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1.
Huan Jing Ke Xue ; 41(3): 1045-1055, 2020 Mar 08.
Artigo em Chinês | MEDLINE | ID: mdl-32608604

RESUMO

To investigate the variations and sources of n-alkanes and sugars in Taian City during summer, PM2.5 samples were collected from July 22 to August 19, 2016. The identified n-alkane and sugar sources were investigated using a principal component analysis (PCA) multiple linear regression (MLR) model and a backward trajectory model. The results showed that the mass concentrations of PM2.5 during summer were (37.2±11.5) µg·m-3. The mass concentrations of n-alkanes were (83.3±34.7) ng·m-3, the carbon preference index (CPI) was 1.83, and the relative contribution of wax n-alkanes was 34.7%-69.4%, suggesting that contributions from terrestrial plants were more significant in Taian City. The results showed that the mass concentrations of sugars in Taian City during summer were (73.4±46.6) ng·m-3. Levoglucan, galactosan, and mannosan were the main saccharides, accounting for 64.0%, 7.1%, and 6.3% of the total concentrations of sugars, respectively, indicating that biomass burning is much more significant in Taian City. The results of the PCA-MLR model suggested that n-alkanes and sugars in Taian City during summer were mostly from terrestrial plants, coal burning and biomass burning. The backward trajectory model showed that the pollution mostly came from the native sources of Shandong province and the inland cities in the south.

2.
Nat Mater ; 2020 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-32632282

RESUMO

Semimetals are being explored for their unique advantages in low-energy high-speed photodetection, although they suffer from serious drawbacks such as an intrinsically high dark current. In this Perspective, we envision the exploitation of topological effects in the photoresponse of these materials as a promising route to circumvent these problems. We overview recent studies on photodetection based on graphene and other semimetals, and further discuss the opportunities created by topological effects, along with the additional challenges that they impose on photodetector designs.

3.
Biomed Res Int ; 2020: 1052926, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32566649

RESUMO

HpaA as an outer membrane protein of Helicobacter pylori (H. pylori) plays a significant role in the adhesion to the human stomach, but the functional relation between HpaA and gastric epithelial cells is still not clear. To screen the interaction between HpaA and cellular proteins in gastric epithelial cells, the HpaA protein from H. pylori 26695 fused with a tag (6× His) was expressed and purified successfully, the secondary structure was estimated by the Circular Dichroism (CD) spectrum, and the purified recombinant protein was used to perform the pull-down assays with gastric cancer cell lines (AGS and SGC-7901) lysates, respectively. The pull-down proteins were identified by high-performance liquid chromatography tandem mass spectrometry system (HPLC-MS/MS). A total of 9 and 13 proteins related were analyzed from AGS and SGC-7901 cell lysates, respectively. ANXA2 was considered as putative HpaA functional partner discovered from lysates of both cell lines with high score and coverage. It is hypothesized that HpaA may be involved in the biological process of regulation of transcription and nucleic acid metabolism during the adhesion of H. pylori to human gastric epithelial cells, and HpaA-binding proteins also be used as targets for the development of antiadhesion drugs against H. pylori.

4.
Artigo em Inglês | MEDLINE | ID: mdl-32482874

RESUMO

Molecular hydrogen forms the archetypical quantum solid. Its quantum nature is revealed by behavior which is classically impossible and by very strong isotope effects. Isotope effects between [Formula: see text], [Formula: see text], and HD molecules come from mass difference and the different quantum exchange effects: fermionic [Formula: see text] molecules have antisymmetric wavefunctions, while bosonic [Formula: see text] molecules have symmetric wavefunctions, and HD molecules have no exchange symmetry. To investigate how the phase diagram depends on quantum-nuclear effects, we use high-pressure and low-temperature in situ Raman spectroscopy to map out the phase diagrams of [Formula: see text]-HD-[Formula: see text] with various isotope concentrations over a wide pressure-temperature (P-T) range. We find that mixtures of [Formula: see text], HD, and [Formula: see text] behave as an isotopic molecular alloy (ideal solution) and exhibit symmetry-breaking phase transitions between phases I and II and phase III. Surprisingly, all transitions occur at higher pressures for the alloys than either pure [Formula: see text] or [Formula: see text] This runs counter to any quantum effects based on isotope mass but can be explained by quantum trapping of high-kinetic energy states by the exchange interaction.

5.
Am J Physiol Endocrinol Metab ; 319(1): E217-E231, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32516026

RESUMO

We previously demonstrated that circulating extracellular vesicles (EVs) from patients with valvular heart disease (VHD; vEVs) contain inflammatory components and inhibit endothelium-dependent vasodilation. Neutrophil chemotaxis plays a key role in renal dysfunction, and dexmedetomidine (DEX) can reduce renal dysfunction in cardiac surgery. However, the roles of vEVs in neutrophil chemotaxis and effects of DEX on vEVs are unknown. Here, we investigated the impact of vEVs on neutrophil chemotaxis in kidneys and the influence of DEX on vEVs. Circulating EVs were isolated from healthy subjects and patients with VHD. The effects of EVs on chemokine generation, forkhead box protein O3a (FOXO3a) pathway activation and neutrophil chemotaxis on cultured human umbilical vein endothelial cells (HUVECs) and kidneys in mice and the influence of DEX on EVs were detected. vEVs increased FOXO3a expression, decreased phosphorylation of Akt and FOXO3a, promoted FOXO3a nuclear translocation, and activated the FOXO3a signaling pathway in vitro. DEX pretreatment reduced vEV-induced CXCL4 and CCL5 expression and neutrophil chemotaxis in cultured HUVECs via the FOXO3a signaling pathway. vEVs were also found to suppress Akt phosphorylation and activate FOXO3a signaling to increase plasma levels of CXCL4 and CCL5 and neutrophil accumulation in kidney. The overall mechanism was inhibited in vivo with DEX pretreatment. Our data demonstrated that vEVs induced CXCL4-CCL5 to stimulate neutrophil infiltration in kidney, which can be inhibited by DEX via the FOXO3a signaling. Our findings reveal a unique mechanism involving vEVs in inducing neutrophils chemotaxis and may provide a novel basis for using DEX in reducing renal dysfunction in valvular heart surgery.

6.
ACS Nano ; 2020 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-32496750

RESUMO

It has recently been shown that quantum-confined states can appear in epitaxially grown van der Waals material heterobilayers without a rotational misalignment (θ = 0°), associated with flat bands in the Brillouin zone of the moiré pattern formed due to the lattice mismatch of the two layers. Peaks in the local density of states and confinement in a MoS2/WSe2 system was qualitatively described only considering local stacking arrangements, which cause band edge energies to vary spatially. In this work, we report the presence of large in-plane strain variation across the moiré unit cell of a θ = 0° MoS2/WSe2 heterobilayer and show that inclusion of strain variation and out-of-plane displacement in density functional theory calculations greatly improves their agreement with the experimental data. We further explore the role of a twist angle by showing experimental data for a twisted MoS2/WSe2 heterobilayer structure with a twist angle of θ = 15°, which exhibits a moiré pattern but no confinement.

7.
Sheng Li Xue Bao ; 72(3): 308-324, 2020 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-32572429

RESUMO

Gut injury continues to be the devastating and unpredictable critical illness associated with increased cell death of intestinal epithelial cells (IECs). The IECs, immune system and microbiome are the interrelated entities to maintain normal intestinal homeostasis and barrier integrity. In response to microbial invasion, IEC cell death occurs to maintain intestinal epithelium function and retain the continuous renewal and tissue homeostasis. But the imbalance of IEC cell death results in increased intestinal permeability and barrier dysfunction that leads to several acute and chronic intestinal diseases, such as intestinal ischemia/reperfusion (I/R), sepsis, inflammatory bowel diseases (IBD), necrotizing enterocolitis (NEC), etc. During the pathophysiological state, the excessive IEC apoptotic cell death leads to a chronic inflammatory condition, later switches to necroptotic cell death mechanism that induces more pathological features than apoptosis and may also induce other lytic cell death mechanisms like pyroptosis and ferroptosis to increase the pathogenesis of the intestinal diseases. But still, there remains gaps in the fundamental knowledge about the IEC cell death mechanisms in chronic intestinal diseases. Together, a deep understanding of the specific cell death mechanisms underlying chronic intestinal diseases, including sepsis, IBD, NEC, and intestinal I/R, is desperately needed to develop emerging novel promising therapeutic strategies. This review aims to show how the acute and critical illness in the gut are driven by IEC cell death mechanism, such as apoptosis, necrosis, necroptosis, pyroptosis, and ferroptosis.

8.
Biochemistry ; 59(24): 2226-2236, 2020 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-32469203

RESUMO

The interplay between protein folding and chemical reaction has been an intriguing subject. In this contribution, we report the study of SpyTag and SpyCatcher reactive mutants using a combination of sodium dodecyl sulfate-polyacrylamide gel electrophoresis, liquid chromatography and mass spectrometry, circular dichroism, and NMR spectroscopy. It was found that the wild-type SpyCatcher is well-folded in solution and docks with SpyTag to form an intermediate that promotes isopeptide bond formation. By contrast, the double mutant SpyCatcherVA is disordered in solution yet remains reactive toward SpyTag, forming a well-folded covalent complex. Control experiments using the catalytically inactive mutants further reveal the critical role of the isopeptide bond in stabilizing the otherwise loose SpyTag-SpyCatcherVA complex, amplifying the effect of the minute sequence disparity. We believe that the synergy between protein folding and isopeptide bonding is an effective way to enhance protein stability and engineer protein-protein interactions.

9.
Proc Natl Acad Sci U S A ; 117(20): 11147-11157, 2020 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-32376629

RESUMO

The rhizosphere interaction between plant roots or pathogenic microbes is initiated by mutual exchange of signals. However, how soil pathogens sense host signals is largely unknown. Here, we studied early molecular events associated with host recognition in Fusarium graminearum, an economically important fungal pathogen that can infect both roots and heads of cereal crops. We found that host sensing prior to physical contact with plant roots radically alters the transcriptome and triggers nitric oxide (NO) production in F. graminearum We identified an ankyrin-repeat domain containing protein (FgANK1) required for host-mediated NO production and virulence in F. graminearum In the absence of host plant, FgANK1 resides in the cytoplasm. In response to host signals, FgANK1 translocates to the nucleus and interacts with a zinc finger transcription factor (FgZC1), also required for specific binding to the nitrate reductase (NR) promoter, NO production, and virulence in F. graminearum Our results reveal mechanistic insights into host-recognition strategies employed by soil pathogens.

10.
Eur J Radiol ; 129: 109050, 2020 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-32447147

RESUMO

PURPOSE: To investigate the interobserver agreement of different thyroid imaging report and data system (TI-RADS) and ultrasound (US) features. METHODS: Two researchers independently searched PubMed, Embase and the Web of Science for relevant studies published between October 1972 and December 2018. Studies investigating interobserver agreement between different radiologists were included. The Guidelines for Reporting Reliability and Agreement Studies (GRRAS) and the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) score tools were applied to assess the quality of the studies. The data for the inter-agreements of TI-RADS categories and ultrasound features were extracted, and combined with STATA 12.0 (StataCorp, College Station, TX) was used. RESULTS: Seven studies including 927 patients were eligible for this meta-analysis. There was a moderate variability in the TI-RADS categories among radiologists (0.54; 95% CI: 0.49-0.58). Regarding the US features, the reliability of composition (0.61; 95% CI: 0.55-0.66) and calcification (0.71; 95% CI: 0.65-0.77) was good, the reliability of echogenicity (0.58; 95% CI: 0.51-0.64), shape (0.53; 95% CI: 0.45-0.62), margin (0.40; 95% CI: 0.32-0.48) and echogenic foci (0.43; 95% CI: 0.32-0.54) was moderate. Subgroup analyses showed that experience/training, the number of observers and the number of patients were the main factors influencing the variability. CONCLUSIONS: The interobserver agreement for the TI-RADS categories was moderate. There remains potential for improvement, especially in terms of the echogenicity, shape, margin and echogenic foci, the precision of the description and the targeted training needed.

11.
Sci Rep ; 10(1): 7618, 2020 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-32376883

RESUMO

Surgery followed by adjuvant chemotherapy is a reliable therapy for colon cancer, but is associated with side effects and risks. Recent advancements in nanobioengineering in the form of targeted nanoparticles, cubosomes, liposomes, nanosheets, nanorods, quantum dots have generated substantial advancements in theranostics of colon cancer decreasing the cytotoxic drugs' side effects. We describe a facile mechanism of preparation of hybrid nanocomposite encompassing Au and Ag. Preparation of hybrid nanocomposite is one step process which may be easily escalated. The nanocomposite was characterized using transmission eleactron microscopy, energy dispersive X-Ray spectroscopy, X-ray photoelectron spectroscopy, Fourier transform infra-red spectroscopy, UV-Vis spectroscopy, photoluminescence and cytotoxic studies. In-vivo studies were carried out in Balb/c mice. Photothermal heating experiments in HeLa cells were promising and the characterization studies clearly indicated the formation of hybrid nanocomposite. In-vivo experiments confirmed the efficacy of treatment, along with involvement of epigenetic regulation, which may be helpful in translation from research to clinical applications.

12.
J Med Virol ; 2020 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-32343415

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection causing coronavirus disease 2019 (COVID-19) has spread worldwide. Whether antibodies are important for the adaptive immune responses against SARS-CoV-2 infection needs to be determined. Here, 26 cases of COVID-19 in Jinan, China, were examined and shown to be mild or with common clinical symptoms, and no case of severe symptoms was found among these patients. Strikingly, a subset of these patients had SARS-CoV-2 and virus-specific IgG coexist for an unexpectedly long time, with two cases for up to 50 days. One COVID-19 patient who did not produce any SARS-CoV-2-bound IgG successfully cleared SARS-CoV-2 after 46 days of illness, revealing that without antibody-mediated adaptive immunity, innate immunity alone may still be powerful enough to eliminate SARS-CoV-2. This report may provide a basis for further analysis of both innate and adaptive immunity in SARS-CoV-2 clearance, especially in nonsevere cases.

13.
Theranostics ; 10(9): 4088-4100, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32226541

RESUMO

Human interleukin (IL)-37 is a member of the IL-1 family with potent anti-inflammatory and immunosuppressive properties. Previously, it has been reported that IL-37 suppresses tumor growth and progression. However, the roles of IL-37 in pancreatic cancer development and chemo-resistance remain unknown. Methods: Immunohistochemistry was used to analyze the correlation between IL-37 expression and clinicopathological features of pancreatic ductal adenocarcinoma (PDAC). Western-blot and RT-PCR was used to verify the correlation between IL-37 and hypoxia-inducible factor (HIF)-1α. We performed chromatin immunoprecipitation and luciferase assays to validate HIF-1α suppression of IL-37 expression. Moreover, gain- and loss-of-function studies in vitro and in vivo were used to demonstrate the biological function of IL-37 on PDAC development and chemo-resistance. Results: Our results showed that IL-37 expression was remarkably decreased in PDAC tissues when compared to adjacent normal pancreatic tissues. Reduced IL-37 expression in PDACs was associated with increased PDAC histological grade, tumor size, lymph node metastasis and vessel invasion. IL-37 low patients also have remarkably shorter relapse-free and overall survival. Importantly, IL-37 expression was positively correlated with Gemcitabine efficacy. Mechanistically, HIF-1α attenuated IL-37 transcription by binding to the hypoxia response elements (HREs) in IL-37 promoter. Conversely, IL-37 suppressed HIF-1α expression through STAT3 inhibition. Functionally, downregulation of IL-37 in PDAC cells promoted chemo-resistance, migration and progression in vivo and in vitro. Conclusions: Collectively, our data uncovered IL-37/ STAT3/ HIF-1α negative feedback signaling drives Gemcitabine resistance in PDAC.

14.
Lasers Med Sci ; 2020 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-32277407

RESUMO

The detection and reconstruction of the optical properties within turbid slabs/plate parallel mediums have been widely investigated for its applications in medical diagnosis, atmosphere detection, etc., where the scattering of light would be expected. Although the scattering signal can be utilized for diagnostics purposes, the multiple scattering in the intermediate scattering regime (with an optical depth ~ 2-9) has posed a remarkable challenge. Existing optical tomography methods usually only reconstruct the reduced scattering coefficient to investigate the properties of the scattering target, while reconstruction efforts in analyzing the exact scattering phase function are rare. Solving such issues can provide much more information for proper interpretation of the characteristics of the turbid slab. This work demonstrates an inversion method based on optimization algorithms and the angular distribution of the transmitted light at the entrance plane and the exit plane of the sought medium. Candidate phase functions were pre-calculated and the optimization algorithm is able to reconstruct the phase function spatial distribution of the turbid slab with a satisfactory computational cost. Parametric studies were also performed to analyze the performance of each optimization algorithm used and the sensitivity of this Markov reconstruction scheme to noise.

15.
Zhongguo Zhen Jiu ; 40(4): 352-6, 2020 Apr 12.
Artigo em Chinês | MEDLINE | ID: mdl-32275360

RESUMO

OBJECTIVE: To observe the effect of electronic moxibustion on memory function in the patients with amnestic mild cognitive impairment (aMCI). METHODS: A total of 59 aMCI patients were randomized into an electronic moxibustion group (30 cases) and a placebo moxibustion group (29 cases). In the electronic moxibustion group, the electronic moxibustion was applied to Baihui (GV 20), Dazhui (GV 14), Mingmen (GV 4) and Taixi (KI 3), 45 ℃ in temperature, 20 min each time. The treatment was given once a day, 5 times a week. The treatment for 4 weeks was as one course and 2 courses were required totally. In the placebo moxibustion group, the moxa-free patch was used, 38 ℃ in temperature. The acupoint selection and the treatment frequency were same as the electronic moxibustion group. Before and after treatment, Rivermead behavior memory test (RBMT) was adopted to evaluate the global memory function of the patients in the two groups and the N-back task test was adopted to evaluate working memory function separately. Additionally, the mini-mental state examination (MMSE) and its immediate memory, Montreal cognitive assessment (MoCA) and its delay recall were adopted to evaluate the global cognitive function and memory function. RESULTS: In the electronic moxibustion group, after treatment, RBMT score, N-back accuracy rates, MMSE and MoCA scores and the scores of immediate memory and delay recall were improved significantly as compared with those before treatment (P<0.01). In the placebo moxibustion group, the accuracy rates of 1-back and 2-back task and the scores of immediate memory and delay recall were improved obviously as compared with those before treatment (P<0.05, P<0.01). After treatment, the improvements of RBMT score, the accuracy rates of N-back task and MMSE and MoCA scores in the electronic moxibustion group were higher than those in the placebo moxibustion group (P<0.05). CONCLUSION: Electronic moxibustion improves memory function in the patients with amnestic mild cognitive impairment.

16.
J Agric Food Chem ; 68(16): 4607-4615, 2020 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-32227950

RESUMO

Cry toxins produced by Bacillus thuringiensis are well known for their high insecticidal activities against Lepidoptera, Diptera, and Coleoptera; however, their activities against Aphididae are very low. Recently, it has been reported that a Cry41-related toxin exhibited moderate activity against the aphid Myzus persicae, and thus, it is highly desirable to uncover its unique mechanism. In this paper, we report that Cathepsin B, calcium-transporting ATPase, and symbiotic bacterial-associated protein ATP-dependent-6-phosphofructokinase were pulled down from the homogenate of M. persicae as unique proteins that possibly bound to Cry41-related toxin. Cathepsin B has been reported to cleave and inactivate antiapoptotic proteins and plays a role in caspase-initiated apoptotic cascades. In this study, Cathepsin B was expressed in Escherichia coli and purified, and in vitro interaction between recombinant Cathepsin B and Cry41-related toxin was demonstrated. Interestingly, we found that addition of Cry41-related toxin obviously enhanced Cathepsin B activity. We propose a model for the mechanism of Cry41-related toxin as follows: Cry41-related toxin enters the aphid cells and enhances Cathepsin B activity, resulting in acceleration of apoptosis of aphid cells.

17.
Artigo em Inglês | MEDLINE | ID: mdl-32245813

RESUMO

We report here the pressure-induced amorphization and reversible structural transformation between two amorphous forms of SO2: molecular amorphous and polymeric amorphous, with the transition found at 26 GPa over a broad temperature regime, 77 K to 300 K. The transformation was observed by both Raman spectroscopy and X-ray diffraction in a diamond anvil cell. The results were corroborated by ab initio molecular dynamics simulations, where both forward and reverse transitions were detected, opening a window to detailed analysis of the respective local structures. The high-pressure polymeric amorphous form was found to consist mainly of disordered polymeric chains made of three-coordinated sulfur atoms connected via oxygen atoms, with few residual intact molecules. This study provides an example of polyamorphism in a system consisting of simple molecules with multiple bonds.

18.
Int J Clin Oncol ; 25(6): 1072-1078, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32162011

RESUMO

BACKGROUND: MicroRNAs (miRNAs) are considered as promising cancer biomarkers. The aim of the present study is to investigate the prognostic significance of miR-200c in patients with oral squamous cell carcinoma (OSCC). MATERIALS AND METHODS: Quantitative real-time PCR (qRT-PCR) was used to determine the expression levels of miR-200c in 204 pairs of OSCC and adjacent noncancerous. Correlations between miR-200c expression levels and clinicopathological characteristics were investigated. Survival analysis was performed using the Kaplan-Meier method and log-rank test. Multivariate analysis of the prognostic factors was performed with a Cox proportional hazards regression model. RESULTS: The expression of miR-200c was significantly down-regulated in OSCC tissues compared with adjacent non-tumor tissues (p < 0.0001). Low expression of miR-200c in tumor tissues was significantly correlated with the positive N classification (p = 0.013), advanced TNM stage (p = 0.007) and poor differentiation grade (p = 0.026). Lower miR-200c expression in patients was significantly associated with poor recurrence-free survival (RFS, p = 0.0003) and overall survival (OS, p = 0.0026). Multivariate analysis confirmed that low miR-200c expression was an independent predictor for poor RFS (hazard ratio (HR) 1.705, 95% CI 1.136-2.56, p = 0.01) and OS (HR 1.669, 95% CI 1.03-2.703, p = 0.037) in patients with OSCC. CONCLUSION: Our results suggest that the miR-200c might be a potential prognostic biomarker for OSCC.

19.
Phys Rev Lett ; 124(7): 077401, 2020 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-32142309

RESUMO

We develop a general theory of the layer circular photogalvanic effect (LCPGE) in quasi-two-dimensional chiral bilayers, which refers to the appearance of a polarization-dependent, out-of-plane static dipole moment induced by circularly polarized light. We elucidate the geometric origin of the LCPGE as two types of interlayer coordinate shift weighted by the quantum metric tensor and the Berry curvature, respectively. As a concrete example, we calculate the LCPGE in twisted bilayer graphene, and find that it exhibits a resonance peak whose frequency can be tuned from visible to infrared as the twisting angle varies. The LCPGE thus provides a promising route toward frequency-sensitive, circularly polarized light detection, particularly in the infrared range.

20.
Sci Total Environ ; 718: 137366, 2020 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-32092521

RESUMO

With a high rejection coefficient for trace pharmaceuticals and personal care products (PPCPs), forward osmosis (FO) membrane separation has become a cutting-edge technology in water treatment owing to its low energy consumption and low membrane fouling. Wastewater contains many types of PPCPs, and one pharmaceutical molecule affects the separation behaviors of other pharmaceuticals in FO. Therefore, simultaneous FO of multiple PPCPs needs to be investigated. In this study, the separation behaviors of four trace pharmaceuticals (ciprofloxacin (CIP), sulfamethoxazole (SMX), acetaminophen (ACP), carbamazepine (CBZ)), individually (termed "single pharmaceuticals") and in combination (termed "binary pharmaceuticals" as two pharmaceuticals were studied simultaneously), during FO were investigated at trace concentrations using ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The results showed that for single pharmaceuticals, the molecular sieve dominates their retention rate-the retention rate increases with increasing Stokes radius of the molecules (29.1 â†’ 94.8% for 0.35 â†’ 0.47 nm). For binary pharmaceuticals, the retention rates of both pharmaceuticals without charge decrease with increasing total molecule number (for ACP + CBZ, 31.4 â†’ 52.1% (ACP), 75.1 â†’ 83.0% (CBZ)). Negatively charged pharmaceuticals are mutually exclusive with the negatively charged FO membrane, resulting in the increase of the retention rate of pharmaceuticals (83.1 â†’ 90.1% (CIP) when CIP + ACP â†’ CIP + SMX). In the presence of a positively charged pharmaceutical, the retention rate of negatively charged pharmaceuticals decreases (85.7 â†’ 80.4% (SMX) when SMX + ACP â†’ SMX + CIP) because the positively charged pharmaceutical neutralizes the negative charge on the FO membrane surface, resulting in the weakening of electrostatic repulsion between the negatively charged pharmaceutical and FO membrane surface. The positively charged molecule attracts the negatively charged molecule, forming a couple of molecules with larger molecule weight and increasing the retention rate of the pharmaceuticals (80.4 â†’ 88.2% (SMX) when pH = 7 â†’ 5 for SMX + CIP). The results suggest that the interactions between pharmaceuticals cannot be ignored in the process of removing PPCPs by FO.


Assuntos
Osmose , Purificação da Água , Cromatografia Líquida , Espectrometria de Massas em Tandem , Águas Residuárias
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