Time-resolved pump and probe x-ray absorption fine structure spectroscopy at beamline P11 at PETRA III

We report about the development and implementation of a new setup for time-resolved X-ray absorption fine structure spectroscopy at beamline P11 utilizing the outstanding source properties of the low-emittance PETRA III synchrotron storage ring in Hamburg. Using a high intensity micrometer-sized X-ray beam in combination with two positional feedback systems, measurements were performed on the transition metal complex fac-Tris[2-phenylpyridinato-C2,N]iridium(III) also referred to as fac-Ir(ppy)3. This compound is a representative of the phosphorescent iridium(III) complexes, which play an important role in organic light emitting diode (OLED) technology. The experiment could directly prove the anticipated photoinduced charge transfer reaction. Our results further reveal that the temporal resolution of the experiment is limited by the PETRA III X-ray bunch length of ∼103 ps full width at half maximum (FWHM).

Ionization with low-frequency fields in the tunneling regime

Strong-field ionisation surprises with richness beyond current understanding despite decade long investigations. Ionisation with mid-IR light has promptly revealed unexpected kinetic energy structures that seem related to unanticipated quantum trajectories of the electrons. We measure first 3D momentum distributions in the deep tunneling regime (γ = 0.3) and observe surprising new electron dynamics of near-zero momentum electrons and extremely low momentum structures, below the eV, despite very high quiver energies of 95 eV. Such level of high-precision measurements at only 1 meV above the threshold, despite 5 orders higher ponderomotive energies, has now become possible with a specifically developed ultrafast mid-IR light source in combination with a reaction microscope, thereby permitting a new level of investigations into mid-IR recollision physics.

NAIS: nuclear activation-based imaging spectroscopy

In recent years, the development of high power laser systems led to focussed intensities of more than 10(22) W/cm(2) at high pulse energies. Furthermore, both, the advanced high power lasers and the development of sophisticated laser particle acceleration mechanisms facilitate the generation of high energetic particle beams at high fluxes. The challenge of imaging detector systems is to acquire the properties of the high flux beam spatially and spectrally resolved. The limitations of most detector systems are saturation effects. These conventional detectors are based on scintillators, semiconductors, or radiation sensitive films. We present a nuclear activation-based imaging spectroscopy method, which is called NAIS, for the characterization of laser accelerated proton beams. The offline detector system is a combination of stacked metal foils and imaging plates (IP). After the irradiation of the stacked foils they become activated by nuclear reactions, emitting gamma decay radiation. In the next step, an autoradiography of the activated foils using IPs and an analysis routine lead to a spectrally and spatially resolved beam profile. In addition, we present an absolute calibration method for IPs.

The Stockholm Diabetes Intervention Study (SDIS): 18 months' results

Patients with insulin-dependent diabetes mellitus (IDDM), non-proliferative retinopathy and unsatisfactory blood glucose control were randomized to intensified conventional treatment (ICT, 48 patients) or regular treatment (RT, 54 patients) for a 5-year study. After 18 months the glycosylated hemoglobin (HbA1c) was reduced in both groups, but significantly more in the ICT group (p = 0.00005). Thirty of the RT patients and 16 from the ICT group deteriorated as to retinopathy (p = 0.024). Microalbuminuria appeared more often in the RT patients (p = 0.023), and nerve conduction velocities were significantly reduced only in the RT group (p between 0.0005 and 0.047). Serious hypoglycemia was more common in the ICT patients (p = 0.003). The progression of diabetic late complications was thus slowed down by intensified treatment, but at the price of an increased frequency of serious hypoglycemia.

Tying pay to performance: one critical care unit's approach

This article describes development and testing of a tool for determining an appropriate reward for staff performance in a critical care area. Outlined is the process of identifying and quantifying appropriate merit increases based on bedside performance as well as participation in other unit, hospital, professional and community activities. Positive results are reported after one- and two-year use.

Intensified conventional insulin treatment and neuropsychological impairment

OBJECTIVE

To assess whether intensified insulin treatment, with an increased frequency of hypoglycaemic episodes, leads to cognitive deterioration.

DESIGN

Prospective randomised trial of intensified conventional treatment and standard treatment.

SETTING

Outpatient clinic for patients with insulin dependent diabetes.

SUBJECTS

96 patients with insulin dependent diabetes, high blood glucose concentrations, and non-proliferative retinopathy were randomised to intensified conventional treatment (n = 44) or standard treatment (n = 52).

MAIN OUTCOME MEASURES

Glycated haemoglobin concentration (metabolic control); the number of hypoglycaemic episodes reported by patients at each visit; results of computerised neuropsychological tests performed at entry and after five years.

RESULTS

Mean glycated haemoglobin concentration during the study was 7.2% (SE 0.1%) with intensified conventional treatment and 8.7 (0.1%) with standard treatment (p less than 0.001). During five years 34 (77%, 95% confidence interval 53% to 100%) of the patients given intensified treatment and 29 (56%, 36% to 75%) of the others had at least one episode of serious hypoglycaemia (p less than 0.05). The intensified conventional treatment group had a mean of 1.1 episodes of serious hypoglycaemia per patient per year compared with 0.4 episodes in the standard treatment group. Results of the neuropsychological tests were similar in the two groups after five years.

CONCLUSIONS

Intensified conventional insulin treatment led to lower blood glucose concentrations and a higher frequency of hypoglycaemic episodes, but patients showed no signs of cognitive deterioration.

Intensified conventional insulin treatment retards the microvascular complications of insulin-dependent diabetes mellitus (IDDM): the Stockholm Diabetes Intervention Study (SDIS) after 5 years

Ninety-six patients with insulin-dependent diabetes mellitus (IDDM) and non-proliferative retinopathy were randomized to intensified conventional treatment (ICT) (n = 44) or regular treatment (RT) (n = 52), and followed up for 5 years. HbA1c decreased from 9.5 +/- 0.2% (mean value +/- SEM) to 7.2 +/- 0.1% in the ICT group, and from 9.4 +/- 0.2% to 8.7 +/- 0.1% in the RT group (difference between the groups, P less than 0.001). Retinopathy increased in both groups (P less than 0.001), but after 5 years it was worse in the RT group (P less than 0.05). The urinary albumin excretion rate was higher in the RT group than in the ICT group after 5 years (239.9 +/- 129.7 micrograms min-1 vs. 46.0 +/- 26.1 micrograms min-1, P less than 0.05). Eight RT patients developed manifest nephropathy, compared with none in the ICT group (P less than 0.01). After 5 years the conduction velocities of the sural (P less than 0.05), peroneal (P less than 0.01) and tibial (P less than 0.001) nerves were lower in the RT group. The respiratory sinus arrhythmia was 12.1 +/- 1.2 beats min-1 in the RT group and 16.7 +/- 1.4 beats min-1 in the ICT group at the end of the study (P less than 0.01). The increases in retinopathy (P less than 0.01), nephropathy (P less than 0.01) and neuropathy (P less than 0.001) were all related to the mean HbA1c value during the study. Smoking habits only influenced the progression of retinopathy (P less than 0.05). Serious hypoglycaemia occurred in 34 ICT patients and 29 RT patients (242 and 98 episodes, respectively) (P less than 0.05). Whereas weight was stable in the RT group, the body mass index increased by 5.8% in the ICT group (P less than 0.01). In conclusion, microvascular complications of diabetes were retarded by intensified conventional insulin treatment. However, such treatment increased the frequency of serious hypoglycaemia, and led to an increase in body weight.

Hypoglycaemic episodes during intensified insulin treatment: increased frequency but no effect on cognitive function

Ninety-seven patients with insulin dependent diabetes mellitus (IDDM) were randomized to intensified conventional treatment (ICT, n = 44) or regular treatment (RT, n = 53). The mean HbA1c level (+/- SEM) was reduced from 9.5 +/- 0.2% to 7.4 +/- 0.1% in the ICT group (P less than 0.001), and from 9.4 +/- 0.2% to 9.0 +/- 0.2% (P less than 0.01) in the RT group. The difference between the groups was significant (P less than 0.001). During a period of 3 years, 57% of the ICT patients (95% confidence interval 44-73%) and 23% of the RT patients (95% CI, 11-34%) (P less than 0.001) had at least one episode of serious hypoglycaemia, with the need for third-party assistance or resulting in coma. Eighteen of the 32 ICT patients who initially had adrenergic symptoms during hypoglycaemia changed to predominantly neuroglycopenic symptoms. This was the case with only 8 of 38 RT patients (P less than 0.01). The change in symptoms was related to the increased frequency of serious hypoglycaemia, but neither symptoms nor frequency of hypoglycaemia bor any relationship to insulin dose, body mass index, duration of diabetes or autonomic nerve function. The results of several neuropsychological tests did not differ between the groups at baseline, and did not change during the study. There were no signs of deteriorating cognitive function in the patients with serious hypoglycaemic episodes.

Metabolic control and complications over 3 years in patients with insulin dependent diabetes (IDDM): the Stockholm Diabetes Intervention Study (SDIS)

In a planned 5-year study, 97 patients with insulin dependent diabetes mellitus (IDDM), non-proliferative retinopathy and unsatisfactory blood glucose control were monitored for 3 years. The patients were randomized to an intensified conventional treatment (ICT, n = 44) or a regular treatment (RT, n = 53) group. HbA1c (normal range 3.9-5.7%) was reduced from 9.5 +/- 0.2 (mean value +/- SEM) to 7.4 +/- 0.1% in the ICT group (P = 0.0001), and from 9.5 +/- 0.2 to 9.0 +/- 0.2% in the RT group (P = 0.004). Nerve conduction velocities in the sural and peroneal nerves (P = 0.01-0.0001) were impaired in the RT group, but not in the ICT group. Retinopathy increased in both groups. The condition of 22 ICT patients (50%, 95% confidence interval 34-66%) and 37 RT patients (73%, 61-84%) deteriorated with regard to at least one microvascular complication (retinopathy, nephropathy, neuropathy) (P = 0.024). Lower HbA1c levels during the study significantly reduced the risk of deterioration (P = 0.01). In total, 57% of the ICT patients had at least one episode of serious hypoglycaemia, compared with 23% in the RT group (P = 0.001). The patients in the ICT group also gained weight (P = 0.0001). Improved blood glucose control slowed down the progression of microangiopathy during a 3-year period in patients with non-proliferative retinopathy, but at the price of an increased frequency of serious hypoglycaemic episodes, and some gain in body weight.