Force and moment measurement capabilities are quintessential in wind tunnel testing. A force and moment balance had never been tested in the BAM6QT before this research. The work accomplished in this ...thesis performed the first force and moment testing in the BAM6QT and laid the groundwork for a better balance to be acquired in the near future. The BAM6QT is a quiet tunnel, meaning it is capable of low disturbance freestream flow. This feature makes it ideal for research in boundary layer transition. The intersection of hypersonic aerodynamic loading and the effects of freestream noise on the boundary layer will create many opportunities for new research. The BAM6QT will be the only hypersonic quiet tunnel with force and moment capabilities. Having the right balance for the conditions in the BAM6QT is imperative for successful implementation. Many types of force and moment balances exist and are explained in the introduction of this work. A 6-component, internal strain gauge balance was loaned from Calspan to facilitate this research. The strain gauge balance is a type well suited for conventional tunnels. The research explored if the general purpose nature of the strain gauge balance would be suitable for the BAM6QT. A BAM6QT run lasts 4 to 6 seconds and is comprised of several intervals of steady stagnation pressure near 190 ms in duration. In test durations below 200 ms, strain gauge balances decrease in accuracy without the use of acceleration compensation. It was sought to determine if the BAM6QT tunnel would require acceleration compensation to achieve load measurements. This would be the case if each interval incurred an impulse of inertial loads with a low enough frequency to not be filtered out before the next impulse. For five components: Normal force (NF), pitching moment (PM), side force (SF), yawing moment (YM), and rolling moment (RM), it was not found that acceleration compensation was required. Low frequency inertial loads were not apparent. In the tracking of cone and tunnel movement via high speed video, no low frequency vertical movement was identified. Axial force (AF) was inconclusive. A consistent 5.3 Hz oscillation was present in AF running loads. This frequency is the same as the frequency of quasi-steady intervals resulting from the expansion fan reflection in the driver tube. Tunnel movement was detected at the frequency. However, the movement was not large enough to cause inertial loads comparable to the amplitude of oscillation. If this is an oscillation in aerodynamic loading, acceleration compensation would be of little gain. A balance must operate within an established load range or risks damage. Error in the balance measurements is proportional to the maximum load range. Because the startup loads of the BAM6QT were suspected to be large but were unknown, a balance with a substantial load range was selected to provide a large factor of safety. The cost of the large load range was increased measurement error. Running loads were near 1% or less of the maximum load range. The bias and precision error of the balance was a larger than the magnitude of the running load for all but AF. Bias error for the low range was estimated from bench-top testing and was significantly lower than the bias error over the full range.
By positional cloning, we identified two breakpoint-spanning genes in a familial clear cell renal cell carcinoma (CCRCC)-associated t(1;3)(q32.1;q13.3):
LSAMP and
NORE1 (
RASSF1 homolog). Both genes ...are downregulated in 9 of 9 RCC cell lines. While the
NORE1A promoter predominantly presents partial methylation in 6 of the cell lines and 17/53 (32%) primary tumors, the
LSAMP promoter is completely methylated in 5 of 9 cell lines and in 14/53 (26%) sporadic and 4 familial CCRCCs. Expression of LSAMP and NORE1A proteins in CCRCC cell lines inhibited cell proliferation. These characteristics indicate that LSAMP and NORE1A may represent new candidate tumor suppressors for CCRCC.
Endothelial cell loss after 4 mm cataract surgery Lavery, Kevin T.; McDermott, Mark L.; Ernest, Paul H. ...
Journal of cataract and refractive surgery,
05/1995, Letnik:
21, Številka:
3
Journal Article
Recenzirano
To assess whether a 4 mm scleral tunnel incision with a 1.5 mm internal corneal lip (three-step procedure) causes increased endothelial cell loss and damage to the cornea, we retrospectively ...evaluated the outcomes of 20 patients (40 eyes) who had a standard 4 mm scleral tunnel incision (two-step procedure) in one eye followed by a three-step incision in the second eye, with in situ phacoemulsification and insertion of a foldable silicone lens in each eye. Mean phacoemulsification time was 2.4 ± 1.1 minutes for the two-step incisions and 3.4 ± 1.4 minutes for the three-step incisions. Preoperative and postoperative endothelial cell counts were obtained to determine the effects of surgery on the corneal endothelium. Although the three-step procedure had a trend toward increased endothelial cell loss from the central corneal region compared with the two-step incision, the result was neither clinically nor statistically significant. The difference between the three-step and two-step incisions in postoperative endothelial cell counts from the superior corneal region was statistically significant. The difference in postoperative counts from the inferior region was not statistically significant. Although the three-step 4 mm incision does seem to affect the corneal endothelium, its clinical significance is unknown.
Hep G2 cells were used to study the synthesis and secretion of phospholipid transfer protein (PLTP). Upon incubation of the cells at confluence with serum-free Dulbecco's modified Eagle's medium ...(DMEM), phosphatidylcholine (PC) transfer activity was found to accumulate in the culture media. The PC transfer activity in the media was effectively inhibited by rabbit anti-human PLTP immunoglobulin (Ig)G, thus indicating that the PC transfer activity was due to secreted PLTP. The molecular weight of Hep G2 PLTP was approximately 78 kDa by Western blot analysis, in agreement with the molecular weight obtained for purified human plasma PLTP. The PLTP secreted by Hep G2 also possessed an HDL conversion activity similar to that of human plasma PLTP. The addition of butyrate to the cell culture media resulted in a marked increase in the secretion of PLTP. After 24 h incubation with 4 mmol/L sodium butyrate, a more than twofold increase (P < 0.01) of PC transfer activity in the cell-conditioned media was obtained. The dose-dependent increase in the PC transfer activity in the media upon butyrate treatment was well correlated (r = 0.80, P < 0.01) with that of PLTP mass as determined by immuno-slot blot analysis of cell-conditioned media. The increased secretion of PLTP by Hep G2 treated with sodium butyrate was accompanied by a greater increase in the level of PLTP mRNA in the cells as determined by ribonuclease protection assay. In the presence of 4 mmol/L sodium butyrate, a fourfold increase (P < 0. 01) in mRNA level was obtained at 24 h. No stabilizing effect of butyrate on PLTP mRNA was apparent upon treatment of the cultured cells with the RNA synthesis inhibitor, actinomycin D. Thus, the up-regulatory effect of butyrate on PLTP gene expression seemed to have occurred at the transcriptional level.
Thirty nine 3-person groups were asked to make a series of 36 judgments regarding the probability that hypothetical high school dropouts would return to school. These judgments were based on a set of ...information, part of which was given to all group members prior to discussion (shared information) and part of which was divided among them (unshared information). Results suggest that group accuracy was determined by how accurate members were prior to discussion and that the vital role of group discussion was not to exchange information but to aggregate member judgments into a consensual group judgment. (Original abstract - amended).
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
We studied 40 eyes from patients with pre-existing corneal endothelial cell dystrophy (endothelial cell counts of less than or equal to 1,200/mm2) to assess whether the scleral tunnel incision with ...internal corneal lip and phacoemulsification in situ procedure affected the cornea. Identification of endothelial cell dystrophy by measuring preoperative endothelial cell counts was important so minor modifications of decreased phacoemulsification power and frequent viscoelastic endothelial coating could be made to prevent damage to the eyes. The procedures had no effect on corneal thickness or endothelial cell counts. Only about one fourth of the eyes studied (11) had more than 10% endothelial cell loss; none of the 11 eyes showed clinical evidence of corneal decompensation. All patients without other underlying pathologies such as macular degeneration attained postoperative visual acuity of at least 20/40. The scleral tunnel incision with internal corneal lip and phacoemulsification in situ procedure, with minor modifications, is safe in patients with endothelial cell dystrophy of the cornea.
The U.S. EPA （Environmental Protection Agency） established the CASTNET （Clean Air Status and Trends Network） and its predecessor, the NDDN （national dry deposition network）, as national air quality ...and meteorological monitoring networks. Both CASTNET and NDDN were designed to measure concentrations of sulfur and nitrogen gases and particles. Both networks also estimate dry deposition using an inferential model. The design was based on the concept that atmospheric dry deposition flux could be estimated as the product of a measured air pollutant concentration and a modeled deposition velocity （Vd）. The MLM （multi-layer model）, the computer model used to simulate dry deposition, requires information on meteorological conditions and vegetative cover as model input. The MLM calculates hourly Fa for each pollutant, but any missing meteorological data for an hour renders Vd missing for that hour. Because of percent completeness requirements for aggregating data for long-term estimates, annual deposition rates for some sites are not always available primarily because of missing or invalid meteorological input data. In this work, three methods for replacing missing on-site measurements are investigated. These include （1） using historical values of deposition velocity or （2） historical meteorological measurements from the site being modeled or （3） current meteorological data from nearby sites to substitute for missing inputs and thereby improve data completeness for the network＇s dry deposition estimates. Results for a CASTNET site used to test the methods show promise for using historical measurements of weekly average meteorological parameters.
The U.S. Environmental Protection Agency Clean Air Status and Trends Network (CASTNET) utilizes an open-face filter pack system to measure concentrations of atmospheric sulfur and nitrogen species. ...Concentration data for nitrogen species measured with filter packsystems sometimes deviate from data collected by other measurement systems used to measure the same species. The nature of these differences suggests that more than one sampling mechanism or atmospheric process is involved. The study presented here examines these differences by intercomparing CASTNET data with data from other studies, examining the results from earlier intercomparison studies, and conducting a field test to investigate the effect of particle size on filter pack measurement systems. Measurements of nitrogen species from the Maryland Aerosol Research and Characterization (MARCH) monitoring site were compared with nitrogen concentrations at three nearby CASTNET sites. Results indicate thatCASTNET measured higher paniculate nitrate (N03 -) and lower gaseous nitric acid (HN03)concentrations Comparisons of NO3 - from 34 collocated CASTNET and Interagency MonitoringofProtected Visual Environments (IMPROVE) sites show that CASTNET NO3 - measurements were typically higher than the corresponding IMPROVE values Also, results from the Lake Michigan Air Director's Consortium Midwest Ammonia Monttonng Project demonstrated NO3 - dissociation on Teflon filters To investigate the effect of particle size, filter pack measurement systems were operated at three CASTNET sites with and without cyclones dunng six 7-day measurement penods from March to August 2006. Results indicate the size-selection cyclones had a significant effect on both NO3 - ana HNO3 concentrations but little effect on sulfate (S04 2-) and ammonium (NH4 + levels NO3 - concentrations sampled with the open-face filters were significantly higher than concentrations measured with a 2.5- m cut point, as were HN03 concentrations. Although limited in spatial and temporal coverage, the fieldstudy showed that the use of an open-face filter pack may allow for the collection of coarse NO3 - particles and for the reaction of HNO3 with metals/ salts on the Teflon filter.
PDF
