Triplet carbenes with transition-metal substituents.

The extraordinary advances in carbene (R-C-R) chemistry have been fuelled by strategies to stabilize the electronic singlet state via π interactions. In contrast, the lack of similarly efficient approaches to obtain authentic triplet carbenes with appreciable lifetimes beyond cryogenic temperatures hampers their exploitation in synthesis and catalysis. Transition-metal substitution represents a potential strategy, but metallocarbenes (M-C-R) usually represent high-lying excited electronic configurations of the well-established carbyne complexes (M≡C-R).

A Tetracarbene Iron(II) Complex with a Long-lived Triplet Metal-to-Ligand Charge Transfer State due to a Triplet-Triplet Barrier.

Mixed N-heterocyclic carbene (NHC) / pyridyl iron(II) complexes have attracted a great deal of attention recently because of their potential as photocatalysts and light sensitizers made from Earth-abundant elements. The most decisive challenge for their successful implementation is the lifetime of the lowest triplet metal-to-ligand charge transfer state (MLCT), which typically decays via a triplet metal-centered (MC) state back to the ground state. We reveal by variable-temperature ultrafast transient absorption spectroscopy that the tripodal iron(II) bis(pyridine) complex isomers trans- and cis-[Fe(pdmi)] with four NHC donors show MLCT→MC population transfers with very different barriers and rationalize this by computational means.

Pediatric Conjunctivitis: A Review of Clinical Manifestations, Diagnosis, and Management.

Conjunctivitis is a common pediatric problem and is broadly divided into infectious and non-infectious etiologies. Bacterial conjunctivitis makes up the majority of cases in children and often presents with purulent discharge and mattering of the eyelids. Treatment is supportive with an individual approach to antibiotic use in uncomplicated cases since it may shorten symptom duration, but is not without risks.

Janus-type emission from a cyclometalated iron(III) complex.

Although iron is a dream candidate to substitute noble metals in photoactive complexes, realization of emissive and photoactive iron compounds is demanding due to the fast deactivation of their charge-transfer states. Emissive iron compounds are scarce and dual emission has not been observed before. Here we report the Fe complex [Fe(ImP)][PF] (HImP = 1,1'-(1,3-phenylene)bis(3-methyl-1-imidazol-2-ylidene)), showing a Janus-type dual emission from ligand-to-metal charge transfer (LMCT)- and metal-to-ligand charge transfer (MLCT)-dominated states.

Higher MLCT lifetime of carbene iron(II) complexes by chelate ring expansion.

Combining strong σ-donating N-heterocyclic carbene ligands and π-accepting pyridine ligands with a high octahedricity in rigid iron(ii) complexes increases the 3MLCT lifetime from 0.15 ps in the prototypical [Fe(tpy)2]2+ complex to 9.2 ps in [Fe(dpmi)2]2+12+.

Ground- and Excited-State Properties of Iron(II) Complexes Linked to Organic Chromophores.

Two new bichromophoric complexes, [Fe(bim-ant)] and [Fe(bim-pyr)] ([H-bim] = 1,1'-(pyridine-2,6-diyl)bis(3-methyl-1-imidazol-3-ium); ant = 9-anthracenyl; pyr = 1-pyrenyl), are investigated to explore the possibility of tuning the excited-state behavior in photoactive iron(II) complexes to design substitutes for noble-metal compounds. The ground-state properties of both complexes are characterized thoroughly by electrochemical methods and optical absorption spectroscopy, complemented by time-dependent density functional theory calculations. The excited states are investigated by static and time-resolved luminescence and femtosecond transient absorption spectroscopy.

Vertebral Body Osteolysis 6 Years After Cervical Disk Arthroplasty.

Cervical arthroplasty is an accepted and widely performed surgical intervention with usually favorable outcomes. We report a rare case of a 37-year-old woman who presented with vertebral body osteolysis, 6 years after two-level cervical arthroplasty (C5-C6 and C6-C7). The patient showed no initial complications, but at year 6 she presented with neck and radicular arm pain.

Phase space methods for non-linear analysis of pedalling forces in cycling.

Introduction: From the perspective of dynamic systems theory, stability and variability of biological signals are both understood as a functional adaptation to variable environmental conditions. In the present study, we examined whether this theoretical perspective is applicable to the pedalling movement in cycling. Non-linear measures were applied to analyse pedalling forces with varying levels of subjective load.

Restoration of cellular integrity following "ballistic" pronuclear exchange during Tetrahymena conjugation.

During sexual reproduction or conjugation, ciliates form a specialized cell adhesion zone for the purpose of exchanging gametic pronuclei. Hundreds of individual membrane fusion events transform the adhesion zone into a perforated membrane curtain, the mating junction. Pronuclei from each mating partner are propelled through this fenestrated membrane junction by a web of short, cris-crossing microtubules.

Comparison of Near-Infrared Spectroscopy with Needle Indentation and Histology for the Determination of Cartilage Thickness in the Large Animal Model Sheep.

The suitability of near-infrared spectroscopy (NIRS) for non-destructive measurement of cartilage thickness was compared with the gold standard needle indentation. A combination of NIRS and biomechanical indentation (NIRS-B) was used to address the influence of varying loads routinely applied for hand-guided NIRS during real-life surgery on the accuracy of NIRS-based thickness prediction. NIRS-B was performed under three different loading conditions in 40 osteochondral cylinders from the load-bearing area of the medial and lateral femur condyle of 20 cadaver joints (left stifle joints; female Merino sheep; 6.

Risk of exercise-induced hypoglycaemia in patients with type 2 diabetes on intensive insulin therapy: comparison of insulin glargine with NPH insulin as basal insulin supplement.

Aim: Hypoglycaemia is the most common adverse event associated with intensive conventional insulin therapy (ICT). This study compared the risk of exercise-related hypoglycaemia in type 2 diabetes patients receiving either basal insulin glargine or NPH insulin.

Methods: In a prospective trial, 122 ICT patients (glargine n=60, NPH n=62) had a standardized treadmill test, monitored by capillary lactate concentration.

Stress echocardiography for risk stratification of asymptomatic patients with type 2 diabetes mellitus.

Background: The purpose of this study was to assess stressechocardiography (SE) for risk stratification of asymptomatic type 2 diabetic patients (DM2) without known coronary artery disease CAD.

Methods: A total of 211 consecutive, asymptomatic DM2 patients underwent exercise (n=177) or dobutamine (n=34) SE and were followed up for 11+/-2 months. Primary endpoint was a major cardiac or vascular event (MACCE; all-cause-death, non-fatal myocardial infarction, coronary revascularization procedures, cerebrovascular event, acute limb-ischemia).

Disseminated hyperkeratotic and granulomatous nodules in a child with fatal Epstein-Barr-virus-associated hemophagocytic lymphohistiocytosis.

Hemophagocytic lymphohistiocytosis is a rare and potentially fatal syndrome associated with a variety of genetic, malignant, autoimmune, or infectious conditions. The importance of cutaneous presentations of this syndrome has only recently been brought forward. We report the first case of Epstein-Barr-virus-associated hemophagocytic lymphohistiocytosis presenting with papulonodular and granulomatous skin lesions.

Platelet degranulation is associated with progression of intima-media thickness of the common carotid artery in patients with diabetes mellitus type 2.

Background: Platelets play a key role in atherogenesis and thromboembolic complications in patients with type 2 diabetes.

Methods And Results: We prospectively examined the relationship between systemic platelet activation and progression of carotid wall thickness within 1 year in 105 patients with type 2 diabetes. The intima-media thickness (IMT) of the common carotid artery was measured bilaterally at study entry and after 1 year.