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1.
N Engl J Med ; 390(3): 230-241, 2024 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-38231624

RESUMO

BACKGROUND: Simnotrelvir is an oral 3-chymotrypsin-like protease inhibitor that has been found to have in vitro activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and potential efficacy in a phase 1B trial. METHODS: In this phase 2-3, double-blind, randomized, placebo-controlled trial, we assigned patients who had mild-to-moderate coronavirus disease 2019 (Covid-19) and onset of symptoms within the past 3 days in a 1:1 ratio to receive 750 mg of simnotrelvir plus 100 mg of ritonavir or placebo twice daily for 5 days. The primary efficacy end point was the time to sustained resolution of symptoms, defined as the absence of 11 Covid-19-related symptoms for 2 consecutive days. Safety and changes in viral load were also assessed. RESULTS: A total of 1208 patients were enrolled at 35 sites in China; 603 were assigned to receive simnotrelvir and 605 to receive placebo. Among patients in the modified intention-to-treat population who received the first dose of trial drug or placebo within 72 hours after symptom onset, the time to sustained resolution of Covid-19 symptoms was significantly shorter in the simnotrelvir group than in the placebo group (180.1 hours [95% confidence interval {CI}, 162.1 to 201.6] vs. 216.0 hours [95% CI, 203.4 to 228.1]; median difference, -35.8 hours [95% CI, -60.1 to -12.4]; P = 0.006 by Peto-Prentice test). On day 5, the decrease in viral load from baseline was greater in the simnotrelvir group than in the placebo group (mean difference [±SE], -1.51±0.14 log10 copies per milliliter; 95% CI, -1.79 to -1.24). The incidence of adverse events during treatment was higher in the simnotrelvir group than in the placebo group (29.0% vs. 21.6%). Most adverse events were mild or moderate. CONCLUSIONS: Early administration of simnotrelvir plus ritonavir shortened the time to the resolution of symptoms among adult patients with Covid-19, without evident safety concerns. (Funded by Jiangsu Simcere Pharmaceutical; ClinicalTrials.gov number, NCT05506176.).


Assuntos
COVID-19 , Inibidores de Protease de Coronavírus , Adulto , Humanos , Administração Oral , Antivirais/administração & dosagem , Antivirais/efeitos adversos , Antivirais/farmacologia , Antivirais/uso terapêutico , China , Proteínas M de Coronavírus/antagonistas & inibidores , Proteínas M de Coronavírus/metabolismo , Inibidores de Protease de Coronavírus/administração & dosagem , Inibidores de Protease de Coronavírus/efeitos adversos , Inibidores de Protease de Coronavírus/farmacologia , Inibidores de Protease de Coronavírus/uso terapêutico , COVID-19/metabolismo , COVID-19/terapia , Tratamento Farmacológico da COVID-19/métodos , Método Duplo-Cego , Ritonavir/administração & dosagem , Ritonavir/efeitos adversos , Ritonavir/farmacologia , Ritonavir/uso terapêutico , SARS-CoV-2/efeitos dos fármacos , Fatores de Tempo , Combinação de Medicamentos
2.
Environ Sci Technol ; 58(1): 510-521, 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38100654

RESUMO

Fluorinated liquid crystal monomers (FLCMs) have been suggested as emerging contaminants, raising global concern due to their frequent occurrence, potential toxic effects, and endurance capacity in the environment. However, the environmental fate of the FLCMs remains unknown. To fill this knowledge gap, we investigated the aerobic microbial transformation mechanisms of an important FLCM, 4-[difluoro(3,4,5-trifluorophenoxy)methyl]-3, 5-difluoro-4'-propylbiphenyl (DTMDPB), using an enrichment culture termed as BG1. Our findings revealed that 67.5 ± 2.1% of the initially added DTMDPB was transformed in 10 days under optimal conditions. A total of 14 microbial transformation products obtained due to a series of reactions (e.g., reductive defluorination, ether bond cleavage, demethylation, oxidative hydroxylation and aromatic ring opening, sulfonation, glucuronidation, O-methylation, and thiolation) were identified. Consortium BG1 harbored essential genes that could transform DTMDPB, such as dehalogenation-related genes [e.g., glutathione S-transferase gene (GST), 2-haloacid dehalogenase gene (2-HAD), nrdB, nuoC, and nuoD]; hydroxylating-related genes hcaC, ubiH, and COQ7; aromatic ring opening-related genes ligB and catE; and methyltransferase genes ubiE and ubiG. Two DTMDPB-degrading strains were isolated, which are affiliated with the genus Sphingopyxis and Agromyces. This study provides a novel insight into the microbial transformation of FLCMs. The findings of this study have important implications for the development of bioremediation strategies aimed at addressing sites contaminated with FLCMs.


Assuntos
Cristais Líquidos , Biodegradação Ambiental , Hidroxilação
3.
Artigo em Inglês | MEDLINE | ID: mdl-38960394

RESUMO

INTRODUCTION: Antithrombin (AT) deficiency is a rare but highly thrombogenic inherited thrombophilia. Its association with adverse pregnancy outcomes (APO) is undefined. There is limited guidance on managing AT deficiency in pregnancy. Some significant issues remain controversial, including risk assessment for prophylactic anticoagulation, anticoagulant therapy, and monitoring. Our goal was to examine if the antepartum management of patients with AT deficiency affected their pregnancy outcomes. MATERIALS AND METHODS: This retrospective, single-center observational study included pregnant women with inherited AT deficiency in Peking Union Medical College Hospital between 2013 and 2024. RESULTS: Seventeen pregnancies in 6 women with AT deficiency were identified. A total of 7 pregnancies received adjusted-dose low-molecular-weight heparin (LMWH) and were monitored by anti-Xa level, AT activity, and D-dimer. There were 5 live births (all received LMWH), 7 second-trimester abortions (1 received LMWH), and 5 early pregnancy losses (1 received LMWH). There were 5 abruptio placentae events (3 received LMWH) and 7 thrombotic events (2 received LMWH). CONCLUSIONS: AT deficiency is at least an important partial factor contributing to APO. It is suggested to make a full assessment of AT patients both for venous thrombus embolism and APO risk. We observed a high prevalence of heparin resistance and a positive correlation between adequate anticoagulation and pregnancy outcome based on tight monitoring with anti-Xa level and timely adjustment of the LMWH dosage.

4.
EMBO Rep ; 22(4): e51298, 2021 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-33594776

RESUMO

Notch signaling and epigenetic factors are known to play critical roles in regulating tissue homeostasis in most multicellular organisms, but how Notch signaling coordinates with epigenetic modulators to control differentiation remains poorly understood. Here, we identify heterochromatin protein 1c (HP1c) as an essential epigenetic regulator of gut homeostasis in Drosophila. Specifically, we observe that HP1c loss-of-function phenotypes resemble those observed after Notch signaling perturbation and that HP1c interacts genetically with components of the Notch pathway. HP1c represses the transcription of Notch target genes by directly interacting with Suppressor of Hairless (Su(H)), the key transcription factor of Notch signaling. Moreover, phenotypes caused by depletion of HP1c in Drosophila can be rescued by expressing human HP1γ, suggesting that HP1γ functions similar to HP1c in Drosophila. Taken together, our findings reveal an essential role of HP1c in normal development and gut homeostasis by suppressing Notch signaling.


Assuntos
Proteínas de Drosophila , Animais , Proteínas Cromossômicas não Histona/genética , Drosophila/genética , Proteínas de Drosophila/genética , Heterocromatina , Homeostase , Humanos , Receptores Notch/genética
5.
J Org Chem ; 88(7): 4234-4243, 2023 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-36989519

RESUMO

Herein, we performed the reactions of M3N@Ih-C80 (M = Sc and Lu) with the methanol (CH3OH) solution of TBAOH (note that both CH3O- and OH- are nucleophiles) in benzonitrile (PhCN) and dimethylformamide, respectively. It is found that OH- ions rather than CH3O- ions selectively attacked the fullerene cage to form the M3N@C80--O- intermediate. Although the fullerene cage is initially attacked by OH- in both PhCN and DMF solvents, the products are quite different. In PhCN, two isomeric Sc3N@Ih-C80 fullerooxazoline heterocyclic products (1 and 2) were synthesized. Whereas, in DMF, an epoxide of Lu3N@Ih-C80 (3) was obtained. The preference for fullerooxazoline formation over that of fullerene epoxy in PhCN is well explained by density functional theory calculations. Plausible reaction mechanisms for the formation of metallofullerene oxazoline and epoxide were proposed based on the experimental and theoretical results.

6.
Environ Sci Technol ; 57(2): 1167-1176, 2023 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-36599128

RESUMO

Microplastics are readily accumulated in coastal sediments, where active sulfur (S) cycling takes place. However, the effects of microplastics on S cycling in coastal sediments and their underlying mechanisms remain poorly understood. In this study, the transformation patterns of different S species in mangrove sediments amended with different microplastics and their associated microbial communities were investigated using stable isotopic analysis and metagenomic sequencing. Biodegradable poly(lactic acid) (PLA) microplastics treatment increased sulfate (SO42-) reduction to yield more acid-volatile S and elementary S, which were subsequently transformed to chromium-reducible S (CRS). The S isotope fractionation between SO42- and CRS in PLA treatment increased by 9.1‰ from days 0 to 20, which was greater than 6.8‰ in the control. In contrast, recalcitrant petroleum-based poly(ethylene terephthalate) (PET) and polyvinyl chloride (PVC) microplastics had less impact on the sulfate reduction, resulting in 7.6 and 7.7‰ of S isotope fractionation between SO42- and CRS from days 0 to 20, respectively. The pronounced S isotope fractionation in PLA treatment was associated with increased relative abundance of Desulfovibrio-related sulfate-reducing bacteria, which contributed a large proportion of the microbial genes responsible for dissimilatory sulfate reduction. Overall, these findings provide insights into the potential impacts of microplastics exposure on the biogeochemical S cycle in coastal sediments.


Assuntos
Microplásticos , Plásticos , Isótopos de Enxofre/análise , Enxofre , Isótopos/análise , Poliésteres , Sulfatos/análise , Sedimentos Geológicos/análise
7.
Endocr Pract ; 29(5): 368-378, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36804969

RESUMO

OBJECTIVE: Wearable activity monitors are promising tools for improving metabolic outcomes in patients with type 2 diabetes mellitus (T2DM); however, no uniform conclusive evidence is available. This study aimed to evaluate the effects of the intervention using wearable activity monitors on blood glucose, blood pressure, blood lipid, weight, waist circumference, and body mass index (BMI) in individuals with T2DM. METHODS: Two independent reviewers searched 4 online databases (PubMed, Cochrane Library, Web of Science, and Embase) to identify relevant studies published from January 2000 to October 2022. The primary outcome indicator was hemoglobin A1c (HbA1c), and the secondary outcome indicators included physical activity (steps per day), fasting blood glucose, triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, total cholesterol, systolic blood pressure, diastolic blood pressure, BMI, waist circumference, and weight. RESULTS: A total of 25 studies were included. The HbA1c level (standardized mean difference [SMD], -0.14; 95% confidence interval [CI], -0.27 to -0.02; P = .02; I2 = 48%), BMI (SMD, -0.16; 95% CI, -0.26 to -0.05; P = .002; I2 = 0), waist circumference (SMD, -0.21; 95% CI, -0.34 to -0.09; P < .001; I2 = 0), and steps/day (SMD, 0.55; 95% CI, 0.36-0.94; P < .001; I2 = 77%) significantly improved. CONCLUSION: Wearable activity monitor-based interventions could facilitate the improvement of the HbA1c level, BMI, and waist circumference and increase in physical activity in individuals with T2DM. Wearable technology appeared to be an effective tool for the self-management of T2DM; however, there is insufficient evidence about its long-term effect.


Assuntos
Diabetes Mellitus Tipo 2 , Dispositivos Eletrônicos Vestíveis , Humanos , Hemoglobinas Glicadas , Glicemia/análise , HDL-Colesterol
8.
Biochem Genet ; 61(6): 2672-2690, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37222961

RESUMO

Gastric cancer (GC) is a common malignant tumor, posing a great threat to human's health and life. Previous studies have suggested aberrant expression of long non-coding RNAs (lncRNAs) in GC. This study elucidated the effects of lncRNA ACTA2-AS1 on the biological characteristics of GC. Gene expression in stomach adenocarcinoma (STAD) samples compared with normal tissues and the correlation between gene expression and prognosis of STAD patients were analyzed using bioinformatic tools. Gene expression at protein and mRNA levels in GC and normal cells was tested by western blotting and RT-qPCR. The subcellular localization of ACTA2-AS1 in AGS and HGC27 cells was identified by nuclear-cytoplasmic fractionation and FISH assay. EdU, CCK-8, flow cytometry analysis, TUNEL staining assays were conducted to evaluate the role of ACTA2-AS1 and ESRRB on GC cellular behaviors. The binding relationship among ACTA2-AS1, miR-6720-5p and ESRRB was verified by RNA pulldown, luciferase reporter assay and RIP assay. LncRNA ACTA2-AS1 was underexpressed in GC tissues and cell lines. ACTA2-AS1 elevation suppressed GC cell proliferation and induced apoptosis. Mechanistically, ACTA2-AS1 directly bound to miR-6720-5p and subsequently promoted the expression of target gene ESRRB in GC cells. Furthermore, ESRRB knockdown reversed the influence of ACTA2-AS1 overexpression on GC proliferation and apoptosis. ACTA2-AS1 plays an antioncogenic role in GC via binding with miR-6720-5p to regulate ESRRB expression.


Assuntos
MicroRNAs , RNA Longo não Codificante , Neoplasias Gástricas , Humanos , MicroRNAs/genética , RNA Longo não Codificante/genética , Neoplasias Gástricas/patologia , Linhagem Celular Tumoral , Proliferação de Células/genética , Apoptose/genética , Regulação Neoplásica da Expressão Gênica , Movimento Celular/genética , Receptores de Estrogênio/genética , Actinas/genética
9.
Arch Gynecol Obstet ; 307(1): 263-274, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35474494

RESUMO

PURPOSE: To analyze the clinical characteristics of abdominal pregnancy, and to explore the diagnosis and prognosis of different treatment methods. METHODS: The cases of patients with abdominal pregnancy admitted to Peking Union Medical College Hospital between January 1, 1989 and January 1, 2021, were analyzed retrospectively. RESULTS: The median age of 17 patients was 34 years (22-42 years); the median gestational duration was 57 days (from 41 days to 32 weeks). Among all 17 patients, 15 (88.24%) presented with abdominal pain. The implantation sites of the gestational sac included the bladder peritoneal reflection, anterior wall of the rectum, omentum, serous membrane of the uterus, and inside or on the surface of uterosacral ligament. In all, only 29.41% cases (5/17) were diagnosed before surgery. All 17 patients were treated via surgery. Further, 58.82% (10/17) patients recovered without complications, 29.41% (5/17) developed fever, 5.88% (1/17) underwent reoperation because of intra-abdominal bleeding, and 5.88% (1/17) developed double lower limb venous thrombosis. All 17 patients survived. CONCLUSION: The preoperative diagnosis rate of abdominal pregnancy is low. Planting sites in the pelvic peritoneum and pelvic organs are more common than the others. Laparoscopic surgery in the first trimester of pregnancy can achieve better therapeutic effects. However, the blood supply of the placenta should be fully evaluated before surgery. When it is expected that attempts to remove the placenta will cause fatal bleeding, the placenta can be left in place, but long-term close follow-up should be paid attention to.


Assuntos
Gravidez Abdominal , Gravidez , Feminino , Humanos , Adulto , Gravidez Abdominal/diagnóstico , Gravidez Abdominal/cirurgia , Estudos Retrospectivos , Placenta , Primeiro Trimestre da Gravidez , Útero
10.
Molecules ; 28(3)2023 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-36770610

RESUMO

Panax ginseng is widely used in Asian countries and its active constituents-ginsenosides-need to be systematically studied. However, only a small part of ginsenosides have been characterized in the roots and rhizomes of panax ginseng (RRPG) up to date, mainly because of a lack of the fragmentation ions of many more ginsenosides. In order to comprehensively identify ginsenosides in RRPG, molecular features of ginsenosides orienting precursor ions selection and targeted tandem mass spectrometry (MS/MS) analysis strategy were proposed in our study, in which the precursor ions were selected according to the molecular features of ginsenosides irrespective of their peak abundances, and targeted MS/MS analysis was then performed to obtain their fragmentation ions for substance characterization. Using this strategy, a total of 620 ginsenosides were successfully characterized in RRPG, including 309 protopanaxadiol-type ginsenosides, 258 protopanaxatriol-type ginsenosides and 53 oleanane-type ginsenosides. It is worth noting that, except for the known aglycones mass-to-charge ratio (m/z) 459, 475 and 455, twelve other aglycones, including m/z 509, 507, 493, 491, 489, 487, 477, 473, 461, 457, 443 and 441, were first reported in our experiment and they were probably the derivatizations of the protopanaxatriol and protopanaxadiol. Our study will not only help people to improve the cognition of ginsenosides in RRPG, but will also play a guiding and reference role for the isolation and characterization of potentially new ginsenosides from RRPG.


Assuntos
Ginsenosídeos , Panax , Humanos , Espectrometria de Massas em Tandem/métodos , Rizoma/química , Ginsenosídeos/química , Panax/química , Cromatografia Líquida de Alta Pressão/métodos , Raízes de Plantas/química , Íons/análise
11.
Molecules ; 28(5)2023 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-36903317

RESUMO

Panax ginseng was a traditional Chinese medicine with various pharmacological activities and one of its important activities was hypoglycemic activity; therefore, panax ginseng has been used in China as an adjuvant in the treatment of diabetes mellitus. In vivo and in vitro tests have revealed that ginsenosides, which are derived from the roots and rhizomes of panax ginseng have anti-diabetic effects and produce different hypoglycemic mechanisms by acting on some specific molecular targets, such as SGLT1, GLP-1, GLUTs, AMPK, and FOXO1. α-Glucosidase is another important hypoglycemic molecular target, and its inhibitors can inhibit the activity of α-Glucosidase so as to delay the absorption of dietary carbohydrates and finally reduce postprandial blood sugar. However, whether ginsenosides have the hypoglycemic mechanism of inhibiting α-Glucosidase activity, and which ginsenosides exactly attribute to the inhibitory effect as well as the inhibition degree are not clear, which needs to be addressed and systematically studied. To solve this problem, affinity ultrafiltration screening coupled with UPLC-ESI-Orbitrap-MS technology was used to systematically select α-Glucosidase inhibitors from panax ginseng. The ligands were selected through our established effective data process workflow based on systematically analyzing all compounds in the sample and control specimens. As a result, a total of 24 α-Glucosidase inhibitors were selected from panax ginseng, and it was the first time that ginsenosides were systematically studied for the inhibition of α-Glucosidase. Meanwhile, our study revealed that inhibiting α-Glucosidase activity probably was another important mechanism for ginsenosides treating diabetes mellitus. In addition, our established data process workflow can be used to select the active ligands from other natural products using affinity ultrafiltration screening.


Assuntos
Ginsenosídeos , Panax , Rizoma/química , Ginsenosídeos/farmacologia , Inibidores de Glicosídeo Hidrolases , Cromatografia Líquida de Alta Pressão/métodos , Ultrafiltração , alfa-Glucosidases , Raízes de Plantas/química
12.
Environ Sci Technol ; 56(3): 1951-1962, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-35015551

RESUMO

Although chlorinated organophosphate esters (Cl-OPEs) have been reported to be ubiquitously distributed in various anoxic environments, little information is available on their fate under anoxic conditions. In this study, we report two Dehalococcoides-containing enrichment cultures that transformed 3.88 ± 0.22 µmol tris(2-chloroethyl) phosphate (TCEP) and 2.61 ± 0.02 µmol tris(1-chloro-2-propyl) phosphate (TCPP) within 10 days. Based on the identification of the transformed products and deuteration experiments, we inferred that TCEP may be transformed to generate bis(2-chloroethyl) phosphate and ethene via one-electron transfer (radical mechanism), followed by C-O bond cleavage. Ethene was subsequently reduced to ethane. Similarly, TCPP was transformed to form bis(1-chloro-2-propyl) phosphate and propene. 16S rRNA gene amplicon sequencing and quantitative polymerase chain reaction analysis revealed that Dehalococcoides was the predominant contributor to the transformation of TCEP and TCPP. Two draft genomes of Dehalococcoides assembled from the metagenomes of the TCEP- and TCPP-transforming enrichment cultures contained 14 and 15 putative reductive dehalogenase (rdh) genes, respectively. Most of these rdh genes were actively transcribed, suggesting that they might contribute to the transformation of TCEP and TCPP. Taken together, this study provides insights into the role of Dehalococcoides during the transformation of representative Cl-OPEs.


Assuntos
Retardadores de Chama , Dehalococcoides , Ésteres , Retardadores de Chama/análise , Organofosfatos/análise , Fosfatos , RNA Ribossômico 16S/genética
13.
Environ Sci Technol ; 56(1): 119-130, 2022 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-34882389

RESUMO

N-containing organic compounds (NOCs) in humic-like substances (HULIS) emitted from biomass burning (BB) and coal combustion (CC) were characterized by ultrahigh-resolution mass spectrometry in the positive electrospray ionization mode. Our results indicate that NOCs include CHON+ and CHN+ groups, which are detected as a substantial fraction in both BB- and CC-derived HULIS, and suggest that not only BB but also CC is the potential important source of NOCs in the atmosphere. The CHON+ compounds mainly consist of reduced nitrogen compounds with other oxygenated functional groups, and straw- and coal-smoke HULIS exhibit a lower degree of oxidation than pine-smoke HULIS. In addition, the NOCs with higher N atoms (N2 and/or N3) generally bear higher modified aromaticity index (AImod) values and are mainly contained in BB HULIS, especially in straw-smoke HULIS, whereas the NOCs with a lower N atom (N1) always have relatively lower AImod values and are the dominant NOCs in CC HULIS. These findings imply that the primary emission from CC may be a significant source of N1 compounds, whereas high N number (e.g., N2-3) compounds could be associated with burning of biomass materials. Further study is warranted to distinguish the NOCs from more sources.


Assuntos
Poluentes Atmosféricos , Carvão Mineral , Aerossóis/análise , Poluentes Atmosféricos/análise , Biomassa , Monitoramento Ambiental , Substâncias Húmicas/análise , Nitrogênio/análise , Compostos de Nitrogênio/análise , Material Particulado/análise
14.
Environ Sci Technol ; 56(14): 10239-10248, 2022 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-35790344

RESUMO

Extremely high levels of decabromodiphenyl ether (BDE-209) are frequently found in the serum of occupationally exposed groups, such as e-waste dismantlers and firefighters. However, the metabolism of BDE-209 in the human body is not adequately studied. In this study, 24 serum samples were collected from workers at a typical e-waste recycling workshop in Taizhou, Eastern China, and the occurrence and fate of these higher brominated diphenyl ethers (PBDEs) were investigated. The median concentration of the total PBDEs in the serum was 199 ng/g lipid weight (lw), ranging from 125 to 622 ng/g lw. Higher brominated octa- to deca-BDEs accounted for more than 80% of the total PBDEs. Three ortho-hydroxylated metabolites of PBDEs─6-OH-BDE196, 6-OH-BDE199, and 6'-OH-BDE206─were widely detected with a total concentration (median) of 92.7 ng/g lw. The concentrations of the three OH-PBDEs were significantly higher than their octa- and nona-PBDE homologues, even exceeding those of the total PBDEs in several samples, indicating that the formation of OH-PBDEs was a major metabolic pathway of the higher brominated PBDEs in occupationally exposed workers. An almost linear correlation between 6-OH-BDE196 and 6-OH-BDE199 (R = 0.971, P < 0.001) indicates that they might undergo a similar biotransformation pathway in the human body or may be derived from the same precursor. In addition, the occurrence of a series of penta- to hepta- ortho-substituted OH-PBDEs was preliminarily identified according to their unique "predioxin" mass spectral profiles by GC-ECNI-MS. Taken together, the tentative metabolic pathway for BDE-209 in e-waste dismantlers was proposed. The oxidative metabolism of BDE-209 was mainly observed at the ortho positions to form 6'-OH-BDE-206, which later underwent a consecutive loss of bromine atoms at the meta or para positions to generate other ortho-OH-PBDEs. Further studies are urgently needed to identify the chemical structures of these ortho-OH-PBDE metabolites, and perhaps more importantly to clarify the potentially toxic effects, along with their underlying molecular mechanisms.


Assuntos
Resíduo Eletrônico , Éteres Difenil Halogenados , Biotransformação , Resíduo Eletrônico/análise , Monitoramento Ambiental , Éteres Difenil Halogenados/análise , Humanos
15.
Environ Res ; 212(Pt A): 113212, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35367230

RESUMO

Nine amine species in atmospheric particles during haze and low-pollution days with low and high relative humidity (RH) were analyzed in urban Guangzhou, China. The mean concentrations of total measured amines (Æ©amines) in fine particles were 208 ± 127, 63.7 ± 21.3, and 120 ± 20.1 ng m-3 during haze, low pollution-low RH (LP-LRH), and low pollution-high RH (LP-HRH) episodes, respectively. The dominant amine species were methylamine (MA), dimethylamine (DMA), diethylamine (DEA) and dibutylamine (DBA), which in total accounted for 82-91% of the Æ©amines during different pollution episodes. The contributions of Æ©amines-C to water-soluble organic carbon (WSOC) and Æ©amines-N to water-soluble organic nitrogen (WSON) were 1.52% and 2.49% during haze, 1.24% and 1.96% during LP-LRH, and 2.00 and 2.98% during LP-HRH days, respectively. The mass proportion of Æ©amines in fine particles was higher during LP-HRH periods (0.19%) than during haze and LP-LRH periods (0.16%). The mass proportion of DBA in Æ©amines increased from 7% during haze and LP-LRH episodes to 25% during LP-HRH episodes. Compared with other amines, DBA showed a stronger linear relationship with RH (r = 0.867, p < 0.01), which demonstrates its high sensitivity to high RH conditions. Meteorological parameters (including RH, the mixed layer depth, wind speed and temperature), the oxidizing capacity (ozone concentration), and gaseous pollutants (NOx and SO2) correlated with amines under different pollution conditions. Under high RH, acid-base reactions were the dominant pathway for the gas-to-particle distribution of amines in urban areas, while direct dissolution dominated in the background site. To our knowledge, this study is the first attempt to conduct in situ measurements of particulate amines during different pollution conditions in China, and further research is needed to in-depth understanding of the influence of amines on haze formation.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Aminas , Aerossóis/análise , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Aminas/análise , China , Poeira , Monitoramento Ambiental , Umidade , Oxirredução , Material Particulado/análise , Rios , Água
16.
Ecotoxicol Environ Saf ; 241: 113730, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35691194

RESUMO

Severe pollution of polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and their brominated analogues (PBDD/Fs) was frequently reported for the waters located near unregulated e-waste recycling areas. However, the migrations of these high-level dioxins via waterways and their potential threats to the lower reaches were seldom investigated. In this study, we analyzed PCDD/Fs and PBDD/Fs in 27 surficial sediments collected from the Lian River encompassing the Guiyu, China e-waste recycling zone, and investigated their distributions, sources, migration behaviors and risks. Both PCDD/Fs and PBDD/Fs in these sediments exhibited a spatial trend of Guiyu > Guiyu downriver > Guiyu upriver, illustrating that the Guiyu e-waste recycling activities were the uppermost dioxin contributors in this watershed. Sediments from different Guiyu villages demonstrated big gaps in PCDD/F concentrations and congener compositions, and the reason was attributed to the diverse e-waste recycling activities practiced in these villages. Sediments near the e-waste open-burning areas demonstrated extremely high PCDD/F concentrations and unique PCDD/F profiles featured by low-chlorinated PCDFs (tetra- to hexa-), which is quite different from the OCDD-dominant PCDD/F profile found in most of the Lian River sediments. The geographical distributions of PCDD/F concentrations and profiles illustrate that the substantial amount of PCDD/Fs in Guiyu sediments were mainly retained in local and vicinal water bodies. The principal component analysis (PCA) results further confirm that the high-level PCDD/Fs in Guiyu sediments exhibited quite limited translocations downstream and therefore exerted little influences on the lower reaches. Pentachlorophenol use in history, ceramic industry and vehicle exhaust were diagnosed as the major PCDD/F sources for most sediments of the Lian River. Total toxicity equivalent quantities (TEQs) of 70% of the Lian River sediments surpassed the high-risk limit specified for mammalian life by the U.S.EPA (25 pg TEQ g-1), and most of these sediments were from Guiyu and its near downstream, which merit continuous attention and necessary remediation measures.


Assuntos
Benzofuranos , Dioxinas , Resíduo Eletrônico , Dibenzodioxinas Policloradas , Benzofuranos/análise , China , Dibenzofuranos/análise , Dibenzofuranos Policlorados/análise , Dioxinas/análise , Resíduo Eletrônico/análise , Monitoramento Ambiental , Dibenzodioxinas Policloradas/análise
17.
Chemistry ; 27(40): 10405-10412, 2021 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-33938057

RESUMO

Inspired by the spongy bone structures, three-dimensional (3D) sponge-like carbons with meso-microporous structures are synthesized through one-step electro-reduction of CO2 in molten carbonate Li2 CO3 -Na2 CO3 -K2 CO3 at 580 °C. SPC4-0.5 (spongy porous carbon obtained by electrolysis of CO2 at 4 A for 0.5 h) is synthesized with the current efficiency of 96.9 %. SPC4-0.5 possesses large electrolyte ion accessible surface area, excellent wettability and electronical conductivity, ensuring the fast and effective mass and charge transfer, which make it an advcanced supercapacitor electrode material. SPC4-0.5 exhibits a specific capacitance as high as 373.7 F g-1 at 0.5 A g-1 , excellent cycling stability (retaining 95.9 % of the initial capacitance after 10000 cycles at 10 A g-1 ), as well as high energy density. The applications of SPC4-0.5 in quasi-solid-state symmetric supercapacitor and all-solid-state flexible devices for energy storage and wearable piezoelectric sensor are investigated. Both devices show considerable capacitive performances. This work not only presents a controllable and facile synthetic route for the porous carbons but also provides a promising way for effective carbon reduction and green energy production.


Assuntos
Dióxido de Carbono , Carbono , Capacitância Elétrica , Eletrodos , Porosidade
18.
Analyst ; 146(22): 6960-6969, 2021 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-34657942

RESUMO

Digital PCR has shown great potential for quantitative nucleic acid testing (NAT), but most existing platforms are dependent on large auxiliary equipment (e.g., vacuum pump, amplification instrument, fluorescence microscope) to achieve target dispersion, amplification, signal capture and result analysis. Such complex, expensive and bulky NAT platforms have limited their applications in resource-limited areas, especially for point-of-care testing (POCT). In this work, we designed a digital isothermal NAT platform based on a pump-free open droplet array microfluidic chip. A pump-free microfluidic chip was developed based on an open microdroplet array in the form of thousands of independent microdroplets for spontaneous sample dispersion, without the need for external power. Combined with a handheld fluorescent signal reader based on a smartphone, this digital NAT platform can accurately quantify as low as 1 copy per µL of λDNA. Therefore, our integrated NAT platform, as a potable, robust and low-cost tool for highly accurate NA quantitative analysis, holds great potential for POCT applications.


Assuntos
Técnicas Analíticas Microfluídicas , Ácidos Nucleicos , Dispositivos Lab-On-A-Chip , Microfluídica , Técnicas de Amplificação de Ácido Nucleico
19.
Analyst ; 146(9): 2871-2877, 2021 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-33899835

RESUMO

A highly sensitive ELISA is critical for early diagnosis and biomarker discovery of various diseases. Although various ELISA technologies have been developed with high sensitivity, they are limited by poor repeatability, high cost, the dependence on complex equipment and/or a prolonged reaction time. To this end, we developed a fast and ultrasensitive ELISA (termed RELISA) based on rolling circle amplification (RCA) and enzymatic signal amplification. The RELISA is established on the traditional ELISA, with only one more RCA step that can be accomplished within 10 minutes. The prolonged single strand DNA (ssDNA) from RCA is able to enrich abundant horseradish peroxidase conjugate (HRP) modified detection probes. Consequently, the intensive HRP is able to catalyze TMB-H2O2 to produce significantly enhanced colorimetric signals. With CEACAM-7 as a model biomarker, the RELISA achieves the limit of detection as low as 2.82 pg mL-1, which is ∼50 times higher than that of the traditional ELISA. Therefore, we envision that the developed RELISA would be a powerful tool for the early diagnosis of various major diseases.


Assuntos
Técnicas Biossensoriais , Técnicas de Amplificação de Ácido Nucleico , Colorimetria , Ensaio de Imunoadsorção Enzimática , Peroxidase do Rábano Silvestre , Peróxido de Hidrogênio
20.
Proc Natl Acad Sci U S A ; 115(18): 4719-4724, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29666231

RESUMO

CRISPR/Cas9-based transcriptional activation (CRISPRa) has recently emerged as a powerful and scalable technique for systematic overexpression genetic analysis in Drosophila melanogaster We present flySAM, a potent tool for in vivo CRISPRa, which offers major improvements over existing strategies in terms of effectiveness, scalability, and ease of use. flySAM outperforms existing in vivo CRISPRa strategies and approximates phenotypes obtained using traditional Gal4-UAS overexpression. Moreover, because flySAM typically requires only a single sgRNA, it dramatically improves scalability. We use flySAM to demonstrate multiplexed CRISPRa, which has not been previously shown in vivo. In addition, we have simplified the experimental use of flySAM by creating a single vector encoding both the UAS:Cas9-activator and the sgRNA, allowing for inducible CRISPRa in a single genetic cross. flySAM will replace previous CRISPRa strategies as the basis of our growing genome-wide transgenic overexpression resource, TRiP-OE.


Assuntos
Animais Geneticamente Modificados , Sistemas CRISPR-Cas , Proteínas de Drosophila , Regulação da Expressão Gênica/genética , Fatores de Transcrição , Animais , Animais Geneticamente Modificados/genética , Animais Geneticamente Modificados/metabolismo , Proteínas de Drosophila/biossíntese , Proteínas de Drosophila/genética , Drosophila melanogaster , Fatores de Transcrição/biossíntese , Fatores de Transcrição/genética
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