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This paper explores the extent to which pre-buckling of layers (in thin film multilayered structures) can be used to increase the flexibility of organic electronic devices. The deformation of wavy/buckle profiles, with a range of nano- and micro-scale wavelengths, is modeled using finite element simulations. The predictions from the models are then validated using experiments that involve the bending of layered structures that are relevant to flexible organic electronics. The introduction of pre-buckled profiles is shown to increase the range of deformation that is applied to model structures, prior to onset of significant stresses and strains. The implications of the work are discussed for the design of robust flexible organic solar cells. [ABSTRACT FROM AUTHOR]

Background: This prospective, controlled experimental study was planned to investigate the effects of levosimendan on transforming growth factor (TGF)-beta3 and Smad1, Smad2 and Smad3 expression in the early stages of sepsis., Methods: Twenty-four rats were randomized into four groups: (1) sham-operated controls, (2) dobutamine group--subjected to abdominal hypertension and peritonitis-induced sepsis using cecal ligation and puncture (CLP), then treated with 10 microg x kg(-1) min(-1) intravenous (IV) dobutamine infusion, (3) levosimendan group--as in 2, then treated with levosimendan IV bolus 200 microg x kg(-1) followed by 200 microg x kq(-1) min(-1) IV infusion, and (4) a control group as in 2, with no treatment. All rats were killed 8 hours after CLP. Aorta tissue samples were analyzed by immunohistochemical staining., Results: CLP caused mild interleukin (IL)-1 immunostaining in both control and dobutamine groups. Immunoreactivity of tumor necrosis factor (TNF)-alpha was mild in both sham and control groups. TGF-beta3 immunostaining was mildly increased in groups sham, control and dobutamine, whereas it was found moderate in group levosimendan. Smad1, Smad2 and Smad3 were found moderately increased only in group levosimendan., Conclusion: Beneficial effects of levosimendan on hemodynamics and global oxygen transport were reported in experimental and clinical trials. Besides its potency on C++ ion sensitivity, it should influence inflammatory cytokine production by diminishing TGF-beta3 and Smad1, Smad2 and Smad3 expression.

Purpose: This study aimed to investigate the apoptotic mechanisms, oxidative stress, and mechanisms of effect of antibiotics and ursodeoxycholic acid (UDCA) in total parenteral nutrition (TPN)-associated liver injury., Methods: Four groups of young rabbits were used in the study as follows: Group 1 (n: 7): TPN + Metronidazole (30 mg/kg IV) + Gentamicin (6 mg/kg IV); Group 2 (n: 7): TPN + UDCA (15 mg/kg per oral); Group 3 (n: 6): TPN only; and Group 4 (n: 7): Control group. After 10 days, the animals were killed and livers were removed. Hepatic apoptosis, apoptotic proteins, malondialdehyde (MDA) and myeloperoxidase (MPO) levels were studied in liver, and direct bilirubin values were assessed in the blood samples., Results: Direct bilirubin increased with TPN, and antibiotic combination, as the most effective group, significantly lowered its levels (p < 0.01). MDA values also showed significant differences in comparisons between G1 and G3 (p < 0.05) and G1-G4 (p < 0.01). An increased number of apoptotic cells was detected particularly in G2 and G3, whereas the lowest levels, other than in the control group, were found in G1. All TUNEL-positive cell number data were statistically significant except between G2 and G3(p < 0.05). Caspase-3 and Bax immunoreactivities were greatest in G2. Significant differences were shown in caspase-3 immunoreactivity between the groups (p < 0.01), except between G1 and G3 (p > 0.05). All comparisons between the groups were significant for Bax (p < 0.01). In contrast, Bcl-2 immunoreactivity was moderate and highest in G1: comparisons between G1 and the other groups demonstrated statistically significant differences (p < 0.01). Fas-L immunoreactivity was greatest in G2, and all comparisons between the groups were statistically significant (p < 0.01)., Conclusions: Metronidazole and gentamicin combination is effective on TPN-induced liver injury by the Bcl-2 anti-apoptotic pathway, total anti-apoptotic effect and by decreasing bilirubin levels. Oxidative injury in the liver increased with therapy. UDCA seems less effective on TPN-associated liver injury.

The effects of levosimendan on acute lung injury induced by peritonitis and abdominal hypertension in the early stages of sepsis in rats were investigated. Twenty-four adult male Wistar rats were randomized into: (1) sham, (2) subjected to abdominal hypertension and peritonitis induced lung injury using cecal ligation and puncture, then treated by dobutamine, (3) subjected to abdominal hypertension and peritonitis induced lung injury using cecal ligation and puncture, then treated by levosimendan, and (4) controls subjected to abdominal hypertension and peritonitis induced lung injury using cecal ligation and puncture with no treatment. In the control and levosimendan groups, cecal ligation and puncture resulted in moderate IL-1beta immunolabelling in lung tissue; marked IL-1beta immunolabelling was demonstrated in the dobutamine group. TNF-alpha immunolabelling was negative in both the sham and levosimendan groups, but moderate and weak immunoreactivities were observed in the dobutamine and control groups, respectively. There were almost no TUNEL positive cells in the sham, but they were prominent in the control. TUNEL positive cells were significantly less in the levosimendan treated lungs when compared to control and dobutamine groups. Immunoreactivity of eNOS was stronger in the dobutamine group when compared with the levosimendan group. In addition, iNOS immunoreactivity was strongly detected in the control group; this immunoreactivity was less in the levosimendan group than the dobutamine group. In this experimental sepsis model, treatment with levosimendan had a marked effect on attenuating or decreasing apoptosis and inflammation in the lung.

The purpose of this in vitro study was to observe the morphological changes and apical dye penetration at apical dentin surfaces after apicoectomy with conventional techniques and laser beam. Sixty single-rooted extracted teeth were selected for the study. The crowns were resected below the cemento-enamel junction. Then, these teeth were treated endodontically and filled with gutta-percha using AH-26 root canal sealer. The teeth were randomly divided into four groups of 15 teeth in each. The roots were resected perpendicular to its long axis 3 mm from the apex using Er: yttrium-aluminium-garnet (YAG) laser irradiation in groups 1 and 2, and the resected root surfaces were lased with Nd:YAG laser in group 2. The apexes were resected by a high-speed handpiece in groups 3 and 4, and the resected root surfaces were lased with Nd:YAG laser in group 4. Ten teeth in each group were used for leakage studies, and the other five teeth were used for scanning electron microscopic examinations. Seven sections were obtained from each root to assess the microleakage, and the sections were analyzed in a computer-assisted manner. No statistically significant differences were observed between the leakage percentage of groups 1 and 3 and groups 2 and 4 (p>0.05). Morphological differences were observed between apical dentin surfaces resected with conventional techniques and laser beam.

Purpose: To study the blood flow patterns of utero-ovarian circulation in polycystic ovary syndrome (PCOS) and to assess their relationship with clinical, metabolic, and hormonal data., Methods: Forty-three women with PCOS and 43 age-matched healthy controls underwent Doppler examination of the utero-ovarian circulation in the follicular phase. Demographic, hormonal, and metabolic parameters were determined. Student's t-test, chi(2)-test, and Spearman correlation test were used for statistical analysis., Results: The ovarian artery pulsatility index (PI), resistance index (RI), and SD ratios were significantly lower in PCOS than in controls on the right side (p < 0.001, p = 0.02, p = 0.001, respectively) as well as on the left side (p < 0.001, p < 0.001, p < 0.001, respectively). The uterine artery systolic/diastolic (S/D) ratio was higher on both sides (p = 0.01) and the PI was higher on the left side (p = 0.02) in PCOS than in controls. The right uterine artery PI was positively correlated with luteinizing hormone and hemoglobin (r = 0.417, p = 0.043; r = 0.427, p = 0.033, respectively), the right uterine artery S/D was positively correlated with body mass index (r = 0.479, p = 0.015), and the left uterine artery PI was positively correlated with insulin (r = 0.458, p = 0.021)., Conclusion: Doppler sonography of the utero-ovarian circulation may contribute to the evaluation of PCOS patients and a better understanding of the pathophysiology of this syndrome.

The application of Nd:YAG lasers in endodontics has been explored by many investigators for different purposes. The aim of this in vitro study is to evaluate the effects of Nd:YAG laser on osteoblast cell cultures. A 1,064 nm Nd:YAG laser was used to irradiate human osteoblast-like cells (Saos-2) in noncontact mode for 10 s with different energy settings. The settings varied were pulse energy (20-120 mJ), pulse repetition rate (10-30 Hz), and power output (0.2-3.6 W). He-Ne, the aiming beam of Nd:YAG laser, was used in noncontact mode for 10 s. After 7-, 14-, and 21-day incubation period, cell viability and proliferation were evaluated with methylthiazoletetrazolium (MTT) colorometric method. The comparison of average MTT values gave no statistically significant difference between 20 mJ, 10 Hz, He-Ne, and control (p < 0.05). The differences between all other groups were significant (p < 0.05). Increase in the pulse energy, pulse repetition rate, and power output has a negative effect on the cell viability and proliferation.

The purpose of this in vitro study was to observe the morphological changes and apical dye penetration at apical dentin surfaces induced by Nd:YAG laser irradiation at different power settings with and without a laser initiator. Seventy five single rooted human maxillary anterior teeth were used. Following the establishment of the working lengths, the root canals were enlarged with step-back technique. The apex of each root was resected 3 mm perpendicular to its long axis. Standard Class I cavities of 2 mm depth and 2 mm width were prepared. The teeth were randomly divided into five groups with fifteen teeth in each. In Group 1, the retrograde cavity preparations were lased with Nd:YAG laser at 2 W and those in Group 2 preparations were lased with Nd:YAG laser at 3.2 W. In Group 3, the retrograde cavity surfaces were lased with Nd:YAG laser at 2 W following the application of India ink. Group 4 was lased with the same settings of Group 2 after an absorbent cotton point soaked with India ink was inserted into the cut dentinal surfaces and the inner walls of the apical preparations. Group 5 served as control. Five teeth from each group were examined using scanning electron microscopy (SEM). The amounts of smear layer, debris, and recrystalized dentin present were assessed and scored. Retrograde cavities of ten teeth from each group were filled with amalgam to examine apical dye penetration. The teeth were immersed in 2% basic fuscin and kept for 48 hours. Dye penetration was evaluated by stereomicroscope at a magnification of X10. The results showed the usage of India ink with Nd:YAG laser enhanced the amount of melting and recrystalization of dentin and the radiation and initiator increased the leakage.

In this study, the aim was to assess the in vitro apical microleakage of a resin-based sealer used with two different adhesives. Thirty nine freshly extracted maxillary incisors were used. The teeth were decoronated at the cemento-enamel junction with a water-cooled fissure bur. Chemo-mechanical debridement of the root canals was accomplished with the step-back technique. The smear layer was removed by 19% ethylenediamine tetra acetic acid (EDTA). The roots were then divided into three experimental groups of thirteen teeth in each. Specimens in group 1 were filled with gutta-percha, AH Plus sealer, and water-based adhesive system (Syntac Single Component). Group 2 specimens were filled with gutta-percha, AH Plus sealer, and acetone-based dentin adhesive (Prime & Bond NT ). Specimens of group 3 were filled with only gutta-percha and AH Plus sealer (no adhesive was applied). The teeth were immersed into 2% methylene blue solution. Apical sealing qualities were assessed by measuring the linear dye penetration with a stereomicroscope. Dentin tubule penetration was observed under scanning electron microscopy (SEM). Results showed no statistically significant difference between the materials used, however, the leakage in group 2 was less than group 1 and 3.

The main objective of this in vitro study was to evaluate the effects of the operator's experience level and pre-flaring on the accuracy of the results of three different brands of a new generation of root canal measuring devices, as well as the comparison among them. Extracted human teeth were prepared and then actual length and electronic length measurements were made by three different operators according to a double-blind technique. Three different operators performed electronic measurements on each specimen separately with three different electronic root canal measuring devices using in vitro models. Measurements were repeated by all operators after the pre-flaring. Taking the clinical tolerance of +/- 0.5 mm into account, there was no statistically significant difference between the accuracy of the instruments (P > 0.01). However, the results obtained from the Bingo electronic apex locator in pre-flared canals by the beginner operator were statistically significant (P < 0.01). All of the instruments had a clinically acceptable result at the tolerance of +/- 0.5 mm. If the instruments are used in accordance with the manufacturer's instructions, experience with electronic root canal measurement is not essential. However, the operator has to be more careful when working on pre-flared canals.

Statement of Problem: Determination of the fracture resistance of various restorative materials in Class II approximal slot restorations has not been studied., Purpose: This study evaluated the effects of retention grooves and different restorative materials in Class II approximal slot restorations. To explore the possibilities for further research, the probable effects of preparation size and loading angle were investigated in a limited manner., Material and Methods: Ninety sound, caries-free human maxillary premolars were divided into 9 groups. The cavities were prepared either by hand or in a computer-controlled CNC machine with or without retention grooves. Four were restored with adhesive amalgam, another 4 with composite, and a single group with Compomer resin. The gingival floor depth was 1.5 mm. The specimens were loaded at an angle of 13. 5 degrees to their longitudinal axes by using a computer-controlled material testing machine until failure occurred. For one specific preparation of adhesive amalgam, loading was applied at 0 and 30 degrees to determine the probable effects of the loading angle. For a specific composite, resin application, the effects of the change in gingival floor depth were analyzed by assigning the depth to 2.0 mm., Results: Composite and Compomer resin and composite exhibited better performance than amalgam. The existence of the retention grooves proved to be effective for adhesive amalgam restorations but did not have any advantageous effect in composite and Compomer restoration., Conclusion: For improved fracture resistance in small approximal restorations, the use of composite was the appropriate choice. Compomer also gave satisfactory results. Use of amalgam restoration should be accompanied with retention grooves and an adhesive system to improve its performance.

Fluoride release from six light-activated restorative materials, including two resinmodified glass-ionomers, two composites, and two compomers, was evaluated and compared with one conventional acid-based glass-ionomer cement. The amount and rate of release varied among the tested materials. Both resin-modified glass-ionomers and the conventional acid-base glass-ionomer cements released more fluoride then the composites and compomers (p < 0.05). Additionally, composite materials released less fluoride than compomer materials (p < 0.05). Release of fluoride by the tested materials showed a significant decrease after all the tested time intervals.