Search

Self-imaging of ultrashort-pulsed nondiffracting needle beams, i.e., fringe-free Bessel beams, is analyzed. In contrast to the classical diffractive Talbot effect, pulse revivals with minimum spectral and temporal distortion are obtained. Robustness is further enhanced by self-reconstruction. The high-fidelity pulse transfer enables spatial and temporal multiplexing in free space without the need for a nonlinear medium, even at pulse durations down to the few-cycle range.

Aim: To determine the incidence of hospitalisations and risk factors for vascular complications experienced during early adulthood in patients with childhood onset type 1 diabetes., Methods: A population-based childhood onset type 1 diabetes cohort was identified from a statewide register (1992-2012). Data linkage was used to identify a matched comparison cohort. Hospital admissions data were extracted to follow up both cohorts into early adulthood (1975-2012)., Results: The type 1 diabetes cohort (n=1316) had a mean age of diagnosis of 9.5years, 49.5% were women and mean age at the end of follow-up was 26.3years (range 18-38). Within the type 1 diabetes cohort 32 (2.4%) were hospitalised with a vascular complication during early adulthood. Poor glycaemic control during paediatric management was associated with a significant increase in risk for ophthalmic complication with 19.4% (n=12/62) of those with a mean HbA1c >12% (108mmol/mol) diagnosed compared to 0.72% (n=5/696) of those with mean HbA1c <9% (75mmol/mol), adjusted hazard ratio 8.4 (95% CI 2.0, 34.7)., Conclusion: Severe vascular complications requiring hospital admission continue to be observed during early adulthood. Both women and those with poor glycaemic control are at increased risk of requiring a hospital admission for these complications during early adulthood., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Embryo morphogenesis relies on highly coordinated movements of different tissues. However, remarkably little is known about how tissues coordinate their movements to shape the embryo. In zebrafish embryogenesis, coordinated tissue movements first become apparent during "doming," when the blastoderm begins to spread over the yolk sac, a process involving coordinated epithelial surface cell layer expansion and mesenchymal deep cell intercalations. Here, we find that active surface cell expansion represents the key process coordinating tissue movements during doming. By using a combination of theory and experiments, we show that epithelial surface cells not only trigger blastoderm expansion by reducing tissue surface tension, but also drive blastoderm thinning by inducing tissue contraction through radial deep cell intercalations. Thus, coordinated tissue expansion and thinning during doming relies on surface cells simultaneously controlling tissue surface tension and radial tissue contraction., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Hypoglycemia remains a risk for closed loop insulin delivery particularly following exercise or if the glucose sensor is inaccurate. The aim of this study was to test whether an algorithm that includes a limit to insulin delivery is effective at protecting against hypoglycemia under those circumstances., Methods: An observational study on 8 participants with type 1 diabetes was conducted, where a hybrid closed loop system (HCL) (Medtronic™ 670G) was challenged with hypoglycemic stimuli: exercise and an overreading glucose sensor., Results: There was no overnight or exercise-induced hypoglycemia during HCL insulin delivery. All daytime hypoglycemia was attributable to postmeal bolused insulin in those participants with a more aggressive carbohydrate factor., Conclusion: HCL systems rely on accurate carbohydrate ratios and carbohydrate counting to avoid hypoglycemia. The algorithm that was tested against moderate exercise and an overreading glucose sensor performed well in terms of hypoglycemia avoidance. Algorithm refinement continues in preparation for long-term outpatient trials.

The development of first cellular structures played an important role in the early evolution of life. Early evolution of life probably took place on a molecular level in a reactive environment. The iron-sulfur theory postulates the formation of cell-like structures on catalytic surfaces. Experiments show that H 2 S together with FeS and other metallic centers drive auto-catalytic surface reactions, in which organic molecules such as pyruvic and amino acids occur. It is questionable which mechanisms are needed to form cell-like structures under these conditions. To address this question, we implemented a model system featuring the fundamentals of molecular dynamics: heat, attraction, repulsion and formation of covalent bonds. Our basic model exhibits a series of essential processes: self-organization of lipid micelles and bilayers, formation of fluid filled cavities, flux of molecules along membranes, transport of energized groups towards sinks and whole colonies of cell-like structures on a larger scale. The results demonstrate that only a few features are sufficient for discovering hitherto non described phenomena of self-assembly and dynamics of cell-like structures as candidates for early evolving proto-cells. Significance statement The quest for a possible origin of life continues to be one of the most fascinating problems in biology. In one theoretical scenario, early life originated from a solution of reactive chemicals in the ancient deep sea, similar to conditions as to be found in thermal vents. Experiments have shown that a variety of organic molecules, the building blocks of life, form under these conditions. Based on such experiments, the iron-sulfur theory postulates the growth of cell-like structures at certain catalytic surfaces. For an explanation and proof of such a process we have developed a computer model simulating molecular assembly of lipid bilayers and formation of semi-cell cavities. The results demonstrate the possibility of cell-like self-organization under appropriate physico-chemical conditions., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Background: We compared glycemia, treatment satisfaction, sleep quality, and cognition using a nighttime Android-based hybrid closed-loop system (Android-HCLS) with sensor-augmented pump with low-glucose suspend function (SAP-LGS) in people with type 1 diabetes., Materials and Methods: An open-label, prospective, randomized crossover study of 16 adults (mean [SD] age 42.1 [9.6] years) and 12 adolescents (15.2 [1.6] years) was conducted. All participants completed four consecutive nights at home with Android-HCLS (proportional integral derivative with insulin feedback algorithm; Medtronic) and SAP-LGS., Primary Outcome: percent continuous glucose monitoring (CGM) time (00:00-08:00 h) within target range (72-144 mg/dL). Secondary endpoints: percent CGM time above target (>144 mg/dL); below target (<72 mg/dL); glycemic variability (SD); symptomatic hypoglycemia; adult treatment satisfaction; sleep quality; and cognitive function., Results: The primary outcome for all participants was not statistically different between Android-HCLS and SAP-LGS (mean [SD] 59.4 [17.9]% vs. 53.1 [18]%; p = 0.14). Adults had greater percent time within target range (57.7 [18.6]% vs. 44.5 [14.5]%; p < 0.006); less time above target (42.0 [18.7]% vs. 52.6 [16.5]%; p = 0.034); lower glycemic variability (35 [10.7] mg/dL vs. 46 [10.7] mg/dL; p = 0.003); and less (median [IQR]) time below target (0.0 [0.0-0.4]% vs. 0.80 [0.0-3.9]%; p = 0.025). In adolescents, time below target was lower with Android-HCLS vs. SAP-LGS (0.0 [0.0-0.0]% vs. 1.8 [0.1-7.9]%; p = 0.011). Nocturnal symptomatic hypoglycemia was less (1 vs. 10; p = 0.007) in adolescents, but not adults (5 vs. 13; p = 0.059). In adults, treatment satisfaction increased by 10 points (p < 0.02). Sleep quality and cognition did not differ., Conclusions: Android-HCLS in both adults and adolescents reduced nocturnal hypoglycemia and, in adults, improved overnight time in target range and treatment satisfaction compared with SAP-LGS.

Background: We aimed to assess insulin sensitivity and other metabolic features of dippers and non-dippers among overweight middle-aged men., Methods: We studied 73 men (45.8 ± 5.3 years) who were overweight but normotensive. Participants were separated into dippers and non-dippers based on the magnitude of the nocturnal decline of blood pressure, with dippers experiencing an overnight decline ≥10% as per standard definition. Our study included 51 dippers and 22 non-dippers. All participants underwent 24-hour ambulatory blood pressure monitoring. Insulin sensitivity was assessed by the Matsuda method from an oral glucose tolerance test; other assessments included carotid artery intima-media thickness (CIMT), body composition derived from dual-energy X-ray absorptiometry, lipid profiles, and a physical activity questionnaire., Results: Non-dippers had lower daytime systolic (-5.0mmHg; p=0.022) and diastolic (-3.3mmHg; p=0.035) blood pressure than dippers. Conversely, during sleep, non-dippers had higher systolic (+6.5mmHg; p=0.003) and diastolic (+5.6mmHg; p=0.001) blood pressure. In continuous associations, increasing CIMT was associated with decreasing systolic (p=0.012) and diastolic (p=0.042) dipping. Thus, non-dippers had CIMT that was 9% greater than that of dippers (749 vs 820μm; p=0.036). Importantly, there was no association between non-dipping status or the magnitude of the nocturnal dip with insulin sensitivity., Conclusions: Non-dippers had lower blood pressure in the daytime, but higher blood pressure in the night time compared to dippers. Non-dippers had increased CIMT, which suggests that normotensive men with a non-dipping ambulatory blood pressure profile may be at increased cardiovascular risk. However, it appears that the non-dipping profile is unrelated to dysfunction of glucose homeostasis in overweight normotensive men., (Copyright © 2016 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.)

Background: Sensor-augmented pump therapy (SAPT) with algorithms to predict impending low blood glucose and suspend insulin delivery has the potential to reduce hypoglycemia exposure. The aim of this study was to determine whether predictive low glucose management (PLGM) system is effective in preventing insulin-induced hypoglycemia in controlled experiments., Methods: Two protocols were used to induce hypoglycemia in an in-clinic environment. (A) Insulin bolus: Insulin was administered as a manual bolus through the pump. (B) Increased basal insulin: Hypoglycemia was induced by increasing basal rates overnight to 180%. For both protocols, participants were randomized and studied on 2 separate days; a control day with SAPT alone and an intervention day with SAPT and PLGM activated. The predictive algorithm was programmed to suspend basal insulin infusion when sensor glucose was predicted to be <80 mg/dL in 30 min. The primary outcome was the requirement for hypoglycemia treatment (symptomatic hypoglycemia or plasma glucose <50 mg/dL) and was compared in both control and intervention arms., Results: With insulin bolus, 24/28 participants required hypoglycemia treatment with SAPT alone compared to 5/28 participants when PLGM was activated (P ≤ 0.001). With increased basal rates, all the eight SAPT-alone participants required treatment for hypoglycemia compared to only one with SAPT and PLGM. There was no post pump-suspend hyperglycemia with insulin bolus (P = 0.4) or increased basal rates (P = 0.69) in participants with 2-h pump suspension on intervention days., Conclusions: SAPT with PLGM reduced the requirement for hypoglycemia treatment following insulin-induced hypoglycemia in an in-clinic setting.

Aims: This study reports continuous glucose monitoring (CGM) adherence patterns and contributing factors in patients who were part of a 6-month clinical trial using sensor augmented pump therapy with low glucose insulin suspension., Methods: CGM data from 38 patients using sensor augmented pump therapy for 6 months were analyzed. CGM adherence was defined by having a working sensor available and determined by the time it was switched on as a proportion of available time for the 6 month study period with allowance for practical CGM use. Age, gender, HbA1c, duration of diagnosis, capillary blood glucose testing frequency, sensor accuracy, and insulin pump alarm frequency were characterized and examined for an association with CGM adherence., Results: Overall CGM adherence was 75% (range: 35% to 96%), CGM adherence was demonstrated to fall after 9 to 11 weeks before reaching a steady rate. CGM adherence patterns showed substantial variation. Mean adherence differed (P < .01) between age groups 72% (<12 years), 69% (12-18 years), and 88% (≥18 years). Sensor accuracy predicted adherence, where every 1% decline in mean absolute difference in a given week was associated with a 0.5% decline in sensor adherence (P < .01). Gender, HbA1c, duration of diagnosis, capillary blood glucose testing frequency, and insulin pump alarm frequency were not associated with CGM adherence., Conclusions: CGM adherence and patterns of use are individualized. However, a predictable fall in adherence at 9 to 11 weeks may present an opportunity for timed interventions to increase CGM use. Adolescent age and sensor accuracy predict CGM adherence., Competing Interests: The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: MD was supported by the Juvenile Diabetes Research Foundation mentored fellowship and received honoraria for scientific lectures (Medtronic) and travel reimbursement from Novo-Nordisk and the Juvenile Diabetes Research Foundation mentored fellowship. TL was supported by the Juvenile Diabetes Research Foundation postdoctoral fellowship and received travel support from Medtronic. TJ received honoraria for scientific lectures and travel reimbursement from Medtronic, Sanofi-aventis, Eli Lilly, and Novo-Nordisk., (© 2016 Diabetes Technology Society.)

A 2.051-µm laser source delivering picosecond pulses with energies as high as 34 mJ at a 1 kHz repetition rate is reported. The main amplifier system is based on Ho:YLF and consists of a regenerative amplifier (RA) and a single-pass booster amplifier running at room temperature. The continuous-wave pumped, high-gain RA produces pulse trains with up to 10-mJ energy when operating in a stable periodic doubling regime. The recorded complete RA bifurcation diagram agrees well with our numerical simulations. At the highest pulse energy after the booster amplifier the pulse-to-pulse fluctuations are as low as 0.9% rms. Pulse compression is performed up to the 10-mJ level resulting in a duration of 37 ps.

Hyperinsulinaemic hypoglycaemia (HH) is characterised by inappropriate insulin secretion and is the most common cause for persistent neonatal hypoglycaemia. The only treatment available for medically unresponsive hypoglycaemia is a near-total pancreatectomy. A neonate with severe HH, due to a homozygous ABCC8 mutation, was not responsive to treatment with maximal doses of diazoxide and subcutaneous daily octreotide, and underwent a near-total pancreatectomy; however, hypoglycaemia persisted. Introduction of sirolimus, an mTOR (mammalian target of rapamycin) inhibitor, obviated the requirement for glucose infusion. Euglycaemia was achieved with no significant adverse events from the drug. Sirolimus therapy was ceased at 13 months of age. No episodes of persistent hypoglycaemia were observed after cessation of sirolimus. This report demonstrates the successful use of sirolimus for persistent hypoglycaemia in the critically ill infant post pancreatectomy. Sirolimus could be considered in patients with severe HH not responsive to conventional medical and surgical therapy. However, the long-term efficacy and safety with this immunosuppressive drug in very young patients are not assured.

We report a high-gain, cw-pumped regenerative amplifier which is based on Ho-doped crystals and seeded by a versatile broadband source emitting between 2050 and 2100 nm. The regenerative amplifier is implemented in a chirped-pulse amplification system operating at room temperature. Using Ho:YLF as gain medium, 1.1 mJ pulses with a 50 ps pulse duration and a 10 kHz repetition rate are generated at 2050 and 2060 nm, corresponding to an average power of 11 W. Using the same seed source, a 10 kHz Ho:YAG regenerative amplifier at 2090 nm is studied in the same configuration. In all cases the regenerative amplifier parameters are chosen to operate in a tunable single-energy regime without instabilities.

The total and semi-synthesis of 13 new macrolactones derived from thuggacin, which is a secondary metabolite from the myxobacterium Sorangium cellulosum, are reported. The thuggacins have attracted much attention due to their strong antibacterial activity, particularly towards Mycobacterium tuberculosis. This study focuses on 1) thuggacin derivatives that cannot equilibrate by transacylation between the three natural thuggacins A-C, 2) the roles of the thiazole ring, and 3) the hexyl side chain at C2. Semi-synthetic O-methylation at C17 suppressed the transacylations without a substantial loss of antibacterial activity. Exchanging the C17-C25 side chain for simplified hydrophobic chains led to complete loss of antibacterial activity. Exchange of the thiazole by an oxazole ring or removal of the hexyl side chain at C2 had no substantial effect on the biological properties., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Wave fields, which are described mathematically by higher order Bessel functions, carry an orbital angular momentum and thus represent particular types of optical vortex beams with helical wavefronts. For the generation of such vortex beams, one may use, for instance, diffractive spiral axicons. Diffraction, however, leads invariably to strong dispersion, which is detrimental for ultrashort pulses since it leads to severe pulse broadening. This pulse broadening can be minimized or reduced completely (at least, in a specific plane of propagation) if the pulses propagate additionally through a medium with normal refractive dispersion. The refractive-diffractive generation of ultrashort vortex pulses was demonstrated earlier for a pulse duration of approximately 8 fs [Opt. Lett.37, 3804 (2012)10.1364/OL.37.003804OPLEDP0146-9592]. Here, we present an analytical description of the generation and propagation of these vortex beams and of the refractive-diffractive compensation of the dispersion.

We aimed to assess whether birth order affects metabolism and body composition in overweight middle-aged men. We studied 50 men aged 45.6 ± 5.5 years, who were overweight (BMI 27.5 ± 1.7 kg/m(2)) but otherwise healthy in Auckland, New Zealand. These included 26 first-borns and 24 second-borns. Insulin sensitivity was assessed by the Matsuda method from an oral glucose tolerance test. Other assessments included DXA-derived body composition, lipid profiles, 24-hour ambulatory blood pressure, and carotid intima-media thickness. First-born men were 6.9 kg heavier (p = 0.013) and had greater BMI (29.1 vs 27.5 kg/m(2); p = 0.004) than second-borns. Insulin sensitivity in first-born men was 33% lower than in second-borns (4.38 vs 6.51; p = 0.014), despite adjustment for fat mass. There were no significant differences in ambulatory blood pressure, lipid profile or carotid intima-media thickness between first- and second-borns. Thus, first-born adults may be at a greater risk of metabolic and cardiovascular diseases.

We assessed whether increasing body mass index (BMI) affects health-related quality of life in a group of 38 overweight (BMI 25-30 kg/m(2)) middle-aged (45.9 ± 5.4 years) men, recruited in Auckland (New Zealand). Health-related quality of life was assessed with SF-36v2 at 0, 12, and 30 weeks. Increasing BMI was associated with a progressive reduction in physical component summary score (p = 0.008), as well as lower general health (p = 0.036), physical functioning (p = 0.024), and bodily pain (p = 0.030) scores. Stratified analyses confirmed these findings: participants who were more overweight (n = 19; BMI 27.5-30 kg/m(2)) had poorer physical component summary (p = 0.005), physical functioning (p = 0.040), bodily pain (p = 0.044), and general health (p = 0.073) scores than the less overweight (n = 19; BMI 25-27.5 kg/m(2)). Increasing BMI is associated with a progressive reduction in physical quality of life, even within a relatively narrow BMI range encompassing only overweight middle-aged men.

Background/aims: Donohue and Rabson-Mendenhall syndrome are rare autosomal recessive disorders caused by mutations in the insulin receptor gene, INSR. Phenotypic features include extreme insulin resistance, linear growth retardation, paucity of fat and muscle, and soft tissue overgrowth. The insulin receptor is also expressed in the kidney, where animal data suggest it plays a role in glomerular function and blood pressure (BP) regulation, yet such a role in the human kidney is untested. Patients with biallelic INSR mutations provide a rare opportunity to ascertain its role in man., Methods: Retrospective review of patients with INSR mutations. Data for BP, renal imaging, plasma creatinine and electrolyte levels, as well as urine protein, albumin and calcium excretion were sought from the treating clinicians., Results: From 33 patients with INSR mutations, data were available for 17 patients. Plasma creatinine was low (mean ± SD: 25 ± 9 μmol/l) and mean plasma electrolyte concentrations were within the normal range (n = 13). Systolic BP ranged between the 18th and 91st percentile for age, sex, height and weight (n = 9; mean ± SD: 49 ± 24). Twenty-four-hour urinary calcium data were available from 10 patients and revealed hypercalciuria in all (mean ± SD: 0.32 ± 0.17 mmol/kg/day; normal <0.1). Nephrocalcinosis was present in all patients (n = 17). Urinary albumin excretion (n = 7) ranged from 4.3-122.5 μg/min (mean ± SD: 32.4 ± 41.0 μg/min; normal <20)., Conclusions: INSR dysfunction is associated with hypercalciuria and nephrocalcinosis. No other consistent abnormality of renal function was noted. Normotension and stable glomerular function with only moderate proteinuria is in contrast to genetically modified mice who have elevated BP and progressive diabetic nephropathy., (© 2014 S. Karger AG, Basel.)

Phenolic compounds derived from the olive plant (Olea europaea L.), particularly hydroxytyrosol and oleuropein, have many beneficial effects in vitro. Olive leaves are the richest source of olive phenolic compounds, and olive leaf extract (OLE) is now a popular nutraceutical taken either as liquid or capsules. To quantify the bioavailability and metabolism of oleuropein and hydroxytyrosol when taken as OLE, nine volunteers (five males) aged 42.8 ± 7.4 years were randomized to receive either capsulated or liquid OLE as a single lower (51.1 mg oleuropein, 9.7 mg hydroxytyrosol) or higher (76.6 mg oleuropein, 14.5 mg hydroxytyrosol) dose, and then the opposite strength (but same formulation) a week later. Plasma and urine samples were collected at fixed intervals for 24 h post-ingestion. Phenolic content was analyzed by LC-ESI-MS/MS. Conjugated metabolites of hydroxytyrosol were the primary metabolites recovered in plasma and urine after OLE ingestion. Peak oleuropein concentrations in plasma were greater following ingestion of liquid than capsule preparations (0.47 versus 2.74 ng/mL; p = 0.004), but no such effect was observed for peak concentrations of conjugated (sulfated and glucuronidated) hydroxytyrosol (p = 0.94). However, the latter peak was reached earlier with liquid preparation (93 versus 64 min; p = 0.031). There was a gender effect on the bioavailability of phenolic compounds, with males displaying greater plasma area under the curve for conjugated hydroxytyrosol (11,600 versus 2550 ng/mL; p = 0.048). All conjugated hydroxytyrosol metabolites were recovered in the urine within 8 h. There was wide inter-individual variation. OLE effectively delivers oleuropein and hydroxytrosol metabolites to plasma in humans., (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Novel types of reflective spiral micro-electro-mechanical systems were used to generate few-cycle vortex pulses of variable topological charge from a Ti:sapphire laser oscillator. The phase profile of these components was controlled by varying the temperature. The temporal properties of the pulses were characterized with spatially resolved nonlinear autocorrelation. The beam structure resembles a slightly distorted Laguerre-Gaussian distribution. The different topological charges were indicated by detecting Poynting-vector maps with a programmable Shack-Hartmann sensor of enhanced angular sensitivity.

Background: Olive plant leaves (Olea europaea L.) have been used for centuries in folk medicine to treat diabetes, but there are very limited data examining the effects of olive polyphenols on glucose homeostasis in humans., Objective: To assess the effects of supplementation with olive leaf polyphenols (51.1 mg oleuropein, 9.7 mg hydroxytyrosol per day) on insulin action and cardiovascular risk factors in middle-aged overweight men., Design: Randomized, double-blinded, placebo-controlled, crossover trial in New Zealand. 46 participants (aged 46.4 ± 5.5 years and BMI 28.0 ± 2.0 kg/m(2)) were randomized to receive capsules with olive leaf extract (OLE) or placebo for 12 weeks, crossing over to other treatment after a 6-week washout. Primary outcome was insulin sensitivity (Matsuda method). Secondary outcomes included glucose and insulin profiles, cytokines, lipid profile, body composition, 24-hour ambulatory blood pressure, and carotid intima-media thickness., Results: Treatment evaluations were based on the intention-to-treat principle. All participants took >96% of prescribed capsules. OLE supplementation was associated with a 15% improvement in insulin sensitivity (p = 0.024) compared to placebo. There was also a 28% improvement in pancreatic β-cell responsiveness (p = 0.013). OLE supplementation also led to increased fasting interleukin-6 (p = 0.014), IGFBP-1 (p = 0.024), and IGFBP-2 (p = 0.015) concentrations. There were however, no effects on interleukin-8, TNF-α, ultra-sensitive CRP, lipid profile, ambulatory blood pressure, body composition, carotid intima-media thickness, or liver function., Conclusions: Supplementation with olive leaf polyphenols for 12 weeks significantly improved insulin sensitivity and pancreatic β-cell secretory capacity in overweight middle-aged men at risk of developing the metabolic syndrome.

Few-cycle high-contrast vortex beams with pulse durations around 8 fs were generated from a Ti:sapphire laser oscillator with a single diffractive-refractive component. Angular and temporal pulse properties were characterized with an advanced time-wavefront sensor. The temporal transfer indicates a fairly complete self-compensation.

A highly flexible Shack-Hartmann wavefront sensor for ultrashort pulse diagnostics is presented. The temporal system performance is studied in detail. Reflective operation is enabled by programming tilt-tolerant microaxicons into a liquid-crystal-on-silicon spatial light modulator. Nearly undistorted pulse transfer is obtained by generating nondiffracting needle beams as subbeams. Reproducible wavefront analysis and spatially resolved second-order autocorrelation are demonstrated at incident angles up to 50° and pulse durations down to 6 fs.

Aim: To examine the clinical impact of insulin-pump therapy for children with type 1 diabetes mellitus (T1DM) in a regional paediatric service, Auckland, New Zealand., Methods: Retrospective analysis of children with T1DM from the Starship paediatric diabetes database who started on insulin-pump therapy from 2002 to 2008 compared with the whole T1DM population and with an equal number of non-pump patients matched by age, sex, ethnicity and duration of diabetes., Results: From 621 subjects with 6680 clinic visits, 75 children were treated with insulin-pump therapy for more than 12 months. Transitioning to insulin-pump treatment was associated with an improvement in HbA1c compared with baseline (-0.3%/year, P < 0.001) for up to 3 years. In contrast, despite similar deprivation scores, non-pump controls showed a continuing trend to higher HbA1C values (+0.2%/year, P < 0.01). The risk of severe hypoglycaemia fell after pump start (from 27 (0-223) to 5 (0-0.91) events/100 patient years) with no change in non-pump controls; the rate of diabetic ketoacidosis remained low in both groups., Conclusions: In a pump-naïve regional paediatric population, insulin-pump therapy for T1DM was safe and effective, and associated with sustained improvements in HbA1c and lower risk of hypoglycaemia., (© 2011 The Authors. Journal of Paediatrics and Child Health © 2011 Paediatrics and Child Health Division (Royal Australasian College of Physicians).)

With conventional methods the sound velocity c in fluids can be determined using the back wall echo. This paper proposes a novel technique, in which the signals reflected by scattering particles suspended in a fluid are analysed instead. The basic idea is that the particles generate the strongest echo signal when being located in the sound field maximum. Therefore the position of the echo signal maximum is a measure for the propagation time to the sound field maximum. Provided that calibration data or sound field simulations for the ultrasonic transducer are available, this propagation time suffices to determine both sound velocity and the location of the sound field maximum. The feasibility of the new approach is demonstrated by different kinds of experiments: (i) Measurements of the sound velocity c in four fluids covering the wide range between 1116 and 2740m/s. The results show good agreement with values published elsewhere. (ii) Using the dependence of the sound velocity on temperature, it is possible to vary c over the comparatively small range between 1431 and 1555m/s with increments of less than 10m/s. The measured statistical variation of 1.4m/s corresponds to a relative uncertainty not worse than 0.1%. (iii) The focus position, i.e. the distance of the maximum of the sound field from the transducer, was varied by time-shifted superposition of the receive signals belonging to the different elements of an annular array. The results indicate that the novel method is even capable of measuring profiles of the sound velocity along the ultrasonic beam non-invasively., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Aims: We aimed to assess the effects of psyllium supplementation on insulin sensitivity and other parameters of the metabolic syndrome in an at risk adolescent population., Methods: This study encompassed a participant-blinded, randomized, placebo-controlled, crossover trial. Subjects were 47 healthy adolescent males aged 15-16 years, recruited from secondary schools in lower socio-economic areas with high rates of obesity. Participants received 6 g/day of psyllium or placebo for 6 weeks, with a two-week washout before crossing over. Fasting lipid profiles, ambulatory blood pressure, auxological data, body composition, activity levels, and three-day food records were collected at baseline and after each 6-week intervention. Insulin sensitivity was measured by the Matsuda method using glucose and insulin values from an oral glucose tolerance test., Results: 45 subjects completed the study, and compliance was very high: 87% of participants took >80% of prescribed capsules. At baseline, 44% of subjects were overweight or obese. 28% had decreased insulin sensitivity, but none had impaired glucose tolerance. Fibre supplementation led to a 4% reduction in android fat to gynoid fat ratio (p = 0.019), as well as a 0.12 mmol/l (6%) reduction in LDL cholesterol (p = 0.042). No associated adverse events were recorded., Conclusions: Dietary supplementation with 6 g/day of psyllium over 6 weeks improves fat distribution and lipid profile (parameters of the metabolic syndrome) in an at risk population of adolescent males., Trial Registration: Australian New Zealand Clinical Trials Registry ACTRN12609000888268.

Third harmonic generation (THG) of femtosecond laser pulses in sputtered nanocrystalline TiO2 thin films is investigated. Using layers of graded thickness, the dependence of THG on the film parameters is studied. The maximum THG signal is observed at a thickness of 180 nm. The corresponding conversion efficiency is 26 times larger compared to THG at the air-glass interface. For a demonstration of the capabilities of such a highly nonlinear material for pulse characterization, third-order autocorrelation and interferometric frequency-resolved optical gating (IFROG) traces are recorded with unamplified nanojoule pulses directly from a broadband femtosecond laser oscillator.

Voronoi tessellations have been used to model the geometric arrangement of cells in morphogenetic or cancerous tissues, however, so far only with flat hyper-surfaces as cell-cell contact borders. In order to reproduce the experimentally observed piecewise spherical boundary shapes, we develop a consistent theoretical framework of multiplicatively weighted distance functions, defining generalized finite Voronoi neighborhoods around cell bodies of varying radius, which serve as heterogeneous generators of the resulting model tissue. The interactions between cells are represented by adhesive and repelling force densities on the cell contact borders. In addition, protrusive locomotion forces are implemented along the cell boundaries at the tissue margin, and stochastic perturbations allow for non-deterministic motility effects. Simulations of the emerging system of stochastic differential equations for position and velocity of cell centers show the feasibility of this Voronoi method generating realistic cell shapes. In the limiting case of a single cell pair in brief contact, the dynamical nonlinear Ornstein-Uhlenbeck process is analytically investigated. In general, topologically distinct tissue conformations are observed, exhibiting stability on different time scales, and tissue coherence is quantified by suitable characteristics. Finally, an argument is derived pointing to a tradeoff in natural tissues between cell size heterogeneity and the extension of cellular lamellae.