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1.
Cancer ; 130(14): 2472-2481, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38470375

RESUMO

BACKGROUND: Both venetoclax plus a hypomethylating agent (VEN/HMA) and cytarabine, aclarubicin, and granulocyte colony-stimulating factor (CAG) are low-intensity regimens for older patients with acute myeloid leukemia (AML) that show good efficacy and safety. It is unknown how VEN/HMA compares with the CAG regimen for the treatment of newly diagnosed AML. METHODS: The outcomes of patients with newly diagnosed AML treated with VEN/HMA were compared with those of patients treated with a CAG-based regimen. Propensity score matching between these two cohorts at a 1:1 ratio was performed according to age at diagnosis, sex, Eastern Cooperative Oncology Group performance status, state of fitness, and European LeukemiaNet (ELN) 2022 risk stratification to minimize bias. RESULTS: A total of 84 of 96 patients in the VEN/HMA cohort were matched with 84 of 147 patients in the CAG cohort. VEN/HMA resulted in a better response than the CAG-based regimens, as indicated by a higher composite complete remission (CRc) rate (82.1% vs. 60.7%; p = .002) and minimal residual disease negativity rate (88.2% vs. 68.2%; p = .009). In patients with an ELN adverse risk, VEN/HMA was associated with a higher CRc rate compared to CAG (80.5% vs. 58.3%; p = .006). VEN/HMA was associated with longer event-free survival (EFS) (median EFS, not reached vs. 4.5 months; p = .0004), whereas overall survival (OS) was comparable between the two cohorts (median OS, not reached vs. 18 months; p = .078). CONCLUSIONS: The VEN/HMA regimen may result in a better response than CAG-based treatment in older patients with newly diagnosed AML.


Assuntos
Aclarubicina , Protocolos de Quimioterapia Combinada Antineoplásica , Compostos Bicíclicos Heterocíclicos com Pontes , Citarabina , Fator Estimulador de Colônias de Granulócitos , Leucemia Mieloide Aguda , Pontuação de Propensão , Sulfonamidas , Humanos , Feminino , Masculino , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/mortalidade , Idoso , Citarabina/administração & dosagem , Citarabina/uso terapêutico , Aclarubicina/administração & dosagem , Aclarubicina/uso terapêutico , Pessoa de Meia-Idade , Compostos Bicíclicos Heterocíclicos com Pontes/uso terapêutico , Compostos Bicíclicos Heterocíclicos com Pontes/administração & dosagem , Sulfonamidas/administração & dosagem , Sulfonamidas/uso terapêutico , Fator Estimulador de Colônias de Granulócitos/administração & dosagem , Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Idoso de 80 Anos ou mais
2.
Lipids Health Dis ; 20(1): 171, 2021 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-34838056

RESUMO

BACKGROUND: The effect of comorbid hypertriglyceridemia (HTG) and abdominal obesity (AO) on acute pancreatitis (AP) remains unclear. The aim of this study was to explore the effect of comorbid HTG and AO and discuss which is the dominant disorder. METHODS: In this study, 1219 AP patients who presented with HTG or AO were stratified into four groups: non-HTG + non-AO, HTG + non-AO, non-HTG + AO, and HTG + AO. RESULTS: The 328 patients with comorbid HTG + AO were much younger (42.29 ± 11.77), mainly male (79.57%), and had higher TG levels, larger waist circumferences, and more past medical histories than the patients in the other three non-comorbid groups (P < 0.001). The comorbidity group developed more incidences of persistent organ failure and local complications (P < 0.05). Multivariate logistic regression analysis showed that AO (OR = 3.205, 95% CI = 1.570-6.544), mild HTG (OR = 2.746, 95% CI = 1.125-6.701), and moderate to very severe HTG (OR = 3.649, 95% CI = 1.403-9.493) were independent risk factors for persistent respiratory failure (P < 0.05). Age > 60 years (OR = 1.326, 95% CI = 1.047-1.679), AO (OR = 1.701, 95% CI = 1.308-2.212), diabetes mellitus (OR = 1.551, 95% CI = 1.063-2.261), mild HTG (OR = 1.549, 95% CI = 1.137-2.112), and moderate to very severe HTG (OR = 2.810, 95% CI = 1.926-4.100) were independent risk factors associated with local complications (P < 0.05). Moreover, HTG seemed to be more dangerous than AO. The higher the serum TG level was, the greater the likelihood of persistent respiratory failure and local complications. CONCLUSIONS: Comorbid HTG and AO will aggravate the severity and increase the incidence of local complications of AP. HTG may play a dominant role of risk in the condition of comorbidity. CHINESE CLINICAL TRIAL REGISTRY: ChiCTR2100049566 . Registered on 3rd August, 2021. Retrospectively registered, https://www.chictr.org.cn/edit.aspx?pid=127374&htm=4 .


Assuntos
Hipertrigliceridemia/complicações , Obesidade Abdominal/complicações , Pancreatite/etiologia , Adulto , Fatores Etários , Comorbidade , Feminino , Humanos , Hipertrigliceridemia/epidemiologia , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Obesidade Abdominal/epidemiologia , Pancreatite/epidemiologia , Gravidade do Paciente , Estudos Retrospectivos , Fatores de Risco , Triglicerídeos/sangue
3.
Molecules ; 24(6)2019 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-30934559

RESUMO

Due to the enormous threat of protactinium to the environment and human health, its disposal and chemistry have long been important topics in nuclear science. [PaO(H2O)6]3+ is proposed as the predominant species in hydrous and acidic solutions, but little is known about its formation mechanism. In this study, density functional theory (DFT) calculations demonstrate a water coordination-proton transfer-water dissociation mechanism for the formation of PaO3+ in hydrous solutions. First, Pa(V) ion preferentially forms hydrated complexes with a coordination number of 10. Through hydrogen bonding, water molecules in the second coordination sphere easily capture two protons on the same coordinated H2O ligand to form [PaO(H2O)9]3+. Water dissociation then occurs to generate the final [PaO(H2O)6]3+, which is the thermodynamic product of Pa(V) in hydrous solutions.


Assuntos
Teoria da Densidade Funcional , Íons , Protoactínio/química , Soluções/química , Algoritmos , Humanos , Ligação de Hidrogênio , Modelos Moleculares , Modelos Teóricos , Estrutura Molecular , Termodinâmica
4.
Chemistry ; 24(41): 10324-10328, 2018 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-29897649

RESUMO

Pd-catalyzed Hiyama vinylation reaction of non-activated aryl chlorides and bromides under mild conditions was developed. The use of efficient vinyl donors and electron-rich sterically hindered phosphine ligands was critical for the success of the reaction. The products of this transformation can be used for Am/Cm separation, an important challenge in nuclear fuel reprocessing. The substituent effect on Am/Cm separating selectivity was also achieved, which could contribute to the development of new chromatographic materials for the separation of Am and Cm.

5.
Org Biomol Chem ; 13(9): 2541-5, 2015 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-25598077

RESUMO

A novel "one-pot" reaction was developed for the synthesis of aryl or heteroaryl-substituted amidoxime compounds containing various functional groups. Fluorescence titration experiments coupled with theoretical analysis revealed that the steric hindrance and electronic effects of substituents influence the binding ability of the amidoxime compounds to uranyl ions.

6.
Chemistry ; 20(47): 15334-8, 2014 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-25308802

RESUMO

A copper-catalyzed reductive cross-coupling reaction of nonactivated alkyl tosylates and mesylates with alkyl and aryl bromides was developed. It provides a practical method for efficient and cost-effective construction of aryl-alkyl and alkyl-alkyl CC bonds with stereocontrol from readily available substrates. When used in an intramolecular fashion, the reaction enables convenient access to various substituted carbo- or heterocycles, such as 2,3-dihydrobenzofuran and benzochromene derivatives.

7.
Materials (Basel) ; 17(8)2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38673276

RESUMO

Bismuth telluride (Bi2Te3)-based alloys have been extensively employed in energy harvesting and refrigeration applications for decades. However, commercially produced Bi2Te3-based alloys using the zone-melting (ZM) technique often encounter challenges such as insufficient mechanical properties and susceptibility to cracking, particularly in n-type Bi2Te3-based alloys, which severely limit the application scenarios for bismuth telluride devices. In this work, we seek to enhance the mechanical properties of n-type Bi2Te2.7Se0.3 alloys while preserving their thermoelectrical performance by a mixed mechanism of grain refinement and the TiN composite phase-introduced pinning effect. These nanoscale processes, coupled with the addition of TiN, result in a reduction in grain size. The pinning effects of nano-TiN contribute to increased resistance to crack propagation. Finally, the TiN-dispersed Bi2Te2.7Se0.3 samples demonstrate increased hardness, bending strength and compressive strength, reaching 0.98 GPa, 36.3 MPa and 74 MPa. When compared to the ZM ingots, those represent increments of 181%, 60% and 67%, respectively. Moreover, the thermoelectric performance of the TiN-dispersed Bi2Te2.7Se0.3 samples is identical to the ZM ingots. The samples exhibit a peak dimensionless figure of merit (ZT) value of 0.957 at 375 K, with an average ZT value of 0.89 within the 325-450 K temperature range. This work has significantly enhanced mechanical properties, increasing the adaptability and reliability of bismuth telluride devices for various applications, and the multi-effect modulation of mechanical properties demonstrated in this study can be applied to other thermoelectric material systems.

8.
Talanta ; 262: 124710, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37244244

RESUMO

Methods for Pu determination in water samples has been longtime studied but they generally involved tedious manual operations. In this context, we proposed a novel strategy for accurate determination of ultra-trace Pu in water samples by the combination of fully automated separation with direct ICP-MS/MS measurement. A recently commercialized extraction resin TK200 was used for single-column separation due to its distinctive nature. Acidified waters up to 1 L were directly loaded to the resin at high flow rate (15 mL min-1) with omitting the frequently used co-precipitation process. Small volumes of dilute HNO3 were used for column washing, and Pu was efficiently eluted within only 2 mL 0.5 mol L-1 HCl-0.1 mol L-1 HF with a stable recovery (65%). This separation procedure was fully automated under the control of user program, meanwhile the final eluent was compatible for direct ICP-MS/MS measurement without extra sample treatment. In that way, both the labor intensity and reagent consumption were minimized compared with existing methods. With the high decontamination (104 to 105) of U in the chemical separation and the further elimination of uranium hydrides under oxygen reaction model during ICP-MS/MS measurement, the overall interference yields of UH+/U+ and UH2+/U+ were down to 10-15. The limits of detection (LODs) of this method reached 0.32 µBq L-1 for 239Pu and 2.00 µBq L-1 for 240Pu, which were much lower than those stipulated in the general guidelines for drinking water standards, suggesting this method was promising in routine or emergency radiation monitoring. Furthermore, the established method was successfully applied in a pilot study to determine global fallout derived Pu in surface glacier samples with extremely low concentrations of 239+240Pu, which suggested the method would also be feasible in glacial chronology studies in the future.

9.
J Am Chem Soc ; 134(27): 11124-7, 2012 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-22734716

RESUMO

Practical catalytic cross-coupling of secondary alkyl electrophiles with secondary alkyl nucleophiles under Cu catalysis has been realized. The use of TMEDA and LiOMe is critical for the success of the reaction. This cross-coupling reaction occurs via an S(N)2 mechanism with inversion of configuration and therefore provides a general approach for the stereocontrolled formation of C-C bonds between two tertiary carbons from chiral secondary alcohols.

10.
Angew Chem Int Ed Engl ; 51(2): 528-32, 2012 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-22135233

RESUMO

Easy access: An unprecedented copper-catalyzed cross-coupling reaction of the title compounds with diboron reagents is described (see scheme; Ts = 4-toluenesulfonyl). This reaction can be used to prepare both primary and secondary alkylboronic esters having diverse structures and functional groups. The resulting products would be difficult to access by other means.


Assuntos
Compostos de Boro/síntese química , Cobre/química , Alquilação , Compostos de Boro/química , Catálise , Ésteres/síntese química , Ésteres/química
11.
J Hazard Mater ; 435: 129022, 2022 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-35500348

RESUMO

A major environmental concern related to nuclear energy is wastewater contaminated with uranium, thus necessitating the development of pollutant-reducing materials with efficiency and effectiveness. Herein, highly selective mesoporous silicas functionalized with amine-bridged diacetamide ligands SBA-15-ABDMA were prepared. Different spectroscopy techniques were used to probe the chemical environment and reactivity of the chelating ligands before and after sorption. The results showed that the functionalized SBA-15-ABDMA had a strong affinity for uranium at low pH (pH = 3) with desirable sorption capacity (68.82 mg/g) and good reusability (> 5). It showed excellent separation performance with a high distribution coefficient (Kd,U > 105 mL/g) and separation factors SFU/Ln > 1000 at a pH of 3.5 in the presence of lanthanide nuclides, alkaline earth metal and transition metal ions. In particular, SiO2spheres-ABDMA was used as a column material, which achieved excellent recovery of U(VI) (> 98%) and good reusability for samples of simulated mining and nuclear industries wastewater. XPS and crystallography studies clearly illustrated the tridentate coordination mode of U(VI)/PEABDMA and the mechanism and origin behind the high selectivity for U.


Assuntos
Urânio , Adsorção , Aminas , Ligantes , Dióxido de Silício/química , Urânio/química , Águas Residuárias
12.
Talanta ; 245: 123443, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-35405445

RESUMO

U, Sr, Pb, Nd, and Hf isotope ratios can provide basic and important information of nuclear materials. We established a simple and efficient column chemistry method using nano-NaBiO3, as both oxidizer and adsorbent, to completely separate Ce from rare earth elements (REEs). This new method exhibited a high decontamination (Ce/Nd < 10-5) ability and was easy to conducted, thereby providing clear advantages compared to traditional liquid-liquid and solid phase micro-extraction techniques. Additionally, a rapid four-column separation procedure, based on Sr, TUR, Ln resins and nano-NaBiO3, was developed to isolate U, Sr, Pb, Nd, and Hf in ore samples. The entire procedure could be completed in 4-5 hrs. The robustness of the proposed method was demonstrated by analyzing the 235U/238U, 87Sr/86Sr, 206Pb/204Pb, 207Pb/204Pb, 208Pb/204Pb, 142Nd/144Nd, 143Nd/144Nd, and 176Hf/177Hf isotopic ratios of two certified reference materials (CRMs). The analytical results obtained using this method showed good agreement with previously published data. The feasibility of this method was extended to the determination of isotope ratios in uranium ores. The results obtained from the two samples with different regions indicated that they have different isotopic ratios information. These findings indicate the potential for the use of this new method in nuclear forensic science.


Assuntos
Urânio , Isótopos/análise , Chumbo , Urânio/análise
13.
Cytokine ; 55(2): 174-80, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21565524

RESUMO

Anti-Helicobacter pylori heat shock protein 60 (HpHSP60) antibodies are usually found in H. pylori-infected patients and are known to be associated with the progression of gastric diseases. However, the effects of these antibodies on the functions of HpHSP60 have not been identified. This study aims to investigate the effects of the interaction between anti-HSP60 antibodies and HpHSP60 on inflammatory responses. Anti-HpHSP60 polyclonal sera and monoclonal antibodies (mAbs) were produced to evaluate their effects on HpHSP60-induced IL-8 and TNF-α activity. The results indicated that anti-HpHSP60 polyclonal sera collected from patients infected with H. pylori or from rabbit and mice immunized with HpHSP60 could significantly enhance HpHSP60-mediated IL-8 and TNF-α secretion from monocytic THP-1 cells. Similar effects were also found with anti-HpHSP60 mAbs. Further analysis revealed that this phenomenon was only carried out by anti-HpHSP60 antibody but not by other non-specific mAbs. Moreover, the non-specific mAbs decreased the synergism of HpHSP60 and anti-HpHSP60 mAbs in proinflammatory cytokine induction. Herein, we have examined the role of anti-HpHSP60 antibody in host immune responses for the first time. This study demonstrated that H. pylori HSP60/mAbs could modulate helicobacterial pathogenesis by increasing IL-8 and TNF-α production. The pathogen-specific antibodies may execute potential immune functions rather than recognize or neutralize microbes.


Assuntos
Anticorpos/imunologia , Proteínas de Bactérias/imunologia , Chaperonina 60/imunologia , Helicobacter pylori/imunologia , Inflamação/imunologia , Animais , Linhagem Celular , Feminino , Infecções por Helicobacter/imunologia , Helicobacter pylori/patogenicidade , Humanos , Interleucina-8/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Coelhos , Receptores Fc/imunologia , Transdução de Sinais/imunologia , Fator de Necrose Tumoral alfa/imunologia
14.
J Org Chem ; 76(3): 800-10, 2011 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-21194222

RESUMO

Resin-bound organic ionic bases (RBOIBs) were developed in which tetraalkyl-ammonium or phosphonium cations are covalently attached to solid resins. The application tests showed that the performance of the tetraalkyl-ammonium-type RBOIBs is slightly better than that of the corresponding Cs salts in Cu-catalyzed C-N cross-couplings, while the tetraalkylphosphonium-type RBOIBs are significantly better than all the inorganic bases. With these newly developed RBOIBs, room-temperature Cu-catalyzed C-N coupling with various nonactivated aryl iodides and even aryl bromides can be readily accomplished. Moreover, RBOIBs can be easily recycled and reused for a number of times without much drop of activity. The good performances of RBOIBs are proposed to arise from the relatively weak binding forces between the cationic polymer backbone and basic anions, as opposed to the strong metal-anion interactions in the inorganic bases. Further applications of RBOIBs in Ni-catalyzed Suzuki-type couplings at room temperature, Cu-catalyzed C-N couplings at -30 °C, a Pd-catalyzed Heck reaction at 60 °C, and Cu-catalyzed C-S couplings at room temperature demonstrate that RBOIBs are generally applicable bases with improved performance for many other types of organic transformations.


Assuntos
Carbono/química , Cobre/química , Reagentes de Ligações Cruzadas/química , Íons/química , Sais/química , Aminas/química , Brometos/química , Catálise , Estrutura Molecular , Solventes/química , Temperatura
15.
ACS Appl Mater Interfaces ; 13(1): 1127-1134, 2021 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-33371663

RESUMO

Among various fission products generated in nuclear reactors, xenon and krypton are two important fission gases with high flow, diffusivity, and radioactivity. Moreover, xenon isolated from these products is an expensive industrial resource with wide applications in medicine and lighting, which makes the development of efficient methods for separation of xenon/krypton significant. However, it is usually difficult for xenon/krypton to be adsorbed by chemical adsorbents due to their inert gas properties, and sub-nanoporous adsorbents proven to be workable for the separation of xenon/krypton are still hard to prepare and regulate the pore size. Herein, we report two novel sub-nanoporous covalent organic frameworks (COFs), which were applied to the sieving of xenon/krypton for the first time. The sub-nanoporous COFs were synthesized via aldehyde-amine polycondensation reactions and the subsequent pore size regulation and homogenization process by using a facile, operational, and efficient multiple-site alkylation strategy. Impressively, the as-prepared sub-nanoporous COFs realized the efficient adsorption and sieving of xenon/krypton owing to their slightly larger pore sizes (∼7 Å) than the dynamic diameters of xenon/krypton and their larger pore volumes. The maximum adsorption capacity for xenon is up to 85.6 cm3/g, and the xenon/krypton selectivity can reach to 9.7. Moreover, the as-prepared COFs possess good γ-ray irradiation stability, which endows them with great potentials for the sieving of radioactive xenon/krypton in the practical application. The multiple-site alkylation strategy proposed in this study provides a valuable approach for the pore construction and control of the porous materials, especially the sub-nanoporous adsorption materials.

16.
Pancreas ; 50(10): 1348-1356, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35041332

RESUMO

ABSTRACT: Acute pancreatitis (AP) is a common clinical gastrointestinal disorder with a high mortality rate for severe AP and lacks effective clinical treatment, which leads to considerable comorbidity and financial burden. Traditional Chinese medicine (TCM) has had the unique advantage of treating AP for a long time in China. Clinically, TCM formulas such as Da-cheng-qi decoction, Chai-qin-cheng-qi decoction, Qing-yi decoction, Da-chai-hu decoction, and Da-huang-fu-zi decoction are widely administrated to AP patients. All of these TCM formulas can improve gastrointestinal function, regulate the inflammatory response, and enhance immunity, thus preventing complications, reducing the mortality rate and financial burden. This review will summarize the pharmacological activities and mechanisms of TCM formulas in alleviating AP.


Assuntos
Medicina Tradicional Chinesa/normas , Pancreatite/tratamento farmacológico , Farmacocinética , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/uso terapêutico , Humanos , Medicina Tradicional Chinesa/métodos , Medicina Tradicional Chinesa/estatística & dados numéricos , Pancreatite/fisiopatologia
17.
Nanoscale ; 12(47): 24044-24053, 2020 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-33295920

RESUMO

The separation and recovery of key nuclides such as uranium and plutonium from effluents related to nuclear industry is of great significance for alleviating the shortage of nuclear energy resources and protecting the environment and human health. However, the high temperature, strong acidity and radioactivity of the nuclear effluents pose a severe challenge to the separation materials used in such conditions. The diversity of structure, flexibility of design, and excellent physicochemical stability of covalent organic framework materials (COFs) provide the possibility for the directional design and preparation of adsorbents for use under harsh conditions. Herein, three COFs with similar structure, different pore sizes and connecting modules were synthesized. The ingenious structure predesign enables Dp-COF to have three carboxyl groups oriented toward the pore center and laid out in appropriate spatial positions, which builds hydrogen-bonding bridges between carboxycarbonyl and hydroxyl groups, and thus constructs for the first time a unique COF material with a double-ring pore. The inner pore size of the "double-ring" is slightly larger than the diameter of uranyl hydrate, which leads to a size-matching adsorption of uranium by Dp-COF, thus greatly reducing the effect of protonation. Even in the simulated spent fuel reprocessing liquid with pH = 1.0, the adsorption capacity of Dp-COF for uranium can reach 66.3 mg g-1, and the adsorption capacity reaches 317.3 mg g-1 at pH = 4.5, which is very rare among the reported COFs. More excitingly, the removal rate for uranium reaches up to an unprecedented 99.8% due to the size-matching effect, more than any analogous adsorbents. This study not only proposes new ideas for the design and regulation of the microscopic configuration of COF materials, but also provides an alternative approach for the preparation of efficient uranium adsorbents.

18.
Dalton Trans ; 48(5): 1613-1623, 2019 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-30629054

RESUMO

In recent decades, N-heterocyclic ligands have been extensively used in the separation of lanthanides/actinides, whereas the selective extraction of amercium or curium has been very challenging. Using density functional theory calculations, this study is devoted to the investigation of the binding affinity of a series of modelling pyridine ligands with AmIII and CmIII. The structure-property correlations between the amercium and curium systems and the binding affinity were obtained, and promising strategies for efficient separation of AmIII/CmIII were proposed.

19.
RSC Adv ; 9(24): 13476-13485, 2019 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-35519570

RESUMO

P,P-bis (2-oxooxazolidin-3-yl)-N-(3-(triethoxysilyl)propyl)phosphinic amide (APTES-BOP)-modified SBA-15 (SBA-15-BOP) was prepared by a post-synthesis grafting method for the removal of anionic azo dyes from aqueous solutions. The properties of the prepared adsorbent were characterized by PXRD, FT-IR, SEM, TEM, nitrogen sorption, and elemental analysis. Adsorption equilibrium and adsorption kinetic studies demonstrated that the experimental data fitted well with the Langmuir isotherm model and pseudo-second-order model. According to Langmuir fitting, SBA-15-BOP showed high adsorption capacity for CR and RR2 dyes, with the maximum adsorption capacities of 518.1 mg g-1 and 253.8 mg g-1, respectively. The thermodynamic study indicated that the adsorption processes of CR and RR2 dyes on SBA-15-BOP were spontaneous and exothermal. The prepared SBA-15-BOP can be a promising adsorbent for the removal of anionic dyes from aqueous solutions.

20.
Nanomaterials (Basel) ; 8(3)2018 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-29538348

RESUMO

To aid the design of a hierarchically porous unconventional metal-phosphonate framework (HP-UMPF) for practical radioanalytical separation, a systematic investigation of the hydrolytic stability of bulk phase against acidic corrosion has been carried out for an archetypical HP-UMPF. Bulk dissolution results suggest that aqueous acidity has a more paramount effect on incongruent leaching than the temperature, and the kinetic stability reaches equilibrium by way of an accumulation of a partial leached species on the corrosion conduits. A variation of particle morphology, hierarchical porosity and backbone composition upon corrosion reveals that they are hydrolytically resilient without suffering any great degradation of porous texture, although large aggregates crack into sporadic fractures while the nucleophilic attack of inorganic layers cause the leaching of tin and phosphorus. The remaining selectivity of these HP-UMPFs is dictated by a balance between the elimination of free phosphonate and the exposure of confined phosphonates, thus allowing a real-time tailor of radionuclide sequestration. Moreover, a plausible degradation mechanism has been proposed for the triple progressive dissolution of three-level hierarchical porous structures to elucidate resultant reactivity. These HP-UMPFs are compared with benchmark metal-organic frameworks (MOFs) to obtain a rough grading of hydrolytic stability and two feasible approaches are suggested for enhancing their hydrolytic stability that are intended for real-life separation protocols.

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