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1.
Langmuir ; 40(35): 18736-18749, 2024 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-39172386

RESUMO

Magnetic polymer microspheres have been extensively utilized as separable and highly efficient adsorbents in wastewater treatment. In this study, a series of novel magnetic spongy porous carbon skeleton materials (Mag-SPCS) have been designed and synthesized by acetonitrile suspension precipitation polymerization, which combines the advantages of the acetonitrile precipitation method and the suspension polymerization method. It was demonstrated that the transformation of the material morphology from microspheres to a porous sponge was achieved by a gradual decrease in the usage amount of ethylene glycol. After N,N-dimethyloctadecylamine (C18) was grafted onto the Mag-SPCS materials, the C18-Mag-SPCS materials with a superhigh saturation adsorption capacity and superfast adsorption efficiency were used for the removal of BTEX (toluene, benzene, and para-xylene) in wastewater. Subsequently, the adsorption properties of the composites with different morphologies were evaluated, and the effect of the usage amount of C18 on the adsorption properties of the C18-Mag-SPCS was further investigated. The maximum adsorption capacities of C18-Mag-SPCS for benzene, toluene, and para-xylene were 714.84, 564.32, and 394.48 mg/g, respectively. The adsorption process was conducted in accordance with the proposed secondary and Langmuir models. Finally, the FTIR, XPS, and XRD characterization results before and after adsorption demonstrated that the adsorption mechanism of toluene onto C18-Mag-SPCS was primarily hydrogen bonding, π-π stacking, and van der Waals forces. These findings of the study indicate that the composite material exhibits an ultrahigh saturation adsorption capacity and ultrafast adsorption efficiency, thereby confirming its considerable potential for application in wastewater treatment.

2.
Methods ; 220: 106-114, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37972913

RESUMO

Discovering new indications for existing drugs is a promising development strategy at various stages of drug research and development. However, most of them complete their tasks by constructing a variety of heterogeneous networks without considering available higher-order connectivity patterns in heterogeneous biological information networks, which are believed to be useful for improving the accuracy of new drug discovering. To this end, we propose a computational-based model, called SFRLDDA, for drug-disease association prediction by using semantic graph and function similarity representation learning. Specifically, SFRLDDA first integrates a heterogeneous information network (HIN) by drug-disease, drug-protein, protein-disease associations, and their biological knowledge. Second, different representation learning strategies are applied to obtain the feature representations of drugs and diseases from different perspectives over semantic graph and function similarity graphs constructed, respectively. At last, a Random Forest classifier is incorporated by SFRLDDA to discover potential drug-disease associations (DDAs). Experimental results demonstrate that SFRLDDA yields a best performance when compared with other state-of-the-art models on three benchmark datasets. Moreover, case studies also indicate that the simultaneous consideration of semantic graph and function similarity of drugs and diseases in the HIN allows SFRLDDA to precisely predict DDAs in a more comprehensive manner.


Assuntos
Algoritmos , Semântica , Serviços de Informação
3.
Phys Chem Chem Phys ; 26(31): 21052-21060, 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39054907

RESUMO

In this work, a mixed precursor solvent system comprising isopropyl alcohol (IPA) and 2-methoxy ethanol (MOE) is introduced for the fabrication of Cu2ZnSn(S, Se)4 (CZTSSe) thin films under ambient conditions. The effects of different IPA/(MOE + IPA) ratios on the characteristics of CZTSSe films and the corresponding devices were investigated. Our research results indicate that the addition of IPA enhances the wettability of Cu-Zn-Sn-S precursor solution on the substrate, reduces Sn loss in the film during high-temperature annealing, and diminishes band tail states. Additionally, adding IPA leads to effective enlargement of grain size, improved crystallinity, and enhanced light absorption. However, excessive content of IPA negatively impacts CZTSSe film properties and the device's performance. Notably, when substituting 20% of MOE with IPA, the short-circuit current density (JSC) increased from 30.84 mA cm-2 to 35.55 mA cm-2 in the resulting CZTSSe device, and the efficiency improved from 9.19% to 10.63%. This work provides a new method of a solvent system for preparing efficient kesterite-based solar cells.

4.
J Environ Manage ; 366: 121807, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39025011

RESUMO

The removal of various pollutants from water is necessary due to the increasing requirements for the removal of various pollutants from wastewater and the quality of drinking water. Polymer microspheres are regarded as exemplary adsorbent materials due to their high adsorption efficiency, excellent adsorption performance, and ease of handling. Herein, the advantages and disadvantages of different preparation methods, modifications, applications and the current research status of polymer microspheres are summarized at large. Furthermore, the enhanced performance of modified composite microspheres is emphasized, including adsorption efficiency, thermal stability, and significant improvements in physical and chemical properties. Subsequently, the current applications and potential of polymeric microspheres for wastewater treatment, including the removal of inorganic and organic pollutants, heavy metal ions, and other contaminants are summarized. Finally, future research directions for polymer microspheres are proposed, outlining the challenges and solutions associated with the application of polymer microspheres in wastewater treatment.


Assuntos
Microesferas , Polímeros , Águas Residuárias , Poluentes Químicos da Água , Purificação da Água , Polímeros/química , Águas Residuárias/química , Purificação da Água/métodos , Adsorção , Poluentes Químicos da Água/química , Metais Pesados/química , Eliminação de Resíduos Líquidos/métodos
5.
Molecules ; 29(15)2024 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-39125079

RESUMO

A novel magnetic nanomaterial with Fe3O4 as the core, PS-DVB as the shell layer, and the surface modified with C18 (C18-PS-DVB-Fe3O4) had been synthesized by seeded emulsion polymerization. C18-PS-DVB-Fe3O4 retains the advantages of the chemical stability, large porosity, and uniform morphology of organic polymers and has the magnetic properties of Fe3O4. A simple, flexible, and efficient magnetic dispersive solid phase extraction (Mag-dSPE) method for the extraction of preservatives, sweeteners, and colorants in river water was established. C18-PS-DVB-Fe3O4 was used as an adsorbent for Mag-dSPE and was coupled with high-performance liquid chromatography (HPLC) to detect 11 food additives: acesulfame, amaranth, benzoic acid, tartrazine, saccharin sodium, sorbic acid, dehydroacetic acid, sunset yellow, allura red, brilliant blue, and erythrosine. Under the optimum extraction conditions, combined with ChromCoreTMAQC18 (5 µm, 4.6 × 250 mm), 20 mmol/L ammonium acetate aqueous solution and methanol were used as mobile phases, and the detection wavelengths were 240 nm and 410 nm. The limits of detection (LODs) of 11 food additives were 0.6-3.1 µg/L with satisfactory recoveries ranging from 86.53% to 106.32%. And the material could be reused for five cycles without much sacrifice of extraction efficiency. The proposed method has been used to determine food additives in river water samples, and results demonstrate the applicability of the proposed C18-PS-DVB-Fe3O4 Mag-dSPE coupled with the HPLC method to environment monitoring analysis.

6.
Molecules ; 29(5)2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38474519

RESUMO

A series of NH2-functionalized nano-sized magnetic metal-organic frameworks (MOFs) were prepared in this study for Cr(VI) removal from wastewater. It was observed that not only the morphological, i.e., orientation growth of N-doped and iron-based metal-organic frameworks, but also the adsorption of magnetic MOFs is largely related to the used amount of ammonium hydroxide in preparation. For example, with increasing amounts of ammonium hydroxide used in preparation, the morphology of magnetic MOFs changed from spherical to cube and triangular cone. Moreover, the maximum adsorption capacity of spherical-magnetic MOFs, cubic-magnetic MOFs and triangular cone-magnetic MOFs could be up to 204.08 mg/g, 232.56 mg/g and 270.27 mg/g, respectively. Under optimal conditions, the adsorption process of magnetic MOFs for Cr(VI) was consistent with the pseudo-second-order rate equation (R2 = 1) and Langmuir isotherm model (R2 > 0.99). Therefore, magnetic MOFs developed in this work offered a viable option for the removal of Cr(VI) from wastewater.

7.
Small ; 19(16): e2206083, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36683234

RESUMO

The notorious shuttle effect and sluggish conversion of polysulfides seriously hinder the practical application of Lithium-sulfur (Li-S) batteries. In this study, a novel architecture of MoS2 /MoO3 heterostructure uniformly distributed on carbon nanotubes (MoS2 /MoO3 @CNT) is designed and introduced into Li-S batteries via decorating commercial separator to regulate the redox reactions of polysulfides. Systematic experiments and theoretical calculations showed that the heterostructure not only provides sufficient surface affinity to capture polysulfides and acts as an active catalyst to promote the conversion of polysulfides, but also the highly conductive CNT enables rapid electron/ion migration. As a result, Li-S batteries with the MoS2 /MoO3 @CNT-PP separator deliver an impressive reversible capacity (1015 mAh g-1 at 0.2 A g-1 after 100 cycles), excellent rate capacity (873 mAh g-1 at 5 A g-1 ), and low self-discharge capacity loss (94.6% capacity retention after 7 days of standing). Moreover, even at an elevated temperature of 70 °C, it still exhibits high-capacity retention (800 mAh g-1 at 1 A g-1 after 100 cycles). Encouragingly, when the sulfur load is increased to 8.7 mg cm-2 , the high reversible areal capacity of 6.61 mAh cm-2 can be stably maintained after 100 cycles, indicating a high potential for practical application.

8.
Nano Lett ; 22(12): 4646-4653, 2022 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-35583209

RESUMO

As the core of spintronics, the transport of spin aims at a low-dissipation data process. The pure spin current transmission carried by magnons in antiferromagnetic insulators is natively endowed with superiority such as long-distance propagation and ultrafast speed. However, the traditional control of magnon transport in an antiferromagnet via a magnetic field or temperature variation adds critical inconvenience to practical applications. Controlling magnon transport by electric methods is a promising way to overcome such embarrassment and to promote the development of energy-efficient antiferromagnetic logic. Here, the experimental realization of an electric field-induced piezoelectric strain-controlled magnon spin current transmission through the antiferromagnetic insulator in the Y3Fe5O12/Cr2O3/Pt trilayer is reported. An efficient and nonvolatile manipulation of magnon propagation/blocking is achieved by changing the relative direction between the Néel vector and spin polarization, which is tuned by ferroelastic strain from the piezoelectric substrate. The piezoelectric strain-controlled antiferromagnetic magnon transport opens an avenue for the exploitation of antiferromagnet-based spin/magnon transistors with ultrahigh energy efficiency.

9.
J Neuroradiol ; 50(4): 415-423, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36462648

RESUMO

BACKGROUND AND PURPOSE: Endovascular treatment (EVT) is the best treatment for acute ischemic stroke with large vessel occlusion (LVO) and makes it possible to analyze the blood contents from the occluded vascular compartments. In this study, we attempted to evaluate regional changes in blood gas values and electrolytes in the occluded vessels, aiming to determine whether these changes can predict outcomes in LVO patients receiving EVT. MATERIALS AND METHODS: We prospectively observed 45 consecutive ischemic stroke patients with LVO of the anterior circulation who underwent EVT. We collected the arterial blood proximal to the occlusion site before and after EVT, and the blood within the core of the occluded vascular compartment (distal to the thrombus) and evaluated the labs for blood gas values and electrolytes. Femoral samples were obtained under physiological flow conditions to represent systemic arterial blood. RESULTS: Compared with the femoral arterial blood samples, significant decreases in K+, Ca2+, HCO3-, BE, HCT, tHbc, and TCO2 levels were observed in the proximal luminal blood before EVT. Decreases in K+ and Ca2+ levels were also observed in the proximal luminal blood after EVT. Proximal/femoral ratio of pH and Na+ was associated with short-term clinical outcomes at 72 hours after EVT. A higher proximal/femoral Na+ ratio was associated with successful recanalization. Further analysis after propensity score matching showed significant changes in blood gas and electrolyte among different arterial locations in ICA and MCA LVO participants. Linear regression analyses indicated that the proximal/femoral ratio of pH, Na+, pCO2, HCO3, and TCO2 before EVT were associated with decrease in NIHSS score at 72 hours in ICA-LVO group. CONCLUSIONS: Obvious changes in several parameters of arterial blood gas and electrolyte from the ischemic vasculature occur during hyperacute stroke. Proximal/femoral pH and Na+ ratio before EVT may be associated with short-term clinical outcome, which deserve to be further investigated.


Assuntos
Isquemia Encefálica , Procedimentos Endovasculares , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Cálcio , Trombectomia , Resultado do Tratamento , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/terapia , Acidente Vascular Cerebral/etiologia , Eletrólitos , Procedimentos Endovasculares/efeitos adversos , Artérias , Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/cirurgia
10.
BMC Med ; 20(1): 13, 2022 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-35039035

RESUMO

BACKGROUND: Recaticimab (SHR-1209, a humanized monoclonal antibody against PCSK9) showed robust LDL-C reduction in healthy volunteers. This study aimed to further assess the efficacy and safety of recaticimab in patients with hypercholesterolemia. METHODS: In this randomized, double-blind, placebo-controlled phase 1b/2 trial, patients receiving stable dose of atorvastatin with an LDL-C level of 2.6 mmol/L or higher were randomized in a ratio of 5:1 to subcutaneous injections of recaticimab or placebo at different doses and schedules. Patients were recruited in the order of 75 mg every 4 weeks (75Q4W), 150Q8W, 300Q12W, 150Q4W, 300Q8W, and 450Q12W. The primary endpoint was percentage change in LDL-C from the baseline to end of treatment (i.e., at week 16 for Q4W and Q8W schedule and at week 24 for Q12W schedule). RESULTS: A total of 91 patients were enrolled and received recaticimab and 19 received placebo. The dose of background atorvastatin in all 110 patients was 10 or 20 mg/day. The main baseline LDL-C ranged from 3.360 to 3.759 mmol/L. The least-squares mean percentage reductions in LDL-C from baseline to end of treatment relative to placebo for recaticimab groups at different doses and schedules ranged from -48.37 to -59.51%. No serious treatment-emergent adverse events (TEAEs) occurred. The most common TEAEs included upper respiratory tract infection, increased alanine aminotransferase, increased blood glucose, and increased gamma-glutamyltransferase. CONCLUSION: Recaticimab as add-on to moderate-intensity statin therapy significantly and substantially reduced the LDL-C level with an infrequent administration schedule (even given once every 12 weeks), compared with placebo. TRIAL REGISTRATION: ClinicalTrials.gov , number NCT03944109.


Assuntos
Hipercolesterolemia , Inibidores de PCSK9 , Anticorpos Monoclonais Humanizados/efeitos adversos , Método Duplo-Cego , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/administração & dosagem , Hipercolesterolemia/tratamento farmacológico , Inibidores de PCSK9/efeitos adversos , Resultado do Tratamento
11.
Molecules ; 27(6)2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-35335276

RESUMO

Artificial long-lived radionuclides such as 90Sr and 239,240Pu have been long released into the environment by human nuclear activities, which have a profound impact on the ecological environment. It is of great significance to monitor the concentration of these radionuclides for environmental safety. This paper summarizes and critically discusses the separation and measurement methods for ultra-trace determination of 90Sr, 239Pu, and 240Pu in the environment. After selecting the measurement method, it is necessary to consider the decontamination of the interference from matrix elements and the key elements, and this involves the choice of the separation method. Measurement methods include both radiometric methods and non-radiometric methods. Radiometric methods, including alpha spectroscopy, liquid scintillation spectrometry, etc., are commonly used methods for measuring 239+240Pu and 90Sr. Mass spectrometry, as the representative of non-radiometric measurement methods, has been regarded as the most promising analytical method due to its high absolute sensitivity, low detection limit, and relatively short sample-analysis time. Through the comparison of various measurement methods, the future development trend of radionuclide measurement is prospected in this review. The fully automatic and rapid analysis method is a highlight. The new mass spectrometer with ultra-high sensitivity shows strong analytical capabilities for extremely low concentrations of 90Sr, 239Pu, and 240Pu, and it is expected to develop determination methods with higher sensitivity and lower detection limit.


Assuntos
Plutônio , Poluentes Radioativos do Solo , Humanos , Radioisótopos/análise , Poluentes Radioativos do Solo/análise , Radioisótopos de Estrôncio/análise
12.
Molecules ; 27(17)2022 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-36080279

RESUMO

In this work, magnetic tetraethylenepentamine (TEPA)-modified carboxyl-carbon nanotubes were synthesized, characterized, and used as adsorbents to conduct magnetic solid-phase extraction (MSPE) for the preconcentration of seven local anesthetic drugs (procaine, lidocaine, mepivacaine, oxybuprocaine, bupivacaine, tetracaine, and cinchocaine) from human plasma. The separation and determination of analytes were performed on high-performance liquid chromatography with UV detection. Several factors affected the extraction efficiency, such as the amount of adsorbents used, extraction time, sample pH, and optimization of elution conditions. Under optimal conditions, satisfactory linear relationships were obtained in the range of 0.02-5.00 mg/L, with the limits of detection (LOD) ranging from 0.003 mg/L to 0.008 mg/L. The recoveries of analytes for spiked human plasma were in the range of 82.0-108%. Moreover, the precision with intra-day and inter-day RSD values were obtained in the range of 1.5-7.7% and 1.5-8.3%. The results indicated that this method could determine the concentration of seven local anesthetic drugs in human plasma with high precision and repeatability and provide support for the clinical monitoring of the concentration of local anesthetic drugs in human plasma.


Assuntos
Anestésicos Locais , Nanotubos de Carbono , Cromatografia Líquida de Alta Pressão/métodos , Humanos , Fenômenos Magnéticos , Extração em Fase Sólida/métodos
13.
Wei Sheng Yan Jiu ; 51(1): 113-117, 2022 Jan.
Artigo em Zh | MEDLINE | ID: mdl-35341506

RESUMO

OBJECTIVE: To investigate the dietary exposure of Ningbo residents to quinolones and tetracyclines antibiotics in animal derived foods, so as to estimate the health risk caused by the exposure. METHODS: Animal derived foods in Ningbo markets from 2018 to 2020 were collected and analyzed by ultra-fast liquid chromatography-tandem mass spectrometry. Based on the result of the measurements, median(M), P97.5, average and the maximum values of the data were obtained. Coupling the food intake data of residents in Zhejiang Province, an international point estimate model was applied to evaluate the health risk caused by the dietary exposure. RESULTS: Enrofloxacin, ciprofloxacin, ofloxacin, doxycycline, oxytetracycline were detected in freshwater fishes, cultured pseudosciaena crocea, freshwater shrimps, chicken, eggs and pork. The detection rates of enrofloxacin, ciprofloxacin, ofloxacin, doxycycline, oxytetracycline were 21.2%(77/363), 11.6%(42/363), 2.8%(10/363), 1.4%(5/363), 0.6%(2/363), respectively. The dietary exposure of adults and children from animal derived foods were in the range of 0.8-909.0 and 0.6-518.9 ng/(kg·d), respectively. The hazard quotient(HQ) values were in the range of 0.000030-0.17. CONCLUSION: Quinolone and tetracycline antibiotics such as enrofloxacin and oxytetracycline have no dietary health risk to the population.


Assuntos
Quinolonas , Ração Animal/análise , Animais , Antibacterianos/análise , Exposição Dietética , Quinolonas/análise , Tetraciclinas/análise
14.
Inorg Chem ; 60(16): 12129-12135, 2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34310114

RESUMO

To date, numerous zirconium cluster-based metal-organic frameworks (Zr-MOFs) with attractive physical properties have been achieved thanks to tailorable organic linkers and versatile Zr clusters. Nevertheless, in comparison with the most-used high-symmetry organic linkers, low-symmetry linkers have rarely been exploited in the construction of Zr-MOFs. Despite challenges in predicting the structure and topology of the MOF, linker desymmetrization presents opportunities for the design of Zr-MOFs with unusual topologies and unexpected functionalities. Herein, we report for the first time the construction of two robust Zr-MOFs (IAM-7 and IAM-8) from two pyrrolo-pyrrole-based low-symmetry tetracarboxylate linkers with a rare rhombic shape. The low symmetry of the linkers arises from the asymmetric pyrrolo-pyrrole core and the varying branch lengths, which play a critical role in the structural diversity between IAM-7 and IAM-8 seen from the structural analysis and lead to hydrophilic channels that contain uncoordinated carboxylate groups in the structure of IAM-7. Furthermore, the proton conductivity of IAM-7 displays a high temperature and humidity dependence where the proton conductivity increases from 2.84 × 10-8 S cm-1 at 30 °C and 40% relative humidity (RH) to 1.42 × 10-2 S cm-1 at 90 °C and 95% RH, making it among one of the most conductive Zr-MOFs. This work not only enriches the library of Zr-MOFs but also offers a platform for the design of low-symmetry linkers toward the structural diversity or irregularity of MOFs as well as their structure-related properties.

15.
Wei Sheng Yan Jiu ; 50(5): 792-798, 2021 Sep.
Artigo em Zh | MEDLINE | ID: mdl-34749874

RESUMO

OBJECTIVE: To develop a method for determination of fipronil and its metabolites in eggs by gas chromatography-tandem mass spectrometry(GC-MS/MS)cleaned with dispersive-solid phase extraction(D-SPE). METHODS: Orthogonal array design with OA16(4~4) matrices was used to optimize the efficiency of D-SPE. The targets were extracted from samples with acetonitrile, and followed by D-SPE cleanup. The extracts were analyzed by GC-MS/MS, and quantified by internal standard method with matrix correction. RESULTS: The calibration curves showed good linearity in the range of 1.0-250.0 µg/L. The correlation coefficients were larger than 0.99.The average recoveries spiked in eggs at the levels of 2 µg/kg, 4 µg/kg and 20 µg/kg were between 87.1% and 125.0%(n=6), and the relative standard deviations were less than 10%. The limits of determination were between 0.1 and 0.4 µg/kg, and the limits of quantitation were between 0.3 and 1.2 µg/kg. CONCLUSION: The method possesses low background, high sensitivity. It can be applied to determine the residues of fipronil and its metabolites in eggs.


Assuntos
Extração em Fase Sólida , Espectrometria de Massas em Tandem , Ovos/análise , Cromatografia Gasosa-Espectrometria de Massas , Pirazóis
16.
Wei Sheng Yan Jiu ; 50(2): 296-300, 2021 Mar.
Artigo em Zh | MEDLINE | ID: mdl-33985640

RESUMO

OBJECTIVE: Ultra-fast liquid chromatography-tandem mass spectrometry method was developed for the analysis of contamination degree of biotoxins in seafood in Ningbo City from 2017 to 2019 and the assessment of dietary exposure was conducted. METHODS: Samples were extracted and purified with optimized pretreatment process and then injected for analysis. According to the result of the measurements, an international point estimate model was used to evaluate the dietary exposure of the population. RESULTS: For tetrodotoxin and 16 shellfish toxins monitored routinely, gonyautoxin5(GTX5), tetrodotoxin and homo-yessotoxin(hYTX) had higher detection rate, other toxins including okadaic acid(OA), dinophysistoxin1(DTX1), decarbamoyl gonyautoxin2(dcGTX2) and decarbamoyl gonyautoxin3(dcGTX3) were detected sporadically. The detection rates of TTX、GTX and hYTX were 27%, 52% and 12%, respectively. The concentration ranges of TTX, GTX and hYTX in polluted samples were 0. 003-0. 535, 0. 008-0. 189 and 0. 032-0. 110 mg/kg. The exposure risk indices(ERI) of TTX, GTX5, hYTX, dcGTX2 and dcGTX3 were 2. 5, 0. 026, 0. 0080, 0. 79 and 0. 32, respectively. CONCLUSION: Marine biotoxins have a lower dietary health risk to the population. It is must be given great attention that in the season of toxic red tide, the detection rates of higher toxic toxins, dcGTX2 and dcGTX3 increased significantly with high risks to human. Moreover, the dietary health risk of tetrodotoxin in routine surveillance in 2019 was higher.


Assuntos
Exposição Dietética , Toxinas Marinhas , Cromatografia Líquida , Humanos , Toxinas Marinhas/análise , Toxinas Marinhas/toxicidade , Ácido Okadáico/análise , Alimentos Marinhos/análise
17.
Anal Chem ; 92(9): 6709-6718, 2020 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-32270673

RESUMO

The atomic ratio of 135Cs/137Cs is a powerful fingerprint for distinguishing the source terms of radioactive contamination and tracing the circulation of water masses in the ocean. However, the determination of the 135Cs/137Cs ratio is very difficult due to the ultratrace level of 135Cs (<0.02 mBq/m3) and 137Cs (<2 Bq/m3) in the ordinary seawater samples. In this work, a sensitive method was developed for determination of 135Cs concentration and 135Cs/137Cs ratio in seawater using chemical separation combined with thermal ionization mass spectrometry (TIMS) measurement. Cesium was first preconcentrated from seawater using ammonium molybdophosphate-polyacrylonitrile column chromatography and then purified using cation exchange chromatography to remove the interferences. With this method, decontamination factors of 6.0 × 106 for barium and 1800 for rubidium and a chemical yield of more than 60% for cesium were achieved. By using glucose as an activator, the ionization efficiency of cesium was significantly improved to 50.6%, and a constant high current of Cs+ (20 V) can be maintained for more than 180 min, which ensures sensitive and reliable measurement of low level 135Cs and 137Cs. Detection limits of 4.0 × 10-17 g/L for both 135Cs and 137Cs for 200 mL seawater were achieved, which enables the accurate determination of 135Cs concentration and 135Cs/137Cs ratio in a small volume of seawater samples (<200 mL). The developed method has been validated by analysis of seawater reference material IAEA-443. Seawater samples collected from the Greenland Sea, Baltic Sea, and Danish Straits have been successfully analyzed for 135Cs concentrations and 135Cs/137Cs ratios, and the results showed that 135Cs concentrations in the seawater of the Baltic Sea is much higher than that in the Greenland Sea, which is attributed to the high deposition of Chernobyl accident derived radiocesium in the Baltic Sea region.

18.
Nat Mater ; 18(9): 931-935, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31285619

RESUMO

Electric field control of spin-orbit torque in ferromagnets1 has been intensively pursued in spintronics to achieve efficient memory and computing devices with ultralow energy consumption. Compared with ferromagnets, antiferromagnets2,3 have huge potential in high-density information storage because of their ultrafast spin dynamics and vanishingly small stray field4-7. However, the manipulation of spin-orbit torque in antiferromagnets using electric fields remains elusive. Here we use ferroelastic strain from piezoelectric materials to switch the uniaxial magnetic anisotropy in antiferromagnetic Mn2Au films with an electric field of only a few kilovolts per centimetre at room temperature. Owing to the uniaxial magnetic anisotropy, we observe an asymmetric Néel spin-orbit torque8,9 in the Mn2Au, which is used to demonstrate an antiferromagnetic ratchet. The asymmetry of the Néel spin-orbit torque and the corresponding antiferromagnetic ratchet can be reversed by the electric field. Our finding sheds light on antiferromagnet-based memories with ultrahigh density and high energy efficiency.

19.
BMC Cancer ; 19(1): 352, 2019 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-30975103

RESUMO

BACKGROUND: High risk human papillomaviruses (HPV) plays important roles in the development of cervical cancer, a number of other anogenital cancer and they are increasingly found in oropharyngeal squamous cell carcinoma (OPSCC), however there has not been comprehensive analysis about the role how these viruses play in the development of OPSCC. METHODS: To characterize the physical status of HPV within OPSCC and to determine the effect this has throughout the host genome, we have performed 30-40X whole genome sequencing (WGS) on the BGI sequencing platform on 34 OPSCCs: 28 of which were HPV positive. We then examined the sequencing data to characterize the HPV copy number and HPV physical status to determine what effect they have on both HPV and human genome structural changes. RESULTS: WGS determined the HPV copy number across the viral genome. HPV copy number ranged from 1 copy to as high as 150 copies in each individual OPSCC. Independent of HPV copy number, most tumors had either a small or a very large deletion in the viral genome. We discovered that these deletions were the result of either HPV integration into the human genome or HPV-HPV sequence junctions. WGS revealed that ~ 70% of these tumors had HPV integrations within the human genome and HPV integration occurred independent of HPV copy number. Individual HPV integrations were found to be highly disruptive resulting in structural variations and copy number changes at or around the integration sites. CONCLUSIONS: WGS reveals that there is a great complexity in both HPV sequences present and the HPV integrations events in HPV positive OPSCCs tumors. Thus HPV may be playing different roles in the development of different OPSCCs and this further challenge the HPV-driven carcinogenesis model first proposed for cervical cancer.


Assuntos
Biomarcadores Tumorais/genética , Carcinoma de Células Escamosas/genética , Neoplasias Orofaríngeas/genética , Papillomaviridae/genética , Infecções por Papillomavirus/genética , Adulto , Idoso , Carcinogênese/genética , Carcinoma de Células Escamosas/patologia , DNA Viral/genética , DNA Viral/isolamento & purificação , Feminino , Dosagem de Genes , Genoma Humano/genética , Genoma Viral/genética , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Orofaríngeas/patologia , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/patologia , Integração Viral/genética , Sequenciamento Completo do Genoma
20.
Inorg Chem ; 58(19): 12748-12755, 2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31497944

RESUMO

Presented herein is a group of highly stable Zr-based metal-organic frameworks with bowl-shaped dihydroanthracene-based tetratopic linkers as building blocks. Structural analysis reveals that these frameworks are all two-dimensional but comprise three distinct connectivities of Zr6 nodes. By using the steric hindrance of the nonplanar linker, the connectivity of Zr6 node can be tuned from 8-c to unusual 4-c. Further, through either one-pot synthesis or postsynthetic linker installation strategies, the connectivity of Zr6 node can be tuned from 8-c to 10-c by the insertion of a secondary linear dicarboxylate linker, from which not only the temperature-dependent flexibility of the structure can be effectively controlled with enhanced rigidity and thermal stability but also a scaffold for postsynthetic metalation of Pd(II) catalyst for Heck coupling reaction is offered.

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