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At least 235 records · Page 13Linked to original sources
PubMed2005

[Commentary on PU Xiang-cheng's experimental verses of acupuncture and moxibustion].

Pu Xiang-cheng, a famous TCM physician in Sichuan Province, were engaged in medicine for dozens of years, with complete and systematical theory and great academic attainments. He summarized whole course of acupuncture and moxibustion treatment by means of verses with easy to be understood and easy to be read aloud, from examination of acupoints, location of acupoints, needling depth, manipulation, reinforcing and reducing to treatment of diseases in departments of internal medicine, surgery, gynecology and five sense organs, etc., and treatment of fainting during acupuncture. This is valuable medical book in recent time and clinically, it has profound inductive significance for later generations.

Acupuncture↗
PubMed1988

Corneal rupture following radial keratotomy in cats subjected to BB gun injury.

We performed this investigation to determine if radial keratotomy (RK) predisposes an eye to rupture when exposed to projectile trauma. Radial keratotomy was performed on 22 cat eyes; 17 eyes were used as controls. Incision depth was set at 90% by averaging ten corneal thickness readings by ultrasonic pachymetry of each cornea. An optical zone of 4.0 mm was used and eight incisions were made. Eight weeks after RK the cats were divided into three groups, subjected respectively to BB velocities of 148.5 ft/sec (N = 4), 190 ft/sec (N = 5), and 240 ft/sec (N = 13). In groups 1 and 2, all nine eyes had hyphemas and no eyes perforated. In group 3, four of 13 RK eyes had corneal rupture. All control eyes had hyphemas and none ruptured. The study suggests that RK can predispose to rupture eyes exposed to projectile trauma sufficient to produce hyphema.

Animals↗
PubMed1979

Indirect immunoperoxidase tests in the diagnosis of schistosomiasis.

An enzymatic technique, immunoperoxidase histochemistry, was applied in the diagnosis of human schistosomiasis. Sera of patients with S. haematobium, S. mansoni and mixed infection, together with control sera, were studied. The test proved easily applicable and gave reliable results particularly with S. mansoni and double infection. The depth of the colour reaction, was then compared with ELISA readings, but there was no relation in the results of the individual cases.

Enzyme-Linked Immunosorbent Assay↗
PubMed2000

Alterations in the functional anatomy of reading induced by rehabilitation of an alexic patient.

OBJECTIVE: The goal of the study was to measure regional cerebral blood flow (CBF) in a stroke patient with acquired phonologic alexia before and after therapy using the Auditory Discrimination in Depth (ADD) program. BACKGROUND: After rehabilitation of acquired language disorders, functional imaging can detect activity in brain structures that do not mediate language during normal conditions. However, the anatomic correlates of recovery or rehabilitation from acquired reading disorders are largely undescribed. METHODS: Cerebral SPECT scans were obtained before and after the intervention with Auditory Discrimination in Depth. The first and last activation tasks necessitated that the patient read nonwords during radionuclide uptake. Another (control) scan was acquired during performance of a nonlinguistic task shortly before the end of the ADD program. RESULTS: Before therapy, the right hemisphere was inactive during nonword reading relative to the nonlinguistic task. After treatment, nonword reading increased cerebral blood flow in the posterior right perisylvian cortices homologous to the dominant hemisphere areas engaged by reading. Brain activity also increased in Broca's area of both hemispheres. CONCLUSIONS: Dyslexia rehabilitation may facilitate right-hemisphere cortical networks in the reading process and increase engagement of phonologic articulatory motor representations in Broca's area.

Dyslexia↗
PubMed1987

The effect on fixation disparity and associated heterophoria of reading at an abnormally close distance.

It is well established that prism stress on binocular vision produces fixation disparity. It is therefore suggested that fixation disparity is a sign of stress on binocular vision. The authors have previously looked at the stress caused by reading in reduced levels of illumination, and found that the average fixation disparity and associated heterophoria become more exophoric. In this paper the effect on fixation disparity and associated heterophoria of reading at an abnormally close distance is reported. It was found that in 50 young adults fixation disparity and associated heterophoria increased to a greater degree of exo-disparity. An analysis of the visual symptoms indicated that there was also an increase in the visual discomfort and other symptoms.

Adult↗
PubMed2003

Alexia and related reading disorders.

Peripheral dyslexias are the result of impairment to processes that convert letters on the page into an abstract orthographic representation. Many aspects of these disorders are difficult to understand in depth. Invariably, there is evidence that some type of word-level perception occurs rapidly in many patients with LBL reading or neglect dyslexia, yet apparently contradictory evidence indicates that part of the word has been misperceived or that the letters must be analyzed laboriously for conscious identification to occur. Current theories attempt to synthesize these different aspects of the patients' performance, but their development is at an early stage. Questions remain also about the domain specificity of the perceptual impairment in LBL reading and about the nature of spatial attention and spatial frames in neglect dyslexia and other forms of attentional disorder. Current understanding of central dyslexias has perhaps advanced further. Well-developed computational models exist of these dyslexias, as do plausible experimental techniques for revealing the activity of semantic and non-semantic routes in normal readers. Nevertheless, the difficult issue of domain specificity arises again with respect to some of the mechanisms invoked, and in this regard, central and peripheral dyslexias continue to pose the same challenge.

Attention↗
PubMed2005

All Pulfrich-like illusions can be explained without joint encoding of motion and disparity.

In the Pulfrich effect, an interocular time delay results in the perception of depth. Two modified versions, the stroboscopic Pulfrich effect and dynamic visual noise with a delay, are generally explained by postulating an early stage of space/time-inseparable filtering, encoding motion and disparity jointly. However, most disparity sensors in monkey V1 do not show joint motion/disparity encoding, and we recently showed that depth perception in the stroboscopic Pulfrich effect is equally compatible with space/time-separable filtering. Here, we demonstrate that this filtering can be implemented with a population of physiologically plausible energy model units. Similar results are obtained whether the neurons are pure disparity sensors (like most V1 neurons) or joint motion/disparity sensors (like MT). We also demonstrate that the dynamic noise stimulus produces correlations between the activity in pure disparity sensors, and in a separate population of pure motion sensors. These correlations are sufficient to explain the percept. Thus, joint encoding of motion and disparity is not required to explain depth perception in Pulfrich-like stimuli: a brain which encoded motion and disparity in entirely separate neuronal pathways could still experience all of these illusions.

Animals↗
PubMed1998

Neuronal activity of human caudate nucleus and prefrontal cortex in cognitive tasks.

Lesions of the caudate nucleus and prefrontal cortex may display similar cognitive deficits. Recent advances in cognitive neuroscience have clarified the functional role of prefrontal cortical areas in certain cognitive operations involved in simple language tasks. We have addressed the role of the caudate nucleus in tasks of lexical decision, semantic categorization, recognition memory, reading aloud and object naming by recording neuronal activity in patients with depth electrodes. During visual processing of words, caudate cells exhibited excitatory responses related to both semantic and phonological-articulatory encoding with non-overlapping time courses. The firing rate of the cells was increased when the semantic processing was required. This occurred within 400-600 ms after the stimulus onset, or within the first 200-300 ms of the delay period. The increased firing within 1000-1200 ms after the stimulus onset was related to the phonological processing. These responses turned out to be strikingly similar to those in Broca's area. Both reading aloud and explicit memory retrieval tasks elicited a sustained inhibition of firing of the same cells with a greater onset latency. Chronometric comparison of prefrontal, temporo-parietal and caudate activities in similar tasks relates the time course of these activations to the fronto-caudate anatomical loops and helps further understanding of the anatomy and circuitry involved in human cognition.

Attention↗
PubMed1975

Evaluation of the status of binocularity in the non-strabismic and strabismic with regular and prolonged testing.

The need for "in-depth" study of the status of binocularity in true space of both the non-strabismic and strabismic before orthoptics is discussed. Vectogram tests to ascertain the status of binocularity of the non-strabismic and the strabismic are explained. With the strabismic, the Single Oblique Mirror Stereoscope is used and the tests with it are enumerated. Significant enhancement of diagnosis of the status of binocularity in the non-strabismic is obtained by testing over a prolonged period of time, instead of relying only upon tests based upon instantaneous response. Prolonged testing techniques utilizing Vectograms in which the patient used alternating saccadic, jump, oculo-rotary fusional movements from the straight ahead position into the lower reading field are used.

Asthenopia↗
PubMedDate not supplied

Evaluation of the effectiveness of laser fluorescence in monitoring in vitro remineralization of incipient caries lesions in primary teeth.

The purpose of this investigation was to examine the effectiveness of laser fluorescence for monitoring in vitro remineralization of caries lesions. Seventeen natural enamel lesions in primary molars were each cut into two parts. One part was exposed, at room temperature, to a remineralizing solution (experimental) and the other part to water (control) for 28 days. Laser fluorescence readings were taken at the beginning of the experiment and during the experiment. At the end of the experiment, lesion depth in the experimental halves was significantly less than in the control halves (p < 0.01), suggesting that remineralization had occurred. However, the laser fluorescence readings showed no statistically significant changes during the experiment, either in the experimental or control halves. We conclude that laser fluorescence was not able to detect in vitro remineralization of natural incipient caries lesions of primary teeth.

Analysis of Variance↗
PubMedDate not supplied

Differential effects of orthographic transparency on dyslexia: word reading difficulty for common English words.

Orthographic transparency is increasingly being recognised as an important factor in determining the manifestation of dyslexic tendencies in individuals. Recent evidence has shown that normal English-speaking children have reading deficits in the range associated with same age dyslexic German-speaking children for less frequently used words, and English orthography has been identified as a contributing factor. Spencer (Reading (1999) 33(2), 72-77; Journal of Research in Reading (1999) 22(3), 283-292) has proposed a predictive model for English children's reading and spelling deficits, based on orthographic features. Two main factors have been identified: consistency of sound representation and inclusion of redundant letters in English words. Using new data for reading, a unified model will be discussed which incorporates measures of depth of orthographic transparency and relates these to recent positron emission tomography (PET) research. Implications for the relative frequency and severity of dyslexia in both deep and shallow orthographies is considered in the light of such studies.

Brain↗
PubMedDate not supplied

High resolution DSA: experimental and clinical evaluation.

The DSA system has been upgraded for capabilities of slow scan video technique and progressive T.V. read-out of 1024 X 1024 matrix with 10 bits of depth. A square wave test pattern made of lead bar demonstrated moderate improvement in spatial resolution, but imaging of a Burger-Rose phantom revealed no significant increase in contrast resolution. Clinical study of various angiograms with intraarterial injections showed that there was slight improvement in the visibility of the vessels, especially small arterial branches, while there was no increase in visibility of the veins. There were no cases in which diagnoses were altered by application of high resolution DSA. With future improvements of the image intensifiers, DSA with 1024 X 1024 matrix may reveal its potential advantage, especially when coupled to larger image intensifiers such as 12 or 14 in.

Angiography↗
PubMed2000

Dosimetry characterization of 32P catheter-based vascular brachytherapy source wire.

Dosimetry measurements and Monte Carlo simulations for a catheter-based 32P endovascular brachytherapy source wire are described. The measured dose rates were obtained using both radiochromic dye film and an automated plastic scintillator. The investigated source has dimensions of 27 mm in length and 0.24 mm in diameter, and is encapsulated in NiTi. For the radiochromic film measurements, calibrated radiochromic dye film was irradiated at distances between 1 and 5 mm from the source axis in A-150 plastic, and read out with a high-resolution scanning densitometer. The depth-dose curve measured in A-150 is then converted to that in water using correction factors obtained from Monte Carlo calculations. For the scintillator system, direct measurements in water were acquired at distances between 1 and 6 mm from the center of the source, along the perpendicular bisector of the source axis. The scintillator was calibrated in terms of absorbed-dose rate in a reference beta-particle field at multiple depths. The measured dose rates obtained from the film and scintillator measurements were then normalized to the measured source activity, i.e., to convert the measured data to units of cGy/s/mCi. Theoretical dosimetry calculations of the catheter-based 32P wire geometry were also obtained from Monte Carlo simulations using the Electron Gamma Shower code (EGS4), the Monte Carlo N-particle transport code (MCNP4B), and CYLTRAN from the Integrated Tiger Series codes (ITS v.3) and found to be in good agreement. The results of both measurements and calculations are expressed as absorbed-dose rate in water per unit of contained activity (cGy/s/mCi). Comparisons indicate that the measured and calculated dosimetry are in good agreement (<10%) within the relevant treatment distances (1-5 mm). This work fully characterizes the radiation field around a novel 32P beta brachytherapy source in water. The depth-dose curve can be used to calculate the dose to the vessel wall from a 27 mm 32P source wire centered within the vessel lumen.

Algorithms↗
PubMed2004

Thermal and temporal response of ionization chambers in radiation dosimetry.

The temporal and thermal response of various commonly used ion chambers (NEL, Exradin, PTW) with different wall and electrode materials is studied in a water phantom. Measurements were taken in heating water bath having an automatic temperature control mechanism. All chambers were submersed at 3 cm depth in water phantom and connected to separate electrometers for simultaneous readings for a given dose from a 6 MV beam. The temporal response was studied at approximately +/- 10 degrees C from room temperature, i.e., 10 degrees C and 30 degrees C. Temporal results show that all chambers reach quick equilibrium response within < 2 minutes of submersion in water. The steady-state thermal response was dependent upon the water temperature and wall and electrode compositions. The temperature and pressure corrected response of the NEL chamber was least affected by the changes in water temperature, where as the Exradin chamber has positive and PTW has negative slope with water temperature. The response varied within +/-1.5% between 10 degrees C-50 degrees C temperature and is mainly dependent on volume changes rather than the humidity. A correction factor based on thermal coefficients is derived for each chamber. It is concluded that ion chamber correction factors can be divided into first order; temperature and pressure connection, second order; volume correction for thermal expansion, and third order; humidity correction. To eliminate dosimetric error, the temporal and thermal response should be known for a chamber or water phantom temperature should be maintained close to room temperature.

Calibration↗
PubMed2024

A comparison of software for analysis of rare and common short tandem repeat (STR) variation using human genome sequences from clinical and population-based samples.

Short tandem repeat (STR) variation is an often overlooked source of variation between genomes. STRs comprise about 3% of the human genome and are highly polymorphic. Some cause Mendelian disease, and others affect gene expression. Their contribution to common disease is not well-understood, but recent software tools designed to genotype STRs using short read sequencing data will help address this. Here, we compare software that genotypes common STRs and rarer STR expansions genome-wide, with the aim of applying them to population-scale genomes. By using the Genome-In-A-Bottle (GIAB) consortium and 1000 Genomes Project short-read sequencing data, we compare performance in terms of sequence length, depth, computing resources needed, genotyping accuracy and number of STRs genotyped. To ensure broad applicability of our findings, we also measure genotyping performance against a set of genomes from clinical samples with known STR expansions, and a set of STRs commonly used for forensic identification. We find that HipSTR, ExpansionHunter and GangSTR perform well in genotyping common STRs, including the CODIS 13 core STRs used for forensic analysis. GangSTR and ExpansionHunter outperform HipSTR for genotyping call rate and memory usage. ExpansionHunter denovo (EHdn), STRling and GangSTR outperformed STRetch for detecting expanded STRs, and EHdn and STRling used considerably less processor time compared to GangSTR. Analysis on shared genomic sequence data provided by the GIAB consortium allows future performance comparisons of new software approaches on a common set of data, facilitating comparisons and allowing researchers to choose the best software that fulfils their needs.

Humans↗
PubMed1994

A user's guide for avoiding errors in absorbance image cytometry: a review with original experimental observations.

The sources of errors which may occur when cytophotometric analysis is performed with video microscopy using a charged-coupled device (CCD) camera and image analysis are reviewed. The importance of these errors in practice has been tested, and ways of minimizing or avoiding them are described. Many of these sources of error are known from scanning and integrating cytophotometry; they include the use of white instead of monochromatic light, the distribution error, glare, diffraction, shading distortion, and inadequate depth of field. Sources of errors specifically linked with video microscopy or image analysis are highlighted as well; these errors include blooming, limited dynamic range of grey levels, non-linear responses of the camera, contrast transfer, photon noise, dark current, read-out noise, fixed scene noise and spatial calibration. Glare, contrast transfer, fixed scene noise, depth of field and spatial calibration seem to be the most serious sources of errors when measurements are not carried out correctly. We include a table summarizing all the errors discussed in this review and procedures for avoiding them. It can be concluded that if accurate calibration steps are performed and proper guidelines followed, image cytometry can be applied safely for quantifying amounts of chromophore per cell or per unit volume of tissue in sections, even when relatively simple and inexpensive instrumentation is being used.

Cytological Techniques↗
PubMed2003

Comparison of computed radiography and film/screen combination using a contrast-detail phantom.

The purpose of this work is to compare computed radiography (Kodak CR 400) and film/screen combination (Speed 400) systems in regards of patient dose, technique settings, and contrast-detail detectability. A special contrast-detail phantom with drilled holes of varying diameter (detail) and varying depth (contrast) was utilized. Various thicknesses of the Lucite sheets were utilized to simulate scattering tissues. Images of the phantom were acquired using a range of 60-120 kVp for film/screen and CR with a conventional x-ray tube and then for CR with additional 2 mm aluminum added filtration to the x-ray beam. The patient entrance skin dose was measured while maintaining 1.6 o.d. for film/screen images and 1900 Exposure Index for CR images. CR phantom images were displayed on the diagnostic workstation for soft copy reading as well as printed on films for hard copy reading on viewbox. Four physicists evaluated the images by scoring the threshold target depth along the row of the same target diameter. Detection ratio was calculated by counting the number of detectable targets divided by the total number of targets in the phantom. The overall score was related to the patient entrance skin dose, kVp, and the thickness of the scattering material. The patient entrance skin dose was reduced as the additional aluminum filter was added to the x-ray beam. Our findings suggested using a higher kVp setting and additional added filtration would reduce the patient entrance skin dose without compromising the contrast-detail detectability, which was compensated by the contrast manipulation on soft-copy display workstations.

Phantoms, Imaging↗