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1.
Disabil Rehabil Assist Technol ; 15(2): 225-237, 2020 02.
Article in English | MEDLINE | ID: mdl-30729844

ABSTRACT

Purpose: To provide empirical evidence on learning barriers and facilitators in instructional science and engineering laboratory settings from a national survey on students with physical disabilities (SwD-P).Methods: A nationwide self-report survey, the Full Participation Science and Engineering Accessibility (FPSEA), was disseminated online via Qualtrics. Approximately 1200 organizations and universities across the United States were contacted through purposive sampling. Descriptive statistics were primarily used for the analysis of the results.Results: Survey findings reveal that students experience a wide range of limitations to full participation in the laboratory, from entering the laboratory (25%) to being given passive roles (50%). Additionally, while 66% of respondents indicated that instructors were willing to help SwD-P participate in science and engineering (S&E) laboratories, 16.8% were not willing to do so, and 47% SwD-P felt that practices were not in place to provide accommodations. The survey also reveals a range of facilitators such as elevators, ramps, accessible course materials and peer assistance. Most respondents (74%) also indicated that peers were helpful in completing laboratory tasks.Conclusion: This survey provides empirical evidence that was previously voiced through non-empirical information in the literature. Participants cited barriers such as inappropriate accommodations and instructors' negative viewpoints, as well as gaining access to facilities even after the enactment of the Americans with Disabilities Act (ADA). These findings suggest that while ADA has lessened some barriers to SwD-P, barriers remain in using the laboratory space. The FPSEA survey fills the gap in finding barriers and facilitators to using S&E laboratories from the SwD-P's perspective.Implications for RehabiliationBarriers students with disabilities encounter in science and engineering (S&E) laboratory environments remain unclear.The FPSEA survey fills the gap in finding barriers and facilitators to using S&E laboratories from the SwD-P's perspective.The FPSEA survey allows former and current SwD-P to share their experiences using a postsecondary S&E instructional laboratory.


Subject(s)
Architectural Accessibility , Disabled Persons , Engineering/education , Laboratories , Students , Adolescent , Adult , Aged , Female , Humans , Male , Middle Aged , Surveys and Questionnaires , United States , Universities , Young Adult
2.
Disabil Rehabil Assist Technol ; 14(7): 692-709, 2019 10.
Article in English | MEDLINE | ID: mdl-30317937

ABSTRACT

Purpose: The purpose of this study is to address the development of the Full Participation Science and Engineering Accessibility (FPSEA) self-report survey that gathers experiences from students with physical disabilities (SwD-P) using a postsecondary laboratory and to evaluate the survey's stability. Methods: Survey items were generated from an extensive literature review and recommendations articulated by experts. Think-aloud sessions and content validity index (CVI) were used to determine survey content validity and help finalize survey items. Individuals with physical disabilities (n = 20) who have taken a postsecondary science or engineering laboratory course completed the survey and took it again 10-14 days apart. The test-retest reliability was assessed using Spearman Rho coefficients for Likert-scale items, Chi-square and Fisher's exact test for the dichotomous items. Missing data completely at random (MCAR) test was computed before reliability data analysis. Results: Each sub-item passed the MCAR test, indicating that the data are missing completely at random and can be imputed to perform the analysis. Reliability analysis was completed on 20 individuals. The FPSEA had good content reliability: the item-level CVI of items kept ranged from 0.86 to 1. The scale-level CVI was 0.94. Stability was demonstrated with adequate Spearman correlation ranged from 0.56 to 0.86. Conclusions: No previous survey had been developed linking SwD-P and the postsecondary science and engineering (S&E) laboratory setting prior to this work. Overall, FPSEA is reliable and stable for reporting the barriers and facilitators to use S&E laboratories from the SwD-P's perspective. Implications for rehabilitation The barriers students with disabilities encounter in S&E laboratory environments are largely unknown. The FPSEA survey may help identify barriers and facilitators to using S&E laboratories for SwD-P. The FPSEA Survey allows former and current SwD-P to share their experiences using a postsecondary S&E instructional laboratory.


Subject(s)
Architectural Accessibility , Disabled Persons/psychology , Engineering/education , Laboratories , Science/education , Humans , Psychometrics , Reproducibility of Results , Surveys and Questionnaires
3.
Int J Sports Med ; 37(1): 30-5, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26509373

ABSTRACT

Our purpose was to examine the influence of glove type on kinetic and spatiotemporal parameters at the handrim in elite wheelchair racers. Elite wheelchair racers (n=9) propelled on a dynamometer in their own racing chairs with a force and moment sensing wheel attached. Racers propelled at 3 steady state speeds (5.36, 6.26 & 7.60 m/s) and performed one maximal effort sprint with 2 different glove types (soft & solid). Peak resultant force, peak torque, impulse, contact angle, braking torque, push time, velocity, and stroke frequency were recorded for steady state and sprint conditions. Multiple nonparametric Wilcoxon matched pair's tests were used to detect differences between glove types, while effect sizes were calculated based on Cohen's d. During steady state trials, racers propelled faster, using more strokes and larger contact angle, while applying less impulse with solid gloves compared to soft gloves. During the sprint condition, racers achieved greater top end velocities, applying larger peak force, with less braking torque with solid gloves compared to soft gloves. Use of solid gloves may provide some performance benefits to wheelchair racers during steady state and top end velocity conditions.


Subject(s)
Athletic Performance/physiology , Gloves, Protective , Sports Equipment , Sports/physiology , Wheelchairs , Adult , Biomechanical Phenomena , Equipment Design , Female , Hand/physiology , Humans , Kinetics , Male , Pilot Projects , Torque , Young Adult
4.
Clin Radiol ; 69(12): 1235-43, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25439186

ABSTRACT

AIM: To evaluate the impact of staging FDG PET-CT on the initial management of patients with locally advanced cervical carcinoma (LACC) and any prognostic variables predicting survival. MATERIALS AND METHODS: Retrospective analysis of consecutive patients undergoing FDG PET-CT for staging of LACC in a single tertiary referral centre, between April 2008 and August 2011. Comparison was made between MRI and PET-CT findings and any subsequent impact on treatment intent or radiotherapy planning was evaluated. RESULTS: Sixty-three patients underwent FDG PET-CT for initial staging of LACC. Major impact on management was found in 20 patients (32%), a minor impact in five (8%), and no impact in 38 (60%). In those patients where PET-CT had a major impact, 12 had more extensive local nodal involvement, five had occult metastatic disease, two had synchronous tumours, and one patient had equivocal lymph nodes on MRI characterized as negative. PET-positive nodal status at diagnosis was found to be a statistically significant predictor of relapse-free survival (p < 0.05). CONCLUSION: Staging FDG PET-CT has a major impact on the initial management of approximately one-third of patients with LACC by altering treatment intent and/or radiotherapy planning. PET-defined nodal status is a poor prognostic indicator.


Subject(s)
Fluorodeoxyglucose F18 , Multimodal Imaging/methods , Positron-Emission Tomography/methods , Radiopharmaceuticals , Tomography, X-Ray Computed/methods , Uterine Cervical Neoplasms/diagnosis , Uterine Cervical Neoplasms/therapy , Adult , Aged , Cervix Uteri/diagnostic imaging , Female , Humans , Middle Aged , Neoplasm Staging , Retrospective Studies , Uterine Cervical Neoplasms/pathology , Young Adult
5.
J Wound Care ; 23(11): 570, 572-4, 576-80 passim, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25375405

ABSTRACT

Following confirmation of the presence of biofilms in chronic wounds, the term biofilm became a buzzword within the wound healing community. For more than a century pathogens have been successfully isolated and identified from wound specimens using techniques that were devised in the nineteenth century by Louis Pasteur and Robert Koch. Although this approach still provides valuable information with which to help diagnose acute infections and to select appropriate antibiotic therapies, it is evident that those organisms isolated from clinical specimens with the conditions normally used in diagnostic laboratories are mainly in a planktonic form that is unrepresentative of the way in which most microbial species exist naturally. Usually microbial species adhere to each other, as well as to living and non-living surfaces, where they form complex communities surrounded by collectively secreted extracellular polymeric substances (EPS). Cells within such aggregations (or biofilms) display varying physiological and metabolic properties that are distinct from those of planktonic cells, and which contribute to their persistence. There are many factors that influence healing in wounds and the discovery of biofilms in chronic wounds has provided new insight into the reasons why. Increased tolerance of biofilms to antimicrobial agents explains the limited efficacy of antimicrobial agents in chronic wounds and illustrates the need to develop new management strategies. This review aims to explain the nature of biofilms, with a view to explaining their impact on wounds.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Biofilms/drug effects , Wound Infection/drug therapy , Wounds and Injuries/drug therapy , Wounds and Injuries/microbiology , Drug Resistance, Bacterial , Humans , Wound Healing
6.
Int J Sports Med ; 35(5): 424-31, 2014 May.
Article in English | MEDLINE | ID: mdl-24081621

ABSTRACT

The purpose of this study was to compare court-movement variables and physiological responses to wheelchair tennis match-play when using low vs. standard compression tennis balls. Eleven wheelchair basketball players were monitored during repeated bouts of tennis (20 min) using both ball types. Graded and peak exercise tests were completed. For match-play, a data logger was used to record distance and speed. Individual linear heart rate oxygen consumption relationships were used to estimate match-play oxygen uptake. Significant main effects for ball type revealed that total distance (P<0.05), forward distance (P<0.05), and average speed (P<0.05) were higher for play using a low-compression ball. A lower percentage of total time was spent stationary (P<0.001), with significantly more time spent at speeds of 1-1.49 (P<0.05), 1.5-1.99 (P<0.05) and 2.0-2.49 (P<0.05) m ∙ sec(-1) when using the low-compression ball. Main effects for physiological variables were not significant. Greater total and forward distance, and higher average speeds are achieved using a low-compression ball. The absence of any difference in measured HR and estimated physiological responses would indicate that players move further and faster at no additional mean physiological cost. This type of ball will be useful for novice players in the early phases of skill development.


Subject(s)
Athletic Performance/physiology , Sports Equipment , Tennis/physiology , Wheelchairs , Adolescent , Adult , Energy Metabolism/physiology , Female , Heart Rate/physiology , Humans , Male , Movement/physiology , Oxygen Consumption/physiology , Task Performance and Analysis , Young Adult
7.
Spinal Cord ; 51(9): 705-9, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23689386

ABSTRACT

STUDY DESIGN: Validation. OBJECTIVES: The primary aim of this study was to develop and evaluate activity classification algorithms for a multisensor-based SenseWear (SW) activity monitor that can recognize wheelchair-related activities performed by manual wheelchair users (MWUs) with spinal cord injury (SCI). The secondary aim was to evaluate how the accuracy in activity classification affects the estimation of energy expenditure (EE) in MWUs with SCI. SETTING: University-based laboratory. METHODS: Forty-five MWUs with SCI wore a SW on their upper arm and participated in resting, wheelchair propulsion, arm-ergometery and deskwork activities. The investigators annotated the start and end of each activity trial while the SW collected multisensor data and a portable metabolic cart collected criterion EE. Three methods including linear discriminant analysis, quadratic discriminant analysis (QDA), and Naïve Bayes (NB) were used to develop classification algorithms for four activities based on the training data set from 36 subjects. RESULTS: The classification accuracy was 96.3% for QDA and 94.8% for NB when the classification algorithms were tested on the validation data set from nine subjects. The average EE estimation errors using the activity-specific EE prediction model were 5.3±21.5% and 4.6±22.8% when the QDA and NB classification algorithms were applied, respectively, as opposed to 4.9±20.7% when 100% classification accuracy was assumed. CONCLUSION: The high classification accuracy and low EE estimation errors suggest that the SW can be used by researchers and clinicians to classify and estimate the EE for the four activities tested in this study among MWUs with SCI.


Subject(s)
Monitoring, Ambulatory/instrumentation , Motor Activity/physiology , Spinal Cord Injuries , Wheelchairs , Adult , Algorithms , Arm/physiology , Artificial Intelligence , Bayes Theorem , Data Interpretation, Statistical , Energy Metabolism , Ergometry , Female , Humans , Male , Monitoring, Ambulatory/methods , Paraplegia/physiopathology , Predictive Value of Tests , Quadriplegia/physiopathology , Reproducibility of Results
8.
J Appl Microbiol ; 115(1): 86-90, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23594187

ABSTRACT

AIMS: The aim of this study was to determine whether manuka honey affected siderophore production by three strains of Pseudomonas aeruginosa. METHODS AND RESULTS: The minimum inhibitory concentration (MIC) of manuka honey against each of the test bacteria was determined. The effect of manuka honey on siderophore production by three strains of Ps. aeruginosa was investigated using the Chrome azurol S assay (CAS) and CAS-agar plates. Manuka honey at ½ and » of the MIC for each strain led to reduced production of siderophores (1·3-2·2-fold less) which was found to be statistically significant when compared to the untreated control. CONCLUSIONS: Manuka honey effectively inhibited siderophore production by all three strains of Ps. aeruginosa used in this study. This suggests that manuka honey may impact on bacterial iron homoeostasis and identified a new target for manuka honey in Ps. aeruginosa. SIGNIFICANCE AND IMPACT OF STUDY: Pseudomonas aeruginosa is an opportunistic human pathogen that can cause acute, life-threatening or persistent wound infections. Part of the virulence repertoire of this micro-organism includes the ability to sequester iron from the host during infection by the synthesis and secretion of siderophores. Manuka honey may limit wound infection by Ps. aeruginosa by limiting its ability to capture iron. This is the first time this mechanism has been investigated.


Subject(s)
Anti-Bacterial Agents/pharmacology , Honey , Pseudomonas aeruginosa/drug effects , Siderophores/biosynthesis , Iron/metabolism , Leptospermum , Microbial Sensitivity Tests , Pseudomonas aeruginosa/growth & development , Pseudomonas aeruginosa/metabolism
9.
Assist Technol ; 24(2): 102-9, 2012.
Article in English | MEDLINE | ID: mdl-22876732

ABSTRACT

Surface characteristics of a cross slope can impact the ease with which a manual wheelchair (MWC) user propels across a surface. The purpose of this research was two-fold. Phase I of this research surveyed MWC users to identify cross slope scenarios that they reported to be more difficult to traverse compared to other common driving obstacles. Our survey results showed that, overall, cross slopes were harder to propel across than narrow and manual doors, and cross-slopes in inclement weather conditions were equal or more difficult than gravel and rough-surfaces. Cross slopes with severe angles and those with compound angles (slope with cross-slope) were the most difficult to traverse. Phase II focused on identifying the responses (e.g., avoid, explore alternative, experience a sense of insecurity, no effect) people had when viewing pictures of various cross-slopes scenarios (e.g., narrow space, compound angles, extreme weather) that wheelchair users encounter. These results showed that people reported that they would avoid or feel insecure on some cross-sloped surfaces, like the weather, that are not within our control, others, like compound angle and curb-cuts on slopes, that can be addressed in the construction of pathways or sidewalks.


Subject(s)
Architectural Accessibility/methods , Construction Materials , Locomotion , Wheelchairs , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Surveys and Questionnaires , United States
10.
Br J Radiol ; 85(1009): 61-8, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22190750

ABSTRACT

OBJECTIVES: MRI is the preferred staging modality for rectal carcinoma patients. This work assesses the CT-MRI co-registration accuracy of four commercial rigid-body techniques for external beam radiotherapy treatment planning for patients treated in the prone position without fiducial markers. METHODS: 17 patients with biopsy-proven rectal carcinoma were scanned with CT and MRI in the prone position without the use of fiducial markers. A reference co-registration was performed by consensus of a radiologist and two physicists. This was compared with two automated and two manual techniques on two separate treatment planning systems. Accuracy and reproducibility were analysed using a measure of target registration error (TRE) that was based on the average distance of the mis-registration between vertices of the clinically relevant gross tumour volume as delineated on the CT image. RESULTS: An automated technique achieved the greatest accuracy, with a TRE of 2.3 mm. Both automated techniques demonstrated perfect reproducibility and were significantly faster than their manual counterparts. There was a significant difference in TRE between registrations performed on the two planning systems, but there were no significant differences between the manual and automated techniques. CONCLUSION: For patients with rectal cancer, MRI acquired in the prone treatment position without fiducial markers can be accurately registered with planning CT. An automated registration technique offered a fast and accurate solution with associated uncertainties within acceptable treatment planning limits.


Subject(s)
Carcinoma/diagnosis , Carcinoma/radiotherapy , Magnetic Resonance Imaging , Radiotherapy Planning, Computer-Assisted/methods , Rectal Neoplasms/diagnosis , Rectal Neoplasms/radiotherapy , Tomography, X-Ray Computed , Humans , Reproducibility of Results
11.
Philos Trans A Math Phys Eng Sci ; 369(1941): 1626-39, 2011 Apr 28.
Article in English | MEDLINE | ID: mdl-21422018

ABSTRACT

From analysis of the in-plane resistivity ρ(ab)(T) of La(2-x)Sr(x)CuO(4), we show that normal state transport in overdoped cuprates can be delineated into two regimes in which the electrical resistivity varies approximately linearly with temperature. In the low-temperature limit, the T-linear resistivity extends over a very wide doping range, in marked contrast to expectations from conventional quantum critical scenarios. The coefficient of this T-linear resistivity scales with the superconducting transition temperature T(c), implying that the interaction causing this anomalous scattering is also associated with the superconducting pairing mechanism. At high temperatures, the coefficient of the T-linear resistivity is essentially doping independent beyond a critical doping p(crit)=0.19 at which the ratio of the two coefficients is maximal. Taking our cue from earlier thermodynamic and photoemission measurements, we conclude that the opening of the normal-state pseudogap at p(crit) is driven by the loss of coherence of anti-nodal quasi-particles at low temperatures.

12.
Eur J Clin Microbiol Infect Dis ; 30(2): 167-71, 2011 Feb.
Article in English | MEDLINE | ID: mdl-20936493

ABSTRACT

The purpose of this study was to investigate the effects of manuka honey on the structural integrity of Pseudomonas aeruginosa ATCC 27853. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of manuka honey for P. aeruginosa were determined by a microtitre plate method, and the survival of bacteria exposed to a bactericidal concentration of manuka honey was monitored. The effect of manuka honey on the structure of the bacteria was investigated using scanning and transmission electron microscopy (SEM and TEM, respectively). The MIC and MBC values of manuka honey against P. aeruginosa were 9.5% (w/v) and 12% (w/v) respectively; a time-kill curve demonstrated a bactericidal rather than a bacteriostatic effect, with a 5 log reduction estimated within 257 min. Using SEM, loss of structural integrity and marked changes in cell shape and surface were observed in honey-treated cultures. With TEM, these changes were confirmed, and evidence of extensive cell disruption and lysis was found. Manuka honey does not induce the same structural changes in P. aeruginosa as those observed in staphylococci. Our results indicate that manuka honey has the potential to be an effective inhibitor of P. aeruginosa.


Subject(s)
Anti-Bacterial Agents/pharmacology , Honey , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/ultrastructure , Humans , Microbial Sensitivity Tests , Microbial Viability/drug effects , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission
13.
Eur J Clin Microbiol Infect Dis ; 29(10): 1237-41, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20549529

ABSTRACT

Clinical use of honey in the topical treatment of wounds has increased in Europe and North America since licensed wound care products became available in 2004 and 2007, respectively. Honey-resistant bacteria have not been isolated from wounds, but there is a need to investigate whether honey has the potential to select for honey resistance. Two cultures of bacteria from reference collections (Staphylococcus aureus NCTC 10017 and Pseudomonas aeruginosa ATCC 27853) and four cultures isolated from wounds (Escherichia coli, methicillin-resistant S. aureus (MRSA), Pseudomonas aeruginosa and S. epidermidis) were exposed to sub-lethal concentrations of manuka honey in continuous and stepwise training experiments to determine whether the susceptibility to honey diminished. Reduced susceptibilities to manuka honey in the test organisms during long-term stepwise resistance training were found, but these changes were not permanent and honey-resistant mutants were not detected. The risk of bacteria acquiring resistance to honey will be low if high concentrations are maintained clinically.


Subject(s)
Anti-Infective Agents, Local/pharmacology , Drug Resistance, Bacterial , Honey , Drug Tolerance , Escherichia coli/drug effects , Escherichia coli/isolation & purification , Humans , Microbial Sensitivity Tests , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/isolation & purification , Serial Passage , Staphylococcus aureus/drug effects , Staphylococcus aureus/isolation & purification , Staphylococcus epidermidis/drug effects , Staphylococcus epidermidis/isolation & purification
14.
Eur J Clin Microbiol Infect Dis ; 29(1): 45-50, 2010 Jan.
Article in English | MEDLINE | ID: mdl-19813035

ABSTRACT

The purpose of this study was to investigate the effect of manuka honey on Staphylococcus aureus in order to identify the intracellular target site. The mode of inhibition of manuka honey against S. aureus NCTC 10017 was investigated by determining the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and the effect of time on viability. Structural changes were observed by scanning (SEM) and transmission electron microscopy (TEM) of cells suspended for 4 h at 37 degrees C in 0.05 mM Tris buffer containing 10% (w/v) manuka honey and were compared to cells in buffer alone or buffer containing 10% (w/v) artificial honey (to assess osmotic damage). A bactericidal mode of inhibition for manuka honey on S. aureus was established. Marked structural changes in honey-treated cells were seen only with TEM, where a statistically significant increase in the number of whole cells with completed septa compared to untreated cells were observed (P < 0.05). Structural changes found with TEM suggest that honey-treated cells had failed to progress normally through the cell cycle and accumulated with fully formed septa at the point of cell division without separating. Sugars were not implicated in this effect. The staphylococcal target site of manuka honey involves the cell division machinery.


Subject(s)
Anti-Bacterial Agents/toxicity , Honey/toxicity , Staphylococcus aureus/drug effects , Cell Division/drug effects , Microbial Sensitivity Tests , Microbial Viability , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , Staphylococcus aureus/ultrastructure
15.
Ann Oncol ; 20(6): 977-84, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19153113

ABSTRACT

BACKGROUND: Sentinel node biopsy (SNB) of internal mammary nodes (IMNs) in breast cancer is controversial. Most centers rarely identify IMN on lymphoscintigraphy but others report up to 45% of cases. Controversy relates to the technique of lymphatic mapping, safety of IMN SNB, the significance of positive IMN, and potential to impact survival. METHODS: Assessment of drainage rates from two unrelated nuclear medicine departments' databases. Review of related literature. RESULTS: High-resolution lymphoscintigraphy results in IMN drainage in one-third of breast cancers. There is a learning curve for the technique. In 1754 consecutive cases, internal mammary drainage occurred in 53% of medial tumors, 37% midline tumors and 24% of lateral tumors (overall 34%). Extended radical mastectomy series also demonstrate the (approximately) 1/3 ratio when comparing IMN positivity rates to axillary node positivity rates (18.8% : 48.3%) and in node-positive patients (31% : 100%). The management altering potential of IMN assessment and potential survival impact are discussed. CONCLUSIONS: IMN mapping gives information that alters management in up to one-third of cases. These rates of IMN drainage are reproducible and reflect lymphatic density and anatomy of the breast. A priority need exists to establish a collaborative clinical trial to clarify the value of IMN assessment.


Subject(s)
Breast Neoplasms/diagnostic imaging , Lymph Nodes/diagnostic imaging , Breast Neoplasms/pathology , Female , Humans , Lymph Nodes/pathology , Lymphatic Metastasis , Radionuclide Imaging , Thorax
16.
Science ; 323(5914): 603-7, 2009 Jan 30.
Article in English | MEDLINE | ID: mdl-19074310

ABSTRACT

The presence or absence of a quantum critical point and its location in the phase diagram of high-temperature superconductors have been subjects of intense scrutiny. Clear evidence for quantum criticality, particularly in the transport properties, has proved elusive because the important low-temperature region is masked by the onset of superconductivity. We present measurements of the low-temperature in-plane resistivity of several highly doped La2-xSrxCuO4 single crystals in which the superconductivity had been stripped away by using high magnetic fields. In contrast to other quantum critical systems, the resistivity varies linearly with temperature over a wide doping range with a gradient that scales monotonically with the superconducting transition temperature. It is maximal at a critical doping level (pc) approximately 0.19 at which superconductivity is most robust. Moreover, its value at pc corresponds to the onset of quasi-particle incoherence along specific momentum directions, implying that the interaction that first promotes high-temperature superconductivity may ultimately destroy the very quasi-particle states involved in the superconducting pairing.

18.
J Hosp Infect ; 66(4): 352-9, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17655976

ABSTRACT

Hospital cleaning currently has a high media profile. The effectiveness of an existing ward-cleaning regimen was assessed at selected sites over a 14 day period and shown to be highly variable. The cleaning regimen was subsequently modified in two stages, both changes involving a rinse stage and substituting cloths with disposable paper towels. One modification continued using the existing detergent; the other replaced detergent with a quaternary ammonium sanitiser. Both modifications yielded significantly lower and more consistent bacterial counts. Assessment of residual organic soil using adenosine triphosphate (ATP) detection demonstrated that failure rates (measurements exceeding benchmark clean value of 500 relative light units (RLU)) fell from 86-100% after existing cleaning methods, to 0-14% after modified cleaning. Maximum ATP readings fell from 163,870 to 2289 RLU. Incorporating a quaternary ammonium sanitiser into the cleaning regimen produced a further slight, but not significant, improvement in cleaning efficacy. These findings suggest that simple improvements can be made to existing cleaning regimens to increase their efficacy.


Subject(s)
Cross Infection/prevention & control , Disinfection/methods , Housekeeping, Hospital/methods , Infection Control/methods , Colony Count, Microbial/methods , Disinfection/standards , Environmental Monitoring , Equipment Contamination , Humans , Staphylococcus aureus/drug effects , Staphylococcus aureus/isolation & purification , Wales
19.
J Hosp Infect ; 65(1): 35-41, 2007 Jan.
Article in English | MEDLINE | ID: mdl-17140698

ABSTRACT

Although the association between environmental surfaces contaminated with meticillin-resistant Staphylococcus aureus (MRSA) and hospital infection rates is not fully understood, monitoring programmes can provide an objective starting point for the development and assessment of infection control strategies incorporating improved cleaning. There is, however, no universally accepted method for the recovery of MRSA from environmental surfaces, and the aim of this study was to evaluate a selection of currently available methods. Using five clinical isolates of MRSA and seven protocols, known numbers of bacteria were inoculated on to a stainless steel surface and either recovered immediately (without drying or adsorption) or recovered after 30min (with drying at room temperature and adsorption of cells to the surface). Surfaces were either swabbed or sampled directly by contact methods, and four nutritive media (blood, tryptone soya, oxacillin and meticillin-resistant agars) were tested. Relative sampling efficiencies were determined and the sensitivity of each method per 100cm(2) was calculated. Wide variation in the ability to recover MRSA was found between the different protocols. In the recovery of dried (adsorbed) cells, direct contact methods demonstrated higher sampling efficiency than swabs. The sensitivity of all methods was lower in recovering adsorbed cells from surfaces than unadsorbed cells. Sampling methods consistently proved to be more important than the choice of medium. Dipslides coated with selective agar are recommended for recovering MRSA from flat environmental surfaces.


Subject(s)
Environmental Monitoring/methods , Equipment Contamination , Fomites/microbiology , Infection Control/methods , Staphylococcus aureus/isolation & purification , Bacteriological Techniques , Cross Infection/microbiology , Cross Infection/prevention & control , Decontamination , Humans , Methicillin Resistance , Sensitivity and Specificity , Staphylococcus aureus/drug effects
20.
Clin Radiol ; 60(8): 905-13, 2005 Aug.
Article in English | MEDLINE | ID: mdl-16039926

ABSTRACT

AIM: The aim of this study was to correlate findings of perfusion magnetic resonance imaging (MRI) and perfusion scintigraphy in cases where there was a suspicion of abnormal pulmonary vasculature, and to evaluate the usefulness of MRI in the detection of perfusion deficits of the lung. METHODS: In all, 17 patients with suspected abnormality of the pulmonary vasculature underwent dynamic contrast-enhanced MRI. T1-weighted 3D fast-field echo pulse sequences were obtained (TR/TE 3.3/1.58 ms; flip angle 30 degrees; slice thickness 12 to 15 mm). The dynamic study was acquired in the coronal plane following administration of 0.1 mmol/kg gadopentetate dimeglumine. A total of 8 to 10 sections repeated 20 to 25 times at intervals of 1s were performed. Perfusion lung scintigraphy was carried out a maximum of 48 h before the MR examination in all cases. Two radiologists, who were blinded to the clinical data and results of other imaging methods, reviewed all coronal sections. MR perfusion images were independently assessed in terms of segmental or lobar perfusion defects in the 85 lobes of the 17 individuals, and the findings were compared with the results of scintigraphy. RESULTS: Of the 17 patients, 8 were found to have pulmonary emboli, 2 chronic obstructive pulmonary disease with emphysema, 2 bullous emphysema, 2 Takayasu arteritis and 1 had a hypoplastic pulmonary artery. Pulmonary perfusion was completely normal in 2 cases. In 35 lobes, perfusion defects were detected using both methods, in 4 with MR alone and in 9 only with scintigraphy. There was good agreement between MRI and scintigraphy findings (kappa=0.695). CONCLUSION: Pulmonary perfusion MRI is a new alternative to scintigraphy in the evaluation of pulmonary perfusion for various lung disorders. In addition, this technique allows measurement and quantification of pulmonary perfusion abnormalities.


Subject(s)
Image Processing, Computer-Assisted , Imaging, Three-Dimensional , Lung Diseases/physiopathology , Lung/physiopathology , Magnetic Resonance Angiography , Adult , Aged , Contrast Media/administration & dosage , Feasibility Studies , Gadolinium DTPA/administration & dosage , Humans , Lung/blood supply , Lung/diagnostic imaging , Lung Diseases/diagnostic imaging , Middle Aged , Pulmonary Artery/abnormalities , Pulmonary Artery/diagnostic imaging , Pulmonary Disease, Chronic Obstructive/diagnosis , Pulmonary Disease, Chronic Obstructive/physiopathology , Pulmonary Embolism/diagnosis , Pulmonary Emphysema/diagnosis , Pulmonary Emphysema/physiopathology , Radiography , Radionuclide Imaging , Sensitivity and Specificity , Takayasu Arteritis/diagnosis , Takayasu Arteritis/physiopathology , Technetium Tc 99m Aggregated Albumin
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