24 research outputs found
A meta-analysis and systematic review of randomized controlled trials with degarelix versus gonadotropin-releasing hormone agonists for advanced prostate cancer
Our aim was to systematically evaluate the benefits of degarelix as antagonist versus agonists of gonadotropin-releasing hormones (GnRH) for the treatment of advanced prostate cancer (PC). This comparison was performed either in terms of biochemical or oncological or safety profiles. To this end we, carried out a systematic review and meta-analysis of the literature.We selected only studies directly and prospectively analyzing the two treatments in the same population (randomized phase III studies). We followed the Preferred Reporting Items for Systematic Reviews and meta-analyses process for reporting studies.After we eliminated studies according to the exclusion criteria, 9 publications were considered relevant to this review. These articles described 5 clinical trials that were eligible for inclusion. The follow-up duration in all trials did not exceed 364 days. This meta-analysis and review comprised a total of 1719 men, 1061 randomized to degarelix versus 658 to GnRH agonists treatment for advanced PC. Oncological results were evaluated only in 1 trial (CS21:408 cases) and they were not the primary endpoints of the study. Treatment emerging adverse events were reported in 61.4% and 58.8% of patients in the degarelix and GnRH agonists group, respectively (odds ratio, OR = 1.17; 95% confidence interval, 95% CI: 0.78-1.77, P > 0.1). Treatment related severe cardiovascular side effects were reported (trial CS21-30-35) in 1.6% and 3.6% of patients in the degarelix and GnRH agonists group, respectively (OR = 0.55, 95% CI: 0.26-1.14, P > 0.1).Our analysis evidences relevant limitations in particular for the comparative evaluation of the efficacy and the oncological results related to degarelix
Chronic kidney disease and urological disorders: systematic use of uroflowmetry in nephropathic patients
Background. Chronic kidney disease (CKD) is a highly prevalent condition. Urologic disorders are known causes of CKD, but
often remain undiagnosed and underestimated also for their insidious onset and slow progression. We aimed to evaluate
the prevalence of urological unrecognized diseases in CKD patients by uroflowmetry. Methods. We enrolled consecutive stable CKD outpatients. The patients carried out two questionnaires, the International
Prostate Symptom Score and Incontinence Questionnaire-Short Form, and they also underwent uroflowmetry, evaluating
max flow rate (Qmax), voiding time and voided volume values. Results. A total of 83 patients (43 males, mean age of 59.8613.3 years) were enrolled. Our study showed 28 males and 10
females with a significant reduction of Qmax (P<0.001) while 21 females reported a significant increase of Qmax (P<0.001)
with a prevalence of 49.5% of functional urological disease. Moreover, we showed a significant association between Qmax
and creatinine (PÂĽ0.013), estimated glomerular filtration rate (PÂĽ0.029) and voiding volume (PÂĽ0.05). We have not shown
significant associations with age (PÂĽ0.215), body mass index (PÂĽ0.793), systolic blood pressure (PÂĽ0.642) or diastolic blood
pressure (P¼0.305). Moreover, Pearson’s chi-squared test showed a significant association between Qmax altered with CKD
(v2 ÂĽ1.885, PÂĽ0.170) and recurrent infection (v2ÂĽ8.886, PÂĽ0.012), while we have not shown an association with proteinuria
(v2ÂĽ0.484, PÂĽ0.785), diabetes (v2ÂĽ0.334, PÂĽ0.563) or hypertension (v2ÂĽ1.885, PÂĽ0.170).Conclusions. We showed an elevated prevalence of urological diseases in nephropathic patients; therefore, we suggest to
include uroflowmetry in CKD patient assessment, considering the non-invasiveness, repeatability and low cost of
examination. Uroflowmetry could be used to identify previously unrecognized urological diseases, which may prevent the
onset of CKD or progression to end-stage renal disease and reduce the costs of management
Préparation et caractérisation de zéolithes dopées par des métaux de transition (Mesure de propriétés diélectriques et magnétiques et leur application à la synthèse de composés chimiques sous irradiation microondes)
Cette étude est centrée sur la synthèse et la préparation de zéolithes modifiées par des métaux de transition avec leurs applications en catalyse sous irradiation microondes. Des travaux précédents ont montré l intérêt de modifier des zéolithes avec des métaux de transition pour leur application sur des réactions d oxydation et d utiliser les microondes afin d augmenter les vitesses de réaction. Dans cette thèse, nous avons étudié deux types de structure zéolithique (MEL et FAU) dopés par des métaux de transition (Co, Mn, Fe, Zn, Ni, Cr) à différentes concentrations. Une étude classique de caractérisation a permis d augmenter la connaissance sur la préparation de zéolithes modifiées et de comprendre leur influence sur l activité catalytique. La réaction d oxydation partielle du styrène pour la production du benzaldéhyde a été choisie comme réaction modèle. La zéolithe Co-ZSM-11 a présenté la meilleure activité catalytique dans cette étude ainsi que par rapport à d autres catalyseurs présentés dans la littérature.Les réactions d oxydation du styrène ont été étudiées sous irradiation microondes et sous chauffage conventionnel. Aucune différence sur l activité des zéolithes dopées n a été observée pour les deux types de chauffage. Les faibles valeurs de permittivités et perméabilités des zéolithes dopées par des métaux de transition rendent difficile l intensification du procédé d obtention de benzaldéhyde à partir de l oxydation du styrène sous microondes. Les paramètres de la réaction modèle ont été optimisés et une étude cinétique a été menée avec la zéolithe Co-ZSM-11. Enfin, le chauffage par hystérésis diélectrique a été utilisé dans la synthèse de zéolithes ZSM-11. Le temps de synthèse a été considérablement réduit (80%) par rapport au temps nécessaire sous chauffage conventionnel.This study focuses on the synthesis and preparation of modified zeolites with transition metals and theirs applications in catalysis under microwave irradiation. Previous works have shown interest in modifying zeolites with transition metals for their application to oxidation reactions and in using microwave irradiation in order to increase the reaction rates. In this thesis, we studied two types of zeolite structure (MEL and FAU) doped with transitionmetals (Co, Mn, Fe, Zn, Ni, Cr) at different concentrations. A classic characterization study has increased the knowledge on the preparation of modified zeolites and the understanding of their influence on thecatalytic activity. The styrene partial oxidation reaction for benzaldehyde production was chosen as amodel reaction. Co-ZSM-11 zeolite presented the best catalytic activity in this study and also compared to other catalysts found in the literature. The styrene oxidation reactions were studied under microwave irradiation and under conventional heating. No difference in the activity of doped zeolites was observed for both types of heating. The low values of permittivity and permeability of zeolites doped with transition metals make difficult the intensification of the benzaldehyde production process from styrene oxidation under microwave. The parameters of the model reaction have been optimized and a reaction kinetic study was carried out by using the Co-ZSM-11 zeolite. Finally, the hysteresis dielectric heating was used in the synthesis of ZSM-11. The synthesis time was significantly reduced (80%) under microwave irradiation compared to conventional heating.ROUEN-INSA Madrillet (765752301) / SudocSudocFranceF
Optimized benzaldehyde production over a new Co-ZSM-11 catalyst: Reaction parameters effects and kinetics
International audienceAn efficient Co-ZSM-11 catalyst has been synthesized for benzaldehyde production by the selective styrene oxidation. Reaction parameters such as catalyst mass, reaction temperature, molar ratio styrene/hydrogen peroxide and stirring speed were optimized, by performing the styrene oxidation reaction in a stirred batch system with fine particles of Co-ZSM-11 in suspension under microwave heating. A kinetic study was done by using the initial rate method and the Arrhenius parameters were estimated. This catalyst presents a higher reaction rate about 30% with respect of those found in literature and a higher selectivity towards benzaldehyde about 80% at optimal conditions
Enhancement of synthesis of ZSM-11 zeolite by microwave irradiation
International audienceA novel and complete description for ZSM-11 zeolite microwave-assisted synthesis is provided. The time required for the synthesis of ZSM-11 zeolite was remarkably reduced down to 3–4 days instead of 14 days under classical conditions, without the use of seed crystals and of any pretreatment step such as aging time. The crystallinity degree of ZSM-11 zeolites synthesized under microwave irradiation is considerably improved (39% higher) with respect to the crystallinity of conventional ZSM-11 zeolites. According to SEM images, the particle sizes of ZSM-11 zeolites synthesized by both methods are identical and a new morphology is observed when microwave irradiation is used. The surface area and microporous volume values for both synthesis methods are similar.In this work, the synthesis of ZSM-11 zeolite has been successfully intensified by using microwave irradiation. Energy consumption and synthesis time are considerably reduced
SĂntesis y CaracterizaciĂłn de Zeolitas Mel y Fau Dopadas con Metales de TransiciĂłn para su AplicaciĂłn a la QuĂmica Fina bajo IrradiaciĂłn Microondas
The aim of this work is to obtain zeolites doped with transition metals for their application to the synthesis of chemical compounds under microwave.Microporous zeolites were modified with transition metals. Their crystal structures were verified by XRD. Their specific surfaces were determined by the BET method. The dielectric properties of compacted zeolites were measured using a reflection method. The temperature profiles of these compacted beds were determined under microwave irradiation. Heating phenomena in zeolites were interpreted using a modified Debye model. Lewis and Brönsted acid sites were quantified, and so their acid strength by FTIR of zeolites, after adsorption and desorption of pyridine. Finally, we evaluated the catalytic activity of zeolites in the partial oxidation of styrene, in a batch system, under classical and dielectric heating.El trabajo tiene como objetivo la obtenciĂłn de zeolitas dopadas con metales de transiciĂłn para su aplicaciĂłn a la sĂntesis de compuestos quĂmicos bajo microondas.Se modificaron zeolitas microporosas con metales de transiciĂłn. Su estructura cristalina se verificĂł mediante XRD. Por el mĂ©todo BET se determinĂł el área superficial de cada zeolita. Por medio de un mĂ©todo de reflexiĂłn se midieron las propiedades dielĂ©ctricas de las zeolitas compactadas. Se determinaron los perfiles de temperatura de estos lechos zeolĂticos compactados con calentamiento dielĂ©ctrico. Se interpretaron los fenĂłmenos de calentamiento presentes en las zeolitas mediante el uso del modelo de Debye modificado. Se cuantificaron los sitios ácidos de Lewis y Brönsted y su fuerza ácida mediante FTIR de zeolitas luego de los procesos de adsorciĂłn y desorciĂłn de piridina. Finalmente, se evaluĂł la actividad catalĂtica de zeolitas en la oxidaciĂłn parcial de estireno, en un sistema batch bajo calentamiento clásico y dielĂ©ctrico
Caractérisation diélectrique de zéolithes dopées par des métaux de transition et activité catalytique sous microondes
International audienc
Synthesis and characterization of MEL and FAU zeolites doped with transition metals for their application to the fine chemistry under microwave irradiation
International audienceDoped zeolites with transition metals were prepared for their application to the synthesis of chemical compounds under microwave irradiation. The zeolite crystalline structures were verified by XRD. Their surface areas were determined by the BET method. Lewis and Brönsted acid sites were quantified by FTIR of adsorbed pyridine in zeolites. The characterization of acidic properties revealed the generation of new Lewis acid sites after transition metal incorporation into zeolites. The dielectric properties of compacted zeolites were measured by using a reflection method. The temperature profiles of these compacted beds were measured during heating under microwave irradiation. Heating phenomena in zeolites were interpreted using a modified Debye model. Two main dielectric mechanisms were determined in zeolites: rotational polarization phenomenon and interfacial polarization. The selective catalytic oxidation of styrene with hydrogen peroxide was studied over zeolites doped with transition metals in a batch system, under conventional and microwave heating. Benzaldehyde was the main product in all the samples under study. Styrene conversion showed an important influence of the transition metal nature and content and so, the kind of zeolite structure used. With the present experimental conditions, no difference was proved between microwave and conventional heating neither on activity nor on selectivity
Exploration of marine phytoplankton: From their historical appreciation to the omics era
Marine phytoplankton are believed to account for more than 45% of photosynthetic net primary production on Earth, and hence are at the base of marine food webs and have an enormous impact on the entire Earth system. Their members are found across many of the major clades of the tree of life, including bacteria (cyanobacteria) and multiple eukaryotic lineages that acquired photosynthesis through the process of endosymbiosis. Our understanding of their distribution in marine ecosystems and their contribution to biogeochemical cycles have increased since they were first described in the 18th century. Here, we review historical milestones in marine phytoplankton research and how their roles were gradually understood, with a particular focus on insights derived from large-scale ocean exploration. We start from the first observations made by explorers and naturalists, review the initial identification of the main phytoplankton groups and the appreciation of their function in the influential Kiel and Plymouth schools that established biological oceanography, to finally outline the contribution of modern large-scale initiatives to understand this fundamental biological component of the ocean.Fil: Pierella Karlusich, Juan JosĂ©. Centre National de la Recherche Scientifique. Ecole Normale SupĂ©rieure; Francia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Ibarbalz, Federico Matias. Centre National de la Recherche Scientifique. Ecole Normale SupĂ©rieure; Francia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Centro de Investigaciones del Mar y la AtmĂłsfera. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones del Mar y la AtmĂłsfera; ArgentinaFil: Bowler, Chris. Centre National de la Recherche Scientifique. Ecole Normale SupĂ©rieure; Francia. Centre National de la Recherche Scientifique; Franci
Caractérisation diélectrique de zéolithes dopées par des métaux de transition et activité catalytique sous microondes
International audienc