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.

Effects of the dual peroxisome proliferator-activated receptor activator aleglitazar in patients with Type 2 Diabetes mellitus or prediabetes

BACKGROUND

Insulin-resistant states, including type 2 diabetes (T2D) and prediabetes, are associated with elevated cardiovascular (CV) risk. Aleglitazar is a dual peroxisome proliferator-activated receptor α/γ agonist with favorable insulin-sensitizing and glucose-lowering actions, favorable effects on blood lipids, and an acceptable safety profile in short-time studies. Therefore, it was hypothesized that aleglitazar would reduce CV morbidity and mortality in patients with T2D mellitus and prediabetes (defined as glycosylated hemoglobin ≥5.7% to <6.5%) with previous CV complications.

STUDY DESIGN

ALEPREVENT was a phase III, multicenter, randomized, double-blind, trial comparing aleglitazar 150 μg or placebo daily in patients with T2D or prediabetes with established, stable CV disease. The intended sample size was 19,000 with a primary efficacy measure of major adverse CV events. However, the trial was halted prematurely after 1,999 patients had been randomized because of futility and an unfavorable benefit risk ratio in another CV outcomes trial evaluating aleglitazar.

RESULTS

At study termination after 58 ± 38 days of treatment, data had been collected from 1,996 patients (1,581 with T2D and 415 with pre-T2D). Despite the brief duration of treatment, aleglitazar induced favorable changes in glycosylated hemoglobin and blood lipids, similar for participants with T2D or prediabetes. However, compared with placebo, aleglitazar increased the incidence of hypoglycemia (86 vs 166; P < .0001), and muscular events (3 vs12; P = .012).

CONCLUSIONS

Even within a short duration of exposure, aleglitazar was associated with excess adverse events, corroborating the findings of a larger and longer trial in T2D. Coupled with the previous failure of several other peroxisome proliferator-activated receptor α/γ activators, this class now holds little promise for CV therapeutics.

Effect of aleglitazar on cardiovascular outcomes after acute coronary syndrome in patients with type 2 diabetes mellitus: the AleCardio randomized clinical trial

IMPORTANCE

No therapy directed against diabetes has been shown to unequivocally reduce the excess risk of cardiovascular complications. Aleglitazar is a dual agonist of peroxisome proliferator-activated receptors with insulin-sensitizing and glucose-lowering actions and favorable effects on lipid profiles.

OBJECTIVE

To determine whether the addition of aleglitazar to standard medical therapy reduces cardiovascular morbidity and mortality among patients with type 2 diabetes mellitus and a recent acute coronary syndrome (ACS).

DESIGN, SETTING, AND PARTICIPANTS

AleCardio was a phase 3, multicenter, randomized, double-blind, placebo-controlled trial conducted in 720 hospitals in 26 countries throughout North America, Latin America, Europe, and Asia-Pacific regions. The enrollment of 7226 patients hospitalized for ACS (myocardial infarction or unstable angina) with type 2 diabetes occurred between February 2010 and May 2012; treatment was planned to continue until patients were followed-up for at least 2.5 years and 950 primary end point events were positively adjudicated.

INTERVENTIONS

Randomized in a 1:1 ratio to receive aleglitazar 150 µg or placebo daily.

MAIN OUTCOMES AND MEASURES

The primary efficacy end point was time to cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke. Principal safety end points were hospitalization due to heart failure and changes in renal function.

RESULTS

The trial was terminated on July 2, 2013, after a median follow-up of 104 weeks, upon recommendation of the data and safety monitoring board due to futility for efficacy at an unplanned interim analysis and increased rates of safety end points. A total of 3.1% of patients were lost to follow-up and 3.2% of patients withdrew consent. The primary end point occurred in 344 patients (9.5%) in the aleglitazar group and 360 patients (10.0%) in the placebo group (hazard ratio, 0.96 [95% CI, 0.83-1.11]; P = .57). Rates of serious adverse events, including heart failure (3.4% for aleglitazar vs 2.8% for placebo, P = .14), gastrointestinal hemorrhages (2.4% for aleglitazar vs 1.7% for placebo, P = .03), and renal dysfunction (7.4% for aleglitazar vs 2.7% for placebo, P < .001) were increased.

CONCLUSIONS AND RELEVANCE

Among patients with type 2 diabetes and recent ACS, use of aleglitazar did not reduce the risk of cardiovascular outcomes. These findings do not support the use of aleglitazar in this setting with a goal of reducing cardiovascular risk.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01042769.

Polypeptide expression in prostate hyperplasia and prostate adenocarcinoma

Cells were collected from prostate hyperplasias (n = 6) and prostate carcinomas (n = 6) and subjected to two-dimensional gel electrophoresis (2-DE). The resulting polypeptide patterns were analysed with the PDQUEST computer software. Malignant tumors showed significant increases in the level of expression of proliferating cell nuclear antigen (PCNA), calreticulin, HSP 90 and pHSP 60, oncoprotein 18(v), elongation factor 2, glutathione-S-transferase pi (GST-pi), superoxide dismutase and triose phosphate isomerase. In addition, decreases in the levels of tropomyosin-1 and 2 and cytokeratin 18 were observed in prostate carcinomas compared to prostate hyperplasias. This pattern of alterations is similar to that observed in other carcinomas in our previous studies. All malignant tumors showed simultaneous alterations in 5 or more of 9 markers studied, whereas only one case of benign hyperplasia showed alterations in 5 markers. The EST-data base for prostate tumors available from NCI (CGAP) was searched for the expression of the mRNAs corresponding to proteins identified in our gels. Large differences in the relative expression of mRNAs and proteins were observed. Our data show alterations in the pattem of polypeptide expression in prostate carcinomas which are similar to those observed in other carcinomas.

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.

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.

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.

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.

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.

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.

Histochemical studies of epithelial cell glycoproteins in normal rat colon

Two general classes of glycoproteins have been identified in the colonic epithelial cells of the Sprague Dawley rat. Glycoproteins belonging to the first of these classes contain sialic acids both with and without side chain o-acyl substituents, abundant o-sulphate ester and 'neutral sugars' (hexose, 6-deoxyhexose or N-acetyl hexosamine residues) with oxidisable vicinal diols and are located in the goblet cells of the descending colon and in goblet cells populating the upper halves of the crypts of the ascending colon. In the descending colon, the sulphosialoglycoproteins in the goblet cells in the base of the crypts contain sialic acids without side chain o-acyl substituents. It appears that as these cells migrate up the crypts, there is o-acylation of the side chains of the sialic acids of the glycoproteins and an increase in the quantity of 'neutral sugars' without a corresponding increase in sialic acid. Glycoproteins with similar properties to those of the goblet cells of the upper halves of the crypts of the descending colon, but containing less sulphate, are found in the goblet cells of the upper half of the crypts of the ascending colon. The second general class of glycoproteins contain sialic acids all, or almost all of which, are substituted at position C8 and only relatively small quantities of sulphate. They are located in the mucous cells of the descending colon, the deep crypt secretory cells of the ascending colon and the columnar absorptive cell brush border.(ABSTRACT TRUNCATED AT 250 WORDS)

A new histochemical method for the selective periodate oxidation of total tissue sialic acids

Evaluation of the intensity of the periodic acid-Schiff (PAS) staining produced following oxidation for 1 h at 4 degrees C with 0.4 mM periodic acid in approximately 1 M hydrochloric acid indicated that this reagent completely oxidized all available sialic acid residues of either the sialo- or sialosulphoglycoproteins of human and rat colon or the sialoglycoproteins of rat sublingual gland. These conditions produced no visible Schiff staining of either neutral macromolecules or vicinal diols located on hexose, 6-deoxyhexose or N-acetylhexosamine residues ('neutral sugars') of sialo- and sialosulphoglycoproteins. Furthermore, there was no extraction of epithelial glycoproteins or de-O-acylation of side chain substituted sialic acid residues. These data demonstrate that 0.4 mM periodic acid in approximately 1 M hydrochloric acid can be used as a specific reagent for the selective visualization of sialic acids in the PAS procedure. Studies of the mechanism of the oxidation of neutral sugars with 0.4 mM periodic acid in approximately 1 M hydrochloric acid indicated that their lack of PAS reactivity was not due to the production of Schiff unreactive hemiacetals or hemialdals. It is suggested that the selectivity of 0.4 mM periodic acid in approximately 1 M hydrochloric acid is a result of an increase in the rate of the oxidation of the sialic acid residues together with a decrease in the rate of oxidation of neutral sugars.

Histochemical procedures for the simultaneous visualization of neutral sugars and either sialic acid and its O-acyl variants or O-sulphate ester. II. Methods based upon the periodic acid-phenylhydrazine-Schiff reaction

Four methods based upon the periodic acid-phenylhydrazine-Schiff reaction have been developed for the simultaneous visualization of neutral sugars with periodate oxidizable vicinal diols (hexose, 6-deoxyhexose, N-acetylhexosamine) and either sialic acids or side chain O-acyl sialic acids. In the first of these procedures, the saponification-periodic acid oxidation-2,4-dinitrophenylhydrazine-Azure A-Schiff-saponification (KOH-PA-DNPH-Az-KOH) method, all sialic acids stain Azure blue, neutral sugars with oxidizable vicinal diols stain yellow and mixtures of such components stain in various shades of green. In the second technique, periodic acid oxidation-2,4-dinitrophenylhydrazine-Azure A Schiff-saponification (PA-DNPH-Az-KOH), Azure Blue staining is confined to sialic acids without side chain substituents or which have an O-acyl substituent at position C7, while in the third method, the selective periodate oxidation-borohydride reduction-saponification-periodic acid oxidation-2,4-dinitrophenyl hydrazine-Azure A-Schiff-saponification (PA-Bh-KOH-PA-DNPH-Az-KOH) technique, only sialic acids with O-acyl substituents at positions C7, C8 or C9 (or which have two or three O-acyl side chain substituents) stain Azure blue. Finally in the fourth procedure, periodic acid oxidation-2,4-dinitrophenylhydrazine-Azure A-Schiff-saponification-borohydride reduction-periodic acid oxidation-Schiff (PA-DNPH-Az-KOH-Bh-PAS), sialic acids without side chain substituents or which have O-acyl substituents at C7 stain Azure blue, sialic acids substituted at position C8 or C9 (or which are di- or tri-substituted) stain magenta and neutral sugars stain yellow. Where mixtures of these components are present, a wide range of colours is obtained.

Histochemical procedures for the simultaneous visualization of neutral sugars and either sialic acid and its side chain O-acyl variants or O-sulphate ester. I. Methods based upon the selective periodate oxidation of sialic acids

Five new methods, based upon the selective oxidation of sialic acid residues with 0.4 mM periodic acid in approximately 1 M hydrochloric acid at 4 degree C for 1 h (PA), have been devised for the simultaneous visualization of neutral sugars and either sialic acid and its side chain O-acyl variants or O-sulphate ester. In the first of these, the selective periodate oxidation-borohydride reduction-saponification-selective periodate oxidation-Thionin Schiff-saponification-borohydride reduction-periodic acid-Schiff (PA-Bh-KOH-PA-T-KOH-Bh-PAS) technique, sialic acids with O-acyl substituents at C7, C8 or C9 (or which have two of three side chain O-acyl substituents) stain blue while neutral sugars with periodate-sensitive vicinal diols (hexose, 6-deoxyhexose, and N-acetylhexosamine) stain magenta. The second method, the saponification-selective periodate oxidation-Thionin Schiff-saponification-borohydride reduction-periodic acid-Schiff (KOH-PA-T-KOH-Bh-PAS), stains all sialic acids blue and neutral sugars magenta. In the third procedure, the selective periodate oxidation-Thionin Schiff-borohydride reduction-periodic acid-Schiff-saponification (PA-T-Bh-PAS-KOH) method, sialic acids without side chain substituents (or which have an O-acyl substituent at C7) stain blue and neutral sugars stain magenta. In the fourth method, the saponification-selective periodate oxidation-borohydride reduction-Alcian Blue pH 1.0-periodic acid-Schiff (KOH-PA-Bh-AB1.0-PAS) technique, O-sulphate esters stain aquamarine blue and neutral sugars stain magenta. In all of these techniques mixtures of the components stain in various shades of purple.(ABSTRACT TRUNCATED AT 250 WORDS)

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.