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1.
Beilstein J Org Chem ; 18: 1203-1209, 2022.
Article in English | MEDLINE | ID: mdl-36158176

ABSTRACT

Herein, we present the bottom-up, mechanochemical synthesis of phosphorus-bridged heptazine-based carbon nitrides (g-h-PCN). The structure of these materials was determined through a combination of powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), 31P magic angle spinning nuclear magnetic resonance (MAS NMR), density functional theory (DFT) and electron energy loss spectroscopy (EELS). Compared to traditional furnace-based techniques, the presented method utilizes milder conditions, as well as shorter reaction times. Both samples of g-h-PCN directly after milling and aging and after an hour of annealing at 300 °C (g-h-PCN300) show a reduction in photoluminescent recombination, as well as a nearly two-time increase in photocurrent under broad spectrum irradiation, which are appealing properties for photocatalysis.

2.
Mol Divers ; 21(3): 697-711, 2017 08.
Article in English | MEDLINE | ID: mdl-28656524

ABSTRACT

American trypanosomiasis or Chagas disease caused by the protozoan Trypanosoma cruzi (T. cruzi) is an important endemic trypanosomiasis in Central and South America. This disease was considered to be a priority in the global plan to combat neglected tropical diseases, 2008-2015, which indicates that there is an urgent need to develop more effective drugs. The development of new chemotherapeutic agents against Chagas disease can be related to an important biochemical feature of T. cruzi: its redox defense system. This system is based on trypanothione ([Formula: see text],[Formula: see text]-bis(glutathyonil)spermidine) and trypanothione reductase (TR), which are rather unique to trypanosomes and completely absent in mammalian cells. In this regard, tricyclic compounds have been studied extensively due to their ability to inhibit the T. cruzi TR. However, synthetic derivatives of natural products, such as [Formula: see text]-carboline derivatives ([Formula: see text]-CDs), as potential TR inhibitors, has received little attention. This study presents an analysis of the structural and physicochemical properties of commercially available [Formula: see text]-CDs in relation to compounds tested against T. cruzi in previously reported enzymatic assays and shows that [Formula: see text]-CDs cover chemical space that has not been considered for the design of TR inhibitors. Moreover, this study presents a ligand-based approach to discover potential TR inhibitors among commercially available [Formula: see text]-CDs, which could lead to the generation of promising [Formula: see text]-CD candidates.


Subject(s)
Carbolines/chemistry , Enzyme Inhibitors/chemistry , NADH, NADPH Oxidoreductases/antagonists & inhibitors , Trypanocidal Agents/chemistry , Trypanosoma cruzi/enzymology , Carbolines/pharmacology , Computer Simulation , Databases, Pharmaceutical , Drug Evaluation, Preclinical , Enzyme Inhibitors/pharmacology , Glutathione/analogs & derivatives , Glutathione/chemistry , Models, Molecular , Molecular Docking Simulation , Molecular Structure , NADH, NADPH Oxidoreductases/chemistry , Spermidine/analogs & derivatives , Spermidine/chemistry , Trypanocidal Agents/pharmacology , Trypanosoma cruzi/drug effects
3.
J Environ Manage ; 158: 1-10, 2015 Aug 01.
Article in English | MEDLINE | ID: mdl-25932562

ABSTRACT

The catalytic hydrodechlorination (HDC) of high concentrations of trichloroethylene (TCE) (4.9 mol%, 11.6 vol%) was studied over 1%Pd, 1%Rh and 0.5%Pd-0.5%Rh catalysts supported on CeO2 under conditions of room temperature and pressure. For this, a one-phase system of NaOH/2-propanol/methanol/water was designed with molar percentages of 13.2/17.5/36.9/27.6, respectively. In this system, the alcohols delivered the hydrogen required for the reaction through in-situ dehydrogenation reactions. PdRh/CeO2 was the most active catalyst for the degradation of TCE among the evaluated materials, degrading 85% of the trichloroethylene, with alcohol dehydrogenation rates of 89% for 2-propanol and 83% for methanol after 1 h of reaction. Fresh and used catalysts were characterized by Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS), and Thermogravimetric analysis (TGA). These results showed important differences of the active phase in each catalyst sample. Rh/CeO2 had particle sizes smaller than 1 nm and the active metal was partially oxidized (Rh(0)/Rh(+δ) ratio of 0.43). This configuration showed to be suitable for alcohols dehydrogenation. On the contrary, Pd/CeO2 showed a Pd completed oxidized and with a mean particle size of 1.7 nm, which seemed to be unfavorable for both, alcohols dehydrogenation and TCE HDC. On PdRh/CeO2, active metals presented a mean particle size of 2.7 nm and more reduced metallic species, with ratios of Rh(0)/Rh(+δ) = 0.67 and Pd(0)/Pd(+δ) = 0.28, which showed to be suitable features for the TCE HDC. On the other hand, TGA results suggested some deposition of NaCl residues over the catalyst surfaces. Thus, the new reaction system using PdRh/CeO2 allowed for the degradation of high concentrations of the chlorinated compound by using in situ hydrogen liquid donors in a reaction at room temperature and pressure.


Subject(s)
Palladium/chemistry , Rhenium/chemistry , Trichloroethylene/chemistry , Water Pollutants, Chemical/chemistry , Catalysis , Cerium/chemistry , Humans , Methanol/chemistry , Sodium Hydroxide/chemistry , Water/chemistry , Water Purification/methods
4.
J Clin Med ; 12(12)2023 Jun 09.
Article in English | MEDLINE | ID: mdl-37373645

ABSTRACT

Portal vein thrombosis was considered a contraindication for liver transplantation. This study analyzes the perioperative complications and survival of liver transplant patients with portal vein thrombosis (PVT). A retrospective observational cohort study of liver transplant patients was conducted. The outcomes were early mortality (30 days) and patient survival. A total of 201 liver transplant patients were identified and 34 (17%) patients with PVT were found. The most frequent extension of thrombosis was Yerdel 1 (58.8%), and a portosystemic shunt was identified in 23 (68%) patients. Eleven patients (33%) presented any early vascular complication, PVT being the most frequent (12%). The multivariate regression analysis showed a statistically significant association between PVT and early complications (OR = 3.3, 95% confidence interval 1.4-7.7; p = 0.006). Moreover, early mortality was observed in eight patients (24%), of which two (5.9%) presented Yerdel 2. For Yerdel 1, patient survival according to the extent of thrombosis was 75% at 1 year and 3 years, while for Yerdel 2, it was 65% at 1 year, and 50% at 3 years (p = 0.04). Portal vein thrombosis significantly influenced early vascular complications. Furthermore, portal vein thrombosis Yerdel 2 or higher impacts the survival of liver grafts in the short and long term.

5.
ChemSusChem ; 15(21): e202201535, 2022 Nov 08.
Article in English | MEDLINE | ID: mdl-36121437

ABSTRACT

The design of functionalized metallic nanoparticles is considered an emerging technique to ensure the interaction between metal and semiconductor material. In the literature, this interface interaction is mainly governed by electrostatic or van der Waals forces, limiting the injection of electrons under light irradiation. To enhance the transfer of electrons between two compounds, close contact or chemical bonding at the interface is required. Herein, a new approach was reported for the synthesis of chemically bonded plasmonic Au NPs/ZIF-67 nanocomposites. The structure of ZIF-67 was grown on the surface of functionalized plasmonic Au NPs using 1H-1,2,4-triazole-3-thiol as the capping agent, which acted as both stabilizer of Au nanoparticles and a molecular linker for ZIF-67 formation. As a result, the synthesized material exhibited outstanding photocatalytic CO2 reduction with a methanol production rate of 2.70 mmol h-1 g-1 cat under sunlight irradiation. This work emphasizes that the diligent use of capping agents, with suitable functional groups, could facilitate the formation of intimate heterostructure for enhanced photocatalytic CO2 reduction.

6.
Chemosphere ; 303(Pt 1): 134861, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35584713

ABSTRACT

The use of tetracycline hydrochloride (TCH) for veterinary, human therapy, and agriculture has risen in the past few decades, making it to become one of the most exploited antibiotics. However, TCH residue in the environment is causing issues related to the evolution of antibiotic-resistant bacteria. To address such a problem, photodegradation offers a potential solution to decompose these pollutants in wastewater and thereby mitigates negative environmental impacts. In this context, the research focuses on the use of the rare-earth metal oxide samarium orthovanadate (SmVO4) with nanorod structure, coupled with UiO-66-NH2 for the photocatalytic degradation. Their photocatalytic activity to degrade antibiotic TCH molecules is explored under simulated solar light irradiation. The integration of UiO-66-NH2 with SmVO4 enhanced the light absorption, recombination resistance, carrier lifetime (from 0.382 to 0.411 ns) and specific surface area (from 67.17 to 246 m2/g) of the composite system as confirmed from multiple analyses. The obtained results further indicated that SmVO4/UiO-66-NH2 nanocomposites could form a direct Z-scheme based heterojunction. Such mechanism of charge transfer leads to the effective degradation of TCH molecules up to 50% in 90 min under solar light, while it is degraded only 30% in the case of bare-SmVO4 nanorods. In this work, the incorporation of UiO-66-NH2 positively influences photoelectrochemical properties and improves the overall photoredox properties of SmVO4 for the degradation of complex compounds like antibiotic TCH molecules. Therefore, UiO-66-NH2 can be proposed as an effective material to sensitize the rare-earth based photocatalytic material.


Subject(s)
Nanocomposites , Tetracycline , Anti-Bacterial Agents , Catalysis , Humans , Metal-Organic Frameworks , Nanocomposites/chemistry , Phthalic Acids , Sunlight
7.
Article in English | MEDLINE | ID: mdl-34207880

ABSTRACT

The sorption behavior of 2,4-dichlorophenoxyacetic acid (2,4-D) in the abundant agricultural volcanic ash-derived soils (VADS) is not well understood despite being widely used throughout the world, causing effects to the environment and human health. The environmental behavior and risk assessment of groundwater pollution by pesticides can be evaluated through kinetic models. This study evaluated the sorption kinetics and 2,4-D sorption-desorption in ten VADS through batch sorption experiments. Differences in the sorption extent for the fast and slow phases was observed through the IPD model where 2,4-D sorption kinetics was controlled by external mass transfer and intra organic matter diffusion in Andisols (C1 ≠ 0). We confirmed from the spectroscopic analysis that the carboxylate group directly drives the interaction of 2,4-D on Andisol soil. The MLR model showed that IEP, FeDCB, and pH×Silt are important soil descriptors in the 2,4-D sorption in VADS. The Freundlich model accurately represented sorption equilibrium data in all cases (Kf values between 1.1 and 24.1 µg1-1/n mL1/ng-1) with comparatively higher sorption capacity on Andisols, where the highest hysteresis was observed in soils that presented the highest and lowest OC content (H close to 0).


Subject(s)
Herbicides , Soil Pollutants , 2,4-Dichlorophenoxyacetic Acid , Adsorption , Herbicides/analysis , Humans , Kinetics , Soil , Soil Pollutants/analysis
8.
ACS Med Chem Lett ; 11(10): 1913-1918, 2020 Oct 08.
Article in English | MEDLINE | ID: mdl-33062173

ABSTRACT

The small molecule gibberellin JRA-003 was identified as an inhibitor of the NF-kB (nuclear kappa-light-chain-enhancer of activated B cells) pathway. Here we find that JRA-003 binds to and significantly inhibits the nuclear translocation of pathway-activating kinases IKKα (IκB kinase alpha) and IKKß (IκB kinase beta). Analogs of JRA-003 were synthesized and NF-κB-inhibiting gibberellins were found to be cytotoxic in cancer-derived cell lines (HS 578T, HCC 1599, RC-K8, Sud-HL4, CA 46, and NCIH 4466). Not only was JRA-003 identified as the most potent synthetic gibberellin against cancer-derived cell lines, it displayed no cytotoxicity in cells derived from noncancerous sources (HEK 293T, HS 578BST, HS 888Lu, HS 895Sk, HUVEC). This selectivity suggests a promising approach for the development of new therapeutics.

9.
J Hazard Mater ; 385: 121576, 2020 03 05.
Article in English | MEDLINE | ID: mdl-31812478

ABSTRACT

Nicosulfuron sorption/desorption kinetics were studied through batch sorption studies in ten volcanic ash-derived Andisol and Ultisol soils with acidic pH and variable surface charge. Two different kinetic models were used to fit the experimental data: i) Models to establish kinetic parameters (Pseudo-First and Pseudo-Second-Order), and ii) Models to describe solute transport mechanisms of organic compounds on sorbents (Intraparticle Diffusion, Dimensionless Intraparticle, Boyd, and Two-Site Nonequilibrium). Sorption kinetic data best fit the pseudo-second-order model. Application of these models to describe solute transport suggests that underlying mechanisms are complex in all soils due to: i) surface sorption, with mass transfers controlling sorption kinetics across the boundary layer; and ii) pore diffusion (i.e. intraparticle diffusion into macropores and micropores). The Freundlich model explained equilibrium sorption data in all cases (R2 > 0.9979) with Kf values higher than those reported for different class of soils (6.85-16.08 µg1-1/n mL1/n  g-1). The hysteresis was significant in all studied soils. The lower sorption rate on Ultisols must be considered in regards to Nicosulfuron leaching potential.

10.
J Hazard Mater ; 379: 120746, 2019 11 05.
Article in English | MEDLINE | ID: mdl-31276919

ABSTRACT

Glyphosate is used extensively worldwide, but current evidence suggests detrimental effects on the environment, pollinators, and human health. Glyphosate adsorption kinetics and adsorption/desorption were studied through batch sorption experiments in ten typical volcanic ash-derived soils from Andisol and Ultisol orders. Two kinetic models were used to fit the experimental data: i. Models that allowed establishment of principally kinetic parameters and modeling of the adsorption process, and ii. Models described solute transport mechanisms commonly used for remediation purposes. Adsorption kinetic data were best fitted by the pseudo-second-order kinetic model and Two-Site Nonequilibrium model. These models suggest that mechanisms are complex due to rapid surface adsorption in ultisols with mass transfer controlling adsorption kinetics across the boundary layer, as indicated by the highhand lowt1/2values. High intraparticle diffusion into macropores and micropores was observed for Andisols. The Freundlich model accurately represented adsorption equilibrium data in all cases (R2 > 0.9580) with comparatively higher adsorption capacity on Andisols. Kf values (2.50-52.28 µg1-1/n mL1/n g-1) and hysteresis were significant in all studied soils. Taken together, these data suggest that Glyphosate may be adsorbed more on Andisol soils in comparison to Ultisols.

11.
Article in Spanish | LILACS, BINACIS | ID: biblio-1427217

ABSTRACT

Introducción: La sarcopenia está revistiendo importancia en el estudio de diferentes enfermedades para predecir la morbimortalidad en el perioperatorio. Los objetivos de este estudio fueron evaluar la eficacia de la tomografía y la resonancia en la medición de la musculatura del psoas y los paraespinales, y comparar estos índices con la edad, el sexo y la enfermedad. materiales y métodos: Se utilizaron las tomografías computarizadas y las resonancias magnéticas de pacientes ambulatorios. La medición de los músculos se realizó en los pedículos de L3 y L4. Resultados: El estudio incluyó 18 tomografías y 34 resonancias. El rango de edad de los pacientes era de 15 a 80 años, divididos en grupos etarios. En los promedios globales, en ambos estudios, el sexo masculino estaba por encima del promedio global. Con respecto a los rangos etarios, se observó que el primer grupo (15-29 años) tenía un mayor volumen muscular y de unidades Hounsfield en el psoas comparado con el grupo >60 años. Los pacientes que consultaron por espondilolistesis tenían menos masa muscular que aquellos con discopatías. Conclusiones: No existe diferencia entre la resonancia magnética y la tomografía computarizada en cuanto a la medición de los músculos paraespinales y psoas. Queda en evidencia que la disminución del volumen muscular es común en pacientes de mayor edad y con enfermedades que afectan el balance espinal. Nivel de Evidencia: IV


background: Sarcopenia is becoming increasingly significant in the research of various diseases to predict morbidity and mortal-ity in the perioperative period. Objectives: The objectives of this study were to evaluate the efficacy of computed tomography and magnetic resonance imaging in measuring the psoas and paraspinal muscles and to compare these indexes with age, sex, and pathology. materials and methods: Computed tomography and magnetic resonance imaging of outpatients were used. Muscle measurements were taken at the L3 and L4 pedicles. Results: The study included 18 CT and 34 MRI scans. The patients were divided into groups based on their age range, which was 15 to 80 years. In the overall averages, males were above the global average in both studies. Regarding age ranges, it was observed that the first group (15-29 years) had a higher muscle volume and Hounsfield units in the psoas compared to the >60 age group. Patients consulting for spondylolisthesis had less muscle mass than those with discopathy. Conclusions: There is no difference between magnetic resonance imaging and computed tomography in measuring the paraspinal and psoas muscles. It is evident that the decrease in muscle volume is common in older patients and those with diseases that affect spinal balance. Level of Evidence: IV


Subject(s)
Adolescent , Adult , Middle Aged , Aged , Spinal Diseases , Magnetic Resonance Imaging , Tomography, X-Ray Computed , Psoas Muscles , Sarcopenia , Perioperative Period , Paraspinal Muscles
12.
Article in Spanish | LILACS, BINACIS | ID: biblio-1437493

ABSTRACT

Introducción: La enfermedad degenerativa de la columna lumbar es frecuente, pero aún existen dudas en relación con los criterios de inestabilidad. Objetivos: Analizar la relación del signo del fluido facetario lumbar como criterio de inestabilidad vertebral segmentaria. materiales y métodos: Pacientes con enfermedad lumbar crónica, que presentan hidrartrosis facetaria en la resonancia magnética y las radiografías de columna lumbar dinámicas. Se analizan la prevalencia del sexo, la edad, la sintomatología principal y el dolor a la extensión unilateral o bilateral. Resultados: Se evaluó a 139 pacientes (62% mujeres), con un promedio de edad de 50.8 años; el principal motivo de consulta fue lumbalgia (76%). El 65% refería dolor en extensión; el 35%, dolor unilateral y el 30%, dolor bilateral. El 14% tenía espondilolistesis de bajo grado en L4-L5 y el 7%, en L5-S1. La hidrartrosis era unilateral en el 20% y bilateral en el 80%; el nivel de hidrartrosis más frecuente era en L4-L5 (58%). El 6% tenía solo inestabilidad traslacionaly el 2%, mixta. Un 8% presentaba Modic I y un 5%, Modic II. Conclusiones: La presencia de fluido facetario no es un criterio de inestabilidad vertebral segmentaria, al margen del nivel y el segmento localizado, o la presentación facetaria lumbar unilateral o bilateral. Nivel de Evidencia: IV


Introduction: Degenerative lumbar spine disease is prevalent, however, the criteria for instability are still debated. Objectives:To analyze the presence of the lumbar facet fluid sign as a criterion for segmental instability of the spine. materials and meth-ods: Patients with chronic lumbar disease, who present facet hydrarthrosis on MRI and dynamic lumbar spine radiographs. The prevalence of sex, age, main symptomatology, and pain on unilateral or bilateral extension was investigated. Results: A total of 139 patients (62% women) were evaluated, with an average age of 50.8 years; the main reason for consultation was low back pain (76%). Sixty-five percent reported pain in extension, with 35% reporting unilateral pain and 30% reporting bilateral pain. Fourteen percent had low-grade spondylolisthesis at L4-L5 and 7% at L5-S1. Hydrarthrosis was unilateral in 20% and bilateral in 80%; the most frequent level of hydrarthrosis was L4-L5 (58%). Six percent had only translational instability and 2% had mixed instability. 8% and 5%, respectively, had Modic I and Modic II changes. Conclusions: The presence of facet fluid is not a criterion for segmental instability of the spine, regardless of the level and localized segment, or the unilateral or bilateral lumbar facet presentation. Level of Evidence: IV


Subject(s)
Spine , Low Back Pain , Joint Instability , Lumbar Vertebrae
13.
Biomedica ; 26 Suppl 1: 95-108, 2006 Oct.
Article in Spanish | MEDLINE | ID: mdl-17361846

ABSTRACT

INTRODUCTION: Between 2003 and 2004 the largest epidemic of cutaneous leishmaniasis in Colombia (2,810 cases, with the highest incidence of 6,202 x 100,000 in 2004) occurred in the sub-Andean rural area of the municipalities of Chaparral and San Antonio in the department of Tolima. OBJECTIVE: The present study was carried out to identify suspected vectors and to establish the knowledge that the inhabitants have about sand flies in order to use this information for vector control. MATERIALS AND METHODS: 46 houses were sampled with CDC light traps set up indoors to establish the sand fly species composition, abundance and the percentage of infestation. Houses were examined during daylight to identify endophagy. A questionnaire was applied in order to estimate the knowledge about sand flies, their role in transmission and the sites and seasons of highest abundance. RESULTS: Three anthropophilic sand fly species of possible epidemiological importance were found. L. longiflocosa was the dominant sand fly species accounting for 81.7% (192 / 235) of all catches and infested the highest number of houses (41.7%). The other two species were L. columbiana and L. nuneztovari, with relative abundances of 3.4% and 2.1%, respectively, and house infestations of 13.0% and 6.5%, respectively. There was no evidence of endophilic behavior. Inhabitants recognized sand flies and their role in transmission. They identified the houses and the dry season as the site and time period of highest sand fly abundance. CONCLUSIONS: Based on its high anthropophily, predominance and apparent endophagic behavior, L. longiflocosa is the most probable vector of leishmaniasis indoors. L. columbiana and L. nuneztovari could be involved as secondary vectors outdoors. The importance of these findings on sand fly control is discussed.


Subject(s)
Health Knowledge, Attitudes, Practice , Insect Vectors/parasitology , Leishmaniasis, Cutaneous/transmission , Psychodidae/parasitology , Animals , Colombia , Humans , Leishmaniasis, Cutaneous/prevention & control , Surveys and Questionnaires
14.
Rev. colomb. cir ; 37(1): 96-105, 20211217. fig, tab
Article in Spanish | LILACS | ID: biblio-1357579

ABSTRACT

Introducción. La resección quirúrgica es el tratamiento de elección de las neoplasias primarias y secundarias del hígado. Los pacientes con hepatocarcinoma de los segmentos centrales representan un reto, siendo la hepatectomía extendida la técnica más usada, sin embargo, el riesgo postquirúrgico de falla hepática es alto, dado que la resección puede comprometer entre el 65 % y el 80 % del volumen hepático. La mesohepatectomía es una alternativa que permite dejar un volumen hepático residual suficiente. El objetivo de este trabajo es presentar nuestra experiencia en el tratamiento de pacientes con hepatocarcinomas en segmentos centrales a quienes se les realizó mesohepatectomía. Serie de casos. Se presentan tres pacientes no cirróticos, con hepatocarcinoma en los segmentos 4, 5 y 8, que fueron atendidos en el Hospital San Vicente Fundación, en las sedes de Medellín y de Rionegro, entre 2018 y 2020. Resultados. La mesohepatectomía se realizó mediante ligadura selectiva de los pedículos del segmento 4 y del sector anterior derecho. Se utilizó aspirador ultrasónico y endograpadora para la transección hepática. La duración de la maniobra de Pringle varió entre 16 y 43 minutos. El sangrado promedio fue de 1000 ml. Solo un paciente presentó fuga biliar tipo B. No hubo mortalidad a 30 días. Conclusiones. La mesohepatectomía es una alternativa segura para pacientes con tumores en los segmentos centrales, que permite disminuir el riesgo de falla hepática luego de la resección.


Introduction. Surgical resection is the treatment of choice for primary and secondary neoplasms of the liver. Patients with central segment hepatocarcinoma represent a challenge, with extended hepatectomy being the most widely used technique. However, the postsurgical risk of liver failure is high since resection can compromise between 65% and 80% of liver volume. Mesohepatectomy is an alternative that allows a sufficient residual liver volume to be left. The objective of this work is to present treatment of patients with central segment hepatocarcinoma.Clinical cases. Three non-cirrhotic patients are presented, with hepatocarcinoma in segments 4, 5 and 8, who were treated at the San Vicente Fundación Hospital in Medellín and Rionegro, between 2018 and 2020.Results. Mesohepatectomy was performed by selective ligation of the pedicles of segment 4 and the right anterior sector. An ultrasonic aspirator and endostapler were used for liver transection. The duration of the Pringle ma-neuver ranged from 16 to 43 minutes. The average bleeding was 1000 cc. Only one patient had type B bile leakage. There was no 30-day mortality.Conclusions. Mesohepatectomy is a safe alternative for patients with tumors in the central segments, which reduces the risk of liver failure after resection.


Subject(s)
Humans , Liver Failure , Carcinoma, Hepatocellular , Liver Cirrhosis , Hepatectomy
15.
J Hazard Mater ; 261: 602-13, 2013 Oct 15.
Article in English | MEDLINE | ID: mdl-23995557

ABSTRACT

Diuron sorption kinetic was studied in Andisols, Inceptisol and Ultisols soils in view of their distinctive physical and chemical properties: acidic pH and variable surface charge. Two types of kinetic models were used to fit the experimental dates: those that allow to establish principal kinetic parameters and modeling of sorption process (pseudo-first-order, pseudo-second-order), and some ones frequently used to describe solute transport mechanisms of organic compounds on different sorbents intended for remediation purposes (Elovich equation, intraparticle diffusion, Boyd, and two-site nonequilibrium models). The best fit was obtained with the pseudo-second-order model. The rate constant and the initial rate constant values obtained through this model demonstrated the behavior of Diuron in each soil, in Andisols were observed the highest values for both parameters. The application of the models to describe solute transport mechanisms allowed establishing that in all soils the mass transfer controls the sorption kinetic across the boundary layer and intraparticle diffusion into macropores and micropores. The slowest sorption rate was observed on Ultisols, behavior which must be taken into account when the leaching potential of Diuron is considered.


Subject(s)
Diuron/chemistry , Herbicides/chemistry , Models, Theoretical , Soil Pollutants/chemistry , Adsorption , Kinetics , Volcanic Eruptions
16.
Article in English | MEDLINE | ID: mdl-21470905

ABSTRACT

Cyclic voltammetry and electron spin resonance techniques were used in the investigation of several potential antiprotozoal containing thiosemicarbazone and carbamate nitrofurans. In the electrochemical behaviour, a self-protonation process involving the nitro group was observed. The reactivity of the nitro anion radical for these derivatives with glutathione, a biological relevant thiol, was also studied in means of cyclic voltammetry. These studies demonstrated that glutathione could react with radical species from 5-nitrofuryl system. Furthermore, from the voltammetric results, some parameters of biological significance as E(7)(1) (indicative of the biological nitro anion radical formation), and [Formula: see text] (thermodynamic indicator the of oxygen redox cycling) have been calculated. We also evaluated the stability of the nitro anion radical in terms of the dimerization constant (k(d)). The nitrofuran-free radicals from cyclic voltammetry were characterized by electron spin resonance. A clear dependence between both the thiosemicarbazone or carbamate substructure and the length of the linker, furyl- or furylpropenyl-spacer, and the delocalization of the unpaired electron was observed. Through of biological assays we obtained important parameters that account for the selective anti-trypanosomal activity of these derivatives. The trypomastigote viability study showed that all derivatives are as active as in the epimastigote form of the parasite in a doses dependent manner.


Subject(s)
Antiprotozoal Agents/chemistry , Antiprotozoal Agents/pharmacology , Nitrofurans/chemistry , Nitrofurans/pharmacology , Trypanosoma cruzi/drug effects , Animals , Cell Line , Cell Survival , Chagas Disease/drug therapy , Electrochemical Techniques , Electron Spin Resonance Spectroscopy , Glutathione/chemistry , Humans , Mice , Thiosemicarbazones/chemistry , Thiosemicarbazones/pharmacology , Trypanosoma cruzi/growth & development
17.
Mol Ecol Resour ; 8(4): 851-3, 2008 Jul.
Article in English | MEDLINE | ID: mdl-21585910

ABSTRACT

We present 10 microsatellite markers for the buttonwood mangrove, Conocarpus erectus, a wide-range mangrove associate species. Polymorphism was assessed among individuals from six different populations along the Pacific Coast of Mexico and Costa Rica, as well as in two individuals from the Yucatan Peninsula in the Atlantic. The number of alleles detected in the Pacific ranged from two to five. All loci amplified in the Yucatan samples and seven loci revealed a unique Atlantic allele. These markers will be useful for studies in the conservation of the species and to study the basic biology of C. erectus.

18.
Rev. biol. trop ; 60(supl.1): 89-97, Mar. 2012. graf, mapas, tab
Article in Spanish | LILACS, SaludCR | ID: lil-657856

ABSTRACT

Abundance and distribution of Strombus gigas (Mesogastropoda: Strombidae) larvae during their reproductive period in the Mexican Caribbean. The Queen Conch (Strombus gigas Linnaeus, 1758) is a species of economic importance in the Caribbean Sea, which, in the 1980’s represented the second fishery after de spiny lobster, reason that is currently in a state of overfishing. In order to determine the larval abundance variation during the reproductive season, four locations of the Mexican Caribbean “MC” (Mexico: Puerto Morelos, Sian Ka’an, Mahahual; Belize: San Pedro) were sampled. Monthly, from May to October 2008, planktonic net drags (300μm) were carried out at each location. Temperature (°C), salinity (ppm) and dissolved oxygen (mg L-1) were recorded for each site. A mean larval density of 0.34±0.87 (larvae 10 m-3) was registered between locations, with a peak in August and September (0.82±1.00 and 0.76±1.68 larvae 10m-3, respectively). The larval density was 60% correlated with salinity (r=0.6063, p<0.05). A one-way ANOVA showed significant statistical larval density in time (p<0.05) and space (p<0.05), where Puerto Morelos displayed the higher records during the study (0.54±1.49 larvae 10m-3). An average larval size of 332.44±59.66µm was recorded. Larval sizes differed significantly between locations (p<0.05), but not considering months (p>0.05). A 100% of the captured larvae correspond to stage I, showing local reproductive activity, that might indicate the sampled sites in the MC are a source of larvae to S. gigas. Rev. Biol. Trop. 60 (Suppl. 1): 89-97. Epub 2012 March 01.


El caracol rosa (Strombus gigas, Linnaeus, 1758) es una especie de importancia económica en el Mar Caribe, por lo cual, en la década de 1980 representó la segunda pesquería después de la langosta espinosa, razón por la que actualmente se encuentra en estado de sobrepesca. Con el objetivo de determinar la variación en la abundancia de larvas durante la época reproductiva, cuatro localidades del Caribe Mexicano “CM” (México: Puerto Morelos, Sian Ka’an, Mahahual; Belice: San Pedro) fueron muestreadas. Mensualmente, de mayo a octubre del 2008, se realizaron arrastres de plancton en cada localidad empleando una red cónica (300μm). Temperatura (°C), salinidad (ppm) y oxígeno disuelto (mg L-1) fueron registrados para cada sitio. Una densidad media larval de 0.34±0.87 larvas•10m-3 fue registrada entre localidades, con un pico de abundancia entre agosto y septiembre (0.82±1.00 y 0.76±1.68 larvas 10m-3, respectivamente). La densidad larval tuvo una correlación del 60% con la salinidad (r=0.6063, p<0.05). El ANOVA de una vía mostró significancia estadística en tiempo (p<0.05) y espacio (p<0.05), donde Puerto Morelos tuvo los mayores registros durante el estudio (0.54±1.49 larvas 10m-3). Fue registrada una talla media de 332.44±59.66µm. Las tallas variaron significativamente entre localidades (p<0.05), pero no entre meses (p>0.05). El 100% de las larvas capturadas corresponden al estadio I definido por Davis et al (1993), mostrando actividad reproductiva local, de esta manera, se considera que los sitios muestreados en el CM son fuente de larvas para la especie S. gigas.


Subject(s)
Snails/anatomy & histology , Reproduction , Mexico
19.
Rev. méd. hondur ; 74(4): 209-217, oct.-dic. 2006. tab
Article in Spanish | LILACS | ID: lil-476367

ABSTRACT

El presente artículo es producto de una cuidadosa revisión de la patogénesis, incidencia, tratamiento y pronostico del Lupus Eritematoso Sistémico (LES) en la mujer embarazada. Debido a su alta prevalencia en el sexo femenino y sobre todo en la edad reproductiva, puede complicar el embarazo ocasionando aborto, muerte fetal, preeclampsia, Retardo del Crecimiento Intrauterino (RCIU) y parto prematuro cuando se asocia a enfermedad activa al momento de la concepción. Así mismo el LES puede exacerbarse en el 30 % de los casos. Se ha observado un aumento en la incidencia del LES en las cuatro últimas décadas y el 15% de los pacientes con esta enfermedad presentaran otra enfermedad autoinmune adyacente. Existen un sinnúmero de terapias para el manejo del LES desde los esteroides, análogos de las purinas y terapias experimentales que pueden ser utilizadas durante el embarazo las cuales mejoran el pronóstico tanto materno como fetal. El manejo de la paciente embarazada portadora de LES debe ser realizado por un equipo médico multidisciplinario e idealmente tener un control médico adecuado seis meses previo a la concepción...


Subject(s)
Female , Pregnancy , Pregnancy Complications/mortality , Lupus Erythematosus, Systemic/complications , Fetal Growth Retardation/mortality , Autoimmune Diseases , Lupus Nephritis/classification
20.
Rev. méd. hondur ; 73(4): 179-183, oct.-dic. 2005.
Article in Spanish | LILACS | ID: lil-444192

ABSTRACT

Muchas de las pacientes con pérdidas fetales anteparto a veces calificadas como pérdida de causa desconocida tienen como antecedentes, trombosis venosa o arterial, plaquetopenias inexplicables, retardo del crecimiento intrauterino(RCIU), infartos placentarios u otras pérdidas fetales previas. Estas pacientes son portadoras del Síndrome de anticuerpos antifosfolípidos (SAFF), cuya fisiopatología completa aún está en estudio. Se considera que el 2% de la población obstétrica es portadora de SAFF. El manejo de la paciente embarazada portadora del SAFF debe ser multidisciplinario, idealmente debe realizarse valoración, manejo y consejería preconcepcional...


Subject(s)
Adult , Humans , Female , Pregnancy , Pregnancy Complications , Antiphospholipid Syndrome/diagnosis , Antiphospholipid Syndrome/prevention & control , Autoimmune Diseases , Prenatal Care
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