Photophysical dynamics of a binuclear Cu(i)-emitter on the fs to µs timescale, in solid phase and in solution.

Understanding subtle aspects of photophysical behavior is the key to design and synthesize new and improved luminescent materials. We contribute to this with an in-depth photophysical characterization of the binuclear copper complex Cu(i)-NHetPHOS-tris-m-tolylphosphine (1), a member of a recently established emitter class for ultra-efficient, printed organic light-emitting diodes (OLEDs). To this end we studied 1 in solution and in solid form, i.e. neat film and KBr-pellet, by means of femtosecond time-resolved transient absorption/reflectivity, time-correlated single photon counting (TCSPC), and nanosecond time-resolved step-scan FTIR spectroscopy. Using these methods, we explore the photoinduced dynamics from ultrafast Franck-Condon state deactivation until the decay of the luminescent states. Upon photoexcitation, we observed multiexponential dynamics in both solution (e.g. acetonitrile 0.8 ps, 59 ps, 3 ns, 11-13 ns) and in solid state (e.g. neat film 0.3 ps, 35 ps, 670 ps, 0.5-1 µs, 3.5-4.5 µs) with four to five time-constants that significantly depend on the type of sample. Quantum chemical calculations at the DFT level in combination with step-scan vibrational spectroscopy provided structural information about the electronic ground state S0 and the lowest lying excited state T1, and show that the latter is populated within 1 µs after photoexcitation. We found thermally activated delayed fluorescence (TADF) for this complex, which has been suggested to be the cause for its high efficiency in printed OLED devices. The results suggest that non-radiative processes, lowering the luminescence quantum yield in solution, are active on the ns to µs timescale.

[Methohexital for analgosedation of ventilated intensive care patients : prospective nonrandomized single center observational study on incidence of delirium]. / Methohexital zur Analgosedierung bei beatmeten Intensivpatienten : Prospektive nichtrandomisierte "Single-center"-Observationsstudie zur Delirinzidenz.

BACKGROUND: Delirium is defined by the Diagnostic and Statistical Manual of Mental Disorders, fourth edition, text revision (DSM-IV-TR) as a potentially reversible disturbance of consciousness and a change of cognition caused by a medical condition, drug intoxication, or medication side effect. Delirium affects up to 80 % of intensive care unit (ICU) patients and is associated with increased morbidity and mortality. One risk factor for development of delirium in ventilated intensive care unit patients is sedation. The German S3 guidelines on "Analgesie, Sedierung und Delirmanagement in der Intensivmedizin" (analgesia, sedation and delirium management in intensive care medicine) of the DGAI (German Society for Anesthesiology and Intensive Care Medicine) and the DIVI (German Interdisciplinary Association for Intensive Care and Emergency Medicine) recommend midazolam and propofol for sedation, although both drugs are associated with a high incidence of delirium. AIM: Within the framework of this study the question arose whether the barbiturate methohexital could be associated with a lower incidence of delirium in comparison to midazolam or propofol in analgosedated and ventilated ICU patients. MATERIAL AND METHODS: This was a prospective nonrandomized observational cohort study in a mixed medical surgical intensive care unit. Patients ventilated within 72 h after admittance were consecutively allocated to either propofol/remifentanil versus methohexital/remifentanil (expected ventilation duration ≤ 7 days) or midazolam/fentanyl versus methohexital/fentanyl (expected ventilation duration > 7 days) by the attending senior consultant anesthetist at the time of admission and/or intubation. Primary endpoint was delirium at any time during the ICU stay. Delirium was checked every 8 h by ICU nurses using the intensive care delirium screening checklist (ICDSC), with delirium defined as ICDSC ≥ 4 points. Before evaluation of the ICDSC the Richmond agitation sedation scale (RASS) score and the visual analogue scale for pain (VAS target ≤ 4) were measured. To assure reliable evaluation of the ICDSC, the RASS score of the patient at the time of evaluation had to be ≥ - 2. Assuming an incidence of delirium in the midazolam group of 70 % and in the methohexital group of 35 %, 16 patients were needed each in the midazolam/fentanyl and the methohexital/fentanyl cohorts (p = 0.05, ß = 0.1). Assuming an incidence of delirium in the propofol group of 50 % and in the methohexital group again of 35 %, 94 patients were needed in the propofol/remifentanil and methohexital/remifentanil groups, respectively (p = 0.05, ß = 0.1). RESULTS: A total of 222 patients were evaluated, 34 in the methohexital vs. midazolam group and 188 in the methohexital vs. propofol group. Out of 16 patients sedated with midazolam, 15 developed delirium (94 %) in contrast to only 5 out of 18 patients sedated with methohexital (28 %). Thus compared to midazolam the sedation with methohexital reduced the incidence of delirium by 66 % (p < 0.001) corresponding to a number needed to treat (NNT) of 1.5. Out of 94 patients in the propofol/remifentanil group, 64 developed delirium (68 %) in contrast to only 23 out of 94 in the methohexital/remifentanil group (24 %). Thus compared to propofol the sedation with methohexital reduced the incidence of delirium by 44 % (p < 0.001), corresponding to an NNT of 2.5. CONCLUSION: Sedation with methohexital compared to midazolam or propofol reduced the incidence of delirium by more than 50 % in ventilated ICU patients.

High throughput in vitro and in vivo screening of inland waters of Southern California.

The impact of unmonitored contaminants, also known as contaminants of emerging concern (CECs), on freshwater streams remains largely uncharacterized. Water samples from 31 streams representing urban, agricultural and undeveloped (i.e., open space) land use in Southern California (USA) were analyzed for in vitro and in vivo bioactivity. The extent and magnitude of bioactivity screened using endocrine-responsive cell bioassays and a fish embryo screening assay were low. In contrast, a wider gradient of responses for the aryl hydrocarbon receptor (AhR) assay was observed, which was negatively correlated with a measure of benthic community structure. Both aromatic and non-aromatic CECs were tentatively identified in these samples, but polycyclic aromatic hydrocarbons (PAHs), known AhR agonists in urban environments, were not present at detectable levels. These results suggest that a combination of in vitro and in vivo show potential as screening techniques for biological condition in situ, but that more advanced, comprehensive analytical methods are needed to identify bioactive contaminants.

Intravenous angiography using scanned projection radiography: preliminary investigation of a new method.

The use of digital subtraction techniques combined with fluoroscopy has rekindled interest in arteriography using intranvenous injections of contrast media. A new method is proposed for intravenous angiography in which an x-ray source and xenon detector array from a computed tomographic (CT) scanner are used to scan a region of interest to produce projection image. In order to provide adequate visualization of small concentrations of iodine in blood vessels, a subtraction scheme is used to remove the contribution from overlapping soft tissue and bone. Initial experiments with a temporal subtraction algorithm on phantoms have demonstrated the ability to image simulated blood vessels of 1.7-mm diameter containing dilute diatrizoate with an iodine concentration of 3.7 mg/cc, at an exposure of less than 100 mR. Vascular structures 5-8 mm in diameter have been imaged in dogs with iodine concentrations of less than 37 mg/cc using temporal subtraction. Principal advantages of the method over other film or fluoroscopic subtraction techniques are: 1) wide dynamic range an low noise of the (CT) detectors, providing excellent iodine sensitivity; 2) high scatter rejection; and 3) efficient utilization of x-ray dose.

Noninvasive glucose measurement by monitoring of scattering coefficient during oral glucose tolerance tests. Non-Invasive Task Force.

BACKGROUND: Continuous glucose monitoring by means of optical glucose sensors would allow patients with diabetes to check their metabolic control to their convenience. In an earlier study, we showed that noninvasive glucose monitoring is feasible for rapid changes in blood glucose by means of measuring the scattering coefficient of human skin. In this study, we investigated whether also slower changes in blood glucose, this time induced by an oral glucose load, can also be monitored by this approach. METHODS: Five healthy subjects and 13 patients with type 2 diabetes have been given a 75-g oral glucose load. Portable noninvasive systems were used to measure the skin tissue scattering coefficient. For this purpose, two optical sensor heads were attached directly to the skin of each volunteer. Light was applied to the skin and the reflected light intensity was registered. RESULTS: In 8 of 10 measurements, correlation of changes in scattering coefficient with changes in glycemia was acceptable. In 19 of 26 measurements (73%) of patients with type 2 diabetes the observed changes in the scattering coefficient also correlated in acceptable manner. The accordance between the simultaneous measurements of the two sensor heads was acceptable in 13 of 18 volunteers and patients studied. There were virtually no differences in the quality of the measurements between healthy volunteers and patients with diabetes. CONCLUSIONS: This study shows that also slow changes in blood glucose induced by an oral glucose load can be monitored by registration of scattering coefficient changes. It remains to be elucidated why this has not been possible in all experiments.

Effect of various vaccination procedures on shedding, latency, and reactivation of attenuated and virulent pseudorabies virus in swine.

Various procedures of vaccination for pseudorabies were compared for their effects on shedding, latency, and reactivation of attenuated and virulent pseudorabies virus. The study included 6 groups: group 1 (10 swine neither vaccinated nor challenge-exposed), group 2 (20 swine not vaccinated, but challenge-exposed), and groups 3 through 6 (10 swine/group, all vaccinated and challenge-exposed). Swine were vaccinated with killed virus IM (group 3) or intranasally (group 4), or with live virus IM (group 5) or intranasally (group 6). The chronologic order of treatments was as follows: vaccination (week 0), challenge of immunity by oronasal exposure to virulent virus (week 4), biopsy of tonsillar tissue (week 12), treatment with dexamethasone in an attempt to reactivate latent virus (week 15), and necropsy (week 21). Vaccination IM with killed or live virus and vaccination intranasally with live virus mitigated clinical signs and markedly reduced the magnitude and duration of virus shedding after challenge exposure. Abatement of signs and shedding was most pronounced for swine that had been vaccinated intranasally with live virus. All swine, except 4 from group 2 and 1 from group 4, survived challenge exposure. Only vaccination intranasally with live virus was effective in reducing the magnitude and duration of virus shedding after virus reactivation. Vaccination intranasally with killed virus was without measurable effect on immunity. Of the 55 swine that survived challenge exposure, 54 were shown subsequently to have latent infections by use of dexamethasone-induced virus reactivation, and 53 were shown to have latent infections by use of polymerase chain reaction (PCR) with trigeminal ganglia specimens collected at necropsy. Fewer swine were identified by PCR as having latent infections when other tissues were examined; 20 were identified by testing specimens of olfactory bulbs, 4 by testing tonsil specimens collected at necropsy, and 4 by testing tonsillar biopsy specimens. Eighteen of the 20 specimens of olfactory bulbs and 3 of the 4 tonsil specimens collected at necropsy in which virus was detected by PCR were from swine without detectable virus-neutralizing antibody at the time of challenge exposure. One pig that had been vaccinated intranasally with live virus shed vaccine virus from the nose and virulent virus from the pharynx concurrently after dexamethasone treatment. Evaluation of both viral populations for unique strain characteristics failed to provide evidence of virus recombination.

Florida Community Health Purchasing Alliances.

Until recently, many small businesses in Florida were unable to provide any type of health coverage to their employees because of high insurance rates. With the development of the Community Health Purchasing Alliance, the rates have decreased, enabling employers to offer health insurance to their workers. Often, employees can choose from a variety of health plans in terms of coverage and price.

A neural network approach to the analysis and classification of human craniofacial growth.

Planning of treatment in the field of orthodontics and maxillo-facial surgery is largely dependent on the individual growth of a patient. In the present work, the growth of 43 orthodontically untreated children was analysed by means of lateral cephalograms taken at the ages of 7 and 15. For the description of craniofacial skeletal changes, the concept of tensor analysis and related methods have been applied. Thus the geometric and analytical shortcomings of conventional cephalometric methods have been avoided. Through the use of an artificial neural network, namely self-organizing neural maps, the resultant growth data were classified and the relationships of the various growth patterns were monitored. As a result of self-organization, the 43 children were topologically ordered on the emerging map according to their craniofacial size and shape changes during growth. As a new patient can be allocated on the map, this type of network provides a frame of reference for classifying and analysing previously unknown cases with respect to their growth pattern. If landmarks are used for the determination of growth, the morphometric methods applied as well as the subsequent visualization of the growth data by means of neural networks can be employed for the analysis and classification of growth-related skeletal changes in general.

How physician networks are selling themselves.

A growing number of physicians are creating discount networks due to the anger they feel about their loss of professional autonomy and financial compensation to managed care. They are seeking a niche among patients who lack adequate health insurance coverage or are dissatisfied with their plans. To win patients, the physician networks are marketing services that are deeply discounted.

Purchasing alliances: still in the picture.

In 1993, purchasing alliances were a hotbed of legislative activity. Today, 13 states have enacted laws establishing them. Here's a brief update of how these alliances are working.

Latency of a thymidine kinase-negative pseudorabies vaccine virus detected by the polymerase chain reaction.

Latent viral DNA was detected by the polymerase chain reaction in trigeminal ganglia of all of 10 pigs that were necropsied 81 or more days after they had been infected intranasally with a thymidine kinase-negative (TK-) vaccine strain of pseudorabies virus (PRV). Failure to reactivate virus from any of the same pigs by earlier treatment with dexamethasone suggested that even though latency can be established with TK- PRV, subsequent reactivation may be a relatively rare event.

Manipulation of CT data for temporal-bone imaging.

The usefulness of CT in studying the temporal bone is limited by spatial resolution and by the range of absorption coefficients which can be displayed. The authors evaluated the effect of four types of data manipulation: (a) reconstruction of data with different convolution filters (target reconstruction), (b) extension of the range of CT numbers, (c) mathematical filtration to enhance edges, and (d) correction for beam hardening. Target reconstruction and extension of the CT range significantly improved visualization of small structures in the temporal bone.

Failure to thrive, wasting syndrome, and immunodeficiency in rabies: a hypophyseal/hypothalamic/thymic axis effect of rabies virus.

Studies of rabies virus in several animal models consistently showed hypothalamic infection, hypophyseal infection, dramatic growth impairment (in the form of failure to thrive), wasting syndrome, and immune depletion. Rabies virus infection was studied through routine monoclonal antinucleocapsid antibody immunofluorescence and through a peroxidase-antiperoxidase immunoperoxidase method. The latter was modified to detect the in situ production of growth hormone by uninfected and rabies virus-infected adeno-a-pituicytes (with confirmation of the results both in vivo and in vitro). Infection with rabies virus made the specialized pituicytes produce less growth hormone. Growth before rabies virus infection and its reduction due to infection were investigated in a linear regression model. The fit was statistically significant (P less than .05) in all species studied: mouse, rat, rabbit, cow, and cat. Immune depression was studied in terms of alterations in the immunotopography of the thymus and also the specific T- and B-cell homing areas of the spleen (although spleen data are not presented here). On the basis of these results and a thorough review of wasting syndromes encountered in other diseases, a primary failure to thrive and an ensuing wasting syndrome were described and characterized for rabies, and their origin was assigned to a dysfunction of the hypophyseal/hypothalamic/thymic axis associated with at least (but not necessarily only) one of the centrally controlled growth hormones.

A new method for the histochemical demonstration of O-acyl sugars in human colonic epithelial glycoproteins.

A new general method has been developed for the specific histochemical identification of O-acyl sugars in any epithelial glycoprotein. These sugars include hexose, 6-deoxyhexose and N-acetylhexosamine with an ester substituent(s) located on a potential vicinal diol(s). In the procedure reported [the periodic acid-borohydride reduction-saponification-selective periodate oxidation-borohydride reduction-periodic acid-Schiff (PA-Bh-KOH-PA*-Bh-PAS) method] the initial PA-Bh treatment renders vicinal diols located on either sialic acid or neutral sugars PAS unreactive. In the subsequent steps ester substituents are removed from both O-acyl sugars and O-acyl sialic acids by saponification (KOH), sialic acid vicinal diols are selectively removed by the PA*-Bh sequence and O-acyl sugars are stained with the PAS technique. This method has the advantage that the results are obtained with a single section and the results are either positive or negative. Consequently, it is superior to the three indirect methods investigated because it does not require an observer to compare the intensity or the shade of the staining obtained with serial sections. Using the PA-Bh-KOH-PA*-Bh-PAS method we have demonstrated, for the first time, that O-acyl sugars occur in the epithelial goblet cell glycoproteins of adult human colon. The effect of the presence of O-acyl sugars on the interpretation of a number of other methods for the histochemical investigation of glycoproteins is discussed. It is recommended that the results obtained with the PA-Bh-KOH-PA*-Bh-PAS method be evaluated before histochemical procedures for the investigation of neutral sugars and O-acyl sialic acids are selected.