Tetramesityldisilene, a stable compound containing a silicon-silicon double bond

Irradiation of 2,2-bis(2,4,6-trimethylphenyl)hexamethyltrisilane in hydrocarbon solution produces tetramesityldisilene, which can be isolated as a yellow-orange solid stable to room temperature and above in the absence of air. Like the olefins of carbon chemistry, tetramesityldisilene undergoes addition reactions across the silicon-silicon double bond.

Smoking cessation guidelines for health professionals: an update. Health Education Authority

This paper updates the evidence base and key recommendations of the Health Education Authority (HEA) smoking cessation guidelines for health professionals published in Thorax in 1998. The strategy for updating the evidence base makes use of updated Cochrane reviews supplemented by individual studies where appropriate. This update contains additional detail concerning the effectiveness of interventions as well as comments on issues relating to implementation. The recommendations include clarification of some important issues addressed only in general terms in the original guidelines. The conclusion that smoking cessation interventions delivered through the National Health Service are an extremely cost effective way of preserving life and reducing ill health remains unchanged. The strategy recommended by the guidelines involves: (1) GPs opportunistically advising smokers to stop during routine consultations, giving advice on and/or prescribing effective medications to help them and referring them to specialist cessation services; (2) specialist smokers' services providing behavioural support (in groups or individually) for smokers who want help with stopping and using effective medications wherever possible; (3) specialist cessation counsellors providing behavioural support for hospital patients and pregnant smokers who want help with stopping; (4) all health professionals involved in smoking cessation encouraging and assisting smokers in use of nicotine replacement therapies (NRT) or bupropion where appropriate. The key points of clarification of the previous guidelines include: (1) primary health care teams and hospitals should create and maintain readily accessible records on the current smoking status of patients; (2) GPs should aim to advise smokers to stop, and record having done so, at least once a year; (3) inpatient, outpatient, and pregnant smokers should be advised to stop as early as possible and the advice recorded in the notes in a readily accessible form; (4) there is currently little scientific basis for matching individual smokers to particular forms of NRT; (5) NHS specialist smokers' clinics should be the first point of referral for smokers wanting help beyond what can be provided through brief advice from the GP; (6) help from trained health care professionals specialising in smoking cessation such as practice nurses should be available for smokers who do not have access to specialist clinics; (7) the provision of specialist NHS smokers' clinics should be commensurate with demand; this is currently one or two full time clinics or their equivalent per average sized health authority, but demand may rise as publicity surrounding the services increases.

Rain, winds and haze during the Huygens probe's descent to Titan's surface

The irreversible conversion of methane into higher hydrocarbons in Titan's stratosphere implies a surface or subsurface methane reservoir. Recent measurements from the cameras aboard the Cassini orbiter fail to see a global reservoir, but the methane and smog in Titan's atmosphere impedes the search for hydrocarbons on the surface. Here we report spectra and high-resolution images obtained by the Huygens Probe Descent Imager/Spectral Radiometer instrument in Titan's atmosphere. Although these images do not show liquid hydrocarbon pools on the surface, they do reveal the traces of once flowing liquid. Surprisingly like Earth, the brighter highland regions show complex systems draining into flat, dark lowlands. Images taken after landing are of a dry riverbed. The infrared reflectance spectrum measured for the surface is unlike any other in the Solar System; there is a red slope in the optical range that is consistent with an organic material such as tholins, and absorption from water ice is seen. However, a blue slope in the near-infrared suggests another, unknown constituent. The number density of haze particles increases by a factor of just a few from an altitude of 150 km to the surface, with no clear space below the tropopause. The methane relative humidity near the surface is 50 per cent.

Enceladus' Water Vapor Plume

The Cassini spacecraft flew close to Saturn's small moon Enceladus three times in 2005. Cassini's UltraViolet Imaging Spectrograph observed stellar occultations on two flybys and confirmed the existence, composition, and regionally confined nature of a water vapor plume in the south polar region of Enceladus. This plume provides an adequate amount of water to resupply losses from Saturn's E ring and to be the dominant source of the neutral OH and atomic oxygen that fill the Saturnian system.

Stable silylenes

The field of stable silylene research has grown dramatically since the first isolation of a stable silylene in 1994. Prior to 1994, silylenes existed only as reactive intermediates, isolable only in low-temperature matrixes. Since then, several stable silylenes have been synthesized, some in fact showing remarkable thermal stability. This Account highlights the developments in stable silylene chemistry, including theoretical and experimental studies attempting to explain the remarkable stability of the silylenes as well as the rapidly expanding reaction chemistry of the stable silylenes.

Shoulder pain in wheelchair users with tetraplegia and paraplegia

OBJECTIVE

To compare the prevalence and intensity of shoulder pain experienced during daily functional activities in individuals with tetraplegia and individuals with paraplegia who use manual wheelchairs.

DESIGN

Self-report survey.

SETTING

General community.

PARTICIPANTS

Fifty-five women and 140 men, 92 subjects with tetraplegia and 103 subjects with paraplegia who met inclusion criteria of 3 hours per week of manual wheelchair use and at least 1 year since onset of spinal cord injury.

MAIN OUTCOME MEASURES

Respondents completed a demographic and medical history questionnaire and the Wheelchair User's Shoulder Pain Index (WUSPI), a measure of pain during typical daily activities.

RESULTS

More than two thirds of the sample reported shoulder pain since beginning wheelchair use, with 59% of the subjects with tetraplegia and 42% of the subjects with paraplegia reporting current pain. Performance-corrected WUSPI scores were significantly higher in subjects with tetraplegia than in subjects with paraplegia.

CONCLUSIONS

Both the prevalence and intensity of shoulder pain was significantly higher in subjects with tetraplegia than in subjects with paraplegia. Efforts to monitor and prevent shoulder pain should continue after rehabilitation.

Behavioral correlates of individual differences in road-traffic crash risk: an examination method and findings

This article considers methodological issues relevant to the study of differential crash involvement and reviews the findings of research in this area. Aspects of both driving skill and driving style appear to contribute to crash risk. Of the former, hazard-perception latency appears to play an important role, and this may be attributable to generalized abilities to identify visual targets in a complex background and to switch attention rapidly. Of the latter, faster driving speed and willingness to commit driving violations increase crash risk, and these factors may be explicable in terms of personality and antisocial motivation. The article concludes with an examination of the practical implications and of the ways in which research in this area might usefully proceed.

Prevalence, diagnosis and relation to tobacco dependence of chronic obstructive pulmonary disease in a nationally representative population sample

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is the fourth most common cause of death worldwide. It is caused primarily by cigarette smoking. Given its importance, it is remarkable that reliable national prevalence data are lacking for most countries. This study provides estimates of the national prevalence of COPD in England, the extent of under-detection of the disorder, and patterns of cigarette smoking, dependence, and motivation to stop smoking in those with the disease.

METHODS

Data from 8215 adults over the age of 35 who participated in the Health Survey for England were analysed. Information was obtained on self-reported and cotinine validated smoking status, cigarette dependence, motivation to stop smoking, COPD defined by spirometry using joint American Thoracic Society and European Respiratory Society criteria, and self-reports of diagnosis with respiratory disorders.

RESULTS

Spirometry-defined COPD was present in 13.3% (95% CI 12.6 to 14.0) of participants, over 80% of whom reported no respiratory diagnosis. Even among people with severe or very severe COPD by spirometric assessment, only 46.8% (95% CI 39.1 to 54.6) reported any diagnosed respiratory disease. A total of 34.9% (95% CI 32.1 to 37.8) of people with spirometry-defined COPD were smokers compared with 22.4% (95% CI 21.4 to 23.4) of those without, and smoking prevalence increased with disease severity. Smokers with spirometry-defined COPD were more cigarette dependent but had no greater desire to quit than other smokers.

CONCLUSION

COPD is common among adults in England and is predominantly undiagnosed. In smokers it is associated with higher degrees of cigarette dependence but not with a greater motivation to stop smoking.

Predictive validity of the Motivation To Stop Scale (MTSS): a single-item measure of motivation to stop smoking

BACKGROUND

Many different measures of motivation to stop smoking exist but it would be desirable to have a brief version that is standard for use in population surveys and for evaluations of interventions to promote cessation. The aim of this study was to assess the predictive validity and accuracy of the single-item Motivation To Stop Scale (MTSS).

METHODS

This study is part of the "Smoking Toolkit Study;" a monthly survey of representative samples of the English population. We used data from 2483 respondents to the surveys from November 2008 to January 2011, who were smokers, used the MTSS, and were followed up 6 months later to provide information on quit attempts since baseline. The MTSS consists of one item with seven response categories ranging from 1 (lowest) to level 7 (highest level of motivation to stop smoking).

RESULTS

A total of 692 smokers (27.9% (95% CI=26.1-29.6)) made an attempt to quit smoking between baseline and 6-month follow-up. The odds of quit attempts increased linearly with increasing level of motivation at baseline (p<0.001) and were 6.8 (95% CI=4.7-9.9) times higher for the highest level of motivation compared with the lowest. The accuracy of the MTSS for discriminating between smokers who did and did not attempt to quit was ROC(AUC)=0.67 (95% CI=0.65-0.70).

CONCLUSIONS

The MTSS provides strong and accurate prediction of quit attempts and is a candidate for a standard single-item measure of motivation to stop smoking. Further research should assess the external validity of this measure in different smoking populations.

Cassini Radar Views the Surface of Titan

The Cassini Titan Radar Mapper imaged about 1% of Titan's surface at a resolution of approximately 0.5 kilometer, and larger areas of the globe in lower resolution modes. The images reveal a complex surface, with areas of low relief and a variety of geologic features suggestive of dome-like volcanic constructs, flows, and sinuous channels. The surface appears to be young, with few impact craters. Scattering and dielectric properties are consistent with porous ice or organics. Dark patches in the radar images show high brightness temperatures and high emissivity and are consistent with frozen hydrocarbons.

Event-related neural activity associated with the Stroop task

The time course of neural activity supporting performance during the Stroop task was investigated using event-related brain potentials (ERPs). Four spatially and temporally distinct modulations were observed differentiating the ERPs elicited by incongruent trials from the ERPs elicited by congruent, neutral, or word identification trials. Two of these modulations reflected increased negativity over the fronto-central region and positivity over the fronto-polar region for incongruent trials and may reflect conflict detection and resolution processes. The other modulations, distributed over the left parietal and temporo-parietal regions, may reflect the activity of a meaning-based conceptual level system active during congruent, neutral, and word identification trials; and the activity of a perceptual level system supporting task performance when only color information can guide an efficient response on incongruent trials.

Cassini Observes the Active South Pole of Enceladus

Cassini has identified a geologically active province at the south pole of Saturn's moon Enceladus. In images acquired by the Imaging Science Subsystem (ISS), this region is circumscribed by a chain of folded ridges and troughs at approximately 55 degrees S latitude. The terrain southward of this boundary is distinguished by its albedo and color contrasts, elevated temperatures, extreme geologic youth, and narrow tectonic rifts that exhibit coarse-grained ice and coincide with the hottest temperatures measured in the region. Jets of fine icy particles that supply Saturn's E ring emanate from this province, carried aloft by water vapor probably venting from subsurface reservoirs of liquid water. The shape of Enceladus suggests a possible intense heating epoch in the past by capture into a 1:4 secondary spin/orbit resonance.

Guidelines on the use of liver biopsy in clinical practice from the British Society of Gastroenterology, the Royal College of Radiologists and the Royal College of Pathology

Liver biopsy is required when clinically important information about the diagnosis, prognosis or management of a patient cannot be obtained by safer means, or for research purposes. There are several approaches to liver biopsy but predominantly percutaneous or transvenous approaches are used. A wide choice of needles is available and the approach and type of needle used will depend on the clinical state of the patient and local expertise but, for non-lesional biopsies, a 16-gauge needle is recommended. Many patients with liver disease will have abnormal laboratory coagulation tests or receive anticoagulation or antiplatelet medication. A greater understanding of the changes in haemostasis in liver disease allows for a more rational, evidence-based approach to peri-biopsy management. Overall, liver biopsy is safe but there is a small morbidity and a very small mortality so patients must be fully counselled. The specimen must be of sufficient size for histopathological interpretation. Communication with the histopathologist, with access to relevant clinical information and the results of other investigations, is essential for the generation of a clinically useful report.

Smoking cessation and smoking patterns in the general population: a 1-year follow-up

OBJECTIVE

To assess the prevalence of motivation and behaviours relating to smoking cessation and attempts at harm minimization and the stability of these over a 1-year period; to identify demographic, social, behavioural and psychological predictors of attempts to stop smoking and the success of these attempts.

DESIGN

Face-to-face interviews were carried out with a national sample of UK smokers in April/May 1996 with follow-up 1 year later.

SUBJECTS

The original response rate was 61% (1478 of 1911 adult smokers), and of these 1012 were followed-up 1 year later (68% of those who were originally contactable).

RESULTS

Thirty-one per cent of smokers reported making at least one quit attempt during the follow-up period and 17% made a quit attempt in the first 9 months of that period. Of these 29% were still not smoking at least 3 months later. Fifty-one per cent of smokers had tried to cut down in the year leading up to the first survey. There was a fair degree of consistency over time in individual smokers' desires and intentions to stop smoking across both surveys and in the incidence of quit attempts and attempts to cut down. Beliefs about the effects of smoking on future health and having a partner who disliked their smoking were positively associated with making a quit attempt at follow-up while reporting enjoying smoking at baseline was negatively associated with making a quit attempt at follow-up. Time to first cigarette of the day and age of starting smoking were positively associated with success of quit attempts.

CONCLUSIONS

Motivation and behaviours relating to smoking cessation are prevalent and fairly stable over time. Different factors appear to be related to attempts to stop and the success of those attempts. Interventions to increase smoking cessation in the population should take account of this.

RAS, FMS and p53 mutations and poor clinical outcome in myelodysplasias: a 10-year follow-up

The molecular mechanisms underlying the development and evolution of myelodysplastic syndrome (MDS) are largely unknown. The increasing number of blast cells in the bone marrow correlate with poor prognosis and risk of developing acute leukemia. Such progression is frequently associated with increasing chromosomal abnormalities and genetic mutations. A cohort of 75 MDS patients were investigated for RAS, FMS and p53 mutations, and these molecular findings were related to cytogenetics, clinical status, transformation to acute leukemia, prognostic scores and survival. A mutation incidence of 57% (43/75) was found, with 48% (36/75) RAS mutations, 12% (9/75) FMS mutations and 8% (4/50) p53 mutations. The mutation status for RAS and FMS was related to MDS subgroup, increasing with poor-risk disease. The highest incidence was in the chronic myelomonocytic leukemia (CMML) subgroup. The most frequent RAS mutations were of codon 12 and a predominance of FMS codon 969 mutations was observed. A statistically significant increased frequency of transformation to AML was observed in MDS patients harboring RAS or FMS mutations (P < 0.02). Patients with oncogene mutations had a significantly poorer survival compared with those without mutations at 2 years and at the end of the period of follow-up (P < 0.02). Multivariate analysis including mutation, age, gender, diagnosis (FAB), cytogenetics and International score shows that the International score and mutation and age is the best predictive model of a poor outcome, (P < 0.0001). When the analysis was undertaken without the International score, mutation and gender was the best predictor of poor survival (P = 0.005). This study shows that oncogene mutation, indicative of genetic instability, is associated with disease progression and poor survival in MDS.

Effects of task context and fluctuations of attention on neural activity supporting performance of the stroop task

The influence of task context and transient fluctuations in attentional control on neural processes supporting performance of the Stroop task was investigated using event-related brain potentials. Task context was manipulated by varying the proportion of congruent and incongruent trials across different blocks of trials, and fluctuations of attentional control were considered by examining differences between trials eliciting faster and slower responses. The amplitudes of the N450, thought to reflect the suppression of a conceptual level processing system, and a temporo-parietal slow wave, thought to index the processing of color information, were greater when trials were mostly congruent in comparison to when trials were mostly incongruent. These findings indicate that the neural systems supporting inhibition and color processing are modulated by task demands. For the N450 the effect of task context interacted with the efficiency of attentional control being present for those trials eliciting faster responses and not for those trials eliciting slower responses. This finding is consistent with those from a growing number of studies indicating that the neural systems supporting attentional control are transient in nature, tending to fluctuate in efficiency over time.

Spatiotemporal analysis of experimental differences in event-related potential data with partial least squares

One challenge in the analysis of event-related potentials (ERPs) is to identify task-related differences in scalp topography. The multivariate Partial Least Squares (PLS) analysis was used to identify the spatiotemporal distribution of ERP differences related to experimental manipulations. Two simulations included latency shifts and amplitude changes at peaks with temporal overlap. PLS identified effects only at modeled timepoints and electrodes. In contrast, principal components analysis identified differences at most timepoints. We also demonstrated that PLS identified combinations of waveform differences, not isolated sources. ERP components in an auditory oddball task were also assessed with PLS. The primary distinction was between ERPs on hit and correct rejection trials, expressed at multiple timepoints and electrodes. PLS provides a mechanism to describe experimental differences in ERP waveforms, simultaneously across the head.

Cassini Imaging Science: Initial Results on Saturn's Rings and Small Satellites

Images acquired of Saturn's rings and small moons by the Cassini Imaging Science Subsystem (ISS) during the first 9 months of Cassini operations at Saturn have produced many new findings. These include new saturnian moons; refined orbits of new and previously known moons; narrow diffuse rings in the F-ring region and embedded in gaps within the main rings; exceptionally fine-scale ring structure in moderate- to high-optical depth regions; new estimates for the masses of ring-region moons, as well as ring particle properties in the Cassini division, derived from the analysis of linear density waves; ring particle albedos in select ring regions; and never-before-seen phenomena within the rings.

Randomized comparative trial of nicotine polacrilex, a transdermal patch, nasal spray, and an inhaler

BACKGROUND

There are several nicotine replacement products on the market, and physicians are likely to be asked with increasing frequency about which of these products their patients should use.

OBJECTIVE

To provide a basis for rational advice by comparing nicotine polacrilex (gum), a transdermal patch, nasal spray, and an inhaler.

DESIGN

Randomized trial with assessments at the quit date and 1, 4, and 12 weeks later.

SETTING

Hospital smokers' clinic.

PATIENTS

Male and female community volunteers (N = 504) smoking 10 or more cigarettes per day and seeking help to stop smoking.

INTERVENTIONS

Patients were given brief advice, and purchased their nicotine replacement treatment at approximately half the regular retail price.

MAIN OUTCOME MEASURES

Nicotine replacement treatment use, ratings of withdrawal symptoms, ratings of product characteristics and helpfulness, and biochemically validated continuous lapse-free abstinence.

RESULTS

The products did not differ in their effects on withdrawal discomfort, urges to smoke, or rates of abstinence. The continuous validated 12-week abstinence rates were 20%, 21%, 24%, and 24% in the gum, patch, spray, and inhaler groups, respectively. Compliance with recommended nicotine replacement treatment use was high for the patch, low for gum, and very low for the spray and the inhaler. The spray was underused because of adverse effects more often than the other products. In the subjects using the spray, the level of use among abstainers at week 1 predicted outcome at week 12. The inhaler was rated as more embarrassing to use than the other products, but provided at least as much nicotine as the gum.

CONCLUSION

When asked about nicotine replacement treatment products available, physicians should note that, despite low compliance with the recommended dose of the spray and inhaler and differences in product ratings, overall, there are no notable differences between the products in their effects on withdrawal discomfort, perceived helpfulness, or general efficacy.

Use of lacZ fusions to delimit regulatory elements of the inducible divergent GAL1-GAL10 promoter in Saccharomyces cerevisiae

We present the DNA sequence of a 914-base pair fragment from Saccharomyces cerevisiae that contains the GAL1-GAL10 divergent promoter, 140 base pairs of GAL10 coding sequence, and 87 base pairs of GAL1 coding sequence. From this fragment, we constructed four pairs of GAL1-lacZ and GAL10-lacZ fusions on various types of yeast plasmid vectors. On each type of vector, the fused genes were induced by galactose and repressed by glucose. The response of a GAL1-lacZ fusion to gal4 and gal80 regulatory mutations was similar to the response of intact chromosomal GAL1 and GAL10 genes. A set of deletions that removed various portions of the GAL10 regulatory sequences from a GAL10-CYC1-lacZ fusion was constructed in vitro. These deletions defined a relatively guanine-cytosine-rich region of 45 base pairs that contained sequences necessary for full-strength galactose induction and an adjacent guanine-cytosine rich 55 base pairs that contained sequences sufficient for weak induction.

A randomized, controlled trial of child psychiatric assessments conducted using videoconferencing

We used a PC-based videoconferencing system to conduct child psychiatry assessments. The telecommunications link was six digital lines, giving a total bandwidth of 336 kbit/s. Twenty-three patients (aged 4-16 years), accompanied by their parents, completed two psychiatric assessments, one via videoconferencing and another face to face (FTF). The order of assessments was randomized. Questionnaires were used to record the diagnosis, treatment recommendations and the psychiatrists', patients' and their parents' satisfaction with each assessment. An independent evaluator concluded that in 22 cases (96%) the diagnosis and treatment recommendations made via the videoconferencing system were the same as those made FTF. The psychiatrists stated that videoconferencing assessments were an adequate alternative to FTF assessments and did not interfere with diagnosis. However, the responses from the psychiatrist satisfaction questionnaire showed that they preferred FTF assessments. No significant difference was found in the patients' or parents' satisfaction responses after the two types of assessment. The majority of children (82%) 'liked' using the telepsychiatry system and six (26%) preferred it to a FTF assessment. Most parents (91%) indicated that they would prefer to use the videoconferencing system than to travel a long distance to see a psychiatrist in person.

Cassini Imaging Science: Initial Results on Phoebe and Iapetus

The Cassini Imaging Science Subsystem acquired high-resolution imaging data on the outer Saturnian moon, Phoebe, during Cassini's close flyby on 11 June 2004 and on Iapetus during a flyby on 31 December 2004. Phoebe has a heavily cratered and ancient surface, shows evidence of ice near the surface, has distinct layering of different materials, and has a mean density that is indicative of an ice-rock mixture. Iapetus's dark leading side (Cassini Regio) is ancient, heavily cratered terrain bisected by an equatorial ridge system that reaches 20 kilometers relief. Local albedo variations within and bordering Cassini Regio suggest mass wasting of ballistically deposited material, the origin of which remains unknown.

Smoking cessation in patients with respiratory diseases: a high priority, integral component of therapy

Smoking cessation is the one of the most important ways to improve the prognosis of patients with respiratory disease. The Task Force on guidelines for smoking cessation in patients with respiratory diseases was convened to provide evidence-based recommendations on smoking cessation interventions in respiratory patients. Based on the currently available evidence and the consensus of an expert panel, the following key recommendations were made. 1) Patients with respiratory disease have a greater and more urgent need to stop smoking than the average smoker, so respiratory physicians must take a proactive and continuing role with all smokers in motivating them to stop and in providing treatment to aid smoking cessation. 2) Smoking cessation treatment should be integrated into the management of the patient's respiratory condition. 3) Therapies should include pharmacological treatment (i.e. nicotine replacement therapy, bupropion or varenicline) combined with behavioural support. 4) Respiratory physicians should receive training to ensure that they have the knowledge, attitudes and skills necessary to deliver these interventions or to refer to an appropriate specialist. 5) Although the cost of implementing these recommendations will partly be offset by a reduction in attendance for exacerbations, etc., a budget should be established to enable implementation. Research is needed to establish optimum treatment strategies specifically for respiratory patients.