A High-Efficiency Capacitor-Based Battery Equalizer for Electric Vehicles.

Technology in electric vehicles has increased substantially in the past decade. Moreover, it is projected to grow at record highs in the coming years since these vehicles are needed to reduce the contamination related to the transportation sector. One of the essential elements of an electric car is its battery, due to its cost. Batteries comprise parallel and series-connected cell arrangements to meet the power system requirements. Therefore, they require a cell equalizer circuit to preserve their safety and correct operation. These circuits keep a specific variable of all cells, such as the voltage, within a particular range. Within cell equalizers, capacitor-based ones are very common as they have many desirable characteristics of the ideal equalizer. In this work, an equalizer based on the switched-capacitor is proposed. A switch is added to this technology that allows the disconnection of the capacitor from the circuit. In this way, an equalization process can be achieved without excess transfers. Therefore, a more efficient and faster process can be completed. In addition, it allows another equalization variable to be used, such as the state of charge. This paper studies the operation, power design, and controller design of the converter. Moreover, the proposed equalizer was compared to other capacitor-based architectures. Finally, simulation results were presented to validate the theoretical analysis.

LDR brachytherapy offers superior tumor control to single-fraction HDR prostate brachytherapy: A prospective study.

PURPOSE: To compare the clinical outcomes of single-fraction high-dose-rate (HDR) brachytherapy and single-fraction low-dose-rate (LDR) brachytherapy as the sole treatment for primary prostate cancer. MATERIAL AND METHODS: A quasi-randomized study that allocated, from March 2008 to February 2012, 129 low and intermediate risk prostate cancer patients to one single-fraction HDR of 19 Gy (61 patients) or to a 145 Gy 125 I LDR permanent implant (68 patients. Biochemical relapse-free survival (bRFS) and overall survival (OS) were compared using the Kaplan-Meier method and Cox regression analysis. RESULTS: After a median follow-up of 72 months in the HDR group, 26 patients relapsed, and after a median follow-up of 84 months in the LDR group, 7 patients relapsed (p < 0.0001). The 5-year bRFS was significantly better for the LDR group than for the HDR group (93.7% and 61.1%, respectively) (p < 0.0001). The 5-year OS also was significantly better in the LDR group (95.5% vs. 89.9%) (p = 0.0436). CONCLUSIONS: Permanent LDR prostate implant brachytherapy offers better clinical outcomes than single-fraction HDR for prostate cancer.

An updated examination of the perception of barriers for pharmacogenomics implementation and the usefulness of drug/gene pairs in Latin America and the Caribbean.

Pharmacogenomics (PGx) is considered an emergent field in developing countries. Research on PGx in the Latin American and the Caribbean (LAC) region remains scarce, with limited information in some populations. Thus, extrapolations are complicated, especially in mixed populations. In this paper, we reviewed and analyzed pharmacogenomic knowledge among the LAC scientific and clinical community and examined barriers to clinical application. We performed a search for publications and clinical trials in the field worldwide and evaluated the contribution of LAC. Next, we conducted a regional structured survey that evaluated a list of 14 potential barriers to the clinical implementation of biomarkers based on their importance. In addition, a paired list of 54 genes/drugs was analyzed to determine an association between biomarkers and response to genomic medicine. This survey was compared to a previous survey performed in 2014 to assess progress in the region. The search results indicated that Latin American and Caribbean countries have contributed 3.44% of the total publications and 2.45% of the PGx-related clinical trials worldwide thus far. A total of 106 professionals from 17 countries answered the survey. Six major groups of barriers were identified. Despite the region's continuous efforts in the last decade, the primary barrier to PGx implementation in LAC remains the same, the "need for guidelines, processes, and protocols for the clinical application of pharmacogenetics/pharmacogenomics". Cost-effectiveness issues are considered critical factors in the region. Items related to the reluctance of clinicians are currently less relevant. Based on the survey results, the highest ranked (96%-99%) gene/drug pairs perceived as important were CYP2D6/tamoxifen, CYP3A5/tacrolimus, CYP2D6/opioids, DPYD/fluoropyrimidines, TMPT/thiopurines, CYP2D6/tricyclic antidepressants, CYP2C19/tricyclic antidepressants, NUDT15/thiopurines, CYP2B6/efavirenz, and CYP2C19/clopidogrel. In conclusion, although the global contribution of LAC countries remains low in the PGx field, a relevant improvement has been observed in the region. The perception of the usefulness of PGx tests in biomedical community has drastically changed, raising awareness among physicians, which suggests a promising future in the clinical applications of PGx in LAC.

Total Syntheses of Scabrolide A and Yonarolide.

The concise total syntheses of oxidized norcembranoid terpenoids (-)-scabrolide A and (-)-yonarolide have been accomplished in 10 and 11 steps, respectively. The carbocyclic skeleton was efficiently constructed from two chiral-pool-derived fragments, including a [5,5]-bicyclic lactone accessed through a powerful Ni-catalyzed pentannulation of functionalized cyclopentenone with methylenecyclopropane and subsequent fragmentation. Additional features included a Liebeskind-Srogl coupling, induction of a cyclization/elimination cascade by a zinc-amido base, and installation of a sensitive enedione motif by late-stage γ-oxidation.

A New Methodology for a Retrofitted Self-tuned Controller with Open-Source FPGA.

Servo systems are feedback control systems characterized by position, speed, and/or acceleration outputs. Nowadays, industrial advances make the electronic stages in these systems obsolete compared to the mechanical elements, which generates a recurring problem in technological, commercial and industrial applications. This article presents a methodology for the development of an open-architecture controller that is based on reconfigurable hardware under the open source concept for servo applications. The most outstanding contribution of this paper is the implementation of a Genetic Algorithm for online self tuning with a focus on both high-quality servo control and reduction of vibrations during the positioning of a linear motion system. The proposed techniques have been validated on a real platform and form a novel, effective approach as compared to the conventional tuning methods that employ empirical or analytical solutions and cannot improve their parameter set. The controller was elaborated from the Graphical User Interface to the logical implementation while using free tools. This approach also allows for modification and updates to be made easily, thereby reducing the susceptibility to obsolescence. A comparison of the logical implementation with the manufacturer software was also conducted in order to test the performance of free tools in FPGAs. The Graphical User Interface developed in Python presents features, such as speed profiling, controller auto-tuning, measurement of main parameters, and monitoring of servo system vibrations.

A PID-Type Fuzzy Logic Controller-Based Approach for Motion Control Applications.

Motion control is widely used in industrial applications since machinery, robots, conveyor bands use smooth movements in order to reach a desired position decreasing the steady error and energy consumption. In this paper, a new Proportional-Integral-Derivative (PID) -type fuzzy logic controller (FLC) tuning strategy that is based on direct fuzzy relations is proposed in order to compute the PID constants. The motion control algorithm is composed by PID-type FLC and S-curve velocity profile, which is developed in C/C++ programming language; therefore, a license is not required to reproduce the code among embedded systems. The self-tuning controller is carried out online, it depends on error and change in error to adapt according to the system variations. The experimental results were obtained in a linear platform integrated by a direct current (DC) motor connected to an encoder to measure the position. The shaft of the motor is connected to an endless screw; a cart is placed on the screw to control its position. The rise time, overshoot, and settling time values measured in the experimentation are 0.124 s, 8.985% and 0.248 s, respectively. These results presented in part 6 demonstrate the performance of the controller, since the rise time and settling time are improved according to the state of the art. Besides, these parameters are compared with different control architectures reported in the literature. This comparison is made after applying a step input signal to the DC motor.

Promoting Thermodynamically Unfavorable [3,3] Rearrangements by Chemoselective Reduction.

Herein described is a strategy for promoting thermodynamically unfavorable [3,3] Cope rearrangements. 3,3-Dicyano-1,5-dienes that are resistant to the thermal rearrangement can be promoted under reductive conditions. The reduced Cope products are versatile, bifunctional building blocks.

Effectiveness of flossing loops in the control of the gingival health.

BACKGROUND: One of the key factor in the good condition of periodontal tissues is their daily hygiene. Oral hygiene techniques such brushing and a good interdental hygiene by correct flossing are very important. The aim of this study is to compare the use of dental floss in a loop vs traditional floss in the control of Loe-Silness Gingival Index (IG), Turesky´s Plaque Index (IPT), Gingival Bleeding Index (IS) and the values of interleukin 6 (IL-6) and interleukin 8 (IL-8). MATERIAL AND METHODS: A comparative study of 40 patients in which each patient was his own control, using during 45 days each one of the devices (new loop floss and conventional floss) of interdental hygiene analysed. Data for Loe-Silness Gingival Index (IG), Turesky´s Plaque Index (IPT), Gingival Bleeding Index (IS) and the values of interleukin 6 (IL-6) and interleukin 8 (IL-8)were collected and measured in every visit for every type of interdental hygiene device. RESULTS: Our data indicates that the rate of Turesky´s Plaque Index presented statistically significant differences between groups (loop: 1.66 ± 0.8; traditional: 1.12 ± 0.8; p<0.0001). The rest of the indices studied showed no statistically significant differences. CONCLUSIONS: The creation of new dental floss designs try to make their use easier and more sensitive, and plaque removal more effective. The loop design can facilitate interdental hygiene, reaching similar effectiveness than traditional floss, improving some indicators, such as Turesky´s Plaque Index. Key words:Dental floss, bacterial plaque, loop floss, plaque index, periodontal diseases.

Combination of straight and tilted implants for supporting screw-retained dental prostheses in atrophic posterior maxillae: A 2-year prospective study.

OBJECTIVES: To evaluate the two-year survival rate (SR) and marginal bone loss (MBL) of fixed dental prostheses (FDPs) supported by straight (S) and tilted (T) implants under the influence of diverse study variables. METHODS: A prospective investigation comprising 21 patients provided with a total of 27 maxillary screw-retained restorations fixed to 70 dental implants was developed. Two groups of implants were considered depending on their inclination with respect to the occlusal plane: Group 1 (S, n=37): straight/axial implants and Group 2 (T, n=33): tilted/angled fixations. Each FDP was supported by a combination of S and T implants. SR and MBL were assessed at the time of loading and two years after surgery. Patient-, surgical- and/or rehabilitation-related information was gathered. Data were statistically analysed at the α=0.05 significance level. RESULTS: After 24 months, a 100% SR was achieved and the MBL of S and T implants were statistically similar. T implants located in the molar region showed lower MBL than did those replacing premolars (p=0.031). CONCLUSIONS: Upright and angled fixations inserted at posterior maxillary areas resulted in comparable survival rates and peri-implant MBL after two years. The marginal bone resorption around tilted implants depended on their location. CLINICAL SIGNIFICANCE: Screw-retained restorations fixed to straight and tilted implants seem to be a safe treatment option in posterior atrophic maxillae.

The effects of a topical gel containing chitosan, 0,2% chlorhexidine, allantoin and despanthenol on the wound healing process subsequent to impacted lower third molar extraction

BACKGROUND: Despite efforts to prevent postoperative discomfort, there are still many immediate side effects associated with the surgical extraction of impacted lower third molars. Cicatrization is a physiological process through which the loss of integrity of oral mucosa is recovered and damaged tissues are repaired. Bexident Post (ISDIN, Spain) is a topical gel that contains chitosan, 0.2% chlorhexidine, allantoin and dexpanthenol. While this gel has many clinical indications, there are no published clinical trials evaluating its use in impacted mandibular third molar surgery. This study aims to clinically evaluate the efficacy of a gel containing chitosan, 0.2% chlorhexidine, allantoin and dexpanthenol on wound healing and reduction of postoperative side effects and complications after extraction of an impacted mandibular third molar. MATERIAL AND METHODS: A split-mouth design study was carried out on a total of 50 bilaterally and symmetrically impacted third molar extractions, which were randomly placed into either a control group (CG=25) or an experimental group (EG=25). Patients were all informed of the purpose of the study and provided written consent. All procedures were carried out by the same dental practitioner, in accordance with standard surgical protocol. A different dental practitioner, unaware of which treatment had been applied, provided follow-up care. The EG applied 10 ml of topical gel composed of chitosan, 0.2% chlorhexidine, allantoin and dexpanthenol to the surgical wound three times a day for 10 days, patients in the CG did not apply any gel. RESULTS: The groups were homogeneous insofar as potentially confounding variables. No significant findings were found regarding postoperative swelling and pain. Neither of the groups displayed poor healing or infectious complications of the wound during the postoperative period. In all the recorded follow-ups (Day 7 p = 0.001, and Day 14 p = 0.01), the wound's aesthetic appearance was better in the EG. Overall treatment tolerance was satisfactory and similar in both groups. CONCLUSIONS: The gel composed of chitosan, 0.2% chlorhexidine, allantoin and dexpanthenol did not aid in patients' postoperative comfort; however, improved wound healing was observed

What Are the Histologic Effects of Surgical and Orthodontic Treatment on the Gingiva of Palatal Impacted Canines?

PURPOSE: To histologically evaluate changes in the marginal gingiva of palatal impacted maxillary canines after surgical exposure and orthodontic treatment. MATERIALS AND METHODS: A prospective case-and-control study was conducted of 10 patients presenting with bilateral palatal impaction of the maxillary canines. All patients underwent surgical exposure of the impacted canines with an open-window technique, which was followed by orthodontic treatment to achieve proper arch alignment. Once the treatment was finalized, 4 samples of marginal gingival tissue from each patient were taken for histologic study. The 4 samples consisted of 1 from each of the repositioned maxillary canines (case teeth) and 1 from each of their respective adjacent first premolars (control teeth). RESULTS: Histologic examination of the case teeth tissue samples showed microscopic changes mainly in the nonkeratinized epithelium and connective tissue, whereas changes in the keratinized epithelium remained minimal. The control teeth showed a greater inflammatory reaction in the nonkeratinized epithelium. CONCLUSION: Orthodontic treatment of impacted maxillary canines used in conjunction with an open-window surgical technique results in predictable orthodontic eruption with few periodontal discrepancies of the marginal gingiva compared with their adjacent first premolars.

FPGA-based smart sensor for drought stress detection in tomato plants using novel physiological variables and discrete wavelet transform.

Soil drought represents one of the most dangerous stresses for plants. It impacts the yield and quality of crops, and if it remains undetected for a long time, the entire crop could be lost. However, for some plants a certain amount of drought stress improves specific characteristics. In such cases, a device capable of detecting and quantifying the impact of drought stress in plants is desirable. This article focuses on testing if the monitoring of physiological process through a gas exchange methodology provides enough information to detect drought stress conditions in plants. The experiment consists of using a set of smart sensors based on Field Programmable Gate Arrays (FPGAs) to monitor a group of plants under controlled drought conditions. The main objective was to use different digital signal processing techniques such as the Discrete Wavelet Transform (DWT) to explore the response of plant physiological processes to drought. Also, an index-based methodology was utilized to compensate the spatial variation inside the greenhouse. As a result, differences between treatments were determined to be independent of climate variations inside the greenhouse. Finally, after using the DWT as digital filter, results demonstrated that the proposed system is capable to reject high frequency noise and to detect drought conditions.

Neumonía aguda grave de la comunidad en menores de 65 años sin comorbilidades conocidas previamente: estudio multicéntrico retrospectivo / Severe community acquired pneumonia in healthy adults: a multicenter retrospective study

Objetivo: analizar las características epidemiológicas, clínicas y de estudios complementarios en pacientes jóvenes y sanos con neumonía aguda grave de la comunidad (NACG). Material y Método: evaluación retrospectiva de historias clínicas de adultos menores de 65 años, sin comorbilidades, internados con NACG entre 1998 y 2008. Resultados: se identificaron 40 pacientes (M/F = 0.48), edad promedio 37.8 ± 14.1años (16-61). El 42.5% requirió ventilación mecánica y el 57.5% inotrópicos. La PaO2/FiO2 inicial fue 203.6 ± 91.4 mmHg (50-366.7) y las anomalías de laboratorio más frecuentesincluyeron anemia, leucocitosis, hipoalbuminemia y urea y creatinina elevadas. El tratamiento antibiótico empírico consistió en ceftriaxona o ß-lactámico/inhibidor de ß-lactamasas (BL) + macrólido en el 70% de los casos. La etiología se reveló en el 50%,los patógenos y su frecuencia fueron: Streptococcus Pneumoniae, 35%; Leptospira, 15%; Hantavirus y Mycoplasma pneumoniae, 10% y Legionella pneumophila, Pneumocystisjirovecii, Histoplasma capsulatum, Klebsiella pneumoniae, Haemophilus influenzae BL (-) y Staphylococcus aureus sensible a meticilina, 5%. El 77.5% de los pacientes presentócomplicaciones, las más frecuentes fueron shock, insuficiencia respiratoria, insuficiencia renal aguda y derrame pleural. Ocho pacientes presentaron comorbilidades desconocidas,incluyendo HIV positivo, diabetes mellitus, asma, insuficiencia cardíaca e hipotiroidismo. La mortalidad fue 12.5%. Hipotensión arterial diastólica, taquicardia, requerimiento dehemodiálisis y tratamiento inadecuado se asociaron independientemente a mortalidad. Conclusiones: el 20% de los menores de 65 años con NACG, presumiblemente sanos, tenían comorbilidades. El patógeno más frecuente fue neumococo y la mortalidad se asoció a la gravedad de la sepsis e inadecuación del tratamiento.

Aims: to analyze epidemiologic, clinical and other abnormalities in healthy young adults with severe community acquired pneumonia (SCAP). Methods: retrospective analysis of clinical records of adults younger than 65 years, with SCAP and without previously known comorbidities, admitted from 1998 to 2008. Results: forty patients were included (M/F = 0.48), age 37.8 ± 14.1 years (range 16 - 61). Mechanical ventilation was used in 42.5% and vasopressors in 57.5% of patients. Initial PaO2/FIO2 ratio was 203.6 ± 91.4 mmHg (50 - 366.7); frequent laboratory abnormalities included: anemia, leukocytosis, hypoalbuminemia and high urea and creatinine levels.The empiric antimicrobial therapy was ceftriaxone or ß-lactam/ß - lactamases (BL) inhibitor plus macrolide in 70% of cases. The etiology was established in 50%; the specific pathogens were: Streptococcus pneumoniae, 35%; Leptospira, 15%; Hantavirus and Mycoplasma pneumoniae, 10%; and Legionella pneumophila, Pneumocystisjirovecii, Histoplasma capsulatum, Klebsiella pneumoniae, Haemophilus influenzae BL (-) and methicillin susceptible Staphylococcus aureus, 5%. Complications were present in 77.5% including shock, respiratory failure, acute renal failure and pleural effusion.Eight patients presented previously unknown comorbidities including HIV infection, diabetes mellitus, asthma, congestive cardiac failure and hypothyroidism. Mortality was 12.5 %. Diastolic arterial hypotension, taquichycardia, requirement of hemodialysis and inadequate therapy were significantly associated to mortality. Conclusions: 20% of young and presumably healthy adults with SCAP had comorbidities. S. pneumoniae was the commonest pathogen; mortality was associated with severity of sepsis and inadequate therapy.

Características de la neumonía adquirida en la comunidad por neumococo y micoplasma / Characteristics of community-acquired pneumonia due to neumococcus and mycoplasma

Se estudiaron en forma prospectiva pacientes con diagnóstico de neumonía adquirida en la comunidad (NAC) con criterios de internación con el objetivo de determinar las características clínicas, radiológicas, bioquímicas y evolutivas en pacientes con diagnóstico microbiológico definitivo y evaluar si existen diferencias entre las neumonías causadas por neumococo y micoplasma. Se incluyeron durante un periodo de observación de 24 meses, 49 neumonías producidas por Streptococcus pneumoniae con aislamiento en hemocultivo y 22 por Mycoplasma pneumoniae diagnosticados por PCR de hisopado nasofaríngeo (HNF). Se evaluaron la edad, comorbilidades, cuadro clínico, variables de laboratorio y radiológicas, evolución clínica y criterios de severidad. Nuestro grupo tenía un promedio de edad de 57años, con un elevado porcentaje de comorbilidades y de valores de Pneumonia Severity Index (PSI). Se observó una tendencia no significativa en los casos con micoplasma a ser más añosos, con mayor porcentaje de comorbilidades; y en los casos de etiología por neumococo, mayor porcentaje de hipotensión, hipoalbuminemia severa, compromiso de más de un lóbulo, alteraciones hepáticas y requerimiento de UTI; la única diferencia significativa fue el desarrollo de compromiso renal para neumococo.En la población estudiada no existieron variables que permitieran predecir el agente etiológico.

Patients with community-acquired pneumonia (CAP) meeting the criteria for hospitalization and with a definitive etiological diagnosis were prospectively studied. The objective was to determine their clinical, radiological, biochemical and evolutionary characteristics and to assess whether there are differences between pneumonia caused by pneumococcus and mycoplasma. During an observation period of 24 months, 49 CAP cases caused by Streptococcus pneumoniae isolated from blood cultures and 22 CAP cases caused by Mycoplasma pneumoniae diagnosed by PCR testing of oropharyngeal swabs were included. The age of patients, presence of comorbidities, clinical picture, laboratory and radiological variables, clinical evolution and degree of severity were evaluated. The mean age of the group was 57 years old with a high percentage of comorbidities and a high Pneumonia Severity Index. Patients with Mycoplasma showed a non significant tendency of being older and having a greater number of comorbidities. In the cases with Streptococcus pneumoniae, a greater percentage of hypotension, severe hypoalbuminemia, compromise of more than one lobe, liver abnormalities and hospitalization in the ICU were observed. The only significant difference was the development of renal failure in patients with Pneumococcus. In the studied population there were no variables which could have a predictive value of the causative agent.

FPGA-based fused smart sensor for real-time plant-transpiration dynamic estimation.

Plant transpiration is considered one of the most important physiological functions because it constitutes the plants evolving adaptation to exchange moisture with a dry atmosphere which can dehydrate or eventually kill the plant. Due to the importance of transpiration, accurate measurement methods are required; therefore, a smart sensor that fuses five primary sensors is proposed which can measure air temperature, leaf temperature, air relative humidity, plant out relative humidity and ambient light. A field programmable gate array based unit is used to perform signal processing algorithms as average decimation and infinite impulse response filters to the primary sensor readings in order to reduce the signal noise and improve its quality. Once the primary sensor readings are filtered, transpiration dynamics such as: transpiration, stomatal conductance, leaf-air-temperature-difference and vapor pressure deficit are calculated in real time by the smart sensor. This permits the user to observe different primary and calculated measurements at the same time and the relationship between these which is very useful in precision agriculture in the detection of abnormal conditions. Finally, transpiration related stress conditions can be detected in real time because of the use of online processing and embedded communications capabilities.

Transient expiratory flow interruptions (TEFI) increase expiratory flow in acute asthma exacerbation.

We have shown that expiratory flows increase when expirations are rapidly interrupted in stable asthmatic patients. We hypothesized that a similar increase could be obtained in patients with acute exacerbation of bronchial asthma treated in the Emergency Room. A total of 30 asthmatic patients were randomly allocated into two groups, the study and the control groups. Patients in the study group were connected to a device with an inspiratory line designed to administer pressurized aerosols. The expiratory line passed through a valve completely interrupting flow at 4 Hz, with an open/closed time ratio of 10/3. The control group patients were also connected to the device, but with the valve kept open. Mean expiratory flow at tidal volume (MEFTV) was measured under basal conditions and at 4, 8 and 12 minutes after connecting the patients to the device. All patients received standard treatment throughout the procedure. At all time points MEFTV increased more in the study than in the control group (p < 0.003 by two-way ANOVA). There was no residual effect after disconnection from the device. We conclude that TEFI can rapidly improve expiratory flows in patients with acute exacerbations of asthma, while pharmacologic interventions proceed.

Transient expiratory flow interruptions (TEFI) increase expiratory flow in acute asthma exacerbation / Incremento del flujo espiratorio luego de interrupciones transitorias en la exacerbación aguda de asma

We have shown that expiratory flows increase when expirations are rapidly interrupted in stable asthmatic patients. We hypothesized that a similar increase could be obtained in patients with acute exacerbation of bronchial asthma treated in the Emergency Room. A total of 30 asthmatic patients were randomly allocated into two groups, the study and the control groups. Patients in the study group were connected to a device with an inspiratory line designed to administer pressurized aerosols. The expiratory line passed through a valve completely interrupting flow at 4 Hz, with an open/closed time ratio of 10/3. The control group patients were also connected to the device, but with the valve kept open. Mean expiratory flow at tidal volume (MEFTV) was measured under basal conditions and at 4, 8 and 12 minutes after connecting the patients to the device. All patients received standard treatment throughout the procedure. At all time points MEFTV increased more in the study than in the control group (p < 0.003 by two-way ANOVA). There was no residual effect after disconnection from the device. We conclude that TEFI can rapidly improve expiratory flows in patients with acute exacerbations of asthma, while pharmacologic interventions proceed.

Demostramos que el flujo espiratorio máximo, en pacientes asmáticos en estado estable, se incrementaba cuando se generaban rápidas y transitorias interrupciones del flujo. Formulamos la hipótesis de que un incremento similar podría ser observado en pacientes con exacerbación aguda de asma tratados en la sala de emergencias. Un total de 30 pacientes asmáticos fueron distribuidos al azar en dos grupos. Los pacientes del grupo en estudio fueron conectados a un aparato con una vía inspiratoria diseñada para la administración de aerosoles. La vía espiratoria pasaba por una válvula que interrumpía el flujo completamente a 4 hz, con una relación tiempo abierta/tiempo cerrada de 10/3. Los pacientes del grupo control también fueron conectados al aparato pero con la válvula siempre abierta. Se midió el flujo medio de la espiración a volumen circulante en condiciones basales y a los 4, 8 y 12 minutos después de conectado el paciente al equipo. Todos los pacientes recibieron el tratamiento farmacológico estándar a lo largo del ensayo. Se observó un incremento significativamente mayor del flujo espiratorio medio a volumen circulante en el grupo en estudio en comparación al grupo control (p < 0.003 ANOVA de dos vías) durante todo el ensayo. No hubo efecto residual después de la desconexión del equipo. Concluimos que las interrupciones transitorias del flujo espiratorio pueden incrementar rápidamente el flujo espiratorio en pacientes con exacerbaciones agudas de asma dando tiempo a que el tratamiento farmacológico comience a actuar.

Comparative study of the resistance of manual and mechanical sutures in the bronchial stump of dogs submitted to left pneumonectomy.

OBJECTIVE: To compare the resistance of manual suture with that of mechanical suture immediately after the suture of the left bronchial stump of dogs submitted to pneumonectomy. METHODS: A total of 15 mixed-breed dogs of both genders, each weighing between 8 and 23 kg, were randomly divided into 2 groups. In group I (n = 7), the bronchial stump was sutured manually (the Sweet method) and, in group II (n = 8), it was stapled. Immediately after the closure of the bronchial stump, the intratracheal pressure was progressively increased in a controlled manner. RESULTS: The mean rupture pressure of the bronchial stump suture line was 33.71 mmHg in group I and 89.87 mmHg in group II (p < 0.01). CONCLUSION: These data allowed us to conclude that mechanical suture of the bronchial stump, submitted to pressure immediately after closure, is more resistant than is manual suture in dogs submitted to pneumonectomy.

Estudo comparativo entre a resistência das suturas manual e mecânica do coto brônquico em cães submetidos a pneumonectomia esquerda / Comparative study of the resistance of manual and mechanical sutures in the bronchial stump of dogs submitted to left pneumonectomy

OBJETIVO: O objetivo do presente trabalho foi comparar a resistência da sutura manual e da sutura mecânica imediatamente após a sutura do coto brônquico esquerdo de cães submetidos a pneumonectomia. MÉTODOS: Foram utilizados 15 cães mestiços, de ambos os sexos, com peso variando entre 8 e 23 kg, distribuídos aleatoriamente em 2 grupos. No grupo I (n = 7), o fechamento do coto brônquico foi realizado com sutura manual (método de Sweet) e, no grupo II, utilizou-se sutura mecânica com grampeador. Imediatamente após o fechamento do coto brônquico, foi provocado aumento da pressão intratraqueal de forma progressiva e controlada. RESULTADOS: A média de pressão de ruptura da linha de sutura do coto brônquico foi 33,71 mmHg no grupo I e 89,87 mmHg no grupo II (p < 0,01). CONCLUSÃO: Esses dados nos permitiram concluir que a sutura mecânica do coto brônquico esquerdo, submetida a pressão imediatamente após a sua realização, apresenta maior resistência que a sutura manual em cães submetidos a pneumonectomia.

OBJECTIVE: To compare the resistance of manual suture with that of mechanical suture immediately after the suture of the left bronchial stump of dogs submitted to pneumonectomy. METHODS: A total of 15 mixed-breed dogs of both genders, each weighing between 8 and 23 kg, were randomly divided into 2 groups. In group I (n = 7), the bronchial stump was sutured manually (the Sweet method) and, in group II (n = 8), it was stapled. Immediately after the closure of the bronchial stump, the intratracheal pressure was progressively increased in a controlled manner. RESULTS: The mean rupture pressure of the bronchial stump suture line was 33.71 mmHg in group I and 89.87 mmHg in group II (p < 0.01). CONCLUSION: These data allowed us to conclude that mechanical suture of the bronchial stump, submitted to pressure immediately after closure, is more resistant than is manual suture in dogs submitted to pneumonectomy.