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1.
RMD Open ; 10(1)2024 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-38296804

RESUMEN

INTRODUCTION: Colchicine, commonly used in gout flare, is contraindicated in severe chronic kidney disease (CKD) (estimated glomerular filtration rate <30 mL/min). However, in this context, there are few alternatives, and colchicine use persists. We evaluated the tolerance of colchicine and its efficacy in patients with severe CKD. PATIENTS AND METHODS: All prescriptions of colchicine for managing crystal-induced arthritis flare (gout or calcium pyrophosphate deposition (CPPD) disease) in a hospitalised patient with severe CKD were screened from September 2020 to September 2021. After patient consent and treatment information, clinical and biological safety and efficacy data were prospectively collected from day 1 (D1) to D11. RESULTS: We included 54 patients (median age 75 years (IQR 67-83)) with 62 colchicine prescriptions (cases). Twelve (22%) patients were on dialysis. The main reason for hospitalisation was heart failure (31.5%), acute renal failure (22.2%), infection (18.5%) or an acute joint episode (9.3%). In total, 59.3% of patients had diabetes. The prescriptions concerned 58 cases of gout flares, 1 case of CPPD and 3 cases of both. Initial colchicine dosages were ≤0.5 mg/day in 47/62 (75.8%) cases; no dosage exceeded 1 mg/day (median duration of 6 days (IQR 3-11)). Colchicine was well tolerated in 47/61 (77%) cases. No serious adverse event was reported. Colchicine was considered completely effective by the medical team in 48/58 (83%) of cases. CONCLUSION: The use of colchicine, at reduced doses, was mostly effective to treat crystal-induced arthritis flare in 54 patients with severe CKD and was well tolerated, without any serious adverse events.


Asunto(s)
Condrocalcinosis , Gota , Insuficiencia Renal Crónica , Humanos , Anciano , Colchicina/efectos adversos , Gota/complicaciones , Gota/tratamiento farmacológico , Brote de los Síntomas , Condrocalcinosis/inducido químicamente , Condrocalcinosis/tratamiento farmacológico , Insuficiencia Renal Crónica/complicaciones , Insuficiencia Renal Crónica/tratamiento farmacológico
3.
Top Curr Chem (Cham) ; 381(4): 15, 2023 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-37160833

RESUMEN

Hydrogen peroxide is a powerful and green oxidant that allows for the oxidation of a wide span of organic and inorganic substrates in liquid media under mild reaction conditions, and forms only molecular water and oxygen as end products. Hydrogen peroxide is therefore used in a wide range of applications, for which the well-documented and established anthraquinone autoxidation process is by far the dominating production method at the industrial scale. As this method is highly energy consuming and environmentally costly, the search for more sustainable synthesis methods is of high interest. To this end, the article reviews the basis and the recent development of the photocatalytic synthesis of hydrogen peroxide. Different oxygen reduction and water oxidation mechanisms are discussed, as well as several kinetic models, and the influence of the main key reaction parameters is itemized. A large range of photocatalytic materials is reviewed, with emphasis on titania-based photocatalysts and on high-prospect graphitic carbon nitride-based systems that take advantage of advanced bulk and surface synthetic approaches. Strategies for enhancing the performances of solar-driven photocatalysts are reported, and the search for new, alternative, photocatalytic materials is detailed. Finally, the promise of in situ photocatalytic synthesis of hydrogen peroxide for water treatment and organic synthesis is described, as well as its coupling with enzymes and the direct in situ synthesis of other technical peroxides.


Asunto(s)
Peróxido de Hidrógeno , Oxígeno , Peróxidos , Industrias , Cinética
4.
Am J Transplant ; 22(11): 2675-2681, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35713984

RESUMEN

The cilgavimab-tixagevimab combination retains a partial in vitro neutralizing activity against the current SARS-CoV-2 variants of concern (omicron BA.1, BA.1.1, and BA.2). Here, we examined whether preexposure prophylaxis with cilgavimab-tixagevimab can effectively protect kidney transplant recipients (KTRs) against the omicron variant. Of the 416 KTRs who received intramuscular prophylactic injections of 150 mg tixagevimab and 150 mg cilgavimab, 39 (9.4%) developed COVID-19. With the exception of one case, all patients were symptomatic. Hospitalization and admission to an intensive care unit were required for 14 (35.9%) and three patients (7.7%), respectively. Two KTRs died of COVID-19-related acute respiratory distress syndrome. SARS-CoV-2 sequencing was carried out in 15 cases (BA.1, n = 5; BA.1.1, n = 9; BA.2, n = 1). Viral neutralizing activity of the serum against the BA.1 variant was negative in the 12 tested patients, suggesting that this prophylactic strategy does not provide sufficient protection against this variant of concern. In summary, preexposure prophylaxis with cilgavimab-tixagevimab at the dose of 150 mg of each antibody does not adequately protect KTRs against omicron. Further clarification of the optimal dosing can assist in our understanding of how best to harness its protective potential.


Asunto(s)
COVID-19 , Trasplante de Riñón , Humanos , SARS-CoV-2 , Trasplante de Riñón/efectos adversos , Anticuerpos Neutralizantes , Anticuerpos Antivirales
5.
Endocrinol Diabetes Metab ; 5(4): e00281, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35488507

RESUMEN

BACKGROUND: All chronic kidney diseases in diabetic patients are not diabetic kidney diseases. The objective was to compare the clinical characteristics, survival and access to transplantation in diabetic patients starting dialysis and classified either as diabetic kidney disease (DKD) or non-diabetic kidney disease in diabetic patients (NDKD). METHODS: We used the nationwide French REIN registry to analyse baseline clinical characteristics at dialysis inception and outcomes defined as kidney transplantation, deaths and their causes. The probability of death or transplantation was analysed using a multivariate Cox model and the Fine and Gray competing for risk model (sdHT). RESULTS: We included 65,136 patients from January 2009 to December 2015 with a median follow-up of 31 months. The cumulative incidence of kidney transplantation over eight years was 46.9% (44.8-48.9) in non-diabetic patients (ND), higher than the 19.3% (17.5-21.2) in the DKD group and 22.2% (18.4-26.7) in the NDKD group. The risk of death was significantly higher in the NDKD group than in the DKD group, even after accounting for the competing risk of transplantation (NDKD/sdHR 1.22; 95%CI 1.18-1.27; p < 0.005 vs. DKD/sdHR 1.12; 95%CI 1.08-1.16; p < 0.005 with adjustment for age, sex, major adverse cardiovascular events, cancer and chronic respiratory failure, compared to ND). CONCLUSIONS: In diabetic patients starting dialysis, patients in the DKD group had reduced access to kidney transplantation. NDKD patients had a higher risk of mortality than DKD. The distinction between DKD and NDKD should be accounted for in the plan of care of diabetic patients starting dialysis.


Asunto(s)
Diabetes Mellitus Tipo 2 , Nefropatías Diabéticas , Trasplante de Riñón , Estudios de Cohortes , Diabetes Mellitus Tipo 2/complicaciones , Nefropatías Diabéticas/epidemiología , Nefropatías Diabéticas/terapia , Humanos , Diálisis Renal
6.
Int Urol Nephrol ; 54(4): 895-905, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34286472

RESUMEN

BACKGROUND: Residual albuminuria is associated with an increased risk of progression to ESKD. We tested whether a supplementation with native vitamin D could reduce albuminuria in stable CKD patients under maximal renin-angiotensin system (RAS) blockade. METHODS: We conducted a randomized controlled study of high (cholecalciferol 100 000 UI per 10 days over 1 month) vs low-dose (ergocalciferol 400 UI/days over 1 month) supplementation with native vitamin D on urinary albumin/creatinine ratio, blood pressure and the RAS over 1 month in stable CKD patients with albuminuria and maximum tolerated RAS blockade. RESULTS: We included 31 patients, 21 in the high dose group and 10 in the low dose group. In contrast with a low dose, high dose vitamin D normalized plasma 25(OH)D, decreased iPTH but slightly increased plasma phosphate. High dose vitamin D decreased geometric mean UACR from 99.8 mg/mmol (CI 95% 60.4-165.1) to 84.7 mg/mmol (CI 95% 51.7-138.8, p = 0.046). In the low dose group, the change in geometric mean UACR was not significant. Blood pressure, urinary 24 h aldosterone and peaks and AUC of active renin concentrations after acute stimulation by a single dose of 100 mg captopril were unaffected by the supplementation in native vitamin D, irrespective of the dose. Native vitamin D supplementation was well tolerated. CONCLUSIONS: We found a small (- 15%) but significant decrease in albuminuria after high dose vitamin D supplementation. We found no effect of vitamin D repletion on blood pressure and the systemic RAS, concordant with recent clinical studies.


Asunto(s)
Sistema Renina-Angiotensina , Deficiencia de Vitamina D , Albuminuria/tratamiento farmacológico , Albuminuria/etiología , Albuminuria/orina , Humanos , Proyectos Piloto , Vitamina D , Deficiencia de Vitamina D/complicaciones , Deficiencia de Vitamina D/tratamiento farmacológico
7.
Semin Dial ; 35(2): 171-180, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34726295

RESUMEN

INTRODUCTION: There are only scarce data regarding the cardiovascular impact of arteriovenous fistula after kidney transplantation depending on fistula flow. METHODS: We performed a single-center, prospective, cohort study including 49 patients with a functional fistula at 1 year from kidney transplantation. Patients were convened for a clinical work-up, a biological analysis, a fistula's Doppler ultrasonography and an echocardiography. Main judgment criterion was comparison of echocardiography parameters between patients with relative (fistula flow >1 L/min and a fistula flow/cardiac output ratio >20%), absolute high-flow fistula (fistula flow >2 L/min) and normal-flow fistula. RESULTS: High-flow fistula frequency was 69%. Significantly higher left ventricular end-diastolic and systolic diameters were observed in this group compared with the normal-flow fistula group (53 ± 6 vs. 48 ± 7 mm; p = 0.04 and 33 ± 6 vs. 28 ± 8 mm; p = 0.02) and between the absolute and relative high-flow fistula subgroups (56 ± 6 vs. 51 ± 6 mm; p = 0.009 and 35 ± 6 vs. 31 ± 5 mm; p = 0.01). The study showed no other significant differences. CONCLUSIONS: This study showed a significantly higher but not pathological left ventricular end-diastolic and systolic diameters values in patients with high-flow fistula compared with patients with normal-flow fistula and between patients with respectively absolute and relative high-flow fistula.


Asunto(s)
Fístula Arteriovenosa , Derivación Arteriovenosa Quirúrgica , Trasplante de Riñón , Fístula Arteriovenosa/diagnóstico por imagen , Fístula Arteriovenosa/etiología , Derivación Arteriovenosa Quirúrgica/efectos adversos , Estudios de Cohortes , Hemodinámica , Humanos , Trasplante de Riñón/efectos adversos , Estudios Prospectivos , Diálisis Renal/efectos adversos
8.
Materials (Basel) ; 14(17)2021 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-34500889

RESUMEN

Photoassisted synthesis is as a highly appealing green procedure for controlled decoration of semiconductor catalysts with co-catalyst nanoparticles, which can be carried out without the concourse of elevated temperatures, external chemical reducing agents or applied bias potential and in a simple slurry reactor. The aim of this study is to evaluate the control that such a photoassisted method can exert on the properties of ruthenium nanoparticles supported on TiO2 by means of the variation of the incident irradiance and hence of the photodeposition rate. For that purpose, different Ru/TiO2 systems with the same metal load have been prepared under varying irradiance and characterized by means of elemental analysis, transmission electron microscopy and X-ray photoelectron spectroscopy. The photocatalytic activity of the so-obtained materials has been evaluated by using the degradation of formic acid in water under UV-A light. Particles with size around or below one nanometer were obtained, depending on the irradiance employed in the synthesis, with narrow size distribution and homogeneous dispersion over the titania support. The relation between neutral and positive oxidation states of ruthenium could also be controlled by the variation of the irradiance. The obtained photocatalytic activities for formic acid oxidation were in all cases higher than that of undecorated titania, with the sample obtained with the lowest irradiation giving rise to the highest oxidation rate. According to the catalysts characterization, photocatalytic activity is influenced by both Ru size and Ru0/Ruδ+ ratio.

9.
Transplantation ; 105(1): 158-169, 2021 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-33009284

RESUMEN

BACKGROUND: Data on coronavirus disease 2019 (COVID-19) in immunocompromised kidney transplant recipients (KTR) remain scanty. Although markers of inflammation, cardiac injury, and coagulopathy have been previously associated with mortality in the general population of patients with COVID-19, their prognostic impact amongst KTR with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection has not been specifically investigated. METHODS: We conducted a cohort study of 49 KTR who presented with COVID-19. Clinical and laboratory risk factors for severe disease and mortality were prospectively collected and analyzed with respect to outcomes. The study participants were divided into 3 groups: (1) mild disease manageable in an outpatient setting (n = 8), (2) nonsevere disease requiring hospitalization (n = 21), and (3) severe disease (n = 20). RESULTS: Gastrointestinal manifestations were common at diagnosis. The 30-day mortality rate in hospitalized patients was 19.5%. Early elevations of C-reactive protein (>100 mg/L) and interleukin-6 (>65 ng/L) followed by increases in high-sensitivity troponin I (>30 ng/L) and D-dimer (>960 ng/mL) were significantly associated with severe disease and mortality. Viral load did not have prognostic significance in our sample, suggesting that outcomes were chiefly driven by a cytokine release syndrome (CRS). CONCLUSIONS: Regular monitoring of CRS biomarkers in KTR with COVID-19 is paramount to improve clinical outcomes.


Asunto(s)
COVID-19/mortalidad , Síndrome de Liberación de Citoquinas/sangre , Trasplante de Riñón/mortalidad , SARS-CoV-2 , Anciano , Biomarcadores/sangre , Proteína C-Reactiva/análisis , COVID-19/sangre , COVID-19/complicaciones , Femenino , Productos de Degradación de Fibrina-Fibrinógeno/análisis , Hospitalización , Humanos , Interleucina-6/sangre , Masculino , Persona de Mediana Edad , Índice de Severidad de la Enfermedad , Troponina I/sangre
10.
ACS Appl Mater Interfaces ; 12(50): 55766-55781, 2020 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-33284584

RESUMEN

Virtually transparent photocatalytic multilayer films composed of TiO2 nanoparticles and polyelectrolytes were built on model surfaces using layer-by-layer assembly and investigated as photocatalytic nanoporous coatings. Formic acid (HCOOH) and Escherichia coli were used as models for the degradation of gaseous pollutants and for studying antibacterial properties. Positively charged TiO2 nanoparticles were coassembled with negatively charged poly(sodium 4-styrenesulfonate) (NaPSS) which leads to highly transparent nanoscale coatings in which the content of TiO2 particles is controlled mainly by the number of deposition cycles and the enhanced translucency with respect to titania powders is likely due to the presence of the polyelectrolytes in the interstitial space between the particles. Build-up and structural properties of the films were determined by ellipsometry, quartz crystal microbalance (QCM-D, with dissipation monitoring), and UV-vis spectrophotometry in transmission and scanning electron microscopy. Complementary photophysical and activity tests of (PSS/TiO2)n multilayer films were performed in the gas-phase under UV-A light and revealed a peculiar dependence on the number of layer pairs (LPs), corresponding to a clear deviation from the usual observations in photocatalysis with increasing TiO2 amounts. Most notably, a single LP film showed a strongly enhanced HCOOH mineralization and outperformed films with a higher number of LPs, with respect to the quantity of TiO2 catalyst present in the films. It is believed that the high quantum yield (8.1%) of a coating consisting of a single TiO2 layer which is 6-7 times higher than that of a 6-10 LP film could be due to the optimum accessibility of the TiO2 crystallites toward both HCOOH and water molecules. In thicker films, while no detrimental light screening was observed with increasing the number of LPs, diffusion phenomena could cap the efficiency of the access of the pollutant and water to the catalytic surface. Unlike for HCOOH mineralization, three PSS/TiO2 LPs were required for observing a maximum antibacterial activity of the nanocomposite coatings. This is likely due to the fact that micrometer-sized E. coli bacteria do not enter into the interstitial space between the TiO2 particles and require a different surface morphology with respect to the number of active contact points for optimum degradation.


Asunto(s)
Antibacterianos/química , Formiatos/química , Nanoporos , Polielectrolitos/química , Titanio/química , Rayos Ultravioleta , Antibacterianos/farmacología , Catálisis , Escherichia coli/efectos de los fármacos , Polímeros/química , Propiedades de Superficie
11.
ACS Appl Mater Interfaces ; 12(51): 57025-57037, 2020 Dec 23.
Artículo en Inglés | MEDLINE | ID: mdl-33296165

RESUMEN

Ti-modified LaFeO3/ß-SiC alveolar foams were used as immobilized, highly robust dual catalysts with combined photocatalytic wet peroxide oxidation and photocatalytic activity under UV-A light. They were prepared by incipient wetness impregnation of a ß-SiC foam support, by implementing a sol-gel Pechini synthesis at the foam surface in the presence of dried amorphous sol-gel titania as a titanium source. The physicochemical and catalytic features suggest the stabilization at the foam surface of a substituted La1-xTixFeO3 catalyst analogous to its powdery counterpart. Taking 4-chlorophenol removal in water as a model reaction, its dual nature enables both high reaction rates and full total organic carbon (TOC) conversion because of a synergy effect, while its macroscopic structure overcomes the drawback of working with powdery catalysts. Further, it yields photonic efficiencies for degradation and mineralization of ca. 9.4 and 38%, respectively, that strongly outperform those obtained with a reference TiO2 P25/ß-SiC foam photocatalyst. The enhancement of the catalyst robustness upon Ti modification prevents any Fe leaching to the solution, and therefore, the optimized macroscopic foam catalyst with 10 wt % catalyst loading operates through pure heterogeneous surface reactions, without any activity loss during reusability test cycles.

12.
Nephrol Dial Transplant ; 35(8): 1338-1411, 2020 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-32871594

RESUMEN

BACKGROUND: There are only scarce data regarding the presentation, incidence, severity and outcomes of coronavirus disease 2019 (COVID-19) in patients undergoing long-term haemodialysis (HD). A prospective observational study was conducted in eight HD facilities in Alsace, France, to identify clinical characteristics of HD patients with COVID-19 and to assess the determinants of the risk of death. METHODS: All HD patients tested positive for COVID-19 from 5 March to 28 April 2020 were included. Collected data included patient characteristics, clinical features at diagnosis, laboratory data, treatments and outcomes. RESULTS: Among 1346 HD patients, 123 tested positive for COVID-19. Patients had a median age of 77 years (interquartile range 66-83), with a high number of comorbidities (3.2 ± 1.6 per patient). Symptoms were compatible in 63% of patients. Asthenia (77%), diarrhoea (34%) and anorexia (32%) were frequent at diagnosis. The delay between the onset of symptoms and diagnosis, death or complete recovery was 2 (0-5), 7 (4-11) and 32 (26.5-35) days, respectively. Treatment, including lopinavir/ritonavir, hydroxychloroquine and corticosteroids, was administered in 23% of patients. The median C-reactive protein (CRP) and lymphocyte count at diagnosis was 55 mg/L (IQR 25-106) and 690 Ly/µL (IQR 450-960), respectively. The case fatality rate was 24% and determinants associated with the risk of death were body temperature {hazard ratio [HR] 1.96 [95% confidence interval (CI) 1.11-3.44]; P = 0.02} and CRP at diagnosis [HR 1.01 (95% CI 1.005-1.017); P < 0.0001]. CONCLUSIONS: HD patients were found to be at high risk of developing COVID-19 and exhibited a high rate of mortality. While patients presented severe forms of the disease, they often displayed atypical symptoms, with the CRP level being highly associated with the risk of death.


Asunto(s)
Betacoronavirus/genética , Proteína C-Reactiva/metabolismo , Infecciones por Coronavirus/epidemiología , ADN Viral/análisis , Fallo Renal Crónico/epidemiología , Neumonía Viral/epidemiología , Diálisis Renal/métodos , Anciano , Anciano de 80 o más Años , Biomarcadores/sangre , COVID-19 , Comorbilidad , Infecciones por Coronavirus/sangre , Femenino , Francia/epidemiología , Humanos , Fallo Renal Crónico/sangre , Fallo Renal Crónico/terapia , Masculino , Pandemias , Neumonía Viral/sangre , Estudios Prospectivos , SARS-CoV-2 , Tasa de Supervivencia/tendencias
13.
J Hazard Mater ; 400: 123099, 2020 12 05.
Artículo en Inglés | MEDLINE | ID: mdl-32569979

RESUMEN

LaFeO3@TiO2 heterojunction composites with a core-shell porous structure and LaFeO3 contents in the 2.5-25 wt.% range have been synthesized via consecutive sol-gel syntheses and tested for the photocatalytic oxidation of the myclobutanil pesticide in water under solar light and pure visible light. Whatever the light spectrum, the kinetic rate constants for both myclobutanil degradation and TOC conversion exhibited a volcano-like profile with increasing the narrow band-gap (2.1 eV) LaFeO3 content, the optimum composite strongly overperforming both single phases, with full myclobutanil mineralization achieved in 240 min in the best case. The light spectrum influenced the optimum LaFeO3 content in the composite, being observed at 5 wt.% and 12.5 wt.% under solar and visible light, respectively. This has been attributed to the existence of different light-mediated reaction mechanisms. The optimum LaFeO3/TiO2 composite photocatalyst was active and stable after several runs under solar light with leached iron concentration below 0.1 mg/L in solution.

15.
J Nanosci Nanotechnol ; 20(9): 5938-5943, 2020 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-32331199

RESUMEN

Viticulture is one of the crops most subject to pest control by fungicides. Their drainage towards the fresh water affects the aquatic environment, the fauna, the flora and especially the human health. It is therefore necessary to find an adequate solution to solve this problem. Heterogeneous photocatalysis is an advanced oxidation method for the degradation and mineralization of organic pollutants in water and air using semi-conductor (e.g., TiO²). TiO2 P25 in suspension (0.75 g·L-1) is used to treat Myclobutanil contaminated water and a commercial formulation Systhane™ 20EW, a fungicide produced by BASF. After 120 min of batch treatment under our conditions (pH = 6.7, Co = 10 mg ·L-1), 96% and 98% of Myclobutanil and Systhane were removed with 94% and 92% mineralization, respectively. In order to avoid the recovery of nanoparticles of TiO² P25 after treatment, we have taken care of ß-SiC foam cells. Under the same experimental conditions, 45% and 56% of Myclobutanil and Systhane degraded after 4 h with mineralization of 29% and 27%, respectively in recirculation in a fixed-light photoreactor by UV-A lamps. These results are very encouraging: filtering is not necessary to separate the catalyst from the treated water, it is very important for large-scale use of this process.

16.
ACS Appl Bio Mater ; 3(9): 5687-5698, 2020 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-35021800

RESUMEN

Photocatalytic antibacterial and biofilm-preventive activity in liquid of heavy-metal-free coatings based on a phosphorus (P)- and fluorine (F)-modified TiO2 photocatalyst has been investigated. They reveal significantly higher immediate and longer-term (biofilm-preventive) inactivation capacity than a reference coating made of the commercial photocatalyst TiO2 P25 on three bacterial species differing in cell wall type and ability to resist oxidative stress (Escherichia coli, Staphylococcus epidermidis, Pseudomonas fluorescens) (up to more than 99% reduction of colonization on P/F-modified TiO2 coating compared to about 50% on P25 TiO2 coating for 10 min UV-A illumination). This results from the P- and F-induced improvement of photocatalyst properties and from the smoother surface topography, which shortens reactive oxygen species (ROS) diffusion to the outer membrane of the targeted adhered bacteria. Decrease in ROS-related impairment of cell wall, respiratory, and enzymatic activities confirms the loss of ROS throughout the bacterial cell degradation. Staphylococcus epidermidis and Pseudomonas fluorescens are less sensitive than Escherichia coli, with a probable relation to the bacterial oxygen stress defense mechanism. The coating antibacterial efficacy was highly affected by phosphate ions and the richness in dissolved oxygen of the reaction medium.

17.
RSC Adv ; 10(7): 3817-3825, 2020 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-35492643

RESUMEN

Coating-free TiO2@ß-SiC photocatalytic composite foams gathered within a ready-to-use shell/core alveolar medium the photocatalytically active TiO2 phase and the ß-SiC foam structure were prepared via a multi-step shape memory synthesis (SMS) replica method. They were fabricated following a sequential two-step carburization approach, in which an external TiC skin was synthesized at the surface of a ß-SiC skeleton foam obtained from a pre-shaped polyurethane foam during a first carburization step. The adsorption behaviour of the shell/core TiO2@ß-SiC composite foams towards the Diuron pollutant in water was tuned by submitting the carbide foams to a final calcination treatment within the 550-700 °C temperature range. The controlled calcination step allowed (i) the selective oxidation of the TiC shell into a TiO2 crystallite shell owing to the ß-SiC resistance to oxidation and (ii) the amount of residual unreacted carbon in the foams to be tuned. The lower the calcination temperature, the more pronounced the adsorption profiles of the composites and the higher the Diuron amount removed by adsorption on the residual unreacted carbon. The ready-to-use TiO2@ß-SiC composite foams were active in the degradation of the Diuron pesticide, without any further post-synthesis immobilization or synthesis process at the foam surface. They displayed good reusability with test cycles and benefitted from an enhanced stability in terms of the titania release to water.

18.
Top Curr Chem (Cham) ; 378(1): 6, 2019 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-31840192

RESUMEN

Ferrites are a large class of oxides containing Fe3+ and at least another metal cation that have been investigated for and applied to a wide variety of fields ranging from mature technologies like circuitry, permanent magnets, magnetic recording and microwave devices to the most recent developments in areas like bioimaging, gas sensing and photocatalysis. In the last respect, although ferrites have been less studied than other types of semiconductors, they present interesting properties such as visible light absorption, tuneable optoelectronic properties and high chemical and photochemical stability. The versatility of their chemical composition and of their crystallographic structure opened a playground for developing new catalysts with enhanced efficiency. This article reviews the recent development of the application of ferrites to photoassisted processes for environmental remediation and for the synthesis of solar fuels. Applications in the photocatalytic degradation of pollutants in water and air, photo-Fenton, and solar fuels production, via photocatalytic and photoelectrochemical water splitting and CO2 reduction, are reviewed paying special attention to the relationships between the physico-chemical characteristics of the ferrite materials and their photoactivated performance.


Asunto(s)
Compuestos Férricos/química , Luz Solar , Contaminantes Atmosféricos/química , Dióxido de Carbono/química , Dióxido de Carbono/metabolismo , Catálisis , Hidrógeno/química , Hidrógeno/metabolismo , Agua/química , Purificación del Agua
19.
Hemodial Int ; 23(4): 426-432, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31380605

RESUMEN

INTRODUCTION: Hemodialysis patients with contraindication to systemic anticoagulation require a heparin-free hemodialysis technique. Among several alternatives to heparin, predilution hemodiafiltration (HDF) is often used, albeit without any confirmation of its effectiveness. METHODS: Patients hospitalized in a nephrology ICU and hemodialysed for stage 5 CKD or AKI and with contraindication to systemic anticoagulation were randomized to either standard HD with a polysulfone membrane, or to predilution HDF with the same membrane. Coagulation activation was evaluated clinically by the need for premature termination and by the measurement of D-dimers. FINDINGS: Two hundred dialysis sessions were performed in 155 patients. Survival curves showed better circuit survival in HD (P = 0.046). In HD, 12% of sessions were interrupted for coagulation versus 23% in predilution HDF (P = 0.04). DISCUSSION: Predilution HDF was associated with more premature clotting than conventional HD without improvement in dialysis duration or performance epuration indices. When aiming for a 4-hour duration session, conventional heparin-free hemodialysis can be safely proposed in most patients with high bleeding risk.


Asunto(s)
Coagulación Sanguínea/efectos de los fármacos , Hemodiafiltración/métodos , Fallo Renal Crónico/sangre , Diálisis Renal/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos
20.
Nephrol Ther ; 15(2): 97-103, 2019 Apr.
Artículo en Francés | MEDLINE | ID: mdl-30827822

RESUMEN

INTRODUCTION: Chronic kidney disease is associated with a high likelihood of receiving cardiovascular drugs. The Haute Autoritéde santé in France still recommends the use of the Cockcroft and Gault formula for dosage adjustments, on the pretext that it is the main data available in the Vidal® drug database. To verify this assumption, we conducted a systematic review of the Vidal® database by looking for the method recommended for evaluating renal function for the purpose of dose adjustment of cardiovascular drugs. METHODS: Vidal® files and SPC of Cardiovascular Drug (ATC classifications B01 and C) were analyzed and classified according to the method of evaluation or measurement of renal function recommended for dose adjustments. RESULTS: A total of 196 molecules were identified, of which 62.6% required dose adjustment to renal function. The most commonly used evaluation method was creatinine clearance (without precision about estimation or measurement) with a frequency of 35.5%. The frequency of use of the Cockcroft and Gault formula was 3.9% (8.4% after review of the literature concerning the molecules stating the clearance of creatinine, as the reference method). CONCLUSION: The privileged use of Cockcroft and Gault formula for dose adjustment, as recommended by the Haute Autoritéde santé, does not seem to be justified. An overhaul of recommendations for pharmacokinetic studies and renal function assessment methods for dose adjustments appears necessary.


Asunto(s)
Fármacos Cardiovasculares/administración & dosificación , Tasa de Filtración Glomerular , Insuficiencia Renal Crónica/sangre , Fármacos Cardiovasculares/farmacocinética , Creatinina/sangre , Creatinina/orina , Relación Dosis-Respuesta a Droga , Francia , Humanos , Conceptos Matemáticos
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