Plastic Tip Research Articles

Ultrasonic Testing of a Grouted Steel Tank for Debonding Conditions

The non-invasive detection of debonding conditions and cavities beneath the wall of a steel tank are common applications in a variety of engineering and construction fields. Compressional ultrasonic waves have been used for the evaluation of steel plate thicknesses; however, they lack energy for penetrating a Portland cement grout in contact with a steel wall to detect debonding conditions. In this work, a joint analysis of surface waves and Lamb waves (high and low frequency) is used for the detection of debonding conditions in a scale model grouting steel tank. The propagation of high frequency ultrasonic waves generated by a 50-kHz transmitter along the side of the tank model is analyzed in the time domain and the frequency domain. In addition, using instrumented hammers with plastic or aluminum tips (low frequency sources) and a 50-kHz transmitter, three different configurations are used for the analysis of surface waves. The low-frequency Rayleigh waves generated by the hammer are used for void detection. Fourier spectra of the measured signals indicate that the effect of a void on the waves propagating through the medium is reduced when there is debonding. The comparisons of theoretical (high frequency) dispersion curves with experimental ones, computed from frequency wavenumber (FK) spectra, show that Lamb waves dominate the surface response in the wall of the steel tank. High frequency Lamb waves are successfully used in the detection of debonding between the tank wall and the grout because of the lower attenuation measured on top of the void.

Handheld mechanical nociceptive threshold testing in dairy cows – intra-individual variation, inter-observer agreement and variation over time

ObjectiveTo examine the use of handheld methodology to assess mechanical nociceptive threshold (MNT) on cows kept loose-housed. Study designProspective randomized partial cross-over experimental study. A one-factor (test day) design was used to evaluate MNT over time. AnimalsOne hundred and fifteen healthy, loose-housed Danish Holstein cattle. MethodsWe evaluated intra-individual variation, inter-observer agreement and variation over time of MNT using two handheld devices and two stimulation sites. Mechanical, ramped stimulations were performed with an algometer (6.5 mm diameter steel probe, 0–10.0 kgf) or an electronic von Frey device (plastic tip with diameter 0.8 mm, 0–1000 gf). Each cow received 5–6 consecutive stimulations within a 2 × 5 cm skin area on the dorsal or lateral aspect of the left third metatarsus until an avoidance reaction occurred. We investigated the difference in precision [expressed as coefficient of variation (CV)] between the combinations of devices and stimulation sites. The inter-observer agreement and the difference in MNT between test day 1, 3, 7, 10 and 24 were investigated for selected combinations. Data were analysed in mixed models and Bland-Altman as relevant. ResultsThe CVs did not differ [range 0.34–0.52 (p = 0.1)]. Difference between observers (95% limits) was 0.2 kgf (2.8) and 4 gf (369) for the algometer and von Frey device, respectively. Mechanical nociceptive threshold increased from 361 on test day one to 495 gf on test day 24 (p < 0.01). Conclusion and clinical relevanceAll methods showed a high degree of intra-individual variation, and no combination of device and stimulation site showed superior precision. Mean difference between observers was low, and MNT was not consistent over time. Further development of the methods is required before they can be used in research to investigate possible relations between claw lesions and hyperalgesia.

Use of plastic tips in artificial feeding of Dermacentor (Anocentor) nitens females Neumann, 1897 (Acari: Ixodidae)

The establishment of laboratory colonies of ticks is often hampered by their lack of adaptation to alternative hosts. The aim of this study was to artificially feed partially engorged Dermacentor (Anocentor) nitens females through plastic tips, and to identify what are the optimal conditions of application of this technique to get as much as possible close to the natural conditions. The technique of artificial feeding through plastic tips allowed the engorgement of D. nitens ticks to a final weight within the normal range for the species.

APOBEC3G exerts tumor suppressive effects in human hepatocellular carcinoma

In this study, we collected 44 hepatitis B virus surface antigen positivity HBsAg (+) tumor and nontumor hepatocellular tissues from hepatocellular carcinoma (HCC) patients during hepatectomy, and quantified the APOBEC3G (A3G) mRNA by using a real-time PCR. Our results showed higher expression of A3G mRNA in the nontumor tissues than in the tumor tissues of the HBsAg (+) HCC patients. To further investigate this phenomenon, we constructed a pLV-A3G vector and transfected it into the human HCC cell line, Hep 3B. The results of an immunofluorescence analysis showed the overexpression of A3G in the cytoplasm. We then evaluated A3G cytotoxicity by using a cell viability assay (MTS assay), the results of which showed that Hep 3B cell viability was 88 and 58% after the transfection of pLV and pLV-A3G, respectively, indicating the growth inhibitory effects of A3G on Hep 3B cells. To further evaluate the tumor suppressive effects of A3G, we used a plastic pipette tip to scratch Hep 3B cells grown on a culture dish (to 70-80% confluence) after transfection with pLV-A3G. Our data indicated a ratio of wound closure of 100% in the control cells and in the pLV-expressing cells, compared with 43% in the pLV-A3G-overexpressing cells, 72 h after the wound scratch, as observed using phase-contrast microscopy. These results indicated that A3G inhibits wound healing in Hep 3B cells. Overall, our results suggest that A3G inhibits the growth of human hepatoma cells.

Instrumentation With Ultrasonic Scalers Facilitates Cleaning of the Sandblasted and Acid-Etched Titanium Implants

Mechanical instrumentation is widely used to debride dental implants, but this may alter the surface properties of titanium, which in turn may influence bacterial adhesion and make it more difficult to remove the biofilm. This in vitro study was performed (1) to assess the amount of biofilm formation on a sand-blasted and acid-etched titanium fixture treated with ultrasonic scalers with metal, plastic, and carbon tips and (2) to evaluate how this treatment of titanium surfaces affects implant cleaning by brushing with dentifrice. The titanium fixtures were treated with various ultrasonic scaler tips, and surface roughness parameters were measured by confocal microscopy. Biofilm was formed on the treated fixtures by using pooled saliva from 10 subjects, and the quantity of the adherent bacteria was compared with crystal violet assay. The fixture surfaces with biofilm were brushed for total of 30 seconds with a toothbrush with dentifrice. The bacteria remaining on the brushed fixture surfaces were quantified by scanning electron microscopy. Surface changes were evident, and the changes of the surfaces were more discernible when metal tips were used. A statistically significant decrease in roughness value (arithmetic mean height of the surface) was seen in the 2 metal-tip groups and the single plastic-tip group. After brushing with dentifrice, the treated surfaces in all the treatment groups showed significantly fewer bacteria compared with the untreated surfaces in the control group, and the parts of the surfaces left untreated in the test groups. Within the limits of this study, treatment of titanium fixture surfaces with ultrasonic metal, plastic, or carbon tips significantly enhanced the bacterial removal efficacy of brushing. Thorough instrumentation that smooths the whole exposed surface may facilitate maintenance of the implants.

Push-out bond strength of fiber posts to root canal dentin using a one-step self-etching adhesive: the effect of solvent removal and light-curing methods.

To evaluate the effect of solvent removal and light-curing methods on the push-out bond strength of fiber posts to root canal dentin using a one-step self-etching adhesive. Eighty single-rooted, single-canal human mandibular premolars were used in this study. After removal of the crown, the pulp was extirpated and the post space was prepared. The teeth were divided into two main groups according to the solvent removal method, either using the paper point or the air-drying method. Each of the above main groups was further subdivided into 4 subgroups according to the light-curing method: group 1: both adhesive and resin cement were cured from the top of the post in the same step (cocuring) for 40 s; group 2: the adhesive was light cured for 20 s and the resin cement for 40 s; group 3: the adhesive was light cured for 40 s as was the resin cement; group 4: an intracanal tip was used to cure the adhesive inside the post space for 20 s. In groups 1 to 4, the solvent was evaporated using oil-free compressed air for 5 s from the root surface and excess adhesive was removed from inside the canal using a paper point. In groups 5 to 8, the adhesive and cement were applied and light cured as in groups 1 to 4, except the solvent was evaporated (air dried) from inside the post space using an intra-canal disposable plastic tip attached to the tip of a 3-way syringe. After 24 hours, three 2-mm-thick root slices were obtained from each root. Each slice was subjected to the push-out bond strength test at a crosshead speed of 0.5 mm/min. Factorial analysis (two-way ANOVA) was run to test the effect of solvent evaporation method, light-curing method, and their interactions on bond strength. One-way ANOVA followed by Duncan's Multiple Range Test were used to test the effect of lightcuring method on bond strength within each solvent evaporation method. Student's t-test was performed to compare the effect of solvent evaporation method on bond strength within each light-curing method. Two-way ANOVA revealed that the solvent removal method had a significant effect on the bond strength of fiber post to root canal dentin. Neither the light-curing method nor the interaction between the two independent variables had a significant effect on the push-out bond strength. Only air drying the one-step self-etching adhesive could influence the bond strength of the fiber post to root canal dentin.

Cleaning Effectiveness of Implant Prophylaxis Instruments

The aim of this study was to evaluate the cleaning effectiveness of implant prophylaxis instruments on polished and acid-etched implant surfaces. Biofilm layers of Streptococcus mutans were grown on a total of 80 titanium disks; 40 disks were polished and 40 were acid-etched. Five disks of each surface were cleaned using each of seven implant prophylaxis instruments: (1) manual plastic curette, (2) manual carbon fiber-reinforced plastic (CFRP) curette, (3) sonic-driven prophylaxis brush, (4) rotating rubber cup with prophylaxis paste, (5) sonic-driven polyether ether ketone (PEEK) plastic tip, (6) ultrasonic-driven PEEK plastic tip, and (7) air polishing with amino acid (glycine) powder. Ten disks (five of each surface type) served as controls. After cleaning, the surfaces with remaining bacteria were assessed by light microscopy. Statistical analyses of the results were performed with one-way and two-way analyses of variance with Bonferroni-Dunn multiple comparisons post hoc analysis (α = .05). The cleaning effectiveness of the plastic curette was significantly lower than those of all machine-driven instruments on the polished surface. Significantly lower cleaning effectiveness occurred with the CFRP curette compared to the prophylaxis brush and to both oscillating PEEK plastic tips on the polished surface. The rubber cup provided less cleaning effectiveness compared to the ultrasonic PEEK plastic tip and air polishing on the acid-etched surface. Superior results, with less than 4% of the biofilm remaining, were obtained for both oscillating PEEK plastic tips and air polishing on both implant surfaces. The cleaning ability of the prophylaxis brush, rubber cup, and ultrasonic PEEK plastic tip differed significantly between both surface structures. Cleaning effectiveness, ie, less than 4% of the biofilm remaining, was not observed with all tested implant prophylaxis instruments. The cleaning ability of the devices depended on the implant surface structure.

Periapical repair and apical closure of a pulpless tooth using calcium hydroxide-A case report

Aim : To report the induction of apical root development by calcium hydroxide in teeth with pulp necrosis and periapical radiolucency. Method and Materials : Two cases were presented where the calcium hydroxide and iodoform paste Metapex® was placed in the root canals of immature permanent teeth using disposable plastic tips. The teeth involved were evaluated radiographically at regular intervals for the first 12 months after placement of the paste. At the end of 12 months both the cases showed continued root growth and apical closure (apexification) with no evidence of periapical pathology. Conventional endodontic treatment was then performed. Results : In both the clinical cases presented, a combination of calcium hydroxide and iodoform paste (Metapex®) was used and showed promising results in inducing root-end growth and closure after 12 months. Conclusion : In these two clinical cases, the calcium hydroxide and iodoform paste Metapex® (Meta Biomed Co. Ltd., South Korea) was found to induce apical closure when assessed radiographically. Over a period of 12 months both the cases showed continued root growth. Clinical Significance : The calcium hydroxide and iodoform paste Metapex® promoted continued root-end growth with apexification in the nonvital immature permanent teeth treated.

State‐of‐the‐art review on extended stress intensity factor concepts

ABSTRACTThe stress intensity factor concept for describing the stress field at pointed crack or slit tips is well known from fracture mechanics. It has been substantially extended since Williams' basic contribution (1952) on stress fields at angular corners. One extension refers to pointed V‐notches with stress intensities depending on the notch opening angle. The loading‐mode‐related simple notch stress intensity factors K1, K2 and K3 are introduced. Another extension refers to rounded notches with crack shape or V‐notch shape in two variants: parabolic, elliptic or hyperbolic notches (‘blunt notches’) on the one hand and root hole notches (‘keyholes’ when considering crack shapes) on the other hand. Here, the loading‐mode‐related generalised notch stress intensity factors K1ρ, K2ρ and K3ρ are defined. The concepts of elastic stress intensity factor, notch stress intensity factor and generalised notch stress intensity factor are extended into the range of elastic–plastic (work‐hardening) or perfectly plastic notch tip or notch root behaviour. Here, the plastic notch stress intensity factors K1p, K2p and K3p are of relevance. The elastic notch stress intensity factors are used to describe the fatigue strength of fillet‐welded attachment joints. The fracture toughness of brittle materials may also be evaluated on this basis. The plastic notch stress intensity factors characterise the stress and strain field at pointed V‐notch tips. A new version of the Neuber rule accounting for the influence of the notch opening angle is presented.

Determining if Telomeres Matter in Colon Cancer Initiation or Progression

The nucleus of each human cell contains 46 linear chromosomes (92 ends) that are capped by thousands of repetitive TTAGGG DNA sequences (similar to the plastic tips on shoelaces). These ends, called “telomeres” have complex roles in aging and cancer and have proven to be intricately involved in such pivotal processes as the protection of genetic material, the completion of chromosome replication, the regulation of cellular aging due to progressively shortening telomeres throughout life, the initial protection against unlimited cellular growth, and, in combination with other alterations, the promotion of cancer progression. A collection of six proteins that either bind or associate with telomeres (the shelterin complex) begin to resolve a central question of how cells distinguish telomere ends from typical genomic DNA double-strand breaks (1). The consequences of telomere dysfunction are becoming more apparent by examining a growing list of human genetic diseases called telomeropathies. In certain inherited and familial cases of idiopathic pulmonary fibrosis, dyskeratosis congenita, and sporadic bone marrow failure (aplastic anemia), inheritance of short telomeres due to mutations in genes involved in the ribonucleoprotein telomerase holoenzyme lead to premature aging phenotypes (2). Telomerase is the cellular reverse transcriptase that can add TTAGGG repeats onto the telomeres and is active during early human development (3) but is silent in most adult tissues except proliferating stem cells, unless it is upregulated as part of cancer progression (4).

Transvenous placement of the subcutaneous coil electrode to reduce elevated defibrillation thresholds: an alternative to an azygous or subcutaneous coil

Purpose: Despite waveform optimization, high output devices, dual coil electrodes (DCE) or the addition of a standard (Medtronic Transvene) proximal coil (TVCE) high defibrillation thresholds (DFT) continue to be a problem in patients with implantable cardioverter defibrillator (ICD). Placement of a coil electrode (Medtronic 6996) posterior in the subcutaneous (SQ) tissue (SQCE) reduces DFTs but requires a second procedure in many centers and is not readily applicable to a right-sided implant. Placement of a TVCE in the azygous vein or coronary sinus can be challenging and may be extremely difficult/dangerous to extract. We present an alternative approach to high DFT's by transvenous rather than SQ placement of the SQCE. Methods: Between Sept 2009 and May 2012, eight patients with high DFT's (mean ≥ 35.3 SD ± 2.7) despite a DCE (proximal coil surface area {SA} 860 mm2) or addition of a TVCE (SA 125 mm2) who had a SQCE (SA 500 mm2) placed in the left innominate/SVC (7 left-sided implants) or azygos vein (1 right-sided implant). After connecting the SQCE to the proximal port, the generator was implanted in the subcutaneous space and DFT's repeated. Results: The mean age was 63±16 years (range 30-79) with 3 females and 1 right-sided implant. The initial ICD lead was dual coiled in seven with the addition of a TVCE in one. After removal of the plastic tip, the subcutaneous coil electrode was positioned in the left innominate/SVC (n=7) and the azygos vein (n=1) for the right-sided implant. The mean DFT was reduced from > 35.3 J ± 2.7 to ≤ 20.3 J ± 4.9 (p=0.003) and the high voltage lead impedance reduced from 41.5±16.7 to 31.1±6.8 Ω (p = 0.2) There were no perioperative complications such as lead dislodgements, fractures, infections or sensing problems noted till last follow up. One patient expired from progressive congestive heart failure one year after the implant. None of the patients have had a spontaneous arrhythmic episode and there were no inappropriate therapies recorded since implant till last follow up. Conclusion: Despite a lower SA than the proximal coil of a DCE, transvenous placement of the SQCE in the left innominate/SVC reduces high DFT's below that seen with a dual coil system and does not require a second procedure. For right-sided implants, azygos placement of the subcutaneous coil may be preferred than the conventional transvenous coil for reducing DFT's.

In Vitro Analysis of the Efficacy of Ultrasonic Scalers and a Toothbrush for Removing Bacteria from Resorbable Blast Material Titanium Disks

A resorbable blast material (RBM) surface is reported to have a higher bone-to-implant contact percentage than machined surfaces, but modified surfaces with rougher textures have been shown to favor colonization by bacteria and development of peri-implantitis. Therefore, this in vitro study compares the effects of different instruments on surface roughness and removal of bacteria from RBM titanium implant disks. RBM titanium disks were treated with various ultrasonic scaler tips and a toothbrush, and change in surface roughness was measured by confocal microscopy. The disks were incubated with bacteria, and instruments made of carbon or plastic, two metal ultrasonic scaler tips, or a toothbrush were used to remove the attached bacteria. The amount of remaining bacteria was evaluated using a crystal violet assay. The change in surface structure following different treatment modalities was analyzed by confocal microscopy. A statistically significant decrease in the arithmetic mean value of RBM surfaces (R(a)) was observed after treatment with an ultrasonic scaler with a metal tip. The use of a metal tip (rather than a carbon or plastic tip) and brushing with dentifrice was more efficient in removing bacteria from the contaminated titanium surface according to the crystal violet assay. Within the limits of this study, the use of a metal tip may be effective in removing bacteria from contaminated surfaces.

Abstract 5402: Synergism of Metformin and DFMO on colon cancer proliferation and migration.

Abstract Introduction: Metformin has been shown to inhibit cancer cell growth via activation of MAP kinase with resultant inhibition of mTOR signaling pathway. ODC, a key enzyme in polyamine biosynthesis, was found to be overexpressed in colon cancer. We determined the effect of metformin in combination with DMFO, an ODC inhibitor, on tumor proliferation and migration in human colon cancer cells. Methods: Human colon cancer cells, HCT 116 and HT 29, were treated with Metformin, DFMO, or combination. Cell proliferation assay was performed using Cell Titer Blue proliferation assay. Cell migration assay was performed by seeding colon cancer cells in 24-well plate. After overnight incubation, an artificial homogenous wound was created onto the monolayer with a plastic micropipette tip. After wounding, the migration of cells into the wound was observed up to 72 hours at various time points. Quantitative RT-PCR for ODC1 detection was performed using Assay-on-Demand Hs00159739-ml. GAPDH served as control. Western blotting was performed to determine the expression of AMP kinase, mTOR, p70S6K and 4E-BP1. Data were presented as means ± SD for the three separate experiments. For comparison between groups, the student's t test was used and p&amp;lt; 0.05 was considered to be statically significant. Results: There was dose-dependent (1-10 mM for DFMO and 1-20 mM for metformin) time-dependent (up to 96 hours) inhibition of cell proliferation and migration with either metformin or DFMO in both HCT 116 and HT 29 cells. Synergistic inhibition was observed with the combination treatment (5 mM DFMO and 5 mM Metformin) on both cell migration and proliferation at 24 hours compared with either agent alone. There was synergistic inhibition of ODC expression with the combined treatment compared with DFMO alone at 24 hours (p&amp;lt;0.01). The combination treatment also lead to significant enhancement of AMPK activation and increased phosphorylation of AMPKα at Thr-172 compared with metformin alone (p&amp;lt;0.01). The combination treatment resulted in significant inhibition of mTOR signaling with decreased phosphorylation of mTOR, p70S6K and 4E-BP1 in treated cancer cells, when compared with individual drug treatments. Inhibition of proliferation and migration was significantly greater in the mismatch-repair defective HCT 116 cells than HT 29. Conclusion: We have observed a synergistic effect of metformin and DFMO in suppressing human colon cancer proliferation and migration. The synergism reflects enhanced inhibition of both polyamine synthesis and mTOR signaling pathways by the drug combination. Citation Format: Yanping Zhang, Luz M. Rodriguez, Ronald Lubet, Eddy C. Hsueh. Synergism of Metformin and DFMO on colon cancer proliferation and migration. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5402. doi:10.1158/1538-7445.AM2013-5402

Repeated Respiratory Failure and Failed Extubation Following Intraoperative Advanced Airway Device Endotracheal Intubation

Intraoperative airway management by anesthesiology providers has evolved over the years to include many specialized devices and techniques that can have tremendous impact on the care of the perioperative critically ill patient. When perioperative patient care issues arise, anesthesiologists and perioperative critical care specialists should both be actively involved in a dialogue regarding many the relevant patient care issues, including any airway and respiratory function problems. Additionally, critical care specialists should be familiar with the use and potential complications of the increasingly diverse airway (and non-airway) tools and devices used by anesthesiologists in the operating room. The authors present a case report of a 66-year-old man who suffered repeated postoperative respiratory failure following an uncomplicated upper extremity orthopedic procedure. The patient developed unexplained, repeated postoperative respiratory failure that necessitated reintubation related to the accidental and unrecognized retention of a plastic tip extender from a Bullard fiber-optic laryngoscope. After transfer to the ICU, the patient continued to have significant respiratory distress requiring aggressive post-extubation noninvasive mechanical ventilation. The cause of this complication was not diagnosed by the anesthesiologist or the intensive care team throughout the course of this patient’s respiratory failure. Ultimately, the patient spontaneously expectorated the tip extender with rapid improvement in his respiratory function. This case highlights the importance of the dialogue that should occur between anesthesiologists and critical care specialists when unexpected and/or unexplained perioperative complications occur.

Effect of Spraying Pressure and Usage on Discharge Rate and Wear of Hollow Cone Nozzle having different Nozzle Tip Material

Spray nozzle and its tips, the most critical component of spray application equipment which influences the efficiency and effectiveness of the chemicals applied are the most neglected component in today’s farming. Hollow cone nozzles having different orifice tip materials (plastic, brass and stainless steel) were evaluated at three nozzle pressures (1.0, 3.0 and 5.0 kg.cm-2) to assess their performance in terms of increase in discharge rate and wear of orifice tip diameter. Percent increase in discharge rate of different hollow cone nozzles at three pressures and time interval of usage showed that that plastic tip material could work within the permissible limit of 15 % increase in discharge rate for about 90, 35, 10 h of use at pressure of 1.0, 3.0 and 5.0 kg.cm-2, respectively. Similarly, brass tip material can work for about 50, 30 and 7.5 h and stainless steel for 90, 50 and 17.5 h, respectively, at these pressures. The increase in average orifice diameter was higher in case of brass tip nozzle as compared to plastic and stainless steel tip nozzles at all pressures.

A Novel In Vitro Injury Model Based on Microcontact Printing Demonstrates Negative Effects of Hydrogen Peroxide on Axonal Regeneration both in Absence and Presence of Glia

Abstract The molecular processes involved in axonal regeneration after traumatic brain injury (TBI) are still not fully understood. In this study, we have established a novel in vitro injury model of TBI based on microcontact printing (μCP) that enables close-up investigations of injured neurons. The model is also suitable for quantitative measurements of axonal outgrowth, making it a useful tool in the studies of basic mechanisms behind axonal regeneration. Cortical neurons from mouse embryos are cultured on μCP cover-slips for 8 days, and the neurons are then injured in a precise manner using a thin plastic tip that does not affect the μCP pattern of extracellular matrix proteins. By close-up time-lapse experiments and immunostainings, we show that the neurons have a tremendous capacity to regenerate their neurites after injury. The cut induces growth cone formation, and the regenerating axons strictly follow the μCP pattern. Moreover, by using the injury model, we demonstrate that hydrogen peroxide (H2O2) decreases axonal regeneration after injury without affecting the neurons' ability to form growth cones. Co-culture with glial cells does not rescue the axonal regeneration, indicating that the mechanism by which H2O2 affects axonal regeneration differ from its cytotoxic effect.

Plastic spatula with narrow long tip provides higher satisfactory smears for Pap test

Background:Ayre spatula for cervical smear collection is being used despite the suggestion that different modified spatulas provide more satisfactory sampling.Aims:To see whether the cytological pickup improves with the use of long tipped spatula.Setting and Design:Rurally based University Hospital; crossover study.Materials and Methods:Pap smear using Ayre spatula in 500 and with plastic narrow long tip (Szalay) spatula in 500 clinic attending women was taken and analyzed. Crossover smears were taken with modified spatula in 163 and using Ayre spatula in 187 women after 2 weeks of initial smears. The same pathologist made cytological reporting for all smears and was unaware of the type of spatula used.Results:Smears from Ayre spatula had significantly higher reports of inadequate smears (94 of 500 vs. 68 of 500 for Ayre and Szalay, respectively; P = 0.032) and it remained so even after crossover (94 of 187 vs. 70 of 163 for Ayre and Szalay, respectively; P = 0.2). Cellular quality appeared better with smears taken using Szalay spatula, but the overall abnormal smear detection rate remained similar with either collection tool (χ2 = 1.5; P = 0.2).Conclusions:Proportion of satisfactory smears is higher when long tip plastic spatula is used for collection of sample.

Nasal Aesthetics

Plastic surgeons often approach nasal aesthetic evaluation with the aid of seemingly objective measurements. However, ideal measurements of an attractive nose, as suggested in the literature, might not apply on a cross-cultural basis. Given these controversies, this study aimed to investigate the cultural and ethnic impact on nasal shape preferences. Computerized images of a model's nose were generated in which the nasal width, root, tip, dorsum, and projection of the lips and chin could be altered. A survey containing these images was sent to over 13,000 plastic surgeons and lay people in 50 different countries, with a total response rate of 9.6 percent. Demographic information about the interviewees was obtained. Preferred dimensions of the nose were broken down according to geographic, ethnic, occupational, and sex variables. Interregional comparison revealed that plastic surgeons from Latin America and the Caribbean overall prefer smaller and narrower noses, with more projecting tips, lips, and chins. Similar trends hold true when analyzing results from the general public. Significant differences were found comparing preferences between plastic surgeons and the general public. Plastic surgeons preferred wider nasal roots and tips and, in combination, more projected nasal dorsi, tips, lips, and chins. No universal parameter can define ideal aesthetics of the nose across cultures and ethnic backgrounds. As demonstrated, geographic, ethnic, and cultural factors influence aesthetic perceptions of patients and surgeons.

J and CTOD estimation formulas for C(T) fracture specimens including effects of weld strength overmatch

This work focuses on an evaluation procedure to determine the elastic–plastic J-integral and Crack Tip Opening Displacement (CTOD) fracture toughness based upon the η-method for C(T) fracture specimens made of homogeneous and welded steels. The primary objective of this investigation is to enlarge on previous developments of J and CTOD estimation procedures for this crack configuration while, at the same time, addressing effects of strength mismatch on the plastic η-factors. The present analyses enable the introduction of a larger set of factors η for a wide range of crack sizes (as measured by the a/W-ratio) and material properties, including different levels of weld strength mismatch, applicable to pipeline and pressure vessel steels. Very detailed non-linear finite element analyses for plane-strain and 3-D models of C(T) fracture specimens with centerline-cracked welds provide the evolution of load with increased load-line and crack mouth opening displacement required for the estimation procedure. Overall, the present study, when taken together with previous investigations, provides a fairly extensive body of results to determine parameters J and CTOD for different materials using C(T) specimens with varying overmatch conditions.

Effects of Ultrasonic Scaler Tips and Toothbrush on Titanium Disc Surfaces Evaluated With Confocal Microscopy

Instrumentation to remove plaque from dental implants may cause damage to the implant surface, and previous studies that have evaluated the effects of the ultrasonic scalers and brushing in experimental settings reported that substantial changes were seen on implant surfaces after mechanical plaque removal. There is limited information on changes of the surface profile and roughness of sandblasted acid-etched (SLA) and machined titanium surfaces after treatment with different instruments in simulated clinical situations. The purpose of this study was to evaluate the effects of oral hygiene instruments including various types of ultrasonic tips in simulated clinical settings and brushing with dentifrice on machined and SLA titanium surface with confocal microscopy. Both SLA and machined discs were treated with various ultrasonic scaler tips and brushing. Discs were either instrumented with 4 different ultrasonic scaler tips or brushed with dentifrice. The entire top surface of the discs was instrumented for a total of 40 seconds (20 seconds, 2 cycles). Brushing with dentifrice was done for 40 seconds. Roughness measurements were performed using a confocal microscope. The change of surface structure after different treatment modalities could be observed with the naked eye when compared with the untreated surface (SLA and machined groups). In case of SLA surfaces, the 2 metal tips produced greater changes on the titanium surfaces when compared with the plastic ultrasonic tips and brushing. On the machined discs, scratch lines over the original surfaces could be observed from all ultrasonic metal and plastic tips, but 2 metal tips produced significant and definite scratches on the original disc surfaces. This study showed the effects of different types of ultrasonic tips and brushing with dentifrice on both SLA and machined titanium surfaces in simulated clinical setting. Within the limits of our study, we suggest that metal or plastic ultrasonic scaler tips may be applied as usual to treat the SLA surface of dental abutment or fixture surfaces without increasing the irregularities on the titanium surfaces. However, in case of machined surfaces, ultrasonic metal tips cannot be recommended because the surface becomes rougher after treatment. In addition, brushing of titanium, regardless of surface treatment (SLA and machined surfaces), resulted in reduction of surface roughness. Meticulous oral hygiene with brushing must be reinforced for the patients with dental implants to maintain the exposed implant surface clean. Brushing with dentifrice may facilitate maintaining the exposed fixture surface clean by smoothening the surface.