Presence of voids after three obturation techniques in band‐shaped isthmuses: a micro‐computed tomography study

Background The objective of the present micro-computed tomography (micro-CT) study was to assess the presence of voids in band-shaped isthmuses obturated using three different filling techniques. Methods Twenty-four artificial molar teeth with a band-shaped isthmus were allocated to three groups (n = 8) for obturation, according to the filling technique: single-cone (SC), continuous wave of condensation (CWC) or lateral condensation (LC). Obturation was performed with gutta-percha (GP) cones and iRoot SP (Innovative Bioceramix, Vancouver, Canada). Post-filling micro-CT scanning was performed. The percentage of filling materials and void volumes were calculated in the isthmus areas and data were analyzed using one-way ANOVA and Tukey tests. Results The mean percentage of void volumes and corresponding filling percentages in the isthmus areas after obturation in the SC groups was 22.98 % ± 1.19 %, 77.02 % ± 1.19 %; in the CWC groups 10.46 % ± 2.28 %, 89.54 % ± 2.28 %; and in the LC groups was 13.14 % ± 1.85 %, 86.86 % ± 1.85 %, respectively. Conclusions In band-shaped isthmus area, the obturation quality of CWC was superior to SC and LC techniques.

Effect of growth ring angle on lateral enlargement of compressed Cryptomeria japonica wood impregnated with polyethylene glycol

The lateral enlargement perpendicular to the compressive direction for small thin boards of Cryptomeria japonica was investigated to evaluate the effects of density and compressive directions to the radial (plane-sawn board) and 45 degrees of tilt to the radial (45º sawn board). Samples were impregnated with 200 and 20,000 molecular weight polyethylene glycol (PEG). The enlargement perpendicular to the fiber direction with deformation was obtained for heartwood and sapwood specimens treated only with PEG20,000. The compression ratio of specimens treated with PEG 20,000 exceeded the void volumes regardless of the wood density. Enlarged specimens of both sapwood and heartwood showed the inflection points in the force-compression ratio curve and no correlation between the compressive directions and lateral enlargement of specimens. In the local area showing the largest deformation, however, a weak positive correlation from plane-sawn boards and weak negative correlation from 45º sawn boards between the angles of compressive direction to growth ring and lateral enlargement were derived. Microfocus X-ray computer tomography in these areas showed the different morphological compressive deformations. The cells in the 45º sawn board were forced out due to each cell moving, whereas the radially arranged ones in the plane sawn board buckled under compression.

Acyloxyacyl hydrolase regulates voiding activity

Corticotropin-releasing factor (CRF) regulates diverse physiological functions, including bladder control. We recently reported that Crf expression is under genetic control of Aoah, the locus encoding acyloxyacyl hydrolase (AOAH), suggesting that AOAH may also modulate voiding. Here, we examined the role of AOAH in bladder function. AOAH-deficient mice exhibited enlarged bladders relative to wild-type mice and had decreased voiding frequency and increased void volumes. AOAH-deficient mice had increased nonvoiding contractions and increased peak voiding pressure in awake cystometry. AOAH-deficient mice also exhibited increased bladder permeability and higher neuronal firing rates of bladder afferents in response to stretch. In wild-type mice, AOAH was expressed in bladder projecting neurons and colocalized in CRF-expressing neurons in Barrington’s nucleus, an important brain area for voiding behavior, and Crf was elevated in Barrington’s nucleus of AOAH-deficient mice. We had previously identified aryl hydrocarbon receptor (AhR) and peroxisome proliferator-activated receptor-γ as transcriptional regulators of Crf, and conditional knockout of AhR or peroxisome proliferator-activated receptor-γ in Crf-expressing cells restored normal voiding in AOAH-deficient mice. Finally, an AhR antagonist improved voiding in AOAH-deficient mice. Together, these data demonstrate that AOAH regulates bladder function and that the AOAH- Crf axis is a therapeutic target for treating voiding dysfunction.

Void Distribution in Zeolite Warm Mix Asphalt Mixture Based on X-ray Computed Tomography

Warm mix asphalt mixtures have the advantages of energy saving, emission reduction and good road performance. Zeolite asphalt mixtures, as a warm mixing technology, have been applied in the world. To understand the warm mix mechanism of zeolite warm mix asphalt mixture, the mesoscale structure of zeolite asphalt is studied. Micro computed tomography (CT) is utilized to obtain the internal structure image of zeolite-modified asphalt and asphalt mixture. The quantity and volume of voids are used as internal void distribution evaluation indexes. The results indicate that with respect to the void distribution in zeolite-modified asphalt, with the increase of temperature, there is an obvious evolution trend of smaller voids to larger voids. With respect to the voids in the zeolite-modified asphalt mixture, the zeolite asphalt mixture is equivalent to hot mix asphalt mixture when it is above 120 °C, while below 120 °C, the maximum and average void volumes increase significantly, making it difficult for the mixture to achieve ideal compaction effect.

On the distribution of urine output in normally cycling women

SummaryIt has been suggested that it is possible to monitor the menstrual cycle by measuring the concentration of urinary reproductive steroids. This neglects the variation in void volume and in urine production rate. In neither case has any systematic analysis been reported previously. Overnight urine samples were collected each day for one complete cycle by 24 women and the void volumes and intervoid times were recorded. The void volume and urine production rate were approximately lognormally distributed and the intervoid time was approximately normally distributed. Using these distributions we consider the implications of the variation in void volume and urine production rate for the comparison of the concentrations of a urinary analyte in two samples.

2429 Optogenetic stimulation of corticotropin-releasing hormone expressing neurons in Barrington’s nucleus recapitulates the social stress voiding phenotype in mice

OBJECTIVES/SPECIFIC AIMS: Voiding postponement is common cause of LUT dysfunction in which children void infrequently with large volumes. This condition is modeled in mice that are subjected to social stress who show decreased voiding frequency and increased voided volumes along with increases in corticotropin-releasing hormone (CRH) expression in Barrington’s nucleus (BN) (i.e., the pontine micturition center). Optogenetics is a technique to selectively stimulate cells or neurons of interest via light activated channel receptors [i.e., channel-2 rhodopsin (ChR2)]. Here we examined the effects of optogenetic manipulation of CRH BN neurons on the in vivo voiding phenotype and urodynamics in awake mice. We hypothesized that stimulating these neurons at higher frequencies (10–50 Hz) would lead to CRH-dependent alterations in voiding phenotype (i.e., larger voided volumes and longer intermicturition intervals. METHODS/STUDY POPULATION: Double transgenic mice expressing ChR2 in CRH cells were generated using the Cre-lox recombinase system and had fiberoptic probes implanted into BN at 8 weeks of age. The mice also underwent simultaneous catheter placement into the bladder for in vivo cystometry. In vivo cystometry before and during optogenetic stimulation at various frequencies was performed 5–7 days postoperatively. Saline was perfused at 10 µL/minute and baseline stable voiding cycles were established. Bladder capacity, threshold pressure, voiding pressure, and voided volume were recorded at baseline and at each optogenetic setting. In some mice, the protocol was repeated in the presence of CRH antagonist (NBI 30775). RESULTS/ANTICIPATED RESULTS: Fiberoptic stimulation (470 nm at 25 and 50 Hz) produced a significant rise in the intermicturition interval, bladder capacities and increased void volumes. This effect was especially pronounced in females in whom bladder capacity and intermicturition interval more than doubled at 50 Hz stimulation. Fluoroscopic images confirmed complete bladder emptying with each void. The increased bladder capacity at higher frequencies (25 and 50 Hz) was CRH-dependent as injection of a CRH antagonist (NBI 30775) blocked the optogenetic effect. Control non-double mice showed no effects from optogenetic stimulation. DISCUSSION/SIGNIFICANCE OF IMPACT: Our results suggest that optogenetic stimulation of CRH-expressing neurons in BN at high frequency (25 and 50 Hz) inhibits micturition and recapitulates the voiding phenotype seen in socially stressed mice (large, infrequent voids). Lower frequencies of optogenetic stimulation (2 and 10 Hz) had no effects on cystometry parameters or voiding phenotype. In addition, females had a greater response to optogenetic stimulation compared with males with larger bladder capacities and longer intermicturition intervals. The changes in voiding phenotype seen were CRH dependent as blockage of the CRH receptor prevented changes in cystometry parameters with optogenetic stimulation. Further elucidation of these and other neural subpopulations in BN are warranted to understand micturition and how it may be manipulated in disease states such as voiding postponement and acute urinary retention.