Spin-Peierls transition in NaV2O5 in high magnetic fields

We investigate the magnetic field dependence of the spin-Peierls transition in NaV$_2$O$_5$ in the field range 16T-30T. The transition temperature exhibits a very weak variation with the field, suggesting a novel mechanism for the formation of the spin-Peierls state. We argue that a charge ordering transition accompanied by singlet formation is consistent with our observations.Comment: 4 pages, 3 figures, final version to appear in Phys. Rev. B (RC

Velocity-force characteristics of an interface driven through a periodic potential

We study the creep dynamics of a two-dimensional interface driven through a periodic potential using dynamical renormalization group methods. We find that the nature of weak-drive transport depends qualitatively on whether the temperature $T$ is above or below the equilibrium roughening transition temperature $T_c$. Above $T_c$, the velocity-force characteristics is Ohmic, with linear mobility exhibiting a jump discontinuity across the transition. For $T \le T_c$, the transport is highly nonlinear, exhibiting an interesting crossover in temperature and weak external force $F$. For intermediate drive, $F>F_*$, we find near $T_c^{-}$ a power-law velocity-force characteristics $v(F)\sim F^\sigma$, with $\sigma-1\propto \tilde{t}$, and well-below $T_c$, $v(F)\sim e^{-(F_*/F)^{2\tilde{t}}}$, with $\tilde{t}=(1-T/T_c)$. In the limit of vanishing drive ($F\ll F_*$) the velocity-force characteristics crosses over to $v(F)\sim e^{-(F_0/F)}$, and is controlled by soliton nucleation.Comment: 18 pages, submitted to Phys. Rev.

New insights into the genetic etiology of Alzheimer's disease and related dementias

Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

Synthesis and hererocyclizations of 3,4-dihydroquinazolin-2-yl guanidine in the search of new anticancer agents

10.3987/COM-09-11672Heterocycles7871761-1775HTCY

Awareness of lifestyle-related cancer risk factors and health promoting behaviours among nurses in Malaysia

Aims and objectives: To assess the awareness of lifestyle-related cancer risk factors and health-promoting behaviors among nurses in Malaysia. Background: The essence of nursing is caring. Nurses are known for taking care of others at the cost of their own health. Lack of self-care among nurses can lead to compassion fatigue, errors on the job, personal health problems and general disdain for life. The nurses' self-care starts with the awareness of modifiable health risk factors and their behaviors in promoting health. Design: A descriptive cross-sectional design. Methods: A total of 357 participants completed the questionnaire in a tertiary referral hospital. The awareness of cancer risk factors was measured based on twenty-nine established lifestyle factors. The health-promoting behaviors were evaluated by the Health-Promoting Lifestyle Profile II. Results: Almost half of the participants are overweight and obese. Awareness among the six clearly established lifestyle-related cancer risk factors showed alcohol gamering the highest number of participants, followed by cured meats, overweight, high red meat diets, low vegetables, and fruit diets, and insufficient physical activity. 37.7% and 47.4% of the participants reported low and moderate levels of health-promoting behavior respectively. The highest mean score reported in the spiritual growth subscale and the lowest in the physical activity subscale. Conclusion: Lifestyle-related cancer risk factors such as overweight, high red meat diets, low vegetables/fruit diets, and insufficient physical activity were not prioritized by the nurses. Although almost half of the nurses reported moderate levels of health-promoting behavior, it is worth noting that the nurses reported of the physical activity subscale to be the least. Relevance to clinical practice: The findings have provided a useful insight into the current health behaviors of nurses and may serve well as an important indicator as to where education and supportive services should target their focus

Linking cohort-based data with electronic health records: a proof-of-concept methodological study in Hong Kong

Objectives Data linkage of cohort-based data and electronic health records (EHRs) has been practised in many countries, but in Hong Kong there is still a lack of such research. To expand the use of multisource data, we aimed to identify a feasible way of linking two cohorts with EHRs in Hong Kong.Methods Participants in the ‘Children of 1997’ birth cohort and the Chinese Early Development Instrument (CEDI) cohort were separated into several batches. The Hong Kong Identity Card Numbers (HKIDs) of each batch were then uploaded to the Hong Kong Clinical Data Analysis and Reporting System (CDARS) to retrieve EHRs. Within the same batch, each participant has a unique combination of date of birth and sex which can then be used for exact matching, as no HKID will be returned from CDARS. Raw data collected for the two cohorts were checked for the mismatched cases. After the matching, we conducted a simple descriptive analysis of attention deficit hyperactivity disorder (ADHD) information collected in the CEDI cohort via the Strengths and Weaknesses of ADHD Symptoms and Normal Behaviour Scale (SWAN) and EHRs.Results In total, 3473 and 910 HKIDs in the birth cohort and CEDI cohort were separated into 44 and 5 batches, respectively, and then submitted to the CDARS, with 100% and 97% being valid HKIDs respectively. The match rates were confirmed to be 100% and 99.75% after checking the cohort data. From our illustration using the ADHD information in the CEDI cohort, 36 (4.47%) individuals had ADHD–Combined score over the clinical cut-off in the SWAN survey, and 68 (8.31%) individuals had ADHD records in EHRs.Conclusions Using date of birth and sex as identifiable variables, we were able to link the cohort data and EHRs with high match rates. This method will assist in the generation of databases for future multidisciplinary research using both cohort data and EHRs