Search Results - (Author, Cooperation:D. P. Jones)

2013-12-07

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Animals ; *Antigen Presentation ; CD4-Positive T-Lymphocytes/immunology ; CD8-Positive T-Lymphocytes/immunology ; Cell Line ; Cricetinae ; Dendritic Cells/enzymology/*immunology ; Enzyme Activation ; Humans ; Mice ; Mice, Inbred C57BL ; Mice, Mutant Strains ; Microtubule-Associated Proteins/genetics ; Protein-Serine-Threonine Kinases/*biosynthesis/genetics ; Yellow Fever Vaccine/*immunology

2018-06-19

The American Society for Microbiology (ASM)

0099-2240

1098-5336

Biology

2018-03-09

Wiley-Blackwell

0899-8418

1097-0088

Geosciences

Physics

2013-07-26

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

*Climate Change ; *Computer Simulation ; Global Warming ; Ice Cover ; Seasons ; *Temperature

1365-2044

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Summary Pulse oximetry probes placed peripherally may fail to give accurate values of blood oxygen saturation when the peripheral circulation is poor. Because central blood flow may be preferentially preserved, we investigated the oesophagus as an alternative monitoring site. A reflectance blood oxygen saturation probe was developed and evaluated in 49 patients undergoing cardiothoracic surgery. The oesophageal pulse oximeter results were in good agreement with oxygen saturation measurements obtained by a blood gas analyser, a CO-oximeter and a commercial finger pulse oximeter. The median (IQR [range]) difference between the oesophageal oxygen saturation results and those from blood gas analysis were 0.00 (−0.30 to 0.30 [−4.47 to 2.60]), and between the oesophageal oxygen saturation results and those from CO-oximetry were 0.75 (0.30 to 1.20 [−1.80 to 1.80]). Bland–Altman analysis showed that the bias and the limits of agreement between the oesophageal and finger pulse oximeters were −0.3% and −3.3 to 2.7%, respectively. In five (10.2%) patients, the finger pulse oximeter failed for at least 10 min, whereas the oesophageal readings remained reliable. The results suggest that the oesophagus may be used as an alternative monitoring site for pulse oximetry even in patients with compromised peripheral perfusion.

Electronic Resource

1365-2044

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Summary The need for a clinically applicable method of detecting splanchnic hypoxia has led to experimental animal studies which indicated the usefulness of intestinal pulse oximetry. Pulse oximetry relies on detection of photoplethysmographic signals. Before developing a pulse oximeter for the measurement of organ oxygen saturation peri-operatively, we designed a system based on a reflectance photoplethysmographic probe to investigate photoplethysmographic signals from human viscera (bowel, liver, and kidney). Recordings were obtained simultaneously from the abdominal viscera and the finger using identical probes. The probe was held sequentially for up to 2 min on the surface of viscera of 12 patients during routine laparotomy. Measurable splanchnic photoplethysmographic signals were recorded for the first time in humans. There were no statistically significant differences between photoplethysmographic amplitudes from viscera and those from the finger. Our results indicate the feasibility of pulse oximetry for the measurement of visceral oxygenation in humans.

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] Fig. 1 Response of ?-globin (G) and adenovirus-2 major late promoter (Ad) transcription to the K562 nuclear extract. The products of the in vitro transcription reaction were electophoresed in formaldehyde-containing gels. The upper band is the ?-globin transcript, 622 bases long, and the lower is ...

Electronic Resource

1420-9071

Oxygen transfer ; tissue hypoxia ; mitochondria ; respiration, cellular ; diffusion, intracellular ; adaptation to hypoxia

Springer Online Journal Archives 1860-2000

Biology

Medicine

Summary Studies of O2 supply in freshly isolated adult mammalian cells provide new insight into the factors that limit mitochondrial oxygenation in vivo. Of particular importance, mitochondria are present at high densities and often in apparent clusters, both of which contribute to local O2 gradients under hypoxic conditions. Current evidence indicates that the mitochondrial distribution is a component of the differentiated phenotype of adult mammalian cells and that specific motors and anchoring mechanisms are present to allow redistribution in response to developmental, physiological and pathological challenges. To compare the importance of resistance to O2 transfer under different conditions and at different sites along the supply path in vivo, a simple mathematical expression of relative resistance to O2 supply is introduced. Under various pathophysiological conditions, this resistance increases in specific regions of the pulmonary, circulatory of cellular supply path and results in O2 deficiency in the mitochondria. Regardless of cause, the relative resistance increases dramatically in the vicinity of mitochondrial clusters during hypoxia.

Electronic Resource

1438-2199

Amino acids ; Amino acid transport ; Taurine ; MDCK ; LLC-PK

Springer Online Journal Archives 1860-2000

Medicine

Summary Taurine transport was measured in cultured epithelial cells-LLC-PK1 and MDCK-grown on permeable membrane supports. Taurine transport by LLC-PK1 cells was greater on the apical surface compared to the basolateral surface. MDCK cells exhibited greater taurine uptake from the basolateral side. Transepithelial taurine flux was in the direction of apical to basolateral in the LLC-PK1 monolayers. There was no net transepithelial movement of taurine in the MDCK monolayers. Efflux of taurine from the apical and the basolateral membrane surfaces of LLC-PK1 cell monolayers was stimulated by externalβ-alanine but not L-alanine. Efflux of taurine from MDCK cell monolayers was stimulated byβ-alanine on the basolateral surface. While the competitive inhibitor guainidinoeithane sulfonate (GES) competitively inhibited taurine uptake to a similar degree on the apical and basolateral surface of LLC-PK1 cell monolayers, GES had a more potent inhibitory effect on the basolateral taurine uptake in MDCK cells when compared to its inhibition of apical taurine transport. We conclude that there are characteristic differences in transport of taurine by apical and basolateral surfaces of LLC-PK1 and MDCK cells which may be the consequence of asymmetric distribution or unique structural properties of the taurine transporter.

Electronic Resource

1741-0444

Electronic simulator ; Maximal expiration ; M.E.F.V. curve

Springer Online Journal Archives 1860-2000

Biology

Chemistry and Pharmacology

Medicine

Electronic Resource

1741-0444

Forced-expiration measurement ; Pressure-transistor ; Ventilatory capacity ; Venturi-pneumotachography

Springer Online Journal Archives 1860-2000

Biology

Chemistry and Pharmacology

Medicine

Electronic Resource

1741-0444

Tear turnover ; Fluorophotometry ; Ophthalmology

Springer Online Journal Archives 1860-2000

Biology

Chemistry and Pharmacology

Medicine

Abstract An improved continuous reading fluorophotometer with provision for controlling the blink rate has been used to measure tear turnover rates in 14 normal healthy volunteers. A significant difference between morning and afternoon tear turnover results has been found, indicating a possible circadian rhythm in tear flow. Sources of potential systematic error in the measurement method have been identified and analysed. Fluorescence measurements using a thin film cell have confirmed predictions of nonlinearity in fluorophotometer output at high tear film concentrations. The error in tear film fluorescence due to diffusion of fluorescein into the cornea has also been investigated. Simple precautions to minimise these errors are suggested, which should make the measurement method suitable for clinical application.

Electronic Resource

1741-0444

Fluorophotometer ; Ophthalmology ; Tear turnover

Springer Online Journal Archives 1860-2000

Biology

Chemistry and Pharmacology

Medicine

Abstract The use of fluorescein dye for the study of ocular dynamics in ophthalmology is briefly reviewed. General principles for designing objective fluorophotometers for measuring the rate of change of fluorescein concentration are discussed. Details of the circuitry and performance of a new improved objective fluorophotometer using a quartz-halogen excitation source and a synchronous detector are presented. In a preliminary clinical trial the mean tear turnover rate for ten normal subjects was found to be 21±13% min−1.

Electronic Resource

1741-0444

Charge-coupled device ; Infra-red ; Pupillometer

Springer Online Journal Archives 1860-2000

Biology

Chemistry and Pharmacology

Medicine

Abstract A new pupillometer for measuring the size of the pupil of the human eye is described. It uses two inexpensive 256-element charge coupled device (CCD) arrays in an orthogonal configuration. The system is controlled and data are analysed by means of a Z80A microcomputer. Software allows the position and diameter of the pupil to be displayed on a monochrome video monitor. Infra-red diodes irradiate the eye so that measurements can be made in darkness. The accuracy is better than ±0·1 mm, over the range 3·2–9·5 mm. Dynamic measurements of the pupil light reflex response can be made with sampling periods as short as 20 ms.

Electronic Resource

0886-1544

stembody ; microtubules ; phosphorylation ; midbody ; Life and Medical Sciences ; Cell & Developmental Biology

Wiley InterScience Backfile Collection 1832-2000

Biology

Medicine

Phosphorylated proteins have been implicated in the control and regulation of many cellular events. One of the striking features of microtubule organizing centers is that they are rich in phosphoproteins [Vandre et al., 1984]. In this report we describe the application of electron spectroscopic imaging to the study of the spatial and temporal distribution of phosphorus and hence to the study of phosphorylated proteins associated with the formation and organization of one such organizing center, the intercellular bridge. Our study indicates that there are several discrete microtubule-based domains that ultimately come to lie within the intercellular bridge and that there is a unique pattern of phosphorylation-dephosphorylation in some of these domains. These patterns correlate with the concurrent growth and sliding of antiparallel microtubules and the development of interactions among neighboring microtubules.

5 Ill.

Electronic Resource

1573-2673

Springer Online Journal Archives 1860-2000

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Résumé L'influence de la fermeture de la fissure et de l'écoulement élastoplastique sur le comportement à la flexion de tôles minces fissurées, est étudiée en faisant appel à un programme de calcul par éléments finis de la flexion incrémentielle de la tôle en régime élastoplastique. Le programme d'éléments finis a été développé en recourant à des hypothèses satisfaisant la théorie des plaques du quatrième ordre de Kirchhoff; les propriétés mécaniques considérées pour le matériau permettent, par ailleurs, de considérer un écrouissage général isotrope, avec réactions élastiques locales lors du déchargement. Cette technique a été appliquée au problème d'une grande tôle circulaire traversée en son centre par une fissure et soumise à flexion pure en son pourtour. On établit la comparaison de deux cas types du problème de flexion: le premier, où l'on néglige la possibilité d'interférence des faces de la fissure avec le moment de flexion, et le second, où l'on introduit un obstacle cinématique au passage de la fissure au travers du plan de symétrie. Les résultats rapportés isolent les effets de l'écoulement élastoplastique et de la fermeture de la fissure.

Abstract The influence of crack closure and elasto-plastic flow on the bending behavior of thin cracked plates is investigated through use of an incremental elasto-plastic plate bending finite element computer program. The finite element program was developed using assumptions consistent with Kirchhoff fourth order plate theory while the material property treatment permits general isotropic work hardening with local elastic unloading. This technique is applied to the problem of a large centrally through cracked plate subject to remote circular bending. Comparison is drawn between two cases of the bending problem. The first neglects the possibility of crack face interference with bending, and the second includes a kinematic prohibition against the crack face from passing through the symmetry plane. Results are reported which isolate the effects of elasto-plastic flow and crack closure.

Electronic Resource

1573-2673

Springer Online Journal Archives 1860-2000

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Abstract Alternative stress intensity factor solutions are developed for several common fatigue crack propagation specimens. Unlike the K-solutions presently employed, the K-solutions developed herein allow direct integration of the Paris fatigue crack growth rate power law while retaining the same degree of accuracy.

Electronic Resource

1741-0444

Electronic simulator ; Specific airways conductance ; Thoracic gas volume ; Whole-body plethysmography

Springer Online Journal Archives 1860-2000

Biology

Chemistry and Pharmacology

Medicine

Electronic Resource

1741-0444

Electronci circuit ; Flow-volume loops ; Respiration

Springer Online Journal Archives 1860-2000

Biology

Chemistry and Pharmacology

Medicine

Electronic Resource