Ribose Alters the Photochemical Properties of the Nucleobase in Thionated Nucleosides

Substitution of exocyclic oxygen with sulfur was shown to substantially influence the properties of RNA/DNA bases, which are crucial for prebiotic chemistry and photodynamic therapies. Upon UV irradiation, thionucleobases were shown to efficiently populate triplet excited states and can be involved in characteristic photochemistry or generation of singlet oxygen. Here, we show that the photochemistry of a thionucleobase can be considerably modified in a nucleoside, that is, by the presence of ribose. Our transient absorption spectroscopy experiments demonstrate that thiocytosine exhibits 5 times longer excited-state lifetime and different excited-state absorption features than thiocytidine. On the basis of accurate quantum chemical simulations, we assign these differences to the dominant population of a shorter-lived triplet nπ* state in the nucleoside and longer-lived triplet ππ* states in the nucleobase. This explains the distinctive photoanomerziation of thiocytidine and indicates that the nucleoside will be a less efficient phototherapeutic agent with regard to singlet oxygen generation.

Supporting advanced dementia in people with Down syndrome and other intellectual disability: consensus statement of the International Summit on Intellectual Disability and Dementia

BACKGROUND

The International Summit on Intellectual Disability and Dementia (Glasgow, Scotland; October 2016) noted that advanced dementia can be categorised as that stage of dementia progression characterised by significant losses in cognitive and physical function, including a high probability of further deterioration and leading to death.

METHOD

The question before the Summit was whether there were similarities and differences in expressions of advanced dementia between adults with intellectual disability (ID) and adults in the general population.

RESULTS

The Summit noted challenges in the staging of advanced dementia in people with ID with the criteria in measures designed to stage dementia in the general population heavily weighted on notable impairment in activities of daily living. For many people with an ID, there is already dependence in these domains generally related to the individuals pre-existing level of intellectual impairment, that is, totally unrelated to dementia. Hence, the Summit agreed that as was true in achieving diagnosis, it is also imperative in determining advanced dementia that change is measured from the person's prior functioning in combination with clinical impressions of continuing and marked decline and of increasing co-morbidity, including particular attention to late-onset epilepsy in people with Down syndrome. It was further noted that quality care planning must recognise the greater likelihood of physical symptoms, co-morbidities, immobility and neuropathological deterioration.

CONCLUSIONS

The Summit recommended an investment in research to more clearly identify measures of person-specific additional decline for ascertaining advanced dementia, inform practice guidelines to aid clinicians and service providers and identify specific markers that signal such additional decline and progression into advanced dementia among people with various levels of pre-existing intellectual impairment.

Ion selective transistor modelling for behavioural simulations

Computer aided design and simulation of complex silicon microsystems oriented for environment monitoring requires efficient and accurate models of ion selective sensors, compatible with the existing behavioural simulators. This paper concerns sensors based on the back-side contact Ion Sensitive Field Effect Transistors (ISFETs). The ISFETs with silicon nitride gate are sensitive to hydrogen ion concentration. When the transistor gate is additionally covered with a special ion selective membrane, selectivity to other than hydrogen ions can be achieved. Such sensors are especially suitable for flow analysis of solutions containing various ions. The problem of ion selective sensor modelling is illustrated here on a practical example of an ammonium sensitive membrane. The membrane is investigated in the presence of some interfering ions and appropriate selectivity coefficients are determined. Then, the model of the whole sensor is created and used in subsequent electrical simulations. Providing that appropriate selectivity coefficients are known, the proposed model is applicable for any membrane, and can be straightforwardly implemented for behavioural simulation of water monitoring microsystems. The model has been already applied in a real on-line water pollution monitoring system for detection of various contaminants.

Clinical relevance of hepatitis G virus (HGV) infection in heart transplant patients

To investigate whether the recently discovered hepatitis G virus (HGV) influences the clinical outcome of heart transplant recipients under immunosuppression, we determined the prevalence of HGV infections correlated with liver function and survival in 51 patients. Presence of HGV RNA and anti-E2, a marker for resolved HGV infection, were serially tested in sera from patients before and after heart transplantation (HTX) by nested RT-PCR and ELISA. Four of 51 (7.8%) patients before transplantation, and 22 of 50 patients (44%) after transplantation showed signs of persistent or resolved HGV infection. HGV infection was not associated with impairment of liver function or with patient survival. In summary, presence of HGV infection does not influence the clinical outcome in heart transplant patients.

Area agency on aging outreach and assistance for households with older carers of an adult with a developmental disability

A demonstration project was undertaken in the state of New York to assess how area agencies on aging (AAAs) would approach outreach and direct aid to families caring for someone with a developmental disability. It was found that AAAs organized their outreach and direct-aid efforts using three main approaches: direct operation, contract operations, and multi-organizational. They generally organized staff time so that about two days per week of effort was devoted to undertaking outreach activities, conducting community education, and providing casework and referrals for target families. Four major distinctions were identified that differentiated work with older carers of persons with a developmental disability from that with other kinds of carers: complexity of problems presented by households identified, vagaries of fiscal resources, diverse household composition, and planning for eventualities. It was concluded that targeting AAAs for outreach and providing help to these carers was effective and productive and should be replicated throughout the United States.

Determination of cobalt in vegetable animal foodstuffs by differential pulse adsorptive voltammetry using alpha-benzil dioxime

A selective and sensitive voltammetric method for the determination of cobalt in vegetable animal foodstuffs is developed. The method is based on the use of alpha-benzil dioxime (alpha-BD) as a chelating agent for differential pulse adsorptive stripping voltammetry (DPASV) and is free from zinc interferences. The influence of pH, time and alpha-BD concentration on the peak resolution and height are discussed. The method was successfully applied in some typical vegetable animal foodstuffs with R.S.D. < 6%.