A study of the molecular dynamics of compounds containing rotor groups of c(_3) symmetry

Models for calculation of barriers to rotation from torsional mode frequencies were reviewed, and a new simple harmonic quantum mechanical treatment of two coaxial rotors with both internal and external barriers was developed. Torsional and librational mode frequencies of several sets of compounds containing hydrogenous rotor groups were obtained principally by incoherent inelastic neutron scattering, with reference to both new and old infrared and Raman studies. The internal and external potentials in the N(_2)H(_6)(^+2) halide salts were calculated using the new model. The external barriers were used to calculate the appreciable hydrogen bond strengths, and the internal barrier was found to be less than in ethane. The different phases of the monomethylammonium halide and PF(_6)(^-)salts were studied, including selective deuteration studies, and the new model again applied to obtain barriers. The model worked well for the chloride p-phase but began to break down for the bromide indicating loss of simple harmonic behaviour. The other phases all displayed non-harmonic behaviour. The internal barrier was found tobe intermediate between that of N(_2)H(_6)(^+2) and C(_2)H(_6). In the C(_6)H(_5)NH(_3)(^+)C1(^-) and Br(^-) salts the internal barrier was found to be very small, and the external -NH(_3)(^+) torsional barrier for the chloride was in good agreement with that in N(_2)H(_6)(^+2)C1(_2)(6-). A large number of methyl-halogeno compounds of the group IV elements were studied. Multiple top torsional mode frequency splittings were observed and their neutron scattering intensities related to their mode degeneracies. Several previous I.R. determinations were shown to be in error. The di-, tri- and tetra-methylammonium halide salts were studied and torsional mode splittings were again observed. Barriers to methyl rotation were found to be relatively high, and steric effects due to the short C-N bond length, and external influences, were found to be quite important

Aspects of birth history and outcome in diplegics attending specialised educational facilities

Aim. We aimed to study functional mobility and visual performancein spastic diplegic children and adolescents attending specialisedschools.Methods. Spastic diplegia (SD) was confirmed by clinical examination. Birth and related history were added to explore relationships between SD, birth weight (BW) and duration of pregnancy. Place of birth, BW, gestational age (GA) and length of hospital stay were obtained by means of parental recall. Outcome measures included the functional mobility scale (FMS) and Beery tests of visuomotor integration (VMI) and visual perception (VIS).Results. Forty participants were included (age 7 years 5 months – 19 years 6 months). Term and preterm births were almost equally represented. Functional mobility assessments showed that 20 were walking independently in school and community settings and the remainder used walking aids or wheelchairs. There were no significant correlations between BW or GA and outcomes (FMS, VIS-z-scores or VMI-z-scores) and z-scores were low. VIS scores correlated significantly with chronological age (p=0.024). There were also significant correlations between VIS and VMI scores and school grade appropriateness (p=0.004; p=0.027, respectively). Interpretation. Both term and preterm births were represented, and outcomes were similar regardless of GA. VIS and VMIwere affected in both groups. Half of the group used assistive mobility devices and three-quarters were delayed in terms of their educational level. These problems require specialised teaching strategies, appropriate resources and a school environment that caters for mobility limitations

Letter: Faecal volatile organic metabolites, promising biomarkers in inflammatory bowel disease and Letter: Faecal volatile organic metabolites as novel diagnostic biomarkers in inflammatory bowel disease. Authors' reply

The aetiology of inflammatory bowel disease (IBD) remains poorly understood. Recent evidence suggests an important role of gut microbial dysbiosis in IBD, and this may be associated with changes in faecal volatile organic metabolites (VOMs).To describe the changes in the faecal VOMs of patients with IBD and establish their diagnostic potential as non-invasive biomarkers.Faecal samples were obtained from 117 people with Crohn's disease (CD), 100 with ulcerative colitis (UC), and 109 healthy controls. Faecal VOMs were extracted using solid-phase micro-extraction and analysed by gas chromatography mass spectrometry. Data analysis was carried out using partial least squares-discriminate analysis (PLS-DA) to determine class membership based on distinct metabolomic profiles.The PLS-DA model showed clear separation of active CD from inactive disease and healthy controls (P < 0.001). Heptanal, 1-octen-3-ol, 2-piperidinone and 6-methyl-2-heptanone were up-regulated in the active CD group [variable important in projection (VIP) score 2.8, 2.7, 2.6 and 2.4, respectively], while methanethiol, 3-methyl-phenol, short-chain fatty acids and ester derivatives were found to be less abundant (VIP score of 3.5, 2.6, 1.5 and 1.2, respectively). The PLS-DA model also separated patients with small bowel CD from healthy controls and those with colonic CD from UC (P < 0.001). In contrast, less distinct separation was observed between active UC, inactive UC and healthy controls.Analysis of faecal volatile organic metabolites can provide an understanding of gut metabolomic changes in IBD. It has the potential to provide a non-invasive means of diagnosing IBD, and can differentiate between UC and CD

Proton spin-lattice relaxation and methyl group rotation

Proton spin-lattice relaxation times have been measured at 16, 31, and 59 MHz in 4-methyl-2,6-ditertiarybutyl phenol between 80 K and its melting point, 340 K. The variation of T1 with temperature shows too distinct minima. The lower-temperature minimum has been analyzed in terms of relaxation by reorientation of four of the six t-butyl methyl groups with an average apparent activation energy of about 2.4 kcal mole−1 (104 meV molecule−1). The higher-temperature minimum has been analyzed in terms of relaxation by reorientation of the t-butyl groups about their C3 axes with four of the six t-butyl methyl groups reorienting very rapidly, and the remaining two reorienting with correlation time similar to that of the t-butyl group. The activation energy for the higher-temperature minimum is 5.76 kcal mole−1 (250 meV molecule−1). Steric potential calculations are used to add weight to these assignments, and a number of peculiarities displayed by the lower-temperature minimum are discussed

Proton spin-lattice relaxation and methyl group rotation

Proton spin-lattice relaxation times have been measured at 16, 31, and 59 MHz in 4-methyl-2,6-ditertiarybutyl phenol between 80 K and its melting point, 340 K. The variation of T1 with temperature shows too distinct minima. The lower-temperature minimum has been analyzed in terms of relaxation by reorientation of four of the six t-butyl methyl groups with an average apparent activation energy of about 2.4 kcal mole−1 (104 meV molecule−1). The higher-temperature minimum has been analyzed in terms of relaxation by reorientation of the t-butyl groups about their C3 axes with four of the six t-butyl methyl groups reorienting very rapidly, and the remaining two reorienting with correlation time similar to that of the t-butyl group. The activation energy for the higher-temperature minimum is 5.76 kcal mole−1 (250 meV molecule−1). Steric potential calculations are used to add weight to these assignments, and a number of peculiarities displayed by the lower-temperature minimum are discussed

Effect of preoperative delay on prognosis for patients with early stage non-small cell lung cancer

AbstractObjective: Screening for lung cancer will discover many nodules of indeterminate pathology. Observation has the theoretic risk of permitting dissemination of a localized cancer and worsening prognosis, whereas immediate evaluation of benign conditions generates morbidity and cost. This study was conducted to assess the effect of delay in surgical intervention on survival for patients with early stage non-small cell lung cancer. Methods: Records for patients with resected pathologic stage I and II non-small cell lung cancer (1989-1999) were abstracted for patient age, race, sex, medical history, date of presentation, date and type of surgical treatment, pathologic stage, and date of death or last follow-up. Kaplan-Meier survival analysis was performed to test for the effect of delay (time from presentation to surgical intervention) on survival. Results: Eighty-four patients were identified. Median age was 66 years, median preoperative interval was 82 days (range, 1-641 days), and median follow-up was 3.3 years (range, 5 days-11.9 years). Median survival was 3.7 years. Overall 5-year survival was 40%; disease-specific 5-year survival was 63%. Log-rank analysis of the effect of delay on overall survival generated a P value of.54, with an estimated hazard ratio for a 90-day delay of 1.06 (95% confidence interval, 0.87-1.30). Conclusions: For this population, we were unable to detect a significant effect of delay on prognosis. Although these results suggest that the risk of judicious observation of indeterminate pulmonary nodules might be low, the 95% confidence interval is broad. Larger sample sizes are needed to reach definitive conclusions.J Thorac Cardiovasc Surg 2003;125:108-1

Are people in residential care entitled to receive rehabilitation services following hip fracture? Views of the public from a citizens' jury.

BACKGROUND:Access to rehabilitation services for people living in residential care facilities is frequently limited. A randomised trial of a hospital outreach hip fracture rehabilitation program in residential care facilities has demonstrated improvements in mobility at four weeks and quality of life at 12 months but was not considered cost-effective by standard health economic metrics. The current study aimed to explore the general public's views on issues involved in the allocation of rehabilitation resources for residents of care facilities. METHODS:A citizens' jury comprising 13 purposively sampled members of the general public, representative of the South Australian age, gender and household income profile. The jury considered the questions "Should there be an investment of physical rehabilitation services in residential care for older people following a hip fracture? If so, what is the best way of providing this service (considering funding, models of service delivery and equity)?" Deliberations were in the context of a state-wide health reform program. The jury was conducted over two days with an experienced independent facilitator, addressing questions developed by a steering group of research academics and clinicians. RESULTS:The mean age of the citizens' jury members was 43 (range 26 to 61). Eleven members voted for investment in outreach hospital rehabilitation services in residential aged care. All jurors agreed a number of strategies in addition to investment should be implemented, including health care planning and decision making, increased emphasis on hip fracture prevention, training of aged care staff in rehabilitation and routine provision of hospital discharge summaries to families. The jury further advocated for an increased focus on rehabilitation in residential care, potentially through accreditation criteria, increasing health literacy of residents and families, implementation of age friendly environment strategies and improving connections of care facilities with community, hospital and tertiary services. CONCLUSIONS:This citizens' jury representative of the general public recommends that regardless of dementia and frailty, people who live in residential care and are walking and fracture their hips should have access to hospital outreach rehabilitation and recovery services

Estimation of the particle concentration in hydraulic liquid by the in-line automatic particle counter based on the CMOS image sensor

Modern hydraulic systems should be monitored on the regular basis. One of the most effective ways to address this task is utilizing in-line automatic particle counters (APC) built inside of the system. The measurement of particle concentration in hydraulic liquid by APC is crucial because increasing numbers of particles should mean functional problems. Existing automatic particle counters have significant limitation for the precise measurement of relatively low concentration of particle in aerospace systems or they are unable to measure higher concentration in industrial ones. Both issues can be addressed by implementation of the CMOS image sensor instead of single photodiode used in the most of APC. CMOS image sensor helps to overcome the problem of the errors in volume measurement caused by inequality of particle speed inside of tube. Correction is based on the determination of the particle position and parabolic velocity distribution profile. Proposed algorithms are also suitable for reducing the errors related to the particles matches in measurement volume. The results of simulation show that the accuracy increased up to 90 per cent and the resolution improved ten times more compared to the single photodiode sensor

Systematic review of 29 self-report instruments for assessing quality of life in older adults receiving aged care services

Background: Quality of life (QoL) outcomes are used to monitor quality of care for older adults accessing aged care services, yet it remains unclear which QoL instruments best meet older adults', providers' and policymakers' needs. This review aimed to (1) identify QoL instruments used in aged care and describe them in terms of QoL domains measured and logistical details; (2) summarise in which aged care settings the instruments have been used and (3) discuss factors to consider in deciding on the suitability of QoL instruments for use in aged care services. Design: Systematic review. Data sources: MEDLINE, EMBASE, PsycINFO, Cochrane Library and CINAHL from inception to 2021. Eligibility criteria: Instruments were included if they were designed for adults (>18 years), available in English, been applied in a peer-reviewed research study examining QoL outcomes in adults >65 years accessing aged care (including home/social care, residential/long-term care) and had reported psychometrics. Data extraction and synthesis: Two researchers independently reviewed the measures and extracted the data. Data synthesis was performed via narrative review of eligible instruments. Results: 292 articles reporting on 29 QoL instruments were included. Eight domains of QoL were addressed: physical health, mental health, emotional state, social connection, environment, autonomy and overall QoL. The period between 1990 and 2000 produced the greatest number of newly developed instruments. The EuroQoL-5 Dimensions (EQ-5D) and Short Form-series were used across multiple aged care contexts including home and residential care. More recent instruments (eg, ICEpop CAPability measure for Older people (ICECAP-O) and Adult Social Care Outcomes Toolkit (ASCOT)) tend to capture emotional sentiment towards personal circumstances and higher order care needs, in comparison with more established instruments (eg, EQ-5D) which are largely focused on health status. Conclusions: A comprehensive list of QoL instruments and their characteristics is provided to inform instrument choice for use in research or for care quality assurance in aged care settings, depending on needs and interests of users