Three mesoporous silica, SBA-16, SBA-15 and MCM-41, with different structures and porosities were synthesized via a hydrothermal method and their interactions with carbon dioxide (CO
2
) were ...investigated through thermal programmed desorption (TPD) and differential scanning calorimetry. TPD measurements provided precise assessments of the intrinsic affinity towards CO
2
, without the influence of moisture. All silica materials were found to exhibit intrinsic affinity towards carbon dioxide, but the surface basicity, expressed in terms of retained CO
2
amount, is markedly influenced by increases in pore size and framework structures. SBA-15 displayed the highest CRC values, explained in terms of larger pore size, lower numbers of acidic out-of plane Si–OH and higher numbers of much less acidic in-plane silanols. These findings provide valuable information for a better understanding of the role of the silica structure in the intrinsic basicity, prior to further modifications for improving the affinity towards CO
2
or merely for catalysis purposes involving CO
2
as reagents, intermediates or products.
We report the clinical response and biological effects of treatment with rituximab and fludarabine (RF) in five patients with IgM anti‐myelin‐associated glycoprotein (MAG) demyelinating neuropathy. ...Between November 2006 and October 2009, four men and one woman aged 52–85 years received intravenous rituximab at 375 mg/m2 on day 1 and oral fludarabine at 40 mg/m2/day from days 1 to 5, in a treatment cycle that was repeated every month for up to 6 months. Two patients had IgM monoclonal gammopathy of undetermined significance and three low tumor mass Waldenstrom's macroglobulinemia. Four patients showed a major hematological response with a decrease in anti‐MAG titer in three and clearing in one. One patient did not respond. For the responding patients, symptoms and electrophysiological parameters improved significantly. No patient relapsed at post‐RF treatment follow‐up (12–45 months), and no toxicity was reported. The combination of RF induced significant responses in IgM anti‐MAG demyelinating neuropathies, without toxicity. Clinical improvements were correlated to hematological and immunological results.
The CD3-CD4+ aberrant T-cell phenotype is the most described in the lymphoid variant of hypereosinophilic syndrome (L-HES), a rare form of HES. Only a few cases have been reported, and data for these ...patients are scarce. To describe characteristics and outcome of CD3-CD4+ L-HES patients, we conducted a national multicentric retrospective study in the French Eosinophil Network. All patients who met the recent criteria of hypereosinophilia (HE) or HES and who had a persistent CD3-CD4+ T-cell subset on blood T-cell phenotyping were included. Clinical and laboratory data were retrospectively collected by chart review. CD3-CD4+ L-HES was diagnosed in 21 patients (13 females, median age 42 years range, 5–75 yr). Half (48%) had a history of atopic manifestations. Clinical manifestations were dermatologic (81%), superficial adenopathy (62%), rheumatologic (29%), gastrointestinal (24%), pulmonary (19%), neurologic (10%), and cardiovascular (5%). The median absolute CD3-CD4+ T-cell count was 0.35 G/L (range, 0.01–28.3), with a clonal TCRγδ rearrangement in 76% of patients. The mean follow-up duration after HES diagnosis was 6.9 ± 5.1 years. All patients treated with oral corticosteroids (CS) (n = 18) obtained remission, but 16 required CS-sparing treatments. One patient had a T-cell lymphoma 8 years after diagnosis, and 3 deaths occurred during follow-up.In conclusion, clinical manifestations related to CD3-CD4+ T cell-associated L-HES are not limited to skin, and can involve all tissue or organs affected in other types of HE. Contrary to FIP1L1-PDGFRA chronic eosinophilic leukemia patients, CS are always effective in these patients, but CS-sparing treatments are frequently needed. The occurrence of T-cell lymphoma, although rare in our cohort, remains a major concern during follow-up.
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► Reversible capture of CO2 is possible on montmorillonite loaded by polyol compounds. ► The OH groups of the dendrimer were found to act as adsorption sites. ► CO2 adsorbs via weak ...interactions with OH groups of the polyol compounds. ► True reversible retention of CO2 requires high number of weakly basic adsorption sites. ► As compared to amines, CO2 desorbs at lower temperatures from polyol-montmorillonite matrices.
Carbon dioxide (CO2) was reversibly trapped using low cost hybrid matrices obtained through a mere incorporation of organic molecules bearing terminal hydroxyl groups in Na-montmorillonite. For this purpose various organic compounds ranging from bulky Boltorn dendrimers to light molecules like ethylene–glycol were used. At low loadings, the adsorption capacity increased almost proportionally with the number of OH groups. The latter acted as the main adsorption sites. Dendrimer contents exceeding 3wt.% were found to enhance the hydrophobic character of the organic moiety, which aggregates into clusters and reduces the number of accessible sites. Unlike amine-based adsorbents, such matrices displayed weak interaction with CO2, but sufficient adsorption sites to satisfactorily retain CO2. The latter was contacted with adsorbent powder (0.01–0.1mm particle size) at room temperature and normal pressure in the presence of nitrogen. Consecutive measurements through thermal programmed desorption gave CO2 retention capacity (CRC) values in the range 2–14μmolg−1, expressed in terms of CO2 amount desorbed between 20°C and 200°C under a nitrogen throughput of 1–15mL/min. The CRC value was found to be strongly depending on the structure of the incorporated organic molecule and the nitrogen flow rate during impregnation and saturation by CO2 and purge. Increasing the N2 flow rate was found to reduce the CRC value, due to CO2 removal by forced convection. The major part of CO2 can be released at temperature not exceeding 40–70°C or even at room temperature upon exposure to strong nitrogen stream or in CO2-free media. This provides clear evidence of a truly reversible retention of CO2, and opens new prospects for ideal clay-based respiratory membranes bearing other chemical groups, capable to release the adsorbed gas through mere convection by a carrier gas stream, without heating.
This paper focuses on the synthesis of polyol/MCM-48 nanocomposite materials with different percentages of polyalcohol dendrimer H20. The obtained materials were used for CO
2
adsorption. CO
2
-TPD ...analysis showed that the samples containing 1 and 3 wt% of H20 dendrimer have low CO
2
adsorption capacity due to the occupation of active sites, The sample prepared with 0.5 wt% of H20 dendrimer exhibited higher adsorption capacity and thermal stability. The affinity toward CO
2
was found to be mainly due to the presence of organic moiety within the MCM-48 pores.
CO2- and H2O-TPD profile of Na-exchanged omega zeolite
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•Alkali and alkaline-earth exchanged Omega show high surface area and porosity.•Weak Bronsted acidity and high porosity are ...beneficial for Omega-catalyzed MCR.•Alkali cations induce beneficial heterogeneous charge dispersion on zeolite Omega.•Reagents bearing high electron density groups gave low conversion in MCR.•MCR is governed by acid-base interactions of the reactants on Omega surface.
Omega zeolite was synthesized by a hydrothermal method and then modified by ionic exchange using Na, Ca, K, Mg, Co and Cu cations. Analyses through CO2- and H2O-TPD revealed an improvement of the Lewis basicity as compared to the parent zeolite. CO2 adsorption was found to take place on two types of sites: i. strong sites on lattice oxygen located in 12- and 8-ring channels; ii. medium and weak sites located in 12-ring channels involving mainly silanol groups and adsorbed water. Weak Bronsted acidity and high porosity of alkali-exchanged Omega turned out to be essential requirements for high catalytic activity. Such catalysts exhibit heterogeneous charge dispersion but with beneficial effect for catalysis. The lowest conversion yields were registered with reagents bearing high electron density chlorine and/or nitro-groups, which may hinder adsorption at room temperature. MCR processes on Omega turned out to be governed by acid-base interactions between the reactants and zeolite surface.
•CO2 adsorbents are obtained with polyglycerol dendrimers derived from soybean oil.•CO2 adsorbs reversibly on montmorillonite intercalated with polyglycerol dendrimers.•The OH groups of the organic ...moiety behave as the main adsorption sites for CO2.•CO2 adsorbs via weak acid–base interactions with the OH groups.
Three polyglycerol dendrimers with average molecular weights of 500, 1100, and 1700 were obtained starting from glycidol derived from soybean oil. Intercalation of Na-montmorillonite with these dendrimers produced effective organo-Mt adsorbents (NaMt-500, NaMt-1100 and NaMt-1700, respectively) for the reversible capture of CO2. The CO2 retention capacity (QCO2) was assessed through temperature-programmed desorption (TPD), and was found to increase with the number of OH groups incorporated. The latter turned out to be the main adsorption sites. Paradoxically, high dendrimer loadings and larger dendrimer generation did not necessarily raise the amount of adsorbed CO2, because of the formation of dendrimer clusters, which significantly reduces the number of accessible OH groups. The highest QCO2 values were registered for NaMt-1700 (3.88–7.14), NaMt-1100-1 (5.24) and NaMt-500 (11.70–16.42μmolg−1) at loading grades. Such adsorbents can release CO2 at much lower temperatures as compared to amines and other base-like compounds, and turn out to be more suitable for CO2 concentration from major emission sources prior to sequestration or uses in chemical or biological processes. This opens new prospects for the preparation of effective CO2 adsorbents starting from low-cost and ecofriendly materials like clay minerals and hyperbranched polyalcohols deriving from vegetal oils.
V617F JAK2 mutation is a reliable molecular marker of polycythemia vera (PV), potentially useful to monitor the effect of treatments in this disease. In a phase 2 study of pegylated (peg) ...IFN-alpha-2a in PV, we performed prospective sequential quantitative evaluation of the percentage of mutated JAK2 allele (%V617F) by real-time polymerase chain reaction (PCR). The %V617F decreased in 24 (89%) of 27 treated patients, from a mean of 49% to a mean of 27% (mean decrease of 44%; P < .001), and no evidence for a plateau was observed. In one patient, mutant JAK2 was no longer detectable after 12 months. In 3 patients homozygous for the mutation, reappearance of 50% of wild-type allele was observed during treatment. The results seem to confirm the hypothesis that IFN-alpha preferentially targets the malignant clone in PV and show that %V617F assessment using a quantitative method may provide the first tool to monitor minimal residual disease in PV. This trial was registered at www.clinicaltrials.gov as #NCT00241241.
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•Montmorillonite-supported polyalcohols showed improved affinity towards CO2 and water.•The affinity toward water contributes to the CO2 retention capacity.•A higher affinity toward ...CO2 and H2O is obtained with lower dendrimer content.•The operating conditions affects strongly the CRC values.•CO2 can be easily achieved even at room temperature through forced convection.
Polyalcohol incorporation was found to enhance the hydrophilic character of montmorillonite and its affinity towards carbon dioxide. CO2 adsorption occurred in both dry and humid conditions, but higher amounts were retained in the presence of moisture. This suggests two adsorption pathways: 1. direct OHCO2 interaction and 2. more predominantly via indirect ternary OHH2OCO2 interactions. The retained amounts of water and CO2 increased almost proportionally with the number of OH groups incorporated, thus providing clear evidence that these groups act as adsorption sites. The improvement of the CO2 retention capacity (CRC) appears to be also due to the enhancement of the hydrophilic character of the adsorbent. The CRC value was found to strongly depend on the operating conditions. The major part of the retained CO2 was desorbed at 60–70°C from hydrated matrices, but at 20–50°C from dry adsorbents. CO2 can be easily released even at room temperature through forced convection under a gas stream, or under static conditions in dry and CO2-free media, e.g. in the presence of KOH pellets. It results that the CO2 retention also involves physical interactions. These results open new prospects for the reversible capture of other gases on low-cost hybrid adsorbents without thermal regeneration.
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