SEARCH · PubMed Health

Results for “Read depth”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 325 records · Page 18Linked to original sources

PubMed1996

Post-insertion peri-implant tissue assessment: a longitudinal study.

The peri-implant gingivae act as a biological barrier that prevents the ingress of plaque bacteria, oral debris, and saliva components into the internal environment of the jaw. The integrity of this barrier around a total of 163 Steri-Oss HA-coated threaded root-form implants placed in 48 patients was examined at six-month intervals over a 42-month time period, beginning at the time of final prosthetic placement. Five clinical parameters for tissue assessment were used: Mean Implant Sulcus Readings (MISR), Mühlemann Sulcus Bleeding Index (SBI), Miller's Mobility Index (MI), bone loss readings (BL), and gingival condition (GI). Bone loss and mobility were negligible throughout the 42-month study period. At six months post-insertion, 58.6% of the Mean Implant Sulcus Readings exceeded 4 mm. Gingival conditions and bleeding response also were non-ideal in a significant number of cases (52.9 and 62.1%, respectively). However, all three of these assessments later showed dramatic improvement. Patients' inability to "deplaque" their newly acquired implant prostheses effectively may be a factor contributing to the high incidence of undesirable pocket depths and non-optimal gingival appearance at the first six-month assessment point. Attainment of the necessary skills may account for the improved readings at the later evaluations.

Adult↗

PubMed1999

A survey of output intensity and potential for depth of cure among light-curing units in clinical use.

OBJECTIVES: The light intensity of curing lights used in private dental offices was measured using commercial curing and heat radiometers and related to uniformity of cure depth of standardized composite specimens. METHODS: The intensity of 130 curing light from 107 dental offices was measured with curing and heat radiometers. Due to analogue readings, results were recorded in steps of 25 mW cm-2 and assigned a category number. A total of 50 lights were randomly selected to polymerize standardized 3 mm thick composite cylinders. The composite was irradiated for 50 s according to the manufacturer's instructions. The Knoop hardness value was measured at the top and bottom surfaces and the uniformity of cure depth was calculated from the ratio of these two values. RESULTS: Light intensity measured by the curing and heat radiometers was in the range of 25-825 and 0-325 mW cm-2, respectively. Functions of maximum likelihood estimation of the top and bottom surface hardness were 57 N/N + 1.3 and 80 N/N + 17.7, respectively (N = light intensity category number). The relationship between the logarithmic transformation of the hardness ratio and light intensity was linear (R2 = 0.84 p < 0.001). CONCLUSION: According to the manufacturer, a curing light is considered as unsuitable for use with a reading of < 200 mW cm-2 by the curing radiometer and > 50 mW cm-2 by the heat radiometer. Applying these criteria to the present study, 46% of the lights (without repetitions) required repair or replacement. The strong correlation found between the hardness ratio and light intensity verifies the usefulness of the curing radiometer in predicting the polymerization ability of the light activation units.

Composite Resins↗

PubMed1996

Reading vocabulary knowledge and deafness.

With respect to reading vocabulary knowledge and deafness, this article addresses two broad questions: (1) Why is vocabulary knowledge related to reading comprehension ability? (2) How is reading vocabulary (i.e., word meanings) acquired? The article argues that the answers to these questions are best addressed by a vocabulary acquisition model labeled the knowledge model. In essence, this model asserts that both breadth and depth of vocabulary knowledge are critical. It is necessary to teach vocabulary, especially to poor readers, who are not likely to derive many word meanings from the use of context during natural or deliberate reading situations. On the basis of theoretical and research syntheses, the article offers implications for vocabulary instruction for deaf children and adolescents.

Journal Article↗

PubMed1995

Electrical impedance measured to five skin depths in mild irritant dermatitis induced by sodium lauryl sulphate.

The non-invasive electrical impedance technique used in this study reflects structural changes in a tissue, and provides an estimate of the level of oedema by a simple impedance index. Sodium lauryl sulphate (SLS), dissolved in water at concentrations of 0.1, 0.5 and 2.0%, was applied for 24 h in 12 mm Finn chambers on both volar forearms of 12 healthy volunteers. An unoccluded area was used as a reference site. Readings from all sites were taken before the application of the irritant, and 24 h after its removal. After the last reading, a 3-mm punch biopsy was taken from each test site for histological examination. The results obtained from electrical impedance measurements at five different skin depths were correlated with those obtained from histological examination, visual scoring and transepidermal water loss (TEWL). For all of the methods used the responses were proportional to the concentration of the irritant. Statistically significant changes of electrical impedance were found for all depths and concentrations, except for 0.1% SLS at the most superficial depth. The histological changes were focused in the epidermis, and mainly consisted of oedema. Alterations in the thickness of the epidermis due to oedema were used as a quantitative parameter for correlation with the assessment of irritation using the electrical impedance technique. For the detection of irritant reactions, TEWL and electrical impedance are more sensitive than visual scoring, and selection of the optimum depth penetration further increases the sensitivity of the electrical impedance measurement.

Adult↗

PubMed1992

Are specific reading and writing difficulties causally connected with developmental spatial inability? Evidence from two cases of developmental agnosia and apraxia.

Two cases studies of subjects suffering from severe developmental constructional apraxia are presented. These two subjects demonstrated normal to high ability in reading, writing and arithmetical tests. The analysis of cognitive tests performed by them indicates that extreme developmental, perceptual, spatial and motor deficits may be dissociated from the acquisition of efficient reading ability.

Achievement↗

PubMed2001

Accurate in vivo dosimetry of a randomized trial of prostate cancer irradiation.

PURPOSE: To guarantee an accurate dose delivery, within +/- 2.5%, in a Phase III randomized trial of prostate cancer irradiation (68 vs. 78 Gy) by means of a comprehensive in vivo dosimetry program. METHODS AND MATERIALS: Prostate patients are generally treated in our clinic with a 3-field isocentric technique: an 8-MV anteroposterior beam and 2 18-MV wedged laterals. All fields are shaped conformally to the PTV. Patients were randomized between two dose levels of 68 Gy and 78 Gy. During treatment, the entrance and exit dose were measured for each patient with diodes. Special 2.5-mm thick steel build-up caps were applied to make the diodes appropriate for measurements in 18-MV photon beams as well. Portal images were used to verify the correct position of the diodes and to detect and correct for gas filling in the rectum that may influence the exit dose reading. Entrance and exit dose measurements were converted to midplane dose, which was used in combination with a depth dose correction to obtain the dose at the specification point. An action level of 2.5% was applied. RESULTS: The added build-up for the diodes in the 18-MV beams resulted in correction factors that were only slightly sensitive to changes in beam setup and comparable to the corrections used in the 8-MV beams for diodes without extra build-up. The calibration factor increased almost linearly with cumulative dose: 0.7%/kGy for the 8-MV and 1.2%/kGy for the 18-MV photon beams. The introduction of average correction factors made the analysis easier, while keeping the accuracy within acceptable limits. In a period of 3 years, 225 patients were analyzed, from which 8 patients needed to be corrected. The average ratio of measured and prescribed dose was 1.009 (standard deviation [SD] 0.012) for the total group treated on two linear accelerators. When the results were analyzed per accelerator, the ratios were 1.002 (SD, 0.001) for Accelerator A and 1.015 (SD, 0.001) for Accelerator B. This difference could be attributed to the cumulative effect of three small imperfections in the performance of Accelerator B that were well within the limits of our quality assurance program. CONCLUSION: Diodes can be used for accurate in vivo dosimetry during prostate irradiation in high-energy photon beams. The dose delivery in this randomized trial is guaranteed within the 2.5% limits on an individual patient basis. This could not be achieved without the in vivo dosimetry program, despite our high-standard quality assurance program of treatment delivery.

Algorithms↗

PubMedDate not supplied

[New ultrashort scheme for helicobacter pylori infection eradication using tetracyline, furazolidone and colloidal bismuth subcitrate in dyspeptic patients with or without peptic ulceration in the National Hospital Cayetano Heredia].

BACKGROUND: Helicobacter pylori (Hp) infection has been associated with the presence of duodenal ulcer, gastric ulcer and chronic active gastritis. It is also speculated that Hp may have a major role in gastric cancer development. Due to rising antibiotic resistance, probably lack of compliance and the expense of the currently used antimicrobial regimens, it's important to develop efficacious, short-duration and low cost therapies, especially for the treatment of low-income populations from underdeveloped countries. The goal of the present study is to asses the efficacy of two ultrashort antibiotic schemes against Hp infection. METHODS: Patients with diagnosis of Hp infection, found in antral gastric biopsies, were included. They were randomly assigned to receive one of the following therapeutic schemes: tetracycline 500 mg qid, furazolidone 100 mg qid and colloidal bismuth subcitrate 120 mg qid for 3 days (Scheme I) or 4 days (Scheme II). Patients were instructed to come back for follow-up at least 8 weeks after starting medication. At the control visit, an upper endoscopy was performed and an average of 3 antral biopsies was taken. Biopsies were stained with hematoxylin-eosin for histological assessment and with Warthin-Starry silver staining for Hp diagnosis. A single experienced pathologist read all biopsies. In both, the initial biopsy and the control one, we evaluated: presence of Hp; presence, depth and grade of chronic gastritis; presence and grade of inflammatory activity; presence, grade and extent of mucinous damage; presence of glandular atrophy, intestinal metaplasia and lymphoid follicles. We also evaluated dyspeptic symptoms prior and after the treatment, and the presence of adverse events. RESULTS: 80 patients were enrolled, 2 were excluded because of intense nausea and vomits, 4 patients didn't follow the indications properly and 8 patients couldn't be contacted for the control visit. From the remaining 66 patients, 32 were assigned to Scheme I and 34 to Scheme II, both groups were comparable. Eradication rate was 68.8% (22/32) (CI = 52.1% - 82.7%) for Scheme I and 88.2% (30/34) (CI = 74.9% - 96.2%), significant higher, for Scheme II. There was decrease of dyspeptic symptoms and significant improvement of the histological pattern for both groups, except for presence of chronic gastritis, intestinal metaplasia, glandular atrophy and lymphoid follicles. Hp eradication was associated with significant symptoms decrease, normal endoscopy raising and improvement of all the histological parameters, except for presence of intestinal metaplasia and glandular atrophy. Treatment was well tolerated, 57.6% of the patients reported only mild adverse events, nausea was the most frequent (19.7%) and there was no difference between schemes. CONCLUSIONS: The triple ultrashort duration scheme including tetracycline, furazolidone and bismuth for 4 days is efficacious against Hp, with a high eradication rate (88.2%). The Hp disappearance is followed by improvement in every histological parameter that we evaluated, except for glandular atrophy and intestinal metaplasia; and it's also accompanied by a decrease in dyspeptic symptoms.

Adolescent↗

PubMed1993

[The readers of the Nederlands Tijdschrift voor Geneeskunde].

In order to establish the reach, the reading frequency and the appreciation of the Nederlands Tijdschrift voor Geneeskunde, a telephone inquiry was conducted among a random sample of specialists, general practitioners, registrars and pharmacists in the Netherlands. The response amounted to 81.5% (n = 1515). Of the respondents, 94% received the Journal, and two-thirds read it every week. Eight out of ten saved the Journal, five even all volumes. The reading frequency varied greatly from one section to another. Of those who read the Journal at all, 74% always or often read the clinical lesson and 6% the original articles. Although, due to increasing specialization (in width and in depth), it is becoming increasingly difficult to satisfy all readers, the appreciation of the articles is high.

Humans↗

PubMed2006

Does depth perception require vertical-disparity detectors?

Stereo depth perception depends on the fact that objects project to different positions in the two eyes. Because our eyes are offset horizontally, these retinal disparities are mainly horizontal, and horizontal disparity suffices to give an impression of depth. However, depending on eye position, there may also be small vertical disparities. These are significant because, given both vertical and horizontal disparities, the brain can deduce eye position from purely retinal information and, hence, derive the position of objects in space. However, we show here that, to achieve this, the brain need measure only the magnitude of vertical disparity; for physically possible stimuli, the sign then follows from the stereo geometry. The magnitude of vertical disparity--and hence eye position--can be deduced from the response of purely horizontal-disparity sensors because vertical disparity moves corresponding features off the receptive fields, reducing the effective binocular correlation. As proof, we demonstrate an algorithm that can accurately reconstruct gaze and vergence angles from the population activity of pure horizontal-disparity sensors and show that it is subject to the induced effect. Given that disparities experienced during natural viewing are overwhelmingly horizontal and that eye position measures require only horizontal-disparity sensors, this work raises two questions: Does the brain in fact contain sensors tuned to nonzero vertical disparities, and if so, why?

Algorithms↗

PubMed1987

Proprioceptive knowledge of eye position.

The peripheral and central apparatus for extraretinal (non-visual) sensing of eye position by proprioception (inflow) is documented. The functional significance of this inflowing signal is shown by its role in (1) providing oculomotor stability in fixation and conjugacy, (2) specification of visual direction, (3) development of some visual functions, and (4) depth and vergence responses. Inflow is seen as a slowly-operating calibrator of eye position, with outflow signals read out from the underlying inflow signal. Good "preparations" for studying inflow include humans having their extraocular muscles surgically manipulated in some way for treatment, or those with some deficit in the afferent pathways. A complete understanding of the oculomotor system, in normal and pathological conditions, demands the inclusion of inflow.

Animals↗

PubMed1981

Radial keratotomy in fresh human cadaver eyes.

Radial keratotomy in fresh human cadaver eyes produced corneal flattening varying from 6 to 11 diopters (D). There was no significant difference in the effectiveness of the incisions to the incisions to the limbus compared to incisions through the limbus. Eighty to ninety percent of the flattening effect was obtained after the first eight incisions. The preoperative keratotomy reading was not helpful in predicting the final result. Histopathology of the incised corneas revealed considerable variation in incision depth and demonstrates the difficulty in achieving deep incisions safely.

Aged↗

PubMed2006

Making sense of qualitative data analysis: an introduction with illustrations from DIPEx (personal experiences of health and illness).

OBJECTIVES: This paper outlines an approach to analysing qualitative textual data from interviews and discusses how to ensure analytic procedures are appropriately rigorous. OVERVIEW: Qualitative data analysis should begin at an early stage in data collection and be highly systematic. It is important to identify issues that emerge during the data collection and analysis as well as those that the researcher may have anticipated (from reading or experience). Analysis is very time-consuming, but careful sampling, the collection of rich material and analytic depth mean that a relatively small number of cases can generate insights that apply well beyond the confines of the study. One particular approach to thematic analysis is introduced with examples from the DIPEx (personal experiences of health and illness) project, which collects video- and audio-taped interviews that are freely accessible through http://www.dipex.org. EVALUATION: Qualitative analysis of patients' perspectives of illness can illuminate numerous issues that are important for medical education, some of which are unlikely to arise in the clinical encounter. Qualitative studies can also cover a much broader range of experiences - of both common and rare disease - than clinicians will see in practice. The DIPEx website is based on qualitative analysis of collections of interviews, illustrated with hundreds of video and audio clips, and is an innovative resource for medical education.

Attitude to Health↗

PubMed1997

Regularized progressive expansion algorithm for recovery of scattering media from time-resolved data.

Reconstructions of the absorption cross sections of dense scattering media from time-resolved data are presented. A progressive expansion (PE) algorithm, similar to a layer-stripping, is developed to circumvent the underdeterminedness of the inverse problem. An overlapping scheme, which used detector readings from several consecutive time intervals, is introduced to reduce the propagation of reconstruction errors that occur at shallower depths. To reduce the sensitivity of the PE algorithm to noise a regularized progressive expansion (RPE) algorithm is proposed, which incorporates regularization techniques into the PE algorithm. The PE and the RPE algorithms are applied to the problem of image reconstruction from time-resolved data. The test media were isotropically scattering slabs containing one or two compact absorbers at different depths below the surface. The data were corrupted by additive white Gaussian noise with various strengths. The reconstruction results show that the PE and the RPE algorithms, when they are combined by proper overlapping, can effectively overcome the underdeterminedness of the inverse problem. The RPE algorithm yields reconstructions that are more accurate and more stable under the same noise level.

Algorithms↗

PubMed2006

Depth of focus in eyes with diffractive bifocal and refractive multifocal intraocular lenses.

PURPOSE: To evaluate monocular and binocular depth of focus in eyes with different multifocal intraocular lens (IOLs) systems. SETTING: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. METHODS: In this comparative interventional study, binocular implantation of multifocal IOLs was performed in 3 groups. In the first group, 26 eyes of 13 patients received asymmetric Acri. Twin (Acri.Tec) IOLs, a near-weighted 733D in 1 eye and a distance-weighted 737D in the fellow eye. In the second group, 26 eyes of 13 patients received a diffractive 811E IOL (Pharmacia). In the third group, 26 eyes of 13 patients received a refractive Array IOL (AMO). The visual acuity was tested monocularly and binocularly starting at 6 m in 0.50 diopter (D) defocusing steps. RESULTS: Distance visual acuity was best in eyes with the distance-dominated 737D IOL; eyes with the other IOLs had comparable results. Binocular distance visual acuity was comparable between the Acri. Twin group and the 811E group. The Acri. Twin group had better distance visual acuity than the Array group (P< or =.048). Near visual acuity was best in eyes with the near-weighted 733D, followed by the 737D and the 811E. Patients with Array IOLs had worse visual acuities at reading distance (between 33 cm and 40 cm) (P< or =.001). Patients with diffractive bifocal IOLs had better results than patients with refractive multifocal IOLs at reading distance (P< or =.018). CONCLUSION: The diffractive IOLs performed better than refractive IOLs. Asymmetric-weighted IOLs provided better binocular depth of field.

Aged↗

PubMed2006

Emotional words: what's so different from just words?

Aphasic patients, in particular global aphasics, may still swear and produce emotional utterances with ease. Based on these clinical observations we investigated emotional word "reading" in a series of different experiments over 25 years, not only in aphasic patients, but also in the left (LVF) and right (RVF) visual fields of healthy subjects, and in a depth-recorded epileptic patient. Across these experiments we found: i) behaviorally a strong emotional word effect in the left visual field (right hemisphere - RH) of normals, correlating well with the emotional word performance of aphasic patients, pointing to a specific role of the right hemisphere; ii) electro-physiologically a specific early (100-140 msec) brain response to emotional words during scalp recordings in healthy subjects subsequent to right visual field (left hemisphere - LH) stimulation, that source localization procedures project to posterior areas of the right hemisphere; iii) preliminary data of a very early (60 msec) activation of the left amygdala in a depth-recorded epileptic patient when the same emotional words were presented to the right visual field (left hemisphere); and iv) a consistent gender difference showing that the above findings might be relevant for men only. Both hemispheres therefore appear to be implicated in emotional word "reading" but in different ways. We propose that the left amygdala via extrastriate connections acts as a detector of emotional word content at a very early stage of processing; that this amygdala response subsequently modulates the cortical response to emotional words asymmetrically, rendering the left visual cortex less sensitive to emotional words than that of the right hemisphere; and that this modulation is gender dependent.

Affect↗

PubMed2025

Absolute copy number aware CNV calling of sub-megabase segments in ultra-low coverage single-cell DNA sequencing data.

Recent advances in ultra-low coverage whole-genome sequencing (WGS) of single cells have enabled detailed analysis of copy number variation at a throughput approaching that of single-cell RNA sequencing. However, downstream computational methods have not seen comparable advances and are largely adaptations of deep sequencing methodology with reduced precision. Here, we present ASCENT, a computational method built to take full advantage of modern direct tagmentation-based WGS at ultra-low depth. Using joint segmentation with high-resolution bins, we accurately detect small segments, achieving accurate copy number profiles even at 100 000 reads per cell. ASCENT implements true absolute copy state inference for single cells, based on statistical modeling of coverage rather than comparison to a reference, while taking variable segment copy state into account. Further, ASCENT implements per-segment copy-neutral loss of heterozygosity (LOH) calling without the need for non-tumor or bulk WGS reference. When applied to a pediatric B-ALL sample, ASCENT finds copy-neutral LOH in a small segment and a minor subclone defined by breakpoints missed in bulk WGS. Thus, by applying appropriate computational methods, single-cell WGS provides clear advantages over bulk, even at a relatively low cell number and sequencing depth.

DNA Copy Number Variations↗

PubMed1999

A parallel noise-robust algorithm to recover depth information from radial flow fields.

A parallel algorithm operating on the units ('neurons') of an artificial retina is proposed to recover depth information in a visual scene from radial flow fields induced by ego motion along a given axis. The system consists of up to 600 radii with fewer than 65 radially arranged neurons on each radius. Neurons are connected only to their nearest neighbors, and they are excited as soon as a sufficiently strong gray-level change occurs. The time difference of two subsequently activated neurons is then used by the last-excited neuron to compute the depth information. All algorithmic calculations remain strictly local, and information is exchanged only between adjacent active neurons (except for the final read-out). This, in principle, permits parallel implementation. Furthermore, it is demonstrated that the calculation of the object coordinates requires only a single multiplication with a constant, which is dependent on only the retinal position of the active neuron. The initial restriction to local operations makes the algorithm very noise sensitive. In order to solve this problem, a predication mechanism is introduced. After an object coordinate has been determined, the active neuron computes the time when the next neuronal excitation should take place. This estimated time is transferred to the respective next neuron, which will wait for this excitation only within a certain time window. If the excitation fails to arrive within this window, the previously computed object coordinate is regarded as noisy and discarded. We will show that this predictive mechanism relies also on only a (second) single multiplication with another neuron-dependent constant. Thus, computational complexity remains low, and noisy depth coordinates are efficiently eliminated. Thus, the algorithm is very fast and operates in real time on 128 x 128 images even in a serial implementation on a relatively slow computer. The algorithm is tested on scenes of growing complexity, and a detailed error analysis is provided showing that the depth error remains very low in most cases. A comparison to standard flow-field analysis shows that our algorithm outperforms the older method by far. The analysis of the algorithm also shows that it is generally applicable despite its restrictions, because it is fast and accurate enough such that a complete depth percept can be composed from radial flow field segments. Finally, we suggest how to generalize the algorithm, waiving the restriction of radial flow.

Algorithms↗

PubMed1996

Apparent accommodation and depth of field in pseudophakia.

PURPOSE: To assess depth of field in phakic and pseudophakic eyes to explain good distance and uncorrected near visual acuity in pseudophakic eyes. SETTING: Department of Ophthalmology, University of Otago Medical School, Dunedin, New Zealand. METHODS: Depth of field was measured in pseudophakic (n = 10) and phakic (n = 10) eyes for both near and distant targets. Test conditions included cycloplegia and a constant pupillary aperture using a soft contact lens with a central artificial pupil diameter of 2.5 mm. RESULTS: There was no statistically significant difference between phakic and pseudophakic eyes for any test. Depth of field for near visual acuity was +/-0.85 diopters (D), but amplitude of legibility was +/-1.94 D. Depth of field for distance visual acuity was between 0.25 and 0.50 D in 85% of eyes. CONCLUSION: In the absence of astigmatism and disease, a pseudophakic eye with -0.75 D of myopia can expect to achieve 20/30 uncorrected distance acuity and read N5 unaided if the pupil is approximately 2.5 mm.

Accommodation, Ocular↗