Group F2 Research Articles

Differences in Cyclic Fatigue Resistance between ProTaper Next and ProTaper Universal Instruments at Different Levels

IntroductionNew designs and alloys have been developed to increase cyclic fatigue (CF) resistance of rotary files. The aim of this study was to compare CF resistance of ProTaper Universal (PTU; Dentsply Tulsa Dental, Tulsa, OK) and ProTaper Next (PTN, Dentsply Tulsa Dental) instruments at different points of curvature. MethodsA total of 420 files (240 PTU, S1, F1, F2, and F3 and 180 PTN, X1, X2, and X3) were divided in 14 groups of 30 instruments each. Instruments in groups S1–5, F1–5, X1–5, F2–5, X2–5, F3–5, and X3–5 were tested at 5 mm from the tip. Groups S1–12, X1–12, and F1–12 were tested at 12 mm from the tip because S1, X1, and F1 instruments have the same diameter at that level. Groups F2–8, X2–8, F3–8, and X3–8 were tested at 8 mm (F2/X2 and F3/X3, respectively, had the same diameter at 8 mm). All files were rotated at 300 rpm until fracture. CF resistance was tested in stainless steel curved canals (60°, r = 3 mm). Time to fracture was recorded. The mean half-life and beta and eta were calculated for each group and were compared with Weibull analysis. ResultsPTN instruments will last significantly longer than PTU files with a probability higher than 98% at all tested levels except for S1, which was the significantly the most resistant instrument to CF at 5 mm from the tip. ConclusionsPTU S1 was significantly the most resistant instrument at 5 mm from the tip. PTN files were significantly more resistant to CF than PTU instruments at all the other tested levels.

Vanishing of the First Continuous L2-Cohomology for II1 Factors

We prove that the continuous version of the Connes-Shlyakhtenko first L-cohomology for II1 factors, as proposed by A. Thom in [Th06], always vanishes. In [CS03], A. Connes and D. Shlyakhtenko developed an L2-cohomology theory for finite von Neumann algebras M , and more generally for weakly dense ∗-subalgebras A ⊂ M of such von Neumann algebras. Then in [Th06], A. Thom provided an alternative, Hochschild-type characterization of the first such L2-cohomology of M as the quotient of the space of derivations δ : M → Aff(M ⊗Mop) by the space of inner derivations, where Aff(M ⊗Mop) denotes the ∗-algebra of operators affiliated with M ⊗Mop. Thom also proposed in [Th06] a continuous version of the first L2-cohomology, by considering the (smaller) space of derivations δ that are continuous from M with the operator norm to Aff(M ⊗Mop) with the topology of convergence in measure. He noted that in many cases (e.g., when M has a Cartan subalgebra, or when M is not prime), this cohomology vanishes, i.e. any continuous derivation of M into Aff(M ⊗Mop) is inner. Following up on this work, V. Alekseev and D. Kyed have shown in [AK11] that the first continuous L2-cohomology also vanishes whenM has property (T), whenM is finitely generated with nontrivial fundamental group, or when M has property Gamma. Recently, V. Alekseev proved in [Al13] that this is also the case for the free group factors L(Fn). In this article, we prove that in fact the first continuous L2-cohomology vanishes for all finite von Neumann algebras. The starting point of our proof is a key calculation in the proof of [Al13, Proposition 3.1], which provides a concrete sequence of elements yn in the II1 factor M = L(F3) of the free group F3 with generators a, b, c, that tends to 0 in operator norm, but has the property that if a derivation δ : M → Aff(M ⊗Mop) satisfies δ(ua) = ua ⊗ 1 and δ(ub) = δ(uc) = 0, then δ(yn) does not tend to 0 in measure. More precisely, the yn’s in [Al13] are scalar multiples of words wn in a, b, c with the property that δ(wn) is a larger and larger sum of free independent Haar unitaries. In the case of an arbitrary II1 factor M , we fix a hyperfinite II1 factor R ⊂ M with trivial relative commutant, and then use [Po92] to “simulate” (in distribution) L(F3) inside M , with a any fixed unitary in M and bm, cm Haar unitaries in R such that a, bm, cm are asymptotically free. If now δ is a continuous derivation on M , then by subtracting an inner derivation, we may assume δ vanishes on R, thus on bm, cm. If δ(a) 6= 0, and if we formally define yn’s via the same formula as Alekseev’s, with a, bm, cm in lieu of a, b, c, then a careful estimation of norms of yn and δ(yn), which uses results in [HL99], shows that one still has ‖yn‖ → 0, while δ(yn) 6→ 0 in measure. Mathematics Department, UCLA, CA 90095-1555 (United States), popa@math.ucla.edu Supported in part by NSF Grant DMS-1101718 KU Leuven, Department of Mathematics, Leuven (Belgium), stefaan.vaes@wis.kuleuven.be Supported by Research Programme G.0639.11 of the Research Foundation – Flanders (FWO) and KU Leuven BOF research grant OT/13/079.

A comparison of desflurane consumption according to fresh gas flow.

A comparison of desflurane consumption according to fresh gas flow.

89 CONCENTRATION OF ZINC IN FLUID FOLLICULAR OF FEMALE HORSES

The follicular fluid manage and keeps the nutrition of the oocyte and granulosa cell, which are develop inside this liquid. As well this fluid contains growth hormones, growth factors, and some micro-minerals as zinc (Zn). Resources report that Zn could avoid the earlier meiotic detention of the gametes, strengthen the structure of the chromatin due to the discovery of the Zn fingers, while also decrease the oxidative damage and inhibit the electrodes transportation by connecting to the Cytochrome b. The goals of this research were to determine the Zn concentration in the follicular fluid of female horses and define suitable concentration and supplementation in an embryonic culture. The first step of this research was to obtain follicular fluid from 23 female horses; these were classified by follicular size: F1 <1 cm, F2 between 1 and 2 cm, F3 >2 cm. The Zn was measured by spectrophotometry atomic absorption (μg mL–1). The use of the statistics program SAS version 9.3 (SAS Institute Inc., Cary, NC, USA) with a complementary random model, with factorial adjustments. Significance was established when P < 0.001. Obtaining significant differences on the Zn concentration on different follicles (P < 0001). Group F1 0.68 ± 0.15 μg mL–1, F2 1.42 ± 0.17 μg mL–1, and F3 1.8 ± 0,32. Table 1 shows the results of the volume and total concentration. Results indicate that Zn concentration varies with size and maturity of the follicle. Therefore, Zn required to be supplemented could be different as a function of the follicular development; further studies are required to evaluate the embryonic response to Zn addition in different maturation media and to correlate with survival rates. Table 1.Concentration of zinc in fluid follicular of female horses

Assessment the papillary muscle function of functional mitral regurgitation using speckle tracking technology

Objective: To evaluate the function of left-side papillary muscles (PM) in ischemic and non-ischemic cardiomyopathy patients (ICM, NICM) with functional mitral regurgitation (FMR). Methods: Eighty control subjects were enrolled (group H). Sixty ICM patients with FMR were enrolled according to coronary angiography. Sixty NICM patients with FMR were enrolled as Contemporary definitions and classification of the cardiomyopathies. All patients were divided into three groups as the degree of FMR, mild FMR is group F1, moderate FMR is group F2, severe FMR is group F3. Standard transthoracic echocardiography were performed. All data were exported to Philips Qlab 8.1 workstation for 2D STI analysis. The parameters include: the longitudinal strain of anterior PM (APM), posterior PM (PPM) (ALS, PLS), the peak time of APM, PPM (APT, PPT), and the delay time of peak value between APM and PPM (DT). Results: The results illustrate ALS and PLS decreased, the APT, PPT, DT increased with increased of FMR degree (F>3.84,p 0.05). In addition, compared with control subjects, there was significant alteration of PM acoustics and morphologic features in FMR patients. Conclusions: Our study found the PM longitudinal strain decreased with an increase of FMR degree, both of function and desynchronization of APM and PPM play important role in FMR occurrence. Specifically, our results part explained the phenomenon that cardiac resynchronization therapy can reduce the degree of FMR. So these findings may helpful to screen right patients for this therapy.

Effect of resin-based materials on fracture resistance of endodontically treated thin-walled teeth

Composite resins are recommended for root reinforcement, but little information exists about self-adhesive resin cements that eliminate the acid etching and bonding steps. The purpose of this study was to compare the fracture resistances of teeth restored with 2 different diameters of cast and fiber posts and to evaluate the effectiveness of increasing internal root thickness with 2 resin-based materials to reinforce thin-walled teeth. Ninety maxillary incisors were endodontically treated and divided into 9 groups. In the first 4 groups, teeth were restored with tapered end cast (C1.3 and C1.7) and fiber (F1.3 and F1.7) posts of 1.3 and 1.7 mm diameters. In the other 5 groups, the root canals were enlarged to simulate the thin-walled teeth and restored with low viscosity composite resin with fiber posts of 1.3 and 1.7 mm diameters (LF1.3 and LF1.7), self-adhesive resin cement with fiber posts of 1.3 and 1.7 mm diameters (SF1.3 and SF1.7), and cast posts of 4 mm diameter that fit in post spaces (C4). Teeth were loaded to fracture at a 135-degree angle to their long axis. Data were analyzed with 2-way ANOVA and the Tukey HSD test (α=.05). Significant difference (P<.001) existed between the fracture resistances of the teeth restored with cast (C1.3, 588.4 ±72.7 N) and fiber (F1.3, 375.3 ±53.8 N) posts of 1.3 mm diameter; however, no significant difference was found between 1.3 and 1.7 mm post diameters. The teeth restored with the resin-based materials with fiber posts, groups SF1.3 (331.6 ±135.2 N), SF1.7 (535.7 ±134.4 N), LF1.3 (432.1 ±120.3 N) and LF1.7 (563.8 ±128.8 N), demonstrated fracture resistance values similar to or higher than those of the teeth restored with the fiber posts, groups F1.3 (375.3 ±53.8 N) and F1.7 (461.8 ±98.4 N). The parallel-sided cast posts C4 (799.8 ±228.9 N) of 4 mm diameter demonstrated the highest fracture resistance of all groups (P<.001). The fracture resistance of the teeth increased as the elastic modulus of the posts increased but was not affected by small diameter variations of the posts. The resin-based materials were able to preserve and reinforce the remaining tooth structures.

Comparison of ILMA Guided Tracheal Intubation in the Lateral Position with the Supine Position

Background: The ILMA has been established as a valuable airway management device in the supine position, in both elective and emergency situations, for both ventilation and intubation. Intubation in lateral position might be necessary in some congenital syndromes, morbid obesity, or after accidental extubation in laterally positioned patients. This study was undertaken to evaluate the ILMA for intubation of patients in the lateral position and compare it with intubation in the supine position. Aims: To determine and compare the success rate, time taken, and complications of intubation with the ILMA in the lateral versus supine position. Settings and Design: Prospective, clinical investigation, in a tertiary level, multispecialty hospital. Methods and Material: Seventy ASA I-II patients scheduled for elective surgeries were randomly allocated into two groups of 35 patients each. The groups F1 and F2 consisted of patients who were intubated with the ILMA in the supine and lateral positions, respectively. The comparison of the two positions was based on: success of intubation, success at first attempt, number of attempts, intubation time, and incidences of oesophageal intubation, oxygen desaturation, mucosal injury and postoperative sore throat. Statistical Analysis used: The data was analysed, and for comparison of mean between two groups, unpaired student “t”-test was applied. ?2-test or Fischer exact test were applied for categorical variables like number of attempts, incidence of mucosal injury etc. Results: The intubation success rate was 100% in both positions. The success rate of intubation in the first attempt was 97.1% in supine, and 94.3% in the lateral position, and was comparable. The average intubation time was significantly more in the lateral, as compared to the supine position (45.82 versus 38.51 seconds). The incidence of intra, and post-operative complications was low in both the positions. Conclusion: These results suggest that the ILMA is a useful device for tracheal intubation in the lateral position. The difference in intubation time, though significantly more (statistically) in the lateral as compared to the supine position, had little clinical relevance. DOI: http://dx.doi.org/10.3126/ajms.v3i4.5667 Asian Journal of Medical Science Vol.3(4) 2012 pp.32-38

Gender determines the effect of atracurium priming technique in a randomized study

To evaluate the effect of priming atracurium over onset time and intubating time of general anesthesia between different genders. Sixty-six male and sixty-four female patients, ASA I-II, aged 18-65 years, were randomly divided into four groups: group M1: male patients with saline priming; group M2: male patients with priming atracurium dose of 0.05 mg/kg; group F1: female patients with saline priming; group F2: female patients with priming atracurium dose of 0.05 mg/kg. General anesthesia was induced with midazolam(0.1 mg*kg(-1)) propofol(0.75 mg*kg(-1)), intubation dose of atracurium (0.5 mg*kg(-1)), fentanyl (3 μg*kg(-1)). The incidences of dizziness, diplopia, heavy eyelids and dyspnea were observed. Neuromuscular tension was quantified by using TOF-Guard neuromuscular monitor, and intubating time was defined as the duration from the infusion of intubation dose of atracurium to the time when T4/T1=0. The intubating time of group F2 was shorter than that of group F1. There was no significant difference between group M1 and group M2. The incidences of dizziness, diplopia and heavy eyelids in group F2 were higher than those in group M2. Atracurium priming technique could shorten the intubation time of female patients, but not for male patients, and the gender plays a key role in affecting the clinical outcome of atracurium priming.

Nuclear Donor Cell Lines Considerably Influence Cloning Efficiency and the Incidence of Large Offspring Syndrome in Bovine Somatic Cell Nuclear Transfer

Total five ear skin fibroblast lines (named F1, F2, F3, F4 and F5) from different newborn Holstein cows have been used as nuclear donor cells for producing cloned cows by somatic cell nuclear transfer (SCNT). The effects of these cell lines on both in vitro and in vivo developmental rates of cloned embryos, post-natal survivability and incidence of large offspring syndrome (LOS) were examined in this study. We found that the different cell lines possessed the same capacity to support pre-implantation development of cloned embryos, the cleavage and blastocyst formation rates ranged from 80.2±0.9 to 84.5±2.5% and 28.5±0.9 to 33.3±1.4%, respectively. However, their capacities to support the in vivo development of SCNT embryos showed significant differences (p<0.05). The pregnancy rates at 90 and 240day were significantly lower in groups F2 (4.9% and 3.3%) and F3 (5.4% and 5.4%) compared to groups F1 (23.3% and 16.3%), F4 (25.7% and 18.6%) and F5 (25.9% and 19.8%) (p<0.05). The cloning efficiency was significantly higher in group F5 than those in group F1, F2, F3 and F4 (9.3% vs 4.1%, 1.2%, 2.0% and 5.0%, respectively, p<0.05). Moreover, large offspring syndrome (LOS) incidence in group F5 was significantly lower than those in other groups (p<0.05). All cloned offspring from cell line F1, F2, F3 and F4 showed LOS and gestation length delay, while all cloned offspring from F5 showed normal birthweight and gestation length. We concluded that the nuclear donor cell lines have significant impact on the in vivo development of cloned embryos and the incidence of LOS in cloned calves.

How does the Serum Catecholamine Change and Post Transplant Renal Function

Objective: To keep different levels of blood pressure and to observe the effects on the posttransplant renal function under general anesthesia. Methods: We selected 20 patients with the renal normal function (group N, n=20) who undergoing live donor nephrectomy under general anesthesia; the renal failure group (group F n=20) who undergoing renal transplantation. Blood pressure, ECG, SpO2, PETCO2, BIS were monitored continuously. Levels of norepinephrine, epinephrine, aldosterone in blood plasma were measured before anesthesia, after anesthesia before skin incision, at the time point of kidney exploration and after nephrectomy 10 min,40 min,120 min or at the renal vascular anastomosis opened for 10 min, 40 min, 120 min and even for 1st, 3rd days after kidney transplant. Meanwhile, we detected the volume of urine, serum concentrations of Cr (Creatinine), BUN (Blood urea nitrogen), cystsin C (CysC) and β2 microglobulin (β2-MG) for group F1(using the vasoactive drug to maintain the SBP 160-140 mmHg) and group F2 (SBP was kept at 139-110 mmHg) at different time points during the donor’s kidney was transplanted. Results: 1. Aldosterone was increased significantly at kidney exploration or the renal vascular anastomosis, comparied to pre-induction (P<0.05). But, there were no difference between two groups at each time points. 2. The volume of urine was increased as the time going on after kidney replacement in group F1 and F2. Meanwhile, The serum concentrations of Cr, BUN, CysC and β2-MG were decreased at the T4,T5,1st, 3rd time points, But there were no difference between F2 and F2 groups at each time point. Conclusion: The renin angiotensin aldosterone system was active in renal function normal or failure patients in peri-operation. And the transplanted kidney could work well under the physiologic levels of blood pressure and the higher SBP might not be essential in the renal failure patients.

Influência da icterícia colestática na variação ponderal em modelo experimental

To evaluate the influence of cholestatic jaundice in weight variation. We used 64 adult rats divided into six groups: F1 (n = 6): normal females; F2 (n = 6): laparotomy females; F3 (n = 20): jaundiced females; M1 (n = 6): normal males; M2 (n = 6): laparotomy males; M3 (n = 20): jaundiced males. Jaundice was obtained by ligation and section of the biliopancreatic duct. The animal weights were recorded weekly for seven weeks. On the 14th day of the experiment, bilirubin and gonadal hormones were assessed. After the seventh week a histological study of the liver was performed. The animals in groups F3 and M3 showed elevated bilirubin and decreased body mass when compared to the other groups. The weight differences were significant from the fourth week on amongst females and from the fifth in males. In Jaundiced animals there was increased estradiol and decreased progesterone and testosterone. Perivenular septa and periportal fibrosis, cholangitis and bile duct hyperplasia occurred in the liver of jaundiced rats. No animal showed cirrhosis. There was decrease in murine body weight in the presence of cholestatic jaundice in both genders.

Comparison of effects of fentanyl, sufentanil and remifentanil on immune function of dendritic cells in human umbilical cord blood

Objective To compare the effects of fentanyl,sufentanil and remifentanil on the immune function of dendritic cells in human umbilical cord blood.Methods Human umbilical cord blood mononuclear cells were obtained by density gradient centrifugation and seeded in 24-well plates with a density of 1 × 106/ml (2ml/hole).The cells were randomly divided into 7 groups (n =15 each):control group (group C),fentanyl 1.0 ng/ml group (group F1),fentanyl 5.0 ng/ml group (group F5),sufentanil 0.1 ng/ml group (group S1),sufentanil 0.5 ng/ml group (group S5),remifentanil 1.0 ng/ml group (group R1),and remifentanil 5.0 ng/ml group (group R5).The cells were incubated for 10 days in serum-free culture medium containing 50 ng/ml recombinant human granulocyte colony stimulating factor,10 ng/ml recombinant human interleukin-4 or the corresponding concentration of fentanyl,sufentanil or remifentanil,and then 50 ng/ml recombinant human tumor necrosis factor alpha was added to the culture medium and the cells were incubated for another 4 days in the seven groups.Three holes in each group were chosen and the cell morphology was examined with inverted microscope.Six holes in each group were chosen for determination of the concentration of IL-12 in the supernatant and expression of CD80/CD86.Six holes in each group were chosen for measurement of the cell viability.Results Compared with group C,the concentration of IL-12 and cell viability were significantly decreased and the expression of CD80/CD86 was down-regulated in groups F5,S1,S5,R1 and R5 (P ＜ 0.05).The concentration of IL-12,cell viability and expression of CD80/CD86 were significantly lower in groups S1 and R1 than in group F1 (P ＜ 0.05).Compared with group F5,the concentration of IL-12 was significantly decreased in group S5,and the concentration of IL-12 and cell viability were significantly decreased and the expression of CD80/CD86 was down-regulated in group R5 (P ＜ 0.05).The concentration of IL-12 and cell viability were significantly lower in group R1 than in group S1 (P ＜ 0.05).The concentration of IL-12,cell viability and expression of CD80/CD86 were significantly lower in group R5 than in group S5 (P ＜ 0.05).Conclusion Remifentanil has stronger inhibitory effect on the immunological function of dendritic cells in human umbilical cord blood than sufentanil,and the inhibitory effect of sufentanil is stronger than that of fentanyl. Key words: Fentanyl; Sufentanil; Piperidines; Immunity, cellular; Dendritic cells

Effects of different concentrations of propofol on apoptosis in hippocampal neurons in neonatal rats in vitro

Objective To investigate the effects of different concentrations of propofol on the apoptosis in hippocampal neurons in neonatal rats in vitro.Methods Primary hippocampal neurons were prepared from newborn Sprague-Dawley rats (aged 7 days) and cultured for 7 days.The neurons were randomly divided into 7 groups (n =8 each):control group (group C),propofol 4,8 and 12 μg/ml groups (groups P1-3),and fat emulsion 4,8and 12 μg/ml groups (groups F1-3).The cells were cultured for 24 h in the culture medium containing propofol 4,8 and 12μg/ml in groups P1-3,respectively.The cells were cultured for 24 h in the culture medium containing fat emulsion 4,8 and 12 μg/ml in groups F1 3,respectively.The cell morphology was examined by microscopy after 24 h culture.The expression of caspase-3 (by immuno-histochemistry) and neuronal apoptosis were detected.The neuronal apoptosis rate was calculated.Results Compared with group C,the neuronal apoptosis rate and caspase3 expression were significantly increased in groups P1-3 (P ＜ 0.05 or 0.01).The neuronal apoptosis rat and caspase-3 expression were increased in a concentration-dependent manner in groups P1-3 (P ＜ 0.05).The neuronal apoptosis rate and caspase-3 expression were significantly lower in groups F1-3 than in groups P1-3 (P ＜ 0.05).There was no significant difference in the neuronal apoptosis rate and caspase-3 expression between groups F1-3 (P ＞ 0.05).The damage to neurons was induced in groups P1-3 and most severe in group P3.Conclusion Propofol can promote the apoptosis in hippocampal neurons in neonatal rats in vitro in a concentration-dependent manner. Key words: Propofol; Hippocampus; Neurons; Apoptosis; Infant, newborn

ASSESSMENT THE PAPILLARY MUSCLE FUNCTION OF FUNCTIONAL MITRAL REGURGITATION USING SPECKLE TRACKING TECHNOLOGY

ObjectivesTo evaluate the function of left-side papillary muscles (PM) in ischaemic and non-ischaemic cardiomyopathy patients (ICM, NICM) with functional mitral regurgitation (FMR).MethodsEighty control subjects were enrolled (group H). Sixty ICM...

Effects of different doses of fentanyl on brain areas activated by pain: evidence from functional magnetic resonance imaging

Objective To investigate the effects of different doses of fentanyl on pain-activated brain areas as demonstrated by functional magnetic resonance imaging (fMRI) at 3.0 T.Methods Twenty healthy right-handed male volunteers aged 20-40 yr were randomly divided into 2 groups ( n =10 each); group F1 (fentanyl 1.0 μg/kg) and group F2 (fentanyl 1.5 μg/kg).Mechanical stimulation with von Frey filaments (vFFs,300 g) was delivered to left sole.The intensity of pain was assessed by VAS scores.fMRI was performed before and after fentanyl administration and the changes in the brain areas activated by pain were recorded.Results In group F1 ipsilateral (left) cingulate gyrus was activated after a bolus of fentanyl 1.0 μg/kg under stimulation with vFFs 300 g,while in group F2 bilateral cingulate gyrus and contralateral (right) insula were activated under vFFs stimulation after fentanyl 1.5 μg/kg.Conclusion Cingulate gyrus and insula may be the target brain areas of fentanyl analgesia. Key words: Fentanyl; Analgesia; Brain; Magnetic resonance imaging

Effect of Iron II on Hydroxyapatite Dissolution and Precipitation in vitro

The aim of this study was to evaluate the effect of iron II on the dissolution and precipitation of synthetic hydroxyapatite (HA). HA powder was suspended in solutions of iron (0.84 µg/ml, Fe0.84; 18.0 µg/ml, Fe18; 70.0 µg/ml, Fe70), fluoride (1,100 µg/ml, F1,100), and deionized water and submitted to pH cycling. After pH cycling, the samples were analyzed by infrared spectroscopy and X-ray diffraction. The concentrations of fluoride, calcium, phosphorus, and iron were also analyzed. The data were submitted to ANOVA, and analyzed by Tukey’s test (p < 0.05). The infrared spectrum showed a reduction in all bands corresponding to phosphates and hydroxyls and an increase in the carbonate band in the groups with iron. The intensity of the phosphate bands increased and that of the hydroxyl bands decreased in the group F1,100. It was observed that there was a higher concentration of Ca in the group F1,100, with no significant difference between the groups Fe18 and Fe70 (p > 0.05). There was an increase in Fe concentration in the HA directly related to the Fe concentration of the treatment solutions. Results show that the presence of Fe causes the precipitation of apatite with high solubility.

Low temperature thermoelastic and structural properties of LaGaO3 perovskite in the Pbnm phase

The thermoelastic and structural properties of LaGaO3 perovskite have been studied using high resolution neutron diffractometry at 158 temperatures between 11K and 548K. Data collected in 2K intervals between 410K and 430K show no evidence for an intermediate phase between the low temperature phase in space group Pbnm and the high temperature phase in space group F3¯2/n. From a simultaneous fit of the unit cell volume and the isochoric heat capacity, the phonon density of states in the Pbnm phase is shown to be approximated by a two-term Debye model, with characteristic temperatures 294(1)K and 831(1)K. Vibrational Debye temperatures, determined from fitting the temperature variation of the atomic displacement parameters, show the cations to be more associated with the lower characteristic temperature, whilst that for the anions, is closer to the higher characteristic temperature. Structural parameters are presented as the amplitudes of the seven symmetry-adapted basis-vectors of the aristotype phase, and a structural basis for the temperature-dependence of the bond lengths is outlined. The phase transition in both temperature and pressure arises when a non-bonded La–O distance approaches the La coordination sphere.

Evaluación in vitro de la resistencia compresiva de un sellante resinoso fluorado pre y post liberación de flúor

Aim: To evaluate in vitro compressive strength of fluoride-containing resin-based sealant (F) before and after fluoride release in water. Materials and Methods: We used 40 specimens with 6 mm of height and 20 mm of diameter using fluoride-containing resin-based sealant (FluroShield,Brasil, Dentsply) and non-fluoride-containing resin-based sealant (Concise (TM) Light Cured White Sealant, USA, 3M ESPE). The specimens were divided into four groups, two fluoride-containing resin-based sealants (F1 and F2) and two like control groups (C1 and C2). A group of specimens of fluoride-containing resin-based sealant and a control group (F1/C1) remained without exposure to water, while other groups (F2/C2) were immersed in distilled water for 30 days. The release of fluoride from the F2 was measured through selective electrode method on days 1, 2, 3 and 30. Subsequently, the compressive strength was measured using a universal testing machine (Lloyd, LR 100, UK) with a crosshead speed of 1 mm/min. Comparisons between groups F1 vs F2 and C1 vs C2 were analyzed with t-Student. The significance level was set at 0.05. Results: The compressive strength (Mpa) before and after immersion in water for fluoride-containing resin-based sealant was 337.2 and 337.4, while the control sealant was 203.8 and 213.4. For both groups the observed differences were not significant. The initial fluoride release was 1.9 ppm during the first 24 hours and then declined to 0.0 ppm during the third day of release. Conclusion: In this in vitro study, the release of fluoride from a fluoride-containing resin-based sealant does not affect compressive strength.

Evaluación in vitro de la resistencia compresiva de un sellante resinoso fluorado pre y post liberación de flúor

AimTo evaluate in vitro compressive strength of fluoride-containing resin-based sealant (F) before and after fluoride release in water. Materials and MethodsWe used 40 specimens with 6mm of height and 20mm of diameter using fluoride-containing resin-based sealant (FluroShield,Brasil, Dentsply) and non-fluoride-containing resin-based sealant (Concise (TM) Light Cured White Sealant, USA, 3M ESPE). The specimens were divided into four groups, two fluoride-containing resin-based sealants (F1 and F2) and two like control groups (C1 and C2). A group of specimens of fluoride-containing resin-based sealant and a control group (F1/C1) remained without exposure to water, while other groups (F2/C2) were immersed in distilled water for 30 days. The release of fluoride from the F2 was measured through selective electrode method on days 1, 2, 3 and 30. Subsequently, the compressive strength was measured using a universal testing machine (Lloyd, LR 100, UK) with a crosshead speed of 1mm/min. Comparisons between groups F1 vs F2 and C1 vs C2 were analyzed with t-Student. The significance level was set at 0.05. ResultsThe compressive strength (Mpa) before and after immersion in water for fluoride-containing resin-based sealant was 337.2 and 337.4, while the control sealant was 203.8 and 213.4. For both groups the observed differences were not significant. The initial fluoride release was 1.9ppm during the first 24 hours and then declined to 0.0ppm during the third day of release. ConclusionIn this in vitro study, the release of fluoride from a fluoride-containing resin-based sealant does not affect compressive strength.

Influence of the menstrual cycle on the incidence of nausea and vomiting after laparoscopic gynecological surgery: a pilot study

Study ObjectiveTo investigate whether the phase of menstrual cycle influences the incidence of postoperative nausea and vomiting (PONV) in women undergoing general anesthesia for elective laparoscopic gynecological surgery. DesignProspective, observational, blinded study. SettingGeneral hospital, Postanesthesia Care Unit, and gynecologic floor room. Patients111 ASA physical status 1 and 2 women, aged 18 to 53 years. InterventionsPatients were classified into three groups according to the phase of menstrual cycle at the time of anesthesia: Group F1: follicular phase (menstrual days 1-8; n = 34); Group O2: ovulatory phase (days 9-15; n = 40); and Group L3: luteal phase (days 16 to end of cycle; n = 37). Anesthetic, postoperative pain management, and antiemetic regimens were standardized. MeasurementsFrequency of nausea, vomiting, or both were assessed for early (0-2 hrs). Late PONV (2-24 hrs) along with the use of rescue antiemetic, severity of nausea, and pain. Main ResultsIn the follicular (n = 34), ovulatory (n = 40) and luteal phase (n = 37) groups, the frequencies of PONV over 24 hours were 35%, 38%, and 14% (P = 0.04), respectively. This was due to differences in the early postoperative period where the frequencies were 21%, 25%, and 3% (P = 0.02), respectively, as frequencies were similar in the late period (15%, 20% and 14%, P = 0.71), respectively. Nausea scores, rescue antiemetic usage, pain scores, and opioid consumption were similar in the groups. ConclusionPatients in the luteal phase of their menstrual cycle may have a decreased risk of PONV after laparoscopic gynecological surgery in the early postoperative period.