Biofouling causes performance loss in spiral wound nanofiltration (NF) and reverse osmosis (RO) membrane operation for process and drinking water production. The development of biofilm formation, ...structure and detachment was studied in-situ, non-destructively with Optical Coherence Tomography (OCT) in direct relation with the hydraulic biofilm resistance and membrane performance parameters: transmembrane pressure drop (TMP) and feed-channel pressure drop (FCP). The objective was to evaluate the suitability of OCT for biofouling studies, applying a membrane biofouling test cell operated at constant crossflow velocity (0.1 m s−1) and permeate flux (20 L m−2h−1).
In time, the biofilm thickness on the membrane increased continuously causing a decline in membrane performance. Local biofilm detachment was observed at the biofilm–membrane interface.
A mature biofilm was subjected to permeate flux variation (20 to 60 to 20 L m−2h−1). An increase in permeate flux caused a decrease in biofilm thickness and an increase in biofilm resistance, indicating biofilm compaction. Restoring the original permeate flux did not completely restore the original biofilm parameters: After elevated flux operation the biofilm thickness was reduced to 75% and the hydraulic resistance increased to 116% of the original values. Therefore, after a temporarily permeate flux increase the impact of the biofilm on membrane performance was stronger. OCT imaging of the biofilm with increased permeate flux revealed that the biofilm became compacted, lost internal voids, and became more dense. Therefore, membrane performance losses were not only related to biofilm thickness but also to the internal biofilm structure, e.g. caused by changes in pressure.
Optical Coherence Tomography proved to be a suitable tool for quantitative in-situ biofilm thickness and morphology studies which can be carried out non-destructively and in real-time in transparent membrane biofouling monitors.
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•In-situ imaging of biofilm thickness and structure.•Flux decline related to biofilm thickness and biofilm compaction.•Biofilm compaction caused by temporary permeate flux increase.•Reduced membrane performance by biofilm compaction after high flux operation.•Highest hydraulic resistance may be caused by the thinnest biofilm.
Canagliflozin, a potent, selective sodium glucose co‐transporter 2 inhibitor in development for treatment of type 2 diabetes, lowers plasma glucose (PG) by lowering the renal threshold for glucose ...(RTG) and increasing urinary glucose excretion (UGE). An ascending single oral‐dose phase 1 study investigated safety, tolerability and pharmacodynamics of canagliflozin in healthy men (N = 63) randomized to receive canagliflozin (n = 48) or placebo (n = 15). Canagliflozin (10, 30, 100, 200, 400, 600 or 800 mg q.d. or 400 mg b.i.d.) was administered to eight cohorts (six subjects/cohort: canagliflozin; two subjects/cohort: placebo). Dose dependently, canagliflozin decreased calculated 24‐h mean RTG with maximal reduction to approximately 60 mg/dl, and increased mean 24‐h UGE. At doses >200 mg administered before breakfast, canagliflozin reduced postprandial PG and serum insulin excursions at that meal. Canagliflozin was generally well tolerated; most adverse events were mild and no hypoglycaemia was reported. These results support further study of canagliflozin.
Aim
To examine the association of in‐hospital diabetes regimen intensification with subsequent 30‐day risk for unplanned readmission/emergency department admission.
Methods
We retrospectively studied ...1949 adults with Type 2 diabetes receiving primary care within an academic health network admitted to the hospital between January 2007 and December 2009. Glucose therapy intensification was defined as new start of insulin or oral hypoglycaemic agents, or addition of prandial insulin or insulin mixtures. The association of glucose therapy intensification with subsequent 30‐day risk for unplanned readmission/emergency department admission was examined, with focus on medicine service patients with poorly controlled glycaemia (baseline HbA1c ≥ 64 mmol/mol).
Results
One in six patients (324/1949, 17%) had early readmission/emergency department admission. Compared with patients without early readmission, readmitted patients were more often male (58 vs. 52%, P = 0.03), had higher Charlson co‐morbidity score mean (sd) 3.0 (2.0) vs. 2.8 (1.8), P = 0.02, longer length of stay 5 (4.4) vs. 3.9 (3.3) days, P < 0.01 and were more often discharged home with nursing services (38 vs. 32%, P = 0.03). Overall, glucose therapy intensification was not associated with early hospital readmission/emergency department admission (odds ratio 0.94, 95% CI 0.64–1.37, P = 0.74). However, among medicine service patients with baseline HbA1c ≥ 64 mmol/mol (8%), glucose therapy intensification was associated with a significantly decreased early readmission risk (adjusted odds ratio 0.33, 95% CI 0.12–0.88, P = 0.03) and lower post‐discharge HbA1c {mean decrease (sd): 20 (26) mmol/mol 1.8 (2.4)% vs. 7 (15) mmol/mol 0.6 (1.4)%, P < 0.01}.
Conclusions
Diabetes medical regimen intensification during hospitalization was not associated with early readmission. Among patients with elevated HbA1c, glucose therapy intensification was associated with a decreased 30‐day readmission/emergency department admission risk and lower outpatient HbA1c levels. Our findings support the safety and durable impact of diabetes regimen optimization during hospital admission.
We assessed the impact of medical comorbidities, depression, and treatment intensity on quality of life in a large primary care cohort of patients with type 2 diabetes.
We used the Health Utilities ...Index-III, an instrument that measures health-related quality of life based on community preferences in units of health utility (scaled from 0=death to 1.0=perfect health), in 909 primary care patients with type 2 diabetes. Demographic and clinical correlates of health-related quality of life were assessed.
The median health utility score for this population was 0.70 (interquartile range 0.39-0.88). In univariate analyses, older age, female sex, low socioeconomic status, cardiovascular disease, microvascular complications, congestive heart failure, peripheral vascular disease, chronic lung disease, depression, insulin use and number of medications correlated with decreased quality of life, while obesity, hypertension and hypercholesterolaemia did not. In multiple regression analyses, microvascular complications, heart failure and depression were most strongly related to decreased health-related quality of life, independently of duration of diabetes; in these models, diabetes patients with depression had a utility of 0.59, while patients without symptomatic comorbidities did not have a significantly reduced quality of life. Treatment intensity remained a significant negative correlate of quality of life in multivariable models.
Patients with type 2 diabetes have a substantially decreased quality of life in association with symptomatic complications. The data suggest that treatment of depression and prevention of complications have the greatest potential to improve health-related quality of life in type 2 diabetes.
Mechanically induced reactive synthesis of TiN via magnetically controlled ball milling of titanium under nitrogen gas was investigated using X-ray diffraction, advanced electron microscopy and Raman ...spectroscopy. Ball milling of titanium powder with nitrogen gas was performed in Uni-Ball-Mill, with external temperature of the vial and initial pressures of the nitrogen gas monitored, while the milled samples were taken out periodically, both before and after detection of an exothermic ignition point. Before ignition, nitrogen-enriched Ti, small proportions of TiN and very minor amounts of Ti
2
N are formed, in addition to the heavily deformed Ti. Raman spectroscopy revealed the pre-ignition products to include off-stoichiometric nitrides (TiN
x
) and oxynitride skin (TiO
x
N
y
). The formation of the new TiN and Ti
2
N products before ignition was attributed to the diffusion of highly polarized active N atoms into the mechanically activated clean surfaces of Ti, followed by local reaction. This local reaction is likely promoted by numerous cycles of induced local temperature rise and rapid quenching, large surface area and accumulation of deformation defects. After the exothermic ignition, there was rapid nucleation of new TiN crystals, and simultaneous growth of the pre-existing TiN and the newly formed TiN crystals. This understanding explains the reaction pathways leading to the formation of small proportions of TiN and very minor amounts of Ti
2
N before ignition and the thin-plated TiN after ignition.
Aims To examine prospectively the association of depression symptoms with subsequent self‐care and medication adherence in patients with Type 2 diabetes mellitus.
Methods Two hundred and eight ...primary care patients with Type 2 diabetes completed the Harvard Department of Psychiatry/National Depression Screening Day Scale (HANDS) and the Summary of Diabetes Self‐Care Activities (SDSCA) at baseline and at follow‐up, an average of 9 months later. They also self‐reported medication adherence at baseline and at a follow‐up.
Results Baseline HANDS scores ranged from 0 to 27, with a mean score of 5.15 ± 4.99. In separate linear regression models that adjusted for baseline self‐care, patients with higher levels of depressive symptoms at baseline reported significantly lower adherence to general diet recommendations and specific recommendations for consumption of fruits and vegetables and spacing of carbohydrates; less exercise; and poorer foot care at follow‐up (β ranging from −0.12 to −0.23; P < 0.05). Similarly, each one‐point increase in baseline HANDS score was associated with a 1.08‐fold increase in the odds of non‐adherence to prescribed medication at follow‐up (95% confidence interval 1.001, 1.158, P = 0.047). Increases in depression scores over time also predicted poorer adherence to aspects of diet and exercise.
Conclusions Depressive symptoms predict subsequent non‐adherence to important aspects of self‐care in patients with Type 2 diabetes, even after controlling for baseline self‐care. Although the relationship between symptoms of depression and poorer diabetes self‐care is consistent, it is not large, and interventions may need to address depression and self‐care skills simultaneously in order to maximize effects on diabetes outcomes.
An understanding of groundwater flow near drinking water extraction wells is crucial when it comes to avoiding well clogging and pollution. A promising new approach to groundwater flow monitoring is ...the deployment of a network of optical fibers with fiber Bragg grating (FBG) sensors. In preparation for a field experiment, a laboratory scale aquifer was constructed to investigate the feasibility of FBG sensors for this application. Multiparameter FBG sensors were able to detect changes in temperature, pressure, and fiber shape with sensitivities influenced by the packaging. The first results showed that, in a simulated environment with a flow velocity of 2.9 m/d, FBG strain effects were more pronounced than initially expected. FBG sensors of a pressure-induced strain implemented in a spatial array could form a multiplexed sensor for the groundwater flow direction and magnitude. Within the scope of this research, key technical specifications of FBG interrogators for groundwater flow sensing were also identified.
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•Two distinguishable structures of WELs were revealed in ex-service damaged rails.•Martensitic WELs associated with a deformed pearlite structure are induced by RCF.•Austenitic WELs ...are thermally or thermomechanically induced.•WELs are related to the occurrence of squats.
Squats are recognized as an important rail track issue related to rolling contact fatigue, and represent a serious problem affecting significant parts of railway networks across the world. The mechanisms of squat initiation and propagation are still a matter of controversy. Research efforts have included understanding of possible relationships between the narrow and brittle white etching layers (WELs) observed on rail surfaces and squat formation in rails. In the present investigation, structural and microstructural features of ex-service damaged rails containing squats and WELs were investigated in order to determine the formation mechanism of white etching layers (WELs) on the rail surface. Synchrotron XRD analysis of rail surfaces, combined with microstructural and microhardness investigations, revealed two distinguishable types of WELs; one characterised by the presence of fine martensite and the other characterised by the presence both of retained austenite and martensite. WELs containing martensite were found to be associated with a deformed subsurface pearlite structure and it was concluded that this type of WEL is induced by severe plastic deformation at wheel-rail interface. In contrast, the WELs containing both of significant amounts of retained austenite and martensite, were associated with the presence of undeformed pearlite in the underlying structure and it was concluded that this type of WEL is either thermally or thermomechanically induced. Synchrotron XRD results obtained from regions of squat defects themselves are consistent to that of WELs containing austenite and martensite in regions near the squats, which indicates a relationship between WELs and squat initiations. Occurrences of cracks extending from WELs down into the rail in squat regions were confirmed by microstructural observations, which is consistent with the premise that cracks in squats originate from an extension of cracks in WELs.
A comprehensive investigation of the Sydney Trains railway network has been carried out to control and minimize rail degradation, especially squat defects. Squat occurrence was analysed with respect ...to the parameters of traffic operation and track geometry. Detailed metallurgical examination of the ex-service rails revealed a possible connection between brittle White Etching Layers (WELs) and the occurrence of squats in the running band of the rail. Initiation of squats was found to be associated with the progression of surface cracks in the WELs. Furthermore, two distinguishable types of WELs were found, based on different track operational conditions. These are described as Thermally Produced WEL (TP-WEL) which was found in heavy braking regions, and Severe Deformation WEL (SD-WEL) which was found in track regions under steady traffic speeds. In addition to the explanations based on thermal phase transformation and severe plastic deformation, the arcing phenomenon associated with electrical leakage at the wheel/rail interface was considered an alternative formation mechanism of WELs observed on rails. A revised rail grinding strategy was proposed by considering the formation of WELs and addressing it through more regular, relatively shallow grinding to effectively control squat defects.
•Squat occurrence was analysed with respect to traffic operation and track geometry conditions.•Metallurgical examination of the ex-service rails revealed a connection between WELs and the occurrence of squats.•WELs form due to (1) thermal phase transformation; (2) severe plastic deformation; (3) leaking current between wheel/rail.•It was proposed to effectively control squats by considering WELs and addressing it through more regular, shallow grinding.
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