Improving sensitivity through data augmentation with synthetic lymph node metastases for AI-based analysis of PSMA PET-CT images

BACKGROUND

We developed a fully automated artificial intelligence (AI)AI-based-based method for detecting suspected lymph node metastases in prostate-specific membrane antigen (PSMA)(PSMA) positron emission tomography-computed tomography (PET-CT)(PET-CT) images of prostate cancer patients by using data augmentation that adds synthetic lymph node metastases to the images to expand the training set.

METHODS

Synthetic data were derived from original training images to which new synthetic lymph node metastases were added. Thus, the original training set from a previous study (n = 420) was expanded by one synthetic image for every original image (n = 840), which was used to train an AI model. The performance of the AI model was compared to that of nuclear medicine physicians and a previously developed AI model. The human readers were alternately used as a reference and compared to either another reading or AI model.

RESULTS

The new AI model had an average sensitivity of 84% for detecting lymph node metastases compared with 78% for human readings. Our previously developed AI method without synthetic data had an average sensitivity of 79%. The number of false positive lesions were slightly higher for the new AI model (average 3.3 instances per patient) compared to human readings and the previous AI model (average 2.8 instances per patient), while the number of false negative lesions was lower.

CONCLUSIONS

Creating synthetic lymph node metastases, as a form of data augmentation, on [18F]PSMA-1007F]PSMA-1007 PETPET-CT-CT images improved the sensitivity of an AI model for detecting suspected lymph node metastases. However, the number of false positive lesions increased somewhat.

Effects of adding early cooperation and a work-place dialogue meeting to primary care management for sick-listed patients with stress-related disorders: CO-WORK-CARE-Stress - a pragmatic cluster randomised controlled trial

OBJECTIVES

To investigate whether intensified cooperation between general practitioner (GP), care manager and rehabilitation coordinator (RC) for patients sick-listed for stress-related mental disorder, combined with a person-centred dialogue meeting with employer, could reduce sick-leave days compared with usual care manager contact.

DESIGN

Pragmatic cluster-randomised controlled trial, randomisation at primary care centre (PCC) level.

SETTING

PCCs in Region Västra Götaland, Sweden, with care manager organisation.

PARTICIPANTS

Of 30 invited PCCs, 28 (93%) accepted the invitation and recruited 258 patients newly sick-listed due to stress-related mental disorder (n = 142 intervention, n = 116 control PCCs).

INTERVENTION

Cooperation between GP, care manager and rehabilitation coordinator from start of illness notification plus a person-centred dialogue meeting between patient and employer within 3 months. Regular contact with care manager was continued at the control PCCs.

MAIN OUTCOME MEASURES

12-months net and gross number of sick-leave days. Secondary outcomes: Symptoms of stress, depression, anxiety; work ability and health related quality of life (EQ-5D) over 12 months.

RESULTS

There were no significant differences between intervention and control groups after 12 months: days on sick-leave (12-months net sick-leave days, intervention, mean = 110.7 days (95% confidence interval (CI) 82.6 - 138.8); control, mean = 99.1 days (95% CI 73.9 - 124.3)), stress, depression, or anxiety symptoms, work ability or EQ-5D. There were no significant differences between intervention and control groups concerning proportion on sick-leave after 3, 6, 12 months. At 3 months 64.8% were on sick-leave in intervention group vs 54.3% in control group; 6 months 38% vs 32.8%, and12 months 16.9% vs 15.5%.

CONCLUSION

Increased cooperation at the PCC between GP, care manager and RC for stress-related mental disorder coupled with an early workplace contact in the form of a person-centred dialogue meeting does not reduce days of sick-leave or speed up rehabilitation.Trial registration: ClinicalTrials.gov Identifier: NCT03250026 https://clinicaltrials.gov/study/NCT03250026?tab=results#publicationsCO-WORK-CAREFirst Posted: August 15, 2017. Recruitment of PCCs: September 2017. Inclusion of patients from December 2017.

Brain tumor segmentation using synthetic MR images - A comparison of GANs and diffusion models

Large annotated datasets are required for training deep learning models, but in medical imaging data sharing is often complicated due to ethics, anonymization and data protection legislation. Generative AI models, such as generative adversarial networks (GANs) and diffusion models, can today produce very realistic synthetic images, and can potentially facilitate data sharing. However, in order to share synthetic medical images it must first be demonstrated that they can be used for training different networks with acceptable performance. Here, we therefore comprehensively evaluate four GANs (progressive GAN, StyleGAN 1-3) and a diffusion model for the task of brain tumor segmentation (using two segmentation networks, U-Net and a Swin transformer). Our results show that segmentation networks trained on synthetic images reach Dice scores that are 80%-90% of Dice scores when training with real images, but that memorization of the training images can be a problem for diffusion models if the original dataset is too small. Our conclusion is that sharing synthetic medical images is a viable option to sharing real images, but that further work is required. The trained generative models and the generated synthetic images are shared on AIDA data hub.

Manual prostate MRI segmentation by readers with different experience: a study of the learning progress

OBJECTIVE

To evaluate the learning progress of less experienced readers in prostate MRI segmentation.

MATERIALS AND METHODS

One hundred bi-parametric prostate MRI scans were retrospectively selected from the Göteborg Prostate Cancer Screening 2 Trial (single center). Nine readers with varying degrees of segmentation experience were involved: one expert radiologist, two experienced radiology residents, two inexperienced radiology residents, and four novices. The task was to segment the whole prostate gland. The expert's segmentations were used as reference. For all other readers except three novices, the 100 MRI scans were divided into five rounds (cases 1-10, 11-25, 26-50, 51-76, 76-100). Three novices segmented only 50 cases (three rounds). After each round, a one-on-one feedback session between the expert and the reader was held, with feedback on systematic errors and potential improvements for the next round. Dice similarity coefficient (DSC) > 0.8 was considered accurate.

RESULTS

Using DSC > 0.8 as the threshold, the novices had a total of 194 accurate segmentations out of 250 (77.6%). The residents had a total of 397/400 (99.2%) accurate segmentations. In round 1, the novices had 19/40 (47.5%) accurate segmentations, in round 2 41/60 (68.3%), and in round 3 84/100 (84.0%) indicating learning progress.

CONCLUSIONS

Radiology residents, regardless of prior experience, showed high segmentation accuracy. Novices showed larger interindividual variation and lower segmentation accuracy than radiology residents. To prepare datasets for artificial intelligence (AI) development, employing radiology residents seems safe and provides a good balance between cost-effectiveness and segmentation accuracy. Employing novices should only be considered on an individual basis.

CLINICAL RELEVANCE STATEMENT

Employing radiology residents for prostate MRI segmentation seems safe and can potentially reduce the workload of expert radiologists. Employing novices should only be considered on an individual basis.

KEY POINTS

• Using less experienced readers for prostate MRI segmentation is cost-effective but may reduce quality. • Radiology residents provided high accuracy segmentations while novices showed large inter-reader variability. • To prepare datasets for AI development, employing radiology residents seems safe and might provide a good balance between cost-effectiveness and segmentation accuracy while novices should only be employed on an individual basis.

Automated quantification of PET/CT skeletal tumor burden in prostate cancer using artificial intelligence: The PET index

PURPOSE

Consistent assessment of bone metastases is crucial for patient management and clinical trials in prostate cancer (PCa). We aimed to develop a fully automated convolutional neural network (CNN)-based model for calculating PET/CT skeletal tumor burden in patients with PCa.

METHODS

A total of 168 patients from three centers were divided into training, validation, and test groups. Manual annotations of skeletal lesions in [¹⁸F]fluoride PET/CT scans were used to train a CNN. The AI model was evaluated in 26 patients and compared to segmentations by physicians and to a SUV 15 threshold. PET index representing the percentage of skeletal volume taken up by lesions was estimated.

RESULTS

There was no case in which all readers agreed on prevalence of lesions that the AI model failed to detect. PET index by the AI model correlated moderately strong to physician PET index (mean r = 0.69). Threshold PET index correlated fairly with physician PET index (mean r = 0.49). The sensitivity for lesion detection was 65-76% for AI, 68-91% for physicians, and 44-51% for threshold depending on which physician was considered reference.

CONCLUSION

It was possible to develop an AI-based model for automated assessment of PET/CT skeletal tumor burden. The model's performance was superior to using a threshold and provides fully automated calculation of whole-body skeletal tumor burden. It could be further developed to apply to different radiotracers. Objective scan evaluation is a first step toward developing a PET/CT imaging biomarker for PCa skeletal metastases.

Common carotid segmentation in 18 F-sodium fluoride PET/CT scans: Head-to-head comparison of artificial intelligence-based and manual method

BACKGROUND

Carotid atherosclerosis is a major cause of stroke, traditionally diagnosed late. Positron emission tomography/computed tomography (PET/CT) with ¹⁸ F-sodium fluoride (NaF) detects arterial wall micro-calcification long before macro-calcification becomes detectable by ultrasound, CT or magnetic resonance imaging. However, manual PET/CT processing is time-consuming and requires experience. We compared a convolutional neural network (CNN) approach with manual segmentation of the common carotids.

METHODS

Segmentation in NaF-PET/CT scans of 29 healthy volunteers and 20 angina pectoris patients were compared for segmented volume (Vol) and mean, maximal, and total standardized uptake values (SUVmean, SUVmax, and SUVtotal). SUVmean was the average of SUVmeans within the VOI, SUVmax the highest SUV in all voxels in the VOI, and SUVtotal the SUVmean multiplied by the Vol of the VOI. Intra and Interobserver variability with manual segmentation was examined in 25 randomly selected scans.

RESULTS

Bias for Vol, SUVmean, SUVmax, and SUVtotal were 1.33 ± 2.06, -0.01 ± 0.05, 0.09 ± 0.48, and 1.18 ± 1.99 in the left and 1.89 ± 1.5, -0.07 ± 0.12, 0.05 ± 0.47, and 1.61 ± 1.47, respectively, in the right common carotid artery. Manual segmentation lasted typically 20 min versus 1 min with the CNN-based approach. Mean Vol deviation at repeat manual segmentation was 14% and 27% in left and right common carotids.

CONCLUSIONS

CNN-based segmentation was much faster and provided SUVmean values virtually identical to manually obtained ones, suggesting CNN-based analysis as a promising substitute of slow and cumbersome manual processing.

Women's decision-making related to induced abortion - a cross sectional study during a period of Covid-19 pandemic, in Sweden

OBJECTIVES

To investigate women's decision-making on induced abortion.

MATERIALS AND METHODS

A multi-centre cross-sectional survey among 623 abortion-seeking women in Sweden (2021). The perceived difficulty to decide on abortion was measured using a 7-point Likert scale, and analysed with univariate and multivariate analysis (odds ratios [OR], 95% confidence intervals [CI]).

RESULTS

About half (n = 322;52%) scored 1-4, suggesting the decision was perceived as easier compared to those (n = 292;48%) who scored 5-7. Reasons for the abortion were: poor economy (n = 166;27%), too early in the relationship (n = 154;25.1%), want to work first (n = 147;23.9%), want to study first (n = 132;21.5%), uncertain about the relationship (104;16.9%), and too young (n = 104;16.9%). Predictors for perceiving the decision as difficult: partner's hesitance (OR = 3.18, CI:1.76-5.73), being born outside the Nordic countries (OR = 2.23, CI:1.28-3.87), having discussed the decision with someone (OR = 2.42, CI:1.67-3.50), age ≥30 (OR = 2.22, CI:1.03-4.76), the Covid-19 pandemic (OR = 2.08, CI:1.20-3.59), and the desire to have children in the future (OR = 1.96, CI:1.18-3.28). After confirmed pregnancy, poor mental well-being was more common among those who scored 5-7 (n = 140;47.9%) compared to those who scored 1-4 (n = 122;37.9), p = .029.

CONCLUSION

Women's decision-making on abortion is complex; in times of crises, the decision procedure may be even more difficult. This valuable knowledge could be used to improve and promote satisfactory counselling beyond medical routines.

Safety and efficacy of tenecteplase in patients with wake-up stroke assessed by non-contrast CT (TWIST): a multicentre, open-label, randomised controlled trial

BACKGROUND

Current evidence supports the use of intravenous thrombolysis with alteplase in patients with wake-up stroke selected with MRI or perfusion imaging and is recommended in clinical guidelines. However, access to advanced imaging techniques is often scarce. We aimed to determine whether thrombolytic treatment with intravenous tenecteplase given within 4·5 h of awakening improves functional outcome in patients with ischaemic wake-up stroke selected using non-contrast CT.

METHODS

TWIST was an investigator-initiated, multicentre, open-label, randomised controlled trial with blinded endpoint assessment, conducted at 77 hospitals in ten countries. We included patients aged 18 years or older with acute ischaemic stroke symptoms upon awakening, limb weakness, a National Institutes of Health Stroke Scale (NIHSS) score of 3 or higher or aphasia, a non-contrast CT examination of the head, and the ability to receive tenecteplase within 4·5 h of awakening. Patients were randomly assigned (1:1) to either a single intravenous bolus of tenecteplase 0·25 mg per kg of bodyweight (maximum 25 mg) or control (no thrombolysis) using a central, web-based, computer-generated randomisation schedule. Trained research personnel, who conducted telephone interviews at 90 days (follow-up), were masked to treatment allocation. Clinical assessments were performed on day 1 (at baseline) and day 7 of hospital admission (or at discharge, whichever occurred first). The primary outcome was functional outcome assessed by the modified Rankin Scale (mRS) at 90 days and analysed using ordinal logistic regression in the intention-to-treat population. This trial is registered with EudraCT (2014-000096-80), ClinicalTrials.gov (NCT03181360), and ISRCTN (10601890).

FINDINGS

From June 12, 2017, to Sept 30, 2021, 578 of the required 600 patients were enrolled (288 randomly assigned to the tenecteplase group and 290 to the control group [intention-to-treat population]). The median age of participants was 73·7 years (IQR 65·9-81·1). 332 (57%) of 578 participants were male and 246 (43%) were female. Treatment with tenecteplase was not associated with better functional outcome, according to mRS score at 90 days (adjusted OR 1·18, 95% CI 0·88-1·58; p=0·27). Mortality at 90 days did not significantly differ between treatment groups (28 [10%] patients in the tenecteplase group and 23 [8%] in the control group; adjusted HR 1·29, 95% CI 0·74-2·26; p=0·37). Symptomatic intracranial haemorrhage occurred in six (2%) patients in the tenecteplase group versus three (1%) in the control group (adjusted OR 2·17, 95% CI 0·53-8·87; p=0·28), whereas any intracranial haemorrhage occurred in 33 (11%) versus 30 (10%) patients (adjusted OR 1·14, 0·67-1·94; p=0·64).

INTERPRETATION

In patients with wake-up stroke selected with non-contrast CT, treatment with tenecteplase was not associated with better functional outcome at 90 days. The number of symptomatic haemorrhages and any intracranial haemorrhages in both treatment groups was similar to findings from previous trials of wake-up stroke patients selected using advanced imaging. Current evidence does not support treatment with tenecteplase in patients selected with non-contrast CT.

FUNDING

Norwegian Clinical Research Therapy in the Specialist Health Services Programme, the Swiss Heart Foundation, the British Heart Foundation, and the Norwegian National Association for Public Health.

"Global" cardiac atherosclerotic burden assessed by artificial intelligence-based versus manual segmentation in 18F-sodium fluoride PET/CT scans: Head-to-head comparison

BACKGROUND

Artificial intelligence (AI) is known to provide effective means to accelerate and facilitate clinical and research processes. So in this study it was aimed to compare a AI-based method for cardiac segmentation in positron emission tomography/computed tomography (PET/CT) scans with manual segmentation to assess global cardiac atherosclerosis burden.

METHODS

A trained convolutional neural network (CNN) was used for cardiac segmentation in 18F-sodium fluoride PET/CT scans of 29 healthy volunteers and 20 angina pectoris patients and compared with manual segmentation. Parameters for segmented volume (Vol) and mean, maximal, and total standardized uptake values (SUVmean, SUVmax, SUVtotal) were analyzed by Bland-Altman Limits of Agreement. Repeatability with AI-based assessment of the same scans is 100%. Repeatability (same conditions, same operator) and reproducibility (same conditions, two different operators) of manual segmentation was examined by re-segmentation in 25 randomly selected scans.

RESULTS

Mean (± SD) values with manual vs. CNN-based segmentation were Vol 617.65 ± 154.99 mL vs 625.26 ± 153.55 mL (P = .21), SUVmean 0.69 ± 0.15 vs 0.69 ± 0.15 (P = .26), SUVmax 2.68 ± 0.86 vs 2.77 ± 1.05 (P = .34), and SUVtotal 425.51 ± 138.93 vs 427.91 ± 132.68 (P = .62). Limits of agreement were - 89.42 to 74.2, - 0.02 to 0.02, - 1.52 to 1.32, and - 68.02 to 63.21, respectively. Manual segmentation lasted typically 30 minutes vs about one minute with the CNN-based approach. The maximal deviation at manual re-segmentation was for the four parameters 0% to 0.5% with the same and 0% to 1% with different operators.

CONCLUSION

The CNN-based method was faster and provided values for Vol, SUVmean, SUVmax, and SUVtotal comparable to the manually obtained ones. This AI-based segmentation approach appears to offer a more reproducible and much faster substitute for slow and cumbersome manual segmentation of the heart.

Aortic wall segmentation in 18F-sodium fluoride PET/CT scans: Head-to-head comparison of artificial intelligence-based versus manual segmentation

BACKGROUND

We aimed to establish and test an automated AI-based method for rapid segmentation of the aortic wall in positron emission tomography/computed tomography (PET/CT) scans.

METHODS

For segmentation of the wall in three sections: the arch, thoracic, and abdominal aorta, we developed a tool based on a convolutional neural network (CNN), available on the Research Consortium for Medical Image Analysis (RECOMIA) platform, capable of segmenting 100 different labels in CT images. It was tested on 18F-sodium fluoride PET/CT scans of 49 subjects (29 healthy controls and 20 angina pectoris patients) and compared to data obtained by manual segmentation. The following derived parameters were compared using Bland-Altman Limits of Agreement: segmented volume, and maximal, mean, and total standardized uptake values (SUVmax, SUVmean, SUVtotal). The repeatability of the manual method was examined in 25 randomly selected scans.

RESULTS

CNN-derived values for volume, SUVmax, and SUVtotal were all slightly, i.e., 13-17%, lower than the corresponding manually obtained ones, whereas SUVmean values for the three aortic sections were virtually identical for the two methods. Manual segmentation lasted typically 1-2 hours per scan compared to about one minute with the CNN-based approach. The maximal deviation at repeat manual segmentation was 6%.

CONCLUSIONS

The automated CNN-based approach was much faster and provided parameters that were about 15% lower than the manually obtained values, except for SUVmean values, which were comparable. AI-based segmentation of the aorta already now appears as a trustworthy and fast alternative to slow and cumbersome manual segmentation.

Hedonic perception of odors in children aged 5-8 years is similar across 18 countries: Preliminary data

OBJECTIVE

Olfactory preference emerges very early in life, and the sense of smell in children rapidly develops until the second decade of life. It is still unclear whether hedonic perception of odors is shared in children inhabiting different regions of the globe.

METHODS

Five-hundred ten healthy children (N = 510; n_girls = 256; n_boys = 254) aged from 5 to 8 years from 18 countries rated the pleasantness of 17 odors.

RESULTS

The hedonic perception of odors in children aged between 5 and 8 years was rather consistent across 18 countries and mainly driven by the qualities of an odor and the overall ability of children to label odorants.

CONCLUSION

Conclusions from this study, being a secondary analysis, are limited to the presented set of odors that were initially selected for the development of U-Sniff test and present null findings for the cross-cultural variability in hedonic perception of odors across 18 countries. These two major issues should be addressed in the future to either contradict or replicate the results presented herewith. This research lays fundament for posing further research questions about the developmental aspects of hedonic perception of odors and opens a new door for investigating cross-cultural differences in chemosensory perception of children.

PET/CT imaging of spinal inflammation and microcalcification in patients with low back pain: A pilot study on the quantification by artificial intelligence-based segmentation

Background

Current imaging modalities are often incapable of identifying nociceptive sources of low back pain (LBP). We aimed to characterize these by means of positron emission tomography/computed tomography (PET/CT) of the lumbar spine region applying tracers ¹⁸F‐fluorodeoxyglucose (FDG) and ¹⁸F‐sodium fluoride (NaF) targeting inflammation and active microcalcification, respectively.

Methods

Using artificial intelligence (AI)‐based quantification, we compared PET findings in two sex‐ and age‐matched groups, a case group of seven males and five females, mean age 45 ± 14 years, with ongoing LBP and a similar control group of 12 pain‐free individuals. PET/CT scans were segmented into three distinct volumes of interest (VOIs): lumbar vertebral bodies, facet joints and intervertebral discs. Maximum, mean and total standardized uptake values (SUVmax, SUVmean and SUVtotal) for FDG and NaF uptake in the 3 VOIs were measured and compared between groups. Holm–Bonferroni correction was applied to adjust for multiple testing.

Results

FDG uptake was slightly higher in most locations of the LBP group including higher SUVmean in the intervertebral discs (0.96 ± 0.34 vs. 0.69 ± 0.15). All NaF uptake values were higher in cases, including higher SUVmax in the intervertebral discs (11.63 ± 3.29 vs. 9.45 ± 1.32) and facet joints (14.98 ± 6.55 vs. 10.60 ± 2.97).

Conclusion

Observed intergroup differences suggest acute inflammation and microcalcification as possible nociceptive causes of LBP. AI‐based quantification of relevant lumbar VOIs in PET/CT scans of LBP patients and controls appears to be feasible. These promising, early findings warrant further investigation and confirmation.

Analysis of mammograms using artificial intelligence to predict response to neoadjuvant chemotherapy in breast cancer patients: proof of concept

Objectives

In this proof of concept study, a deep learning–based method for automatic analysis of digital mammograms (DM) as a tool to aid in assessment of neoadjuvant chemotherapy (NACT) treatment response in breast cancer (BC) was examined.

Methods

Baseline DM from 453 patients receiving NACT between 2005 and 2019 were included in the study cohort. A deep learning system, using the aforementioned baseline DM, was developed to predict pathological complete response (pCR) in the surgical specimen after completion of NACT. Two image patches, one extracted around the detected tumour and the other from the corresponding position in the reference image, were fed into a classification network. For training and validation, 1485 images obtained from 400 patients were used, and the model was ultimately applied to a test set consisting of 53 patients.

Results

A total of 95 patients (21%) achieved pCR. The median patient age was 52.5 years (interquartile range 43.7–62.1), and 255 (56%) were premenopausal. The artificial intelligence (AI) model predicted the pCR as represented by the area under the curve of 0.71 (95% confidence interval 0.53–0.90; p = 0.035). The sensitivity was 46% at a fixed specificity of 90%.

Conclusions

Our study describes an AI platform using baseline DM to predict BC patients’ responses to NACT. The initial AI performance indicated the potential to aid in clinical decision-making. In order to continue exploring the clinical utility of AI in predicting responses to NACT for BC, further research, including refining the methodology and a larger sample size, is warranted.

Key Points

• We aimed to answer the following question: Prior to initiation of neoadjuvant chemotherapy, can artificial intelligence (AI) applied to digital mammograms (DM) predict breast tumour response?

• DMs contain information that AI can make use of for predicting pathological complete (pCR) response after neoadjuvant chemotherapy for breast cancer.

• By developing an AI system designed to focus on relevant parts of the DM, fully automatic pCR prediction can be done well enough to potentially aid in clinical decision-making.

Improving smoking cessation after myocardial infarction by systematically implementing evidence-based treatment methods: a prospective observational cohort study

Background

For smokers who suffer a myocardial infarction (MI), smoking cessation is the most effective measure to reduce recurrent event risk. Still, evidence-based treatment methods for aiding smoking cessation post-MI are underused.

Purpose

To compare the odds of smoking cessation at two-months post-MI before and after implementing a set of pre-specified routines for optimization of evidence-based treatment methods for smoking cessation, with start during admission.

Methods

Structured routines for early smoking cessation counselling and treatment optimization were implemented at six cardiac rehabilitation (CR) centres in Sweden. The routines included CR nurses providing current smokers hospitalized for acute MI with short consultation, written material, and optimal dosage of nicotine replacement therapy during admission, increasing early prescription of varenicline for eligible patients, and contacting the patients by telephone 3–5 days after discharge, after which usual care CR follow-up commenced. Centres were also encouraged to strive for continuity in nurse-patient care. Patient data was retrieved from the SWEDEHEART registry and medical records. Using logistic regression, we compared the odds for smoking cessation at two-months post-MI for currently smoking patients admitted with MI (a) before (n=188, median age 60 years, 23% females) and (b) after (n=195, median age 60 years, 29% females) routine implementation. Secondary outcomes included adherence to implemented routines and the association of each routine with smoking cessation odds at two-months.

Results

In total, 159 (85%) and 179 (92%) of enrolled patients attended the two-month CR follow-up, before and after implementation of the new routines. After implementation, a significantly larger proportion of patients (65% vs 54%) were abstinent from smoking at two-months (crude OR 1.60 [1.04–2.48], p=0.034) (Figure 1). Including only those counselled during admission (n=89), 74% (vs 54%) were abstinent at two-months (crude OR 2.50 [1.42–4.41], p=0.002). After the new routine implementation patients were counselled more frequently during admission (50% vs 6%, p<0.001), prescribed varenicline at discharge or during follow-up (23% vs 7%, p<0.001), and contacted by telephone during the first week post-discharge (18% vs 2%, p<0.001), compared to before implementation. Crude and adjusted associations between each routine and smoking cessation at two-months are shown in Table 1. Entering all routines into the regression model simultaneously, being prescribed varenicline before discharge or during follow-up had the strongest independent association with smoking abstinence at two-months (adjusted OR 4.09 [1.68–10.00], p=0.002).

Conclusion

Our results support that readily available methods for aiding smoking cessation can be implemented effectively in routine practice, with possible beneficial effects on smoking cessation for the high-risk group of smoking MI patients.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): The Swedish Heart and Lung AssociationPfizer AB

Admission screening and cohort care decrease carbapenem resistant enterobacteriaceae in Vietnamese pediatric ICU's

Objectives

To assess if admission screening for Carbapenem Resistant Enterobacteriaceae (CRE) and cohort care can reduce CRE acquisition (CRE colonization during hospital stay), Hospital Acquired Infections (HAI), hospital-stay, mortality, and costs in three Intensive Care Units (ICU’s) at the Vietnamese National Children’s Hospital.

Method

CRE screening using rectal swabs and ChromIDCarbas elective culture at admission and if CRE negative, once weekly. Patients were treated in cohorts based on CRE colonization status.

Results

CRE colonization at baseline point-prevalence screening was 76.9% (103/134). Of 941 CRE screened at admission, 337 (35.8%) were CREpos. 694 patients met inclusion criteria. The 244 patients CRE negative at admission and screened > 2 times were stratified in 8 similar size groups (periods), based on time of admission. CRE acquisition decreased significant (OR − 3.2, p < 0.005) from 90% in period 2 (highest) to 48% in period 8 (last period). Patients with CRE acquisition compared to no CRE acquisition had a significantly higher rate of culture confirmed HAI, n = 20 (14%) vs. n = 2 (2%), longer hospital stays, 3.26 vs. 2.37 weeks, and higher total treatment costs, 2852 vs. 2295 USD.

Conclusion

Admission CRE screening and cohort care in pediatric ICU’s significantly decreased CRE acquisition, cases of HAI and duration of hospital-stay.

Pneumococcal carriage among children aged 4 - 12 years in Angola 4 years after the introduction of a pneumococcal conjugate vaccine

Children in Angola are affected by a high burden of disease caused by pneumococcal infections. The 13-valent pneumococcal conjugate vaccine (PCV13) was introduced in the childhood immunization programme in 2013 but the serotype distribution of Streptococcus pneumoniae and antimicrobial susceptibility patterns are unknown. We did a cross-sectional nasopharyngeal carriage study in Luanda and Saurimo, Angola (PCV13 3rd dose coverage 67% and 84%, respectively) during November to December 2017 comprising 940 children aged 4-12 years. The main objective was to assess vaccine serotype coverage and antimicrobial susceptibility rates for S. pneumoniae. Our secondary aim was to characterize colonizinig strains of Haemophilus influenzae and Moraxella catarrhalis. Pneumococcal colonization was found in 35% (95% CI 32-39%) of children (n = 332), with 41% of serotypes covered by PCV13. The most common serotypes were 3 (8%), 18C (6%), 23F (6%), 11A (6%), 34 (6%), 19F (5%) and 16 (5%). Carriage of H. influenzae and M. catarrhalis was detected in 13% (95% CI 11-15%) and 15% (95% CI 13-17%) of children, respectively. Non-susceptibility to penicillin was common among pneumococci (40%), particularly among PCV13-included serotypes (50% vs. 33%; p = 0.003), although the median minimal inhibitory concentration was low (0.19 µg/mL, IQR 0.13-0.25 µg/mL). Most pneumococci and H. influenzae were susceptible to amoxicillin (99% and 88%, respectively). Furthermore, resistance to trimethoprim-sulfamethoxazole was>70% among all three species. Multidrug-resistant pneumococci (non-susceptible to ≥ 3 antibiotics; 7% [n = 24]) were further studied with whole genome sequencing to investigate clonality as an underlying cause for this phenotype. No clearly dominating clone(s) were, however, detected. The results indicate that continued use of PCV13 may have positive direct and herd effects on pneumococcal infections in Angola as carriage of vaccine serotypes was common in the non-vaccinated age group. Finally, amoxicillin is assessed to be a feasible empirical treatment of respiratory tract infections in Angola.

Artificial intelligence-based detection of lymph node metastases by PET/CT predicts prostate cancer-specific survival

INTRODUCTION

Lymph node metastases are a key prognostic factor in prostate cancer (PCa), but detecting lymph node lesions from PET/CT images is a subjective process resulting in inter-reader variability. Artificial intelligence (AI)-based methods can provide an objective image analysis. We aimed at developing and validating an AI-based tool for detection of lymph node lesions.

METHODS

A group of 399 patients with biopsy-proven PCa who had undergone ¹⁸ F-choline PET/CT for staging prior to treatment were used to train (n = 319) and test (n = 80) the AI-based tool. The tool consisted of convolutional neural networks using complete PET/CT scans as inputs. In the test set, the AI-based lymph node detections were compared to those of two independent readers. The association with PCa-specific survival was investigated.

RESULTS

The AI-based tool detected more lymph node lesions than Reader B (98 vs. 87/117; p = .045) using Reader A as reference. AI-based tool and Reader A showed similar performance (90 vs. 87/111; p = .63) using Reader B as reference. The number of lymph node lesions detected by the AI-based tool, PSA, and curative treatment was significantly associated with PCa-specific survival.

CONCLUSION

This study shows the feasibility of using an AI-based tool for automated and objective interpretation of PET/CT images that can provide assessments of lymph node lesions comparable with that of experienced readers and prognostic information in PCa patients.

Consequences of undetected olfactory loss for human chemosensory communication and well-being

Olfactory perception has implications for human chemosensory communication and in a broader context, it affects well-being. However, most of the studies investigating the consequences of olfactory loss have recruited patients who have already been categorized as having a dysfunctional sense of smell and sought help in an ENT clinic. We revisit these findings by distinguishing subjects with olfactory impairment from a group of subjects who all declared a normal sense of smell when enrolling for this study. In the initial sample of 203 individuals, we found 59 to have impaired olfaction and four with marginal olfactory performance, not useful in daily life. Interestingly, we found a significant between-group difference in cognitive functioning, further supporting the notion of the relationship between cognition and olfactory performance. However, their chemosensory communication and well-being appeared not to be different from subjects with normosmia. Impaired olfactory function certainly has a severe impact on daily life but more so in individuals who are bothered with it and decide to seek treatment. The limited-to-no olfactory perception in the fraction of subjects who neither complain about it nor seek help in ENT clinics does not seem to have a major effect on their social, cognitive, emotional and health functioning. This article is part of the Theo Murphy meeting issue 'Olfactory communication in humans'.

Health-promoting factors in higher education for a sustainable working life - protocol for a multicenter longitudinal study

BACKGROUND

The World Health Organization has highlighted the importance of health promotion for health service providers in order to ensure sustainable working life for individuals involved in providing health services. Such sustainability begins when students are preparing to manage their own future health and welfare in working life. It has been suggested that universities, employees and trainee health professionals should adopt or follow a salutogenic approach that not only complements the providing of information on known health risks but also favors health promotion strategies. This paper describes the study design and data collection methods in a planned study aiming to explore health-promoting factors for a sustainable working life among students in higher education within healthcare and social work.

METHODS

This protocol describes a multicenter longitudinal study involving Swedish students on higher education programs in the healthcare and social work sectors. In 2018, the study invited students on seven education programs at six universities to participate. These programs were for qualification as: biomedical laboratory scientists (n = 121); dental hygienists (n = 87); nurses (n = 1411); occupational therapists (n = 111); physiotherapists (n = 48); radiographers (n = 60); and, social workers (n = 443). In total, 2283 students were invited to participate. Participants completed a baseline, a self-reported questionnaire including six validated instruments measuring health-promoting factors and processes. There are to be five follow-up questionnaires. Three while the students are studying, one a year after graduating, and one three years after graduating. Each questionnaire captures different health-promoting dimensions, namely: health-promoting resources (i.e. sense of coherence); occupational balance; emotional intelligence; health and welfare; social interaction; and work and workplace experiences/perceptions.

DISCUSSION

This study focuses on the vastly important aspect of promoting a sustainable working life for healthcare and social work employees. In contrast to previous studies in this area, the present study uses different, validated instruments in health promotion, taking a salutogenic approach. It is hoped that, by stimulating the implementation of new strategies, the study's findings will lead to education programs that prepare students better for a sustainable working life in healthcare and social work.

Abstract P4-14-06: A study of adverse vascular effects of adjuvant therapy with aromatase inhibitors in women with breast cancer

Background: There is a debate concerning risk of cardiovascular disease (CVD) from adjuvant therapy with aromatase inhibitors (AI). Randomized trials have indicated higher CV risk and one observational study higher risk of myocardial infarction, whereas other studies have pointed out no elevated risk. The first morphological sign of developing atherosclerosis is a thickening of the arterial intima layer, whereas in the longer perspective the media layer gets thinner - a process not captured when using conventional Carotid intima-media-thickness (CIMT). We therefore used high resolution ultrasound (HRU), to separately estimated the intima and media layers and calculate the I/M thickness ratio. A thicker intima and higher I/M thickness ratio are signs of adverse vascular effects. This principle of estimating vascular aging can strongly distinguish 70-yr old subjects with and w/o prevalent CVD, yielding C-values up to 0.90 in ROC-analysis.

Patients and Methods: We included 150 postmenopausal breast cancer women of whom 50 were treated with AI during at least 3 years, 50 with at least 3 years of tamoxifen and 50 were without endocrine therapy. Patients were investigated with non-invasive HRU (22MHz) of the common carotid artery (CCA). Non-parametric statistical methods were used, including Bootstrap quantile regression to obtain 95% confidence intervals (CI) and adjustment for potential confounders: age, smoking, use of statins, HbA1c and previous HRT.

Results: Of 150 included women, 132 remained having a technically acceptable ultra sound scans and no AI therapy before tamoxifen therapy; AI (#48); tamoxifen (#40) and no anti-hormone therapy (#44). Corresponding median ages were 66, 65 and 65 yrs and median treatment durations were 54 (AI) and 58 (tamoxifen) months.

AI therapy, compared to tamoxifen, showed a significantly thicker CCA-intima layer, p = 0.031. However, mean values of both CCA-intima thickness and I/M thickness ratio were very similar in the tamoxifen and the no anti-estrogen group; Thus, AI compared to the other two groups combined, had a significantly thicker intima layer (p = 0.009) and higher I/M ratio (p = 0.047), both indicating adverse vascular effects from AI therapy. After adjustment for potential confounders, AI therapy still showed a thicker CCA intima layer of 0.015 mm (95% CI .003, .027); p = 0.016.

In contrast, corresponding analysis using conventional Carotid intima-media thickness (CIMT), revealed no significant group differences or association to AI treatment duration.

Conclusion: More than three years of adjuvant therapy with aromatase inhibitors, compared to women having no anti-estrogen therapy or tamoxifen, was associated with signs of adverse vascular effects; thicker intima layer and higher intima/media ratio of the common carotid artery. After adjustment, the thicker intima layer remained significant. These findings are in accordance with reports of increased risk of cardiovascular events following adjuvant therapy with aromatase inhibitors.

Citation Format: Lindman H, Dahlberg L, Larsson M, Naessén T. A study of adverse vascular effects of adjuvant therapy with aromatase inhibitors in women with breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-14-06.

Low-Energy Collisions of Protonated Enantiopure Amino Acids with Chiral Target Gases

Here we report on the gas-phase interactions between protonated enantiopure amino acids (L- and D-enantiomers of Met, Phe, and Trp) and chiral target gases [(R)- and (S)-2-butanol, and (S)-1-phenylethanol] in 0.1-10.0 eV low-energy collisions. Two major processes are seen to occur over this collision energy regime, collision-induced dissociation and ion-molecule complex formation. Both processes were found to be independent of the stereo-chemical composition of the interacting ions and targets. These data shed light on the currently debated mechanisms of gas-phase chiral selectivity by demonstrating the inapplicability of the three-point model to these interactions, at least under single collision conditions. Graphical Abstract.

Association between angiogenic factors and signs of arterial aging in women with pre-eclampsia

OBJECTIVE

Pre-eclampsia (PE) is associated with an increased risk of cardiovascular disease later in life. In cases with PE there is a substantial increase in levels of the antiangiogenic factor soluble fms-like tyrosine kinase-1 (sFlt-1) and decreased levels of the proangiogenic factor placental growth factor (PlGF). Elevated levels of sFlt-1 are also found in individuals with cardiovascular disease. The aims of this study were to assess levels of sFlt-1, PlGF and the sFlt-1/PlGF ratio and their correlation with signs of arterial aging by measuring the common carotid artery (CCA) intima and media thicknesses and their ratio (I/M ratio) in women with and without PE.

METHODS

Serum sFlt-1 and PlGF levels were measured using commercially available enzyme-linked immunosorbent assay kits, and CCA intima and media thicknesses were estimated using high-frequency (22-MHz) ultrasonography in 55 women at PE diagnosis and in 64 women with normal pregnancy at a similar gestational age, with reassessment at 1 year postpartum.

RESULTS

During pregnancy, higher levels of sFlt-1, lower levels of PlGF, a thicker intima, a thinner media and a higher I/M ratio of the CCA were found in women with PE vs controls (all P < 0.0001). Further, sFlt-1 and the sFlt-1/PlGF ratio were positively correlated with intima thickness and I/M ratio (all P < 0.0001). At 1 year postpartum, levels of sFlt-1 and the sFlt-1/PlGF ratio had decreased in both groups; however, their levels in the PE group were still higher than in the controls (P = 0.001 and < 0.0001, respectively). Levels of sFlt-1 and the sFlt-1/PlGF ratio remained positively correlated with intima thickness and I/M ratio at 1 year postpartum.

CONCLUSIONS

Higher sFlt-1 levels and sFlt-1/PlGF ratio in women with PE were positively associated with signs of arterial aging during pregnancy. At 1 year postpartum, sFlt-1 levels and the sFlt-1/PlGF ratio were still higher in the PE group and were associated with the degree of arterial aging. © 2016 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.

Caretakers' barriers to pediatric antiretroviral therapy adherence in Vietnam - A qualitative and quantitative study

BACKGROUND

Poor antiretroviral therapy (ART) adherence leads to drug resistance and treatment failures. The options for second and third line ART regimens, particularly for pediatric patients, are very limited in low and middle-income countries. HIV-infected children are mostly passive drug-takers, thus caretakers play a very important role in assuring ART adherence. Pediatric ART adherence is still a challenging problem in Vietnam since non-adherence is the major risk factor for treatment failure. Our study explores and measures caretakers' barriers in order to improve pediatric ART adherence in future.

METHODS

Exploring caretakers' barriers was conducted through a qualitative study with Focus Group Discussion (FGD) on two topics: 1. Current society - family support and difficulties in taking care children under ART; 2. Stigma experience. Based on the finding from the qualitative study a quantitative study measuring caretakers' barriers was conducted through a designed questionnaire. Study methods strictly followed the consolidated criteria with 32-item checklist for interviews and focus groups.

RESULTS

In total eight FGDs with 53 participants were conducted. Common caretakers' barriers to children's ART adherence, were financial burden, lack of ART KP (Knowledge-Practice), stigma, depression, shifting caretaker, drug taste and side effects, lack of family support, fixed health check-up schedule and HIV non-disclosure. In the questionnaire study a total of 209 caretakers participated. The most commonly reported caretakers' barriers were: financial burden (144; 69%), KP burden (143; 68%), depression (85; 41%) and stigma (30; 14.8%). Some caretakers' characteristics that significantly associated with reported barriers (p<0.05). Rural caretakers reported significantly more financial burden (OR=2.26) and stigma (OR=3.53) than urban. Caretakers with under high school level education reported significantly more financial burdens (OR=2.08) and stigma (OR=4.15) compared to caretakers with high school education or over.

CONCLUSION

Financial burden, KP burden, depression and stigma were common reported caretakers' barriers to pediatric ART adherence. Family residence, caretaker's education level and job were considered as the key factors determining caretakers' barriers related to financial burden and stigma. These findings may be important for policy makers and researchers in order to develop effective interventions regarding to caretakers' burdens and associated factors. Furthermore, a tool for nurses in monitoring caretakers' barriers to pediatric ART adherence was developed first with FDG, and then interview questionnaire. This tool could be applied and modified easily in any pediatric ART clinic settings in accordance to economic, social and cultural circumstances.

Signatures of Hyperfine, Spin-Orbit, and Decoherence Effects in a Pauli Spin Blockade

We detect in real time interdot tunneling events in a weakly coupled two-electron double quantum dot in GaAs. At finite magnetic fields, we observe two characteristic tunneling times T_{d} and T_{b}, belonging to, respectively, a direct and a blocked (spin-flip-assisted) tunneling. The latter corresponds to the lifting of a Pauli spin blockade, and the tunneling times ratio η=T_{b}/T_{d} characterizes the blockade efficiency. We find pronounced changes in the behavior of η upon increasing the magnetic field, with η increasing, saturating, and increasing again. We explain this behavior as due to the crossover of the dominant blockade-lifting mechanism from the hyperfine to spin-orbit interactions and due to a change in the contribution of the charge decoherence.

A genome-wide association study of kynurenic acid in cerebrospinal fluid: implications for psychosis and cognitive impairment in bipolar disorder

Elevated cerebrospinal fluid (CSF) levels of the glia-derived N-methyl-D-aspartic acid receptor antagonist kynurenic acid (KYNA) have consistently been implicated in schizophrenia and bipolar disorder. Here, we conducted a genome-wide association study based on CSF KYNA in bipolar disorder and found support for an association with a common variant within 1p21.3. After replication in an independent cohort, we linked this genetic variant-associated with reduced SNX7 expression-to positive psychotic symptoms and executive function deficits in bipolar disorder. A series of post-mortem brain tissue and in vitro experiments suggested SNX7 downregulation to result in a caspase-8-driven activation of interleukin-1β and a subsequent induction of the brain kynurenine pathway. The current study demonstrates the potential of using biomarkers in genetic studies of psychiatric disorders, and may help to identify novel drug targets in bipolar disorder.

Gliptin-mediated neuroprotection against stroke requires chronic pretreatment and is independent of glucagon-like peptide-1 receptor

Gliptins are anti-type 2 diabetes (T2D) drugs that regulate glycaemia by preventing endogenous glucagon-like peptide-1 (GLP-1) degradation. Chronically administered gliptins before experimental stroke can also induce neuroprotection, and this effect is potentially relevant for reducing brain damage in patients with T2D and high risk of stroke. It is not known, however, whether acute gliptin treatment after stroke (mimicking a post-hospitalization treatment) is neuroprotective or whether gliptin-mediated neuroprotection occurs via GLP-1-receptor (GLP-1R) activation. To answer these two questions, wild-type and glp-1r(-/-) mice were subjected to transient middle cerebral artery occlusion (MCAO). Linagliptin was administered acutely (50 mg/kg intravenously), at MCAO time or chronically (10 mg/kg orally) for 4 weeks before and 3 weeks after MCAO. Neuroprotection was assessed by stroke volume measurement and quantification of NeuN-positive surviving neurons. Plasma/brain GLP-1 levels and dipeptidyl peptidase-4 activity were also measured. The results show that the linagliptin-mediated neuroprotection against stroke requires chronic pretreatment and does not occur via GLP-1R. The findings provide essential new knowledge with regard to the potential clinical use of gliptins against stroke, as well as a strong impetus to identify gliptin-mediated neuroprotective mechanisms.

Midwives' adoption of the reproductive life plan in contraceptive counselling: a mixed methods study

STUDY QUESTION

How is the reproductive life plan (RLP) adopted in midwifery contraceptive counselling?

SUMMARY ANSWER

A majority of midwives adopted the RLP in their counselling, had predominantly positive experiences and considered it a feasible tool for promoting reproductive health.

WHAT IS KNOWN ALREADY

The RLP is a health-promoting tool recommended by the Centers for Disease Control and Prevention in the USA for improving preconception health. It was recently used in a clinical setting in Sweden and was found to increase women's knowledge about fertility and to influence women's wishes to have their last child earlier in life.

STUDY DESIGN, SIZE, DURATION

An exploratory mixed methods study among 68 midwives who provided contraceptive counselling in primary health care to at least 20 women each during the study period. Midwives received an introduction and materials for using the RLP in contraceptive counselling. Three months later, in the spring of 2014, they were invited to complete a questionnaire and participate in a focus group interview about their adoption of the RLP.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Data collection was through a questionnaire (n = 53 out of 68; participation rate 78%) and five focus group interviews (n = 22). Participants included both younger and older midwives with longer and shorter experiences of contraceptive counselling in public and private health care in one Swedish county. Quantitative data were analysed for differences between users and non-users, and qualitative data were analysed by qualitative content analysis to explore the midwives experiences and opinions of using the RLP.

MAIN RESULTS AND THE ROLE OF CHANCE

Sixty-eight per cent of midwives had used the RLP in their contraceptive counselling. Four categories emerged through the focus group interviews: (i) A predominantly positive experience; (ii) The RLP-a health-promoting tool; (iii) individual and societal factors influence the RLP counselling; and (4) long-term implementation comprises opportunities, risks and needs. The most common reason for not using the RLP was lack of information.

LIMITATIONS, REASONS FOR CAUTION

There was general lack of experience of using the RLP with women from different cultural backgrounds, with non-Swedish speaking women and, when a partner was present. Due to the non-random sample, the limited knowledge about non-responders and a short follow-up period, results apply to short-term implementations and might not fully apply to long-term implementation.

WIDER IMPLICATIONS OF THE FINDINGS

The use of RLP in contraceptive counselling appears a feasible way of promoting reproductive health. Results from the USA and Sweden indicate it is a promising tool for midwives and other health professionals involved in reproductive counselling, which deserves to be explored in other nations.

STUDY FUNDING/COMPETING INTERESTS

Grants were received from the Medical Faculty at Uppsala University and the European Society of Contraception and Reproductive Health. There are no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

The neurobiology of eating disorders--a clinical perspective

OBJECTIVE

To provide a neurobiological basis of eating disorders for clinicians and to enlighten how comparing neurobiology and eating disorders with neurobiology of other psychiatric illnesses can improve treatment protocols.

METHOD

A selective review on the neurobiology of eating disorders. The article focuses on clinical research on humans with consideration of the anatomical, neural, and molecular basis of eating disorders.

RESULTS

The neurobiology of people with eating disorders is altered. Many of the neurobiological regions, receptors, and chemical substrates that are affected in other mental illnesses also play an important role in eating disorders. More knowledge about the neurobiological overlap between eating disorders and other psychiatric populations will help when developing treatment protocols not the least regarding that comorbidity is common in patients with EDs.

CONCLUSION

Knowledge about the underlying neurobiology of eating disorders will improve treatment intervention and will benefit from comparisons with other mental illnesses and their treatments.

Effectiveness of implant therapy analyzed in a Swedish population: early and late implant loss

Treatment outcomes in implant dentistry have been mainly assessed as implant survival rates in small, selected patient groups of specialist or university clinical settings. This study reports on loss of dental implants assessed in a large and randomly selected patient sample. The results were aimed at representing evaluation of effectiveness of implant dentistry. Using the national data register of the Swedish Social Insurance Agency, 4,716 patients were randomly selected. All had been provided with implant-supported restorative therapy in 2003. Patient files of 2,765 patients (11,311 implants) were collected from more than 800 clinicians. Information on patients, treatment procedures, and outcomes related to the implant-supported restorative therapy was extracted from the files. In total, 596 of the 2,765 subjects, provided with 2,367 implants, attended a clinical examination 9 y after therapy. Implant loss that occurred prior to connection of the supraconstruction was scored as an early implant loss, while later occurring loss was considered late implant loss. Early implant loss occurred in 4.4% of patients (1.4% of implants), while 4.2% of the patients who were examined 9 y after therapy presented with late implant loss (2.0% of implants). Overall, 7.6% of the patients had lost at least 1 implant. Multilevel analysis revealed higher odds ratios for early implant loss among smokers and patients with an initial diagnosis of periodontitis. Implants shorter than 10 mm and representing certain brands also showed higher odds ratios for early implant loss. Implant brand also influenced late implant loss. Implant loss is not an uncommon event, and patient and implant characteristics influence outcomes (ClinicalTrials.gov NCT01825772).

Parity independence of the zero-bias conductance peak in a nanowire based topological superconductor-quantum dot hybrid device

We explore the signatures of Majorana fermions in a nanowire based topological superconductor-quantum dot-topological superconductor hybrid device by charge transport measurements. At zero magnetic field, well-defined Coulomb diamonds and the Kondo effect are observed. Under the application of a finite, sufficiently strong magnetic field, a zero-bias conductance peak structure is observed. It is found that the zero-bias conductance peak is present in many consecutive Coulomb diamonds, irrespective of the even-odd parity of the quasi-particle occupation number in the quantum dot. In addition, we find that the zero-bias conductance peak is in most cases accompanied by two differential conductance peaks, forming a triple-peak structure, and the separation between the two side peaks in bias voltage shows oscillations closely correlated to the background Coulomb conductance oscillations of the device. The observed zero-bias conductance peak and the associated triple-peak structure are in line with Majorana fermion physics in such a hybrid topological system.