523 research outputs found
Modeling the Effect of Propofol and Remifentanil Combinations for Sedation-Analgesia in Endoscopic Procedures Using an Adaptive Neuro Fuzzy Inference System (ANFIS)
BACKGROUND:
The increasing demand for anesthetic procedures in the gastrointestinal endoscopy area has not been followed by a similar increase in the methods to provide and control sedation and analgesia for these patients. In this study, we evaluated different combinations of propofol and remifentanil, administered through a target-controlled infusion system, to estimate the optimal concentrations as well as the best way to control the sedative effects induced by the combinations of drugs in patients undergoing ultrasonographic endoscopy.
METHODS:
One hundred twenty patients undergoing ultrasonographic endoscopy were randomized to receive, by means of a target-controlled infusion system, a fixed effect-site concentration of either propofol or remifentanil of 8 different possible concentrations, allowing adjustment of the concentrations of the other drug. Predicted effect-site propofol (C(e)pro) and remifentanil (C(e)remi) concentrations, parameters derived from auditory evoked potential, autoregressive auditory evoked potential index (AAI/2) and electroencephalogram (bispectral index [BIS] and index of consciousness [IoC]) signals, as well as categorical scores of sedation (Ramsay Sedation Scale [RSS] score) in the presence or absence of nociceptive stimulation, were collected, recorded, and analyzed using an Adaptive Neuro Fuzzy Inference System. The models described for the relationship between C(e)pro and C(e)remi versus AAI/2, BIS, and IoC were diagnosed for inaccuracy using median absolute performance error (MDAPE) and median root mean squared error (MDRMSE), and for bias using median performance error (MDPE). The models were validated in a prospective group of 68 new patients receiving different combinations of propofol and remifentanil. The predictive ability (P(k)) of AAI/2, BIS, and IoC with respect to the sedation level, RSS score, was also explored.
RESULTS:
Data from 110 patients were analyzed in the training group. The resulting estimated models had an MDAPE of 32.87, 12.89, and 8.77; an MDRMSE of 17.01, 12.81, and 9.40; and an MDPE of -1.86, 3.97, and 2.21 for AAI/2, BIS, and IoC, respectively, in the absence of stimulation and similar values under stimulation. P(k) values were 0.82, 0.81, and 0.85 for AAI/2, BIS, and IoC, respectively. The model predicted the prospective validation data with an MDAPE of 34.81, 14.78, and 10.25; an MDRMSE of 16.81, 15.91, and 11.81; an MDPE of -8.37, 5.65, and -1.43; and P(k) values of 0.81, 0.8, and 0.8 for AAI/2, BIS, and IoC, respectively.
CONCLUSION:
A model relating C(e)pro and C(e)remi to AAI/2, BIS, and IoC has been developed and prospectively validated. Based on these models, the (C(e)pro, C(e)remi) concentration pairs that provide an RSS score of 4 range from (1.8 μg·mL(-1), 1.5 ng·mL(-1)) to (2.7 μg·mL(-1), 0 ng·mL(-1)). These concentrations are associated with AAI/2 values of 25 to 30, BIS of 71 to 75, and IoC of 72 to 76. The presence of noxious stimulation increases the requirements of C(e)pro and C(e)remi to achieve the same degree of sedative effects
Microbial community changes induced by Managed Aquifer Recharge activities: linking hydrogeological and biological processes
Managed Aquifer Recharge (MAR) is a technique used worldwide to increase the
availability of water resources. We study how MAR modifies microbial
ecosystems and its implications for enhancing biodegradation processes to
eventually improve groundwater quality. We compare soil and groundwater
samples taken from a MAR facility located in NE Spain during recharge (with
the facility operating continuously for several months) and after 4 months
of no recharge. The study demonstrates a strong correlation between soil and
water microbial prints with respect to sampling location along the mapped
infiltration path. In particular, managed recharge practices disrupt
groundwater ecosystems by modifying diversity indices and the composition of
microbial communities, indicating that infiltration favors the growth of
certain populations. Analysis of the genetic profiles showed the presence of
nine different bacterial phyla in the facility, revealing high biological
diversity at the highest taxonomic range. In fact, the microbial population
patterns under recharge conditions agree with the intermediate disturbance
hypothesis (IDH). Moreover, DNA sequence analysis of excised denaturing gradient gel electrophoresis (DGGE) band patterns
revealed the existence of indicator species linked to MAR, most notably
Dehalogenimonas sp., Nitrospira sp. and Vogesella sp.. Our real facility multidisciplinary study (hydrological, geochemical and
microbial), involving soil and groundwater samples, indicates that MAR is a
naturally based, passive and efficient technique with broad implications for
the biodegradation of pollutants dissolved in water.</p
Hospitalización pediátrica evitable en la Comunidad Valenciana y Cataluña
ResumenObjetivoEstimar las tasas de hospitalización pediátrica evitable por áreas en la Comunidad Valenciana y sectores en Cataluña, y analizar su relación con el nivel socioeconómico o el desarrollo de la atención primaria.MétodoSe estudiaron las hospitalizaciones pediátricas evitables (0-14 años) a partir del Conjunto Mínimo de Datos Básicos del Alta Hospitalaria de la Comunidad Valenciana y de Cataluña (1993-1994). Las variables a estudio fueron: edad, género, nivel socioeconómico y cobertura del nuevo modelo de atención primaria. Se calcularon las tasas brutas y estandarizadas por edad y se realizó una descripción de su variación en áreas y sectores. Se analizó la relación entre las tasas y las características socioeconómicas y de la atención primaria.ResultadosLas hospitalizaciones pediátricas evitables representaron el 21% de todas las hospitalizaciones pediátricas en la Comunidad Valenciana y el 15% en Cataluña. Las tasas brutas en las áreas de la Comunidad Valenciana oscilaron entre 5,7 y 12,7 en 1993 y 6,6 y 17,8 en 1994. La razón de tasas fue de 2,2 y el coeficiente de variación de 37% en 1993 y de 2,7 y 48% respectivamente, en 1994. En los sectores de Cataluña oscilaron entre 2,7 y 24,3 en 1993 y 1,4 y 23,8 en 1994; la razón de tasas fue de 9 y el coeficiente de variación de 52% en 1993, y de 7 y 42% en 1994 respectivamente. Las diferencias encontradas fueron significativas (p < 0,005). No hubo correlación significativa entre el nivel socioeconómico y desarrollo de la atención primaria y las tasas de hospitalización pediátrica evitable por áreas o sectores.ConclusionesLas hospitalizaciones pediátricas evitables suponen una proporción importante de las hospitalizaciones pediátricas. Existe variación en las tasas de hospitalización pediátrica evitable por áreas y sectores, no asociada a los indicadores de nivel socioeconómico y atención primaria utilizados.SummaryObjectiveTo estimate the rates of avoidable pediatric hospitalization in the health areas of the Valencian Community and health sectors of Catalonia, and to analyze if they are related to socioeconomic level or development of primary care.MethodAvoilable paediatric (0-14 years old) hospitalizations were analyzed using the Minimum Basic Data Set of Hospital Discharge in two Autonomous Regions: the Valencian Community and Catalonia (1993-1994). Variables analyzed included age, gender, socioeconomic level and coverage by the new model of primary care. Crude and standardized rates for age were calculated and the variation in areas and sectors was assessed. The association between rates and socioeconomic and primary care characteristics was analyzed.ResultsAvoidable paediatric hospitalizations represent 21% of all paediatric hospitalizations in the Valencian Community and 15% in Catalonia. Crude rates for Valencian Community ranged between 5.7 and 12.7 in 1993 and 6.6 and 17.8 in 1994; extremal quotient was 2.2 and coefficient of variation 37% in 1993 and 2.7 and 48% respectively in 1994. For Catalonia they ranged between 2.7 and 24.3 in 1993 and 1.4 and 23.8 in 1994; extremal quotient was 9 and coefficient of variation 52% in 1993, and 7 and 42% in 1994 respectively. All these differences were significant (p < 0.005). There was no significant correlation between socieconomic level and development of primary health care and rates of avoidable paediatric hospitalization by health areas or sectors.ConclusionsAvoidable paediatric hospitalization represent a significant proportion of paediatric hospitalizations. There are differences in avoidable paediatric hospitalization rates by health areas and sectors, not associated with socieconomic level and primary care indicators
Estrogen metabolism and mammographic density in postmenopausal women : a cross-sectional study
Background: Prospective studies have consistently found that postmenopausal breast cancer risk increases with circulating estrogens; however, findings from studies of estrogens and mammographic density (MD), an intermediate marker of breast cancer risk, have been inconsistent. We investigated the cross-sectional associations of urinary estrogens, and their 2-, 4-, and 16-hydroxylated metabolites with MD. Methods: Postmenopausal women without breast cancer (n = 194), ages 48 to 82 years, and reporting no current menopausal hormone therapy use were enrolled at a clinic in Western NY in 2005. Urinary estrogens and estrogen metabolites were measured using mass spectrometry. Percent MD and dense area (cm2) were measured using computer-assisted analyses of digitized films. Linear regression models were used to estimate associations of log-transformed estrogen measures with MD while adjusting for age, body mass index (BMI), parity, and past hormone therapy use. Results: Urinary concentrations of most individual estrogens and metabolites were not associated with MD; however, across the interdecile range of the ratio of parent estrogens (estrone and estradiol) to their metabolites, MD increased by 6.8 percentage points (P = 0.02) and dense area increased by 10.3 cm2 (P = 0.03). Across the interdecile ranges of the ratios of 2-, 4-, and 16-hydroxylation pathways to the parent estrogens, MD declined by 6.2 (P = 0.03), 6.4 (P = 0.04), and 5.7 (P = 0.05) percentage points, respectively. All associations remained apparent in models without adjustment for BMI. Conclusion: In this study of postmenopausal women, less extensive hydroxylation of parent estrogens was associated with higher MD. Impact: Hydroxylation of estrogens may modulate postmenopausal breast cancer risk through a pathway involving MD
Factores influyentes en el tiempo hasta la progresión bioquímica después de prostatectomía radical
INTRODUCTION:
We assessed the time-influencing clinical-pathological factors for biochemical progression of an equal series of patients from a single institution.
MATERIALS AND METHODS:
Retrospective analysis of 278 patients with biochemical progression following prostatectomy. We considered biochemical progression to be PSA>0.4 ng/ml. We performed the trial using the Cox model (univariate and multivariate) and using the Student's t-test to compare averages.
RESULTS:
With a mean follow-up of 4 (±3 DE) years, the univariate study showed a mean until progression for the Gleason score 2-6 in the biopsy of 824 days and 543 for the Gleason score 7-10 (p=0.003). For negative surgical margins, the mean was 920 days and 545 for positive margins (p=0.0001). In the case of a Gleason score 2-7 in the specimen, the mean was 806 days and 501 for a Gleason score 8-10 (p=0.001). Lastly, the mean for the cases with Ki-67 negative in the specimen ( 10%) (p=0.003). In the multivariate study, Ki-67 (OR 1.028; IC 95% 1-1.01; p=0.0001) and Gleason score 8-10 (OR 1.62; IC 95% 1.5-2.45; p=0.026) in the specimen, and initial PSA >10 ng/ml (OR 1.02; IC 95% 1.01-1.04; p=0.0001) were independent variables. Using these variables, we designed a predictive model with three groups. The time until the progression of each group was 1,081, 551 and 218 days respectively.
CONCLUSION:
The Gleason score 7-10 in the prostate biopsy, the presence of Ki-67, the positive margins and the Gleason score 8-10 in the specimen, and the initial PSA > 10 ng/ml are time-influencing factors until biochemical progression. Pathological Gleason score 8-10, PSA > 10 ng/ml and Ki-67 are independent factors
The effect of internal pressure on the tetragonal to monoclinic structural phase transition in ReOFeAs: the case of NdOFeAs
We report the temperature dependent x-ray powder diffraction of the
quaternary compound NdOFeAs (also called NdFeAsO) in the range between 300 K
and 95 K. We have detected the structural phase transition from the tetragonal
phase, with P4/nmm space group, to the orthorhombic or monoclinic phase, with
Cmma or P112/a1 (or P2/c) space group, over a broad temperature range from 150
K to 120 K, centered at T0 ~137 K. Therefore the temperature of this structural
phase transition is strongly reduced, by about ~30K, by increasing the internal
chemical pressure going from LaOFeAs to NdOFeAs. In contrast the
superconducting critical temperature increases from 27 K to 51 K going from
LaOFeAs to NdOFeAs doped samples. This result shows that the normal striped
orthorhombic Cmma phase competes with the superconducting tetragonal phase.
Therefore by controlling the internal chemical pressure in new materials it
should be possible to push toward zero the critical temperature T0 of the
structural phase transition, giving the striped phase, in order to get
superconductors with higher Tc.Comment: 9 pages, 3 figure
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