Highly oriented single-crystalline gold quantum-dot metamaterials as prospective materials for photonics.

Miniaturization of optical devices is a modern trend essential for optoelectronics, optical sensing, optical computing and other branches of science and technology. To satisfy this trend, optical materials with a small footprint are required. Here we show that extremely thin, flat, nanostructured gold films made of highly oriented single-crystalline gold quantum-dots can provide elements of topological photonics in visible light and be used as high-index dielectric materials in the infrared part of the spectra. We measure and theoretically confirm the presence of topological darkness and associated phase singularities in studied gold films of thickness of below 10 nm placed on MgO substrates in the red part of the spectrum. At telecom wavelengths, the fabricated gold metasurface behaves as a dielectric with the refractive index of n≈2.75 and the absorption coefficient of k≈0.005.

Band-offsets scaling of low-index Ge/native-oxide heterostructures.

We investigate, through XPS and AFM, the pseudo layer-by-layer growth of Ge native oxide across Ge(001), (110) and (111) surfaces in ambient environment. More significantly, our study reveals a universal set of valence and conduction band offset (VBO and CBO) values observed for Ge(001), Ge(110), and Ge(111) surfaces as a function of Ge-oxide concentration. We find that the band offsets appear to be the same across these low-index Ge surfaces i.e., for Ge-oxide/Ge heterostructures with the same Ge-oxide overlayer concentration or thickness. In contrast, different oxidation rates for Ge(001), Ge(110), and Ge(111) surfaces were observed, where the oxidation rate is fastest for Ge(001), compared to Ge(110) and Ge(111). This can be attributed to the different number of unsatisfied Ge dangling bonds (2 vs 1) associated to the respective ideal Ge surface in forming Ge-oxide. Thus, at any given oxidation time, the oxide concentration or thickness for each type of low index Ge surface will be different. This in turn will lead to different band offset value observed for each type of Ge surface. More significantly, we show that while oxidation rates can differ from different Ge surface-types, the band offset values can be estimated simply based on the Ge-oxide concentration regardless of Ge surface type.

Recurrent Cellulitis: Who is at Risk and How Effective is Antibiotic Prophylaxis?

Recurrent cellulitis following successful treatment is common and prevention should be a major component in the management of cellulitis. Conditions that increase the risk of recurrence include chronic edema, venous disease, dermatomycosis and obesity. These risk factors should be actively managed as further episodes of cellulitis increases the risk of recurrence. The role of non-antibiotic measures is important and should be first-line in prevention. Antibiotic prophylaxis is effective, but its role is limited to non-purulent cellulitis where risk factors are appropriately managed.

A New Spin-Correlated Plasmon in Novel Highly Oriented Single-Crystalline Gold Quantum Dots.

A concept of spin plasmon, a collective mode of spin-density, in strongly correlated electron systems has been proposed since the 1930s. It is expected to bridge between spintronics and plasmonics by strongly confining the photon energy in the subwavelength scale within single magnetic-domain to enable further miniaturizing devices. However, spin plasmon in strongly correlated electron systems is yet to be realized. Herein, we present a new spin correlated-plasmon at room temperature in novel Mott-like insulating highly oriented single-crystalline gold quantum-dots (HOSG-QDs). Interestingly, the spin correlated-plasmon is tunable from the infrared to visible, accompanied by spectral weight transfer yielding a large quantum absorption midgap state, disappearance of low-energy Drude response, and transparency. Supported with theoretical calculations, it occurs due to an interplay of surprisingly strong electron-electron correlations, s-p hybridization and quantum confinement in the s band. The first demonstration of the high sensitivity of spin correlated-plasmon in surface-enhanced Raman spectroscopy is also presented.

Pulmonary embolism: clinical presentation and diagnosis in the oldest old.

The incidence of pulmonary embolism (PE) in the oldest old (persons aged ≥85) is increasing, but there are limited data on its clinical features and diagnosis. We performed a retrospective cohort study of 302 consecutive patients with confirmed PE and compared the oldest old to the young (aged <65) and the younger old (aged 65-84). The most common symptoms in the oldest old were dyspnoea (74.3%) and tachypnoea (71.4%), but the prevalence of chest pain decreased with advancing age. Delayed diagnosis was most common in the oldest old and was associated with increasing age, absence of dyspnoea, presence of cardiorespiratory disease and a higher Charlson Comorbidity index. Better age-specific diagnostic pathways are required in this population.

Optical constants and absorption properties of Te and TeO thin films in the 13-14†nm spectral range.

Undesired mask-induced effects caused by thick absorber layers in EUV photomasks reduce the quality of the projected patterns at the wafer stage in EUV photolithography scanners. New materials with better absorption properties than the state-of-the-art absorbers, TaN and TaBN, are required to mitigate these effects. In this work, we investigated the optical properties (δ and k) of Te and TeO films in the 13-14 nm range, and the absorption properties of these two materials at 13.5 nm. δ and k are obtained through fitting experimental values of reflectivity versus angle of incidence in the EUV range. We follow a methodology which combines different characterization techniques (X-ray reflectivity, EUV reflectivity, and X-ray photoemission spectroscopy) to reduce the number of free parameters in models and hence, increase the reliability of the optical constants obtained. At 13.5 nm, we obtain δ=0.03120, k = 0.07338 for Te, and δ=0.04099, k = 0.06555 for TeO. To experimentally verify the absorption properties of these materials, different thicknesses of Te and TeO films are cast on top of a state-of-the-art mask-quality EUV multilayer with 66.7% reflectivity at 13.5 nm. We found that a reflectivity of ∼0.7% can be attained with either 32.4 nm of Te, or 34.7 nm of TeO, greatly surpassing the absorption properties of TaN and TaBN. The morphology and surface roughness of the Te and TeO films deposited on the multilayer are also investigated.

Cellulitis in older people over 75 years - are there differences?

AIM: To examine differences in risk factors, clinical features and outcomes of cellulitis between those 75 + years and those <75 years admitted to a metropolitan hospital. METHODS: A prospective study of patients with limb cellulitis requiring intravenous antibiotics conducted at Bankstown-Lidcombe Hospital, Australia from June 2014 to April 2015. RESULTS: Thirty one patients were 75 + years and 69 less than 75 years. A greater proportion of older patients resided in nursing home (25.8% vs 2.9% respectively, p = 0.001) and mobilized with walking aid(s) (58.1% vs 11.6% respectively, p < 0.001). Significantly more older patients had documented hypertension (45.2% vs 23.2% respectively p = 0.035), atrial fibrillation (33.5% vs 5.8% respectively, p < 0.001), dementia (22.6% vs 1.4% respectively, p = 0.001) and malignancy (16.1% vs 1.4% respectively, p = 0.010). The clinical presentation of cellulitis and cellulitis severity (Eron classification) did not significantly differ in both groups; however older patients were more likely to have dependent edema (OR 4.0, 95%CI 1.3-12.6, p = 0.018) and less likely to be obese (OR 0.3, 95%CI 0.1-0.8, p = 0.012) or had a past history of cellulitis (OR 0.3, 95%CI 0.1-1.0, p = 0.044) on presentation. Despite the age difference, there were no major differences in intravenous antibiotic choice, hospital length of stay, and hospital readmission rates in both groups. Older patients however, were more likely to experience complications such as falls and/or decreased mobility (38.7% vs 15.9% respectively, p = 0.020) during the cellulitis episode. CONCLUSION: There are minor differences in the risk factors and clinical features of cellulitis in older patients as compared to the young. Outcomes are similar except for a higher incidence of hospital related complications.

Out Of Hospital And In Hospital Management Of Cellulitis Requiring Intravenous Therapy.

BACKGROUND: Cellulitis requiring intravenous therapy can be managed via out of hospital programs, but a high number of patients are still admitted to hospital. OBJECTIVE: We aimed to review the clinical features, management and outcomes of patients with cellulitis requiring intravenous therapy in a Hospital in the Home (HITH) program compared to patients who are admitted to hospital. METHODS: A prospective cohort study of patients with limb cellulitis requiring intravenous antibiotics was conducted at a metropolitan principal referral hospital. RESULTS: A total of 100 patients out of 113 eligible patients were recruited. Forty-eight were treated entirely in hospital and 52 were treated entirely or partially via HITH. Patients treated in hospital were older (mean 69.2 vs 56.7 years, p<0.001), less mobile, have more comorbidities (Charlson Comorbidity Index mean 2.2 vs 1.2, P=0.005) and more associated active illness. All patients with Eron Class III were admitted to hospital. Patients treated in hospital had a higher incidence of acute renal failure (27.1% vs 3.8%, p=0.001), nosocomial infection (10.4% vs 0.0%, P=0.023), and a higher 28-day hospital readmission rate (10.4% vs 0.0%, P=0.023). CONCLUSION: Approximately half of the patients who require intravenous therapy can be treated via an out of hospital program. Patients admitted to hospital were more unwell and more likely to suffer complications. The presence of comorbid illness does not necessarily exclude participation in HITH and careful selection is essential to ensure safe outcomes.

Medical Assessment Units and the older patient: a retrospective case-control study.

OBJECTIVE: To evaluate the effect of a Medical Assessment Unit (MAU) on older patients. METHODS: Retrospective case-control study of patients 65 years and above admitted to the MAU (study group) and the general medical wards (control group) in Bankstown-Lidcombe Hospital from 1 October 2008 to 31 March 2009 with four most common Diagnosis-Related Groups (DRG) ('falls and gait disorder', 'chronic obstructive pulmonary disease (COPD)', 'other major respiratory diseases and 'cellulitis'). MAIN OUTCOME MEASURES: Length of stay (LOS) in Emergency Department (ED) and in the hospital, mortality, readmissions within 1 month, and discharge destination. RESULTS: Eighty-nine patients were studied; 47 in the MAU group and 42 in the non-MAU group. The MAU cohort was significantly older (84.1 ± 7.9 years v. 80.4 ± 7.8 years, respectively, P=0.03); and had shorter ED LOS (4.9 ± 3.0h v. 6.5 ± 2.8h, P=0.012). Overall hospital LOS did not differ except for patients with 'cellulitis', (5.7 ± 4.9 days for MAU cohort v. 14.8 ± 6.8 days for non-MAU cohort, P=0.022). There was no significant difference in mortality, readmission rate or discharge destination. Conclusions. The MAU can be an effective service model for older patients. More research is required to confirm this and to define the key elements that are essential for its effectiveness.

Management and outcomes of delirious patients with hyperactive symptoms in a secured behavioral unit jointly used by geriatricians and pyschogeriatricians.

To compare the clinical outcomes and length of stay (LOS) between delirious patients with hyperactive symptoms admitted directly and those admitted indirectly from Emergency Department into a secured, behavioral unit jointly used by geriatricians and pyschogeriatricians (the Unit). A retrospective study analyzing data from the medical records of 122 patients with an admission diagnosis of delirium with hyperactive symptoms and subsequently discharged from the Unit, including restraint, one-to-one nursing care, falls, absconding, duration of delirium, recovery from delirium, destination and LOS. Significantly fewer patients with direct admission (n=68) required physical restraint or chemical restraint compared with those transferred (n=54). Patients admitted directly showed a higher discharge rate back home, shorter LOS, shorter duration of delirium and a higher rate of recovery from delirium than transferred patients. Of the transferred patients, more received one-to-one nursing care before transfer than after transfer. Three (5.6%) absconded before transfer, but none absconded from the Unit. The falls rate reduced from 14.2 to 6.7 falls/1000 patient delirium days after transfer. Delirious patients with hyperactive symptoms admitted directly to the Unit fared better in clinical outcomes and LOS. They also required less restraint, less intensive nursing and were unlikely to abscond compared to those transferred.

Serum C-reactive protein as a biomarker for early detection of bacterial infection in the older patient.

BACKGROUND: although C-reactive protein (CRP) is widely used in younger populations, its value for diagnosing bacterial infection in older population is not well established. This study examined the usefulness of serum CRP level in the early detection of bacterial infection in older patients. METHODS: in a prospective cohort study, consecutive patients aged 70 years or over admitted to Aged Care wards were recruited. CRP levels were measured within 24 h of presentation, and their significance in predicting bacterial infections was analysed. The relationship between CRP and other clinical features of diagnosing bacterial infections (e.g. temperature, white cell count, neutrophil count, oxygen saturation, blood pressure and heart rate) was also examined. RESULTS: a total of 232 patients were recruited over a period of 3 months. CRP levels were 21.3 +/- 36.0 and 150.5 +/- 114.1 mg/l (mean +/- SD) in the non-infection and infection groups, respectively (P < 0.001). We found that the CRP cut-off value of 60 mg/l had the best combination of sensitivity and specificity. At this level, the sensitivity of diagnosing bacterial infection was 80.7%, specificity 96.0%, positive predictive value 91.9% and negative predictive value 89.8%. CRP and temperature had higher sensitivity and specificity than white cell count and neutrophil count in the diagnosis of infection. For every 1-mg/l increment in CRP, the risk of bacterial infection increases by 2.9%. CONCLUSION: CRP is a convenient and useful biomarker to predict early bacterial infection in older patients especially when other markers are atypical or not present.

Dysphagia: causes, assessment, treatment, and management.

Dysphagia, or difficulty in swallowing, is a condition with a strong age-related bias. Rates of dysphagia vary due to differences in method between studies; eg, clinical history of "swallowing difficulty," evidence of aspiration, or dysphagia confirmed by swallowing investigations. In general, the rate is lower in the community than in nursing home facilities. The management and treatment of dysphagia among geriatric patients is complicated by cognitive decline, lowered immunity, malnutrition, and end-of-life decisions. This article reviews the current assessment, treatment, and management techniques for dysphagia; covers new developments in research and pilot studies; and reviews the ethical issues related to treatment when prognosis is poor.

Safety and low molecular weight heparin in older people in a hospital with ambulatory care.

UNLABELLED: To examine major bleeding and mortality rates of low molecular weight heparin (LMWH) and unfractionated heparin (UFH) for patients with pulmonary embolism (PE) and/or deep vein thrombosis (DVT), a retrospective review of the medical records for 286 patients who presented at a local hospital with PE and/or DVT during the period November 2002-August 2003 was performed. DATA COLLECTED: presence of co-morbidities, concurrent medications, presence, site and severity of bleeding, outcome. Of all the patients, 50.7% received LMWH plus warfarin, 21.0% received UFH plus LMWH plus warfarin, 14.0% received UFH and warfarin, and 9.8% received LMWH only. There were nine minor bleeds and six major bleeds, which resulted in four deaths. Being a hospitalized patient and being age > or =70 years were associated with a major bleed (p<0.05). For hospital inpatients age > or =70 years on UFH and LMWH the number of major bleeds/1000 patient days was 18.9 and 9.2, respectively. The major bleeding rate is comparable if not better than that reported in the literature in our hospital setting where nearly half of the anticoagulation services were provided as ambulatory care. The increased rate of bleeding in the elderly we found is consistent with the findings of previous studies.

Management of pulmonary embolism in the home.

AIM: To describe the characteristics, outcomes and treatment complications of patients with pulmonary embolism (PE) who were treated at home and as outpatients in an ambulatory care program. METHODS: Retrospective descriptive study of patients with PE who were treated in the ambulatory care unit during 2003. Ambulatory care unit data and medical record information were reviewed. Data collected included demographic and clinical data, standard clinical indicators of unplanned admission during treatment program, incidence of major bleeding, recurrent venous thromboembolism (VTE), and death within 3 months of admission into the ambulatory care program. RESULTS: 130 patients with PE were treated: 46% were treated totally as outpatients and 54% as early discharge patients. Mean age was 66.4 years; 61% were women. The program was successfully completed for 89% of patients; one patient was lost to follow-up. There were three episodes of major bleeding (2%; 95% CI, 0.5%-7%), all in patients aged > 70 years. Four patients died (3%; 95% CI, 0.8%-8%) within 3 months of admission into the program, but none in the first week, no death being directly attributable to PE. There were seven episodes of recurrent VTE (5%; 95% CI, 2%-11%). CONCLUSION: Appropriately selected patients with sub-massive PE can be treated as outpatients and in the home. Although the outcome is good in most patients, a significant proportion will require admission, emphasising the need for a well defined protocol and close medical supervision. Further study will more closely define at-risk patients and refine the care pathways.

Hospitalisation, care plans and not for resuscitation orders in older people in the last year of life.

BACKGROUND: over 60% of older people have at least one admission to hospital in their last year of life, with the majority of people having multiple admissions. In Bankstown, New South Wales, Australia, we have a diverse ethnic and cultural population. We were interested in bed utilisation, documentation, and follow through of "care plans" as well as "not for resuscitation" orders in the last year of life of the older people in our area. METHODS: we reviewed and collected data from the medical records of patients over 65 years of age who died in our hospital. Reviewers included a medical registrar, a research officer and two geriatricians. We collected a wide range of information pertaining to the 12 months before death. This included demographics, chronic illnesses, geriatric syndromes, number of admissions, bed days, care plans, and not for resuscitation orders as well as other relevant data. RESULTS: 110 patients' records were reviewed. The mean age was 80 years and 31% were from a non English-speaking background. The average number of admissions was 2.4 and the average number of bed days in the last year of life was 25. Sixty-one of the patients had a care plan and a not for resuscitation order, 91% of which were written shortly before death. Using bi-variate analysis of old age (over 80), number of chronic illnesses, or geriatric syndromes present, the number of bed days was positively correlated to care plan and not for resuscitation orders. Logistic multivariate analysis of chronic illnesses revealed that stroke (P=0.024) as well as stroke and fracture (P=0.008) were strongly correlated with care plan and not for resuscitation orders. Only 8 patients had an advanced care plan documented prior to last admission. When advanced care plans were documented, they were generally clearly written and followed through appropriately (7 out of 8). CONCLUSION: this study showed that in our diverse population there were multiple admissions and utilisation of hospital beds for older people in their last year of life. Care plans and not for resuscitation orders were rarely documented prior to last admission. However, when advanced care plans were done, they were usually well documented and followed through appropriately.