Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Nutrients ; 14(23)2022 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-36501223

RESUMEN

Chronic kidney disease (CKD) represents a frequent comorbidity in cancer patients, especially for patients affected by urological cancers. Unfortunately, impaired kidney function may limit the choice of adequate oncological treatments for their potential nephrotoxicity or due to contraindications in case of a low glomerular filtration rate. For these patients, tailored nephrological and nutritional management is mandatory. The K-DIGO guidelines do not define whether the nutritional management of CKD could be useful also in CKD patients affected by urological cancer. In fact, in clinical practice, oncological patients often receive high-protein diets to avoid malnutrition. In our study, we investigated the nutritional and nephrological impact of a Mediterranean-like diet with a controlled protein intake (MCPD) on a cohort of 82 stage III-IV CKD patients. We compared two cohorts: one of 31 non-oncological CKD patients and the other of 51 oncological patients with CKD. The use of an MCPD had a favorable impact on both the oncological and non-oncological CKD patients with an amelioration in all the investigated parameters and with a better quality of life, with no cases of malnutrition or AKI.


Asunto(s)
Desnutrición , Nefrología , Insuficiencia Renal Crónica , Humanos , Dieta con Restricción de Proteínas , Calidad de Vida , Progresión de la Enfermedad , Insuficiencia Renal Crónica/terapia , Desnutrición/etiología
2.
Beilstein J Org Chem ; 17: 589-621, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33747233

RESUMEN

Metal-catalysed depolymerisation of plastics to reusable building blocks, including monomers, oligomers or added-value chemicals, is an attractive tool for the recycling and valorisation of these materials. The present manuscript shortly reviews the most significant contributions that appeared in the field within the period January 2010-January 2020 describing selective depolymerisation methods of plastics. Achievements are broken down according to the plastic material, namely polyolefins, polyesters, polycarbonates and polyamides. The focus is on recent advancements targeting sustainable and environmentally friendly processes. Biocatalytic or unselective processes, acid-base treatments as well as the production of fuels are not discussed, nor are the methods for the further upgrade of the depolymerisation products.

3.
J Hazard Mater ; 406: 124294, 2021 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-33160788

RESUMEN

The island of Murano (Venice, Italy) is famous worldwide for its artistic glass production. Diarsenic trioxide was a main ingredient of the raw glass mixture until 2015, when the authorisation process of European REACH Regulation (Registration Evaluation Authorisation of Chemicals) entered into force, effectively forbidding the use of arsenic. A total of 3077 PM10 samples were collected across the Venice area in 2013-2017. This period included the REACH Sunset Date (May 2015). High arsenic concentrations were recorded in Murano before the Sunset Date (average 383 ng/m3), representing a serious concern for public health. Other sites in Venice complied with the EU target value. In 2013, concentrations were 36-folds higher than model estimation computed over the maximum-allowed emission scenario. Polar plot analysis indicated Murano as the major source of arsenic contamination. The concentration significantly dropped after the REACH implementation, thus meeting the European target values. However, high peaks of arsenic were still detected; inspections on raw and finished glass materials confirmed that some factories were still using arsenic. Results reported serious airborne arsenic pollution in Murano before the REACH implementation. This work represents an interesting case study on the effectiveness of the European REACH process.

4.
Arch Acad Emerg Med ; 8(1): e84, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33244519

RESUMEN

Splenic injuries after colonoscopy are an uncommon complication, which can lead to potentially unfortunate outcomes. Their management depends on the type of the splenic damage (hematomas, lacerations, rupture). We describe the case of a woman who visited the Emergency Department due to abdominal pain and pre-syncopal condition, which had occurred 12 hours after she underwent a colonoscopy. An abdominal computed tomography scan showed a splenic hematoma and a hemoperitoneum. An emergency splenectomy was performed successfully. Emergency physicians, who are at the forefront of diagnosing and treating patients, should consider this post-endoscopic complication in order to implement a prompt treatment.

5.
Chem Soc Rev ; 49(17): 6329-6363, 2020 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-32749443

RESUMEN

Bisphenol A is an oil-derived, large market volume chemical with a wide spectrum of applications in plastics, adhesives and thermal papers. However, bisphenol A is not considered safe due to its endocrine disrupting properties and reproductive toxicity. Several functional substitutes of bisphenol A have been proposed in the literature, produced from plant biomass. Unless otherwise specified, the present review covers the most significant contributions that appeared in the time span January 2015-August 2019, describing the sustainable catalytic synthesis of rigid diols from biomass derivatives. The focus is thereupon on heterogeneous catalysis, use of green solvents and mild conditions, cascade processes in one-pot, and continuous flow setups. More than 500 up-to-date references describe the various substitutes proposed and the catalytic methods for their manufacture, broken down according to the main biomass types from which they originate.


Asunto(s)
Compuestos de Bencidrilo/química , Biomasa , Tecnología Química Verde , Fenoles/química , Catálisis , Conservación de los Recursos Naturales
6.
Sci Total Environ ; 708: 135217, 2020 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-31810702

RESUMEN

Three biochars were produced using sawdust from waste biomass, via a simple pyrolysis thermal conversion at 450, 650, and 850 °C (BC450, BC650, and BC850), without any activation process. These materials, together with vegetal and mineral commercial activated carbons (VAC and MAC), were characterized for their elemental composition, Brunauer-Emmett-Teller surface area, t-plot microporosity and Barrett-Joyner-Halenda mesoporosity. Moreover, iodine, phenol and methylene blue porosity indexes were measured. The materials were also evaluated for their pH of the point of zero charge, as well as near-surface chemical composition and surface functionality by means of X-ray photoelectron and Fourier-transform infrared spectroscopy. Ash content, water-extractable metals and polycyclic aromatic hydrocarbons (PAHs) were also determined. BC650 showed a much higher surface area (319 m2 g-1) compared to BC450 (102 m2 g-1), as well as an increase in aromatization and the residual presence of functional polar groups. BC850 exhibited a loss of polar and aromatic groups, with the dominance of graphitic carbon and the highest value of surface area (419 m2 g-1). Biochars comply with the EN 12915-1/2009 limits for metal and PAH release in water treatment. Biochars and MAC were tested using Langmuir and Freundlich isotherms for the sorption in real effluent wastewater of a mixture of 14 branched ethoxylated 4-t-octyl and 4-nonylphenols, as well as 4-t-octyl and 4-nonylphenol, the latter representing persistent, endocrine disrupting contaminants, widespread in the effluents from wastewater treatment plants and listed as priority/priority hazardous substances in the Directive 2013/39/EU. Biochars showed a lower sorption efficiency compared to MAC. The best performance was found for BC650 towards the alkylphenols (9-13 times less efficient than the MAC). Considering the lower market price of biochar compared to MAC (estimated as at least 16 times less expensive by a small market survey), the former can be considered more competitive than the latter.


Asunto(s)
Carbón Orgánico , Adsorción , Fenómenos Químicos , Fenoles , Textiles , Aguas Residuales
7.
ChemSusChem ; 12(12): 2558-2563, 2019 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-31050160

RESUMEN

The oxidation reaction of 5-hydroxymethylfurfural to the bioplastic monomer 2,5-furandicarboxylic acid over heterogenous resin-supported Pt catalysts was investigated in detail, under continuous flow, base-free conditions, and in neat water. The product was continuously obtained in 99 % yield by running the reaction at 120 °C, 303 s residence time, 1.2 mL min-1 O2 flow rate, and 7.7 bar O2 pressure. The product was isolated with a high space-time-yield of 46.0 g L-1 h-1 without purifications or acid/base treatments.

8.
Beilstein J Org Chem ; 13: 734-754, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28503209

RESUMEN

The catalytic partial hydrogenation of substituted alkynes to alkenes is a process of high importance in the manufacture of several market chemicals. The present paper shortly reviews the heterogeneous catalytic systems engineered for this reaction under continuous flow and in the liquid phase. The main contributions appeared in the literature from 1997 up to August 2016 are discussed in terms of reactor design. A comparison with batch and industrial processes is provided whenever possible.

9.
Reprod Biomed Online ; 32(2): 154-61, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26655650

RESUMEN

In this retrospective study of 873 men enrolled for assisted reproduction techniques, relationships between sperm quality parameters, motile sperm organelle morphology examination (MSOME), DNA damage and live birth rate were evaluated. The presence of vacuoles in the sperm heads was detected by MSOME. Either chromatin decondensation or DNA fragmentation was used to study DNA damage. Results show that age significantly affected some of the examined parameters. In particular, sperm concentration was positively correlated (R = 0.088; P = 0.01) and chromatin decondensation was negatively correlated (R = -0.102; P = 0.003) with age. Furthermore, live birth rate was significantly lower in men aged 40 years or older (P < 0.02) compared with the younger age groups. The presence of sperm head vacuoles was not associated with head morphology, main sperm quality parameters, DNA fragmentation and live birth rate. Considering sperm heads in relation to the shape (normal/abnormal) and vacuoles (presence/absence), no significant variations in the occurrence of vacuoles in either normal or abnormal heads were found. These data suggest that vacuoles are physiological features that do not alter sperm functionality, and it seems that MSOME is not necessary for increasing the success of assisted reproduction techniques.


Asunto(s)
Infertilidad Masculina/terapia , Reproducción , Técnicas Reproductivas Asistidas , Cabeza del Espermatozoide/fisiología , Espermatozoides/citología , Vacuolas/química , Adulto , Tasa de Natalidad , Cromatina/química , Daño del ADN , Fragmentación del ADN , Humanos , Masculino , Persona de Mediana Edad , Orgánulos/química , Estudios Retrospectivos , Semen , Análisis de Semen/métodos , Motilidad Espermática/fisiología , Adulto Joven
10.
Anal Chem ; 87(13): 6709-17, 2015 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-26020452

RESUMEN

An interlaboratory comparison (ILC) was organized with the aim to set up quality control indicators suitable for multicomponent quantitative analysis by nuclear magnetic resonance (NMR) spectroscopy. A total of 36 NMR data sets (corresponding to 1260 NMR spectra) were produced by 30 participants using 34 NMR spectrometers. The calibration line method was chosen for the quantification of a five-component model mixture. Results show that quantitative NMR is a robust quantification tool and that 26 out of 36 data sets resulted in statistically equivalent calibration lines for all considered NMR signals. The performance of each laboratory was assessed by means of a new performance index (named Qp-score) which is related to the difference between the experimental and the consensus values of the slope of the calibration lines. Laboratories endowed with a Qp-score falling within the suitable acceptability range are qualified to produce NMR spectra that can be considered statistically equivalent in terms of relative intensities of the signals. In addition, the specific response of nuclei to the experimental excitation/relaxation conditions was addressed by means of the parameter named NR. NR is related to the difference between the theoretical and the consensus slopes of the calibration lines and is specific for each signal produced by a well-defined set of acquisition parameters.

11.
Zygote ; 21(4): 330-6, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22398023

RESUMEN

The integrity of sperm chromatin structure has proven to be of great importance for human fertility. In this study, we investigated whether sperm cryopreservation has an effect on nuclear DNA tertiary structure, (i.e. condensation), measured by aniline blue staining, in 103 male patients who required consultation for hypo-fertility. Sperm DNA damage was significantly higher in patients showing oligospermia and severe morphological abnormalities than in native sperm populations. Furthermore we observed that chromatin decondensation was related to the cryostorage technique and to the duration of storage. This increase in decondensation was highly significant (P < 0.01) immediately after cryopreservation and from 90 days of cryostorage onwards. The possible mechanisms involved in sperm chromatin cryoinjury and the need to incorporate new methods for testing sperm nuclear structure alteration into the routine spermiogram are discussed.


Asunto(s)
Cromatina , Criopreservación , Infertilidad Masculina , Preservación de Semen , Espermatozoides/fisiología , Núcleo Celular/genética , Daño del ADN , Humanos , Masculino
12.
Molecules ; 15(6): 3829-56, 2010 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-20657411

RESUMEN

Nanostructured single-site heterogeneous catalysts possess the advantages of classical solid catalysts, in terms of easy recovery and recycling, together with a defined tailored chemical and steric environment around the catalytically active metal site. The use of inorganic oxide supports with selected shape and porosity at a nanometric level may have a relevant impact on the regio- and stereochemistry of the catalytic reaction. Analogously, by choosing the optimal preparation techniques to obtain spatially isolated and well-characterised active sites, it is possible to achieve performances that are comparable to (or, in the most favourable cases, better than) those obtained with homogeneous systems. Such catalysts are therefore particularly suitable for the transformation of highly-functionalised fine chemicals and some relevant examples where high chemo-, regio- and stereoselectivity are crucial will be described.


Asunto(s)
Nanoestructuras/química , Catálisis , Modelos Moleculares , Óxidos/química , Porosidad
13.
Dalton Trans ; 39(36): 8391-402, 2010 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-20390200

RESUMEN

The combination of chiral- and nano-technologies is potentially one of the most promising strategies for "green" catalytic conversions aimed at fine-chemical production. This paper reviews the most representative examples and highlights recent achievements in the field of enantioselective processes catalyzed by metal nanoparticles (MNPs), with a view to the potential of the methodology and future perspectives. Applications are described according to the nanocatalyst type used, either liquid-phase suspensions or solid-supported systems. The focus is on the design of the catalysts, their preparation and characterization, applications in catalysis and mechanistic studies.


Asunto(s)
Nanopartículas del Metal/química , Catálisis , Líquidos Iónicos/química , Magnetismo , Micelas , Nanotubos de Carbono/química , Estereoisomerismo
14.
Chem Rev ; 109(2): 515-29, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19105606
15.
Liver Int ; 29(1): 103-12, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18544126

RESUMEN

BACKGROUND/AIMS: Drugs with antivascular endothelial growth factor A (anti-VEGF-A) action are under clinical evaluation with encouraging results in advanced hepatocellular carcinoma (HCC). The relative VEGF-A protein expression in non-advanced HCC and in the cirrhotic non-tumoral tissue in the same patient, a variable that could be important for treatment efficacy, has been investigated with conflicting results, only using the cirrhotic tissue surrounding the neoplasm (CS). METHODS: We measured, for the first time, VEGF-A expression in non-advanced HCC and in the respective CS and cirrhotic tissue at a distance from the tumour (CD), in 24 patients who underwent liver transplantation. RESULTS: VEGF-A protein was more expressed (P<0.05) in HCC than in CD, while no difference was found between HCC and CS. In HCC patients with a serum alpha-fetoprotein (AFP) higher than 20 ng/ml, VEGF-A protein expression in HCC was higher than in the corresponding CD in 83% of cases and AFP and serum VEGF-A corrected for the platelet count positively correlated with the differential VEGF-A protein expression between HCC and CD. CONCLUSION: Our data provide a rationale for clinical trials involving anti-VEGF-A treatments in patients with non-advanced HCC, and suggest that serum AFP and VEGF-A are variables to be taken into account in these studies.


Asunto(s)
Carcinoma Hepatocelular/sangre , Expresión Génica , Cirrosis Hepática/sangre , Factor A de Crecimiento Endotelial Vascular/sangre , alfa-Fetoproteínas/metabolismo , Western Blotting , Femenino , Humanos , Inmunohistoquímica , Italia , Trasplante de Hígado , Masculino , Persona de Mediana Edad
16.
Obes Surg ; 15(3): 367-77, 2005 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-15826472

RESUMEN

BACKGROUND: The presence of hypercholesterolemia is currently not considered a selection criteria for performing gastric restrictive or diversionary bariatric surgery. METHODS: We prospectively investigated the effects of the bilio-intestinal bypass (BI-bypass) with a wide cholecysto-jejunal anastomosis and of adjustable gastric banding (AGB) on blood lipid concentrations in obese patients. To clarify the mechanism of the hypocholesterolemic effect of the BI-bypass, daily fecal sterol excretion was measured by gas-liquid chromatography (GLC). RESULTS: At 1 year after BI-bypass compared to baseline, the hypercholesterolemic (n=18) and the normocholesterolemic (n=19) patients significantly reduced total (-38% and -27%, respectively), LDL (-47% and -24%, respectively) and HDL (-11% and -13%, respectively) cholesterol and total / HDL cholesterol ratio (-25% and -13%, respectively). At 1 year after AGB, the total / HDL cholesterol ratio was significantly decreased (-11%) compared to baseline in hypercholesterolemic (n=12) but not in normocholesterolemic (n=6) patients, while total and LDL cholesterol were not affected in both groups. At 3 years after BI-bypass compared to baseline, the hypercholesterolemic (n=9) and the normocholesterolemic (n=11) patients significantly reduced total (-43% and -28%, respectively) and LDL (-53% and -29%, respectively) cholesterol and total / HDL cholesterol ratio (-38% and -21%, respectively). The BI-bypass induced a significant (P <0.005; n=7) 6-fold increase in mean fecal cholesterol output. CONCLUSIONS: The BI-bypass but not the AGB leads to a persistent and marked beneficial effect on blood LDL cholesterol associated with an increased cholesterol fecal output. BI-bypass but not AGB is indicated in morbidly obese patients with hypercholesterolemia.


Asunto(s)
Desviación Biliopancreática/métodos , Colesterol/sangre , Derivación Gástrica/métodos , Derivación Yeyunoileal/métodos , Obesidad Mórbida/cirugía , Adulto , Ácidos y Sales Biliares/análisis , Colestanol/análisis , Colesterol/análisis , HDL-Colesterol/sangre , LDL-Colesterol/sangre , Heces/química , Femenino , Estudios de Seguimiento , Humanos , Hipercolesterolemia/sangre , Hipercolesterolemia/terapia , Masculino , Obesidad Mórbida/sangre , Fitosteroles/análisis , Estudios Prospectivos , Triglicéridos/sangre
17.
Liver Transpl ; 11(2): 140-51, 2005 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-15666381

RESUMEN

A total of 44 donor/recipient perioperative and intraoperative variables were prospectively analyzed in 89 deceased-donor liver transplantations classified as initial good graft function (IGGF) or initial poor graft function (IPGF) according to a scoring system based on values obtained during the 1st 72 postoperative hours from the serum alanine aminotransferase (ALT) concentration, bile output, and prothrombin activity. The IGGF compared with the IPGF group showed: 1) longer graft (P = .002) and patient (P = .0004) survival; 2) at univariate analysis, a higher (mean [95% confidence interval]) preharvest donor arterial partial pressure of oxygen (PaO(2)) (152 [136-168] and 104 [91-118] mmHg, respectively; P = .0008) and arterial hemoglobin oxygen saturation (97.9 [97.2-98.7] and 96.7 [95.4-98.0]%, respectively; P = .0096), a lower percentage of donors older than 65 years (13 and 33%, respectively; P = .024), a lower percentage of donors treated with noradrenaline (16 and 41%, respectively; P = .012). At multivariate analysis, IGGF was associated positively with donor PaO(2) and negatively with donor age greater than 65 years and with donor treatment with noradrenaline. Independently from the grouping according to initial graft function, graft survival was longer when donor PaO(2) was >150 mmHg than when donor PaO(2) was < or =150 mmHg (P = .045). In conclusion, preharvest donor hyperoxia predicts IGGF and longer graft survival.


Asunto(s)
Supervivencia de Injerto , Trasplante de Hígado , Oxígeno/sangre , Recolección de Tejidos y Órganos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Alanina Transaminasa/sangre , Análisis de los Gases de la Sangre , Niño , Femenino , Humanos , Masculino , Análisis Multivariante , Valor Predictivo de las Pruebas , Estudios Prospectivos
18.
J Org Chem ; 69(18): 6153-5, 2004 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-15373507

RESUMEN

alpha-O-Linked glycohomoglutamates are obtained as diastereomerically pure compounds by chemo-, regio-, and stereoselective cycloadditions between glycals and aspartic acid derivatives. The latter constitute orthogonally functionalized scaffolds for glycopeptide mimetics.


Asunto(s)
Glicopéptidos/síntesis química , Imitación Molecular , Glicopéptidos/química , Estructura Molecular , Estereoisomerismo
19.
J Org Chem ; 68(22): 8529-33, 2003 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-14575481

RESUMEN

A nonclassical, totally stereoselective synthesis of orthogonally protected 1,3-disaccharides is reported. Enantiomerically pure beta-keto-delta-lactones, efficiently obtained from glucal and galactal, are transformed into electron-poor heterodienes and chemo-, regio-, and stereoselectively cycloadded to glycals as electron-rich dienophiles, to directly afford 2-thiodisaccharides. The reductive desulfurization of the latter smoothly gave the corresponding 2,2'-dideoxydisaccharides.


Asunto(s)
Disacáridos/síntesis química , Galactosa/análogos & derivados , Gluconato de Calcio/química , Secuencia de Carbohidratos , Cromomicina A3/química , Ciclización , Galactosa/química , Cetonas/química , Lactonas/química , Datos de Secuencia Molecular , Piranos/química , Quinonas/química , Estereoisomerismo , Compuestos de Sulfhidrilo/química
20.
Biochem J ; 365(Pt 3): 833-40, 2002 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-11952428

RESUMEN

Analysis of the genome structure of the Paracentrotus lividus (sea urchin) DNA methyltransferase (DNA MTase) gene showed the presence of an open reading frame, named METEX, in intron 7 of the gene. METEX expression is developmentally regulated, showing no correlation with DNA MTase expression. In fact, DNA MTase transcripts are present at high concentrations in the early developmental stages, while METEX is expressed at late stages of development. Two METEX cDNA clones (Met1 and Met2) that are different in the 3' end have been isolated in a cDNA library screening. The putative translated protein from Met2 cDNA clone showed similarity with Escherichia coli endonuclease III on the basis of sequence and predictive three-dimensional structure. The protein, overexpressed in E. coli and purified, had functional properties similar to the endonuclease specific for apurinic/apyrimidinic (AP) sites on the basis of the lyase activity. Therefore the open reading frame, present in intron 7 of the P. lividus DNA MTase gene, codes for a functional AP endonuclease designated SuAP1.


Asunto(s)
Endonucleasas/metabolismo , Intrones/genética , Metiltransferasas/metabolismo , Sistemas de Lectura Abierta/genética , Erizos de Mar/enzimología , Erizos de Mar/genética , Secuencia de Aminoácidos , Animales , ADN/metabolismo , Embrión no Mamífero/anatomía & histología , Embrión no Mamífero/fisiología , Regulación del Desarrollo de la Expresión Génica , Humanos , Hibridación in Situ , Masculino , Metiltransferasas/clasificación , Modelos Moleculares , Datos de Secuencia Molecular , Filogenia , Estructura Terciaria de Proteína , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Erizos de Mar/embriología , Alineación de Secuencia
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...