Ultrasonic measurements of the elastic moduli of liquid crystalline polymers

The five independent elastic moduli of extruded rods of two thermotropic liquid crystalline polymers, Vectra B900 and Vectra A950, and the nine independent moduli of an injection-moulded bar of Vectra A950 have been measured by ultrasonic methods at 10 MHz. For Vectra B900, the sharp rise in the axial extensional modulus C33 and the moderate drop in the transverse modulus C11 with increasing draw ratio result from the alignment of molecular chains along the extrusion direction. The chain orientation also leads to an anisotropy in the shear modulus, with the axial shear modulus (C44) exceeding the transverse shear modulus (C66 by > 50%. The mechanical anisotropy in the surface layer of the injection-moulded bar implies that the chains lie mostly in the plane parallel to the wide surface of the bar, and preferentially along the injection direction. The weak anisotropy in the core indicates almost random molecular orientation. Based on the aggregate model, the upper (Voigt) and lower (Reuss) bounds of the elastic modulus of isotropic Vectra B900 have been calculated by using the modulus data of the oriented samples. The observed modulus of isotropic Vectra B900 lies within these bounds and is quite close to the lower bound.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30370/1/0000772.pd

Single-trial event-related potential extraction through one-unit ICA-with-reference.

Objective: In recent years, ICA has been one of the more popular methods for extracting event-related potential (ERP) at the single-trial level. It is a blind source separation technique that allows the extraction of an ERP without making strong assumptions on the temporal and spatial characteristics of an ERP. However, the problem with traditional ICA is that the extraction is not direct and is time-consuming due to the need for source selection processing. In this paper, the application of an one-unit ICA-with-Reference (ICA-R), a constrained ICA method, is proposed. Approach: In cases where the time-region of the desired ERP is known a priori, this time information is utilized to generate a reference signal, which is then used for guiding the one-unit ICA-R to extract the source signal of the desired ERP directly. Main results: Our results showed that, as compared to traditional ICA, ICA-R is a more effective method for analysing ERP because it avoids manual source selection and it requires less computation thus resulting in faster ERP extraction. Significance: In addition to that, since the method is automated, it reduces the risks of any subjective bias in the ERP analysis. It is also a potential tool for extracting the ERP in online application

Sustainable Development Goal 3

Sustainable Development Goals (SDGs) aim to develop a better and sustainable future for the world and the goals are part of an action plan to address poverty, hunger, health, gender equity and various pressing world issues. One of these goals looks at health and wellness. Ageing populations have become a crucial issue worldwide and this short monograph explores ageing and how the consequences of an ageing population may affect our health care system through the case study on Hong Kong's population. The book looks at several critical health issues related to ageing. The elderly, particularly those with low socioeconomic status, rely more on the acute-centric care rather than primary care. The book suggests that secondary care service may only be effective to limited extent as a healthcare measure and an optimum health care system should be one that focuses on primary care. The authors put forth a compelling argument for disease prevention and screening schemes and explain how they are more cost-effective and beneficial to the society and the system. This thoughtful book will provide beneficial insights into the relationship of ageing and sustainable development goals in the context of health and wellness for policy makers and healthcare professionals

Sustainable Development Goal 3

Sustainable Development Goals (SDGs) aim to develop a better and sustainable future for the world and the goals are part of an action plan to address poverty, hunger, health, gender equity and various pressing world issues. One of these goals looks at health and wellness. Ageing populations have become a crucial issue worldwide and this short monograph explores ageing and how the consequences of an ageing population may affect our health care system through the case study on Hong Kong's population. The book looks at several critical health issues related to ageing. The elderly, particularly those with low socioeconomic status, rely more on the acute-centric care rather than primary care. The book suggests that secondary care service may only be effective to limited extent as a healthcare measure and an optimum health care system should be one that focuses on primary care. The authors put forth a compelling argument for disease prevention and screening schemes and explain how they are more cost-effective and beneficial to the society and the system. This thoughtful book will provide beneficial insights into the relationship of ageing and sustainable development goals in the context of health and wellness for policy makers and healthcare professionals

Calculating photonic Green's functions using a non-orthogonal finite difference time domain method

In this paper we shall propose a simple scheme for calculating Green's functions for photons propagating in complex structured dielectrics or other photonic systems. The method is based on an extension of the finite difference time domain (FDTD) method, originally proposed by Yee, also known as the Order-N method, which has recently become a popular way of calculating photonic band structures. We give a new, transparent derivation of the Order-N method which, in turn, enables us to give a simple yet rigorous derivation of the criterion for numerical stability as well as statements of charge and energy conservation which are exact even on the discrete lattice. We implement this using a general, non-orthogonal co-ordinate system without incurring the computational overheads normally associated with non-orthogonal FDTD. We present results for local densities of states calculated using this method for a number of systems. Firstly, we consider a simple one dimensional dielectric multilayer, identifying the suppression in the state density caused by the photonic band gap and then observing the effect of introducing a defect layer into the periodic structure. Secondly, we tackle a more realistic example by treating a defect in a crystal of dielectric spheres on a diamond lattice. This could have application to the design of super-efficient laser devices utilising defects in photonic crystals as laser cavities.Comment: RevTex file. 10 pages with 8 postscript figures. Submitted to Phys Rev

Lack of benefits for prevention of cardiovascular disease with aspirin therapy in type 2 diabetic patients - a longitudinal observational study

<p>Abstract</p> <p>Background</p> <p>The risk-benefit ratio of aspirin therapy in prevention of cardiovascular disease (CVD) remains contentious, especially in type 2 diabetes. This study examined the benefit and harm of low-dose aspirin (daily dose < 300 mg) in patients with type 2 diabetes.</p> <p>Methods</p> <p>This is a longitudinal observational study with primary and secondary prevention cohorts based on history of CVD at enrolment. We compared the occurrence of primary composite (non-fatal myocardial infarction or stroke and vascular death) and secondary endpoints (upper GI bleeding and haemorrhagic stroke) between aspirin users and non-users between January 1995 and July 2005.</p> <p>Results</p> <p>Of the 6,454 patients (mean follow-up: median [IQR]: 4.7 [4.4] years), usage of aspirin was 18% (n = 1,034) in the primary prevention cohort (n = 5731) and 81% (n = 585) in the secondary prevention cohort (n = 723). After adjustment for covariates, in the primary prevention cohort, aspirin use was associated with a hazard-ratio of 2.07 (95% CI: 1.66, 2.59, p < 0.001) for primary endpoint. There was no difference in CVD event rate in the secondary prevention cohort. Overall, aspirin use was associated with a hazard-ratio of 2.2 (1.53, 3.15, p < 0.001) of GI bleeding and 1.71 (1.00, 2.95, p = 0.051) of haemorrhagic stroke. The absolute risk of aspirin-related GI bleeding was 10.7 events per 1,000 person-years of treatment.</p> <p>Conclusion</p> <p>In Chinese type 2 diabetic patients, low dose aspirin was associated with a paradoxical increase in CVD risk in primary prevention and did not confer benefits in secondary prevention. In addition, the risk of GI bleeding in aspirin users was rather high.</p

Community Engagement in Vaccination Promotion: Systematic Review and Meta-Analysis

Background: Community engagement plays a vital role in global immunization strategies, offering the potential to overcome vaccination hesitancy and enhance vaccination confidence. Although there is significant backing for community engagement in health promotion, the evidence supporting its effectiveness in vaccination promotion is fragmented and of uncertain quality. Objective: This review aims to systematically examine the effectiveness of different contents and extent of community engagement for promoting vaccination rates. Methods: This study was performed in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A comprehensive and exhaustive literature search was performed in 4 English databases (PubMed, Embase, Web of Science, and Cochrane Library) and 2 Chinese databases (CNKI and Wan Fang) to identify all possible articles. Original research articles applying an experimental study design that investigated the effectiveness of community engagement in vaccination promotion were eligible for inclusion. Two reviewers independently performed the literature search, study selection, quality assessment, and data extraction. Discrepancies were resolved through discussion, with the arbitration of a third reviewer where necessary. Results: A total of 20 articles out of 11,404 records from 2006 to 2021 were retrieved. The studies used various designs: 12 applied single-group pre-post study designs, 5 were cluster randomized controlled trials (RCTs), and 3 were non-RCTs. These studies targeted multiple vaccines, with 8 focusing on children’s immunization, 8 on human papillomavirus vaccine, 3 on hepatitis B virus vaccine, and 1 on COVID-19 vaccine. The meta-analysis revealed significant increases in vaccination rates both in pre-post comparison (rate difference [RD] 0.34, 95% CI 0.21-0.47, I2=99.9%, P<.001) and between-group comparison (RD 0.18, 95% CI 0.07-0.29, I2=98.4%, P<.001). The meta-analysis revealed that participant recruitment had the largest effect size (RD 0.51, 95% CI 0.36-0.67, I2=99.9%, P<.001), followed by intervention development (RD 0.36, 95% CI 0.23-0.50, I2=100.0%, P<.001), intervention implementation (RD 0.35, 95% CI 0.22-0.47, I2=99.8%, P<.001), and data collection (RD 0.34, 95% CI 0.19-0.50, I2=99.8%, P<.001). The meta-analysis indicated that high community engagement extent yielded the largest effect size (RD 0.49, 95% CI 0.17-0.82, I2=100.0%, P<.001), followed by moderate community engagement extent (RD 0.45, 95% CI 0.33-0.58, I2=99.6%, P<.001) and low community engagement extent (RD 0.15, 95% CI 0.05-0.25, I2=99.2%, P<.001). The meta-analysis revealed that “health service support” demonstrated the largest effect sizes (RD 0.45, 95% CI 0.25-0.65, I2=99.9%, P<.001), followed by “health education and discussion” (RD 0.39, 95% CI 0.20-0.58, I2=99.7%, P<.001), “follow-up and reminder” (RD 0.33, 95% CI 0.23-0.42, I2=99.3%, P<.001), and “social marketing campaigns and community mobilization” (RD 0.24, 95% CI 0.06-0.41, I2=99.9%, P<.001). Conclusions: The results of this meta-analysis supported the effectiveness of community engagement in vaccination promotion with variations in terms of engagement contents and extent. Community engagement required a “fit-for-purpose” approach rather than a “one-size-fits-all” approach to maximize the effectiveness of vaccine promotion. Trial Registration: PROSPERO CRD42022339081; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=33908

A 50-Year-Old Woman with Recurrent Generalised Seizures

Ronald Ma and colleagues discuss the differential diagnosis, investigation, and management of this patient

Folate deficiency increases the incidence of dolutegravir-associated foetal defects in a mouse pregnancy model

Background: Dolutegravir (DTG) is a recommended first-line regimen for all people with Human Immunodeficiency Virus (HIV) infection. Initial findings from Botswana, a country with no folate fortification program, showed an elevated prevalence of neural tube defects (NTDs) with peri-conceptional exposure to DTG. Here we explore whether a low folate diet influences the risk of DTG-associated foetal anomalies in a mouse model. / Methods: C57BL/6 mice fed a folate-deficient diet for 2 weeks, were mated and then randomly allocated to control (water), or 1xDTG (2.5 mg/kg), or 5xDTG (12.5 mg/kg) both administered orally with 50 mg/kg tenofovir disoproxil fumarate 33.3 mg/kg emtricitabine. Treatment was administered once daily from gestational day (GD) 0.5 to sacrifice (GD15.5). Foetuses were assessed for gross anomalies. Maternal and foetal folate levels were quantified. / Findings: 313 litters (103 control, 106 1xDTG, 104 5xDTG) were assessed. Viability, placental weight, and foetal weight did not differ between groups. NTDs were only observed in the DTG groups (litter rate: 0% control; 1.0% 1xDTG; 1.3% 5xDTG). Tail, abdominal wall, limb, craniofacial, and bleeding defects all occurred at higher rates in the DTG groups versus control. Compared with our previous findings on DTG usage in folate-replete mouse pregnancies, folate deficiency was associated with higher rates of several defects, including NTDs, but in the DTG groups only. We observed a severe left-right asymmetry phenotype that was more frequent in DTG groups than controls. / Interpretation: Maternal folate deficiency may increase the risk for DTG-associated foetal defects. Periconceptional folic acid supplementation could be considered for women with HIV taking DTG during pregnancy, particularly in countries lacking folate fortification programs. / Funding: This project has been funded by Federal funds from the Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, under Contract No. HHSN275201800001I and award #R01HD104553. LS is supported by a Tier 1 Canada Research Chair in Maternal-Child Health and HIV. HM is supported by a Junior Investigator award from the Ontario HIV Treatment Network