Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “new methods”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 289 records · Page 16Linked to original sources
PubMed1996

A new method for transcutaneous coaxial neuroendoscopy.

A new method of direct endoscopy of the subarachnoid space and a major part of the ventricles of the human central nervous system is presented. The technique was developed on more than 100 human bodies with the help of a bronchoscope. Percutaneous entry into the subarachnoidal space is performed from the dorsal side between vertebrae L5 and S1. The endoscope can be moved along the spinal cord on both the dorsal and the ventral side. From the dorsal side of spinal cord the cerebello-medullary cistern can be reached. The fourth ventricle is entered through the median aperture and then the third ventricle through the cerebral aqueduct. From the ventral side of the spinal cord the posterior cranial fossa is reached and the large arteries and the cranial nerves can be inspected. The main conclusion of the present report is that the subarachnoid space seems to be large enough for a coaxial exploration with a 3-5 mm diameter fibroscope if the investigator possesses a good knowledge of the subarachnoid anatomy. The technique provides new approaches in research and possibilities of clinical investigations and therapy.

Cadaver↗
PubMed2005

A new method for generating poroelastograms in noisy environments.

Poroelastography has been recently introduced as a new elastographic technique that may be used to describe the spatial and temporal behavior of poroelastic materials. The experimental methodology proposed thus far for phantoms and tissues in vitro requires the acquisition of a precompression rf frame, the application of a unit step strain compression to the sample and the acquisition of subsequent post-compression frames from the material. Elastograms and poroelastograms are generated by cross-correlating the sequentially-acquired postcompression frames with the reference precompression frame. The application of poroelastography to tissues in vivo must address the echo decorrelation problems that are encountered due to uncontrolled tissue motion, which may become significant shortly after the acquisition of the precompression frame. In this paper, we investigate the feasibility of performing poroelastography experiments using an alternative experimental scheme. In the proposed experimental methodology, the reference precompression frame is continuously moved while the time interval between the frames that are correlated is kept short. This allows long data acquisition times with simultaneous minimization of the decorrelation due to undesired tissue motion in vivo. We validated this new method using both a step and a ramp compression functions. We performed poroelastographic simulations and experiments in phantoms and in tissues in vivo. The results were compared to those obtained using the traditional acquisition methodology. This study shows that the two methods yield similar results in vitro and suggests that the new method may be more robust to decorrelation noise in applications in vivo.

Arm↗
PubMed1995

Section directed cryosectioning of specimens for scanning electron microscopy: a new method to study cardiac development.

A new method to study the developing heart was developed. Using this "section directed" cryosectioning method, appropriate fixed embryos can be trimmed optimally to obtain sectional planes that, if necessary, can be matched with histologically treated sections. As a result, the morphological information obtained with the scanning electron microscope can be compared in detail with the information on the molecular phenotypes of the subpopulations of cells as deducted from staining patterns of the sections. This method allows combination of the specific advantages of sophisticated histological techniques, such as immunohistochemistry and in situ hybridisation, with those of the scanning electron microscope.

Animals↗
PubMed1989

Confocal scanning fluorescence microscopy: a new method for phagocytosis research.

An important new method for phagocytosis research, confocal scanning fluorescence light microscopy (CSFM), is demonstrated using fluorescent microspheres ingested by murine macrophages. CSFM, in combination with Nomarski differential interference contrast microscopy (DIC), can resolve microspheres inside cells from microspheres attached to the surface of cells. Further, combined CSFM and DIC images can quantitate phagocytosis by individual cells aggregated together. No other method offers these capabilities. A comparison of CSFM and conventional epifluorescence light microscopy (EFM) images shows that CSFM produces significantly higher-resolution images of microspheres than EFM, primarily because CSFM excludes the out-of-focus light artifacts of EFM.

Animals↗
PubMed1986

Tibial realignment by oblique wedge osteotomy. A new method based on accurate measurement.

A new method for calculating the angle of correction in upper tibial osteotomies is described. The wedge differs from the current techniques in being oblique. The apex is sited on the medial cortex to lie level with the tibial tubercle. The wedge is coned downwards at an angle of 45 degrees, based laterally. This keeps clear of the bifurcation of the popliteal artery, whilst still being contained in the cancellous zone. The method of accurately determining the angle of the wedge and the width of the base using logarithmic calculations is outlined. Being oblique, on removal of the wedge, the cut surfaces match as they meet. Two screws are inserted to lie at right angles to the plane of osteotomy. A long leg plaster cast is worn for six weeks. Thereafter a cast brace is substituted to permit knee and ankle movements. The osteotomy unites rapidly across the large oblique contact surfaces. Pain relief has been substantial and lasting in every patient. The range of flexion returned to the level elicited under anaesthesia immediately prior to the operation.

Ankle↗
PubMed1975

A new method of in situ hybridization.

A new method for gene mapping at the chromosome level using in situ hybridization and scanning electron microscopy is described and has been applied to mapping the rRNA genes of Drosophila melanogaster. Biotin is covalently attached to Drosophila rRNA via a cytochrome c bridge at a ratio of one cytochrome-biotin per 130 nucleotides by a chemical procedure. Polymethacrylate spheres with a diameter of ca. 60 nm are prepared by emulsion polymerization and are covalently attached to the protein avidin at a ratio of 5-20 avidins per sphere. The biotin-labeled rRNA is hybridized to denatured DNA in a chromosome squash. Upon incubation with a sphere solution, some of the biotin sites become labeled with spheres because of the strong non-covalent interaction between biotin and avidin. The chromosome squash is examined in the scanning electron microscope (SEM). Polymer spheres, which are visible in the SEM, are observed to label the nucleolus, where the rRNA genes are located.

Animals↗
PubMed1988

A new method of sequencing DNA.

An entirely new method of sequencing DNA has been devised that does not use electrophoresis, radioactivity, or fluorescence. The method works by measuring pyrophosphate generated by the DNA polymerization reaction. DNA and DNA polymerase are held by a DEAE-Sepharose column and solutions containing different dNTPs are pumped through. The pyrophosphate generated is measured continuously by a device consisting of a series of columns containing enzymes covalently attached to Sepharose. The alternating copolymer poly(dA.dT) is sequenced as an illustration of the method. Future improvements that will facilitate automation are discussed.

Base Sequence↗
PubMed1985

A new method to measure foot contact.

A new method to measure foot contact is described. It consists of a pressure sensitive transducer attached to one end of a flexible silicone rubber tube. A reliable indicator of foot contact is obtained with the tube glued to the outer perimeter of the sole of a shoe.

Humans↗
PubMed1993

A new method for diffusion weighted imaging.

A new method for generating diffusion contrast in magnetic resonance imaging is presented. This technique is robust enough to allow implementation on conventional imaging systems without hardware modifications. Results from phantom measurements are reported. Qualitative contrast changes in magnetic resonance images derived from live mammalian brain are also demonstrated.

Animals↗
PubMed2005

Hierarchical clustering of the correlation patterns: new method of domain identification in proteins.

New method of identification of dynamical domains in proteins - Hierarchical Clustering of the Correlation Patterns (HCCP) is proposed. HCCP allows to identify the domains using single three-dimensional structure of the studied proteins and does not require any adjustable parameters that can influence the results. The method is based on hierarchical clustering performed on the matrices of correlation patterns, which are obtained by the transformation of ordinary pairwise correlation matrices. This approach allows to extract additional information from the correlation matrices, which increases reliability of domain identification. It is shown that HCCP is insensitive to small variations of the pairwise correlation matrices. Particularly it produces identical results if the data obtained for the same protein crystallized with different spatial positions of domains are used for analysis. HCCP can utilize correlation matrices obtained by any method such as normal mode or essential dynamics analysis, Gaussian network or anisotropic network models, etc. These features make HCCP an attractive method for domain identification in proteins.

Algorithms↗
PubMed2003

A new method for mapping macromolecular topography.

A new method, using circular variance, is introduced for mapping macromolecular topography. Circular variance, generally used to measures angular spread, can be used to characterize of molecular structures based on a simple idea. It will be shown that the circular variance of vectors drawn from some origin to a set of points is well correlated with the degree to which that origin is inside/outside the chosen points. In addition, it has continuous derivatives that are also easy to compute. This concept will be shown to be useful for: (i) distinguishing between atoms near the surface of a macromolecule and those in either the deep interior or remote exterior; (ii) identifying invaginations (even shallow ones); and (iii) detecting linker regions that interconnect two domains.

Algorithms↗
PubMed1987

A new method for representing mental growth.

A new method is described for plotting the growth in mental development from birth to adolescence. Using data from a large sample of twins followed since birth, a dimension of mental growth was constructed by arraying all tests in order of difficulty, then computing the average gain from age to age. The gain was expressed in standard-deviation units, which reflected the upward shift in the score distribution from time X to time X + 1. When cumulated over ages, the scores generated a mental growth curve for the sample as a whole, as well as for each case individually. The curves displayed a very rapid gain in mental growth over the first 24 months of life, with the complexity of mental functions advancing by nearly 20 standard deviations from birth to two years. Thereafter the gain progressively tapered off until reaching a final increment of 0.5 SD gain between 15 years and adulthood. At this point, the terminal level of mental growth reached an average value of 31 SD units, with a spread of individual differences equal to +/- 3 SD units. The scores at each age represented a combination of base level plus gain from the preceding age, and during infancy the gain scores were large in relation to base. At later ages, however, the gain scores were comparatively small, both in absolute terms and in relation to base. These characteristics help explain the typical low-order correlations obtained among mental test scores during infancy, vs the progressively larger correlations obtained at later ages.

Adolescent↗
PubMed1988

Measurement of acceleration: a new method of monitoring neuromuscular function.

A new method for monitoring neuromuscular function based on measurement of acceleration is presented. The rationale behind the method is Newton's second law, stating that the acceleration is directly proportional to the force. For measurement of acceleration, a piezo-electric ceramic wafer was used. When this piezo electrode was fixed to the thumb, an electrical signal proportional to the acceleration was produced whenever the thumb moved in response to nerve stimulation. The electrical signal was registered and analysed in a Myograph 2000 neuromuscular transmission monitor. In 35 patients anaesthetized with halothane, train-of-four ratios measured with the accelerometer (ACT-TOF) were compared with simultaneous mechanical train-of-four ratios (FDT-TOF). Control ACT-TOF ratios were significantly higher than control FDT-TOF ratios: 116 +/- 12 and 98 +/- 4 (mean +/- s.d.), respectively. In five patients not given any relaxant during the anaesthetic procedure (20-60 min), both responses were remarkably constant. In 30 patients given vecuronium, a close linear relationship was found during recovery between ACT-TOF and FDT-TOF ratios. It is concluded that the method fulfils the basic requirements for a simple and reliable clinical monitoring tool.

Acceleration↗
PubMed1979

Hypertension detection and compliance: permanent site hypertensive evaluation--a new method of increasing patient compliance.

A new method--permanent site hypertensive evaluation with patient revisits--is suggested as a unique way to increase patient compliance. This method reduced mild hypertension for 50% and increased normotension. The easy availability of permanent sites may induce the patient to return regularly, or the patient may be testing the medication or his physician. But whatever the means, normotension is the aim of compliance. Thanks to Mark Cohen and his pharmacy staff, Dot, Ruth, Jim, and George for their many long hours of detection work; to my nurse monitor, Pauline Platt; and to my secretary, Gene Koswoski. This study was done in cooperation with the Montgomery County Branch of the Southeastern Pennsylvania Chapter of the American Heart Association, Philadelphia, Pennsylvania.

Blood Pressure↗
PubMed1987

Somatosensory evoked potentials after sequential extremity stimulation: a new method for improved monitoring accuracy.

A new method for improving the accuracy of somatosensory evoked potential (SEP) monitoring is described. Two extremities are stimulated at 5 Hz, with an interextremity stimulus interval of 100 ms. Information from a "control" extremity, such as an arm during scoliosis operation, may allow more rapid and accurate interpretation of changes in SEPs during intraoperative monitoring.

Computers↗
PubMed2004

New method for nonparaxial beam propagation.

A new method for solving the wave equation is presented that is nonparaxial and can be applied to wide-angle beam propagation. It shows very good stability characteristics in the sense that relatively larger step sizes can be taken. An implementation by use of the collocation method is presented in which only simple matrix multiplications are involved and no numerical matrix diagonalization or inversion is needed. The method is hence faster and is also highly accurate.

Journal Article↗
PubMed1977

A new method of cranioplasty. Technical note.

A new method of cranioplasty is described. The skull defect is exposed, and an impression is taken which is used for the construction of a plaster of Paris model of the defect. Methyl methacrylate is molded to the model and thus an accurate reproduction of the skull defect is produced. The technique has the main advantage of good cosmetic appearance and strength.

Humans↗