Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of Tension

  • active tension
  • arterial oxygen tension
  • carbon dioxide tension
  • dialectical tension
  • different oxygen tension
  • dioxide tension
  • dynamic tension
  • ethnic tension
  • ideological tension
  • inherent tension
  • interfacial tension
  • isometric tension
  • line tension
  • low oxygen tension
  • low surface tension
  • membrane tension
  • muscle tension
  • o2 tension
  • oxygen tension
  • physiological oxygen tension
  • political tension
  • resting tension
  • social tension
  • surface tension
  • tetanic tension
  • tissue oxygen tension
  • twitch tension
  • uniaxial tension
  • wall tension

  • Terms modified by Tension

  • tension development
  • tension difference
  • tension force
  • tension glaucoma
  • tension inherent
  • tension measurement
  • tension recording
  • tension specimen
  • tension test
  • tension wood

  • Selected Abstracts

    Managing for Innovation: The Two Faces of Tension in Creative Climates

    Scott G. Isaksen
    Part of managing for innovation is creating the appropriate climate so that people can share and build upon each other's ideas and suggestions. Yet, there are increasing pressures and potential unproductive levels of tension within organizations. This article points out the distinction between two forms of tension that appear within the research on organizational climates for creativity as well as the conflict management literature. The Debate dimension is described as reflecting a more productive idea tension and the Conflict dimension suggests a more non-productive personal tension. A series of studies, across multiple levels of analysis, are summarized and a new study is reported in order to highlight the finding that relatively higher levels of Debate, and lower levels of Conflict are more conducive to organizational creativity and innovation. A practical model for the constructive use of differences is shared, along with a few strategies for reducing the negative tension associated with Conflict and increasing the positive aspects associated with Debate. [source]

    Managing the Efficiency-Flexibility Tension in Innovation: Strategic and Organizational Aspects

    Mats Magnusson
    First page of article [source]

    Double Butterfly Suture for High Tension: A Broadly Anchored, Horizontal, Buried Interrupted Suture

    Helmut Breuninger MD
    Background. The excision of skin lesions such as tumors, nevi, and scars frequently results in tension on surgical wound margins. This tension is commonly counteracted surgically with buried, intracutaneous, interrupted sutures of absorbable material which are anchored vertically in the corium. Method. The horizontal, buried, intracutaneous butterfly suture has been described elsewhere. It is firmly anchored in the corium, everts wound margins, and adapts them nearly as broadly as two vertical sutures. It can also be laid as a double butterfly suture, as described here, and then has the shape of an "8." This double butterfly suture is equivalent to three vertical sutures because of its broad base in the corium. Moreover, it can cope with much greater tension because of its "pulley" effect. A single double butterfly suture usually suffices for small defects, particularly when the wound edges are cut obliquely with a longer rim of epidermis. Materials. We have laid the traditional butterfly suture in more than 35,000 skin lesion excisions since 1985 and the double butterfly suture alone or as a supplement in more than 10,000 sutures since 1992. We use 2-0 to 6-0 polydioxanone for these procedures, since it has proven in trials to be the best-absorbed suture material. Results. In most cases, the resulting scars were narrow and smooth in spite of high tension. Results were unsatisfactory in only 6.2% of procedures. Conclusion. The double butterfly suture described here has the advantages of withstanding tension better while everting wound margins and requiring fewer stitches for wound closure. However, it is important that the suture knot be deeply anchored beneath the corium. [source]

    Diversity Tension and Other Underlying Factors in Discrimination Suits

    R. Roosevelt Thomas Jr.

    Surface Tension and Viscosity of the Ni-based Superalloy CMSX-4 Measured by the Oscillating Drop Method in Parabolic Flight Experiments,

    K. Higuchi
    The surface tension and the viscosity of the Ni-based superalloy CMSX-4 were measured by the oscillating drop method on electromagnetically levitated specimen under reduced gravity conditions on a parabolic flight. The twenty seconds of reduced gravity available in a single parabola proved sufficient for melting, heating into the stable liquid and free cooling to solidification. [source]

    Probabilistic high cycle fatigue behaviour of nodular cast iron containing casting defects

    A. NASR
    ABSTRACT Theoretical and experimental investigations were combined to characterize the influence of surface casting defects (shrinkages) on the high cycle fatigue (HCF) reliability. On fracture surfaces of fatigue samples, the defect is located at the surface. The shape used for the calculation is a spherical void with variable radius. Finite-element simulations were then performed to determine stress distribution around defects for different sizes and different loadings. Correlated expressions of the maximum hydrostatic stress and the amplitude of the shear stress were obtained by using the response surface technique. The loading representative point in the HCF criterion was then transformed into a scattering surface, which has been obtained by a random sampling of the defect sizes. The HCF reliability has been computed by using the Monte Carlo simulation method. Tension and torsion fatigue tests were conducted on nodular cast iron with quantification of defect size on the fracture surface. The S,N curves show a large fatigue life scattering; shrinkages are at the origin of the fatal crack leading to the final failure. The comparison of the computed HCF reliability to the experimental results shows a good agreement. The capability of the proposed model to take into account the influence of the range of the defect sizes and the type of its statistical distribution has been demonstrated. It is shown that the stress distribution at the fatigue limit is log-normal, which can be explained by the log-normal defect distribution in the nodular cast iron tested. [source]

    Bioinspired Structural Material Exhibiting Post-Yield Lateral Expansion and Volumetric Energy Dissipation During Tension

    Lifeng Wang
    Abstract Nature has inspired the design of improved synthetic materials that achieve superior and more efficient mechanical performance. Here microstructures inspired by the inner nacreous layer of seashells are designed and their mechanical properties including stiffness, strength, and energy dissipation are computed using micromechanical analysis. The hierarchical mineral/polymer microstructure can be tailored to achieve not only stiffness and strength, but also lateral plastic expansion during tension providing a volumetric energy dissipation mechanism. [source]

    Once More With Feeling: Ethnographic Reflections on the Mediation of Tension in a Small Team of Call Centre Workers

    Matthew J. BrannanArticle first published online: 12 AUG 200
    This article explores the labour process of a team of call-centre workers based in a multi-client call centre in the West Midlands. Founded on the basis of a 13-month ethnographic study into workplace resistance in call-centre environments, this article provides insights into control in call centres, focusing on sexuality, internal team dynamics and discipline. It is argued that control is exerted through management and information technology but it is crucially exerted laterally in the team and sexuality is an important medium of such control. This article focuses specifically on how worker sexuality is deployed to regulate the tension between contradictory imperatives faced by workers. The article then considers the emotional content of the call-centre labour process, arguing that the apparent resolution of potentially contradictory logic, in fact, depends upon the development by call-centre workers, encouraged by more senior employees, of informal, pseudo-sexualized client relations at the point of production. Crucially however the fieldwork reveals that the demands placed upon customer service representatives are subtly gendered. [source]

    Tuning Nanotubes: Beam to String Transition of Vibrating Carbon Nanotubes Under Axial Tension (Adv. Funct.

    On page 1753, the vibration properties of carbon nanotubes (CNTs) under axial tension are quantificationally studied by X. L. Wei et al. through a novel in situ method for precise and simultaneous measurement of the resonance frequency, the axial tension applied to individual CNTs, and the tube geometry. A gradual beam-to-string transition from multiwalled CNTs to singlewalled CNTs is observed; the CNTs can be tuned like a zither! [source]

    Beam to String Transition of Vibrating Carbon Nanotubes Under Axial Tension

    Xianlong Wei
    Abstract State-of-the-art nanoelectromechanical systems have been demonstrated in recent years using carbon nanotube (CNT) based devices, where the vibration of CNTs is tuned by tension induced through external electrical fields. However, the vibration properties of CNTs under axial tension have not been quantitatively determined in experiments. Here, a novel in situ method for precise and simultaneous measurement of the resonance frequency, the axial tension applied to individual CNTs and the tube geometry is demonstrated. A gradual beam-to-string transition from multi-walled CNTs to single-walled CNTs is observed with the crossover from bending rigidity dominant regime to extensional rigidity dominant regime occur much larger than that expected by previous theoretical work. Both the tube resonance frequency under tension and transition of vibration behavior from beam to string are surprisingly well fitted by the continuum beam theory. In the limit of a string, the vibration of a CNT is independent of its own stiffness, and a force sensitivity as large as 0.25,MHz (pN),1 is demonstrated using a 2.2,nm diameter single-walled CNT. These results will allow for the designs of CNT resonators with tailored properties. [source]

    Aesthetics of Celebration, Tension and Memory: Nigeria Urban Art History

    Adérónké Adésolá Adésŕnyŕ
    This essay, among other things, addresses the question of origin of Nigerian Urban art, a genre basically found in urban spaces. It highlights the various nomenclatures by which the genre has been tagged to date and provides a robust debate on the pioneer and later urban artists in the country noting the characteristics and nuances of their art. Besides establishing the character of Nigerian urban art as compelling and significant to understanding the aesthetic sensibilities and nuances of the producer culture, issues of identity, training, authorship, patronage, social memory and social responsibility, morality and immorality and how they inform, shape and complicate the creative endeavors of urban artists are brought to the fore. In this insightful interrogation of history, people and spaces one finds the emergence of a new artistic order in which Nigerian urban artists establish and expand their own idioms, unite politics with art, engage their own audiences, cultivate their own clientele, tell their own stories and that of the society, create and endorse new identities, and increasingly expand their socioeconomic space. Their creative formats essentially transform into markets where people, products and services unite. They also serve as cultural lenses through which one gain insights into class struggle in a postcolonial society and how a critical mass of the Nigerian public interprets leadership, commerce, and culture. [source]

    The purse-string suture revisited: a useful technique for the closure of cutaneous surgical wounds

    Philip R. Cohen MD
    The purse-string suture provides complete or partial closure of round postoperative skin defects. It is a rapid and simple procedure to perform. Tension placed on the suture uniformly advances the skin from the entire periphery of the wound, resulting in a significant reduction of the defect size and enhancement of hemostasis at the wound edge. The history, modifications of the technique, advantages, and potential complications of the purse-string suture are reviewed. It is not only useful following the removal of nonmelanoma skin cancer but also after the local excision of melanoma. In addition, this technique is especially suitable for the repair of round surgical wounds for patients who are unable to modify their active lifestyles during the week following surgery, individuals concurrently being treated with anticoagulants, antiplatelet agents or both, and people with extensive postoperative defects that would otherwise require either a skin graft or a large cutaneous flap. Typically, the site of the surgical wound following partial or complete closure with the purse-string suture demonstrates excellent long-term cosmetic and functional results. [source]

    Mathematics and Common Sense: A Case of Creative Tension by Philip J. Davis

    Jorma Kaarlo Merikoski
    No abstract is available for this article. [source]

    Dispositional and Situational Moderators of the Relationship Between Leader,Member Exchange and Work Tension

    Robyn Brouer
    This paper examines the relationship between leader,member exchange (LMX) and experienced work tension. The dispositional moderators of positive affectivity (PA) and negative affectivity (NA) and the situational moderator of frequency of interaction with the supervisor are included. We tested these relationships in a sample of 537 employees from various organizations. Specifically, we found that high NA coupled with high LMX produced the highest levels of work tension. Additionally, low frequency of interaction with the supervisor coupled with high LMX produced the highest levels of work tension. Finally, we found that the lowest levels of work tension were reported when individuals had high PA, high LMX, and high frequency of interaction with their supervisors. [source]

    Oxygen Tension Regulates the Expression of ANK (Progressive Ankylosis) in an HIF-1-Dependent Manner in Growth Plate Chondrocytes,,

    Raihana Zaka
    Abstract The proximal promoter region of ANK, a gene that codes for a protein that regulates the transport of inorganic pyrophosphate, contains two hypoxia responsive elements (HREs); therefore, we studied the expression and function of ANK at different oxygen tensions. ATDC5 and N1511 clonal chondrocytic cells were cultured in either hypoxia (2% O2) or normoxia (21% O2). Transcript and protein levels of ANK were depressed in hypoxic conditions, as were levels of extracellular pyrophosphate (ePPi). To determine whether HIF-1 was involved in the oxemic response, Hif-1, knockdown cells were exposed to varying oxygen conditions and ANK expression was assessed. Knockdown of Hif-1, resulted in low levels of expression of ANK in hypoxia and normoxia. Chromatin immunoprecipitation (ChIP) assays explored the binding of Hif-1, to ANK HREs and showed that Hif-1, is able to bind to the HREs of ANK more avidly in normoxia than in hypoxia. Furthermore, functional studies of Hif-1, activity using luciferase reporter assays of wildtype and mutagenized HREs showed that only HRE-1 binds Hif-1, in normoxia. Expression of ANK in growth plate and articular cartilage was low in hypoxic regions of the tissues, and higher levels of ANK expression were observed in the synovium and meniscus in regions that have a normally higher oxygen tension. The data suggest that ANK expression and function in vitro and in vivo are repressed in hypoxic environments and that the effect is regulated by HIF-1. [source]

    Managing Discursive Tension: the Co,Existence of Individualist and Collaborative Discourses in Flight Centre

    Ian Palmer
    Our study of the travel agency Flight Centre began as a case study of a company that appears to be a ,success story' in what is a highly competitive industry. In the course of our study we found that inscribed in Flight Centre were two, differing discourses which appear to co,exist in creative tension throughout the organization. One discourse is competitive individualism and the other collaborative teamwork. Our paper focuses on how Flight Centre has made use of multiple discourses such as these in the process of achieving competitive advantage, and how people manage the differing discursive logics which confront them on a day,to,day basis. The paper proceeds by identifying the social and textual practices which constitute each discourse. It then establishes the discursive co,existence and tension which exists between the two discourses. Study is made of the conditions under which this discursive co,existence is disrupted. We then identify the interpretative routines and practices through which organizational actors maintain and reproduce discursive co,existence. Our paper concludes by considering a variety of implications of studying multiple discourses in organizations. [source]

    An investigation of experienced secondary science teachers' beliefs about inquiry: An examination of competing belief sets

    Carolyn S. Wallace
    The purpose of this study was to investigate the beliefs of six experienced high school science teachers about (1) what is successful science learning; (2) what are the purposes of laboratory in science teaching; and (3) how inquiry is implemented in the classroom. An interpretive multiple case study with an ethnographic orientation was used. The teachers' beliefs about successful science learning were substantively linked to their beliefs about laboratory and inquiry implementation. For example, two teachers who believed that successful science learning was deep conceptual understanding, used verification labs primarily to illustrate these concepts and used inquiry as a type of isolated problem-solving experience. Another teacher who believed that successful science learning was enculturation into scientific practices used inquiry-based labs extensively to teach the practices of science. Tension in competing beliefs sets and implications for reform are discussed. ? 2004 Wiley Periodicals, Inc. J Res Sci Teach 41: 936-960, 2004. [source]

    An Examination of Surface Tension of Binary Lithium Borate Melts as a Function of Composition and Temperature

    Xiumei Shi
    Surface tensions of xLi2O,(1,x)B2O3 melts, where 0,x,0.68, have been measured systematically with a ring method from respective liquidus temperatures up to about 1450 K. For all of the investigated melts, the relationship between surface tension and temperature can be well described by quadratic polynomial functions. With increasing Li2O content, surface tension monotonously increased, whereas the temperature coefficient of surface tension increased slowly up to about x=0.1, changed sign from positive to negative at about x=0.2, and then remained negative with further increasing Li2O content. Together with the physical properties reported in our previous work, such as density, temperature coefficient of density, and volume expansion coefficient, etc., both surface tension and temperature coefficient of surface tension have been comparatively plotted as a function of Li/B molar ratio. Differentiated from the inflections of slope in the plots of physical properties vs. Li/B molar ratio, three characteristic regions have been found in the melts of this system. Within different regions, different effects of temperature and concentration on the physical properties of melts have been observed. [source]

    Density, Surface Tension, and Viscosity of PbO-B2O3 -SiO2 Glass Melts

    Shigeru Fujino
    The density, surface tension, and viscosity of the melts from the PbO-B2O3 -SiO2 system have been measured at temperatures in the range 1073,1473 K. The effect of composition on these properties was also investigated. The density of the melt was found to increase linearly with increasing PbO content. Molar volume was derived from the density data, and its deviation from the additivity of partial molar volumes was calculated. These deviations in molar volume from those obtained from additivity rules have been used along with the ratio of various coordination numbers of boron (as reported by Bray) to discuss the structure of the melts. The surface tension was found to decrease with decreasing SiO2/B2O3 ratio, and to increase in the range of the PbO content between 30 and 60 mol%, showing a maximum at ,60 mol% PbO, and then decreased with further additions. This result suggested that the surface tension would be affected primarily by the B2O3 content in the range of the PbO content between 30,60 mol%, and mainly by the PbO content in the range of the PbO content >60 mol%, respectively. The viscosity of the melt was found to decrease linearly with increasing PbO content. The results obtained indicate that the increase in viscosity with B2O3 was half that of SiO2 (on a molar basis), and an empirical equation has been proposed for the viscosity as a function of mole fraction. [source]

    Tension and stress in the rat and rabbit stomach are location- and direction-dependent

    J. Zhao
    Abstract, Distension studies in the stomach are very common. It is assumed in pressure,volume (barostat) studies of tone and tension in the gastric fundus that the fundus is a sphere, i.e. that the tension in all directions is identical. However, the complex geometry of the stomach indicates a more complex mechanical behaviour. The aim of this study was to determine uniaxial stress,strain properties of gastric strips obtained from rats (n = 12) and rabbits (n = 10). Furthermore, we aimed to study the gastric zero-stress state since the stomach is one of the remaining parts of the gastrointestinal tract where residual strain studies have not been conducted. Longitudinal strips (in parallel with the lesser curvature) and circumferential strips (perpendicular to the lesser curvature) were cut from the gastric fundus (glandular part) and forestomach (non-glandular part). The residual stress was evaluated as bending angles (unit: degree per unit length and negative when bending outwards). The residual strain was computed from the change in length between the zero-stress state and no-load state. The stress,strain test was performed using a tensile test machine. The thickness and width of each strip were measured from digital images. The strips data were compared with data obtained in the intact stomach in vitro. Most residual stresses and strains were bigger in the glandular part than in the forestomach, and in general the rat stomach had higher values than the rabbit stomach. The glandular strips were stiffer than the forestomach strips and the longitudinal glandular strips were stiffer than the circumferential glandular strips (P < 0.05). The gastric strips were stiffer in rats than in rabbits (P < 0.01). The data obtained in the intact rat stomach confirmed the strips data and indicated that those were obtained in the physiological range. In conclusion, the biomechanical properties of the gastric strips from the rat and rabbit are location-dependent, direction-dependent and species-dependent. The assumption in physiological pressure,volume studies that the stomach is a sphere with uniform tension is not valid. Three-dimensional geometric data obtained using imaging technology and mechanical data are needed for evaluation of the stomach function. [source]

    On a Tension in Diamond's Account of Tractarian Nonsense

    Ben Vilhauer
    First page of article [source]

    Structure,properties relations in titanium-based thermoplastic fiber,metal laminates

    POLYMER COMPOSITES, Issue 3 2006
    P. Cortés
    This paper investigates the interfacial, tensile, and fatigue properties of a titanium alloy fiber,metal laminate (Ti-FML) based on woven glass-fiber-reinforced polyetherimide (GF/PEI). Initial tests, using the single cantilever beam (SCB) geometry have shown that it is not necessary to surface treat the titanium alloy in order to achieve a high value of metal,composite interfacial fracture toughness. Tensile tests have shown that the mechanical properties of the FML lie between those offered by its constituent materials. Tension,tension fatigue tests have shown that the fatigue lives of these laminates are superior to those offered by the plain titanium alloy. The mechanical properties of this glass fiber/PEI FML have also been compared with those offered by an FML based on a unidirectional carbon-fiber-reinforced polyetheretherketone (CF/PEEK) composite. Here, it has been shown that although the fatigue properties of this woven GF/PEI composite are inferior to those of the CF/PEEK FML, they do offer a higher temperature capability due to the higher glass transition temperature of the PEI matrix. Polym. Compos. 27:264,270, 2006. © 2006 Society of Plastics Engineers. [source]

    God in the Dock: Dialogic Tension in the Psalms of Lament , Carleen Mandolfo

    Tyler Mayfield
    No abstract is available for this article. [source]

    Optimum Tension for Partial Ossicular Replacement Prosthesis Reconstruction in the Human Middle Ear,

    THE LARYNGOSCOPE, Issue 2 2004
    David P. Morris BSc
    Abstract Objective: Hearing results from ossiculoplasty are unpredictable. There are many potentially modifiable parameters. One parameter that has not been adequately investigated in the past is the effect of tension on the mechanical functioning of the prosthesis. Our goal was to investigate this parameter further, with the hypothesis that the mechanical functioning of partial ossicular replacement prostheses (PORP) from the stapes head to the eardrum will be affected by the tension that they are placed under. Methods: Fresh temporal bones were used to reconstruct a missing incus defect with a PORP-type prosthesis. Three different lengths of PORP were used, and the stapes vibrations were measured with a laser Doppler vibrometer using a calibrated standard sound in the ear canal. Eight temporal bones were used. Results: Tension had a very significant effect on stapes vibration. In general, loose prostheses resulted in the best overall vibration transmission. The effects were most marked at the lower frequencies. There was a slight advantage to tight prostheses in the higher frequencies, but much less than the decrement in lower frequencies with tight prostheses. Conclusion: In ossicular reconstruction, best stapes vibration results in our model are achieved by shorter prostheses, which result in lower tension. [source]

    The ligamentum olecrani of the Elbow Joint in Dogs and Cats

    E. Engelke
    The olecranon ligament (ligamentum olecrani) is described as an elastic ligament of the elbow joint in carnivores that tenses the caudomedial part of the joint capsule. The aim of the study was to compare the course and the microscopic structure of the ligament in dogs and cats. The elbow regions of 25 dogs and 15 cats were dissected to examine the topography of the ligament in extension and flexion. Furthermore, the olecranon ligaments of five dogs and five cats were studied using routine histological methods. Additional sections were stained with Resorcin,Fuchsin and Orcein to detect elastic fibres. In both species the olecranon ligament originates at the lateral surface of the epicondylus medialis humeri and inserts at the cranial crest of the olecranon extending distally to the roof of the processus anconeus. Tension of the ligament only occurs when the elbow joint is flexed maximally. This tension is increased by a slight supination of the forearm, which takes place automatically in this joint position. In dogs the ligament is long (30,40 mm in medium sized breeds) and relatively slim (approx. 2,4 mm). In cats the ligament is short (10,12 mm) and relatively strong (5,8 mm). The histological examination of the olecranon ligament shows all signs of a tight collagenous ligament with a negligible amount of elastic fibres. The olecranon ligament helps to limit the maximal flexion of the elbow joint. In addition, it controls a slight lateral movement of the processus anconeus during the automatic supination of the antebrachial bones in extreme flexion of the elbow joint. [source]

    Effect of line shooter and mainline tension on the sink rates of pelagic longlines and implications for seabird interactions

    Graham Robertson
    Abstract 1. The likelihood that seabirds will be hooked and drowned in longline fisheries increases when baited hooks sink slowly. Fishermen target different fishing depths by setting the mainline through a line shooter, which controls the tension (or slackness) in the line. An experiment was conducted in Australia's pelagic longline fishery to test the hypothesis of no difference in sink rates of baited hooks attached to mainline set under varying degrees of tension. 2. Mainline was set in three configurations typically used in the fishery: (a) surface set tight with no slackness astern; (b) surface set loose with 2,s of slack astern; and (c) deep set loose with 7,s of slack astern. 3. Tension on the mainline had a powerful effect on sink rates. Baited hooks on branch lines attached to tight mainlines reached 2,m depth nearly twice as fast as those on the two loose mainline tensions, averaging 5.8,s (0.35,m,s,1) compared with 9.9,s (0.20,m,s,1) and 11.0,s (0.18,m,s,1) for surface set loose and deep set loose tensions, respectively. 4. The likely reason for the difference is propeller turbulence. Tight mainline entered the water aft of the area affected by turbulence whereas the two loose mainlines and the clip ends of branch lines were set directly into it about 1,m astern of the vessel. The turbulence presumably slowed the sink rates of baited hooks at the other end of the branch lines. 5. The results suggest that mainline deployed with a line shooter (as in deep setting) into propeller turbulence at the vessel stern slows the sink rates of baited hooks, potentially increasing their availability to seabirds. Unless mainline can be set to avoid propeller turbulence the use of line shooters for deep setting should not be promoted as an effective deterrent to seabirds. Copyright © 2010 John Wiley & Sons, Ltd. [source]

    Acid-Base Balance and Oxygen Tension During Dialysis in Uremic Patients With Chronic Obstructive Pulmonary Disease

    ARTIFICIAL ORGANS, Issue 12 2008
    Simone Manca-Di-Villahermosa
    Abstract Recent reports on the effects of dialysis on acid-base balance and metabolic acidosis correction in end-stage renal disease (ESRD) patients with chronic obstructive pulmonary disease (COPD) are lacking. Here, we compared acid-base balance and blood gasses among 14 patients with established COPD (group A) and eight patients with normal respiratory function (group B). The two groups were homogeneous for age, time on dialysis, and male/female ratio. At the beginning of dialysis, acid-base balance and blood gasses were comparable between patients of groups A and B. A significant difference between groups was observed only in pCO2 at 20 min, together with a delay in pH increase. Effective correction of acidosis was reported at the end of dialysis and is not significantly affected by COPD. Nevertheless, weight loss must be carefully monitored in these patients in order to prevent hyperhydration and worsening of respiratory function. [source]

    Improvement of Metabolic Performance of Cultured Hepatocytes by High Oxygen Tension in the Atmosphere

    ARTIFICIAL ORGANS, Issue 1 2001
    Kennichi Yanagi
    Abstract: Maintaining metabolic functions of cultured hepatocytes at higher levels is an essential requirement for the development of a bioartificial liver. We investigated the effect of oxygen tension (10,40%) of the medium on immobilization efficiency and metabolic functions of cultured hepatocytes obtained from a rat for up to 4 days. Immobilization efficiencies of cultures in 10% oxygen showed a significantly lower value from those for the other conditions. The ammonium metabolic rate and the albumin secretion rate were significantly improved with an increase of dissolved oxygen tension for up to 2 days. These values remained similar in the later stage of the culture. The urea secretion rate showed similar values in all conditions. In conclusion, higher oxygen tension improved immobilization efficiency and metabolic functions of cultured rat hepatocytes in the earlier stage of culture for up to 2 days. [source]

    Comparison of girth materials, girth tensions and their effects on performance in racehorses

    Objective To compare the effect of girth materials and commonly used girth tensions on athletic performance of racehorses and to test the length tension properties of commercially available girths. Procedure Seven horses were exercised at speeds to produce 95% of maximal heart rates on 15 occasions using a randomised block design, and girthed with 5 different girths at 3 nominal tensions of 6, 12 or 18 kg. The girths used were a standard elastic race girth, an ,American' elastic race girth, an elastic race girth twice the normal width, a standard canvas race girth and a canvas race girth at twice the normal width. Tension in the girth was recorded continuously using an in-line load cell connected to a physiograph. Horses ran to fatigue on a treadmill inclined at 10% slope. Tensions were measured at peak inhalation (T/inh) and exhalation (T/exh), recorded at rest (rest) and during exercise (ex). An analysis of variance was used to compare the mean run to fatigue times (RTFT) between girth types and tensions, multiple pair-wise comparisons were then carried out using Tukey's test where significant differences were found. The length-tension relationships of five commercially available girths for training and racing of Thoroughbred racehorses were studied by the application of standardized weights in series to multiple samples of each type of girth. Measurements were taken in a controlled environment and analysis of variance was used to compare the means for length-tension of each girth type. Results The elastic and the ,American' elastic girths produced significantly longer RTFT when compared to the standard canvas girth (P=0.01 and P = 0.001 respectively). Also girths tensioned at Texhrest 6 kg and Texhrest 12 kg produced significantly longer RTFT than when girthed at Texhrest 18 kg (P=0.03 and P = 0.08 respectively). There were significant differences between the commercially available girth types at each tension (P < 0.05), but differences were not significant between girths of the same type. Girths with an elastic component reached their peak for maximum extension at 14.5 kg and thereafter their extension declined. Conclusion The type of girth and the tension at which it is applied affects athletic performance. Lower girth tensions and the use of elastic materials in the girth would appear to optimise performance. However according to this study and our previous study, none of the commercially available girths studied would adequately protect against the potentially detrimental effects of overtightening on athletic performance. [source]

    Effect of Sodium Halide on Dynamic Surface Tension of a Cationic Surfactant

    Lü Feng-Feng
    Abstract The equilibrium and dynamic surface tension (DST) of the novel cationic surfactant, 3-(p -nonylphenoxy)-2-hydroxylpropyl trimethyl ammonium bromide, abbreviated as RTAB, were studied. The effect of sodium halide such as NaCl, NaBr and NaI on the DST behavior of the RTAB solution below its CMC was studied in detail. Due to the preferential adsorption, the effect of hydration and salting out, the ability to reduce the DST values at the same concentration was in the order of NaI>NaBr>NaCl. Attributed to its high surface activity, the equilibrium time of the DST of the surfactant solution was insensitive to the ionic strength. [source]