Correction: Charge-tunnelling and self-trapping: common origins for blinking, grey-state emission and photoluminescence enhancement in semiconductor quantum dots.

Correction for 'Charge-tunnelling and self-trapping: common origins for blinking, grey-state emission and photoluminescence enhancement in semiconductor quantum dots' by M. A. Osborne, et al., Nanoscale, 2016, 8, 9272-9283.

Charge-tunnelling and self-trapping: common origins for blinking, grey-state emission and photoluminescence enhancement in semiconductor quantum dots.

Understanding instabilities in the photoluminescence (PL) from light emitting materials is crucial to optimizing their performance for different applications. Semiconductor quantum dots (QDs) offer bright, size tunable emission, properties that are now being exploited in a broad range of developing technologies from displays and solar cells to biomaging and optical storage. However, instabilities such as photoluminescence intermittency, enhancement and bleaching of emission in these materials can be detrimental to their utility. Here, we report dielectric dependent blinking, intensity-"spikes" and low-level, "grey"-state emission, as well as PL enhancement in ZnS capped CdSe QDs; observations that we found consistent with a charge-tunnelling and self-trapping (CTST) description of exciton-dynamics on the QD-host system. In particular, modulation of PL in grey-states and PL enhancement are found to have a common origin in the equilibrium between exciton charge carrier core and surface-states within the CTST framework. Parameterized in terms of size and electrostatic properties of the QD and its nanoenvironment, the CTST offers predictive insight into exciton-dynamics in these nanomaterials.

Dynamic symmetry-breaking in a simple quantum model of magneto-electric rectification, optical magnetization, and harmonic generation.

The state mixings necessary to mediate three new optical nonlinearities are shown to arise simultaneously and automatically in a 2-level atom with an ℓ = 0 ground state and an ℓ = 1 excited state that undergoes a sequence of electric and magnetic dipole-allowed transitions. The treatment is based on an extension of dressed state theory that includes quantized electric and magnetic field interactions. Magneto-electric rectification, transverse magnetization, and second-harmonic generation are shown to constitute a family of nonlinear effects that can take place regardless of whether inversion is a symmetry of the initial unperturbed system or not. Interactions driven jointly by the optical electric and magnetic fields produce dynamic symmetry-breaking that accounts for the frequency, the intensity dependence, and the polarization of induced magnetization in prior experiments. This strong field quantum model explains not only how a driven 2-level system may develop nonlinear dipole moments that are forbidden between or within its stationary states, but it also broadens the class of materials suitable for optical energy conversion applications and magnetic field generation with light so as to include all transparent dielectrics.

Serum leptin levels in older patients with hip fracture--impact on peri-operative myocardial injury.

To evaluate whether there is a relationship between admission serum leptin concentrations and peri-operative myocardial injury, 238 consecutive older patients (mean age 81.9+/-7.9 years; 172 women) with low-trauma hip fracture were assessed. Myocardial injury as defined by elevated serum cardiac troponin I was associated with lower leptin levels analyzed as continuous or categorical variables. Patients with serum leptin concentrations <12ng/ml (medium value) had a two-fold greater increased risk for such complications compared with those with higher leptin levels (odd ratio 2.13, 95% confidence interval 1.06-4.28; p=0.033). This association remained significant after adjustments for age, gender, clinical (history of coronary artery disease [CAD], stroke, hypertension, diabetes, dementia), hematological (red, white, and lymphocyte count, hemoglobin, hematocrit), metabolic (parathyroid hormone [PTH], albumin), renal(creatinine, urea, glomerular filtration rate [GFR]), and inflammatory (C-reactive protein [CRP], ferritin) factors. The predictive value of lower leptin levels increased significantly when used in combination with traditional risk factors for myocardial injury.

Trends in hip fracture epidemiology in Australia: possible impact of bisphosphonates and hormone replacement therapy.

The purposes of this study were to analyse trends in hip fracture (HF) epidemiology over a 13-year period (1994-2007) in the Australian Capital Territory (ACT), to assess the potential impact of concurrent changes in hormone replacement therapy (HRT) and bisphosphonate use and to present a new prediction of HFs in Australia up to 2021. Annual sex- and age-specific incidence rates (per 100,000 population) were determined and standardized using the Australian 2006 population. The projected number of HFs was estimated by two models applying age- and sex-specific HF rates averaged for 2002-2006 (model 1) or continuously changing as observed in this period (model 2, Poisson regression) to the projected population. In 2006 compared to 2001, the population > or = 60 years in the ACT increased by 19.7%. Over the last 5 years the average annual incidence HF rate compared to the previous 3-year period decreased in females > or = 60 years of age by 28.3%. Between 2001 and 2006 the number of prescriptions for HRT dispensed in the ACT declined by 54.6, while the number of prescriptions for bisphosphonate increased by 245%, accompanied by a decline in standardized incidence of HF rates of 36.4%, mainly in women (42.1%). This represents an annual cost for bisphosphonates per one prevented HF, of $A45,250 or $A576 person/year. Compared to 2006 the total number of HFs in Australia according to model 1 will increase in 2011 by 20.1% and in 2021 by 58.8%, but according to model 2 will decrease by 15.5% in 2011 and 27.5% in 2021. Our data suggest that the previously predicted rising trend in HFs in elderly women reversed, but did not so for men. This was coincident with a significant fall in HRT use and increased prescribing of bisphosphonates, which is cost-effective. However caution should be used in attributing causation as this is an ecological study. If trends in HF observed in 2002-2006 continue, the absolute number of HFs in Australia in 2011-2021 will stabilise or decline (which is more likely), despite the rapid ageing of the population.

Elevated serum cardiac troponin I in older patients with hip fracture: incidence and prognostic significance.

INTRODUCTION: Cardiovascular complications are the main causes of morbidity and mortality in patients with osteoporotic hip fracture (HF). The aim of this prospective study was to evaluate the incidence and prognostic significance of elevated cardiac troponin I (cTnI) in the early peri-operative period in older patients with HF. MATERIALS AND METHODS: A blind evaluation of myocardial injury as detected by cTnI elevation in 238 consecutive older patients with low-trauma HF (mean age 81.9 +/- 7.8 (SD) years; 72% females). Data on demographic and clinical characteristics, in-hospital mortality, hospital length of stay and discharge destination were collected prospectively. Serum cTnI level was analysed from blood collected routinely in the first 72 h of hospital admission. RESULTS: Sixty-nine (29%) patients had elevated cTnI (>0.06 microg/l) but myocardial injury was clinically recognised in only 23 (33%) and only 24 (34.8%) had a history of coronary artery disease (CAD). Patients with elevated cTnI were significantly older, more often had American Society of Anaesthesiologist status score >or=3, a history of CAD or stroke and more often were current smokers than the patients without cTnI elevation. In multivariate regression analysis only age was an independent predictor of cTnI elevation. Patients with cTnI release were twice as likely to have a length of stay >or=20 days (P = 0.047) and 2.7 times more likely to be discharged to a long-term residential care facility (RCF) (P = 0.013). cTnI level >or=1 microg/l was a strong independent predictor of all-cause mortality with 98.3% specificity and 89.1% negative predictive value. CONCLUSION: Peri-operative myocardial injury is common in older HF patients but is frequently unrecognised clinically. Elevated blood cTnI level is an independent predictor of prolonged length of hospital stay (>or=20 days), need for long-term RCF and mortality (if cTnI >or=1 microg/l).

Outcomes for older patients with hip fractures: the impact of orthopedic and geriatric medicine cocare.

OBJECTIVES: To assess the impact of a specifically designed model of orthopedic-geriatric cocare on hip fracture (HF) outcomes. SETTING: Tertiary teaching hospital (level I trauma center). DESIGN: Prospective observational study with a retrospective (historical) control. Data on 951 consecutive patients 60 years of age or older admitted to the authors' institution with a nonpathologic HF over a 7-year period (1995 to 2002) were analyzed. Between 1995 and 1997, medical problems were managed by a geriatric medicine (GM) consultation-only service (retrospective audit). In 1998, a GM registrar began overseeing daily medical care with weekly geriatrician consultant review (prospective study). Outcomes for 2 time periods were compared: a 3-year period before (no GM; 504 patients) and a 4-year period after (GM; 447 patients) the introduction of GM cocare. MAIN OUTCOME MEASUREMENTS: Postoperative medical complications, mortality, length of stay, discharge destination, use of thromboprophylaxis, and antiosteoporotic treatment. RESULTS: While comparing 2 periods (GM and no GM), significant reductions in postoperative medical complications and comorbid conditions (in total 49.5% vs. 71.0%, P<0.001) and mortality (4.7% vs. 7.7%, P<0.01) occurred and rehospitalization to medical wards within 6 months decreased (28% vs. 7.6%). However, no differences were observed in median length of hospital stay (10.8 vs. 11.0 days) or in discharge destination. Antiosteoporotic treatment (12% to 69%) and specific thromboprophylaxis (63% to 94%) increased in the GM period. CONCLUSIONS: Orthopedic-geriatric cocare for the older patients with HF was associated with significant reductions in morbidity and mortality, and increases in optimal postoperative care. Options for further improvement of orthopedic-GM cocare need to be investigated.

Nephrotoxicity and hepatotoxicity of histamine H2 receptor antagonists.

The extensive use of selective histamine H2 receptor antagonists provides a unique opportunity to describe very rare adverse drug reactions. Although mild elevation of serum creatinine level following the administration of cimetidine is relatively common, acute interstitial nephritis (AIN) is a rare hypersensitivity reaction. There have been 25 published reports of AIN associated with H2 antagonist therapy and we also identified 16 cases from the Australian Adverse Drug Reaction Advisory Committee (ADRAC) database. AIN was reported most commonly following cimetidine administration. AIN was supported by renal biopsy in 28 patients and by rechallenge in 6. H2 antagonist-induced AIN was more commonly reported in men older than 50 years. In the majority of cases the onset was within 2 weeks of initiation of therapy (1 day to 11 months). The clinical manifestations were nonspecific including sterile pyuria, elevated erythrocyte sedimentation rate, fatigue, proteinuria and leucocytosis whereas rash, arthralgia and flank pain were rarely reported. There were 170 cases of hepatotoxicity following H2 antagonist administration reported to ADRAC. These were more common following ranitidine and included cholestatic, hepatocellular and mixed reactions. Hepatotoxicity was proven following liver biopsy in several cases published in the literature and in 15 cases reported to ADRAC. Hepatotoxicity recurred upon rechallenge in 6 cases. Generally, renal and hepatic adverse effects resolved quickly after cessation of H2 antagonist therapy and did not require specific treatment. Nephrotoxicity and hepatotoxicity following administration of an H2 antagonist is rare and a high index of suspicion is necessary for early detection. Now that many H2 antagonists are available over the counter, awareness of these conditions and early detection with cessation of H2 antagonist therapy would appear paramount.

Intracerebral hemorrhage following possible interaction between celecoxib and clopidogrel.

OBJECTIVE: To report a case of intracerebral hemorrhage following short-term, concomitant use of celecoxib and clopidogrel. CASE SUMMARY: An 86-year-old white woman with a medical history of paroxysmal atrial fibrillation, heart failure, osteoarthritis, peptic ulcer disease, chronic airway limitation, and surgery for carcinoma of the bowel and breast began clopidogrel therapy following a syncopal episode. She also began taking celecoxib for osteoarthritis at the same time. Three weeks later, she presented with headaches and left hemiparesis. Computed tomography scan revealed intracerebral hemorrhage that had not been previously detected. Celecoxib and clopidogrel were discontinued, and she recovered fully. DISCUSSION: This is the first case describing a possible interaction between celecoxib and clopidogrel. A pharmacokinetic interaction mediated by CYP2C9 is possible. However, the hemorrhage may have been secondary to the effects of either drug alone or concomitant disease. CONCLUSIONS: Celecoxib and clopidogrel have favorable risk profiles and, therefore, are prescribed widely among older people. However, clinicians should recognize that there may be an interaction between celecoxib and clopidogrel that increases the risk of hemorrhage in older people.

Lead poisoning from complementary and alternative medicine in multiple sclerosis.

A patient with multiple sclerosis is described who was treated for neurological symptoms thought to be a progression of his disease but subsequently found to be caused by lead poisoning secondary to the use of alternative medicine. His clinical signs improved with oral chelation therapy. Neurologists should consider asking about the use of complementary and alternative medicine before simply attributing symptoms and signs to exacerbation of multiple sclerosis.

Toxicity of Passiflora incarnata L.

BACKGROUND: Herbal medicines may have significant adverse effects which are not suspected or recognized. CASE REPORT: A 34-year-old female developed severe nausea, vomiting, drowsiness, prolonged QTc, and episodes of nonsustained ventricular tachycardia following self-administration of a herbal remedy, Passiflora incarnata L., at therapeutic doses. The possible association of symptoms with passiflora was not recognized for several days. She required hospital admission for cardiac monitoring and intravenous fluid therapy. CONCLUSIONS: Passiflora incarnata was associated with significant adverse effects in this patient. It is important to ask specifically about the use of herbal medicines in patients with undiagnosed illnesses.