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1.
World J Gastroenterol ; 27(35): 5967-5977, 2021 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-34629813

RESUMO

BACKGROUND: Perivascular epithelioid cell tumor (PEComa) is an uncommon tumor of mesenchymal origin. Cases of PEComa in the liver are extremely rare. AIM: To analyze the clinicopathological features and treatment of hepatic PEComa and to evaluate the prognosis after different treatments. METHODS: Clinical and pathological data of 26 patients with hepatic PEComa were collected. All cases were analyzed by immunohistochemistry and clinical follow-up. RESULTS: This study included 17 females and 9 males, with a median age of 50 years. Lesions were located in the left hepatic lobe in 13 cases, in the right lobe in 11, and in the caudate lobe in 2. The median tumor diameter was 6.5 cm. Light microscopy revealed that the tumor cells were mainly composed of epithelioid cells. The cytoplasm contained heterogeneous eosinophilic granules. There were thick-walled blood vessels, around which tumor cells were radially arranged. Immunohistochemical analysis of pigment-derived and myogenic markers in PEComas revealed that 25 cases were HMB45 (+), 23 were Melan-A (+), and 22 SMA (+). TFE3 and Desmin were negative in all cases. All the fluorescence in situ hybridization samples were negative for TFE3 gene break-apart probe. Tumor tissues were collected by extended hepatic lobe resection or simple hepatic tumor resection as the main treatments. Median follow-up was 62.5 mo. None of the patients had metastasis or recurrence, and there were no deaths due to the disease. CONCLUSION: Hepatic PEComa highly expresses melanin and smooth muscle markers, and generally exhibits an inert biological behavior. The prognosis after extended hepatic lobe resection and simple hepatic tumor resection is semblable.


Assuntos
Recidiva Local de Neoplasia , Neoplasias de Células Epitelioides Perivasculares , Gerenciamento Clínico , Feminino , Humanos , Hibridização in Situ Fluorescente , Fígado , Masculino , Pessoa de Meia-Idade , Neoplasias de Células Epitelioides Perivasculares/cirurgia , Prognóstico
2.
World J Gastroenterol ; 27(7): 624-640, 2021 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-33642833

RESUMO

BACKGROUND: The incidence of mixed neuroendocrine-non-neuroendocrine neoplasms (MiNEN) is low. To improve our understanding of this rare tumor type and optimally guide clinical treatment, associated risk factors, clinical manifestations, and prognosis must be explored. AIM: To identify risk factors that influence the prognosis of patients with gastroenteropancreatic MiNEN (GEP-MiNEN). METHODS: We retrospectively analyzed the clinical data of 46 patients who were diagnosed with GEP-MiNEN at the First Affiliated Hospital of Bengbu Medical College (Anhui, China) between January 2013 and December 2017. Risk factors influencing the prognosis of the patients were assessed using Kaplan-Meier curves and cox regression models. We compared the results with 55 randomly selected patients with gastroenteropancreatic GEP neuroendocrine tumors, 47 with neuroendocrine carcinomas (NEC), and 58 with poorly differentiated adenocarcinoma. RESULTS: Among the 46 patients with GEP-MiNEN, thirty-five had gastric tumors, nine had intestinal tumors (four in the small intestine and five in the colon and rectum), and two had pancreatic tumors. The median age of the patients was 66 (41-84) years, and the male-to-female ratio was 2.83. Thirty-three (71.7%) patients had clinical stage III and IV cancers. Distant metastasis occurred in 14 patients, of which 13 had metastasis to the liver. The follow-up period was 11-72 mo, and the median overall survival was 30 mo. Ki-67 index ≥ 50%, high proportion of NEC, lymph node involvement, distant metastasis, and higher clinical stage were independent risk factors affecting the prognosis of patients with GEP-MiNEN. The median overall survival was shorter for patients with NEC than for those with MiNEN (14 mo vs 30 mo, P = 0.001), but did not significantly differ from those with poorly differentiated adenocarcinoma and MiNEN (30 mo vs 18 mo, P = 0.453). CONCLUSION: A poor prognosis is associated with rare, aggressive GEP-MiNEN. Ki-67 index, tumor composition, lymph node involvement, distant metastasis, and clinical stage are important factors for patient prognosis.


Assuntos
Carcinoma Neuroendócrino , Neoplasias Intestinais , Tumores Neuroendócrinos , Neoplasias Pancreáticas , Neoplasias Gástricas , Idoso , Idoso de 80 Anos ou mais , China/epidemiologia , Feminino , Humanos , Neoplasias Intestinais/epidemiologia , Neoplasias Intestinais/terapia , Masculino , Tumores Neuroendócrinos/epidemiologia , Tumores Neuroendócrinos/terapia , Neoplasias Pancreáticas/epidemiologia , Prognóstico , Estudos Retrospectivos , Neoplasias Gástricas/epidemiologia , Neoplasias Gástricas/terapia
3.
Chem Commun (Camb) ; 56(86): 13177-13180, 2020 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-33020765

RESUMO

Metal-catalyzed reductive amination of formyl-containing linkers with N,N-dialkylformamide solvents is concomitant with the solvothermal coordination assembly, leading to novel MOFs functionalized with tertiary aliphatic amino groups. This illustrates a novel one-pot strategy to functionalize MOFs through in situ organic transformation. The UiO-66 MOFs partially functionalized with the amino groups are highly active heterogeneous catalysts for Knoevenagel condensation.

4.
Molecules ; 25(17)2020 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-32859097

RESUMO

The metabolites of the genus Marasmius are diverse, showing good research prospects for finding new bioactive molecules. In order to explore the active metabolites of the fungi Marasmius berteroi, the deep chemical investigation on the bioactive compounds from its cultures was undertaken, which led to the isolation of three new naphthalene compounds dipolynaphthalenes A-B (1,2) and naphthone C (3), as well as 12 known compounds (4-15). Compounds 1, 2, and 4 are dimeric naphthalene compounds. Their structures were elucidated by MS, 1D and 2D NMR spectroscopic data, as well as ECD calculations. Compounds 2-4 and 7 exhibited acetylcholinesterase (AChE) inhibitory activities at the concentration of 50 µg/mL with inhibition ratios of 42.74%, 44.63%, 39.50% and 51.49%, respectively. Compounds 5 and 7,8 showed weak inhibitory activities towards two tumor cell lines, with IC50 of 0.10, 0.076 and 0.058 mM (K562) and 0.13, 0.18, and 0.15 mM (SGC-7901), respectively.


Assuntos
Marasmius/metabolismo , Micélio/metabolismo , Naftalenos/metabolismo
5.
Ther Adv Gastrointest Endosc ; 13: 2631774520925963, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32548578

RESUMO

Anastomotic leakage with abscess is a rare but severe complication of bariatric surgery. However, there is currently a lack of attention regarding this complication. This study aimed to investigate the risk factors for this complication and relevant treatment strategies to call attention to this severe complication. We retrospectively reviewed the patients who were rehospitalized for anastomotic leakage with abscess after bariatric surgeries in West China Hospital of Sichuan University from November 2017 to November 2018. The clinical profiles analyzed included body mass index, body weight before and after surgery, postoperative hospital stay, diet prescriptions, treatment strategies, and outcomes. A total of six patients (two men and four women) were included. The mean baseline body mass index was 37.52 (29.84-43.37), and the mean weight was 104.95 kg (74.5-127.5). The chief complaints leading to rehospitalization were fever and dull abdominal pain. The average postoperative hospital stay was 3.3 (3-4) days, and the onset time ranged from 7 to 15 days. Finally, revision surgeries were performed in two of the six patients (33%), and they were all cured by percutaneous drainage-based treatments. The postoperative fever and abdominal pain were the signs of leakage and abscess. Similar patients should be followed up once a week for 3 weeks after bariatric surgery to facilitate the early recognition of this complication. A longer hospital stay and sufficient parenteral nutrition plus a later implementation of diet should be helpful to minimize this severe complication. Percutaneous drainage played a significant role in the treatment of these patients.

6.
World J Clin Cases ; 8(10): 2016-2022, 2020 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-32518795

RESUMO

BACKGROUND: Liver infarction is a rare necrotic lesion due to the dual blood supply consisting of the hepatic artery and portal vein. The absence of specific clinical manifestations and imaging appearances usually leads to misdiagnosis and poor prognosis. Thus, the precise diagnosis of liver infarction always requires imaging studies, serum studies, and possible liver biopsy. CASE SUMMARY: We report a case of 31-year-old man who developed a huge liver infarction. Persistent right upper abdominal pain and intermittent fever were the main symptoms in this patient. Computed tomography revealed a huge irregular lesion with a maximum diameter of 12.7 cm in the right lobe of the liver. Three-dimensional reconstruction was performed and no significant interruption of the main hepatic vessels was observed. The lesion was initially considered to be a malignant tumor with internal bleeding. Laparoscopic right hepatectomy was performed, and pathology indicated a rare liver infarction. The patient recovered well and was discharged on postoperative day 21. No fever or abnormal liver function were reported in the subsequent 6 mo. CONCLUSION: In patients with a huge liver infarction, early surgical intervention may be beneficial.

7.
Immunology ; 160(2): 209-219, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32149403

RESUMO

CD100 is an immune semaphorin constitutively expressed on T-cells. Matrix metalloproteinase (MMP) is an important mediator of membrane-bound CD100 (mCD100) cleavage to generate soluble CD100 (sCD100), which has immunoregulatory activity in immune cell responses. The aim of the study was to investigate the level and role of sCD100 and mCD100 in modulating CD8+ T-cell function in non-small cell lung cancer (NSCLC). sCD100 and MMP-14 levels in the serum and bronchoalveolar lavage fluid (BALF), and mCD100 expression on peripheral and lung-resident CD8+ T-cells were analysed in NSCLC patients. The ability to induce sCD100 and the effect of MMP-14 on mCD100 shedding for the regulation of non-cytolytic and cytolytic functions of CD8+ T-cells were also analysed in direct and indirect contact co-culture systems. NSCLC patients had lower serum sCD100 and higher mCD100 levels on CD8+ T-cells compared with healthy controls. BALF from the tumour site also had decreased sCD100 and increased mCD100 on CD8+ T-cells compared with the non-tumour site. Recombinant CD100 stimulation enhanced non-cytolytic and cytolytic functions of CD8+ T-cells from NSCLC patients, whereas blockade of CD100 receptor CD72 attenuated CD8+ T-cell activity. NSCLC patients had lower MMP-14 in the serum and in BALF from the tumour site. Recombinant MMP-14 mediated mCD100 shedding from CD8+ T-cell membrane, and led to promotion of CD8+ T-cell response in NSCLC patients. Overall, decreased MMP-14 resulted in insufficient CD100 shedding, leading to suppression of peripheral and lung-resident CD8+ T-cell activity in NSCLC.


Assuntos
Antígenos CD/metabolismo , Linfócitos T CD8-Positivos/imunologia , Carcinoma Pulmonar de Células não Pequenas/imunologia , Neoplasias Pulmonares/imunologia , Metaloproteinase 14 da Matriz/metabolismo , Semaforinas/metabolismo , Adulto , Idoso , Antígenos CD/sangue , Líquido da Lavagem Broncoalveolar/química , Linfócitos T CD8-Positivos/metabolismo , Carcinoma Pulmonar de Células não Pequenas/sangue , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Técnicas de Cocultura , Feminino , Humanos , Pulmão/patologia , Neoplasias Pulmonares/sangue , Neoplasias Pulmonares/patologia , Ativação Linfocitária , Masculino , Metaloproteinase 14 da Matriz/sangue , Pessoa de Meia-Idade , Cultura Primária de Células , Proteínas Recombinantes/metabolismo , Semaforinas/sangue , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Evasão Tumoral , Microambiente Tumoral/imunologia
8.
Huan Jing Ke Xue ; 40(8): 3774-3784, 2019 Aug 08.
Artigo em Chinês | MEDLINE | ID: mdl-31854787

RESUMO

In order to analyze the sources and factors influencing heavy metal pollution in industrial cities, 62 surface layer (0-20 cm) soil samples were collected in Baoji City for analysis using inductively coupled plasma mass spectrometry (ICP-MS). Cd, As, Cu, Pb, Zn, Cr, Mn, and Ni were detected in the samples. Based on geostatistical methods and geo-detector models, the soil heavy metal pollution load index (PLI) was selected as the best indicator of factors affecting heavy metal pollution. The Unmix 6.0 receptor model was also used to analyze the heavy metal source. The results showed that:① The average concentrations of Cd, Pb, Cu, Zn, As, Cr, Mn, and Ni in the surface soils of Baoji City were 0.77 mg·kg-1, 16.75 mg·kg-1, 40.52 mg·kg-1, 261 mg·kg-1, 17.03 mg·kg-1, 49.18 mg·kg-1, 331 mg·kg-1, and 30.52 mg·kg-1, respectively. These values exceeded the national secondary standard for Cd and Zn, which were 8.2 and 3.8 times more abundant, respectively, than in the background soils of Shaanxi Province, indicating that urban soils are seriously polluted with Cd and Zn. The average concentrations of Cu, As, and Ni also exceeded the background levels; ② The total pollution load index (PLIzone) for heavy metals in the surface soils of Baoji City was 1.36, which indicated mild levels of pollution, as analyzed using a geo-detector. Soil texture and distance to the city's railway had the strongest explanatory power for the distribution of pollutants (PD, H=0.040 and 0.026, respectively, with a combined explanatory power of 0.099); ③ Cd, Cu, and As mainly derive from "artificial sources" associated with industrial and agricultural activities, and Zn and Ni derive from traffic emissions. Cr, Pb, and Mn mainly derive from "mixed sources". Overall, the main source of heavy metals in the surface soils of the study area was classified as "mixed source" and soils were classified as having a mild level of pollution. These results provide scientific support for the prevention and control of heavy metal pollution in the soils of Baoji City.

10.
J Microbiol Biotechnol ; 29(3): 454-464, 2019 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-30939631

RESUMO

Salmonellosis is a highly contagious bacterial disease that threatens both human and poultry health. Tests that can detect Salmonella in the field are urgently required to facilitate disease control and for epidemiological investigations. Here, we combined loop-mediated isothermal amplification (LAMP) with a chromatographic lateral flow dipstick (LFD) to rapidly and accurately detect Salmonella. LAMP primers were designed to target the Salmonella invA gene. LAMP conditions were optimized by adjusting the ratio of inner to outer primers, MgSO4 concentration, dNTP mix concentration, amplification temperature, and amplification time. We evaluated the specificity of our novel LAMP-LFD method using six Salmonella species and six related non-Salmonella strains. All six of the Salmonella strains, but none of the non-Salmonella strains, were amplified. LAMP-LFD was sensitive enough to detect concentrations of Salmonella enterica subsp. enterica serovar Pullorum genomic DNA as low as 89 fg/µl, which is 1,000 times more sensitive than conventional PCR. When artificially contaminated feed samples were analyzed, LAMP-LFD was also more sensitive than PCR. Finally, LAMP-LFD gave no false positives across 350 chicken anal swabs. Therefore, our novel LAMP-LFD assay was highly sensitive, specific, convenient, and fast, making it a valuable tool for the early diagnosis and monitoring of Salmonella infection in chickens.


Assuntos
Galinhas/microbiologia , Técnicas de Amplificação de Ácido Nucleico/métodos , Doenças das Aves Domésticas/diagnóstico , Salmonella/isolamento & purificação , Ração Animal/microbiologia , Animais , Proteínas de Bactérias/genética , China , Cromatografia/métodos , Primers do DNA , DNA Bacteriano/análise , DNA Bacteriano/genética , Humanos , Reação em Cadeia da Polimerase/métodos , Doenças das Aves Domésticas/microbiologia , Kit de Reagentes para Diagnóstico , Salmonella/genética , Salmonella/patogenicidade , Salmonella enterica/genética , Salmonella enterica/isolamento & purificação , Salmonella enterica/patogenicidade , Sensibilidade e Especificidade , Fatores de Tempo
11.
Chem Sci ; 10(11): 3307-3314, 2019 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-30996917

RESUMO

The indicator displacement assay (IDA) is for the first time performed within a metal-organic framework (MOF) to achieve ultrasensitive fluorescence turn-on sensing. A Zr(iv) ion MOF (UiO-67-DQ-PsO) furnished with electron-deficient diquat units (DQ2+, as the receptor) on the wall and electron-rich 1-pyrenesulfonate anions (PsO-, as the fluorescent indicator) in the pores was prepared by postsynthetic anion exchange. The MOF is capable of sensing alkylamines owing to the competing PsO--DQ2+ and alkylamine-DQ2+ charge-transfer interactions, the former interaction causing a fluorescence OFF state and the latter displacing PsO- to trigger its emission. Significant advantages have been demonstrated for the IDA inside the MOF. The turn-on assay exhibits much higher sensitivity and anti-interference than the turn-off sensing using the MOF without indicators (the sensitivity is enhanced by as much as six orders of magnitude to the subnanomolar level). The integration of both the receptor and indicator in the porous solid enables facile regeneration and recyclability of the IDA ensemble. Furthermore, we show that the confined space provided by the MOF significantly enhances the supramolecular interactions to make possible the IDA impossible in solution. This work not only demonstrates a novel conceptual approach to fabricate superior fluorescence turn-on sensors using porous materials but also has important implications for supramolecular chemistry in porous materials.

12.
ChemSusChem ; 12(10): 2202-2210, 2019 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-30883018

RESUMO

Ionic metal-organic frameworks (IMOFs) that integrate synergistic Lewis-acid sites (intrinsic metal centers of the frameworks) and nucleophilic anions (halides encapsulated within pores) are intriguing platforms for the design of fully heterogeneous catalytic systems for cycloaddition of CO2 to epoxides. A new, facile and versatile synthetic approach has been used to fabricate triazolium-based IMOFs for the first time. The approach makes use of azide-alkyne click chemistry and subsequent N-alkylation to post-synthetically create a cationic triazolium ring and introduce exchangeable counteranions at the same time. The IMOFs are efficient and recyclable heterogeneous catalysts for CO2 conversion under mild and cocatalyst-free conditions. In particular, the click-accessible triazolium ring provides a handle to incorporate further functionality. The MIL-101-tzmOH-Br catalyst, which integrates hydrogen-bonding hydroxy groups besides metal centers and bromide anions, shows superior catalytic performance under mild conditions.

13.
Int J Surg Case Rep ; 55: 227-229, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30776585

RESUMO

INTRODUCTION: Presently, bariatric surgery is a widespread treatment for obesity and its co-morbidities. Comprehensive evidence from outcomes of bariatric surgery supported that the surgery is safe and effective. However, we should be aware of the multiple risks of bariatric surgery, especially the severe infection at the operation site. CASE PRESENTATION: A 30-year-old woman was hospitalized for anastomotic leakage with abscess after laparoscopic sleeve gastrectomy. After 53 days of percutaneous drainage, absolute diet fasting, parenteral nutrition and culture based antibiotics etc., she was discharged for recovery. DISCUSSION: Theoretically, malabsorption and early diet will increase the risk of anastomotic leakage, but this problem is seldom to be mentioned in related articles. Moreover, it seems to be common that people received bariatric surgery had a relatively short post-operative stay. CONCLUSION: Essential nutritional support, longer post-operative hospital stay and strict follow-up are necessary to minimize this complication.

14.
J Asian Nat Prod Res ; 21(5): 449-455, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-29671341

RESUMO

Chemical investigation on the cultures of the fungus Cordyceps spp., a strain from cell fusion between Cordyceps militaris and Cordyceps cicadae, resulted in the isolation of 13 compounds including 2 new ones named 2-(5-(3-oxobutyl) furan-2-yl) acetic acid (1) and cordycepone (2). Their structures were elucidated from the analysis of 1D/2D NMR and CD data. Among them, compounds 1, 7-9, at a concentration of 50 µg/ml, showed weak inhibitory activity against AChE. Moreover, compounds 6, 9, and 11 showed moderate inhibitory activity against the nematode Panagrellus redivivus with mortality ratio of 79.0, 71.7, and 72.3% at 2.5 mg/ml, respectively.


Assuntos
Fusão Celular , Cordyceps/química , Cordyceps/citologia , Acetilcolinesterase , Animais , Anti-Helmínticos/química , Anti-Helmínticos/farmacologia , Bioensaio , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacologia , Furanos/química , Furanos/metabolismo , Estrutura Molecular , Nematoides/efeitos dos fármacos
15.
World J Clin Cases ; 6(7): 150-155, 2018 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-30079342

RESUMO

Surgery is the first choice of treatment for patients with non-small-cell lung cancer (NSCLC), but few patients can be treated surgically because of either advanced disease or poor pulmonary function. Other therapies include radiotherapy and chemotherapy, as well as complementary and alternative therapies, usually with disappointing results. Bronchial artery infusion (BAI) is a manageable and effective method for treating advanced NSCLC. Outcome is good by BAI due to its repeatability and low toxicity. Icotinib hydrochloride is a newly developed and highly specific epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor and has been safely and efficiently used to treat advanced NSCLC. We herein report a 73-year-old patient with chronic cough, who was diagnosed with advanced NSCLC with the EGFR mutation of L858R substitution in exon 21, and treated with the combination of oral icotinib and BAI chemotherapy as the first-line therapy, which resulted in a satisfactory clinical outcome. Complete remission of advanced NSCLC can be achieved using the combination of oral icotinib and BAI chemotherapy.

16.
Inorg Chem ; 57(12): 6791-6794, 2018 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-29847921

RESUMO

The Mn(II) metal-organic framework with a viologen-based tetracarboxylate ligand exhibits reversible optical (color) and magnetic changes concomitant with stimuli-induced electron transfer from carboxylate to viologen. Compression causes a magnetic transformation from ferro- to ferrimagnetic, while water release/reuptake switches the magnetic behavior between ferro- and antiferromagnetic.

17.
ACS Appl Mater Interfaces ; 10(13): 11056-11062, 2018 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-29546751

RESUMO

The development of selective sensing materials for amine detection has received considerable attentions because amines have high toxicity and exist widely. In this article, we demonstrate for the first time that a degree of discriminative detection of alkylamines can be achieved by a metal-organic coordination material. The material is derived from CdII and 4,4'-bipyridinium-1,1'-bis(phenylene-3-carboxylate), shows 1D channels lined with electron-deficient viologen chromophores, and exhibits different colors upon contact with amine vapors of different molecular sizes and types (primary, secondary, and tertiary). The vapochromism is attributable to electron transfer from the amine group to viologen. The discrimination between amines is because the analyte-receptor interactions, which either directly mediate or indirectly affect electron transfer, are influenced by the number of the N-H bonds in the amine molecule, the size of the amine molecule relative to the receptor channel and the steric hindrance for the electron donor-acceptor contacts. The material also shows reversible photo- and hydrochromism owing to stimuli-induced reversible electron transfer. The compound can be deposited in paper simply by spraying the mixture solution of the starting metal salt and the ligand. The paper can be used as portable test strips for visual and differentiable detection of amines and as erasable inkless printing medium.

18.
Water Sci Technol ; 78(12): 2459-2468, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30767911

RESUMO

A special adsorption of Cu2+ removal is demonstrated using specifically functionalized graphene oxide (GO)/isocyanate (MDI) composites, on which ethylenediamine tetraacetic acid (EDTA) is grafted via amidation and carbamate reaction. The structure and morphology of GO and functionalized composites (EDTA/MDI/GO) were characterized by scanning electron microscope (SEM), Fourier transform infrared spectra (FT-IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Thermogravimetric analysis (TGA). This study investigated the adsorption and desorption behaviors of heavy metal cations and the effects of solution conditions such as pH on Cu2+ removal. The experimental results illustrated that after introducing EDTA and MDI into the GO, the maximum adsorption capacity reached 254.2 ± 10.4 mg/g within 180 min, obviously higher than the GO prepared without these additions (136.5 ± 7.2 mg/g). The EDTA/MDI/GO adsorption kinetics and equilibrium adsorption isotherm fitted the pseudo-second-order kinetic model (R2 = 0.995) and Langmuir isotherm model (R2 = 0.986) well, respectively. Furthermore, EDTA/MDI/GO also displayed good reusability for the efficient removal of Cu2+ after being washed with HCl, suggesting potential application in Cu2+ cleanup.


Assuntos
Cobre/química , Ácido Edético/química , Grafite/química , Isocianatos/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , Adsorção , Cobre/análise , Modelos Químicos , Óxidos , Espectroscopia de Infravermelho com Transformada de Fourier , Poluentes Químicos da Água/análise
19.
ACS Appl Mater Interfaces ; 10(3): 2735-2744, 2018 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-29286627

RESUMO

Metal-organic frameworks (MOFs) are versatile platforms to design switchable and sensory materials responsive to external stimulus. Copuling the electron-deficient bipyridinium chromorphore with the pore structures of MOFs is a nice strategy to design multiresponsive MOFs. Here we present a proof-of-concept study. Postsynthetic N,N'-cycloalkylation of UiO-67-bpy (bpy = 2,2'-bipyridyl) leads to a novel ionic MOF (UiO-67-DQ) functionalized by the electron-deficient diquat (DQ) chromophore. The combination of porosity, cationic character and electron deficiency imparts UiO-67-DQ with versatile responsive properties. It readily undergoes anion exchange, with selective ionochromism associated with charge-transfer (CT) complexation; it is electrochemically active and shows anion-dependent photochromism associated with radical formation through electron transfer (ET); the iono- and photochromism cause efficient luminescence quenching because of energy transfer (EnT) to CT complexes or radicals. The properties of UiO-67-MQ (MQ = N,N'-dimethyl-2,2'-bipyridylium) are also presented for comparison. The CT and ET effects and consequently the EnT efficiency in UiO-67-MQ are weaker than those in UiO-67-DQ because the electron-deficient character is weakened by the severe interannular twist in MQ2+. On the basis of the rich responsive properties, the MOFs are used as sensory and switching materials for facile discrimination of a range of anions, for quantitative detection of I-, and for mimicking of logic operations ranging from simple logic gates to complex integrated logic circuits.

20.
J Phys Chem Lett ; 8(21): 5450-5455, 2017 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-29058901

RESUMO

Stimuli-induced solid-state electron transfer (ET) underlies the use of viologen compounds as responsive materials, but unequivocal structure-property correlations for solid-state ET are still lacking. With different pseudopolymorphic solids derived from N,N'-bis(4-carboxylphenyl)viologen ([H2bcpV]2+), here we report a systematic study on photo- and piezochromic properties associated with ET. We show that the higher the water content in the lattice, the less sensitively the compounds respond to light and pressure. It is proposed that the lattice water does not act as an electron donor but serves to change the ET energetics through its unique polarity and hydrogen bonding capability. The impedimental impact of water on solid-state ET of viologen compounds has not yet been recognized and elucidated prior to this work. The study also suggests that pressure is more powerful than light in inducing ET.

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