Disk Depth Research Articles

Troponin T Elevation After Percutaneous Left Atrial Appendage Occlusion.

Background: Cardiac troponin T (cTNT) has been widely used in detecting cardiac damage. Elevated cTNT level has been reported to be associated with increased mortality in multiple cardiac conditions. It is not uncommon to observe an increased level of cTNT in patients after left atrial appendage occlusion (LAAO). The objective of the study is to study the incidence, significance, and factors associated with cTNT elevation after LAAO.Methods: We prospectively included patients who underwent LAAO from January 2019 to July 2020 in Fudan Zhongshan Hospital. Patients were divided into those with elevated cTNT after procedure and those with normal postprocedure cTNT. All individuals were followed up for 1 year. The primary outcome is major adverse cardiovascular events, which include myocardial infarction, heart failure, cardiac death, and stroke. The second outcome is periprocedure complication, including chest pain, tachycardia, cardiac tamponade, change of electrocardiograph, and atrial thrombus.Results: A total of 190 patients were enrolled. Of the patients, 85.3% had elevated cTNT after LAAO, while 14.7% of them did not. Exposure time, dosage of contrast, types of devices, shapes, and sizes of LAA could contribute to elevated postprocedure cTNT. We found that patients with a Watchman device were more likely to have elevated postprocedure cTNT than those with a Lambre device (89.2 vs. 76.7%, p = 0.029). LAAO shapes were associated with cTNT levels in patients with a Watchman device, while the diameter of the outer disc and LAA depth mattered for the Lambre device. There was no significant difference in the primary and second outcome between the two groups (p-value: 0.619, 0.674).Conclusion: LAAO was found to be commonly accompanied with cTNT elevation, which might not to be related to the complications and adverse cardiac outcomes within 1 year of follow-up. Moreover, eGFR at baseline, exposure time, dosage of contrast, types of LAAO device, and LAA morphology could contribute to cTNT elevation.

Integrated Design and Evaluation of a Soil-Covering and Film-Mulching Device for Sugarcane Transverse Planters

To solve the problem that the covering device of sugarcane cannot be adequate for the agronomic standards of seed cane setts planting, a soil-covering and film-mulching device for sugarcane transverse planting was designed. The device includes a soil-covering part, soil-compacting part, and film-mulching part. Through theoretical analysis of key components, the factors affecting the cane seed covering quality for the device were obtained. A quadratic orthogonal rotation regression test was conducted by a homemade prototype to explore the effects of disk diameter, central distance, disk depth in soil, and dip angle on soil covering thickness. The results showed that the above factors all have an extremely significant effect on the soil covering thickness, and the effect degree of each factor from high to low is central distance, disk depth in soil, dip angle, and disk diameter within the range of test parameters. The optimal parameter combination, with the disk diameter, the dip angle, the central distance, the disk depth in soil, and the diameter of the soil-compacting wheel being 304.7 mm, 55.1°, 386.5 mm, 32.4 mm, and 300 mm, respectively, was obtained by Design-Expert software and verified by comprehensive field tests. The results showed that the covering thickness is in the range of 94–111 mm, the average value is 102.6 mm, and the breakage rate is no more than 2.6%. The emergence rate is 86.4%, which is an improvement of 9.3% over that of a traditional covering device. The results suggested that the device can conform to the agricultural covering standard of sugarcane planting and provide a design basis for the application and popularization of the soil-covering and film-mulching device.

Prediction of Lumbar Disc Bulging and Protrusion by Anthropometric Factors and Disc Morphology.

The relationship between reduced disc height and disc bulging and/or protrusion has been controversial. The purposes of this study were to examine the relationship between disc morphology and disc bulging and protrusion and to establish a model for predicting disc bulging and protrusion. This is a retrospective study. A total of 452 MRI scans from a spine study were analysed, 210 (46.5%) were men. Logistic regression analysis was applied to identify the association between anthropometric factors, disc morphology factors, and outcome. Model 1 was constructed using anthropometric variables to investigate the capacity for predicting outcomes. Model 2 was constructed using anthropometric and disc morphology variables. Age, body weight, body height, disc height, and disc depth were significantly associated with outcome. The area under the curve (AUC) statistics of Model 2 were significantly better than those of Model 1 at the L3-L4 and L4-L5 levels but not at the L5-S1 level. The results showed an association between disc morphology and disc bulging and/or protrusion at the L3-L4, L4-L5, and L5-S1 levels. The model utilizing both anthropometric factors and disc morphology factors had a better capacity to predict disc bulging and/or protrusion compared with the model using only anthropometric factors.

Anatomic Study of Anterior Transdiscal Axial Screw Fixation for Subaxial Cervical Spine Injuries.

Anterior transdiscal axial screw (ATAS) fixation is an alternative or supplement to the plate and screw constructs for the upper cervical spine injury. However, no existing literatures clarified the anatomic feasibility of this technique for subaxial cervical spine. Therefore, the objective of this study was to evaluate the anatomical feasibility and to establish guidelines for the use of the ATAS fixation for the subaxial cervical spine injury.Fifty normal cervical spines had radiographs to determine the proposed screw trajectory (the screw length and insertion angle) and the interbody graft-related parameters (the disc height and depth, and the distance between anterior vertebral margin and the screw) for all levels of the subaxial cervical spine. Following screw insertion in 8 preserved human cadaver specimens, surgical simulation and dissection verified the feasibility and safety of the ATAS fixation.Radiographic measurements showed the mean axial screw length and cephalic incline angle of all levels were 41.2 mm and 25.2°, respectively. The suitable depth of the interbody graft was >11.7 mm (the distance between anterior vertebral margin and the screw), but <17.1 mm (disc depth). Except the axial screw length, increase in all the measurements was seen with level up to C5–C6 segment. Simulated procedure in the preserved specimens demonstrated that ATAS fixation could be successfully performed at C2–C3, C3–C4, C4–C5, and C5–C6 levels, but impossible at C6–C7 due to the obstacle of the sternum. All screws were placed accurately. None of the screws penetrated into the spinal canal and caused fractures determined by dissecting the specimens.The anterior transdiscal axial screw fixation, as an alternative or supplementary instrumentation for subaxial cervical spine injuries, is feasible and safe with meticulous surgical planning.

Long-Term Follow-Up of Scanning Laser Polarimetry and Confocal Scanning Laser Ophthalmoscopy in Normal Tension Glaucoma

Background: To investigate the potential of optic nerve head measurements using confocal scanning laser ophthalmoscopy (CSLO) and nerve fiber layer images by means of scanning laser polarimetry (SLP) in the longterm follow-up of normal tension glaucoma (NTG). Methods: Retrospective study of 49 NTG patients with an average age of 65.5 years that have been followed for about 5 years. The long-term change of various parameters of perimetry, CSLO and SLP was examined for all patients. In addition patients were classified according to their Aulhorn glaucoma classification score as beginning (AGS<3) or advanced (AGS ≥ 3) and progressive and non-progressive NTG trying to reveal differences of the parameters in stage and time. Results: Intraocular pressure (IOP), mean defect (perimetry), neuroretinal rim and CDR (CSLO) did not show significant changes over the time. In CSLO, average depth and cupping shape were significantly different over the time and between progressive and non-progressive NTG. SLP revealed significant decrease especially in the superior retinal nerve fiber layer (66.1 vs 57.3 μm), but only relative parameters such as NFI, superior ratio and ellipse modulation were different between beginning and advanced NTG. Discussion: Our study points out that especially relative parameters in SLP such as ellipse modulation or NFI and CSLO-values of optic disc steepness and depth might be helpful in the follow-up of glaucoma patients. They show a better correlation to progression of the disease than classical parameters such as MD, IOP, neuroretinal rim or CDR.

Morphometric study of the lumbosacral spine and some of its related angles in Lebanese adult females.

The present study was undertaken to examine the morphometric characteristics of lumbar vertebrae, lumbar intervertebral discs and some important related angles in Lebanese adult females. The subjects of this study were thirty Lebanese adult females aged between 18-22 years. The subjects were selected among students of the faculty of health sciences, Beirut Arab University. Two plain radiographic views for the lumbosacral spine were taken for each subject, an anteroposterior view and a lateral view. Measurements were made directly on the X-ray films using Vernier calliper and were recorded to the nearest tenth of a millimetre. The following measurements were taken for each lumbar vertebra: the anterior height of the body, the posterior height of the body, the horizontal diameter of the pedicle, the vertical diameter of the pedicle, the interpedicular distance, the width (transverse diameter) of the body. Also the anterior height, the posterior height and the anteroposterior diameter (disc depth) of the intervertebral disc were measured. In addition, the following angles were measured: the angle of lumbar lordosis, the lumbosacral angle and the angle of sacral inclination. The mean and standard deviation were calculated and recorded. The results offer a base line reference for normal Lebanese adult females and a guidance to clinicians for the evaluation and management of subjects complaining of low back pain, in order to propose specific preventive or rehabilitation protocols to prevent low back pain as a function of spinal alignment. Moreover, these normal figures could also be of forensic importance because of the observed racial, ethnic and regional variations.

Morphometric Study of The Lumbosacral Spine and Some of Its Related Angles in Lebanese Adult Females

The present study was undertaken to examine medicolegal importance of morphometric characteristics of lumbar vertebrae, lumbar intervertebral discs and some important related angles in adult Lebanese females. The subjects of this study included thirty Lebanese adult females aged between 18-22 years. The subjects were selected among students of the faculty of health sciences, Beirut Arab University. Two plain radiographic views for the lumbosacral spine were taken for each subject (An anteroposterior view and a lateral view). Measurements were made direct from the X-ray films using Vernier calliper and were recorded to the nearest tenth of a millimetre. The following measurements were taken for each Lumbar vertebra: The anterior height of the body, posterior height of the body, horizontal diameter of the pedicle, vertical diameter of the pedicle, interpedicular distance and the width (transverse diameter) of the body. Regarding intervertebral discs, the anterior height, posterior height and anteroposterior diameter of the disc (disc depth) were measured. In addition, the following angles were measured: the angle of lumbar lordosis, lumbosacral angle and angle of sacral inclination. The mean and standard deviation of the above mentioned parameters were calculated and recorded. It is concluded that measurements obtained in this study form a base line figures in normal Lebanese adult females in terms of morphometric measurements in healthy subjects as well as giving guidance to clinicians as being applicable for evaluation and management of subjects complaining of low back pain; not only do these age related normative values help in identifying the underlying cause, but they also direct physicians towards the proper line of treatment. Whether specific preventive modalities or rehabilitation protocols could be instituted to prevent low back pain in subjects with particular spinal alignment remains unclear and should be investigated in future studies. Moreover, these normal figures could also be of forensic importance because of the racial, ethnic and regional variations which have been observed in comparison with previous studies.

Efficiency of extracting stereo-driven object motions

Most living things and many nonliving things deform as they move, requiring observers to separate object motions from object deformations. When the object is partially occluded, the task becomes more difficult because it is not possible to use two-dimensional (2-D) contour correlations (Cohen, Jain, & Zaidi, 2010). That leaves dynamic depth matching across the unoccluded views as the main possibility. We examined the role of stereo cues in extracting motion of partially occluded and deforming three-dimensional (3-D) objects, simulated by disk-shaped random-dot stereograms set at randomly assigned depths and placed uniformly around a circle. The stereo-disparities of the disks were temporally oscillated to simulate clockwise or counterclockwise rotation of the global shape. To dynamically deform the global shape, random disparity perturbation was added to each disk's depth on each stimulus frame. At low perturbation, observers reported rotation directions consistent with the global shape, even against local motion cues, but performance deteriorated at high perturbation. Using 3-D global shape correlations, we formulated an optimal Bayesian discriminator for rotation direction. Based on rotation discrimination thresholds, human observers were 75% as efficient as the optimal model, demonstrating that global shapes derived from stereo cues facilitate inferences of object motions. To complement reports of stereo and motion integration in extrastriate cortex, our results suggest the possibilities that disparity selectivity and feature tracking are linked, or that global motion selective neurons can be driven purely from disparity cues.

洋河水库富营养化发展趋势及其关键影响因素

The Yanghe Reservoir has been the important drinking resource of Qinhuangdao and Beidaihe summer central office.However,in recent decades the water body has been undergoing intense eutrophication,resulting in loss of water quality and increases in the frequency of cyanobacterial bloom outbreak.It almost lost the function as drinking resource during the occurrence of algal bloom.We have analyzed the eutrophication development and its key regulating factors of the reservoir by collecting history materials and monitoring dataset of water quality in 2011.The results showed that the concentrations of total nitrogen(TN),total phosphorus(TP) have been higher continuously than the critical ones of eutrophication during 1990—2011.Algal blooms have almost broken out in August of each year.Based on the monitoring data in August of each year,TN,TP,chlorophyll a(Chl-a) increased significantly since 1990,their concentration increased from 0.72 mg/L,0.029 mg/L,3.35 μg/L in 1990 to 4.25 mg/L,0.103 mg/L,88.5 μg/L in 2011,respectively.Secchi disk depth(SD) decreased significantly,and it was 1.65 m in 1990,while it decreased into 0.3 m in 2011.Trophic state index based on TN(TSITN),TP(TSITP),SD(TSISD) and Chl-a(TSICHL) were also increased rapidly,and from 49.71,52.71,52.78,42.46 in 1990 to 75.33,70.98,77.36 and 74.58 in 2011,respectively.Based on the Carlson-type TSI,the trophic state of the system were mesoeutrophic in 1990 and became hypereutrophic in 2011.There was a good relationship between SD and Chl-a during 1990—2011(R2=0.9186),indicating that algae dominate light attenuation.From May to October in 2011,water temperature(T) varied from 15.7 to 29.2 ℃,with mean(22.75±4.77) ℃;SD was 0.30—4.00 m with mean(1.66±0.98) m;dissolved oxygen(DO) was 5.38—13.58 mg/L with mean(8.91±2.09) mg/L;pH was 8.17—10.92 with mean(8.87±0.78);chemical oxygen demand(CODMn) was 2.06—4.90 mg/L with mean(3.52±0.94) mg/L;total organic carbon(TOC) was 8.26—23.16 mg/L with mean(13.57±3.66) mg/L;TP was 0.0336—0.095 mg/L with mean(0.060±0.014) mg/L;TN was 3.078—6.752 mg/L with(4.713±1.014) mg/L;nitrate nitrogen(NO3-N) was 0.393—2.856 mg/L with mean(1.252±0.788) mg/L;ammoniacal nitrogen(NH4-N) was 0.0077—0.2191 mg/L with mean(0.109±0.070) mg/L;orthophosphate(PO3-P) was 0.0022—0.0096 mg/L with mean(0.0066±0.0022) mg/L;Chl-a was 1.46—136.97 μg/L with mean(27.31±34.99) μg/L.It revealed that the concentration of each factor varied substantially among months.The correlation relationship analysis showed that T,SD,DO,pH,TP,PO3-P,CODMn and TOC have obvious correlation with Chl-a.SD,DO and pH were the results induced by water eutrophication,but not the driving factors,therefore,SD,DO and pH were the major symptom of water quality deterioration induced by algal bloom outbreak.Since the reservoir is situated in northern temperature zone with 2—3 months ice cover,T should be a driving factor of summer blooms.The regression equation of log-transformed values for Chl-a on the other factors was performed and it is presented as below: log(Chl-a) =-1.768+0.058T+0.006SD-0.067DO+0.068pH+0.118TN-0.091NO3-N+1.25NH4-N+2.272TP+11.669PO3-P+0.037CODMn+0.046TOC,R2=0.979.During the outbreak of algal bloom from the middle July to the end of August in 2011,T was 23.5—29.2℃,and the dominant species were Microystis aeruginosa and M.ichthyoblabe that belong to Cyanophyta with cell density of 3.5×106 and 1.4×106 cells/ml,respectively.The Yanghe Reservoir was a typical lake-reservoir with slow water flow and long residence time.In order to prevent the outbreak of algal bloom and improve the function as drinking resource,the nutrient concentrations must be decreased by reducing exogenous and control endogenesis pollution,and simultaneously change hydrodanimic conditions by increasing flow velocity or water exchange speed.

Line of sight depth of the Large and Small Magellanic Clouds

AbstractWe used the red clump stars from the Optical Gravitational Lensing Experiment (OGLE II) survey and the Magellanic Cloud Photometric Survey (MCPS), to estimate the line-of-sight depth. The observed dispersion in the magnitude and colour distribution of red clump stars is used to estimate the line-of-sight depth, after correcting for the contribution due to other effects. This dispersion due to depth, has a range from minimum dispersion that can be estimated, to 0.46 mag (a depth of 500 pc to 10.44 kpc), in the LMC. In the case of the SMC, the dispersion ranges from minimum dispersion to 0.35 magnitude (a depth of 665 pc to 9.53 kpc). The thickness profile of the LMC bar indicates that it is flared. The average depth in the bar region is 4.0 ± 1.4 kpc. The halo of the LMC (using RR Lyrae stars) is found to have larger depth compared to the disk/bar, which supports the presence of an inner halo for the LMC. The large depth estimated for the LMC bar and the disk suggests that the LMC might have had minor mergers. In the case of the SMC, the bar depth (4.90 ± 1.23 kpc) and the disk depth (4.23 ± 1.48 kpc) are found to be within the standard deviations. We find evidence for an increase in depth near the optical center (up to 9 kpc). On the other hand, the estimated depth for the halo (RR Lyrae stars) and disk (RC stars) for the bar region of the SMC is found to be similar. Thus, increased depth and enhanced stellar as well as H i density near the optical center suggests that the SMC may have a bulge.

Remote Sensing of Water Quality for Burullus Lake, Egypt

The objective of this study was to use Landsat Thematic Mapper TM data combined with surface measurements for mapping water quality parameters of Burullus Lake. Water samples were collected in the field at the same time of satellite image acquisition (April, 1997). TM bands 1, 2, 3, 4, 5, 7 and band ratios 1/4, 3/2, 2/1, 4/2, 4/3, 3/4, 7/5 and principal components of TM bands 1-4 (PC1 and PC2) were compared with in situ measurements and laboratory analysis of water samples. The water quality of interest included, Cl−, K+, Na+, soluble reactive phosphorus (SRP), dissolved inorganic nitrogen (DIN), dissolved oxygen (DO), pH, Salinity, Secchi disc and water depth. Also, the percentage of organic matter in bottom sediments and texture (sand, silt, clay) analyses are used in the evaluation processes. Correlation and regression models were developed between each of the water quality parameter measurements and the radiance of image data. Some water quality parameters were significantly correlated with TM radiance data. Subsequently, multiple linear regression models were used to prepare digital cartographic products depicting the water quality over the entire study area.

A segregation mechanism in a vertically shaken bed

Metal disks of different size and density were placed at the bottom of a bed of monodisperse granu- lar material. The system was vibrated sinusoidally in the vertical direction. It was observed that, if the angular ac- celeration of the shaking was slightly greater than that of gravity, the metal disks rose to the top of the bed. This result has been known for over sixty years, but a basic understanding of the mechanism responsible for the rise of the disks is still a subject of debate. Our experiments and theoretical model show that the ascent speed of the disk is proportional to the square root of the disk densi- ty, approximately proportional to the disk size, and is a function of the disk's depth in the bed. We also investi- gated the speed of ascent of the disk as a function of the shaking frequency, fs. We found that the effective friction or drag coefficient, , between the disk and the granular bed, is proportional to a functional form of the frequency: ∝ (fs − fc) −4 , where fc is the critical shaking frequency for the disk to start moving through the bed. We discuss how such a dependency may arise.

Heights of the lumbar intervertebral discs related to age in Turkish individuals.

The present study investigated the changes in the heights and anteroposterior diameters of human intervertebral discs by means of measurements from radiographs, to determine age changes of lumbar intervertebral discs in Turkish people. Measurements of anterior and posterior disc heights and disc depths were made for 200 clinic subjects of different age groups from lateral radiographs. The height of the intervertebral disc increases with aging only in males and the disc depth in both sexes. Our findings generally corroborate previous studies. It is suggested that the different findings from the present study might be peculiar to the society.

Lumbar intervertebral disc heights in normal subjects and patients with disc herniation.

A method for the measurement of intervertebral disc heights from lateral radiographs obtained in controlled conditions was examined for intra- and interobserver errors. The use of a strict criterion for the positioning of marks on the images of the vertebrae was shown to enable reproducible measurements to be made with a maximum error of 0.7 mm. Measurements of anterior and posterior disc heights and disc depths were made for 11 normal subjects and ten male patients with prolapsed intervertebral discs, while standing upright. The level of the prolapsed discs were shown to have reduced height compared with normal before surgery, and further narrowing 3 months after surgery. The unaffected discs of the patients were the same height as those of the controls. The technique is proposed as suitable for the investigation of the effect on intervertebral discs of procedures such as the injection of chymopapain.