Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

A comparative analysis exposes an amplification delay distinctive to SARS-CoV-2 Omicron variants of clinical and public health relevance

ABSTRACTMutations in the SARS-CoV-2 genome may negatively impact a diagnostic test, have no effect, or turn into an opportunity for rapid molecular screening of variants. Using an in-house Emergency Use Authorized RT-qPCR-based COVID-19 diagnostic assay, we combined sequence surveillance of viral variants and computed PCR efficiencies for mismatched templates. We found no significant mismatches for the N, E, and S set of assay primers until the Omicron variant emerged in late November 2021. We found a single mismatch between the Omicron sequence and one of our assay's primers caused a > 4 cycle delay during amplification without impacting overall assay performance.Starting in December 2021, clinical specimens received for COVID-19 diagnostic testing that generated a Cq delay greater than 4 cycles were sequenced and confirmed as Omicron. Clinical samples without a Cq delay were largely confirmed as the Delta variant. The primer-template mismatch was then used as a rapid surrogate marker for Omicron. Primers that correctly identified Omicron were designed and tested, which prepared us for the emergence of future variants with novel mismatches to our diagnostic assay's primers. Our experience demonstrates the importance of monitoring sequences, the need for predicting the impact of mismatches, their value as a surrogate marker, and the relevance of adapting one's molecular diagnostic test for evolving pathogens.

A MHz X-ray diffraction set-up for dynamic compression experiments in the diamond anvil cell

An experimental platform for dynamic diamond anvil cell (dDAC) research has been developed at the High Energy Density (HED) Instrument at the European X-ray Free Electron Laser (European XFEL). Advantage was taken of the high repetition rate of the European XFEL (up to 4.5 MHz) to collect pulse-resolved MHz X-ray diffraction data from samples as they are dynamically compressed at intermediate strain rates (≤10³ s^-1), where up to 352 diffraction images can be collected from a single pulse train. The set-up employs piezo-driven dDACs capable of compressing samples in ≥340 µs, compatible with the maximum length of the pulse train (550 µs). Results from rapid compression experiments on a wide range of sample systems with different X-ray scattering powers are presented. A maximum compression rate of 87 TPa s^-1 was observed during the fast compression of Au, while a strain rate of ∼1100 s^-1 was achieved during the rapid compression of N₂ at 23 TPa s^-1.

336 ASYMPTOMATIC ORTHOSTATIC HYPOTENSION AND RISK OF FALLS IN COMMUNITY-DWELLING OLDER PEOPLE

Background

Many older people with Orthostatic Hypotension (OH) may not report typical symptoms of dizziness, light-headedness, or unsteadiness. However, the relationships between OH and falls in the absence of typical symptoms are not yet established.

Methods

Continuous orthostatic BP was measured during active stand using a Finometer at Wave 1 of TILDA in participants aged≥70 years. OH, with and without dizziness, was defined as a sustained drop in systolic BP≥20 and/or diastolic BP≥10 mm Hg at 30, 60 and 90 seconds post-standing. The association between symptoms of dizziness and orthostatic BP was assessed with multi-level mixed-effects linear regression; logistic regression models assessed the longitudinal relationship between OH and falls at 6-year follow-up (Waves 2-5).

Results

Almost 11% (n=934; mean age: 75 years; 51% female) had OH, two-thirds of whom were asymptomatic. Dizziness was not associated with systolic BP drop at 30 (β=1.54; –1.27, 4.36; p=0.256), 60 (β=2.6; –0.19, 5.47; p =0.476) or 90 (β=2.02; –0.91, 4.95; p=0.176) seconds after standing in adjusted models. Asymptomatic OH was independently associated with unexplained falls (Odds Ratio: 2.01; 1.11, 3.65; p=0.022) but not explained falls (OR 0.93; 0.53, 1.62; p=0.797) during follow-up.

Conclusion

Two-thirds of older people with OH did not report typical symptoms of light-headedness. Dizziness or unsteadiness after standing did not correlate with the degree of orthostatic BP drop or recovery. Participants with asymptomatic OH had a significantly higher risk of unexplained falls during follow-up, and this has important clinical implications for the assessment of older people with falls.

179 WHAT IS THE RISK OF FALLS DUE TO PSYCHOTROPIC MEDICATIONS IN A LARGE POPULATION-REPRESENTATIVE COHORT OF COMMUNITY-DWELLING OLDER PEOPLE?

Background

Psychotropic medications including antidepressants, anticholinergics, benzodiazepines, ‘Z’ drugs and antipsychotics, are frequently identified as Falls Risk Increasing Drugs (FRIDS), yet there is a relative lack of robust data detailing the prospective risk of falls associated with these drug classes.

Methods

Participants aged ≥65 years from the Irish Longitudinal Study on Ageing (TILDA) were included and followed from Waves 1 to 5 (Mean 7.6 years follow-up). Incidence of falls was ascertained by self-report and unexplained falls were defined as falls not caused by a slip or trip with no apparent cause. Medication lists were examined for medications of interest. Logistic Regression models, reporting odds ratio with 95% confidence intervals, were used to assess the association between medication classes and incident fall types and were adjusted for relevant covariates.

Results

2,090 participants were included (mean age at baseline 72 years, 53% female). During follow-up, over half of participants (52%, n=1,089) had a fall, with one quarter (25%, n=526) reporting an unexplained fall and almost one fifth (19%, n=394) reporting a fall causing injury. Anti-depressants were associated with an increased risk of falling (OR=3.01, 1.98-4.58, p<0.001), injurious falls (OR=1.96, 1.37-2.81, p<0.001) and unexplained falls (OR=2.71, 1.88-3.91, p<0.001) in fully adjusted models. Anti-cholinergic medications were associated with an increased risk of falling (OR=1.79, 1.11-2.88, p=0.017) and of unexplained falls (OR=1.89, 1.19-3.01, p=0.007). ‘Z’ drugs were associated with an increased risk of falling (OR=2.96, 1.64-5.32, p<0.001) and of injurious falls (OR=2.05, 1.26-3.34, p=0.004). Benzodiazepines and Anti-psychotics were not associated with incident falls in fully adjusted models.

Conclusion

Anti-depressants, anti-cholinergic medications and ‘Z’ drugs are independently associated with an increased falls risk. Given the profound impact falls can have on functional trajectory and quality of life, regular review of ongoing need for these medications should be central to the comprehensive geriatric assessment.

105 EVALUATION OF A NEW PHYSIOTHERAPY-LED VESTIBULAR SERVICE EMBEDDED IN THE FALLS AND SYNCOPE UNIT

Background

Clinical presentations in the falls and syncope unit (FASU) are diverse and require a range of skillsets. Vestibular disorders amount to a significant proportion of presentations. In our FASU, we embedded a 0.5 FTE specialist physiotherapist with expertise in vestibular disorders to work alongside medical and nursing staff. We conducted a service evaluation of the activity of this new service.

Methods

Retrospective Service Evaluation Approval was granted by our Research & Innovation Office. Pseudonymised data was collected corresponding to all new FASU physiotherapy service attendances between August 2021 and May 2022. Descriptive statistics were complemented by a binary logistic regression model to establish independent predictors of more than one physiotherapy session being required over the period.

Results

There were 104 episodes recorded by the new service, corresponding to 101 unique patients. Mean age was 67.7 (SD 19.0, range 17-93), and 73.1% were women. 67% were treated and discharged in 1 session. On average, patients had had a mean of 2 falls prior to the consultation (range 0-25). 28.8% were using a walking aid, and 54.8% self-reported fear of falling. 25% of the referrals to the service were due to suspected vestibular disorders, 62% of which were directly treated by the physiotherapy service. The logistic regression model adjusting by age, sex, use of walking aid, number of falls, and fear of falling showed that only referral for vestibular disorder was an independent predictor of patients needing more than 1 physiotherapy treatment (OR 3.91, 95% CI 1.32-11.58, P=0.014).

Conclusion

Vestibular disorders are common in FASU, and a majority can be treated by a specialist physiotherapy service. Repeated vestibular maneuvers are often needed in such patients. A responsive, embedded physiotherapy service in FASU can directly address this need and further evaluation will focus on the impact of this service on avoidance of ED attendances.

347 LONELINESS AMONGST OLDER INPATIENTS IN THE CONTEXT OF COVID-RELATED VISITING RESTRICTIONS

Background

Loneliness can affect people at all stages of life, but appears to be more closely linked to adverse health outcomes such as quality of life and healthcare use amongst older people. There are concerns that restrictions on hospital visits due to infection control policies related to the COVID-19 pandemic may exacerbate loneliness amongst older inpatients. The aim of this study is to quantify the burden of loneliness amongst older inpatients on a specialist geriatric medicine unit.

Methods

The study site is a large urban university teaching hospital with a 150-bed specialist geriatric medicine unit, comprising acute medical, rehabilitation and long-stay wards. The University of California, Los Angeles (UCLA) Scale was used to measure symptoms of loneliness with scores≥43 indicating high levels of loneliness.

Results

Over 84% of patients were lonely at some time while in hospital, with over one-third (24/76) reporting high levels of loneliness. The mean number of days since last visit from a relative or friend for patients reporting high degrees of loneliness was 11.4 (1.2 – 21.6) days, compared to 5.2 (3.2 – 7.1) days for those with reporting lower levels or no loneliness, though confidence intervals overlapped (p = 0.108). Similarly, patients with higher levels of loneliness had a longer length of stay (68.2 (49.4 – 87.1) compared to 47.9 (33.1 – 62.6) but again findings did not reach significance (p = 0.098). Linear regression models, controlling for competing covariates, found that depressive symptoms, were independently associated with burden of loneliness with a β-Coefficient = 10.69 (5.00 – 16.39).

Conclusion

Loneliness is particularly prevalent amongst older inpatients, with a trend towards higher levels of loneliness in those with less frequent visits. Interventions to help older people stay in touch with family and friends, and maintain social connectedness while in hospital, allowing for COVID-related restrictions, would be welcome, particularly for those with longer lengths of stay.

281 PREVALENCE OF STOPPFALL FALLS-RISK-INCREASING DRUGS (FRIDS) IN PATIENTS PRESENTING TO HOSPITAL WITH A FALL

Background

Falls cause presentation and admission to hospital. Falls-Risk-Increasing-Drugs (FRIDs) are a modifiable risk factor. STOPPFalls criteria was developed, using an expert Delphi panel, to achieve consensus on a comprehensive list of FRIDs. The aim of this study was to identify the prevalence of STOPPFall PRIDs in patients presenting to hospital with falls and identify whether review by a specialist Falls and Syncope Service (FASS) reduces FRIDs.

Methods

This was a retrospective observational study. Patients ≥65 years reviewed by the hospital FASS in the emergency department (over 6-months) and in house (over 2-months), were included. Medication appropriateness at admission and discharge were assessed using STOPPFall criteria. Ethical approval was received from the local research and innovation office (ref7013).

Results

Of 156 patients, 87(55.8%) were ≥65 years; 46% female, mean age 78.1(SD7.5) years. The mean number of conditions was 4(SD4.4); the mean number of regular medications was 6.9(SD4.5). Reasons for referral to FASS included falls (34.5%), dizziness/near fall (35.6%), and transient loss of consciousness (29.9%). For 21.8% there was an associated injury; 11.5% a fracture. Thirty-seven (42.5%) had experienced at least one fall in the previous 12-months.

Sixty-four (73.6%) were on ≥1 STOPPFall FRID. The most common STOPPFall FRID prescribed to older adults were diuretics (24.1%), anti-depressants (20.7%) and benzodiazepines/benzodiazepine-related drugs (13.8%). At least 1 STOPPFall FRID was stopped in 31.3%. The most commonly deprescribed STOPPFall FRIDs were diuretics (20%), alpha blockers (6%) and benzodiazepines/benzodiazepine-related drugs (4.7%). Adults <65years (n=69) were more likely to be prescribed a STOPPFall FRID at admission than older adults (≥65years); 88.4% vs 73.6%, p=0.021.

Conclusion

STOPPFall FRIDs are prevalent in fallers of all ages. Even one review by a specialist FASS leads to medication optimization. The effectiveness of STOPPFalls criteria in the prevention of falls should be evaluated further in intervention studies.

273 ‘HOME ON TIME’: MULTIDISCIPLINARY INTERVENTION REDUCES LENGTH OF STAY AND DELAYS IN CARE TRANSFERS ON AN ACUTE GERIATRIC MEDICINE WARD

Background

Unnecessarily prolonged hospital admission can have a profound effect on a frail, older person’s confidence, mood, functional status and cognition.This study examined whether a structured multidisciplinary intervention, embedded within an acute geriatric medicine ward, could reduce unnecessary days in hospital for acutely unwell older patients.

Methods

The study site is a 28-bed acute geriatric medicine ward in a large urban teaching hospital; data was collected from 1/1/22 to 11/4/22. Patients aged ≥70 years and admitted to the ward were randomly allocated to the Home On Time (HOT) Pathway (n=50) or usual care (n=100). All patients were cared for by a specialist geriatric team. The HOT Pathway involved daily multidisciplinary team (physiotherapy, nursing, occupational therapy, social work and medical) huddles focusing on enhanced communication, early discharge planning and identification of barriers to discharge home. Huddles typically lasted for <15 minutes.

Results

Almost two-thirds (92/150) of the study sample (mean age 83 years, 60% female) were discharged directly from the ward while one-fifth (29/150) were transferred for rehabilitation and one-tenth ultimately to long term care (16/150). The average acute ward Length-of-Stay (LOS) for HOT pathway patients was 10.4 days, compared to 14.4 days for usual care. The average LOS for HOT pathway patients discharged directly home (i.e. not via rehabilitation or to long-term care) was 8.0 days, compared to 10.2 days for usual care. One-fifth (10/50) of HOT pathway patients were discharged home within 48 hours of admission compared to one tenth (10/100) of usual care patients.

Conclusion

A structured, multidisciplinary intervention focusing on enhanced communication and early discharge planning within a geriatric medicine ward can reduce length of inpatient stay, delays in transitions of care and increase the rate of discharge home within 48 hours, potentially averting complications related to prolonged hospital admission.

136 DIABETES IS ASSOCIATED WITH IMPAIRED PERIPHERAL AND CEREBRAL HAEMODYNAMIC RESPONSES IN OLDER ADULTS

Background

Diabetes is associated with slower gait speed and adverse brain health outcomes in older adults. However, the putative mechanisms underlying these associations remain poorly explored. One such mechanism is via altered cerebral perfusion, which may represent an important intermediate phenotype in the association between diabetes and slower gait. We assessed the impact of diabetes on peripheral and cerebral haemodynamic responses during active stand as part of The Irish Longitudinal Study of Ageing (TILDA).

Methods

We assessed: (i) peripheral haemodynamic responses (heart rate, blood pressure, cardiac output) using finometry and (ii) Tissue Saturation Index (TSI) using Near-Infrared Spectroscopy (NIRS) during active stand in older adults.

Function-on-scalar regressions were used to model the impact of diabetes on the dynamic response to standing. Subsequently, multivariable linear models were used to model usual gait speed.

Results

Of 3,011 older adults (mean age: 64.2; 55.2% female) completing active stand, diabetes (n =193, 6.4%) was associated with significantly higher heart rate (mean 3.2, s.e. 0.02 bpm), higher cardiac output (mean 0.16, s.e. 0.04 L/min) and lower systolic blood pressure (mean –6.9, s.e. 1.8 mmHg) during standing. Additionally, diabetes was associated with significantly lower TSI from 10 seconds post-stand (mean –1.2%, s.e. 0.49%). Associations persisted following robust covariate adjustment. Diabetes was associated with significantly slower gait speed (-5.3 cm/s, CI (-8.4,-2.1)). In analysing the relationship between cerebral perfusion and gait speed, poorer recovery of TSI at 60-120 seconds post standing was associated with slower gait speed (0.53 cm/s slower gait speed per unit increase in TSI, p = 0.007).

Conclusion

Diabetes is associated with impaired peripheral and cerebral haemodynamic responses in addition to slower gait speed in community-dwelling older adults. Neuro-cardiovascular instability and altered cerebral perfusion may represent an important intermediate phenotype between diabetes and adverse health outcomes in older adults.

343 RIGHT CARE, RIGHT PLACE, RIGHT TIME? WHAT PROPORTION OF ACUTELY-UNWELL OLDER PATIENTS UNDERGO EVIDENCE-BASED COMPREHENSIVE GERIATRIC ASSESSMENT?

Background

There is robust evidence that Comprehensive Geriatric Assessment (CGA) improves outcomes for acutely unwell older people. Relatively little research has examined how this translates to real life clinical settings, however. The aim of this study therefore was to ascertain how many older people admitted to hospital underwent CGA and how this impacted on readmission rates.

Methods

The study site is a large teaching hospital with 150 specialist geriatric medicine beds and ‘specialty-take’ of frail, older people by the geriatric medicine service. Data pertaining to contact with a geriatric medicine service were collected for 400 consecutive ED presentations of patients aged ≥70 years from 1/1/21, as well as Clinical Frailty Scale (CFS) and readmission within 30 days.

Results

Over one-third (139/400, mean CFS 3.7) of patients were discharged home directly from the ED, with the remainder (261/400, mean CFS 4.5) admitted to hospital. Almost-half overall (122/261, mean CFS 4.7) and 58% of those ≥80 years, were admitted under the care of a geriatrician, with 73% (89/122) cared for on a specialist geriatric medicine ward. Of those not admitted under a geriatrician, 10% (13/139) subsequently underwent CGA on a consultation basis. In total, 48% (126/261, mean CFS 3.7) of patients ≥70 years, including one-third of those ≥80 years with a CFS≥5 (36/99), completed their admission without undergoing CGA. Of those ≥80 years with a CFS≥5 who did not receive CGA, readmission within 30 days was 24% compared to 13% for those who underwent CGA.

Conclusion

Patients who underwent CGA were older, with higher levels of frailty. However, one-third of those aged ≥80 years with CFS ≥5 did not undergo CGA and early readmission was higher in this cohort. CGA in the acute setting is a finite resource and it is imperative it is delivered to those who require it most.

327 REVIEW OF ONCOLOGY PATIENTS ADMITTED FROM 2019-2021: DEFINING THE NEED FOR AN ONCO-GERIATRIC SERVICE

Background

With an aging population, there is an increased need to consider older patients for cancer treatment. Involvement of a Comprehensive Geriatric Assessment (CGA) in an oncology workup can help guide cancer treatment and non-pharmacological treatment in older patients. We undertook a retrospective study looking at older patients admitted during their cancer treatment to establish the need for an onco-geriatric service in our hospital.

Methods

All patients over 85 admitted under oncology from 2019-2021 had a retrospective chart review. Patient demographics, indication for admission and discharge destination were collected. Clinical markers, such as total medications, comorbidities and social history were used to generate an overall understanding of the patient’s Clinical Frailty Score (CFS). We then retrospectively implemented a geriatric assessment to see how patients would benefit from a CGA if an onco-geriatric service was implemented in our hospital.

Results

A total of 22 patients over 85 accounted for 33 admissions, with 54.5% female (n=12). The median CFS was 4 (3-5). At time of admission, 90.1% were on concomitant cancer treatment; 41.7 concurrent chemo, 13.6% concurrent RT. The mean patient had conditions 5.61 (SD3.2 and took an average of 9.2 (SD3.7) regular medications. Most admissions (n=18) required at least one consult from another service (54.5%), with palliative care and cardiology having the highest burden of consults at 11 (33%) and 8 (26.7%) respectively. Only 1 patient had a geriatric consult, while another was seen by our Falls and Syncope Unit after a fall leading to admission. Patients following each attendance were discharge home in 75.7% cases (n=25). Hospice (12.1%), convalescence (3%) and nursing home (3%).

Conclusion

We identified multiple areas in which a CGA can improve management of older patients undergoing cancer treatment, including medication rationalisation. We feel that a onco-geriatric service development in our hospital will lead to better patient care for our older population.

345 HOW PREVALENT ARE UNDETECTED DEPRESSIVE SYMPTOMS AMONGST OLDER HOSPITAL INPATIENTS?

Background

Depression in later life can have a profound effect on quality of life, functional independence, healthcare use and early mortality. For multiple reasons however, depression in later life may often go undetected. The aim of this study is to ascertain the point prevalence of depressive symptoms on a specialist geriatric medicine unit, examining the rate of detection of clinically significant symptoms.

Methods

The study site is a large urban university teaching hospital with a 150-bed specialist geriatric medicine unit, comprising acute medical, rehabilitation and long-stay wards. Depressive symptoms were assessed using the Centre for Epidemiological Studies Depression Scale (CES-D) with a score ≥16 indicating significant symptoms. Medical notes were examined for documentation of screening for/assessment of depression since admission. Patients were included if they were aged ≥70 years, a current inpatient and able to give informed consent.

Results

Almost 62% (47/76) of the study sample (Mean age 83 years, 66% female) met criteria for significant depressive symptoms. Almost-half (23/47, 49%) of patients with significant depressive symptoms were screened for depression (either with a structured screening tool, a documented mood assessment or review by psychiatry) while in hospital. The mean length of stay for patients with depressive symptoms who had not yet been screened for depression was 42.7 (23.2 – 62.2) days and over 70% had been in hospital for at least 10 days, with almost two-thirds (15/24, 65%) currently residing on an acute geriatric medicine ward (rather than a rehabilitation or long stay ward).

Conclusion

Our study demonstrates a high burden of depressive symptoms amongst older inpatients, with almost 2 in 3 meeting criteria for clinically significant symptoms. Less than half of those with clinically significant symptoms were screened for depression however, representing an important missed opportunity to identify, and possibly treat, depression.

277 The ‘Bermuda Triangle’ of Orthostatic Hypotension, Cognitive Impairment and Reduced Mobility: Associations with Falls and Fractures in Community-dwelling Older People

Background

Orthostatic Hypotension (OH), cognitive impairment and mobility impairment frequently co-occur in older adults who fall. The aim of this study was to examine the clustering of these three geriatric syndromes and ascertain their longitudinal associations with falls and fractures in a large cohort of community-dwelling older people (≥65 years).

Methods

This study utilized data from Waves 1-5 of TILDA. OH was defined as a drop of ≥20 mmHg in systolic blood pressure when measured after standing from a seated position and/or reporting unsteadiness when getting up from a chair. Cognitive impairment was defined as MMSE ≤24 and/or self-reporting memory as fair or poor. Mobility impairment was defined as 'Timed Up and Go' ≥12 seconds. Logistic regression models, including 3-way interactions, were used to assess the longitudinal associations of the three geriatric syndromes with future falls (explained and unexplained) and fractures.

Results

Of those with at least one geriatric syndrome (993/2108, 47%), over two-thirds (644/993) had any one of the three, one-quarter had any two (261/993) and almost 10% (88/993) had all three syndromes. One-fifth of the study sample had an unexplained fall during follow-up (mean 6.6 years), while one-tenth had a fracture. In fully adjusted models, the cluster of OH, cognitive impairment and mobility impairment was associated with a greater than 4-fold likelihood of unexplained fall (Odds Ratio 4.36 (2.61–7.28); p<0.001) and double the likelihood of incident fracture (Odds Ratio 2.51 (1.27–4.96); p=0.008) during follow-up, when compared to other clusters. There was no association with explained falls.

Conclusion

The ‘Bermuda Triangle’ of co-existing OH, cognitive impairment and mobility impairment, was independently associated with increased risk of future unexplained falls and fractures amongst community-dwelling older people. This simple risk identification scheme may represent an ideal target for multifaceted falls prevention strategies in community-dwelling older adults.

Quantitative analysis of diffraction by liquids using a pink-spectrum X-ray source

A new approach for performing quantitative structure-factor analysis and density measurements of liquids using X-ray diffraction with a pink-spectrum X-ray source is described. The methodology corrects for the pink beam effect by performing a Taylor series expansion of the diffraction signal. The mean density, background scale factor, peak X-ray energy about which the expansion is performed, and the cutoff radius for density measurement are estimated using the derivative-free optimization scheme. The formalism is demonstrated for a simulated radial distribution function for tin. Finally, the proposed methodology is applied to experimental data on shock compressed tin recorded at the Dynamic Compression Sector at the Advanced Photon Source, with derived densities comparing favorably with other experimental results and the equations of state of tin.

168 ANXIETY SYMPTOMS AMONG OLDER PEOPLE DURING THE COVID-19 PANDEMIC: PREVALENCE AND ASSOCIATED FACTORS

Background

There are concerns that the COVID-19 pandemic could lead to a rise in mental health problems including anxiety amongst older people, especially those shielding alone during the pandemic.

The aim of this study therefore is to examine the prevalence of anxiety symptoms during the COVID-19 pandemic amongst older people and clarify factors associated with higher burden of symptoms.

Methods

We analysed data from the COVID-19 study of The Irish Longitudinal Study on Ageing, conducted on over 3,100 community dwelling people aged ≥60 years from July–November 2020.

Anxiety symptoms were measured with the Generalised Anxiety Disorder-7 Questionnaire with a score ≥ 10 indicating moderate–severe anxiety.

Linear regression models were used to assess the association of variables of interest with anxiety symptoms.

Results

Almost 9% of participants (n = 3,128; mean age 71 years) had moderate–severe symptoms of anxiety.

Factors independently associated with a higher burden of anxiety symptoms included female sex (β = 0.60 (0.33–0.87)); living alone (β = 0.72 (0.41–1.02)); ≥2 chronic diseases (β = 0.85 (0.41–1.30); heart disease (β = 0.95 (0.45–1.46)) and reporting frequent loneliness (β = 6.59 (6.03–7.16)). Age ≥ 80 years (β = −0.77 (−1.16—0.37)) and tertiary level education (β = −0.48 (−0.86—-0.10)) were associated with lower anxiety symptom burden.

Conclusion

Almost 1 in 10 of this population-representative sample of older people had moderate to severe anxiety symptoms during the COVID-19 pandemic.

Strategies to address loneliness, which was particularly strongly associated with anxiety symptoms during the pandemic, should be a priority.

165 WHAT FACTORS ARE ASSOCIATED WITH ADVANCED CARE PLANNING IN COMMUNITY-DWELLING OLDER PEOPLE?

Background

Advance Care Planning (ACP) involves expressing wishes regarding your future medical care and/or preferences about your end-of-life in the event of serious illness.

The aim of this study was to clarify the proportion of community-dwelling older people who engage in ACP and what factors are independently associated with ACP.

Methods

Participants aged ≥60 years (n = 4,831, mean age 71 years) at Wave 4 of the Irish Longitudinal Study on Ageing were asked: Have you made your wishes/preferences known about the kind of care that you would like to receive in the event of serious illness? If yes, they were asked if this had been documented informally (family/carers or medical professionals) or formally (by written advanced care plan).

Logistic regression models assessed the association of covariates of interest with ACP.

Results

One quarter of the study sample (1,153/4,831) had an ACP. Only 10% (119/1,153) had ACP documented in writing, while only 2% (27/1,153) had discussed ACP with a healthcare professional.

Age ≥ 80 years (OR 1.63 (1.31–2.02)), female sex (OR 1.58 (1.37–1.83)), higher educational attainment (OR 1.42 (1.18–1.71), poorer self-rated health (OR 1.58 (1.04–2.39) and lower levels of religiosity (OR 1.50 (1.03–2.19) were independently associated with ACP.

Conclusion

While ACP may have benefits in extending autonomy and facilitating decision-making, only 1 in 4 of this population-representative sample of older people had engaged in ACP, with only 1 in 50 having their ACP documented in writing.

Further work is therefore required to educate the public and healthcare professionals regarding the benefits of ACP.

161 THE ROLE OF THE GERIATRIC DAY HOSPITAL DURING THE COVID 19 PANDEMIC

Background

Methods

Results

Conclusion

162 TRENDS IN EMERGENCY DEPARTMENT USE BY OLDER PEOPLE DURING THE COVID-19 PANDEMIC

Background

Older people have been disproportionately affected by the COVID-19 pandemic with reports suggesting that many older people deferred seeking healthcare during the pandemic due to fear of contracting COVID-19.

The aim of this study was to examine trends of emergency department (ED) use by older people during the first wave of the COVID-19 pandemic compared to previous years.

Methods

The study site is a 1,000-bed university teaching hospital with annual ED new-patient attendance of >50,000.

All ED presentations of patients aged ≥70 years from March–August 2020, 2019 and 2018 inclusive (n = 13,989) were reviewed and compared for presenting complaint, Manchester Triage Score, and admission/discharge decision.

Results

There was a 16% reduction in presentations across the 6 months in 2020 compared to the average of 2018/2019. On average 4 fewer people aged ≥70 years presented to the ED per day in 2020.

Much of this was concentrated in March (33% fewer presentations) and April (31% fewer presentations), when the country was in ‘lockdown’, i.e. non-essential journeys were banned.

There was a 20% reduction in patients presenting with stroke and cardiac complaints.

In the three months following easing of restrictions, there was a 25% increase in falls and orthopaedic injuries when compared to 2018/2019.

Conclusion

This study demonstrates a significant decline in the number of older people presenting to the ED for unscheduled care, including for potentially time-dependent illnesses such as stroke or cardiac complaints.

Presenting to the ED remains the most frequent route by which unwell older people access acute hospital care and it is vitally important that they continue to do so in a timely manner when necessary. Given the possibility of further lockdowns and restrictions, this message needs to be communicated to older people clearly by healthcare professionals and governmental bodies to mitigate against adverse outcomes related to delayed or deferred care.

166 HEALTH TRAJECTORIES OF FRAIL, OLDER PEOPLE WHILE COCOONING DURING THE COVID-19 PANDEMIC

Background

Cocooning, i.e. staying at home and reducing interaction with others, was a key part of the strategy to protect older people during the COVID-19 pandemic.

Unfortunately, there are concerns this has had a negative impact on the physical and mental wellbeing of those who have been isolated.

Methods

We completed a survey of 150 patients (55% female, mean age 79.8 years, average Clinical Frailty Scale 4.8) attending ambulatory medical services in a large university hospital.

Questions were focused on: access to healthcare services, mental health, physical health, and attitudes to COVID-19 restrictions.

Results

Almost 40% reported that their mental health was ‘worse’ or ‘much worse’ while cocooning, while over 40% reported a decline in their physical health.

Over 57% had a scheduled healthcare-related visit cancelled while cocooning, most frequently hospital outpatient appointments.

Worryingly, almost 1/6 reported not seeking medical attention for an illness that they would usually. Of these, half did not as they were worried about catching COVID and 46% did not as this service was not currently available to them.

Conclusion

The COVID-19 pandemic and lack of access to essential services, both medical and social, has had a devastating impact on older people.

This is evident in both the acute presentations to hospital and the longer-term impact it has had on health and function.

It is important that in the future clear policies are in place to enable older people to access care when they need it.

171 THE ‘WISH TO DIE’ AMONGST OLDER PEOPLE IN IRELAND IN THE CONTEXT OF THE DYING WITH DIGNITY BILL

Background

‘Wish to Die’ (WTD) involves thoughts of or wishes for one’s own death or that one would be better off dead.

Assisted dying is the act of deliberately providing medical assistance to another person who wishes to end their own life. Currently, in Ireland, it is illegal to provide such assistance to people with WTD or suicidal ideation. However, a new bill that would legalise assisted dying for those with terminal illnesses, the Dying with Dignity Bill 2020, is due to be considered by lawmakers in Ireland in the coming months.

In order to inform discussion around this complex issue, we examine the prevalence and longitudinal course of WTD in a large population-representative sample of older people.

Methods

To define WTD, participants were asked: ‘In the last month, have you felt that you would rather be dead?’

Depressive symptoms were measured using the CES-D.

Mortality data were compiled by linking administrative death records to individual-level survey data from the study.

Results

At Wave 1, 3.5% of participants (279/8,174) reported WTD. Both persistent loneliness (OR 5.73 (95% CI 3.41–9.64)) and depressive symptoms (OR 6.12 (95% CI 4.33–8.67)) were independently associated with WTD.

Of participants who first reported WTD at Wave 1 or 2, 72% did not report WTD when reassessed after 2 years, and the prevalence of depressive symptoms (−44%) and loneliness (−19%) was more likely to decline in this group at follow-up.

Fifteen per cent of participants expressing WTD at Wave 1 died during a 6-year follow-up.

Conclusion

WTD amongst community-dwelling older people is frequently transient and is strongly linked with the course of depressive symptoms and loneliness.

An enhanced focus on improving access to mental health care and addressing social isolation in older people should therefore be a public health priority, particularly in the current context of the Covid-19 pandemic.

163 EVALUATING THE ROLE OF THE GERIATRIC DAY HOSPITAL IN MEDICATION OPTIMISATION

Background

The geriatric day hospital (GDH) provides outpatient geriatric medical, nursing and rehabilitation care to older adults. The aim of this study was to assess whether medication optimisation occurs in this setting. We believe the GDH would be an ideal location for mediation optimisation due to the stable community dwelling patients and close follow up by specialised physicians.

Methods

Electronic patient records of the new patients ≥65 years seen in the GDH over a 3-month period were reviewed. Potentially inappropriate prescriptions (PIPs) and potentially prescribing omissions (PPOs) were identified using the STOPP/START prescribing tool on admission to the GDH and again at discharge from the GDH.

Results

One-hundred and sixty-seven patient records were reviewed; mean age 80.8 (SD6.5) years, 62.9% female, median clinical frailty scale score 6 (IQR5–6), mean number of conditions 5.79 (SD3), mean number of medications 7.57 (SD3.7). Patients had a median of 4 (IQR2–7) consultations. The number of patients prescribed at least 1 STOPP-PIP reduced by 10% (42.4% vs 38%; p < 0.001). Vasodilator drugs in patients with orthostatic hypotension were deprescribed most frequently (6.5% vs 3%; p < 0.001). PPOs were reduced by 36% (47.5% vs 30.6%;p < 0.001). The largest improvement was identified in the prescription of vitamin D in patients experiencing falls (17.4% vs 13.8%;p < 0.001). Logistic regression was performed to ascertain the influence of age, gender, falls, dementia, co-morbidity number and medication number on the likelihood of a patient experiencing a PIP or PPO. For every medication prescribed, the odds of experiencing a PIP increased by 11.8% (OR1.187, 95%CI 1.052–1.339). Being female increased the odds of experiencing a PPO by 21.7% (OR2.17, 95%CI 10.53–4.468).

Conclusion

Medication optimisation is key in avoiding side effects from potentially inappropriate medications. The frequency of patient attendances coupled with geriatricians’ expertise makes the GDH an ideal setting for medication optimisation in multi-morbid frail community-dwelling older adults.

138 DELAYED BLOOD PRESSURE RECOVERY AFTER STANDING INDEPENDENTLY PREDICTS FRACTURE IN COMMUNITY-DWELLING OLDER PEOPLE

Background

Orthostatic hypotension, characterized by delayed blood pressure recovery (DBPR) after standing, is a risk factor for falls but the longitudinal relationship with fracture is not yet known. The aim of this study was to examine the prospective risk of fracture associated with DBPR.

Methods

This study, embedded within the Irish Longitudinal Study on Ageing (TILDA), examined prospective risk of fracture (hip, wrist or vertebral) associated with DBPR at 8-year follow-up in a population-representative sample of more than 3,000 (54% female) community-dwelling older people. Orthostatic blood pressure (BP) was measured using a finometer during active stand at TILDA Wave 1. DBPR was defined as systolic BP ≤ 20 mmHg lower and/or diastolic BP ≤ 10 mmHg from baseline value at 30, 60 and 90 seconds after standing. Participants with a fracture reported at any of Waves 2–5 were defined as having ‘Incident Fracture’. Logistic regression models were used to estimate odds ratios (ORs) for the association between DBPR and incident fracture.

Results

Seven percent (212/3117) of participants sustained a fracture during follow-up. DBPR at 30 seconds was a significant predictor of any fracture [OR 1.80, 95% confidence interval (CI) 1.28–2.53] and hip fracture (OR 4.44, 95% CI 2.03–9.71) in fully adjusted models. DBPR at 30 seconds did not predict wrist or vertebral fracture. DBPR at 60 seconds also predicted any fracture (OR 1.74, 95% CI 1.19–2.54) and hip fracture (OR 4.66, 95% CI 2.12–10.26) whereas DBPR at 90 seconds predicted any (OR 1.99, 95% CI 1.38–2.87), wrist (OR 1.87, 95% CI 1.19–2.95), and hip fracture (OR 3.39, 95% CI 1.45–7.93) in fully adjusted models.

Conclusion

Delayed BP recovery independently predicts fracture in community-dwelling older people, is potentially modifiable, and can be measured in an ambulatory setting. Given the morbidity and mortality associated with fractures, identification of such risk factors is crucial in order to inform preventative strategies.

239 IS ORTHOSTATIC HYPOTENSION ASSOCIATED WITH ALTERED CEREBRAL PERFUSION DURING ACTIVE STANDING?

Background

Orthostatic Hypotension (OH) is associated with poor health outcomes in later life including depression, cognitive impairment, frailty and falls. Whilst it is hypothesised that OH compromises cerebral autoregulation leading to hypoperfusion, this has not been robustly demonstrated to date. This study investigated the association between OH and cerebral perfusion during orthostasis using a non-invasive surrogate of cerebral perfusion, Near Infrared Spectroscopy (NIRS).

Methods

Four hundred and ninety one participants (58% female, median age 65, IQR 38–92) attending a falls and syncope service underwent measurement of beat-to-beat blood pressure (BP) by finometry and real-time frontal lobe perfusion (% TSI: Tissue Saturation Index) by NIRS during the active stand manoeuvre. We examined the association between OH and change in cerebral perfusion (delta TSI) using mixed-effects linear regression, with adjustment for important clinical covariates.

Results

Nearly two-fifths of the sample (189/491,38.5%) met criteria for OH occurring between 30 and 120 seconds after standing. Using mixed effects linear regression models, we observed a significant relationship between OH and TSI at the same timepoint (β −0.53, −0.59 to −0.46, p < 0.001) which persisted following adjustment for confounders including age, sex, baseline blood pressure, cerebrovascular and cardiovascular disease, depression/anxiety, diabetes, systolic blood pressure, antihypertensives, and antidepressants (β −0.51, −0.58 to −0.44, p < 0.001). Cerebral perfusion levels differed for those with OH compared to those without.

Conclusion

OH is independently associated with lower frontal lobe cerebral perfusion. This association may indicate disruption to dynamic cerebral autoregulation and explain the significant link between OH and poor health outcomes.

216 IMPROVING INPATIENT INFLUENZA VACCINATION RATES—THE VALUE OF AN ELECTRONIC PATIENT RECORD REMINDER SYSTEM

Background

Influenza vaccination, particularly for vulnerable, older adults, will have added importance this winter given the possibility of further waves of COVID-19 pandemic. Previous interventions at the study site noted poor awareness on the need for inpatient Influenza vaccination¹. This study examines a vaccination reminder process using an electronic patient record (EPR) to identify high-priority eligible inpatients.

Methods

The study site is a 900-bed university teaching hospital with all clinical notes accessed via an EPR.

We included a convenience sample of 750 adults aged≥50 years (mean age 75.9 +/− 0.4 years, 48% female) and high-priority for influenza vaccination (Age > 65 years and/or length of stay (LOS) >30 days) from October 1^st 2020 to January 12^th 2021.

A live electronic dashboard identified eligible inpatients for vaccination, prompting vaccination reminders to the clinical teams via the antimicrobial pharmacist.

Data was collected retrospectively. Logistic regression models reporting odds ratios were used to assess the association of these reminders with vaccine uptake.

Results

Over one third (35%, 264/750) of high-priority patients received the Influenza vaccine while inpatients, including 40% aged ≥80 years.

The reminder was sent on 41% (305/750) of patients and was associated with an almost 50% higher likelihood of vaccination after adjusting for other covariates (Odds Ratio 1.48 (95% CI 1.00–2.20); p = 0.048).

Other factors independently associated with vaccination were advancing age (Odds Ratio 2.69 (95% CI 1.12–6.47) for age ≥ 80 years); LOS (4% higher likelihood of vaccination for every additional day in hospital) and admission under geriatric medicine (Odds Ratio 3.71 (95% CI 2.45–5.62) when compared to other specialities).

Conclusion

Our study shows relatively low uptake of inpatient Influenza vaccination and strategies to improve uptake are required. Reminders sent to clinical teams using the EPR appear to be an effective means of increasing Influenza vaccination and should be considered as part of this year’s inpatient vaccination drive.

Physical and mental health of older people while cocooning during the COVID-19 pandemic

BACKGROUND

Cocooning or shielding, i.e. staying at home and reducing face-to-face interaction with other people, was an important part of the response to the COVID-19 pandemic for older people. However, concerns exist regarding the long-term adverse effects cocooning may have on their physical and mental health.

AIM

To examine health trajectories and healthcare utilization while cocooning in a cohort of community-dwelling people aged ≥70 years.

DESIGN

Survey of 150 patients (55% female, mean age 80 years and mean Clinical Frailty Scale Score 4.8) attending ambulatory medical services in a large urban university hospital.

METHODS

The survey covered four broad themes: access to healthcare services, mental health, physical health and attitudes to COVID-19 restrictions. Survey data were presented descriptively.

RESULTS

Almost 40% (59/150) reported that their mental health was 'worse' or 'much worse' while cocooning, while over 40% (63/150) reported a decline in their physical health. Almost 70% (104/150) reported exercising less frequently or not exercising at all. Over 57% (86/150) of participants reported loneliness with 1 in 8 (19/150) reporting that they were lonely 'very often'. Half of participants (75/150) reported a decline in their quality of life. Over 60% (91/150) agreed with government advice for those ≥70 years but over 40% (61/150) reported that they disliked the term 'cocooning'.

CONCLUSIONS

Given the likelihood of further restrictions in coming months, clear policies and advice for older people around strategies to maintain social engagement, manage loneliness and continue physical activity and access timely medical care and rehabilitation services should be a priority.

Novel experimental setup for megahertz X-ray diffraction in a diamond anvil cell at the High Energy Density (HED) instrument of the European X-ray Free-Electron Laser (EuXFEL)

The high-precision X-ray diffraction setup for work with diamond anvil cells (DACs) in interaction chamber 2 (IC2) of the High Energy Density instrument of the European X-ray Free-Electron Laser is described. This includes beamline optics, sample positioning and detector systems located in the multipurpose vacuum chamber. Concepts for pump-probe X-ray diffraction experiments in the DAC are described and their implementation demonstrated during the First User Community Assisted Commissioning experiment. X-ray heating and diffraction of Bi under pressure, obtained using 20 fs X-ray pulses at 17.8 keV and 2.2 MHz repetition, is illustrated through splitting of diffraction peaks, and interpreted employing finite element modeling of the sample chamber in the DAC.

X-ray Free Electron Laser-Induced Synthesis of ε-Iron Nitride at High Pressures

The ultrafast synthesis of ε-Fe₃N_1+x in a diamond-anvil cell (DAC) from Fe and N₂ under pressure was observed using serial exposures of an X-ray free electron laser (XFEL). When the sample at 5 GPa was irradiated by a pulse train separated by 443 ns, the estimated sample temperature at the delay time was above 1400 K, confirmed by in situ transformation of α- to γ-iron. Ultimately, the Fe and N₂ reacted uniformly throughout the beam path to form Fe₃N_1.33, as deduced from its established equation of state (EOS). We thus demonstrate that the activation energy provided by intense X-ray exposures in an XFEL can be coupled with the source time structure to enable exploration of the time-dependence of reactions under high-pressure conditions.

Impact of a specialist service in the Emergency Department on admission, length of stay and readmission of patients presenting with falls, syncope and dizziness

BACKGROUND

Up to half of patients presenting with falls, syncope or dizziness are admitted to hospital. Many are discharged without a clear diagnosis for their index episode, however, and therefore a relatively high risk of readmission.

AIM

To examine the impact of ED-FASS (Emergency Department Falls and Syncope Service) a dedicated specialist service embedded within an ED, seeing patients of all ages with falls, syncope and dizziness.

DESIGN

Pre- and post-cohort study.

METHODS

Admission rates, length of stay (LOS) and readmission at 3 months were examined for all patients presenting with a fall, syncope or dizziness from April to July 2018 (pre-ED-FASS) inclusive and compared to April to July 2019 inclusive (post-ED-FASS).

RESULTS

There was a significantly lower admission rate for patients presenting in 2019 compared to 2018 [27% (453/1676) vs. 34% (548/1620); X2 = 18.0; P < 0.001], with a 20% reduction in admissions. The mean LOS for patients admitted in 2018 was 20.7 [95% confidence interval (CI) 17.4-24.0] days compared to 18.2 (95% CI 14.6-21.9) days in 2019 (t = 0.98; P = 0.3294). This accounts for 11 344 bed days in the 2018 study period, and 8299 bed days used after ED-FASS. There was also a significant reduction in readmission rates within 3 months of index presentation, from 21% (109/1620) to 16% (68/1676) (X2 = 4.68; P = 0.030).

CONCLUSION

This study highlights the significant potential benefits of embedding dedicated multidisciplinary services at the hospital front door in terms of early specialist assessment and directing appropriate patients to effective ambulatory care pathways.

The cross-sectional association between diabetes and orthostatic hypotension in community-dwelling older people

AIMS

Orthostatic hypotension is a recognized complication of diabetes, but studies examining prevalence in diabetes are limited. The aim of this study was to ascertain the prevalence of orthostatic hypotension and the pattern of orthostatic BP response in a cohort of people with diabetes aged ≥ 50 years, embedded within the Irish Longitudinal Study of Ageing.

METHODS

Orthostatic hypotension was defined as a drop in systolic blood pressure (SBP) ≥ 20 mmHg or drop in diastolic blood pressure (DBP) ≥ 10 mmHg at 30 s after standing. Diabetes was defined by self-report but cross-checked against HbA_1c and medication records. Multilevel mixed effects linear regression models were used to compare orthostatic BP in people with and without diabetes.

RESULTS

Some 3222 people were included, 7% (213 of 3222) of whom had diabetes. Prevalence of orthostatic hypotension in the group with diabetes was 22% (46 of 213) vs. 13% in those without diabetes; χ² = 12.43; P < 0.001. Multilevel models demonstrated prolonged recovery of DBP in people with diabetes, with only 41% (87 of 213) returning to baseline by 60 s. Logistic regression models demonstrated that diabetes was associated with a significantly increased likelihood of orthostatic hypotension (odds ratio 1.84, 95% confidence interval 1.30-2.59; P = 0.001) and this remained robust after controlling for covariates.

CONCLUSION

Over one-fifth of older people with diabetes had orthostatic hypotension. Recovery of DBP is related to dynamic changes in total peripheral resistance and impairment of this baroreflex-mediated response may explain the higher prevalence in diabetes. Given the prognostic implications when co-existing with diabetes, orthostatic hypotension may represent a potentially modifiable risk factor for adverse outcomes in late-life diabetes.

Non-pharmacological interventions for cognition in patients with Type 2 diabetes mellitus: a systematic review

Midlife Type II diabetes mellitus (T2DM) is an important yet often unrecognized risk factor for the later development of dementia. We conducted a systematic review to assess the efficacy of non-pharmacological interventions (namely diet, exercise and cognitive training) for T2DM on cognition. A search strategy was constructed and applied to four databases: EMBASE, Medline, CINAHL and Web of Science. Peer-reviewed journal articles in English were considered assessing the effect of exercise, dietary or cognitive training/stimulation-based interventions (or any combination of these) in patients with T2DM on cognition. Results were dual-screened and extracted by two independent reviewers. Of 4820 results, 3782 remained after de-duplication. Forty full-texts were screened and two studies were included in the final review. The first assessed the impact of a 10-year intensive lifestyle intervention on T2DM-related complications (Look-AHEAD study) and the second was a post hoc analysis of T2DM patients from a trial of a physical activity intervention in older non-demented adult with functional limitations (LIFE study). Whilst the Look-AHEAD study found no impact on diagnosis of mild cognitive impairment or dementia, the LIFE study demonstrated beneficial effects on global cognitive function and delayed memory specifically in older adults with T2DM. There is insufficient evidence to fully assess the effect of non-pharmacological interventions on cognition in T2DM. Well-constructed trials must be designed to specifically assess the effect of non-pharmacological and multi-domain interventions for cognition in patients with T2DM in midlife. All trials examining interventions in T2DM should consider cognition as at least a secondary outcome.

The Influence of Mitochondria Enzyme Activity on Beef Tenderness

ObjectivesAmong all eating quality attributes, tenderness is often described as the most important factor dictating the overall acceptance of cooked beef, as well as, future decision to repeat purchase. While many intrinsic and extrinsic factors impact end-product tenderness, variation in tenderness is usually attributed to the extent of postmortem proteolysis occurring during meat aging. Evidence from the literature indicates that muscle fiber type composition is a major source of variation in the rate and extent of postmortem proteolysis. One of the major differences that distinguishes muscle fibers is the content of mitochondria. Typically, red muscle (slow-oxidative) is characterized by greater amounts of mitochondria than white muscle (fast-glycolytic). As part of the calcium buffering system, mitochondria sequester large quantities of calcium to maintain a constant cytosolic calcium level. We hypothesized that mitochondria may delay the activation of µ-calpain, the major protease responsible for postmortem proteolysis, through preventing the increase in cytosolic calcium concentration.Materials and MethodsTo test our hypothesis, beef longissimus thoracis muscle samples were collected at 30 min and 16 d postmortem. The 30 min samples were immediately snap frozen in liquid nitrogen and stored at – 80°C, while the 16 d samples were used to determine Warner-Bratzler shear force (WBSF) values. Based on WBSF values, the samples were allocated into less tender (average WBSF = 5.3 kg; n = 8) or more tender (average WBSF = 2.3 kg; n = 8) categories. Succinate dehydrogenase (SDH) abundance, citrate synthase (CS) activity, phosphofructokinase (PFK) activity, and glycogen phosphorylase (GP) activity were compared between the two categories using the 30 min samples. Collected data were analyzed using a Student’s t test and considered significant at P ≤ 0.05.ResultsOur results showed that SDH abundance and CS activity (mitochondrial biomarkers) were significantly greater (P = 0.01 and 0.003, respectively) in less tender samples when compared to more tender samples. On the other hand, PFK and GP activities (glycolytic biomarkers) were greater (P < 0.05) in the more tender than less tender steaks.ConclusionWhile not a cause and effect relationship, these data indicate that mitochondria content likely plays a role in development of beef tenderness.

Measurement of Body-Centered Cubic Gold and Melting under Shock Compression

We combined laser shock compression with in situ x-ray diffraction to probe the crystallographic state of gold (Au) on its principal shock Hugoniot. Au has long been recognized as an important calibration standard in diamond anvil cell experiments due to the stability of its face-centered cubic (fcc) structure to extremely high pressures (P >600  GPa at 300 K). This is in contrast to density functional theory and first principles calculations of the high-pressure phases of Au that predict a variety of fcc-like structures with different stacking arrangements at intermediate pressures. In this Letter, we probe high-pressure and high-temperature conditions on the shock Hugoniot and observe fcc Au at 169 GPa and the first evidence of body-centered cubic (bcc) Au at 223 GPa. Upon further compression, the bcc phase is observed in coexistence with liquid scattering as the Hugoniot crosses the Au melt curve before 322 GPa. The results suggest a triple point on the Au phase diagram that lies very close to the principal shock Hugoniot near ∼220  GPa.

Identification of Phase Transitions and Metastability in Dynamically Compressed Antimony Using Ultrafast X-Ray Diffraction

Ultrafast x-ray diffraction at the LCLS x-ray free electron laser has been used to resolve the structural behavior of antimony under shock compression to 59 GPa. Antimony is seen to transform to the incommensurate, host-guest phase Sb-II at ∼11  GPa, which forms on nanosecond timescales with ordered guest-atom chains. The high-pressure bcc phase Sb-III is observed above ∼15  GPa, some 8 GPa lower than in static compression studies, and mixed Sb-III/liquid diffraction are obtained between 38 and 59 GPa. An additional phase which does not exist under static compression, Sb-I^{'}, is also observed between 8 and 12 GPa, beyond the normal stability field of Sb-I, and resembles Sb-I with a resolved Peierls distortion. The incommensurate Sb-II high-pressure phase can be recovered metastably on release to ambient pressure, where it is stable for more than 10 ns.

Classification of cocaine-dependent participants with dynamic functional connectivity from functional magnetic resonance imaging data

Static functional connectivity (FC) analyses based on functional magnetic resonance imaging (fMRI) data have been extensively explored for studying various psychiatric conditions in the brain, including cocaine addiction. A recently emerging, more powerful technique, dynamic functional connectivity (DFC), studies how the FC dynamics change during the course of the fMRI experiments. The aim in this paper was to develop a computational approach, using a machine learning framework, to determine if DFC features were more successful than FC features in the classification of cocaine-dependent patients and healthy controls. fMRI data were obtained from of 25 healthy and 58 cocaine-dependent participants while performing a motor response inhibition task, stop signal task. Group independent component analysis was carried out on all participant data to compute spatially independent components (ICs). Eight ICs were selected manually as relevant brain networks, which were used to classify healthy versus cocaine-dependent participants. FC and DFC measures of the chosen IC pairs were used as features for the classification algorithm. Support Vector Machines were used for both feature selection/reduction and participant classification. Based on DFC with only seven IC pairs, participants were successfully classified with 95% accuracy (and with 90% accuracy with three IC pairs), whereas static FC yielded only 81% accuracy. Visual, sensorimotor, default mode, and executive control networks, amygdala, and insula played the most significant role in the DFC-based classification. These findings support the use of DFC-based classification of fMRI data as a potential biomarker for the identification of cocaine dependence.

Ferrous Iron Under Oxygen-Rich Conditions in the Deep Mantle

Recent experiments have demonstrated the existence of previously unknown iron oxides at high pressure and temperature including newly discovered pyrite-type FeO2 and FeO2Hx phases stable at deep terrestrial lower mantle pressures and temperatures. In the present study, we probed the iron oxidation state in high-pressure transformation products of Fe3+OOH goethite by in situ X-ray absorption spectroscopy in laser-heated diamond-anvil cell. At pressures and temperatures of ~91 GPa and 1,500-2,350 K, respectively, that is, in the previously reported stability field of FeO2Hx, a measured shift of -3.3 ± 0.1 eV of the Fe K-edge demonstrates that iron has turned from Fe3+ to Fe2+. We interpret this reductive valence change of iron by a concomitant oxidation of oxygen atoms from O2- to O-, in agreement with previous suggestions based on the structures of pyrite-type FeO2 and FeO2Hx phases. Such peculiar chemistry could drastically change our view of crystal chemistry in deep planetary interiors.

Observation of the shock-induced β-Sn to b.c.t.-Sn transition using time-resolved X-ray diffraction

Time-resolved X-ray diffraction measurements have been carried out on dynamically compressed Sn up to a maximum pressure of ∼13 GPa at the European Synchrotron Radiation Facility. The phase transition from β-Sn to body-centered tetragonal (b.c.t.) Sn has been observed using synchrotron X-ray diffraction for the first time undergoing shock compression and release. Following maximum compression, the sample releases to lower pressures for several nanoseconds until the reverse transition occurs. The data are in good agreement with previous shock boundaries that indicate that the β-Sn phase is stable ∼2 GPa higher than the static boundary upon compression and the b.c.t.-Sn phase is stable ∼1 GPa lower upon release. The transition to the high-pressure phase reveals a loss of texture in the X-ray diffraction data from the `quasi' single-crystal β-Sn structure to a more powder-like Debye-Scherrer ring.

Femtosecond diffraction studies of solid and liquid phase changes in shock-compressed bismuth

Bismuth has long been a prototypical system for investigating phase transformations and melting at high pressure. Despite decades of experimental study, however, the lattice-level response of Bi to rapid (shock) compression and the relationship between structures occurring dynamically and those observed during slow (static) compression, are still not clearly understood. We have determined the structural response of shock-compressed Bi to 68 GPa using femtosecond X-ray diffraction, thereby revealing the phase transition sequence and equation-of-state in unprecedented detail for the first time. We show that shocked-Bi exhibits a marked departure from equilibrium behavior - the incommensurate Bi-III phase is not observed, but rather a new metastable phase, and the Bi-V phase is formed at significantly lower pressures compared to static compression studies. We also directly measure structural changes in a shocked liquid for the first time. These observations reveal new behaviour in the solid and liquid phases of a shocked material and give important insights into the validity of comparing static and dynamic datasets.

Screening for frailty in older emergency department patients: the utility of the Survey of Health, Ageing and Retirement in Europe Frailty Instrument

BACKGROUND

Greater numbers of older patients are accessing hospital services. Specialist geriatric input at presentation may improve outcomes for at-risk patients. The Survey of Health, Ageing and Retirement in Europe Frailty Instrument (SHARE-FI) frailty measure, developed for use in the community, has also been used in the emergency department (ED).

AIM

To measure frailty, review its prevalence in older patients presenting to ED and compare characteristics and outcomes of frail patients with their non-frail counterparts.

DESIGN

Patient characteristics were recorded using symphony® electronic data systems. SHARE-FI assessed frailty. Cognition, delirium and 6 and 12 months outcomes were reviewed.

METHODS

A prospective cohort study was completed of those aged ≥70 presenting to ED over 24 h, 7 days a week.

RESULTS

Almost half of 198 participants (46.7%, 93/198) were classified as frail, but this was not associated with a significant difference in mortality rates (OR 0.89, 95% CI 0.58-1.38, P = 0.614) or being alive at home at 12 months (OR 1.07, 95% CI 0.72-1.57, P = 0.745). Older patients were more likely to die (OR 2.34, 95% CI 1.30-4.21, P = 0.004) and less likely to be alive at home at 12 months (OR 0.49, 95% CI 0.23-0.83, P = 0.009). Patients with dementia (OR 0.24, P = 0.005) and on ≥5 medications (OR 0.37, 95% CI 0.16-0.87, P = 0.022) had a lower likelihood of being alive at home at 12 months.

CONCLUSIONS

Almost half of the sample cohort was frail. Older age was a better predictor of adverse outcomes than frailty as categorized by the SHARE-FI. SHARE-FI has limited predictability when used as a frailty screening instrument in the ED.

Straight-to-test colonoscopy for 2-week-wait referrals improves time to diagnosis of colorectal cancer and is feasible in a high-volume unit

AIM

We have introduced 'straight-to-test' (STT) colonoscopy as part of our 2-week-wait (2WW) pathway to address increasing numbers of urgent referrals for colorectal cancer (CRC) within the National Health Service. In this study we evaluated the ability of this initiative to shorten the time to diagnosis of CRC.

METHOD

We amended our 2WW referral form to include performance status and comorbidities. General practitioners were asked to provide data on estimated glomerular filtration rate and full blood count/ferritin. Our 2WW referrals were screened by a colorectal consultant and a nurse specialist. Those deemed unsuitable for STT were offered outpatient assessment (OPA).

RESULTS

Of 553 2WW referrals screened, 352 were considered suitable, 65 of whom failed a telephone assessment or were uncontactable, and accordingly 287 were offered the STT pathway. The STT group was significantly younger than the OPA group (median 65.9 years vs 78.7 years; P < 0.0001). STT colonoscopy significantly reduced the time to first test (13 days vs 22 days; P < 0.0001) and tissue diagnosis from the referral date (17 days vs 24.5 days; P < 0.0001). Thirty-seven (6.8%) CRCs were detected. Proportionately fewer patients in the STT pathway were managed with 'best supportive care only' compared with patients attending OPA (one of 15 vs six of 22, respectively). STT colonoscopy obviated the need for clinic attendance before testing in 287 patients, representing a potential net cost benefit of at least £48 500 in 4 months.

CONCLUSION

STT colonoscopy was safe and effective for selecting out a group of symptomatic patients who could proceed straight to endoscopic examination and receive a diagnosis more rapidly.

Investigation and diagnostic formulation in patients admitted with transient loss of consciousness

Several commonly completed tests have low diagnostic yield in the setting of transient loss of consciousness (T-LOC). We estimated the use and cost of inappropriate investigations in patients admitted with T-LOC and assessed if these patients were given a definitive diagnosis for their presentation. We identified 80 consecutive patients admitted with T-LOC to a university teaching hospital. Eighty-eight percent (70/80) had a computerized topography (CT) brain scan and 49% (34/70) of these scans were inappropriate based on standard guidelines. Almost half (17/80) of electroencephalograms (EEG) and 82% (9/11) of carotid doppler ultrasound performed were not based on clinical evidence of seizure or stroke respectively. Forty-four percent (35/80) of patients had no formal diagnosis documented for their presentation. Inappropriate investigation in T-LOC is very prevalent in the acute hospital, increasing cost of patient care. In addition, there is poor diagnostic formulation for T-LOC making recurrent events more likely in the absence of definitive diagnoses.

Ultrafast X-Ray Diffraction Studies of the Phase Transitions and Equation of State of Scandium Shock Compressed to 82 GPa

Using x-ray diffraction at the Linac Coherent Light Source x-ray free-electron laser, we have determined simultaneously and self-consistently the phase transitions and equation of state (EOS) of the lightest transition metal, scandium, under shock compression. On compression scandium undergoes a structural phase transition between 32 and 35 GPa to the same bcc structure seen at high temperatures at ambient pressures, and then a further transition at 46 GPa to the incommensurate host-guest polymorph found above 21 GPa in static compression at room temperature. Shock melting of the host-guest phase is observed between 53 and 72 GPa with the disappearance of Bragg scattering and the growth of a broad asymmetric diffraction peak from the high-density liquid.