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1.
Nano Lett ; 2020 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-33200603

RESUMO

Graphene on SiO2 enables fabrication of Si-technology-compatible devices, but a transfer of these devices from other substrates and direct growth have severe limitations due to a relatively small grain size or device-contamination. Here, we show an efficient, transfer-free way to integrate centimeter-scale, single-crystal graphene, of a quality suitable for electronic devices, on an insulating SiO2 film. Starting with single-crystal graphene grown epitaxially on Ru(0001), a SiO2 film is grown under the graphene by stepwise intercalation of silicon and oxygen. Thin (∼1 nm) crystalline or thicker (∼2 nm) amorphous SiO2 has been produced. The insulating nature of the thick amorphous SiO2 is verified by transport measurements. The device-quality of the corresponding graphene was confirmed by the observation of Shubnikov-de Haas oscillations, an integer quantum Hall effect, and a weak antilocalization effect within in situ fabricated Hall bar devices. This work provides a reliable platform for applications of large-scale, high-quality graphene in electronics.

2.
J Hazard Mater ; : 124285, 2020 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-33189463

RESUMO

There is a great need for efficiently treating papermaking black liquor because it can seriously pollute both soil and water ecosystems. In this study, the Plackett-Burman (PB) experimental design combined with response surface methodology (RSM) was used for improving the biodegradation efficiency of lignin by a new isolated thermophilic and alkali-tolerant strain Serratia sp. AXJ-M, and the results showed that a biodegradation efficiency of 70.5% was achieved under optimal culture conditions. The bacterium with ligninolytic activities significantly decreased target the parameters (color 80%, lignin 60%, phenol 95%, BOD 80% and COD 80%). The control and treated samples were analyzed by gas chromatography-mass spectrometer (GC-MS), which showed that the concentrations of a majority of low-molecular-weight compounds were decreased after biological treatment. Furthermore, toxicological, genotoxicity and phytotoxicity studies have supported the detoxification by the bacterium of black liquor. Finally, the genome sequence of the thermophilic, alkali-tolerant and lignin-degrading bacterium AXJ-M was completed, and the genetic basis of the thermophilic and alkali-resistant properties of AXJ-M was preliminarily revealed. The dyp-type peroxidase was first reported to have the potential to catalyze lignin degradation structurally. These findings suggest that Serratia sp. AXJ-M may be potentially useful for bioremediation applications for papermaking black liquor.

3.
Environ Sci Technol ; 2020 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-33190472

RESUMO

Arctic and Antarctic marine ecosystems, which are important components of global biodiversity, have been severely threatened by environmental pollutants in recent decades. In this study, polybrominated diphenyl ethers (PBDEs) and their hydroxylated and methoxylated analogues (OH-PBDEs and MeO-PBDEs) were analyzed in seawater, sediment, and marine organisms (algae, invertebrates, and fishes) collected surrounding the Arctic Yellow River Station (n = 83) and the Antarctic Great Wall Station (n = 72). PBDEs and the analogues were detectable in all polar marine matrices, except MeO-PBDEs in seawater. The concentrations of ∑PBDEs, ∑MeO-PBDEs, and ∑OH-PBDEs in the marine organisms were in the range of 0.33-16 ng/g lipid weight (lw), n.d.-2.6 ng/g lw, and 0.12-2.3 ng/g lw in the Arctic and 0.06-31 ng/g lw, n.d.-5.8 ng/g lw, and 0.17-35 ng/g lw in Antarctica, respectively. Biota-sediment bioaccumulation factor (BSAF, g TOC/g lipid) values of MeO-PBDEs (0.002-0.14) and OH-PBDEs (0.004-0.18) were lower than the BSAF values of PBDEs (0.85-12). Trophic magnification was found for ∑MeO-PBDEs, whereas trophic dilution was observed for ∑OH-PBDEs in both regions. This is one of very few investigations on trophic transfer of PBDE metabolites in the Antarctic and Arctic regions and will further strengthen concerns about the ecological risk of PBDE metabolites in remote areas.

4.
Chemosphere ; : 128859, 2020 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-33176912

RESUMO

Passive air samples were deployed in Ny-Ålesund and London Island (Svalbard, High Arctic) annually for seven years (2011-2018) to investigate concentrations, temporal trends and potential sources of selected persistent organic pollutants (POPs). Nine polychlorinated biphenyls and twelve organochlorine pesticides were detected in all samples, with 3,3'-dichlorobiphenyl (PCB-11) being the prevalent congener. Concentrations of most compounds were declining. The ratio of the α- and γ-isomer of hexachlorocyclohexane (HCH) in Arctic air was comparable with that in technical HCH mixtures, but higher than that in the atmosphere of other countries, thereby indicating the impact of historical use as well as the possible photoisomerization of the γ- into the α-isomer. The parent dichlorodiphenyltrichloroethane (DDT) was always less abundant than its degradation products dichlorodiphenylethylene (DDE), indicative of the impact of aged DDT sources in the Arctic atmosphere. However, o,p'-/p,p'-DDT ratios suggest only a minor contribution of dicofol-type DDT. A slightly declining temporal trend of the trans-chlordane/cis-chlordane ratio indicated the impact of secondary sources. The atmospheric distribution of the investigated POPs in the Arctic was mainly attributed to long-range atmospheric transport, whereas the influence of human activities from the scientific research stations was minor.

5.
Small ; : e2004727, 2020 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-33136339

RESUMO

Ethanol is preferred to be oxidized into CO2 for the construction of a high-performance direct ethanol fuel cell since this complete ethanol oxidation reaction (EOR) transfers 12 electrons. However, this EOR is sluggish and has the low activity as well as poor selectivity. To promote such a favorable EOR, more exactly the cleavage selectivity of CC bonds in ethanol, phosphorus-doped silver-core-and-Pd-shell catalysts (denoted as Ag@PdP) are designed and synthesized. In the alkaline media, a Ag@Pd2 P0.2 catalyst is superior toward EOR into CO2 . It exhibits seven times higher mass activity and six times higher selectivity than the benchmark Pd/C catalyst. As confirmed by means of density functional theory calculation and in situ Fourier-transform infrared spectroscopy, such high performance stems from an increased adsorption energy of OH radicals on the Pd active sites. Meanwhile, the tensile strain effect of a core-shell structure of this Ag@Pd2 P0.2 catalyst favors the formation of adsorbed CH3 CO intermediate, the key species for the enhanced C-C cleavage into CO2 , instead of acetate. The proposed way to design and synthesize such high-performance EOR catalysts will explore the practical applications of direct alkaline ethanol fuel cells.

6.
Ecotoxicol Environ Saf ; 206: 111399, 2020 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-33022444

RESUMO

Organophosphate esters (OPEs) in atmospheric fine particles (PM2.5) were comprehensively investigated in the Beijing-Tianjin-Hebei (BTH) region from April 2016 to March 2017. The concentrations of Σ8OPEs in all the five sampling sites ranged from 90 to 8291 pg/m3 (mean 1148 ± 1239 pg/m3; median 756 pg/m3). The highest level (median 1067 pg/m3) was found at one of the urban sites in Beijing, followed by Tianjin (746 pg/m3) and Shijiazhuang (724 pg/m3). Tris(2-chloroethyl) phosphate (TCEP) and tri[(2R)-1-chloro-2-propyl] phosphate (TCPP) were the dominant compounds across the five sampling locations. Generally, the concentrations of chlorinated OPEs were relatively higher in summer than in winter (p < 0.05), but no significant seasonal difference was discovered for non-chlorinated individual OPEs. The concentrations of tri-n-butyl phosphate (TBP), TCEP, TCPP and triphenyl phosphate (TPP) were positively correlated with the meteorological parameters (i.e. temperature and relative humidity) (p < 0.05), indicating an evident influence of meteorological condition on OPE distribution. We observed a negative correlation (p < 0.05) between octanol-air partition coefficients (logKoa) and the ratio of PM2.5-bound OPE concentrations to total suspended particulates-bound OPE concentrations, suggesting that physicochemical properties affect the particle-size distribution of OPEs. Furthermore, the median value of cancer hazard quotients (HQs) of TCEP was higher than TBP and tris(2-ethylhexyl) phosphate (TEHP). The health risk assessment showed that HQ values for children were ~1.6 times higher than those for adults. Relatively higher health risk induced by PM2.5-bound OPEs via inhalation was found during severe hazy days than in clear days.

7.
Nanoscale Horiz ; 2020 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-33089267

RESUMO

Two-dimensional (2D) transition metal carbides and nitrides known as MXenes have shown attractive functionalities such as high electronic conductivity, a wide range of optical properties, versatile transition metal and surface chemistry, and solution processability. Although extensively studied computationally, the magnetic properties of this large family of 2D materials await experimental exploration. 2D magnetic materials have recently attracted significant interest as model systems to understand low-dimensional magnetism and for potential spintronic applications. Here, we report on synthesis of Cr2TiC2Tx MXene and a detailed study of its magnetic as well as electronic properties. Using a combination of magnetometry, synchrotron X-ray linear dichroism, and field- and angular-dependent magnetoresistance measurements, we find clear evidence of a magnetic transition in Cr2TiC2Tx at approximately 30 K, which is not present in its bulk layered carbide counterpart (Cr2TiAlC2 MAX phase). This work presents the first experimental evidence of a magnetic transition in a MXene material and provides an exciting opportunity to explore magnetism in this large family of 2D materials.

8.
Cancer Med ; 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-33084161

RESUMO

This retrospective study aimed to investigate ethnic disparities in demographic, clinicopathologic, and biological behaviours of gastric cancer (GC) in a high GC incidence area of China. There were 5022 GC patients, including 3987 Han (79.4%) and 987 Hui (14.4%) patients from Northwest China. All patient data were retrieved from 2009 to 2017. Median survival was estimated using the Kaplan-Meier method and compared using the log-rank test. A Cox proportional hazards model was used to assess the impact of covariates. Similarly, low 5-year OS rates were observed in both the Hui and Han groups (23.8% and 24.2% respectively). Hui patients with stage T1 or N0 or with tumours <5 cm had 2.144-fold, 1.426-fold and 1.305-fold increased risks of poor prognosis compared with Han patients with these characteristics respectively (all p < 0.05). Further, Hui patients had 1.265-fold, 1.364-fold and 1.401-fold increased risks of poor prognosis compared with Han patients among those with high expression of Ki67, EGFR and VEGF respectively (all p < 0.05). There are ethnic disparities in the prognosis of GC patients in Northwest China. Understanding the effects of ethnicity on GC will guide reasonable evaluations of prognosis and future interventions to equalise access to high-quality care for GC patients of different ethnicities in China.

9.
Front Immunol ; 11: 1738, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33013827

RESUMO

Chemokine-induced chemotaxis of leukocytes is an important part of the innate immunity and has been shown to mediate inflammation in all groups of jawed vertebrates. For jawless vertebrates, hagfish leukocytes are known to show chemotaxis toward mammalian complement anaphylotoxin and Gram-negative bacteria lipopolysaccharide. However, whether chemokines mediate chemotaxis of leukocytes in jawless vertebrates has not been conclusively examined. Here, we show C-X-C motif chemokine ligand 8 (CXCL8, also named interleukin 8) of the Northeast Chinese lamprey (Lethenteron morii) (designated as LmCXCL8) induces chemotaxis in its leukocytes. We identified LmCXCL8 and found it possesses the characteristic N-terminal cysteine residues and GGR (Gly-Gly-Arg) motif. The Lmcxcl8 gene was found to be expressed in all examined tissues, and its expression was inducible in the lamprey challenged by an infectious bacterium, Pseudomonas aeruginosa. A recombinant LmCXCL8 protein elicited concentration-dependent chemotaxis in peripheral blood leukocytes isolated from the Northeast Chinese lamprey. Based on these results, we conclude that LmCXCL8 is a constitutive and inducible acute-phase cytokine that mediates immune defense and trace the chemotactic function of chemokine to basal vertebrates.

10.
Water Sci Technol ; 82(5): 877-886, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33031067

RESUMO

Water pollution from antibiotics has attracted a lot of attention for its serious threat to human health. In this study, a magnetic adsorbent (zinc ferrite/activated carbon (ZnFe2O4/AC) was synthesized via microwave method to effectively remove gemifioxacin mesylate (GEM) and moxifloxacin hydrochloride (MOX). Based on the porosity of AC and the magnetism of ZnFe2O4, the resulting ZnFe2O4/AC has high adsorption capacities and can be easily separated from the solid-liquid system via a magnetic field. The largest adsorption capacities for GEM and MOX can reach up to 433.4 mg g-1 and 388.8 mg g-1, respectively, higher than those of reported adsorbents such as MIL-101 and MOF-808. Fastest adsorptions of GEM and MOX were found at 5 min, and solution pH and coexisting salts do not have a significant influence on the adsorption process. The adsorption mechanism analysis indicates that electrostatic interaction and H-bond interaction contribute to the effective adsorption.


Assuntos
Carvão Vegetal , Poluentes Químicos da Água , Adsorção , Antibacterianos , Magnetismo
11.
Artigo em Chinês | MEDLINE | ID: mdl-33040507

RESUMO

Objective:To analyze the clinical characteristics of patients with Meniere's disease and vestibular migraine, improve the understanding of such diseases for accurate treatment. Method:Eighteen patients with MD and VM were reviewed and the clinical characteristics of the patients were evaluated. Result:There were 4 males and 14 females whose average age was 55.2 years old. The average onset age was 36.5 years meanwhile the headache occured 7.5 years earlier than the vertigo. The average time of vertigo attacks was 30 min-24 h; The mainly kind of headache was unilateral pulsatile headache with or without vertigo attacks; All patients showed the characteristics of photophobia or phonophobia, 7 of them showed visual aura and 9 of them experienced vertigo attacks with headache but without auditory symptoms; 11 patients experienced motion sickness and 10 patients had a related family history. Electrocochleogram abnormal was 11 ears; c-VEMP abnormal was 11 cases; Caloric test abnormal was 13 cases; Velocity step test abnormal was 4 cases. Conclusion:MD and VM shows recurrent vertigo, There are evidences of hearing loss and abnormal changes of electrocochleogram、c-VEMP and lateral semicircular canal function in MD; VM experienced migraine attacks with the characteristics of photophobia、phonophobia and visual aura; The patients can be diagnosed with overlap syndrome when they fulfill the diagnostic criteria of MD and VM at the same time and the two diseases should be treated at the same time.


Assuntos
Doença de Meniere , Transtornos de Enxaqueca , Tontura , Feminino , Cefaleia , Humanos , Masculino , Doença de Meniere/complicações , Doença de Meniere/diagnóstico , Pessoa de Meia-Idade , Transtornos de Enxaqueca/diagnóstico , Vertigem/diagnóstico
12.
Plant J ; 2020 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-33118252

RESUMO

For diploid organisms that are highly heterozygous, a phased haploid genome can greatly aid in functional genomic, population genetic and breeding studies. Based on the genome sequencing of 135 single sperm cells of the elite tea cultivar "Fudingdabai", we herein phased the genome of Camellia sinensis, one of the most popular beverage crops worldwide. High-resolution genetic and recombination maps of Fudingdabai were constructed, which revealed that crossover (CO) positions were frequently located in the 5' and 3' ends of annotated genes, while CO distributions across the genome were random. Low CO frequency in tea can be explained by strong CO interference, and CO simulation revealed the proportion of interference insensitive CO ranged from 5.2% to 11.7%. We furthermore developed a method to infer the relatedness between tea accessions and detected complex kinship and genetic signatures of 106 tea accessions. Among them, 59 accessions were closely related with Fudingdabai and 31 of them were first degree relatives. We additionally identified genes displaying allele specific expression (ASE) patterns between the two haplotypes of Fudingdabai and genes displaying significantly differential expression levels between Fudingdabai and other haplotypes. These results lay the foundation for further investigation of genetic and epigenetic factors underpinning the regulation of gene expression and provide insights into the evolution of tea plants as well as a valuable genetic resource for future breeding efforts.

13.
Adv Mater ; : e2002968, 2020 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-33118254

RESUMO

Ferroelectric materials usually undergo decay with particle size decreasing into the nanoscale. At the critical value, the crystal structure undergoes a transition from the ferroelectric to paraelectric phase and the ferroelectricity vanishes. It is a big issue to sufficiently maintain strong ferroelectricity at the nanoscale. Herein, it is reported that synthesized 0D freestanding PbTiO3 nanoparticles (NPs) present negative pressure along the c axis (Δc/cbulk × 100% = -2.406), inducing large spontaneous polarization PS (71.2 µC cm-2 in 12 nm). Further local structural studies by atomic pair distribution functions and extended X-ray absorption fine structure indicate the structural evolution of nanosized PbTiO3 . High-angle annular dark-field STEM images reveal the existence of preponderant PbO-terminations on the surface of the PbTiO3 NPs. Ab initio calculation reveals the enhanced hybridization between Pb and O ions, which gives rise to the negative pressure and tensile stress to stabilize the high tetragonality and large polarization. The present work demonstrates an untraditional route to enhance the ferroelectricity and related properties in functional nanostructured materials, being of significance to nanodevices.

14.
Environ Health Perspect ; 128(10): 107008, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33095664

RESUMO

BACKGROUND: Tetrabromobisphenol A (TBBPA) mono-ether structural analogs, identified as the by-products or transformation products of commercial TBBPA bis-ether derivatives, have been identified as emerging widespread pollutants. However, there is very little information regarding their toxicological effects. OBJECTIVE: We aimed to explore the potential thyroid hormone (TH) system-disrupting effect of TBBPA mono-ether structural analogs. METHODS: The binding potencies of chemicals toward human TH transport proteins [transthyretin (TTR) and thyroxine-binding globulin (TBG)] and receptors [TRα ligand-binding domain (LBD) and TRß-LBD] were determined by fluorescence competitive binding assays. Molecular docking was used to simulate the binding modes of the chemicals with the proteins. The cellular TR-disrupting potencies of chemicals were assessed by a GH3 cell proliferation assay. The intracellular concentrations of the chemicals were measured by high-performance liquid chromatography and mass spectrometry. RESULTS: TBBPA mono-ether structural analogs bound to TTR with half maximal inhibitory concentrations ranging from 0.1µM to 1.0µM but did not bind to TBG. They also bound to both subtypes of TR-LBDs with 20% maximal inhibitory concentrations ranging from 4.0µM to 50.0µM. The docking results showed that the analogs fit into the ligand-binding pockets of TTR and TR-LBDs with binding modes similar to that of TBBPA. These compounds likely induced GH3 cell proliferation via TR [with the lowest effective concentrations (LOECs) ranging from 0.3µM to 2.5µM] and further enhanced TH-induced GH3 cell proliferation (with LOECs ranging from 0.3µM to 1.2µM). Compared with TBBPA, TBBPA-mono(2,3-dibromopropyl ether) showed a 4.18-fold higher GH3 cell proliferation effect and 105-fold higher cell membrane transportation ability. CONCLUSION: This study provided a possible mechanism underlying the difference in TTR or TR binding by novel TBBPA structural analogs. These compounds might exert TH system-disrupting effects by disrupting TH transport in circulation and TR activity in TH-responsive cells. https://doi.org/10.1289/EHP6498.

15.
J Environ Sci (China) ; 98: 31-38, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33097155

RESUMO

High-altitude lake sediment can be used as a natural archive to reconstruct the history of pollutants. In this work, the temporal distribution of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) were determined using a high-resolution gas chromatography coupled with high-resolution mass spectrometer (HRGC/HRMS) in an alpine lake sediment core collected from the southern Tibetan Plateau (TP) to examine whether the expected decreasing trends due to the implementation of the international Conventions could be observed. The concentrations of PCBs and PBDEs in the sediment core were in the range of 11.8-142 pg/g dw and ND-457 pg/g dw, and their fluxes were in the range of 2.51-31.7 ng/(m2·yr) and ND-43.2 ng/(m2·yr), respectively. The prevalence of low-chlorinated (tri-CB) PCBs and low-brominated (tri- to tetra-) PBDEs in most sections of the sediment profiles was observed, suggesting that the light molecular weight PCBs and PBDEs have most likely reached lake sediments by long-range atmospheric transport from distant sources. Despite the restrictions on their applications, the sediment records for the concentrations and fluxes showed no corresponding decreasing trend with restrictions for PCBs, which suggested that these POPs (e.g., PCBs) were still emitted to the environment owing to the influence of primary or secondary emissions. To our knowledge, this is the first report on input history of atmospheric PCBs and PBDEs recorded in TP Lake sediment.


Assuntos
Bifenilos Policlorados , Poluentes Químicos da Água , Monitoramento Ambiental , Sedimentos Geológicos , Éteres Difenil Halogenados/análise , Lagos , Bifenilos Policlorados/análise , Tibet , Poluentes Químicos da Água/análise
16.
Nature ; 586(7829): 390-394, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-33057223

RESUMO

Owing to its high thermal and electrical conductivities, its ductility and its overall non-toxicity1-3, copper is widely used in daily applications and in industry, particularly in anti-oxidation technologies. However, many widespread anti-oxidation techniques, such as alloying and electroplating1,2, often degrade some physical properties (for example, thermal and electrical conductivities and colour) and introduce harmful elements such as chromium and nickel. Although efforts have been made to develop surface passivation technologies using organic molecules, inorganic materials or carbon-based materials as oxidation inhibitors4-12, their large-scale application has had limited success. We have previously reported the solvothermal synthesis of highly air-stable copper nanosheets using formate as a reducing agent13. Here we report that a solvothermal treatment of copper in the presence of sodium formate leads to crystallographic reconstruction of the copper surface and formation of an ultrathin surface coordination layer. We reveal that the surface modification does not affect the electrical or thermal conductivities of the bulk copper, but introduces high oxidation resistance in air, salt spray and alkaline conditions. We also develop a rapid room-temperature electrochemical synthesis protocol, with the resulting materials demonstrating similarly strong passivation performance. We further improve the oxidation resistance of the copper surfaces by introducing alkanethiol ligands to coordinate with steps or defect sites that are not protected by the passivation layer. We demonstrate that the mild treatment conditions make this technology applicable to the preparation of air-stable copper materials in different forms, including foils, nanowires, nanoparticles and bulk pastes. We expect that the technology developed in this work will help to expand the industrial applications of copper.

17.
J Genet Genomics ; 2020 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-33023834

RESUMO

Integration of human papillomavirus (HPV) DNA into the human genome is a reputed key driver of cervical cancer. However, the effects of HPV integration on chromatin structural organization and gene expression are largely unknown. We studied a cohort of 61 samples and identified an integration hot spot in the CCDC106 gene on chromosome 19. We then selected fresh cancer tissue that contained the unique integration loci at CCDC106 with no HPV episomal DNA and performed whole-genome, RNA, chromatin immunoprecipitation and high-throughput chromosome conformation capture (Hi-C) sequencing to identify the mechanisms of HPV integration in cervical carcinogenesis. Molecular analyses indicated that chromosome 19 exhibited significant genomic variation and differential expression densities, with correlation found between three-dimensional (3D) structural change and gene expression. Importantly, HPV integration divided one topologically associated domain (TAD) into two smaller TADs and hijacked an enhancer from PEG3 to CCDC106, with a decrease in PEG3 expression and an increase in CCDC106 expression. This expression dysregulation was further confirmed using 10 samples from our cohort, which exhibited the same HPV-CCDC106 integration. In summary, we found that HPV-CCDC106 integration altered local chromosome architecture and hijacked an enhancer via 3D genome structure remodeling. Thus, this study provides insight into the 3D structural mechanism underlying HPV integration in cervical carcinogenesis.

18.
Environ Pollut ; 267: 115428, 2020 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-32889514

RESUMO

Organophosphate esters (OPEs) were comprehensively investigated in the air samples collected using high-volume samplers near the Chinese Great Wall Station in the Western Antarctic Peninsula over the period of 2014-2018. The concentrations of ∑8OPEs (gaseous + particle phases) ranged from 33.9 to 404 pg/m3 with a geometric mean of 119 ± 12.0 pg/m3. Tris [(2R)-1-chloro-2-propyl] phosphate (TCIPP) and tris(2-chloroethyl) phosphate (TCEP) dominated in the gaseous phase, while tris-n-butyl phosphate (TnBP) was the most abundant OPEs in the particle phase, followed by TCIPP and TCEP. An apparently temporal trend was observed for atmospheric ∑8OPEs over the five years, with a doubling time of about 3.8 years, which indicated continuous inputs of OPEs into the sampling area. The particle-bound ∑8OPEs accounted for 45% of the total, generally lower than that reported in the Arctic. Gas-particle partitioning modeling suggested that the partitioning of OPEs with higher logKOA values approached the steady state in the Antarctic air. The back-trajectory modeling showed that high levels of OPEs were usually associated with air inputs from the northwest of the peninsula. This suggested that long-range transport from South America, which was confirmed by the no temperature dependencies of OPEs concentrations (excluding TnBP). Nevertheless, a steady high level of particle-bound TnBP implied local sources in the Western Antarctic Peninsula, which required further investigation in future works.

19.
J Clin Lab Anal ; : e23567, 2020 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-32909271

RESUMO

BACKGROUND: Treacher Collins syndrome (TCS) is a rare autosomal dominant or recessive disorder, that involves unique bilateral craniofacial malformations. The phenotypes of TCS are extremely diverse. Interventional surgery can improve hearing loss and facial deformity in TCS patients. METHOD: We recruited seven TCS families. Variant screening in probands was performed by targeted next-generation sequencing (NGS). The variants identified were confirmed by Sanger sequencing. The pathogenicity of all the mutations was evaluated using the guidelines of the American College of Medical Genetics and Genomics (ACMG) and InterVar software. RESULTS: Three frameshift variants, two nonsense variants, one missense variant, and one splicing variant of TCOF1 were identified in the seven TCS probands. Five variants including c.1393C > T, c.4111 + 5G>C, c.1142delC, c.2285_2286delCT, and c.1719delG had not been previously reported. Furthermore, we report the c.149A > G variant for the first time in a Chinese TCS patient. We provided prenatal diagnosis for family 4. Proband 7 chose interventional surgery. CONCLUSION: We identified five novel variants in TCOF1 in Chinese patients with TCS, which expands the mutation spectrum of TCOF1 in TCS. Bone conduction hearing rehabilitation can improve hearing for TCS patients and prenatal diagnosis can provide fertility guidance for TCS families.

20.
J Environ Sci (China) ; 97: 180-185, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32933733

RESUMO

Novel brominated flame retardants (NBFRs) were investigated in Arctic air and soil samples collected from Ny-Ålesund and London Island, Svalbard, during Chinese scientific research expeditions to the Arctic during 2014-2015. The concentrations of Σ9NBFRs in the Arctic air and soil were 4.9-8.7 pg/m3 (average 6.8 pg/m3) and 101-201 pg/g dw (average 150 pg/g dw), respectively. The atmospheric concentration of hexabromobenzene (HBB) was significantly correlated with that of pentabromotoluene (PBT) and pentabromobenzene (PBBz), suggesting similar source and environmental fate in the Arctic air. No significant spatial difference was observed among the different sampling sites, both for air and soil samples, indicating that the effects of the scientific research stations on the occurrence of NBFRs in the Arctic were minor. The fugacities from soil to air of pentabromoethylbenzene (PBEB), 2,3-dibromopropyl 2,4,6-tribromophenyl ether (DPTE), and decabromodiphenylethane 1,2-bis (pentabromophenyl) ethane (DBDPE) were lower than the equilibrium value, indicating a nonequilibrium state of these compounds between air and soil, the dominant impact of deposition and the net transport from air to soil. The correlation analysis between the measured and predicted soil-atmosphere coefficients based on the absorption model showed that the impact of the soil organic matter on the distribution of NBFRs in the Arctic region was minor. To the best of our knowledge, this work is one of the limited reports on atmospheric NBFRs in the Arctic and the first study to investigate the occurrence and fate of NBFRs in the Arctic soil.


Assuntos
Retardadores de Chama/análise , Regiões Árticas , Atmosfera , Monitoramento Ambiental , Éteres Difenil Halogenados/análise , Ilhas , Londres , Solo , Svalbard
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