Structure-Property Correlation of Hierarchically Porous Carbons for Fluorocarbon Adsorption.

Although traditional commercially available porous carbon-fluorocarbon working pairs have shown promising applicability for adsorption cooling, advancements in engineered carbons may further improve the performance. Moreover, insights into structure-property relationships that target higher sorption capacities within these synthesized carbons may guide such materials' future design. We utilized hierarchically porous carbons (HPCs), synthesized with colossal microporous and mesoporous content characterized by high surface areas (up to 2689 m2/g) and pore volume values (up to 10.31 cm3/g) toward fluorocarbon R134a adsorption. This unique pore topology leads to exceptional R134a uptake, ∼250 wt %, outperforming the highest uptake carbon material to date, Maxsorb III (∼220 wt %). Material characterizations reveal that the outstanding R134a capacity may be attributed to textural properties and oxygen-terminated functional groups more than graphitization of the material. Most importantly, HPCs are efficiently utilized in a two-bed model chiller device, where the performance shows excellent working capacity (105 wt %, ∼2 times the value of reported carbon materials/R134a). Fluorocarbon adsorption on HPCs also displays fast kinetics (equilibrium time: ∼2 min) mainly driven by physical adsorption (Qst: ∼27 kJ/mol), characteristic of swiftly reversible behavior adsorption-desorption behaviors. This work provides a fundamental understanding of the applicability of HPCs/R134a working pair for adsorption cooling.

Hierarchically Porous Graphitic Carbon with Simultaneously High Surface Area and Colossal Pore Volume Engineered via Ice Templating.

Developing hierarchical porous carbon (HPC) materials with competing textural characteristics such as surface area and pore volume in one material is difficult to accomplish, particularly for an atomically ordered graphitic carbon. Herein we describe a synthesis strategy to engineer tunable HPC materials across micro-, meso-, and macroporous length scales, allowing the fabrication of a graphitic HPC material (HPC-G) with both very high surface area (>2500 m2/g) and pore volume (>11 cm3/g), the combination of which has not been attained previously. The mesopore volume alone for these materials is up to 7.53 cm3/g, the highest ever reported, higher than even any porous carbon's total pore volume, which for our HPC-G material was >11 cm3/g. This HPC-G material was explored for use both as a supercapacitor electrode and for oil adsorption, two applications that require either high surface area or large pore volume, textural properties that are typically exclusive to one another. We accomplished these high textural characteristics by employing ice templating not only as a route for macroporous formation but as a synergistic vehicle that enabled the significant loading of the mesoporous hard template. This design scheme for HPC-G materials can be utilized in broad applications, including electrochemical systems such as batteries and supercapacitors, sorbents, and catalyst supports, particularly supports where a high degree of thermal stability is required.

Pore-Engineered Metal-Organic Frameworks with Excellent Adsorption of Water and Fluorocarbon Refrigerant for Cooling Applications.

Metal-organic frameworks (MOFs) have shown promising behavior for adsorption cooling applications. Using organic ligands with 1, 2, and 3 phenylene rings, we construct moisture-stable Ni-MOF-74 members with adjustable pore apertures, which exhibit excellent sorption capabilities toward water and fluorocarbon R134a. To our knowledge, this is the first report of adsorption isotherms of fluorocarbon R134a in MOFs. The adsorption patterns for these materials differ significantly and are attributed to variances in their hydrophobic/hydrophilic pore character associated with differences in pore size.

Self-Assembled Fe-N-Doped Carbon Nanotube Aerogels with Single-Atom Catalyst Feature as High-Efficiency Oxygen Reduction Electrocatalysts.

Self-assembled M-N-doped carbon nanotube aerogels with single-atom catalyst feature are for the first time reported through one-step hydrothermal route and subsequent facile annealing treatment. By taking advantage of the porous nanostructures, 1D nanotubes as well as single-atom catalyst feature, the resultant Fe-N-doped carbon nanotube aerogels exhibit excellent oxygen reduction reaction electrocatalytic performance even better than commercial Pt/C in alkaline solution.

Analysis of the components of a cognitive-behavioral intervention administered via conference call for preventing depression among non-professional caregivers: a pilot study.

OBJECTIVES: The primary aim was to assess the feasibility/acceptability of a preventive cognitive-behavioral intervention implemented via conference call for caregivers. The secondary aim was to conduct a preliminary assessment of the efficacy of the behavioral activation component alone compared to the complete cognitive-behavioral intervention. METHOD: Sixty-one caregivers (mean age 58.4 years) were randomly assigned to a cognitive-behavioral intervention via conference call (CBC, n = 20), a behavioral activation intervention via conference call (BAC, n = 22) or a control group receiving usual care (CG, n = 19). Both interventions consisted of five 90-minute group sessions implemented weekly. RESULTS: Only 6.6% of caregivers discontinued the study. In the CBC and BAC groups, attendance and satisfaction with the intervention were similarly high among both groups. Homework adherence was also high in both groups. At post-treatment, there was a lower incidence of depression in the CBC and BAC groups compared to the CG (0.0% for BAC and CBC vs. 10.5% for CG). The relative risk was 0.0, and number needed to treat was 10 in both groups. Depressive symptoms were significantly reduced in the CBC and BAC groups compared to the CG (d = 2.18 and d = 2.06). CONCLUSION: The results support the feasibility of the intervention. Moreover, the BAC intervention was non-inferior to the CBC intervention for reducing depressive symptoms.

Tunable Oxygen Functional Groups as Electrocatalysts on Graphite Felt Surfaces for All-Vanadium Flow Batteries.

A dual oxidative approach using O2 plasma followed by treatment with H2 O2 to impart oxygen functional groups onto the surface of a graphite felt electrode. When used as electrodes for an all-vanadium redox flow battery (VRB) system, the energy efficiency of the cell is enhanced by 8.2 % at a current density of 150 mA cm(-2) compared with one oxidized by thermal treatment in air. More importantly, by varying the oxidative techniques, the amount and type of oxygen groups was tailored and their effects were elucidated. It was found that O-C=O groups improve the cells performance whereas the C-O and C=O groups degrade it. The reason for the increased performance was found to be a reduction in the cell overpotential after functionalization of the graphite felt electrode. This work reveals a route for functionalizing carbon electrodes to improve the performance of VRB cells. This approach can lower the cost of VRB cells and pave the way for more commercially viable stationary energy storage systems that can be used for intermittent renewable energy storage.

3D Conducting Polymer Platforms for Electrical Control of Protein Conformation and Cellular Functions.

We report the fabrication of three dimensional (3D) macroporous scaffolds made from poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) via an ice-templating method. The scaffolds offer tunable pore size and morphology, and are electrochemically active. When a potential is applied to the scaffolds, reversible changes take place in their electrical doping state, which in turn enables precise control over the conformation of adsorbed proteins (e.g., fibronectin). Additionally, the scaffolds support the growth of mouse fibroblasts (3T3-L1) for 7 days, and are able to electrically control cell adhesion and pro-angiogenic capability. These 3D matrix-mimicking platforms offer precise control of protein conformation and major cell functions, over large volumes and long cell culture times. As such, they represent a new tool for biological research with many potential applications in bioelectronics, tissue engineering, and regenerative medicine.

Synthesis and carbon dioxide sorption of layered double hydroxide/silica foam nanocomposites with hierarchical mesostructure.

Layered double hydroxides (LDHs) with a hierarchical mesostructure are successfully synthesized on mesoporous silica foams by simple impregnation and hydrothermal treatment. The as-synthesized LDH/silica foam nanocomposites show well-defined mesostructures with high surface areas, large pore volumes, and mesopores of 6-7 nm. The nanocomposites act as carbon dioxide (CO2 ) sorbents under simulated flue gas conditions. They also exhibit significantly enhanced CO2 capacities under high-pressure conditions and high CO2 /N2 and CO2 /CH4 selectivities.

Deposition of LDH on plasma treated polylactic acid to reduce water permeability.

A simple and scalable deposition process was developed to prepare polylactic acid (PLA) coatings with enhanced water barrier properties for food packaging applications. This method based on electrostatic interactions between the positively charged layers of layered double hydroxides (LDHs) modified with ionic liquids (ILs) and the negatively charged plasma treated polylactic acid leads to homogeneous, stable, and highly durable coatings. Deposition of the LDH coatings increases the surface hydrophobicity of the neat PLA, which results to a decrease in water permeability by about 35%.

Synthesis and physical properties of new layered double hydroxides based on ionic liquids: application to a polylactide matrix.

Ionic liquids based on tetraalkylphosphonium salts combined with different anions (decanoate and dodecylsulfonate) have been used as intercalating agents of layered double hydroxides (LDHs) by ion exchange. The synthesized phosphonium-treated LDHs display a dramatically improved thermal degradation and a significant increase in the interlayer distance as confirmed by thermogravimetric analysis (TGA) and X-ray Diffraction (XRD), respectively. To highlight the effect of thermostable ionic liquids, a very low amount of LDHs has been introduced within a polylactide (PLA) matrix and PLA/LDHs nanocomposites have been processed in melt by twin-screw extrusion. Then, transmission electron microscopy (TEM) analysis has been used to investigate the influence of ILs on the different morphologies of these nanocomposites. Even though the thermal stability of PLA matrix decreased, an excellent stiffness-toughness compromise has been obtained.

Multifunctional graphene/platinum/Nafion hybrids via ice templating.

We report the synthesis of multifunctional hybrids in both films and bulk form, combining electrical and ionic conductivity with porosity and catalytic activity. The hybrids are synthesized by a two-step process: (a) ice templation of an aqueous suspension comprised of Nafion, graphite oxide, and chloroplatinic acid to form a microcellular porous network and (b) mild reduction in hydrazine or monosodium citrate which leads to graphene-supported Pt nanoparticles on a Nafion scaffold.

Estrategia de intervención educativa en salud bucal para gestantes / Strategy for educative intervention in oral health for the pregnant

Se realizó una investigación en Servicios de Salud de tipo descriptivo en el período comprendido de abril a octubre de 2001, con el objetivo de elaborar una estrategia de intervención educativa para la promoción de salud y la prevención de enfermedades bucales durante el embarazo, tomamos como referencia un trabajo precedente donde se determinaron las necesidades educativas en las 55 embarazadas ingresadas en los cuatro hogares maternos del municipio Camagüey. Una vez realizado el diagnóstico educativo e identificados los principales problemas de salud bucal asociados al embarazo se construyó una matriz DAFO que posibilitó identificar las fuerzas internas del sector de la salud (fortalezas y debilidades) y las fuerzas externas al sector (oportunidades y amenazas) para lo cual se hizo uso del criterio de expertos. Con el análisis de la misma se determinaron los objetivos para la estrategia, así como el problema estratégico a través de la elaboración de un plan de acción y se propuso un sistema de evaluación con respecto a la estrategia de intervención educativa para la promoción y prevención de la salud bucal en las gestantes

[Clinical research in urology and scientific methodology]. / Investigación clínica en urología y metodología científica.

Clinical epidemiology is the science and method of studying the optimal decisions in clinical medicine, taking into consideration the epidemiological characteristics of the patient and his/her external clinical environment, the disease involved, and factors and procedures to which the patient is exposed in his/her clinical environment, specially clinical actions. Research should be a systematic process, organized and objective, aimed to answer the question posed. Systematic means that the scientific method is applied, for that a hypothesis or work objective is formulated from observations or established knowledge about a topic, data are collected following a pre-established design, and, once analyzed and interpreted, conclusions are obtained which will modify or add new knowledge to the previous, and a new cycle starts again. Organization means that all members in the research team know perfectly what to do during the whole study, apply the same definitions and criteria to all participants, and act in identical way in front of any doubt. To achieve this, it is mandatory to write a protocol specifying all details related to the study. The meaning of the word objective is that conclusions obtained are not based on subjective impressions but on facts that have been observed, measured, and analyzed, and that any prejudice the study responsibles could have is avoided during its interpretation.

[Ipsilateral metanephric adenoma and clear-cell carcinoma. Personal experience and review of the literature]. / Adenoma metanéfrico y carcinoma de células claras ipsilaterales. Experiencia personal y revisión de la literatura.

OBJECTIVES: To perform an update in such an infrequent pathology and to report our own experience. METHODS: We report two new cases and review the national and international literature. RESULTS: We report two cases of ipsilateral metanephric adenoma and clear cell carcinoma. The first case, metachronous, was detected after 15 months of follow-up in a patient who underwent partial nephrectomy due to clear cell carcinoma. The second one, synchronic, was incidentally discovered in the surgical specimen. CONCLUSIONS: Metanephric adenoma is as infrequent neoplasia; its diagnosis is histological, being difficult to suspect by complementary diagnostic tests, so that most cases undergo surgical treatment in spite of its benign character.

[Influence of recipient age on renal transplantation performed with organs coming from child donors]. / Influencia de la edad del receptor en el trasplante renal realizado con órganos procedentes de donantes infantiles.

OBJECTIVES: To evaluate the influence of receptor's age on the outcomes of kidney transplants with organs from donors below the age of three years and/or weighting less than 15 Kg. METHODS: We retrospectively studied the renal transplants with organs from donors below the age of three years and/or weighting less than 15 Kg performed at the Hospital Clínico San Carlos between 1991 and 1999. Receptors were divided into two groups depending on the age at the time of transplantation; group I included patients younger than 50 years and group II patients older than 50. RESULTS: We study 49 kidney transplants with pediatric donors (8.6%); 22 of them were included in group I and 27 in group II. There were no deaths among receptors younger than 50 years. Five-year survival for group II was 75.99%. Five-year graft survival what's 81.82% for group I, and 88.89% for group II (p 0.45). CONCLUSIONS: Receptor's age does not seem to influence graft survival when this kind of organs are used; we consider that the lower incidence of acute rejection in patients older than 50 years may explain the excellent response.

[Effect of recipient age on transplants performed using organs from donors in asystole]. / Influencia de la edad del receptor en el trasplante realizado con órganos procedentes de donantes en asistolia.

OBJECTIVES: To evaluate the influence of receptor's age on the outcomes of kidney transplants with organs from non heart beating donors. METHODS: Observational study of the historic cohort of 570 kidney transplants performed at the Hospital Clínico San Carlos between 1991 and 1999. Receptor's were divided into two age groups, group 1 younger than 50 years, and group 2 older than 50 years. All organs where harvested from non heart beating donors. RESULTS: We studied 110 kidney transplants coming from non heart beating donors; 52 belonged to group 1, and 57 to group 2. Three-year patient survival for receptor's younger than 50 years was 100%. The probability of three-year survival for receptor's older than 50 years was 79.39% (p 0.07). Graft survival was 88.46%, 86.54%, and 86.54% at 12, 24, and 36 months respectively for receptor's younger than 50 years. When receptors were older than 50 years the probability of functioning graft in the same periods of time was 89.20%, 89.20%, and 86.32% respectively. CONCLUSIONS: Receptor's age doesn't seem to influence graft survival when kidneys from non heart beating donors are used.

[Renal transplantation in donors over 60 years of age]. / Trasplante renal en receptores mayores de 60 años.

OBJECTIVES: To evaluate the impact of receptor's advanced age on kidney transplant outcomes. METHODS: We reviewed all transplants performed between January 1990 and December 1999. Among 570 patients receiving grafts, 115 patients were 60 years or older at the time of transplantation. We compared this group with receptors younger than 60 years. We studied possible prognostic variables and compared patient and graft outcomes. RESULTS: Mean age 63.81 (typical deviation (TD): 2.96). Mean follow-up time for elderly receptors was 41.6 months (TD: 26.58). 55.7% patients were males (p: 0.4). The most frequent cause for end stage renal disease was unknown etiology in group 1 and glomerular in the younger group (p: 0.01). 42% patients older than 60 years presented initial graft dysfunction, in comparison to 28.1% among younger than 60 (p: 0.006). Three-year graft survival was 90.42% for receptors 60 years old or older compared to 88.72% for group 2, without significant differences (p: 0.5). The most frequent graft loss etiology was patient death. (67.7%). (p = 0.005). Patient survival was 81.01% in group 1 and 95.25% in group 2, being differences significant (p < 0.001). CONCLUSIONS: Renal grafts in receptors over the age of 60 years show a greater incidence of delayed graft function, although it doesn't seem to influence final graft survival. The most frequent cause for graft loss is receptor's death. Receptor's age does not represent a contraindication for transplant.