To Be or Not To Be Polar: The Ferroelectric and Antiferroelectric Nematic Phases

We report two new series of compounds that show the ferroelectric nematic, NF, phase in which the terminal chain length is varied. The longer the terminal chain, the weaker the dipole-dipole interactions of the molecules are along the director and thus the lower the temperature at which the axially polar NF phase is formed. For homologues of intermediate chain lengths, between the non-polar and ferroelectric nematic phases, a wide temperature range nematic phase emerges with antiferroelectric character. The size of the antiparallel ferroelectric domains critically increases upon transition to the NF phase. In dielectric studies, both collective ("ferroelectric") and non-collective fluctuations are present, and the "ferroelectric" mode softens weakly at the N-NX phase transition because the polar order in this phase is weak. The transition to the NF phase is characterized by a much stronger lowering of the mode relaxation frequency and an increase in its strength, and a typical critical behavior is observed.

From drugs to dry mouth: a rapid systematic review exploring health implications of dry mouth in older adults with polypharmacy

Introduction

Approximately 60% of older adults complain of dry mouth which may be associated with polypharmacy, common in this population. Existing studies have reported treatment approaches to dry mouth but do not address long-term, preventative measures that would more positively benefit the health and wellbeing of older adults.1

Aim

This rapid systematic review aims to identify the implications of dry mouth on the physical and psychological wellbeing of older adults with polypharmacy to establish the importance of preventing dry mouth.

Methods

Studies reporting health implications of dry mouth, in relation to polypharmacy in older adults (>65 years old), were included in this rapid systematic review. MEDLINE, EMBASE, PsycINFO and CINAHL databases were searched using Keywords such as ‘polypharmacy’, ‘dry mouth’, ‘oral health’ and ‘quality of life’ (PROSPERO: CRD42021288945). Joanna Briggs Institute critical appraisal tools were used to assess study quality. Ethical approval was not required for this project due to the methodology of this rapid systematic review.

Results

Of the 6,852 citations screened, 9 studies (cross-sectional, n = 8; longitudinal, n = 1) were included which comprised 37,459 participants (mean age range: 68.5-85.0 years). Studies were published between 2005 and 2019. Meta-analysis was not possible due to the heterogenicity of outcomes reported; instead, a narrative synthesis was undertaken. The health implications identified in this review were categorised as ‘physical’, such as tooth loss, or ‘psychological’, such as depression. The main physical health implications reported in the studies related to dental health, such as tooth loss and gingivitis, as well as functional impairments, such as chewing and swallowing difficulties. An increase in the number of medicines taken, from 0 to 5, decreased the number of natural teeth remaining from 16.35 ±8.58 to 11.74 ±7.88, respectively. Additionally, the number of dental complications increased from 1.43 ±2.1 to 2.33 ±2.2 as the number of medicines increased from 1 to >3, respectively. There was a paucity of studies (n = 2) that investigated the psychological health implications of dry mouth upon older adult populations. Depression, was however, identified as a significant consequence of dry mouth in older adults with a prevalence as high as 64%.2 An additional 6 psychological health implications were identified, for example, self-consciousness.

Discussion/Conclusion

This review examined the health implications of dry mouth in relation to polypharmacy in older adults, including physical health and psychological health implications. There were limitations in this review; for example, the predominant cross-sectional study design restricted findings due to the inability to establish longitudinal associations. High levels of physical health implications of dry mouth were observed in older adults with polypharmacy and, to a lesser extent, psychological health implications. The modifiable nature of polypharmacy could pave the way for prevention strategies of dry mouth. The optimisation of medication regimens, to effectively treat chronic conditions but also limit the likelihood of dry mouth, is a practical approach to achieve this.3

References

1. Villa A, Abati S. Risk factors and symptoms associated with xerostomia: a cross-sectional study. Aust Dent J. 2011;56(3):290-5.

2. Rech RS, Neves Hugo F, Torres LHN, Hilgert JB. Factors associated with hyposalivation and xerostomia in older persons in South Brazil. Gerodontology. 2019;36(4):338-44.

3. Cheong ST, Ng TM, Tan KT. Pharmacist-initiated deprescribing in hospitalised elderly: prevalence and acceptance by physicians. Eur J Hosp Pharm. 2018;25:35-9.

Recombinant activated protein C usage in Scotland: a comparison with published guidelines and a survey of attitudes

Severe sepsis is a common cause of admission to the intensive care unit and is associated with a high hospital mortality. This audit explored the current use of, and attitudes towards, recombinant activated protein C therapy across Scotland, and compared these with current guidance. Patients with severe sepsis were followed for three days. Consideration and/or usage of recombinant activated protein C were compared with two different guidelines. Ninety-seven patients were admitted to the intensive care unit over the audit period. Recombinant activated protein C was used in nine of these patients. Depending on the criteria used, between 50% and 81% of the patients who qualified for recombinant activated protein C therapy did not receive it. Subsequent to the audit, a survey was performed to study intensive care unit consultants' attitudes to recombinant activated protein C therapy. A total of 125 consultants responded to the survey (77%). Of these, 104 (83%) stated that they used recombinant activated protein C in their clinical practice, 56 (52%) of whom prescribed it to patients with two-organ failures and an Acute Physiology and Chronic Health Evaluation II score of ≥ 25. Thirty-nine respondents (38%) stated that two-organ failures alone would be an adequate trigger for therapy. We conclude that recombinant activated protein C is potentially under-used to treat severe sepsis. Many consultants seem to reserve the drug for the most severely ill sub group of patients.

Engineering a novel self-powering electrochemical biosensor

This paper records the efforts of a multi-disciplinary team of undergraduate students from Glasgow University to collectively design and carry out a 10 week project in Synthetic Biology as part of the international Genetic Engineered Machine competition (iGEM). The aim of the project was to design and build a self-powering electrochemical biosensor called ‘ElectrEcoBlu’. The novelty of this engineered machine lies in coupling a biosensor with a microbial fuel cell to transduce a pollution input into an easily measurable electrical output signal. The device consists of two components; the sensor element which is modular, allowing for customisation to detect a range of input signals as required, and the universal reporter element which is responsible for generating an electrical signal as an output. The genetic components produce pyocyanin, a competitive electron mediator for microbial fuel cells, thus enabling the generation of an electrical current in the presence of target chemical pollutants. The pollutants tested in our implementation were toluene and salicylate. ElectrEcoBlu is expected to drive forward the development of a new generation of biosensors. Our approach exploited a range of state-of-the-art modelling techniques in a unified framework of qualitative, stochastic and continuous approaches to support the design and guide the construction of this novel biological machine. This work shows that integrating engineering techniques with scientific methodologies can provide new insights into genetic regulation and can be considered as a reference framework for the development of biochemical systems in synthetic biology.