Effect of cholesterol on the hydration properties of ester and ether lipid membrane interphases.

Fluorescence spectroscopy and Molecular Dynamics results show that cholesterol reduces water along the chains in ether lipids by changing the water distribution pattern between tightly and loosely bound water molecules. Water distribution was followed by emission spectra and generalized polarization of 6-dodecanoyl-2-dimethyl aminonaphthalene (Laurdan) inserted in 1,2-dimiristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-di-O-tetradecyl-sn-glycero-3-phosphocholine (14: 0 Diether PC) membranes. Molecular Dynamics simulations indicate that the action of cholesterol could be different in ether PC in comparison to ester PC. In addition, Cholesterol seems to act "per se" as an additional hydration center in ether lipids. Regardless of the phase state, cholesterol both in DMPC and 14:0 Diether PC vesicles, changed the distribution of water molecules decreasing the dipole relaxation of the lipid interphase generating an increase in the non-relaxable population. Above 10% Cholesterol/14:0 Diether PC ratio vesicles' interphase present an environment around Laurdan molecules similar to that corresponding to ester PC.

Modulation of Interfacial Hydration by Carbonyl Groups in Lipid Membranes.

The lack of carbonyl groups and the presence of ether bonds give the lipid interphase a different water organization around the phosphate groups that affects the compressibility and electrical properties of lipid membranes. Generalized polarization of 1,2-di-O-tetradecyl-sn-glycero-3-phosphocholine (14:0 diether PC) in correlation with Fourier transform infrared (FTIR) analysis indicates a higher level of polarizability of water molecules in the membrane phase around the phosphate groups both below and above Tm. This reorganization of water promotes a different response in compressibility and dipole moment of the interphase, which is related to different H bonding of water molecules with phosphates (PO) and carbonyl (CO) groups.

Sliding of drops on mesoporous thin films.

There is great interest in developing surfaces with enhanced properties for the sliding of liquid droplets. Here we show that both water and oil droplets placed on mesoporous thin film surfaces slide at relatively small tilt angles with respect to non-porous surfaces of the same material. The effect arises from a particular soft pinning at the contact line, which is a consequence of the fact that sessile droplets are partially "floating" onto a locally self-imbibed mesoporous film. Therefore, droplets present a reduced sliding angle and an enhanced sliding velocity in comparison to droplets on non-porous surfaces of the same material. The formed droplet-substrate interface is different to those observed on superhydrophobic or oil-infused surfaces, and involves a particular sliding dynamic. These findings would help to improve technical developments that require the precise handling of droplet mobility, whose interest span from chemical and biological assays in open microfluidic platforms to applications in energy and the environment.

Electrical current nanogeneration driven by spontaneous nanofluidic oscillations.

Exploiting natural phenomena is a central route for providing electricity to sustainably drive wearable electronics. Here we report a nano-scale water-driven energy generator that produces tiny electrical currents from spontaneous wetting-drying oscillations in mesoporous thin films. The system was fabricated with a wormlike mesoporous silica film, which was packed in between Cu and silicon contacts. The nanogenerator runs autonomously when a water droplet is laid over the film close to the Cu electrode, as water infiltration into the film under the electrode produces a direct-current. Wetting-drying cycles, which are spontaneously triggered by water evaporation, are perfectly correlated to the generated electrical current. The autonomous water displacement through the film yields a sustained energy conversion until the droplet reservoir vanishes. This novel water-driven nanogenerator opens new alternatives for versatile, mobile and cost-effective self-powering of nanosystems and nanodevices.

Embarazo en pacientes con lesión medular / Pregnancy in patients with spinal cord injury

ANTECEDENTES: Las gestaciones en pacientes con daño medular representan un reto para la obstetricia. Las complicaciones más frecuentes son las infecciones de las vías respiratorias y de las vías urinarias, y la más grave la hiperreflexia autonómica. El parto vaginal es posible en lesiones por debajo de T5, pero por encima de ese nivel, la imposibilidad de percibir las contracciones, de identificar el trabajo de parto y realizar pujos lleva a la necesidad de una cesárea programada. OBJETIVO: Exponer nuestra experiencia y revisar el manejo más adecuado de la embarazada parapléjica. MÉTODOS: Estudio retrospectivo en el periodo 2003-2014. Hubo 10 pacientes con 24 gestaciones: 6 abortos espontáneos, un 1 aborto inducido, quedando para el análisis 17 gestaciones (1 embarazo gemelar). La evaluación es independiente a la etiología o localización de la lesión. Se analiza las complicaciones perinatales y maternas. Resultados: La edad media fue 33 años. La edad gestacional media al parto fue 37 semanas: 12 de término (70,59%), 4 de pretérmino (23,53%) y una desconocida (5,88%). Hubo 10 cesáreas (58,82%) y 7 partos vaginales (41,18%). Peso medio neonatal de 2940 g, ninguno con retraso de crecimiento intrauterino. CONCLUSIONES: Nuestra experiencia muestra una alta tasa de prematuridad y de cesáreas, pero con buenos resultados maternos y perinatales, que hace permisible que estas pacientes puedan cumplir su deseo genésico, superando su discapacidad.

BACKGROUND: The pregnancies in patients with spinal cord injury represent a challenge for obstetrics. The most common complications are infections of the respiratory and urinary tract, and the most severe is the autonomic hyperreflexia. Vaginal delivery is possible in lesions below T5, but above that level the inability to perceive contractions, to identify labor and perform straining leads to the need for a scheduled cesarean. OBJECTIVE: To describe our experience and review the most appropriate management of paraplegic pregnant. Methods: Retrospective study in the period 2003-2014. There were 10 patients with 24 pregnancies: 6 spontaneous abortions, 1 induced abortion, leaving 17 for analysis pregnancies (one twin pregnancy). The evaluation is independent of the etiology or location of the lesion. Perinatal and maternal complications were analyzed. RESULTS: The mean age was 33 years. The mean gestational age at delivery was 37 weeks: 12 to term (70.59%), 4 preterm deliveries (23.53%) and one unknow. There were 10 cesarean sections (58.82%) and 7 vaginal deliveries (41.18%). Average birth weight of 2940 g, none with intrauterine growth restriction. CONCLUSIONS: Our experience shows a high rate of prematurity and cesarean section, but with good maternal and perinatal outcomes, which makes it permissible for these patients can fulfill their procreative desire, overcoming his disability.

Evaluation of the risk of transmission of Trichinella in pork production systems in Argentina.

Recently, there has been interest in programs that certify pork production practices that minimize the risk of exposure of pigs to Trichinella spiralis. Certification might be useful for reducing the risk of human trichinellosis from pork in Argentina, but more information is needed on pig production practices and sources of Trichinella infection in Argentinian pigs. In this study, 21 pig farms were assessed for Trichinella infection including some farms using total and partial confinement management, and others with pigs raised exclusively outdoors. A total of 3224 muscle samples were collected from pigs raised on these farms and tested to determine the presence of T. spiralis larvae by artificial digestion. Serum samples from the same 3224 pigs were tested for antibodies to T. spiralis by ELISA. For each farm, a questionnaire was completed summarizing information about management factors and this information was used to assess risk factors for exposure of T. spiralis. Based on the results, pigs raised outdoors were more likely to be infected than pigs raised in total or partial confinement (p< or =0.05). Pigs fed waste products containing meat were 12.5 times more likely to be infected than pigs not fed waste containing meat (p<0.01). The role played by rats in transmission of Trichinella is unclear; however, on farms with evidence of wild animals and access of pigs to wildlife carcasses, the prevalence of Trichinella infection was significantly higher. All pigs raised under good hygienic and sanitary conditions were negative for Trichinella infection by both artificial digestion and ELISA.

Evaluation of the poly-L-lactic acid implant for treatment of the nasolabial fold: 3-year follow-up evaluation.

The search for an ideal filler for soft tissue augmentation still continues. Because aging changes are continuous, temporary fillers should be preferred against permanent ones. Since 1999, the poly-L-lactic acid filler (PLA) has been marketed in Europe as Newfill. As a synthetic biocompatible polymer, PLA originally was used in suture materials and screws. In 2004, the U.S. Food and Drug Administration approved PLA under the name of Sculptra for the treatment of human immunodeficiency virus-related facial lipoatrophy. This study aimed to evaluate a 3-year follow-up investigation into the effect of PLA implant injection for the treatment of sunken nasolabial folds. Between October 2003 and February 2004, 10 women with a median age of 54 years (range, 43-60 years) were injected with polylactic acid hydrogel (Newfill) in the nasolabial fold area for aesthetic reasons. All the patients underwent three injections: one injection per month for 3 months. Evaluation of the results based on clinical examination and photography was performed at each session, at 6 months, and then 36 months after the third session. Injectable PLA was able to correct nasolabial folds successfully with a more lasting result than absorbable fillers commonly used in clinical practice, such as hyaluronic acid and collagen. Careful and standardized photographic documentation is indispensable.

A Web-based distance education course in nutrition in public health: case study.

BACKGROUND: Strict work timetables, personal and professional duties or an inability to be absent from home or work can all represent major constraints for those wishing to improve their professional skills. Within this context, the World Wide Web can allow people to conveniently follow distance courses from their homes. OBJECTIVE: To present an experience in the use of the Web in the continuing education of healthcare professionals in Brazil. METHODS: A Web-based distance education course in nutrition in public health was developed. The methodology was an adaptation of both problem-based and task-based learning. At the end of the course an evaluation questionnaire which covered the course s contents, the educational methodology and resources, the duration and schedule, and the use of the Web as a tool for distance education was given to the students. RESULTS: There were 83 on line registrations from 13 states, 73 of the applicants were female, 62 had a degree in nutrition and 18 were physicians. From these; eleven students from ten states were chosen: nine female nutritionists, two female physicians, and one male physician. Seven students completed the course, took and passed the final exam. Of the other four students, two failed to follow the schedule, one had health problems, and one did not obtain the minimal score for sitting the final exam. The students had a mean age of 35, and a mean of ten years in practice. They all stated that they were unable to attend a regular course, even though they felt that they needed to improve their professional skills. Most of them studied seven days a week for between two and four hours a day. The students also felt that their professional skills had improved and each reported having made changes in their practice as a result of their participation. The students approved of the course s contents, methodology and resources, however they were divided about its duration. The Web as a tool in distance education was approved by the students. If it was not for the Web they could not have taken part in a continuing education program. All students said they would attend another virtual course, if available. Even though most of them did not have difficulty adapting to the virtual environment, they did feel that an adaptation period would be of value. CONCLUSIONS: A Web-based course may be more effective than other distance education methodologies because it is more interactive and dynamic. On-line material can be constantly reviewed and updated, and the students can have the opportunity to submit commentaries or questions directly to the teaching staff. A Web-based course also allows the students to go beyond the course content as they learn how to search and take advantage of the huge resources of information available on the Internet.

[Control of hydatidosis in the Province of Rio Negro, Argentina: epidemiology]. / Control de la hidatidosis en la Provincia de Río Negro, Argentina: epidemiología.

In this paper we attempt to present a general view of the situation of hydatidosis in the Province of Rio Negro, Argentina, considering the magnitude of infection in man and dog. Because of its seriousness a 10 year program for the control of hydatidosis has been carried out, which included veterinary and medical care. The number of human cases with hydatidosis in the period 1981-1988 was determined by a retrospective study of the registers of Public Health. From 1188 cases registered in the period, the annual numbers varied between 152 in 1981 and 104 in 1988. This implies an incidence rate of 40 x 100,000. The most frequent localization observed was in the liver. The average days of hospitalization has decreased to 15.8 per patient. Screening seroepidemiological surveys using DD5 allowed us to determine that the prevalence rate was in some departments of 2330 x 100,000. Also included are the results, up to now, of 10 years of field work done in the program area.