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Biomedical subjects

V Yang

Publications and source records attributed to V Yang.

10 recordsLinked to original sources
PubMed2006

Estimation methods for flow imaging with high frequency ultrasound.

This article proposes to estimate slow blood flow with high frequency ultrasound imaging. The proposed technique combines 2 methods. First, a statistical method, called Speckle Flow Imaging (SFI) based on the analysis of changes in the speckle pattern along time, gives an index directly related to the total velocity vector. Secondly, a block matching approach estimates the in-plane velocity components. Results on calibrated flow sequences of blood mimicking fluid have shown good agreement with the statistical model. The quantification of flow is achieved with pulsed flow and is also angle independent when the flow is perpendicular to the ultrasound beam. Speckle Tracking has been evaluated on the same data and has shown good estimation of the in-plane velocity vector when the component of velocity perpendicular to the imaging plane is inferior to 1mm/s. The results of these two methods permit the evaluation of the total 3D velocity field and the orthogonal velocity component relative to the imaging plane. This allows the quantification of blood flow (volumetric per time unit across the sequence).

Algorithms↗
PubMed2000

Reliability and dimensionality of judgments of visually textured materials.

We extended perceptual studies of the Brodatz set of textured materials. In the experiments, texture perception for different texture sets, viewing distances, or lighting intensities was examined. Subjects compared one pair of textures at a time. The main task was to rapidly rate all of the texture pairs on a number scale for their overall dissimilarities first and then for their dissimilarities according to six specified attributes (e.g., texture contrast). The implied dimensionality of perceptual texture space was usually at least four, rather than three. All six attributes proved to be useful predictors of overall dissimilarity, especially coarseness and regularity. The novel attribute texture lightness, an assessment of mean surface reflectance, was important when viewing conditions were wide-ranging. We were impressed by the general validity of texture judgments across subject, texture set, and comfortable viewing distances or lighting intensities. The attributes are nonorthogonal directions in four-dimensional perceptual space and are probably not narrow linear axes. In a supplementary experiment, we studied a completely different task: identifying textures from a distance. The dimensionality for this more refined task is similar to that for rating judgments, so our findings may have general application.

Adult↗
PubMed1991

Genetic transformation of Aureobasidium pullulans.

Aureobasidium pullulans strain Y117 was transformed to hygromycin resistance using plasmid pDH33, which contains the bacterial hygromycin B phosphotransferase gene (hph) fused to promoter elements of the Aspergillus niger glucoamylase gene (glaA). Southern hybridizations of transformants revealed multiple, integrated copies of the vector. The glaA promoter was not induced by starch in A. pullulans as it is in A. niger; however, the transcriptional start points were the same in both species.

Aspergillus niger↗
PubMed1991

Neuropsychological performance in medicated and unmedicated patients with Tourette's disorder.

OBJECTIVE: To date, there have been no formal investigations of neuropsychological performance in patients with Tourette's disorder who are taking psychotropic medications. The authors conducted this study to provide such information. METHOD: They examined the neuropsychological performance of 96 patients 6-18 years old who met DSM-III-R criteria for Tourette's disorder; 51 of these patients were taking neuroleptic medications and 45 were not. The groups were well matched with regard to age, sex, education, and duration of symptoms. Each group was given a complete neuropsychological test battery as well as instruments rating symptoms of Tourette's disorder, obsessive-compulsive characteristics, and other behavioral disturbances. RESULTS: The patients taking medications did not differ from those not taking medications on any of the neuropsychological, intellectual, or educational measures. In addition, the groups did not differ with regard to level of Tourette's disorder symptoms. CONCLUSIONS: The results of this investigation suggest that patients with Tourette's disorder who do not experience intolerable side effects from neuroleptic medications are able to perform on educational, intellectual, and neuropsychological tests at a level comparable to that of unmedicated patients. These results have positive implications for patients with Tourette's disorder who respond to neuroleptic medications.

Adolescent↗
PubMed1989

Ovarian stimulation with pure follicle-stimulating hormone/human menopausal gonadotropin and improved laparoscopic aspiration needles influence the success of an in vitro fertilization program.

The effect of a combined pure follicle-stimulating hormone/human menopausal gonadotropin (pFSH/hMG) ovarian stimulation regimen and modified, sharpened laparoscopic follicular aspiration needles on the number of oocytes retrieved and the oocyte/follicle ratio in 43 consecutive cycles of in vitro fertilization (IVF) were retrospectively compared with 99 consecutive preceeding cycles stimulated with hMG alone and captured with aspiration needles that had never been sharpened. A modified laparoscopic follicular aspiration needle is described. Purified FSH/hMG ovarian stimulation significantly improved the mean serum estradiol levels, number of preovulatory follicles, and, therefore, the total number of oocytes recovered per cycle. The mean ratios of oocytes recovered per preovulatory follicle documented on ultrasound, and per aspirated follicle, increased significantly using sharpened needles. Both modifications improved the success rate of our IVF program.

Female↗
PubMed1985

Ultrasound guidance for human embryo transfer.

Embryo transfer is facilitated with ultrasound guidance. The 16 ultrasound-guided transfers were rated easier, and there was less catheter distortion, in comparison with 12 transfers guided by "clinical feel." The benefits we ascribe to ultrasound guidance are as follows: (1) transfers can be done with the patient supine in the lithotomy position; (2) the catheter tip is accurately positioned in the fundus of the uterine cavity; (3) the ejection of the transfer bubble into the uterus and its persistence during catheter removal and documented; and (4) the continuance of the bubble is comforting to the patient. Greater experience is needed before the impact of ultrasound-guided transfer can be correlated with the rate of pregnancy continuance.

Adult↗
PubMed1983

Partial trisomy 10q in three unrelated patients.

This communication describes three unrelated patients with growth and psychomotor retardation, multiple congenital anomalies, and dysmorphic features who were found to have trisomies for the different long arm segments of chromosome 10. After reviewing the clinical and cytogenetic data from the literature and our three patients we concluded that: a) There are at least two different clinical syndromes associated with long arm trisomy of chromosome 10 only one of which, the well known 10q trisomy syndrome, is characterized with specific clinical features. The only trisomic segment common in this latter group of patients with similar phenotype, yet with different trisomic segments, is the distal two bands, q25 and q26. Therefore the determinants for the well-delineated 10q trisomy syndrome seems to be located on the distal bands q25 and q26 and this syndrome would preferably be named "distal 10q trisomy syndrome". b) The patients with proximal and/or middle long arm segment trisomies of chromosome 10 are rare and they have yet undefined clinical features.

Child↗
PubMed1982

Terminal deletion of the long arm of chromosome 10 : q26 to qter. Case report and review of literature.

This communication describes the fourth known patient with a terminal long arm deletion of chromosome 10. The karyotype is : 46,XX,del(10)(q26). The clinical findings in the patient included intrauterine growth retardation, microcephaly, truncus arteriosus type 1, respiratory distress and craniofacial dysmorphism. Although review of the limited number of patients with a similar deletion reveals several common features, there is yet insufficient evidence to define a distinct 10q--syndrome.

Abnormalities, Multiple↗
PubMed1976

Incidence of Z band streaming and myofibrillar disruptions in skeletal muscle from healthy young people.

Skeletal muscle tissue was obtained from the vastus lateralis or peroneus brevis muscles of 34 healthy volunteers. Focal and extensive areas of Z band streaming and disruption of myofibrillar architecture without Z band streaming were quantified in Araldite-embedded specimens examined in the phase microscope. Extensive areas of Z band streaming in more than 2.0 percent of fibers was present in only two of the 34 volunteers. Myofibrillar disruptions without Z band streaming was much less common than Z band streaming. The size of extensive areas of Z band streaming or myofibrillar disruptions was quantified by counting the number of adjacent fibrils and contiguous sarcomeres occupied by either type of lesion. These data should be of use in determining if such lesions are present in excessive amounts in suspected pathologic material.

Adolescent↗