Existence results for abstract impulsive second-order neutral functional differential equations

We establish the existence of mild solutions for a class of impulsive second-order partial neutral functional differential equations with infinite delay in a Banach space. (C) 2009 Published by Elsevier Ltd

Pseudo-almost periodic solutions for abstract partial functional differential equations

In this work we study the existence and uniqueness of pseudo-almost periodic solutions for a first-order abstract functional differential equation with a linear part dominated by a Hille-Yosida type operator with a non-dense domain. (C) 2009 Published by Elsevier Ltd

On a class of abstract neutral functional differential equations

By using the theory of semigroups of growth a, we discuss the existence of mild solutions for a class of abstract neutral functional differential equations. A concrete application to partial neutral functional differential equations is considered. (C) 2011 Elsevier Ltd. All rights reserved.

Magnetic field effects on the conductivity of organic bipolar and unipolar devices at room temperature

Magnetic field effects on the conductivity of different types of organic devices: undoped and dye doped aluminium (III) 8-hydroxyquinoline (Alq(3))-based organic light emitting diodes (OLEDs), electron-only Alq(3)-based diodes, and a hole-only N,N`-diphenyl-N,N`-bis(1-naphthyl)1,1`-biphenyl-4,4`-diamine (alpha-NPD)-based diode were studied at room temperature. Only negative magnetoresistance (MR) was observed for the Alq(3)-based devices. The addition of a rubrene dye in Alq(3)-based OLEDs quenches the MR by a factor of 5. The alpha-NPD hole-only device showed only positive MR. Our results are discussed with respect to the actual models for MR in organic semiconductors. Our results are in good agreement with the bipolaron model. (C) 2009 Elsevier B.V. All rights reserved.

Endoscopic treatment of Zenker`s diyerticulum by harmonic scalpel

Background: Zenker`s diverticulum (ZD) is a rare condition with a reported prevalence of 0.01% to 0.11% in the general population. Endoscopic treatment consists of the division of the septum between the diverticulum and the esophagus, within which the cricopharyngeal muscle is contained. Diathermic monopolar current, argon plasma coagulation, and laser have been used to incise the muscular septum with satisfactory results. The main limitation of endoscopic treatment is the occurrence of complications. Perforation and hemorrhage are reported in as many as 23% and 10% of patients, respectively. Objective: The aim of this study was to use the technique of endoscopic diverticulotomy by using a harmonic scalpel in patients with ZD and to demonstrate the feasibility of using flexible and rigid devices in ZD treatment. Design: Case series study. Standard protocol was used for patient management, endoscopic procedure, and data collection. Setting: Single endoscopist demonstrating preliminary results. Patients: Five patients (4 men; median standard deviation [SD] age 69.6 +/- 9.06 years, range 59-83 years) with ZD were treated with this technique. All patients reported dysphagia and halitosis. The diagnosis was based on clinical, endoscopic, and radiographic findings. Interventions: All patients received general anesthesia and were placed in the left lateral position. A standard videogastroscope (9.8 mm) and a stiff guidewire were used to insert and achieve an adequate exposure of the ZD septum. The septum was divided using a harmonic scalpel under thin endoscope (5.2 mm) visualization through a soft diverticuloscope. Main Outcome Measurement: Feasibility of an endoscopic technique by using rigid and flexible devices to treat ZD. Results: Four patients (80%) were successfully treated in 1 session. The median SD size of the diverticulum was 3.6 +/- 0.89 cm (range 3-5 cm). Median SD procedure time was 17.33 +/- 2.33 minutes (range 15-20 minutes) in 6 procedures. No hemorrhage or perforation occurred. One patient (20%) required a second session to complete dissection of the ZD septum. All patients demonstrated improvement of dysphagia score after treatment. Limitations: Small case series design. Conclusions: Endoscopic treatment of ZD by harmonic scalpel through a soft diverticuloscope was feasible and effective in this small case series. Larger studies are warranted to further evaluate this technique.

Reprocessing and reuse of single-use medical devices used during hemodynamic procedures in Brazil: A widespread and largely overlooked problem

Background. Several medical devices used during hemodynamic procedures, particularly angiographic diagnostic and therapeutic cardiac catheters, are manufactured for single use only. However, reprocessing and reuse of these devices has been reported, to determine the frequency of reuse and reprocessing of single-use medical devices used during hemodynamic procedures in Brazil and to evaluate how reprocessing is performed. Design. National survey, conducted from December 1999 to July 2001. Methods. Most of the institutions affiliated with the Brazilian Society of Hemodynamic and Interventional Cardiology were surveyed by use of a questionnaire sent in the mail. Results. The questionnaire response rate was 50% (119 of 240 institutions). Of the 119 institutions that responded, 116 (97%) reported reuse of single-use devices used during hemodynamic procedures, and only 26 (22%) reported use of a standardized reprocessing protocol. Cleaning, flushing, rinsing, drying, sterilizing and packaging methods varied greatly and were mostly inadequate. Criteria for discarding reused devices varied widely. Of the 119 institutions that responded, 80 (67%) reported having a surveillance system for adverse events associated with the reuse of medical devices, although most of these institutions did not routinely review the data, and only 38 (32%) described a training program for the personnel who reprocessed single-use devices. Conclusions. The reuse of single-use devices used during hemodynamic procedures was very frequent in hospitals in Brazil. Basic guidance on how to reuse and reprocess single-use medical devices is urgently needed, because, despite the lack of studies to support reusing and reprocessing single-use medical devices, such devices are necessary in limited-resource areas in which these practices are current.

Biofilm formation on intrauterine devices in patients with recurrent vulvovaginal candidiasis

A biofilm is a complex community of surface-associated cells enclosed in a polymer matrix. They attach to solid surfaces and their formation can be affected by growth conditions and co-infection with other pathogens. The presence of biofilm may protect the microorganisms from host defenses, as well as significantly reduce their susceptibility to antifungal agents. Pathogenic microbes can form biofilms on the inert surfaces of implanted devices such as catheters, prosthetic cardiac valves and intrauterine devices (IUDs). The present study was carried out to analyze the presence of biofilm on the surface of intrauterine devices in patients with recurrent vulvovaginal candidiasis, and to determine the susceptibility profile of the isolated yeasts to amphotericin B and fluconazole. Candida albicans was recovered from the IUDs and it was found to be susceptible to the antifungal agents when tested under planktonic growing conditions. These findings indicate the presence of the biofilm on the surface of the IUD as an important risk factor for recurrent vulvovaginal candidiasis.

The frontal assessment battery (FAB) reveals neurocognitive dysfunction in substance-dependent individuals in distinct executive domains: Abstract reasoning, motor programming, and cognitive flexibility

Substance-dependence is highly associated with executive cognitive function (ECF) impairments. However. considering that it is difficult to assess ECF clinically, the aim of the present study was to examine the feasibility of a brief neuropsychological tool (the Frontal Assessment Battery FAB) to detect specific ECF impairments in a sample of substance-dependent individuals (SDI). Sixty-two subjects participated in this study. Thirty DSM-IV-diagnosed SDI, after 2 weeks of abstinence, and 32 healthy individuals (control group) were evaluated with FAD and other ECF-related tasks: digits forward (DF), digits backward (DB), Stroop Color Word Test (SCWT), and Wisconsin Card Sorting Test (WCST). SDI did not differ from the control group on sociodemographic variables or IQ. However, SDI performed below the controls in OF, DB, and FAB. The SDI were cognitively impaired in 3 of the 6 cognitive domains assessed by the FAB: abstract reasoning, motor programming, and cognitive flexibility. The FAB correlated with DF, SCWT, and WCST. In addition, some neuropsychological measures were correlated with the amount of alcohol, cannabis, and cocaine use. In conclusion, SDI performed more poorly than the comparison group on the FAB and the FAB`s results were associated with other ECF-related tasks. The results suggested a negative impact of alcohol, cannabis, and cocaine use on the ECF. The FAB may be useful in assisting professionals as an instrument to screen for ECF-related deficits in SDI. (C) 2010 Elsevier Ltd. All rights reserved.

A new large-caliber trocar for percutaneous endoscopic gastrostomy by the introducer technique in head and neck cancer patients

Background and study aims In many patients, percutaneous endoscopic gastrostomy (PEG) can be limited by digestive tract stenosis. PEG placement using an introducer is the safest alternative for this group of patients, but the available devices are difficult to implement and require smaller-caliber tubes. The aim of this study was to evaluate the modification of an introducer technique device for PEG placement with regard to the following: procedure feasibility, possibility of using a 20-Fr balloon gastrostomy tube, tube-related function and problems, complications, procedure safety, and mortality. Patients and methods Between March 2007 and February 2008, 30 consecutive patients with head and neck malignancies underwent introducer PEG placement with the modified device and gastropexy. Each patient was evaluated for 60 days after the procedure for the success of the procedure, infection, pain, complications, mortality, and problems with the procedure. Results The procedure was successful in all cases with no perioperative complications. No signs of stomal infection were observed using the combined infection score. The majority of patients experienced mild-to-moderate pain both in the immediate postoperative period and at 72 hours. One major early complication (3.3%) and two minor complications (6.7%) were observed. No procedure-related deaths occurred during the first 60 days after the procedure. Conclusion The device modification for PEG using the introducer technique is feasible, safe, and efficient in outpatients with obstructive head and neck cancer. In this series, it allowed the use of a larger-caliber tube with low complication rates and no procedure-related mortality.

Pop-rock musicians: Assessment of their satisfaction provided by hearing protectors

Pop-rock musicians are at risk of developing hearing loss and other symptoms related to amplified music. Aim: The aim of the present study was to assess the satisfaction provided by the use of hearing protection in pop-rock musicians. Study design: Contemporary cohort study. Materials and Methods: A study of 23 male pop-rock musicians, aged between 25 to 45 years. After audiological evaluation (pure tone audiometry, middle ear analysis, TEOAE and DPOAE) hearing protective devices were provided to be used for three months. After that musicians answered a satisfaction assessment questionnaire. Results: The prevalence of hearing loss was of 21.7%. The most common complaints about the hearing protectors were: autophonia, pressure in the ears, interference in high frequencies perception and full time use of the hearing protector during concerts. There was a positive correlation between a reduction in tinnitus after the use of the HPD with the following complaints: tinnitus after beginning the career (p=0.044), discomfort with the sound intensity in the work place (p=0.009) and intolerance to loud sound (p=0.029). Conclusions: There was a high prevalence of hearing loss and a positive tendency towards the use of the ear protector device among the sample population.

Prevention of Venous Thrombosis by Warfarin after Permanent Transvenous Leads Implantation in High-Risk Patients

Background: The incidence of venous lesions following transvenous cardiac device implantation is high. Previous implantation of temporary leads ipsilateral to the permanent devices, and a depressed left ventricular ejection fraction have been associated with an increased risk of venous lesions, though the effects of preventive strategies remain controversial. This randomized trial examined the effects of warfarin in the prevention of these complications in high-risk patients. Method: Between February 2004 and September 2007, we studied 101 adults who underwent a first cardiac device implantation, and who had a left ventricular ejection fraction <= 0.40, or a temporary pacing system ipsilateral to the permanent implant, or both. After device implantation, the patients were randomly assigned to warfarin to a target international normalized ratio of 2.0-3.5, or to placebo. Clinical and laboratory evaluations were performed regularly up to 6 months postimplant. Venous lesions were detected at 6 months by digital subtraction venography. Results: Venous obstructions of various degrees were observed in 46 of the 92 patients (50.0%) who underwent venography. The frequency of venous obstructions was 60.4% in the placebo, versus 38.6% in the warfarin group (P = 0.018), corresponding to an absolute risk reduction of 22% (relative risk = 0.63; 95% confidence interval = 0.013-0.42). Conclusions: Warfarin prophylaxis lowered the frequency of venous lesions after transvenous devices implantation in high-risk patients. (PACE 2009; 32:S247-S251)

UTERINE ULTRASONOGRAPHIC CHANGES DURING ENDOMETRIOSIS TREATMENT: A COMPARISON BETWEEN LEVONORGESTREL-RELEASING INTRAUTERINE DEVICES AND A GONADOTROPIN-RELEASING HORMONE AGONIST

We compared the effects of levonorgestrel-releasing intrauterine devices (LNG-IUD) and a gonadotropin-releasing hormone agonist (GnRHa) on uterine volume, uterine arteries pulsatility index (PI) and endometrial thickness before and after six months of endometriosis treatment. Sixty women aged 18-40 y were allocated randomly to one of two groups: LNG-IUDs were inserted in 30 women, and GnRHa monthly injections were performed on the other 30. All 60 women were submitted to transvaginal 2-D ultrasound scans on the day that the treatment started and then six months later. Measurements of uterine arteries PI, uterine volume and endometrial thickness were performed at both evaluations. The use of LNG-IUDs significantly decreased endometrial thickness (pre = 6.08 +/- 3.00 mm, post = 2.7 +/- 0.98 mm; mean +/- SD), as did the use of GnRHa (pre = 6.96 +/- 3.82 mm, post = 3.23 +/- 2.32 mm). The uterine volume decreased in the GnRHa group (pre = 86.67 +/- 28.38 cm(3), Post = 55.27 +/- 25.52 cm(3)), but not in the LNG-IUD group (pre = 75.77 +/- 20.88 cm(3), post = 75.97 +/- 26.62 cm(3)). Uterine arteries PI increased for both groups; however, the increase was higher in the GnRHa group (0.99 +/- 0.84 vs. 0.38 +/- 0.84, p = 0.007; PI increase in GnRHa and in LNG-IUD groups, respectively). In conclusion, levonorgestrel released directly onto the endometrium by the LNG-IUD induced smaller uterine changes than did the hypoestrogenism induced by GnRHa. Nevertheless, both promoted similar effects on endometrial thickness. (E-mail: wpmartins@gmail.com) (C) 2008 World Federation for Ultrasound in Medicine & Biology.

Effects of intrapulpal temperature change induced by visible light units on the metabolism of odontoblast-like cells

Purpose: To investigate the effects of intrapulpal temperature changes induced by a quartz tungsten halogen (QTH) and a light emitting diode (LED) curing units on the metabolism of odontoblast-like cells. Methods: Thirty-six 0.5 mm-thick dentin discs obtained from sound human teeth were randomly assigned into three groups: QTH, LED and no light (control). After placement of the dentin discs in pulp chamber devices, a thermistor was attached to the pulpal surface of each disc and the light sources were applied on the occlusal surface. After registering the temperature change, odontoblast-like cells MDPC-23 were seeded on the pulpal side of the discs and the curing lights were again applied. Cell metabolism was evaluated by the MTT assay and cell morphology was assessed by SEM. Results: In groups QTH and LED the intrapulpal temperature increased by 6.4 degrees C and 3.4 degrees C, respectively. The difference between both groups was statistically significant (Mann-Whitney; P< 0.05). QTH and LED reduced the cell metabolism by 36.4% and 33.4%, respectively. Regarding the cell metabolism, no statistically significant difference was observed between both groups (Mann-Whitney; P> 0.05). However, when compared to the control, only QTH significantly reduced the cell metabolism (Mann-Whitney; P< 0.05). It was concluded that the irradiance of 0.5 mm-thick human dentin discs with a QTH in comparison to a LED curing unit promoted a higher temperature rise, which propagates through the dentin negatively affecting the metabolism of the underlying cultured pulp cells. (Am J Dent 2009;22:151-156).

Temperature safety profile of laparoscopic devices: Harmonic ACE (ACE), Ligasure V (LV), and plasma trisector (PT)

Background Reports of iatrogenic thermal injuries during laparoscopic surgery using new generation vessel-sealing devices, as well as anecdotal reports of hand burn injuries during hand-assisted surgeries, have evoked questions about the temperature safety profile and the cooling properties of these instruments. Methods This study involved video recording of temperatures generated by different instruments (Harmonic ACE [ACE], Ligasure V [LV], and plasma trisector [PT]) applied according the manufacturers` pre-set settings (ACE setting 3; LV 3 bars, and the PT TR2 50W). The video camera used was the infrared Flex Cam Pro directed to three different types of swine tissue: (1) peritoneum (P), (2) mesenteric vessels (MV), and (3) liver (L). Activation and cooling temperature and time were measured for each instrument. Results The ACE device produced the highest temperatures (195.9 degrees +/- 14.5 degrees C) when applied against the peritoneum, and they were significantly higher than the other instruments (LV = 96.4 degrees +/- 4.1 degrees C, and PT = 87 degrees +/- 2.2 degrees C). The LV and PT consistently yielded temperatures that were < 100 degrees C independent of type of tissue or ""on""/ ""off"" mode. Conversely, the ACE reached temperatures higher than 200 degrees C, with a surprising surge after the instrument was deactivated. Moreover, temperatures were lower when the ACE was applied against thicker tissue (liver). The LV and PT cooling times were virtually equivalent, but the ACE required almost twice as long to cool. Conclusions The ACE increased the peak temperature after deactivation when applied against thick tissue (liver), and the other instruments inconsistently increased peak temperatures after they were turned off, requiring few seconds to cool down. Moreover, the ACE generated very high temperatures (234.5 degrees C) that could harm adjacent tissue or the surgeon`s hand on contact immediately after deactivation. With judicious use, burn injury from these instruments can be prevented during laparoscopic procedures. Because of the high temperatures generated by the ACE device, particular care should be taken when it is used during laparoscopy.

An ex vivo comparison of root canal length determination by three electronic apex locators at positions short of the apical foramen

Objective. The aim of this study was to evaluate the precision of working length determination of 3 electronic apex locators (EALs): Root ZX, RomiApex D-30, and Ipex at 0.0 mm, at the apical foramen (AF), and at 1.0 mm short of the AF. Methodology. Thirty-eight mandibular premolars had their real lengths previously determined. Electronic measurements were determined at 1.0 mm, followed by measurements at 0.0 mm, performed in triplicate. Results. Precision of devices at 1.0 mm and 0.0 mm were: 94.7% and 97.4%, respectively (Root ZX); 78.9% and 97.4% (RomiApex D-30); and 76.3% and 97.4% (Ipex). Although no statistical differences were observed between the EALs at 0.0, at 1.0 mm Root ZX performed significantly better than the others. Conclusion. The EALs had acceptable precision when measuring the working length at the AF. However, when used at levels short of the AF, only Root ZX did not suffer a significant negative effect on precision. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010;110:e57-e61)