A high efficiency HPF-ZCS-PWM Sepic for electronic ballast with multiple tubular fluorescent lamps

This paper presents a high efficiency Sepic rectifier for an electronic ballast application with multiple fluorescent lamps. The proposed Sepic rectifier is based on a Zero-Current-Switching (ZCS) Pulse-Width-Modulated (PWM) soft-commutation cell. The high power-factor of this structure is obtained using the instantaneous average-current control technique, in order to attend properly IEC61000-3-2 standards. The inverting stage of this new electronic ballast is a classical Zero-Voltage-Switching (ZVS) Half-Bridge inverter. A proper design methodology is developed for this new electronic ballast, and a design example is presented for an application with five fluorescent lamps 40W-T12 (200W output power), 220Vrms input voltage, 130Vdc dc link voltage, with rectifier and inverter stages operating at 50kHz. Experimental results are also presented. The THD at input current is equal to 6.41%, for an input voltage THD equal to 2.14%, and the measured overall efficiency is about 92.8%, at rated load.

Effects of contrast material on computed tomographic measurements of lung volumes in patients with acute lung injury

Background. Intravenous injection of contrast material is routinely performed in order to differentiate nonaerated lung parenchyma from pleural effusion in critically ill patients undergoing thoracic computed tomography (CT). The aim of the present study was to evaluate the effects of contrast material on CT measurement of lung volumes in 14 patients with acute lung injury. Method. A spiral thoracic CT scan, consisting of contiguous axial sections of 10 mm thickness, was performed from the apex to the diaphragm at end-expiration both before and 30 s (group 1; n=7) or 15 min (group 2; n=7) after injection of 80 ml contrast material. Volumes of gas and tissue, and volumic distribution of CT attenuations were measured before and after injection using specially designed software (Lungview®; Institut National des Télécommunications, Evry, France). The maximal artifactual increase in lung tissue resulting from a hypothetical leakage within the lung of the 80 ml contrast material was calculated. Results. Injection of contrast material significantly increased the apparent volume of lung tissue by 83 ± 57 ml in group 1 and 102 ± 80 ml in group 2, whereas the corresponding maximal artifactual increases in lung tissue were 42 ± 52 ml and 31 ± 18 ml. Conclusion. Because systematic injection of contrast material increases the amount of extravascular lung water in patients with acute lung injury, it seems prudent to avoid this procedure in critically ill patients undergoing a thoracic CT scan and to reserve its use for specific indications.

Spectrophotometric flow-injection determination of sulphite in white wines involving gas diffusion through a concentric tubular membrane

A flow-injection system is proposed for the spectrophotometric determination of sulphite in white wines. The method involves analyte conversion to SO2, gas diffusion through a Teflon® semi-permeable membrane, collection into an alkaline stream (pH 8), reaction with Malachite green (MG) and monitoring at 620 nm. With a concentric tubular membrane, the system design was simplified. Influence of reagent concentrations, pH of donor and acceptor streams, temperature, timing, surfactant addition and presence of potential interfering species of the wine matrix were investigated. A pronounced (ca. 100%) enhancement in sensitivity was noted by adding cetylpyridinium chloride (CPC). The proposed system is robust and baseline drift is not observed during 4 h operating periods. Only 400 μL of sample and 0.32 mg MG are required per determination. The system handles 30 samples per hour, yielding precise results (r.s.d. < 0.015 for 1.0 - 20.0 mg L-1 SO2) in agreement with those obtained by an alternative procedure.

Immune regulatory effect of pHSP65 DNA therapy in pulmonary tuberculosis: Activation of CD8+ cells, interferon-γ recovery and reduction of lung injury

A DNA vaccine based on the heat-shock protein 65 Mycobacterium leprae gene (pHSP65) presented a prophylactic and therapeutic effect in an experimental model of tuberculosis. In this paper, we addressed the question of which protective mechanisms are activated in Mycobacterium tuberculosis-infected mice after immune therapy with pHSP65. We evaluated activation of the cellular immune response in the lungs of infected mice 30 days after infection (initiation of immune therapy) and in those of uninfected mice. After 70 days (end of immune therapy), the immune responses of infected untreated mice, infected pHSP65-treated mice and infected pCDNA3-treated mice were also evaluated. Our results show that the most significant effect of pHSP65 was the stimulation of CD8+ lung cell activation, interferon-γ recovery and reduction of lung injury. There was also partial restoration of the production of tumour necrosis factor-α. Treatment with pcDNA3 vector also induced an immune stimulatory effect. However, only infected pHSP65-treated mice were able to produce significant levels of interferon-γ and to restrict the growth of bacilli.

Dimmable electronic ballast with high power-factor SEPIC preregulator, for multiple tubular fluorescent lamps

An electronic ballast for multiple tubular fluorescent lamps is presented in this paper. The proposed structure features high power-factor, dimming capability, and soft-switching to the semiconductor devices operated in high frequencies. A Zero-Current-Switching - Pulse-Width-Modulated (ZCS-PWM) SEPIC converter composes the rectifying stage, controlled by the instantaneous average input current technique, performing soft-commutations and high input power factor. Regarding the inverting stage, it is composed by a classical resonant Half-Bridge converter, associated to Series Parallel-Loaded Resonant (SPLR) filters. The dimming control technique employed in this Half-Bridge inverter is based on the phase-shift in the current processed through the sets of filter + lamp. In addition, experimental results are shown in order to validate the developed analysis.

Proposal of a new technique for bile duct reconstruction after iatrogenic injury. Study in dogs and review of the literature

Purpose: Interposition of a jejunal tube between the common bile duct and duodenum. Methods: Five adult mongrel dogs of both sexes, weighing on average 22.3 kg (18 to 26.5 kg), were used. Obstructive jaundice was induced by ligation of the distal common bile duct. After one week, a 2.5-cm long jejunal tube was fabricated from a segment of the loop removed 15 cm from the Treitz angle and interposed between the common bile duct and duodenum. Results: The animals presented good clinical evolution and no complications were observed. After 6 weeks, complete integration was noted between the bile duct mucosa, tube and duodenum and a significant reduction in total bilirubin and alkaline phosphatase was observed when compared to the values obtained one week after ligation of the common bile duct. Conclusion: The jejunal tube interposed between the dilated bile duct and duodenum showed good anatomic integration and reduced total bilirubin and alkaline phosphatase levels in the animals studied.

Endovascular treatment of pseudoaneurysm of the thoracic aorta from a firearm injury

A 24-year-old male patient was the victim of a firearm wound that penetrated the thorax. He arrived at another hospital hemodynamically unstable and was submitted to exploratory surgery by means of bithoracotomy. A lesion of the left branch of the pulmonary artery was detected and successfully repaired. He was submitted for computer-aided tomography on the fifth postoperative day, and a lesion of the mid-thoracic aorta was detected, which formed a saccular image. Considering that the patient had already been submitted to a bithoracotomy and that a direct approach to repair would involve another thoracotomy within a short period of time, endovascular treatment was chosen in our hospital. The procedure was performed under fluoroscopy. A second computer-aided tomography indicated adequate treatment of the lesion, with no indication of an endoleak. He has undergone ambulatory follow-up for 36 months without any problem related to the procedure. While endovascular treatment of the aorta has developed enormously, multicenter studies are needed to better define the long-term results of this approach. © 2008 Published by European Association for Cardio-Thoracic Surgery. All rights reserved.

Dental trauma involving root fracture and periodontal ligament injury: A 10-year retrospective study

The purpose of this retrospective study was to analyze the cases of traumatic dental injuries involving root fracture and/or periodontal ligament injury (except avulsion) treated at the Discipline of Integrated Clinic, School of Dentistry of Araçatuba, São Paulo State University (UNESP), Brazil, from January 1992 to December 2002. Clinical and radiographic records from 161 patients with 287 traumatized teeth that had sustained root fracture and/or injuries to the periodontal ligament were examined. The results of this survey revealed that subluxation (25.09%) was the most common type of periodontal ligament injury, followed by extrusive luxation (19.86%). There was a predominance of young male patients and most of them did not present systemic alterations. Among the etiologic factors, the most frequent causes were falls and bicycle accidents. Injuries on extraoral soft tissues were mostly laceration and abrasion, while gingival and lip mucosa lacerations prevailed on intraoral soft tissues injuries. Radiographically, the most common finding was an increase of the periodontal ligament space. The most commonly performed treatment was root canal therapy. Within the limits of this study, it can be concluded that traumatic dental injuries occur more frequently in young male individuals, due to falls and bicycle accidents. Subluxation was the most common type of periodontal ligament injury. Root canal therapy was the type of treatment most commonly planned and performed.

Amifostine reduces the seminiferous epithelium damage in doxorubicin-treated prepubertal rats without improving the fertility status

Background: Amifostine is an efficient cytoprotector against toxicity caused by some chemotherapeutic drugs. Doxorubicin, a potent anticancer anthracycline, is known to produce spermatogenic damage even in low doses. Although some studies have suggested that amifostine does not confer protection to doxorubicin-induced testicular damage, schedules and age of treatment have different approach depending on the protocol. Thus, we proposed to investigate the potential cytoprotective action of amifostine against the damage provoked by doxorubicin to prepubertal rat testes (30-day-old) by assessing some macro and microscopic morphometric parameters 15, 30 and 60 days after the treatment; for fertility evaluation, quantitative analyses of sperm parameters and reproductive competence in the adult phase were also carried out.Methods: Thirty-day-old male rats were distributed into four groups: Doxorubicin (5 mg/kg), Amifostine (400 mg/kg), Amifostine/Doxorubicin (amifostine 15 minutes before doxorubicin) and Sham Control (0.9% saline solution). Standard One Way Anova parametric and Anova on Ranks non-parametric tests were applied according to the behavior of the obtained data; significant differences were considered when p < 0.05.Results: The rats killed 30 and 60 days after doxorubicin treatment showed diminution of seminiferous epithelium height and reduction on the frequency of tubular sections containing at least one type of differentiated spermatogonia; reduction of sperm concentration and motility and an increase of sperm anomalous forms where observed in doxorubicin-treated animals. All these parameters were improved in the Amifostine/Doxorubicin group only when compared to Doxorubicin group. Such reduction, however, still remained below the values obtained from the Sham Control group. Nevertheless, the reproductive competence of doxorubicin-treated rats was not improved by amifostine pre-administration.Conclusions: These results suggest that amifostine promotes a significant reduction of the doxorubicin long-term side effects on the seminiferous epithelium of prepubertal rats, which is reflected in the epidydimal fluid parameters in the adult phase. However, fertility status results suggest that such protection may not be effective against sperm DNA content damage. Further investigation of sperm DNA integrity must be carried out using amifostine and doxorubicin-treated experimental models. © 2010 Vendramini et al; licensee BioMed Central Ltd.

Template-based fluoropolymer ferroelectrets with multiple layers of tubular channels

Significant efforts are devoted to developing new ferroelectrets with well-controlled void distributions or uniform voids and with good long-term and thermal stability of the piezoelectricity. Here, we describe the concept, the fabrication, and the most relevant properties of fluoropolymer ferroelectret systems with three separate films of fluoroethylenepropylene (FEP), alternating with two polytetrafluoroethylene (PTFE) templates. The FEP films are selectively fused by means of a lamination process. Two practically identical PTFE templates are used, which have parallel rectangular openings (1.5×30 mm 2) separated by PTFE ridges of 1.5 mm width. After removing the PTFE templates, a three-layer FEP-film sandwich with tubular channels is obtained. We demonstrate that such FEP-film systems exhibit significant and stable piezoelectricity after charging under a high DC voltage. The resulting piezoelectric effect may be further improved by carefully assembling and arranging the PTFE templates during preparation. ©2010 IEEE.

Orbitoethmoidal impacted injury by kitchen knife causing abducens nerve palsy

Introduction: Impacted knife injuries in the maxillofacial region are rare and infrequently reported. In cases of injury involving orbit or eye, these reports are even rarer. Discussion: Damage to the orbital contents may result in a rupture of the globe, extraocular muscle injury, lacrimal gland damage, and others. Orbital foreign bodies are not only difficult to detect, and clinical features vary according to its size, characteristics, shape, penetrating method, and site. In this report, a case of abducens nerve palsy after orbitoethmoidal knife injury is presented. © 2010 Springer-Verlag.

Different prescribed doses of high-volume peritoneal dialysis and outcome of patients with acute kidney injury.

The optimal dialysis dose for the treatment of acute kidney injury (AKI) is controversial. No studies have directly examined the effects of peritoneal dialysis (PD) dose on outcomes in AKI. From January 2005 to January 2007, we randomly assigned critically ill patients with AKI to receive higher- or lower-intensity PD therapy (prescribed Kt/Vof 0.8 and 0.5 per session respectively). The main outcome measure was death within 30 days. Of the 61 enrolled patients, 30 were randomly assigned to higher-intensity therapy, and 31, to a lower-intensity PD dose. The two study groups had similar baseline characteristics and received treatment for 6.1 days and 5.7 days respectively (p = 0.42). At 30 days after randomization, 17 deaths had occurred in the higher-intensity group (55%), and 16 deaths, in the lower-intensity group (53%, p = 0.83). There was a significant difference between the groups in the PD dose prescribed compared with the dose delivered (higher-intensity group: 0.8 vs. 0.59, p = 0.04; lower-intensity group: 0.5 vs. 0.49, p = 0.89). The groups had similar metabolic control after 4 PD sessions (blood urea nitrogen: 69.3 +/- 14.4 mg/dL and 60.3 +/- 11.1 mg/dL respectively, p = 0. 71). In critically ill patients with AKI, an intensive PD dose did not lower the mortality or improve the recovery of kidney function or metabolic control. The PD dose is limited by dialysate flow and membrane permeability, and clearance per exchange can decrease if a shorter dwell time is applied.

Occurrence of traumatic dental injury in cases of domestic violence

The purpose of this study was to investigate the prevalence and types of traumatic dental injuries in situations of domestic violence. A coross-sectional study was conducted and data were collected from the police occurrence records to domestic physical aggression between 2001 and 2005. Of the 1,844 subjects who underwent medical evaluation, 15 had information pertaining to traumatic dental injuries. From the medical records, the forensic medical reports completed by the forensic medical experts who examined the victims after the aggression were reviewed and data of individuals with dental injuries (e.g., fractures, luxation and avulsion) were collected. In the selected sample, there was a predominance of individuals with injuries to the head and neck region (38.7%), and the frequency of traumatic dental injuries among all injuries to the head and neck region was 2.0%. The most frequently injured teeth were the maxillary incisors (31.8%), followed by the mandibular incisors (27.3%) and the maxillary canines (9.1%). In 31.8% of the injured teeth, the forensic experts did not specify the nomenclature. Of the dental trauma cases, 59.1% were fractures, 27.2% were luxations and 13.7% were avulsions. In conclusion, domestic violence was an important etiologic factor of traumatic dental injury. The aggression in all cases occurred in the form of punches and slaps. Fracture was the most common type of traumatic dental injury, and the most frequently injured teeth were the incisors.

Long-term outcome of patients followed by nephrologists after an acute tubular necrosis episode

Aims of our study were to describe the long-term survival in patients surviving an acute tubular necrosis (ATN) episode and determine factors associated with late mortality. We performed a prospective cohort study that evaluated the long-term outcome of 212 patients surviving an ATN episode. Mortality at the end of followup was 24.5%, and the probability of these patients being alive 5 years after discharge was 55%. During the followup, 4.7% of patients needed chronic dialysis. Univariate analysis showed that previous CKD (P = 0.0079), cardiovascular disease (P = 0.019), age greater than 60 years (P < 0.0001), and higher SCr baseline (P = 0.001), after 12 months (P = 0.0015) and 36 months (P = 0.004), were predictors of long-term mortality. In multivariate analysis, older age (HR = 6.4, CI 95% = 1.2-34.5, P = 0.02) and higher SCr after 12 months (HR = 2.1, 95% CI 95% = 1.14-4.1, P = 0.017) were identified as risk factors associated with late mortality. In conclusion, 55% of patients surviving an ATN episode were still alive, and less than 5% required chronic dialysis 60 months later; older age and increased Scr after 12 months were identified as risk factors associated with late death. © 2012 G. A. Brito et al.