Bayesian analysis of triple Langmuir probe measurements for the characterization of Hall thruster plasmas.

We developed a new experimental approach to characterize the plasma behavior inside Hall thrusters. The main novelty of the developed approach regards the combination of a triple Langmuir probe, which guarantees a high flexibility, and Bayesian data analysis. The triple Langmuir probe was mounted on an articulated arm that can rapidly insert the probe inside the thruster channel, providing a clear picture of relevant plasma properties along the channel centerline, from the near plume to the near-anode region. At a given operating condition of the thruster, multiple measurements were performed, changing the arrangements of the triple probe electrodes and the applied potential differences between the electrodes. Then, in order to analyze the data gathered by the triple probe, a Bayesian integrated data analysis has been adopted. This method made it possible to combine measurements from different electrode arrangements and to improve the quality of the inferred plasma parameters. Non-uniformities of the plasma sensed by the probe electrodes were taken into account within the physical model of particle collection. In order to model the interaction of the electrodes with the plasma, a parametrization of the Laframboise sheath solution was used. The developed diagnostic system, together with the integrated data analysis, proved to be a valid approach to characterize the plasma flow in Hall thrusters, offering not only a good spatial resolution of the electron temperature, plasma density, and space potential but also a consistent estimate of the measurement accuracy.

Epidemiologic and Evolutionary Profile of Patients With Subarachnoid Hemorrhage With Glasgow Coma Scale Score of 8 or Less Who Entered the Follow-Up Program of the National Institute of Donation and Transplantation.

INTRODUCTION: The improvement in understanding the process that determines the death of an individual and his or her evolution toward brain death allows organization and planning of health policies, optimization of clinical activity and management of organ and tissue procurement processes for transplantation. OBJECTIVE: This study sought to analyze the epidemiological and evolutionary profile of patients with spontaneous subarachnoid hemorrhage (SAH) with a Glasgow Coma Scale score (GCS) ≤8 who entered follow-up in the Neurocritical Patient Monitoring Program (SPN) of Instituto Nacional de Donación y Trasplante (INDT), Uruguay. MATERIALS AND METHODS: SPN, a monitoring and follow-up program for neurocritical patients with GCS ≤ 8, prospectively collected data from 5 public and private intensive care units. A total of 160 patients with SAH with GCS ≤8 in 10 years were identified and analyzed using a 2-step nested model. Firstly, independent risk factors for mortality were identified, tested in different combinations, and one of them was selected using the best correct classification rate. In the second step, risk factors for evolution to brain death were investigated. RESULTS: The mortality of patients with SAH with GCS ≤8 was 68%. Mortality for GCS 3 was 82%, significantly higher than for other values on the scale (P = .0025). Female sex (P = .011) and arterial hypertension (P = .017) were associated with higher mortality. There was no significant association between mortality and age, Acute Physiology and Chronic Health Evaluation score, and Simplified Acute Physiologic Score II. Administration of analgesia and/or sedation was a protective factor (P < .0001). Of the patients who died, 50% were in brain death. We did not find clinical elements capable of identifying an increased probability of developing brain death. CONCLUSIONS: Based on epidemiological data, models capable of improving the understanding of the complex process of death and particularly brain death can be generated. More studies are needed to explore the differential evolutionary behavior of critical neurological illness.

Phenotype of Aeromonas salmonicida sp. salmonicida cyclic adenosine 3',5'-monophosphate receptor protein (Crp) mutants and its virulence in rainbow trout (Oncorhynchus mykiss).

Precise deletion of genes related to virulence can be used as a strategy to produce attenuated bacterial vaccines. Here, we study the deletion of the cyclic-3',5'-adenosine monophosphate (cAMP) receptor protein (Crp) in Aeromonas salmonicida, the aetiologic agent of furunculosis in marine and freshwater fish. The Crp protein is a conserved global regulator, controlling physiology processes, like sugar utilization. Deletion of the crp gene has been utilized in live attenuated vaccines for mammals, birds and warm water fish. Here, we characterized the crp gene and reported the effect of a crp deletion in A. salmonicida virulent and non-virulent isolates. We found that A. salmonicida Δcrp was not able to utilize maltose and other sugars, and its generation time was similar to the wild type. A. salmonicida ∆crp showed a higher ability of cell invasion compared to the wild type. Fish challenges showed that A. salmonicida ∆crp is ~6 times attenuated in Oncorhynchus mykiss and conferred protective immunity against the intraperitoneal challenge with A. salmonicida wild type. We concluded that deletion of A. salmonicida crp influences sugar utilization, cell invasion and virulence. Deletion of crp in A. salmonicida could be considered as part of an effective strategy to develop immersion live attenuated vaccines against furunculosis.

Clinically atypical spitzoid lesions: semi-quantitative histologic index correlation with dermoscopic scores (ABCD rule, 7-point checklist and pattern analysis).

BACKGROUND: The distinction of Spitz and Reed nevi with atypical features from melanoma may be a difficult task. In these cases, the dermoscopic scores could bring variable results and not always correlate with the histologic diagnosis. OBJECTIVE: The aim of this study was to compare the histopathologic and dermoscopic findings in a cohort of clinically atypical Spitz and Reed nevi. METHODS: We retrospectively reviewed 19 cases of atypical Spitz and Reed nevi from our files. We constructed a new semi-quantitative histologic index (HI) based on the reproducible microscopic features, and correlated it with two dermoscopic scores: ABCD and 7-point checklist, as well as with the predominant dermoscopic pattern. RESULTS: The HI values differs significantly when the multicomponent dermoscopic pattern was compared with the rest of patterns (U = 22.5, Z = 2.23, P = 0.01). The ABCD and the 7-point checklist scores did not show statistically significant correlation with the HI. CONCLUSION: To our knowledge, this is the first report in which a semi-quantitative histologic score is compared to different dermoscopic scores in clinically atypical spitzoid lesions. This score can be used to correlate in an objective way the entire histologic picture with the standardized dermoscopic scores. In our series we found a higher HI for those spitzoid lesions with multicomponent pattern.

Hidatidosis muscular como causa de una masa paravertebral / Muscular hydatidosis as a cause of a paravertebral mass

No disponible

Reproductive biology of Echinopsis terscheckii (Cactaceae): the role of nocturnal and diurnal pollinators.

The aim of this study was to analyse the reproductive biology of Echinopsis terscheckii, a species endemic to northwest Argentina that has nocturnal flowers. We expected that this species had a generalised pollination system, with moths and diurnal visitors as the primary pollinators. To test this, we studied the floral biology, breeding system and floral visitors of this species and the effectiveness of nocturnal and diurnal visitors. Floral biology was defined based on floral morphology, floral cycle and nectar production of the flowers. The breeding system and relative contributions of diurnal and nocturnal visitors to fruit and seed set were analysed through field experiments. E. terscheckii flowers opened at sunset and closed the following day. The peak of nectar production occurred at midnight. Flowers were determined to be self-incompatible. Moths, bees and birds were identified as floral visitors. Moths were the most frequent visitors at night, whereas bees were the most frequent visitors during the day. Fruit production by diurnal pollinators was less than that by nocturnal pollinators; among all floral visitors, moths were the most effective pollinators. We have demonstrated for the first time that moths are the primary pollinators of columnar cacti of the genus Echinopsis. Our results suggest that moths might be important pollinators of columnar cactus species with nocturnal flowers in the extra-tropical deserts of South America.

[SERV clinical practice guidelines: management of retinal vein occlusion. Sociedad Española de Retina y Vitreo]. / Guías de práctica clínica de la SERV: manejo de las oclusiones venosas de la retina. Sociedad Española de Retina y Vitreo.

PURPOSE: A guidelines for the management of retinal vein occlusion is presented. This is necessary because at this moment several therapeutic alternatives have been developed although their role is not yet sufficiently defined. METHODS: Review of the literature for evidence published up to date. Relevant literature was identified and the level of evidence graded. Evidence was then assessed for consistency, applicability and clinical impact. The information was contrasted with those guides published in other countries. RESULTS: Taking into account the different options of treatment that are currently used, several modes of action are suggested. The role of the various complementary examinations are discussed and it is recommended that criteria for the treatment are based on clinical, angiographic, and tomographic findings. CONCLUSIONS: Although there is no overall consensus, these guidelines promote a good standard of clinical practise and provide an update of the management of retinal vein occlusion.

Guías de práctica clínica de la SERV: manejo de las oclusiones venosas de la retina / SERV clinical paractice guidelines: management of retinal vein occlusion

Propósito: Se presenta una guía de manejo de las oclusiones venosas retinianas. Esto se hace necesario en un momento en el que han aparecido varias alternativas terapéuticas cuyo papel aún no está completamente definido.MétodosSe revisa la literatura publicada hasta el momento identificando los artículos más relevantes, clasificándolos en base al nivel de evidencia.ResultadosTeniendo en cuenta las distintas opciones de tratamiento que existen en la actualidad, se sugieren varias líneas de actuación. Se discute el papel de las exploraciones complementarias y se recomiendan pautas de tratamiento en base a los hallazgos clínicos, angiográficos y tomográficos.Conclusionesaunque no existe un consenso total, esta guía promueve un estándar de buena práctica clínica y proporciona una actualización del manejo de las oclusiones venosas retinianas (AU)

Purpose: A guidelines for the management of retinal vein occlusion is presented. This is necessary because at this moment several therapeutic alternatives have been developed although their role is not yet sufficiently defined.MethodsReview of the literature for evidence published up to date. Relevant literature was identified and the level of evidence graded. Evidence was then assessed for consistency, applicability and clinical impact. The information was contrasted with those guides published in other countries.ResultsTaking into account the different options of treatment that are currently used, several modes of action are suggested. The role of the various complementary examinations are discussed and it is recommended that criteria for the treatment are based on clinical, angiographic, and tomographic findings.ConclusionsAlthough there is no overall consensus, these guidelines promote a good standard of clinical practise and provide an update of the management of retinal vein occlusion(AU)

Intravitreal bevacizumab (Avastin) for proliferative diabetic retinopathy: 6-months follow-up.

AIMS: To study the effects of intravitreal bevacizumab (Avastin) on retinal neovascularization (RN) in patients with proliferative diabetic retinopathy (PDR). METHODS: Retrospective study of patients with RN due to PDR who were treated with at least one intravitreal injection of 1.25 or 2.5 mg of bevacizumab. Patients underwent ETDRS best-corrected visual acuity (BCVA) testing, ophthalmoscopic examination, optical coherence tomography (OCT), and fluorescein angiography (FA) at baseline and follow-up visits. RESULTS: Forty-four eyes of 33 patients with PDR and a mean age of 57.2-years (range: 23-82 years) participated in the study. Thirty-three eyes (75%) had previous panretinal photocoagulation (PRP). Twenty-seven eyes (61.4%) showed total regression of RN on fundus examination with absence of fluorescein leakage, 15 eyes (34.1%) demonstrated partial regression of RN on fundus examination and FA. Follow-up had a mean of 28.4 weeks (range from 24 to 40 weeks). BCVA and OCT demonstrated improvement (P<0.0001). Three eyes without previous PRP ('naive' eyes) and with vitreous haemorrhage have avoided vitreo-retinal surgery. One eye (2.2%) had PDR progression to tractional retinal detachment requiring vitrectomy, and one eye (2.2%) had vitreous haemorrhage with increased intraocular pressure (ghost cell glaucoma). No systemic adverse events were observed. CONCLUSIONS: Intravitreal bevacizumab resulted in marked regression of RN in patients with PDR and previous PRP, and rapid resolution of vitreous haemorrhage in three naive eyes. Six-months results of intravitreal bevacizumab at doses of 1.25 or 2.5 mg in patients with PDR do not reveal any safety concerns.

Age related maculopathy and diabetes.

PURPOSE: To compare the prevalence of age-related maculopathy (ARM) in a sample of diabetic patients with the general population. METHODS: Binocular indirect ophthalmoscopy, biomicroscopy, and fluorescein angiography. Retrospective prevalence study; descriptive-observational case-control type. Two different groups were analyzed from a sample of 1000 consecutive files of diabetic patients: 1) 65 to 74 years old (n = 263) and 2) 75 years and older (n = 199). Prevalence was compared to that of the general population in a control group and the following epidemiologic studies: Beaver Dam Eye Study, Framingham Eye Study, Blue Mountains Study, and Rotterdam Eye Study. RESULTS: In diabetic patients aged 75 or older, prevalence of ARM was as follows: early lesions 2.51% (5/199), late lesions (ARMD) 2.51% (5/199). In comparison, the risk in patients 75 or older is as follows: control group (ARMD): OR 4.79, 95% CI 1.778-12.033, p (Fisher) 0.0005; Beaver Dam Eye Study (ARMD): OR 2.93, 95% CI 1.152-7.450, p (Fisher): 0; Blue Mountains Eye Study (ARMD): OR 3.06, 95% CI 1.208-7.754, p (Fisher): 0; Framingham Eye Study (ARM): OR 6.73, 95% CI 3.041-14.880, p (Fisher): 0; Rotterdam Eye Study: p (Fisher) 0.133. CONCLUSIONS: 1) A lower prevalence of ARM was found in the sample of diabetic patients aged 75 or older than in the general population (with the exception of the Rotterdam study). 2) Prevalence of ARM was even lower in diabetic patients presenting diabetic retinopathy, whether or not they had been treated with photocoagulation. 3) In diabetic patients, the exudative form was more frequent than the atrophic form, in an inverse ratio to that of the general population.

Tractional retinal detachment following intravitreal bevacizumab (Avastin) in patients with severe proliferative diabetic retinopathy.

AIMS: The aim of this study was to report the development or progression of tractional retinal detachment (TRD) after the injection of intravitreal bevacizumab (Avastin) used as an adjuvant to vitrectomy for the management of severe proliferative diabetic retinopathy (PDR). METHODS: The clinical charts of patients who experienced the development or progression of TRD after an intravitreal injection of 1.25 mg bevacizumab before vitrectomy for the management of PDR were reviewed. RESULTS: Eleven eyes (patients) out of 211 intravitreal injections (5.2%) that developed or had progression of TRD were identified. All eyes had PDR refractory to panretinal photocoagulation (PRP). Nine patients had type 1 diabetes mellitus (DM), and two patients had type 2 DM. Patients had a mean age of 39.5 years (range 22-62 years). In the current study, all patients used insulin administration and had poor glycaemic control (mean HbA(1c) 10.6%). Time from injection to TRD was a mean of 13 days (range 3-31 days). Mean best correct visual acuity (BCVA) at TRD development or progression was logarithm of the minimal angle of resolution (LogMAR) 2.2 (range 1.0-2.6) (mean Snellen equivalent hand motions; range 20/200 to light perception), a statistically significant worsening compared with baseline BCVA (p<0.0001). Eight eyes underwent vitrectomy and three patients refused or were unable to undergo surgery. The final mean BCVA after surgery was LogMAR 0.9 (range 0.2-2.0) (mean Snellen equivalent 20/160; range 20/32 to counting fingers), a statistically significant improvement compared with TRD BCVA (p = 0.002). CONCLUSIONS: TRD may occur or progress shortly following administration of intravitreal bevacizumab in patients with severe PDR.

[Floral biology and pollinators of Trichocereus pasacana (Cactaceae) in Parque Nacional Los Cardones, Argentina]. / Biología floral y polinizadores de Trichocereus pasacana (Cactaceae) en el Parque Nacional Los Cardones, Argentina.

Many columnar cacti are bat pollinated. It has been suggested that this kind of pollination would be more important in tropical than in temperate regions where flowers are open only one night. Thrichocereus pasacana produces big and resistant white flowers. We analyzed flower characteristics, floral cycle, stigmatic receptivity, nectar production, pollen presence and floral visitors in a T. pasacana population at National Park Los Cardones (Salta, Argentina) in November 1997. Flower features were constant between individuals of the population. Flowers start opening at evening and anthesis time is from 18 to 40 hs. The estigma was receptive throughout the floral cycle. Anther dehiscence occurs with flower opening. Nectar production was highest between 18 to 24 hs. Although T. pasacana are open during the night, floral visitors are diurnal. The most frequent was Xylocopa sp. In the study area, nectarivorous bats were not detected. The morphological features of T. pasacana flowers were similar but bigger compared to other columnar cacti. Anthesis time was also longer while nectar production was lower. T. pasacana pollination at National Park Los Cardones is done by bees.

[Seeds germination of Caesalpinia paraguariensis (Fabaceae): scarificator agents and cattle effects]. / Germinación de semillas de Caesalpinia paraguariensis (Fabaceae): agentes escarificadores y efecto del ganado.

The tree Caesalpinia paraguariensis grows in the Chaco region, Argentina. Fruits are indehiscent with many seeds. This species is an important source of wood and the fruits are consumed by cattle in Salta province. We studied seed germination under chemical, mechanical and biological scarification. Seeds from controls (without scarification) and those with biological scarification had a smaller (and similar) germination rate. The non-germinated seeds from biological treatments were mechanically scarified and their germination rate was similar to others under the mechanical treatment. Passage by digestive tracts would not enhance germination because viable seeds are still dormant due to their hard coats.

Bilateral birooted maxillary primary canines: report of two cases.

X-ray examination disclosed bifurcation of both maxillary canine teeth in two unrelated patients, both four-year-old children. All other dental findings were unremarkable and their medical histories were noncontributory. Bifurcation of primary canines is an extremely rare condition.

The needleless syringe: efficacy of anesthesia and patient preference in child dental patients.

Delivery of local anesthesia in dentistry is primarily by way of a needle-tipped syringe. This procedure, when used on children, is often stressful and sometimes painful for the patient. The Syrijet is an instrument which delivers anesthesia without the use of a needle. This is accomplished by delivering the anesthetic solution under high compressive forces. The subjects were thirty-four children ranging in age between 5 and 15 years, on whom forty-five dental procedures were completed. There was a statistically significant difference in favor of the instrument, with twenty-five subjects reporting a preference for it. The instrument was completely successful in providing anesthesia in thirty-six of the forty-five procedures.

Chlorhexidine as an oral hygiene adjunct for cyclosporine-induced gingival hyperplasia.

Recent advances in surgical technique and chemotherapeutic procedures have greatly increased the survival rates of organ transplantation patients. Of dental importance is the widespread use of the immunosuppressive agent cyclosporine in this special-patient population, a drug that has the potential to cause severe gingival hyperplasia as a side effect. A case is presented illustrating the use of the plaque-inhibitor chlorhexidine as a therapeutic adjunct in possibly arresting this gingival condition.

Cotton roll isolation versus Vac-Ejector isolation.

A visible-light-cured, white pit-and-fissure sealant was applied to 523 teeth in school children using either cotton rolls or a VacEjector for isolation. After a minimum of six months, the patients were recalled and the retention of the sealants was evaluated. No significant difference in sealant retention was found between the two isolation methods.

Dental management of patients after liver transplantation.

Liver transplantation over the past 10 years has become a nonexperimental therapy for patients with end-stage liver disease and offers hope to many for whom no treatment was previously available. As more patients undergo liver transplantation and survival rates continue to improve, the dental profession must adopt a protocol for dealing with these patients. With this in mind, a protocol for dental management of the patient who has had a liver transplant is presented. Two cases are presented to illustrate the importance of dental intervention.