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Porphyrins are vital pigments involved in biological energy transduction processes. Their abilities to absorb light, then convert it to energy, have raised the interest of using porphyrin nanoparticles as photosensitizers in photodynamic therapy. A recent study showed that self- assembled porphyrin-silica composite nanoparticles can selectively destroy tumor cells, but detection of the cellular uptake of porphyrin-silica composite nanoparticles was limited to imaging microscopy. Here we developed a novel method to rapidly identify porphyrin-silica composite nanoparticles using Atmospheric Solids Analysis Probe-Mass Spectrometry (ASAP-MS). ASAP-MS can directly analyze complex mixtures without the need for sample preparation. Porphyrin-silica composite nanoparticles were vaporized using heated nitrogen desolvation gas, and their thermo-profiles were examined to identify distinct mass- to-charge (M/Z) signatures. HeLa cells were incubated in growth media containing the nanoparticles, and after sufficient washing to remove residual nanoparticles, the cell suspension was loaded onto the end of ASAP glass capillary probe. Upon heating, HeLa cells were degraded and porphyrin-silica composite nanoparticles were released. Vaporized nanoparticles were ionized and detected by MS. The cellular uptake of porphyrin-silica composite nanoparticles was identified using this ASAP-MS method.
Mental disorder is common among individuals with neurological illness. We aimed to characterise the patient population referred for psychiatry assessment at a tertiary neurology service in terms of neurological and psychiatric diagnoses and interventions provided.
We studied all individuals referred for psychiatry assessment at a tertiary neurology service over a 2-year period (n= 82).
The most common neurological diagnoses among those referred were epilepsy (16%), Parkinson’s disease (15%) and multiple sclerosis (8%). The most common reasons for psychiatric assessment were low mood or anxiety (48%) and medically unexplained symptoms or apparent functional or psychogenic disease (21%). The most common diagnoses among those with mental disorder were mood disorders (62%), and neurotic, stress-related and somatoform disorders, including dissociative (conversion) disorders (28%). Psychiatric diagnosis was not related to gender, neurological diagnosis or psychiatric history.
Individuals with neurological illness demonstrate significant symptoms of a range of mental disorders. There is a need for further research into the characteristics and distribution of mental disorder in individuals with neurological illness, and for the enhancement of integrated psychiatric and neurological services to address the comorbidities demonstrated in this population.
The Australian Square Kilometre Array Pathfinder (ASKAP) will give us an unprecedented opportunity to investigate the transient sky at radio wavelengths. In this paper we present VAST, an ASKAP survey for Variables and Slow Transients. VAST will exploit the wide-field survey capabilities of ASKAP to enable the discovery and investigation of variable and transient phenomena from the local to the cosmological, including flare stars, intermittent pulsars, X-ray binaries, magnetars, extreme scattering events, interstellar scintillation, radio supernovae, and orphan afterglows of gamma-ray bursts. In addition, it will allow us to probe unexplored regions of parameter space where new classes of transient sources may be detected. In this paper we review the known radio transient and variable populations and the current results from blind radio surveys. We outline a comprehensive program based on a multi-tiered survey strategy to characterise the radio transient sky through detection and monitoring of transient and variable sources on the ASKAP imaging timescales of 5 s and greater. We also present an analysis of the expected source populations that we will be able to detect with VAST.
No U.S. general population-based study has characterized the epidemiology and risk factors, including skin and soft tissue infection (SSTI), for healthcare-associated (HA) and community-associated (CA) methicillin-resistant Staphylococcus aureus (MRSA). We estimated the incidence of HA- and CA-MRSA and SSTI over a 9-year period using electronic health record data from the Geisinger Clinic in Pennsylvania. MRSA cases were frequency-matched to SSTI cases and controls in a nested case-control analysis. Logistic regression was used to assess risk factors, while accounting for antibiotic administration. We identified 1713 incident CA- and 1506 HA-MRSA cases and 78 216 SSTI cases. On average, from 2005 to 2009, the annual incidence of CA-MRSA increased by 34%, HA-MRSA by 7%, and SSTI by 4%. Age, season, community socioeconomic deprivation, obesity, smoking, previous SSTI, and antibiotic administration were identified as independent risk factors for CA-MRSA.
To determine whether copper incorporated into hospital ward furnishings and equipment can reduce their surface microbial load.
A crossover study.
Acute care medical ward with 19 beds at a large university hospital.
Fourteen types of frequent-touch items made of copper alloy were installed in various locations on an acute care medical ward. These included door handles and push plates, toilet seats and flush handles, grab rails, light switches and pull cord toggles, sockets, overbed tables, dressing trolleys, commodes, taps, and sink fittings. Their surfaces and those of equivalent standard items on the same ward were sampled once weekly for 24 weeks. The copper and standard items were switched over after 12 weeks of sampling to reduce bias in usage patterns. The total aerobic microbial counts and the presence of indicator microorganisms were determined.
Eight of the 14 copper item types had microbial counts on their surfaces that were significantly lower than counts on standard materials. The other 6 copper item types had reduced microbial numbers on their surfaces, compared with microbial counts on standard items, but the reduction did not reach statistical significance. Indicator microorganisms were recovered from both types of surfaces; however, significantly fewer copper surfaces were contaminated with vancomycin-resistant enterococci, methicillin-susceptible Staphylococcus aureus, and coliforms, compared with standard surfaces.
Copper alloys (greater than or equal to 58% copper), when incorporated into various hospital furnishings and fittings, reduce the surface microorganisms. The use of copper in combination with optimal infection-prevention strategies may therefore further reduce the risk that patients will acquire infection in healthcare environments.
This study focuses on the association between language skills and core cognitive processes relative to the duration of institutionalization in children adopted from orphanages abroad. Participants in the adoptive group (n = 46) had arrived in the United States between the ages of 2 and 84 months (mean = 24 months), and had been living in the United States for 1–9 years. Drawing on both experimental and standardized assessments, language skills of the international adoptees differed as a function of length of time spent in an institution and from those of 24 nonadopted controls. Top-down cognitive assessments including measures of explicit memory and cognitive control differed between adopted and nonadopted children, yet differences between groups in bottom-up implicit learning processes were unremarkable. Based on the present findings, we propose a speculative model linking language and cognitive changes to underlying neural circuitry alterations that reflect the impact of chronic stress, due to adoptees' experience of noncontingent, nonindividualized caregiving. Thus, the present study provides support for a relationship between domain-general cognitive processes and language acquisition, and describes a potential mechanism by which language skills are affected by institutionalization.
To assess the general health and activity levels of 4- and 5-year-old children after intervention for congenital cardiac disease.
Health behaviour outcomes were assessed in 91 children who had surgery or catheter intervention for congenital cardiac disease. The children were classified into four groups according to severity. The main parameters of classification were the presence of residual symptoms, frequency of visits to general practitioner or the Accident and Emergency Department, and ability to participate in physical activity according to a calculated “activity score”.
Children had very few residual symptoms after “corrective surgery”. Those with complex congenital cardiac disease post-Fontan-type repair still had symptoms on average 18.2 days per month. Surprisingly, the complex group had fewer days “sick” from non-cardiac causes and had fewer visits to general practitioner or Accident and Emergency Departments. Regression analysis indicates that three variables had significant relevance to the general practitioner or Accident and Emergency visits: complex congenital cardiac disease, fewer visits; Townsend score – more deprivation – more visits; and maternal worry – higher maternal worry score – more visits. Regression analysis indicates that lower activity score is significantly related to complex cardiac disease and higher maternal worry score.
The majority of this group of 4- and 5-year-old children had few residual symptoms and had good exercise tolerance. Maternal worry is a significant factor in influencing both activity levels and frequency of unscheduled health service demands – general practitioner or Accident and Emergency visits.
Nb-silicide based in-situ composites are promising materials for future high-temperature structural applications. Nb-silicide composites are typically alloyed with Hf, Ti, Cr, and Al to provide a balance of mechanical and environmental properties. A thermodynamic description of the Nb-Cr-Si system has been developed previously in literature based on reported isothermal sections. According to the previously calculated phase diagrams, selected alloys were directionally solidified. The as-solidified microstructures could not be interpreted using the liquidus projection calculated from the existing thermodynamic descriptions. Therefore, an improved thermodynamic description was developed by incorporating the new experimental data.
Attention-deficit/hyperactivity disorder (ADHD) is a behavioral
syndrome that arises in early childhood, often co-occurs with conduct
disorder and leads, developmentally, to antisocial behavior and substance
abuse. Models from cognitive and affective neuroscience have been invoked
in an effort to understand the development of ADHD, leading to a broad
array of interrelated theories and hypothesized mechanisms. In this paper,
we highlight core mechanisms that may cut across several theories and
constructs, and thus provide some leverage for further study and
conceptualization from a neuroscience perspective. We emphasize the joint
operations of frontostriatal and frontocerebellar neural loops in
detecting and predicting what and when important events
in the environment will occur and their interaction with frontoamygdala
loops in assigning emotional significance to these events. We note that
weaknesses in the development of these basic operations could lead to
decrement in the development of cognitive and affective control and other
mental operations mediated by prefrontal cortex during development. In
turn, such decrement could lead to many of the phenotypic cognitive and
neuropsychological features seen in children with ADHD.This work was supported by National Institute of Mental Health
Grants R01-MH59105 and R01-MH63146 to J.T.N. and NIMH R01 MH63255 and NIDA
R21 DA15882 to B.J.C.
Three fundamentally different methods were used to fabricate nanometric surface features on polymers or fused silica. Phase separation of binary polymer mixes resulted in randomly distributed features whose depth and shape could be tightly controlled over large areas. Colloidal resist patterned large areas randomly and uniformly with very fine spikes. In contrast e-beam and reactive ion etching were used to create a set of regular spaced pillars on an orthogonal pattern. Some of the surfaces were replicated by in situ polymerization, solvent casting, embossing or melt molding onto polystyrene (PS) or ε–poly caprolactone (ε–PCL). Nanometric features down to 60nm were imprinted onto the polymers with high fidelity. Cells were seeded onto the nanometric surfaces and adhesion, morphology and cytoskeleton investigated. Cells respond to regular features of 170/80nm (width/depth) with reduced adhesion and changes in overall morphology and cytoskeleton. Small nanofeatures (13nm, 35nm depth) made by phase separation on the other hand increased adhesion and promoted cytoskeletal differentiation. The responses of the cells are indicative that nanometric surface features are useful modifications on scaffolds for tissue engineering or on medical implants.