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.

Multiorgan MRI findings after hospitalisation with COVID-19 in the UK (C-MORE): a prospective, multicentre, observational cohort study

INTRODUCTION

The multiorgan impact of moderate to severe coronavirus infections in the post-acute phase is still poorly understood. We aimed to evaluate the excess burden of multiorgan abnormalities after hospitalisation with COVID-19, evaluate their determinants, and explore associations with patient-related outcome measures.

METHODS

In a prospective, UK-wide, multicentre MRI follow-up study (C-MORE), adults (aged ≥18 years) discharged from hospital following COVID-19 who were included in Tier 2 of the Post-hospitalisation COVID-19 study (PHOSP-COVID) and contemporary controls with no evidence of previous COVID-19 (SARS-CoV-2 nucleocapsid antibody negative) underwent multiorgan MRI (lungs, heart, brain, liver, and kidneys) with quantitative and qualitative assessment of images and clinical adjudication when relevant. Individuals with end-stage renal failure or contraindications to MRI were excluded. Participants also underwent detailed recording of symptoms, and physiological and biochemical tests. The primary outcome was the excess burden of multiorgan abnormalities (two or more organs) relative to controls, with further adjustments for potential confounders. The C-MORE study is ongoing and is registered with ClinicalTrials.gov, NCT04510025.

FINDINGS

Of 2710 participants in Tier 2 of PHOSP-COVID, 531 were recruited across 13 UK-wide C-MORE sites. After exclusions, 259 C-MORE patients (mean age 57 years [SD 12]; 158 [61%] male and 101 [39%] female) who were discharged from hospital with PCR-confirmed or clinically diagnosed COVID-19 between March 1, 2020, and Nov 1, 2021, and 52 non-COVID-19 controls from the community (mean age 49 years [SD 14]; 30 [58%] male and 22 [42%] female) were included in the analysis. Patients were assessed at a median of 5·0 months (IQR 4·2-6·3) after hospital discharge. Compared with non-COVID-19 controls, patients were older, living with more obesity, and had more comorbidities. Multiorgan abnormalities on MRI were more frequent in patients than in controls (157 [61%] of 259 vs 14 [27%] of 52; p<0·0001) and independently associated with COVID-19 status (odds ratio [OR] 2·9 [95% CI 1·5-5·8]; padjusted=0·0023) after adjusting for relevant confounders. Compared with controls, patients were more likely to have MRI evidence of lung abnormalities (p=0·0001; parenchymal abnormalities), brain abnormalities (p<0·0001; more white matter hyperintensities and regional brain volume reduction), and kidney abnormalities (p=0·014; lower medullary T1 and loss of corticomedullary differentiation), whereas cardiac and liver MRI abnormalities were similar between patients and controls. Patients with multiorgan abnormalities were older (difference in mean age 7 years [95% CI 4-10]; mean age of 59·8 years [SD 11·7] with multiorgan abnormalities vs mean age of 52·8 years [11·9] without multiorgan abnormalities; p<0·0001), more likely to have three or more comorbidities (OR 2·47 [1·32-4·82]; padjusted=0·0059), and more likely to have a more severe acute infection (acute CRP >5mg/L, OR 3·55 [1·23-11·88]; padjusted=0·025) than those without multiorgan abnormalities. Presence of lung MRI abnormalities was associated with a two-fold higher risk of chest tightness, and multiorgan MRI abnormalities were associated with severe and very severe persistent physical and mental health impairment (PHOSP-COVID symptom clusters) after hospitalisation.

INTERPRETATION

After hospitalisation for COVID-19, people are at risk of multiorgan abnormalities in the medium term. Our findings emphasise the need for proactive multidisciplinary care pathways, with the potential for imaging to guide surveillance frequency and therapeutic stratification.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Female UK Army Service personnel are at greater risk of work-related morbidity on return to duty postpartum

INTRODUCTION

The 2016 Interim Report on the Health Risks to Women in Ground Close Combat Roles highlighted an increased risk of skeletal injury and significant physiological changes, including increased ligament laxity and decreased bone mineral content, during the postpartum period. The report called for further research and a re-evaluation of postpartum policy to optimise the return of female Service personnel to arduous employment. The purpose of this study was to determine whether returning to duty is at greater risk of injury and illness in the first year postpartum than they were prepregnancy.

METHODS

Fifty-five female UK Army Service personnel aged 18-41 years, who had given birth in the previous 4 years, completed a lifestyle questionnaire and gave written consent for a review of their medical records. The number of working days lost (WDL) due to illness, injury and combined illness and injury was obtained from medical records, for 1 year prepregnancy and 1 year postpartum. Female Service personnel returned to duty at different time-points postpartum, so data were expressed as WDL/week.

RESULTS

WDL/week due to illness and combined illness and injury were higher postpartum compared with prepregnancy (p<0.05). WDL/week due to combined illness and injury was significantly lower prepregnancy (p<0.05) and at 0-26 weeks postpartum (p<0.05), compared with 26-52 weeks postpartum.

CONCLUSIONS

Postpartum female UK Army Service personnel are at greater risk of illness and a combination of illness and injury in the year after giving birth, compared with prepregnancy. The study suggests female Service personnel are unprepared for the demands of full active duty in the first year postpartum.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study

BACKGROUND

No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge.

METHODS

The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing.

FINDINGS

2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7-9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46-0·99]), obesity (0·50 [0·34-0·74]) and invasive mechanical ventilation (0·42 [0·23-0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74-1·00]), at 5 months (0·74 [0·64-0·88]) to 1 year (0·75 [0·62-0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters.

INTERPRETATION

The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Real world radiation exposure in left atrial appendage occlusion device implantation performed in a high volume center

 

Left atrial appendage occlusion (LAAO) is an established and effective treatment to reduce the risk of thromboembolic stroke derived from the LAA in patient with non valvular atrial fibrillation. Per-cutaneous closure of the LAA is typically guided by fluoroscopic and echocardiographic guidance.

The purpose of our study is to ascertain real world radiation exposure during the LAAO performed in our institution and the interplay of different variables and patient characteristics.

Our study retrospectively analyzed all consecutive LAAO procedures performed at our Tertiary level Teaching Hospital. Data was collected using Hospital electronic records and cardiac catherization laboratory records.

A total of 261 patients who underwent LAAO were identified, 28% were female. Average age at the time of procedure was 77 years (range 54–93 years). Mean fluoroscopy time was 10.2 minutes (±7.0), average Radiation dose was 67 gy/cm2 (±73). Interestingly, gy/cm2 per minute of fluoroscopy averaged at 6.69 (±5.0).

Subgroup analysis focused on the effect of Body mass index (BMI) on radiation dose. Since the recent introduction of a partial electronic health record system, BMI data was only available on 161 patients. The cohort with BMI &lt;30 had a mean radiation dose of 57±62 gy/cm2, whereas for BMI &gt;30 mean dose was 96.8±68, p=0.0025 (95% CI (65 to 14)).

Analysis by the four different device types (Watchman, Watchman Flx, Wavecrest and ACP) were used for LAAO, with highest number been watchman (n=189). Upon comparing the radiation exposure in our study cohort watchman device had the least Dose adjusted Product (DAP) at 62gy/cm2 but the newer watchman flx (n=25) had slightly lower gy/cm2 per minute of fluoroscopy time 6.58±3.41 versus 6.83±5.56.

In addition, operator volume between our two implanters was assessed. Our highest volume operator implanted the majority of devices (n=235) whilst the Watchman Flx was predominantly implanted by our newer implanter (n=26). Despite the relatively modest numbers of the Watchman Flx, there was minimal difference in exposure time in favor of the more senior interventionist.

In conclusion, LAAO in our center has encouraging radiation safety data, which is comparable to previously published data in internationally recognized high volume centers. Normal BMI patients had the least radiation exposure, with the dose increasing with rising BMI.

Funding Acknowledgement

Type of funding sources: None. Bar Graph, radiation dose vs BMIScatter Plot, radiation dose vs BMI

Why do healthcare professionals fail to escalate as per the early warning system (EWS) protocol? A qualitative evidence synthesis of the barriers and facilitators of escalation

Background

Early warning systems (EWSs) are used to assist clinical judgment in the detection of acute deterioration to avoid or reduce adverse events including unanticipated cardiopulmonary arrest, admission to the intensive care unit and death. Sometimes healthcare professionals (HCPs) do not trigger the alarm and escalate for help according to the EWS protocol and it is unclear why this is the case. The aim of this qualitative evidence synthesis was to answer the question ‘why do HCPs fail to escalate care according to EWS protocols?’ The findings will inform the update of the National Clinical Effectiveness Committee (NCEC) National Clinical Guideline No. 1 Irish National Early Warning System (INEWS).

Methods

A systematic search of the published and grey literature was conducted (until February 2018). Data extraction and quality appraisal were conducted by two reviewers independently using standardised data extraction forms and quality appraisal tools. A thematic synthesis was conducted by two reviewers of the qualitative studies included and categorised into the barriers and facilitators of escalation. GRADE CERQual was used to assess the certainty of the evidence.

Results

Eighteen studies incorporating a variety of HCPs across seven countries were included. The barriers and facilitators to the escalation of care according to EWS protocols were developed into five overarching themes: Governance, Rapid Response Team (RRT) Response, Professional Boundaries, Clinical Experience, and EWS parameters. Barriers to escalation included: Lack of Standardisation, Resources, Lack of accountability, RRT behaviours, Fear, Hierarchy, Increased Conflict, Over confidence, Lack of confidence, and Patient variability. Facilitators included: Accountability, Standardisation, Resources, RRT behaviours, Expertise, Additional support, License to escalate, Bridge across boundaries, Clinical confidence, empowerment, Clinical judgment, and a tool for detecting deterioration. These are all individual yet inter-related barriers and facilitators to escalation.

Conclusions

The findings of this qualitative evidence synthesis provide insight into the real world experience of HCPs when using EWSs. This in turn has the potential to inform policy-makers and HCPs as well as hospital management about emergency response system-related issues in practice and the changes needed to address barriers and facilitators and improve patient safety and quality of care.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12873-021-00403-9.

P74 Cervical disc arthroplasty employing a novel compressible prosthesis: a single arm observational study of 101 patients

Objectives

The study aims to evaluate the radiological, clinical efficacy and safety of a novel compressible cervical disc prosthesis in the treatment of degenerative cervical radiculopathy

Design

Observational non-randomised case series based in two centres.

Subjects

101 consecutive patients (137 artificial discs) treated for cervical radiculopathy secondary to cervical disc degeneration. Mean age at operation 45.4 years.

Methods

Neck Disability Index, Visual Analogue Score for neck and arm pain, Euro Quality of Life −5D survey, index level range of movement, heterotopic ossification, adjacent level disease, re-intervention rate and safety profile were assessed. Clinical (outpatient and telephone questionnaires) and radiological (Nuvaline and McKeeson PACS suites) were employed

Results

Index range of movement was 7.9 degrees pre operatively and 7.6 at two years. 2 re operations at supradjacent levels took place post treatment in a 35 month follow-up period. 1 post-operative haematoma and 1 delayed infection occurred. All four primary outcome measures exhibited significant improvement from baseline to last follow up; NDI (47.5 to 24.9, p<0.001) EURO QOL index (0.36 to 0.84, p<0.0001) and VAS Arm (5.6 to 0.85 p<0.0001) and VAS Neck (7.1 to 1.7, p<0.0001).

Conclusions

The compressible disc prosthesis preserved 96.2% of the initial range of movement at index level whilst exhibiting a favourable re operation rate and safety profile.

P82 Pelvic neurophysiological and urodynamics findings in patients with sacral-level tarlov cysts

Objectives

Sacral Tarlov cysts (TC) are frequent incidental findings on spinal MRI. Controversy remains regarding their ability to cause nerve root compression. Pelvic neurophysiological and urodynamics testing provides information about sacral nerve root involvement.

Design

Case series

Subjects

Patients with MRI evidence of sacral (S1, 2 or 3) TC seen in the Uro-neurology Department between 2011 and 2018.

Methods

Clinical, neurophysiological and urodynamics data were reviewed.

Results

13 patients (9 females, mean age54/SD13.1) were included. Symptoms were urgency/incontinence (n=8), hesitancy/urinary retention (n=7), bowel complaints (n=4), sexual complaints (n=3), back pain (n=5), genital/pelvic pain (n=6), genital numbness (n=5), impaired sensation of bladder fullness (n=2), lower limb (LL) pain/hypoesthesia (n=6), LL weakness (n=2). The following neurophysiological abnormalities were seen: anal sphincter EMG (n=10) evidence for reinnervation (n=8), pudendal sensory evoked potentials (SEPs) (n=6) absent response (n=1), S2 and S3 dermatomal SEPs (n=6) absent response (n=2), sympathetic skin response (n=6) absent response (n=3). Findings in cystometry (n=5) were: detrusor underactivity (n=2), detrusor after-contraction (n=1), equivocal obstructed voiding (n=1) and reduced bladder compliance (n=1).

Conclusions

Abnormal results in urodynamics and pelvic neurophysiology suggest involvement of the somatic and autonomic sacral innervation. Further studies are required to explore any association between structural changes on MRI and functional changes in urodynamics and neurophysiology.

Identification of Compounds with pH-Dependent Bactericidal Activity against Mycobacterium tuberculosis

To find new inhibitors of Mycobacterium tuberculosis that have novel mechanisms of action, we miniaturized a high throughput screen to identify compounds that disrupt pH homeostasis. We adapted and validated a 384-well format assay to determine intrabacterial pH using a ratiometric green fluorescent protein. We screened 89000 small molecules under nonreplicating conditions and confirmed 556 hits that reduced intrabacterial pH (below pH 6.5). We selected five compounds that disrupt intrabacterial pH homeostasis and also showed some activity against nonreplicating bacteria in a 4-stress model, but with no (or greatly reduced) activity against replicating bacteria. The compounds selected were two benzamide sulfonamides, a benzothiadiazole, a bissulfone, and a thiadiazole, none of which are known antibacterial agents. All of these five compounds demonstrated bactericidal activity against nonreplicating bacteria in buffer. Four of the five compounds demonstrated increased activity under low pH conditions. None of the five compounds acted as ionophores or as general disrupters of membrane potential. These compounds are useful starting points for work to elucidate their mechanism of action and their utility for drug discovery.

A high-throughput whole cell screen to identify inhibitors of Mycobacterium tuberculosis

Tuberculosis is a disease of global importance for which novel drugs are urgently required. We developed a whole-cell phenotypic screen which can be used to identify inhibitors of Mycobacterium tuberculosis growth. We used recombinant strains of virulent M. tuberculosis which express far-red fluorescent reporters and used fluorescence to monitor growth in vitro. We optimized our high throughput assays using both 96-well and 384-well plates; both formats gave assays which met stringent reproducibility and robustness tests. We screened a compound set of 1105 chemically diverse compounds previously shown to be active against M. tuberculosis and identified primary hits which showed ≥ 90% growth inhibition. We ranked hits and identified three chemical classes of interest-the phenoxyalkylbenzamidazoles, the benzothiophene 1-1 dioxides, and the piperidinamines. These new compound classes may serve as starting points for the development of new series of inhibitors that prevent the growth of M. tuberculosis. This assay can be used for further screening, or could easily be adapted to other strains of M. tuberculosis.

A Breast Screening Shawl to Help Aboriginal Women Feel More Comfortable and Culturally Safe

Background: It is recommended that Australian women aged 50-74 have a breast screen every two years. Aboriginal women have lower breast screening participation than the general population, and face barriers at a system, service and individual level including: • Cultural: lack of cultural awareness/safety at screening services • Fear: historical apprehension about health services due to the after effects of colonization and intergenerational trauma • Shame: feeling embarrassment/shame at being undressed in front of a stranger • Past experience: having a past unpleasant breast screen, or hearing about someone else' • Knowledge: lack of knowledge about screening • Logistics: not knowing service provider locations or limited access to transport During a 2016 project between BreastScreen Victoria (BSV) and Women's Health West, Aboriginal women discussed the need for a shawl to cover them during screening. This idea is based on a successful New Zealand model. Based on this, the Victorian Aboriginal Health Service (VAHS), Victorian Aboriginal Community Controlled Health Organization (VACCHO) and BSV formed a partnership to trial a breast screening shawl with Aboriginal women. A key principle underpinning the project is that success will reflect the degree to which this is an Aboriginal-led initiative, driven by the needs of Aboriginal women, and steered by community-based Aboriginal health organizations. Project aims: • Assess whether a cultural, strength based screening process increases engagement of Aboriginal women • Determine whether a screening shawl enhances comfort and culturally safety • Encourage breast screening services to develop culturally safe screening practices • Develop a flexible model that can be easily adapted by other Aboriginal health services to reproduce the shawl, in recognition of the diversity of Aboriginal communities Methods: This project adopted the following strategies: • A project steering group was established • The shawl will be trialled via a group booking at one BSV clinic • Before the group booking, BSV clinic staff will attend culturally safety training • On the trial day, women will attend an information session at VAHS about breast screening and receive their shawl, travel to the BSV clinic together for screening, and return to VAHS to discuss their experiences Results: The trial will be fully evaluated in 2018 to determine whether project aims were achieved. Conclusion: Key learnings to date are: • Breast screening interventions for Aboriginal women must be community-led to ensure they are culturally appropriate, safe and acceptable • Aboriginal women face a number of barriers to breast screening at a system, service and individual level • Health services play a critical role in adopting culturally safe screening practices • Developing a flexible model that can be easily adapted by other Aboriginal health services is critical in ensuring the sustainability and acceptability of the shawl.

Fabrication of microfluidic cavities using Si-to-glass anodic bonding

We demonstrate the fabrication of ∼1.08 μm deep microfluidic cavities with characteristic size as large as 7 mm × 11 mm or 11 mm diameter, using a silicon-glass anodic bonding technique that does not require posts to act as separators to define cavity height. Since the phase diagram of ³He is significantly altered under confinement, posts might act as pinning centers for phase boundaries. The previous generation of cavities relied on full wafer-bonding which is more prone to failure and requires dicing post-bonding, whereas these cavities are made by bonding a pre-cut piece of Hoya SD-2 glass to a patterned piece of silicon in which the cavity is defined by etching. Anodic bonding was carried out at 425 °C with 200 V, and we observe that pressurizing the cavity to failure (>30 bars pressure) results in glass breaking, rather than the glass-silicon bond separation. In this article, we discuss the detailed fabrication of the cavity, its edges, and details of the junction between the coin silver fill line and the silicon base of the cavity that enables a low internal-friction joint. This feature is important for mass coupling torsional oscillator experimental assays of the superfluid inertial contribution where a high quality factor (Q) improves frequency resolution. The surface preparation that yields well-characterized smooth surfaces to eliminate pinning sites, the use of transparent glass as a cover permitting optical access, low temperature capability, and attachment of pressure-capable ports for fluid access may be features that are important in other applications.

Comparative studies of cellular viability levels on 2D and 3D in vitro culture matrices

In this study, the cellular viability and function of immortalized human cervical and dermal cells are monitored and compared in conventional 2D and two commercial 3D membranes, Collagen and Geltrex, of varying working concentration and volume. Viability was monitored with the aid of the Alamar Blue assay, cellular morphology was monitored with confocal microscopy, and cell cycle studies and cell death mechanism studies were performed with flow cytometry. The viability studies showed apparent differences between the 2D and 3D culture systems, the differences attributed in part to the physical transition from 2D to 3D environment causing alterations to effective resazurin concentration, uptake and conversion rates, which was dependent on exposure time, but also due to the effect of the membrane itself on cellular function. These effects were verified by flow cytometry, in which no significant differences in viable cell numbers between 2D and 3D systems were observed after 24 h culture. The results showed the observed effect was different after shorter exposure periods, was also dependent on working concentration of the 3D system and could be mediated by altering the culture vessel size. Cell cycle analysis revealed cellular function could be altered by growth on the 3D substrates and the alterations were noted to be dependent on 3D membrane concentration. The use of 3D culture matrices has been widely interpreted to result in "improved viability levels" or "reduced" toxicity or cellular "resistance" compared to cells cultured on traditional 2D systems. The results of this study show that cellular health and viability levels are not altered by culture in 3D environments, but their normal cycle can be altered as indicated in the cell cycle studies performed and such variations must be accounted for in studies employing 3D membranes for in vitro cellular screening.

A Target-Based Whole Cell Screen Approach To Identify Potential Inhibitors of Mycobacterium tuberculosis Signal Peptidase

The general secretion (Sec) pathway is a conserved essential pathway in bacteria and is the primary route of protein export across the cytoplasmic membrane. During protein export, the signal peptidase LepB catalyzes the cleavage of the signal peptide and subsequent release of mature proteins into the extracellular space. We developed a target-based whole cell assay to screen for potential inhibitors of LepB, the sole signal peptidase in Mycobacterium tuberculosis, using a strain engineered to underexpress LepB (LepB-UE). We screened 72,000 compounds against both the Lep-UE and wild-type (wt) strains. We identified the phenylhydrazone (PHY) series as having higher activity against the LepB-UE strain. We conducted a limited structure-activity relationship determination around a representative PHY compound with differential activity (MICs of 3.0 μM against the LepB-UE strain and 18 μM against the wt); several analogues were less potent against the LepB overexpressing strain. A number of chemical modifications around the hydrazone moiety resulted in improved potency. Inhibition of LepB activity was observed for a number of compounds in a biochemical assay using cell membrane fraction derived from M. tuberculosis. Compounds did not increase cell permeability, dissipate membrane potential, or inhibit an unrelated mycobacterial enzyme, suggesting a specific mode of action related to the LepB secretory mechanism.

The ‘three-legged stool’

Many hospitals do not have a structured process of consent, the attainment of which can often be rather ‘last-minute’ and somewhat chaotic. This is a surprising state of affairs as spinal surgery is a high-risk surgical specialty with potential for expensive litigation claims. More recently, the Montgomery ruling by the United Kingdom Supreme Court has placed the subject of informed consent into the spotlight.

There is a paucity of practical guidance on how a consent process can be achieved in a busy clinical setting. The British Association of Spinal Surgeons (BASS) has convened a working party to address this need. To our knowledge this is the first example of a national professional body, representing a single surgical specialty, taking such a fundamental initiative.

In a hard-pressed clinical environment, the ability to achieve admission reliably on the day of surgery, in patients at ease with their situation and with little likelihood of late cancellation, will be of great benefit. It will reduce litigation and improve the patient experience.

Cite this article: Bone Joint J 2016;98-B:1427–30.

Using informatics to help implement clinical guidelines

Clinical guidelines are a positive contribution to improving the quality of care and assuring its effectiveness. However, clinical guidelines need to be integrated with other quality improvement initiatives to fulfil their potential. We propose a model of how informatics can support the implementation of clinical guidelines and their integration into systems for decision support and clinical audit. Each element of the model is discussed in turn and particular attention is paid to how informatics can also facilitate the involvement of patients in developing and using clinical guidelines. The word ‘patients’ is used to describe all users of health services.

Primary current-sensing noise thermometry in the millikelvin regime

The use of low-temperature platforms with base temperatures below 1 K is rapidly expanding, for fundamental science, sensitive instrumentation and new technologies of potentially significant commercial impact. Precise measurement of the thermodynamic temperature of these low-temperature platforms is crucial for their operation. In this paper, we describe a practical and user-friendly primary current-sensing noise thermometer (CSNT) for reliable and traceable thermometry and the dissemination of the new kelvin in this temperature regime. Design considerations of the thermometer are discussed, including the optimization of a thermometer for the temperature range to be measured, noise sources and thermalization. We show the procedure taken to make the thermometer primary and contributions to the uncertainty budget. With standard laboratory instrumentation, a relative uncertainty of 1.53% is obtainable. Initial comparison measurements between a primary CSNT and a superconducting reference device traceable to the PLTS-2000 (Provisional Low Temperature Scale of 2000) are presented between 66 and 208 mK, showing good agreement within the k=1 calculated uncertainty.

Silver nanoparticles induce pro-inflammatory gene expression and inflammasome activation in human monocytes

A complete cytotoxic profile of exposure to silver (AgNP) nanoparticles investigating their biological effects on the innate immune response of circulating white blood cells is required to form a complete understanding of the risk posed. This was explored by measuring AgNP-stimulated gene expression of the pro-inflammatory cytokines interleukin-1 (IL-1), interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-α) in THP-1 monocytes. A further study, on human monocytes extracted from a cohort of blood samples, was carried out to compare with the AgNP immune response in THP-1 cells along with the detection of pro-IL-1β which is a key mediator of the inflammasome complex. The aims of the study were to clearly demonstrate that AgNP can significantly up-regulate pro-inflammatory cytokine gene expression of IL-1, IL-6 and TNF-α in both THP-1 cells and primary blood monocytes thus indicating a rapid response to AgNP in circulation. Furthermore, a role for the inflammasome in AgNP response was indicated by pro-IL-1β cleavage and release. These results highlight the potential inflammatory effects of AgNP exposure and the responses evoked should be considered with respect to the potential harm that exposure may cause. Copyright © 2016 John Wiley & Sons, Ltd.

Raman micro spectroscopy for in vitro drug screening: subcellular localisation and interactions of doxorubicin

Raman spectroscopy is used for the localization and tracking of chemotherapeutic drug, doxorubicin, in the intracellular environment of lung cancer cell line. Results show the potential of the technique to monitor the mechanisms of action and response on a molecular level, with subcellular resolution.

Cellular discrimination using in vitro Raman micro spectroscopy: the role of the nucleolus

Raman micro spectroscopy is employed to discriminate between cell lines. Results show the importance of the nuclear sub-cellular organelle, the nucleoli, to differentiate between cancer cell lines with high specificity and sensitivity.

How to interpret computed tomography of the lumbar spine

Computed tomography (CT) of the spine has remained an important tool in the investigation of spinal pathology. This article helps to explain the basics of CT of the lumbar spine to allow the clinician better use of this diagnostic tool.

NMR signature of one-dimensional behavior of 3He in nanopores

We have performed thermodynamic and NMR relaxation time measurements of 3He adsorbed in the pores of the mesoporous molecular sieve MCM-41 at temperatures down to 1.7 K and at a range of frequencies up to 240 kHz. The MCM-41 substrate comprises a uniform array of quasi-1D straight pores with a diameter of 2.3 nm. We preplated the pores with a monolayer of 4He to achieve an effective diameter of 1.6 nm at low temperatures. We made NMR measurements as a function of line density and frequency to investigate the spin dynamics and the effect of dimensionality. We observed T(1) is proportional to ω1/2, which is characteristic of one-dimensional diffusion. At these temperatures this arises from a classical size effect in the narrow pores. Our results demonstrate the possibility to study the spin dynamics of a 1D Tomonaga-Luttinger liquid at lower temperatures, where the 3He liquid will constitute a quantum 1D system.

A high-throughput screen against pantothenate synthetase (PanC) identifies 3-biphenyl-4-cyanopyrrole-2-carboxylic acids as a new class of inhibitor with activity against Mycobacterium tuberculosis

The enzyme pantothenate synthetase, PanC, is an attractive drug target in Mycobacterium tuberculosis. It is essential for the in vitro growth of M. tuberculosis and for survival of the bacteria in the mouse model of infection. PanC is absent from mammals. We developed an enzyme-based assay to identify inhibitors of PanC, optimized it for high-throughput screening, and tested a large and diverse library of compounds for activity. Two compounds belonging to the same chemical class of 3-biphenyl-4- cyanopyrrole-2-carboxylic acids had activity against the purified recombinant protein, and also inhibited growth of live M. tuberculosis in manner consistent with PanC inhibition. Thus we have identified a new class of PanC inhibitors with whole cell activity that can be further developed.

Two-dimensional ferromagnetism of a 3He film: influence of weak frustration

(3)He films adsorbed on the atomically flat surface of graphite provide a model system for the study of two-dimensional magnetism on a triangular lattice. We have made a study of the regime in which the T=0 ground state of the second (3)He layer is a fully polarized ferromagnet. NMR, using broadband SQUID detection, at a range of low fields above the spin-flop transition, and over a wide temperature range 0.3-200 mK, has enabled us to disentangle the influence of sample finite size effects and magnetic field on the spin-wave spectrum. We demonstrate that the spin-wave spectrum is governed by a different effective exchange constant than that determining the high temperature magnetism. This is understood in terms of frustrated atomic ring exchange.

A dual read-out assay to evaluate the potency of compounds active against Mycobacterium tuberculosis

Tuberculosis is a serious global health problem caused by the bacterium Mycobacterium tuberculosis. There is an urgent need for discovery and development of new treatments, but this can only be accomplished through rapid and reproducible M. tuberculosis assays designed to identify potent inhibitors. We developed an automated 96-well assay utilizing a recombinant strain of M. tuberculosis expressing a far-red fluorescent reporter to determine the activity of novel compounds; this allowed us to measure growth by monitoring both optical density and fluorescence. We determined that optical density and fluorescence were correlated with cell number during logarithmic phase growth. Fluorescence was stably maintained without antibiotic selection over 5 days, during which time cells remained actively growing. We optimized parameters for the assay, with the final format being 5 days' growth in 96-well plates in the presence of 2% w/v DMSO. We confirmed reproducibility using rifampicin and other antibiotics. The dual detection method allows for a reproducible calculation of the minimum inhibitory concentration (MIC), at the same time detecting artefacts such as fluorescence quenching or compound precipitation. We used our assay to confirm anti-tubercular activity and establish the structure activity relationship (SAR) around the imidazo[1,2-a]pyridine-3-carboxamides, a promising series of M. tuberculosis inhibitors.

Quantum transport in mesoscopic 3He films: experimental study of the interference of bulk and boundary scattering

We discuss the mass transport of a degenerate Fermi liquid ^{3}He film over a rough surface, and the film momentum relaxation time, in the framework of theoretical predictions. In the mesoscopic regime, the anomalous temperature dependence of the relaxation time is explained in terms of the interference between elastic boundary scattering and inelastic quasiparticle-quasiparticle scattering within the film. We exploit a quasiclassical treatment of quantum size effects in the film in which the surface roughness, whose power spectrum is experimentally determined, is mapped into an effective disorder potential within a film of uniform thickness. Confirmation is provided by the introduction of elastic scattering centers within the film. The improved understanding of surface roughness scattering may impact on enhancing the conductivity in thin metallic films.

Serum procalcitonin, interleukin-6, soluble intercellular adhesin molecule-1 and IgG to short-chain exocellular lipoteichoic acid as predictors of infection in total joint prosthesis revision

The diagnosis of prosthetic joint infection and its differentiation from aseptic loosening remains problematic. The definitive laboratory diagnostic test is the recovery of identical infectious agents from multiple intraoperative tissue samples; however, interpretation of positive cultures is often complex as infection is frequently associated with low numbers of commensal microorganisms, in particular the coagulase-negative staphylococci (CNS). In this investigation, the value of serum procalcitonin (PCT), interleukin-6 (IL-6) and soluble intercellular adhesion molecule-1 (sICAM-1) as predictors of infection in revision hip replacement surgery is assessed. Furthermore, the diagnostic value of serum IgG to short-chain exocellular lipoteichoic acid (sce-LTA) is assessed in patients with infection due to CNS. Presurgical levels of conventional serum markers of infection including C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and white blood cell count (WBC) is also established. Forty-six patients undergoing revision hip surgery were recruited with a presumptive clinical diagnosis of either septic (16 patients) or aseptic loosening (30 patients). The diagnosis was confirmed microbiologically and levels of serum markers were determined. Serum levels of IL-6 and sICAM-1 were significantly raised in patients with septic loosening (P = 0.001 and P = 0.0002, respectively). Serum IgG to sce-LTA was elevated in three out of four patients with infection due to CNS. In contrast, PCT was not found to be of value in differentiating septic and aseptic loosening. Furthermore, CRP, ESR and WBC were significantly higher (P = 0.0001, P = 0.0001 and P = 0.003, respectively) in patients with septic loosening. Serum levels of IL-6, sICAM-1 and IgG to sce-LTA may provide additional information to facilitate the diagnosis of prosthetic joint infection.

Superficial thrombophlebitis in varicose vein disease: the particular role of methylenetetrahydrofolate reductase

BACKGROUND

The purpose of this study was to compare the genetic background of superficial (SVT) and deep vein thrombosis (DVT).

METHODS

Factor V (FV)-Leiden (G16891A)-, factor II(G20210A)-mutations, protein C- and S, as well as methylenetetrahydrofolate reductase (MTHFR) polymorphisms at C677T and A1298C, and serum homocysteine levels (hcy) were determined in 29 patients with SVT and 26 with DVT. Findings FV- and -II-mutations were less frequent in patients with SVT (2/3) compared with DVT (9/5), respectively (P < 0.002 in case of FV). However, the frequency of the MTHFR C677T polymorphism was significantly higher in patients with SVT compared with DVT (CT 12 versus 10, and TT 7 versus 1, respectively, P << 0.001). The distribution of the MTHFR A1298C genotype and serum hcy levels was similar in both patient groups. Protein S-deficiency was recorded once (SVT). Interpretation These results suggest that the MTHFR C677T-mutant genetically predisposes its carriers to SVT which may contribute to hypercoagulation in pre-existing varicose vein disease.

105. MEIOTIC ACROBATS: MONOTREME SEX CHROMOSOME ORGANISATION DURING SPERMATOGENESIS

Monotremes feature an extraordinarily complex sex chromosome system which shares extensive homology with bird sex chromosomes but no homology to sex chromosomes of other mammals (1,2,3). At meiotic prophase I the ten sex chromosomes in platypus (nine in echidna) assemble in a sex chromosome chain. We previously identified the multiple sex chromosomes in platypus and echidna that form the meiotic chain in males (1,2,4). We showed that sex chromosomes assembly in the chain in a specific order (5) and that they segregate alternately (1). In secondary spermatocytes we observed clustering of X and Y chromosomes in sperm (6). Our current research investigates the formation of the synaptonemal complex, recombination and meiotic silencing of monotreme sex chromosomes. Meiotic sex chromosome inactivation (MSCI) has been observed in eutherian mammals, marsupials and birds but has so far not been investigated experimentally in monotremes. We found that during pachytene the X5Y5 end of the chain closely associates with the nucleolus and accumulates repressive chromatin marks (e.g. histone variant mH2A). In contrast to the differential accumulation of mH2A we observe extensive loading of the cohesin SMC3 on sex chromosomes in particular during the pachytene stage of meiotic prophase I. We have also used markers of active transcription and gene expression analysis to investigate gene activity in platypus meiotic cells. I will discuss how these findings contribute to our current understanding of the meiotic organisation of monotreme sex chromosomes and the evolution of MSCI in birds and mammals. (1) Grützner et al. (2004), Nature 432: 913–917.(2) Rens et al. (2007), Genome Biology 16;8(11): R243.(3) Veyrunes et al. (2008), Genome Research, 18(6): 995–1004.(4) Rens et al. (2004), Proceedings of the National Academy of Sciences USA. 101 (46): 16 257–16 261.(5) Daish et al. (2009), Reprod Fertil Dev. 21(8): 976–84.(6) Tsend-Ayush et al. (2009), Chromosoma 118(1): 53–69.

Anodically bonded submicron microfluidic chambers

We demonstrate the use of anodic bonding to fabricate cells with characteristic size as large as 7 x 10 mm(2), with height of approximately 640 nm, and without any internal support structure. The cells were fabricated from Hoya SD-2 glass and silicon wafers, each with 3 mm thickness to maintain dimensional stability under internal pressure. Bonding was carried out at 350 degrees C and 450 V with an electrode structure that excluded the electric field from the open region. We detail fabrication and characterization steps and also discuss the design of the fill line for access to the cavity.

Retropharyngeal pseudomeningocele

A 38-year-old male was found to have a retropharyngeal pseudomeningocele along with C1 - C2 dislocation. Absence of any possible history, misleading circumstantial evidence and rarity of the entity made it impossible to diagnose the condition preoperatively. Concurrent medical problems dominated and the patient died. As a result, outcome of the pseudomeningocele could not be evaluated.

Single walled carbon nanotubes induce indirect cytotoxicity by medium depletion in A549 lung cells

The ability of two types of single walled carbon nanotubes (SWCNT), namely Arc Discharge (AD) and HiPco single walled carbon nanotubes, to induce an indirect cytotoxicity in A549 lung cells by means of medium depletion was investigated. The nanotubes were dispersed in a commercial cell culture medium and subsequently removed by centrifugation and filtration. Spectroscopic analysis confirmed the removal of the nanotubes and showed differing degrees of alteration of the composition of the medium upon the removal of the nanotubes. The ability to induce an indirect cytotoxic effect by altering the medium was evaluated using two endpoints, namely the Alamar Blue (AB) and the Clonogenic assay. Exposure of the A549 cells to the depleted medium which had previously contained carbonaceous nanoparticles, revealed significant cytotoxicity for both endpoints employed. The results presented demonstrate that single walled carbon nanotubes can induce an indirect cytotoxicity by alteration of cell culture medium (in which they have previously been dispersed) which potentially results in a false positive toxic effect being observed in cytotoxicity studies.