, which were about 4 times larger than those in influent water (978.2 ± 166.5 ng/L) and effluent (418.3 ± 12.0 ng/L) during non-rainy period, indicating that rainfall has a marked impact on the load of OPEs in WWTP and the receiving water. It was estimated that the average daily discharge of Σ7OPEs in the effluent of WWTP was 157.9 g, and the daily per capita contribution of the population in the area to the OPEs in the influent was 0.414 mg. During the shift of labour-intensive manufacturing from the coastal developed areas to inland regions, OPEs were widely used and produced in Southwest China. The total amount of OPEs emissions and its control should be taken into consideration.


Subject(s)
Flame Retardants , Water Pollutants, Chemical , Water Purification , China , Environmental Monitoring/methods , Esters , Flame Retardants/analysis , Organophosphates , Wastewater , Water , Water Pollutants, Chemical/analysis
20.
Plant Physiol ; 188(3): 1496-1506, 2022 03 04.
Article in English | MEDLINE | ID: mdl-34893909

ABSTRACT

Tanshinone ⅡA (TⅡA), a diterpene quinone with a furan ring, is a bioactive compound found in the medicinal herb redroot sage (Salvia miltiorrhiza Bunge), in which both furan and dihydrofuran analogs are present in abundance. Progress has been made recently in elucidating the tanshinone biosynthetic pathway, including heterocyclization of the dihydrofuran D-ring by cytochrome P450s; however, dehydrogenation of dihydrofuran to furan, a key step of furan ring formation, remains uncharacterized. Here, by differential transcriptome mining, we identified six 2-oxoglutarate-dependent dioxygenase (2-ODD) genes whose expressions corresponded to tanshinone biosynthesis. We showed that Sm2-ODD14 acts as a dehydrogenase catalyzing the furan ring aromatization. In vitro Sm2-ODD14 converted cryptotanshinone to TⅡA and thus was designated TⅡA synthase (SmTⅡAS). Furthermore, SmTⅡAS showed a strict substrate specificity, and repression of SmTⅡAS expression in hairy root by RNAi led to increased accumulation of total dihydrofuran-tanshinones and decreased production of furan-tanshinones. We conclude that SmTⅡAS controls the metabolite flux from dihydrofuran- to furan-tanshinones, which influences medicinal properties of S. miltiorrhiza.


Subject(s)
Dioxygenases/genetics , Dioxygenases/metabolism , Diterpenes/metabolism , Furans/metabolism , Plants, Medicinal/metabolism , Salvia miltiorrhiza/genetics , Salvia miltiorrhiza/metabolism , Biosynthetic Pathways , Gene Expression Regulation, Plant , Genes, Plant , Plant Roots/metabolism
SELECTION OF CITATIONS
SEARCH DETAIL