[Lung transplantation: current situation and developments]

Lung transplantation is currently the gold standard treatment for end-stage lung diseases. Advances in the preservation of donor lungs, the surgical technique and immunosuppressive therapy have led to lung transplantation now being a routine procedure. Nevertheless, the shortage of donor organs, the acute and particularly chronic lung allograft dysfunction (CLAD) still represent major challenges even in experienced centers. Research in this area is still necessary to improve the long-term survival of lung recipients.

Evaluation of treatment delays in hepatopancreatico-biliary surgery during the first COVID-19 wave

INTRODUCTION

The COVID-19 pandemic has caused oncological services worldwide to face unprecedented challenges resulting in treatment disruption for surgical patients. Hepatopancreatico-biliary (HPB) cancers are characterised by rapid disease progression. This study aims to assess delays in receiving surgery for this patient cohort during the first COVID-19 wave.

METHODS

Patients undergoing surgery between April and July 2020 (COVID-19 period) were compared with a control group from the preceding year. Delay in receiving surgery was defined as more than 50 days between referral and surgery date. Statistical analysis was carried out to evaluate predictors of delay and short-term outcomes.

RESULTS

During the COVID-19 and pre-COVID-19 periods, 94 and 115 patients underwent surgery, respectively. No patients contracted COVID-19 postoperatively. Some 118 patients waited more than 50 days for surgery versus 91 who received surgery within 50 days from referral. Independent predictors for surgical delay were undergoing surgery in the COVID-19 era (odds ratio (OR) 2.2, 95% confidence interval (CI) 1.2-4.1; p=0.015), referral pathway (OR 35.1, 95% CI 4.2-296; p=0.001) and presenting pathology (OR 8.3, 95% CI 1.2-56.1; p=0.03). Short-term outcomes were comparable between groups.

CONCLUSIONS

Patient referral pathway and presenting pathology may contribute to delays in undergoing HPB cancer surgery during COVID-19 outbreaks. It is hoped that a better understanding of these factors will aid in designing shifts in healthcare policy during future pandemic outbreaks.

Predictors of recurrence following laparoscopic minor hepatectomy for hepatocellular carcinoma in the UK

AIMS

Minor hepatectomy, which is increasingly carried out laparoscopically (LLR), is a cornerstone of curative treatment for hepatocellular carcinoma (HCC). The majority of relevant publications however originate from regions with endemic viral hepatitis. Although the incidence of HCC in the UK is increasing, little is known about outcomes following LLR.

METHODS

Consecutive patients undergoing minor (involving ≤2 segments) LLR or open resection (OLR) at our institute between 2014 and 2021 were compared. Selection from a plethora of factors potentially impacting on overall (OS) and disease free survival (DFS) was optimised with Lasso regression. To enable analysis of patients having repeat resection, multivariate frailty modelling was utilised to calculate hazard ratios (HR).

RESULTS

The analysis of 111 liver resections included 55 LLR and 56 OLR. LLR was associated with a shorter hospital stay (5 ± 2 vs. 7 ± 2 days; p < 0.001) and a lower comprehensive complication index (4.43 vs. 9.96; p = 0.006). Mean OS (52.3 ± 2.3 vs. 49.9 ± 3.0 months) and DFS (33.9 ± 3.4 vs. 36.5 ± 3.6 months; p = 0.59) were comparable between LLR and OLR, respectively (median not reached). Presence of mixed cholangiocarcinoma/HCC, satellite lesions and AFP level predicted OS and DFS. In addition tumour size was predictive of DFS.

CONCLUSIONS

In the studied population minor LLR was associated with shorter hospital stay and fewer complications while offering non-inferior long-term outcomes. A number of predictors for disease free survival have been elucidated that may aid in identifying patients with a high risk of disease recurrence and need for further treatment.

Associations between prenatal exposure to power plants and birth outcomes across the United States

OBJECTIVES

Although there is growing evidence that in utero exposure to power plants increases the risk of adverse birth outcomes, studies have focused on coal-fired plants and single US locations, limiting generalizability. We used birth certificate data from 50 states and DC to examine the associations between prenatal exposure to power plants and birth outcomes overall and by race/ethnicity.

METHODS

We linked 2009-2018 county-level microdata natality files on 34,674,911 singleton births from 50 states and DC with 9-month county-level averages of power plant fuel consumption based on month/year of birth. We estimated linear regression models for birth weight and gestational age and probit models for the dichotomous outcomes of low birth weight, small for gestational age (SGA), and preterm birth. We subsequently examined interactions between plant fuel consumption and race/ethnicity.

RESULTS

Overall, 69.1% of counties had any power plant fuel consumption. Although we found no overall effects of prenatal exposure to power plants on birth weight or SGA, a significant interaction (both P < 0.01) revealed that a 10% increase in fuel consumption was associated with infants born to White women having slightly lower birth weights (1.76 g; 95% confidence interval = -2.87, -0.65) and higher risk of being born SGA (0.0002; 95% confidence interval = 0.0002, 0.0002).

CONCLUSION

Power plants have negative effects on infant health, which exist independent of locality.

Enhancing Ground-State Population and Macroscopic Coherence of Room-Temperature WS_{2} Polaritons through Engineered Confinement

Exciton polaritons (polaritons herein) in transition-metal dichalcogenide monolayers have attracted significant attention due to their potential for polariton-based optoelectronics. Many of the proposed applications rely on the ability to trap polaritons and to reach macroscopic occupation of their ground energy state. Here, we engineer a trap for room-temperature polaritons in an all-dielectric optical microcavity by locally increasing the interactions between the WS_{2} excitons and cavity photons. The resulting confinement enhances the population and the first-order coherence of the polaritons in the ground state, with the latter effect related to dramatic suppression of disorder-induced inhomogeneous dephasing. We also demonstrate efficient population transfer into the trap when optically injecting free polaritons outside of its periphery.

[Epidemiology and surgical treatment of pancreatic cancer in the State of Brandenburg : Analysis of 5418 cases]

BACKGROUND

Pancreatic cancer is the second most frequent cause of death among all forms of cancer in Germany with more than 19,000 deaths per year. The evaluation of the nationwide clinical cancer register aims to depict the reality of treatment and to improve the quality of treatment in the future by targeted analyses.

METHOD

The data from the clinical cancer register of Brandenburg-Berlin for the diagnosis years 2001-2017 were analyzed with respect to the treatment of pancreatic cancer. Data from patients resident in the State of Brandenburg were evaluated with respect to epidemiological and therapeutic parameters.

RESULTS

A total of 5418 patients with pancreatic cancer were documented in the register from 2001 to 2017 and 49.6% of the patients were diagnosed as having the Union for International Cancer Control (UICC) stage IV. A pancreas resection was carried out in 26.4% of the cases. In cases of cancer of the head of the pancreas the most frequent procedure was a pylorus-preserving resection with 51.8% and a pancreatectomy was carried out in 9.4%. The R0 resection rate of all pancreatic cancers in the period from 2014 to 2017 was 61.9%. After R0 resection the 5‑year survival was 19%. Relevant multivariate survival factors were age, UICC stage and the residual (R) tumor classification. The case numbers per hospital had no influence on the absolute survival of patients operated on in the State of Brandenburg.

CONCLUSION

The treatment reality in the State of Brandenburg for patients with pancreatic cancer corresponds to the results of international publications with respect to the key performance indicators investigated. A qualitative internationally comparable treatment of these patients is also possible in nonmetropolitan regions.

Facilitators and barriers to centre- and home-based exercise training in breast cancer patients - a swiss tertiary centre experience

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Swiss Cancer Research

Background

Exercise is an effective therapy for cancer patients to reduce fatigue and to improve health-related quality of life and physical function. Yet, cancer patients often do not meet physical activity guidelines.

Purpose

To understand why recommendations are not met, we aimed at identifying facilitators and barriers to supervised, centre-based exercise within a cardio-oncologic rehabilitation (CORE) programme and to unsupervised, home-based exercise as well as strategies used to manage these barriers.

Methods

Breast cancer patients who had completed a CORE programme at a Swiss tertiary centre were recruited. Semi-structured interviews were conducted with subsequent thematic analysis.

Results

Of 37 eligible breast cancer patients, 19 patients (mean age 48.9±9.7 years) participated to our invitation. Facilitators for centre-based exercise were social support, committedness and provision of structured exercise. Barriers towards centre-based exercise included physical and environmental barriers, while psychological barriers were reported predominantly for home-based exercise. Strategies to manage barriers included the adaptation of training circumstances, behaviour change strategies and strategies to deal with side effects.

Conclusions

Our results support the importance of providing CORE programmes and suggest that a special focus should be directed at the transition from supervised to self-organized exercise in order to enhance long-term exercise participation.

Crossover from exciton-polariton condensation to photon lasing in an optical trap

Optical trapping has been proven to be an effective method of separating exciton-polariton condensates from the incoherent high-energy excitonic reservoir located at the pumping laser position. This technique has significantly improved the coherent properties of exciton-polariton condensates, when compared to a quasi-homogeneous spot excitation scheme. Here, we compare two experimental methods on a sample, where a single spot excitation experiment allowed us only to observe photonic lasing in the weak coupling regime. In contrast, the ring-shaped excitation resulted in the two-threshold behavior, where an exciton-polariton condensate manifests itself at the first and photon lasing at the second threshold. Both lasing regimes are trapped in an optical potential created by the pump. We interpret the origin of this confining potential in terms of repulsive interactions of polaritons with the reservoir at the first threshold and as a result of the excessive free-carrier induced refractive index change of the microcavity at the second threshold. This observation offers a way to achieve multiple phases of photonic condensates in samples, e.g., containing novel materials as an active layer, where two-threshold behavior is impossible to achieve with a single excitation spot.

Effect of transcutaneous electrical nerve stimulation (TENS) on knee pain and physical function in patients with symptomatic knee osteoarthritis: the ETRELKA randomized clinical trial

OBJECTIVE

To determine the effectiveness of TENS at relieving pain and improving physical function as compared to placebo TENS, and to determine its safety, in patients with knee osteoarthritis.

METHODS

Multi-centre, parallel, 1:1 randomized, double-blind, placebo-controlled clinical trial conducted in six outpatient clinics in Switzerland. We included 220 participants with knee osteoarthritis recruited between October 15, 2012, and October 15, 2014. Patients were randomized to 3 weeks of treatment with TENS (n = 108) or placebo TENS (n = 112). Our pre-specified primary endpoint was knee pain at the end of 3-weeks treatment assessed with the WOMAC pain subscale. Secondary outcome measures included WOMAC physical function subscale and safety outcomes.

RESULTS

There was no difference between TENS and placebo TENS in WOMAC pain at the end of treatment (mean difference -0.06; 95%CI -0.41 to 0.29; P = 0.74), nor throughout the trial duration (P = 0.98). Subgroup analyses did not indicate an interaction between patient/treatment characteristics and treatment effect on WOMAC pain at the end of treatment (P-interaction ≥0.22). The occurrence of adverse events was similar across groups, with 10.4% and 10.6% of patients reporting events in the TENS and placebo TENS groups, respectively (P = 0.95). No relevant differences were observed in secondary outcomes.

CONCLUSIONS

TENS does not improve knee osteoarthritis pain when compared to placebo TENS. Therapists should consider other potentially more effective treatment modalities to decrease knee osteoarthritis pain and facilitate strengthening and aerobic exercise. Our findings are conclusive and further trials comparing TENS and placebo TENS in this patient population are not necessary.

A Pilot Observational Exploratory Study of Well-Being in Hospice Interdisciplinary Team Members

INTRODUCTION

Well-being and turnover intent represent key aspects to the promotion of a healthy workforce. Alarming levels of burnout and low levels of well-being have been documented in health professionals across care settings. Not only do high levels of burnout, low well-being and high turnover affect health professionals, but they are associated with poor patient care. However, limited research has investigated this topic specifically in hospice interdisciplinary team (IDT) members, nurses, chaplains, social workers. Thus, the purpose of this study was to explore hospice IDT members' well-being, and turnover intent.

METHODS

This observational, pilot study used quantitative surveys to examine the well-being, and turnover intention at baseline and at 3 months. Twenty-five hospice IDT members at one site participated.

RESULTS

Paired t-tests and percent change demonstrated significant decreases in compassion satisfaction (44.5 vs. 42.1, p = 0.04) and secondary traumatic stress score (18.5 vs. 13.3, p = 0.0001) and a significant increase in burnout score (17.6 vs. 20.5, p = 0.03) from baseline to follow up. Employee turnover slightly decreased from baseline to follow-up.

CONCLUSIONS

In this pilot study, hospice IDT members had low levels of well-being at baseline that worsened over 3-months indicating a higher potential risk for burnout. Moreover, given the COVID-19 pandemic, this may be an ominous sign of what lies ahead for hospice providers regarding turnover, leading to significant long-term staffing problems in the field. If these results hold true in a larger sample, it could necessitate developing and testing further strategies to ensure a healthy and stable workforce.

430 Evaluation of A Prioritisation Policy for HPB Resections in the COVID-19 Era

Aim

The COVID19 pandemic has caused oncological services worldwide to face unprecedented challenges resulting in treatment disruptions for cancer patients requiring surgery. Hepatopancreatico-biliary cancers are characterised by a low resectability rate and rapid progression. This study aims to assess the effectiveness of a prioritisation policy for this cohort of patients during the initial COVID19 outbreak.

Method

The prioritisation policy and triage system are described in detail. Patients undergoing surgery between April-July 2020 (COVID period) were compared to a control group from the preceding year. Statistical analysis was carried out to evaluate timeliness of treatment, peri-operative characteristics and short-outcomes.

Results

Patient selection was restructured to prioritise patients with performance status of &lt; 2 with presence of cancer complications, borderline resectable- or biologically aggressive disease. Where feasible, neoadjuvant therapy was advocated. An elective safe corridor pathway was established to reduce the risk of COVID19 infection. During the COVID19 and pre-COVID19 period, 94 and 115 patients underwent surgery, respectively. No patients contracted COVID19 post-operatively. There were less patients with ASA≥3 during the COVID19 period vs. pre-COVID19 (12.8% vs. 34.2%; p &lt; 0.001). Median time between referral and surgery was greater during the COVID19 compared to the pre-COVID19 period, at 64 days vs. 49 days, respectively (p = 0.023). Despite this difference no NHS waiting list breaches occurred. Incidence of postoperative complications were comparable between groups.

Conclusions

The outlined prioritisation policy for oncological hepatopancreatico-biliary resections was effective in providing safe surgery during the COVID-19 outbreak. Whether the observed delay in treatment will affect long-term outcomes remains to be seen

Tunable exciton-polaritons emerging from WS2 monolayer excitons in a photonic lattice at room temperature

Engineering non-linear hybrid light-matter states in tailored lattices is a central research strategy for the simulation of complex Hamiltonians. Excitons in atomically thin crystals are an ideal active medium for such purposes, since they couple strongly with light and bear the potential to harness giant non-linearities and interactions while presenting a simple sample-processing and room temperature operability. We demonstrate lattice polaritons, based on an open, high-quality optical cavity, with an imprinted photonic lattice strongly coupled to excitons in a WS2 monolayer. We experimentally observe the emergence of the canonical band-structure of particles in a one-dimensional lattice at room temperature, and demonstrate frequency reconfigurability over a spectral window exceeding 85 meV, as well as the systematic variation of the nearest-neighbour coupling, reflected by a tunability in the bandwidth of the p-band polaritons by 7 meV. The technology presented in this work is a critical demonstration towards reconfigurable photonic emulators operated with non-linear photonic fluids, offering a simple experimental implementation and working at ambient conditions.

Performance of image guided navigation in laparoscopic liver surgery - A systematic review

BACKGROUND

Compared to open surgery, minimally invasive liver resection has improved short term outcomes. It is however technically more challenging. Navigated image guidance systems (IGS) are being developed to overcome these challenges. The aim of this systematic review is to provide an overview of their current capabilities and limitations.

METHODS

Medline, Embase and Cochrane databases were searched using free text terms and corresponding controlled vocabulary. Titles and abstracts of retrieved articles were screened for inclusion criteria. Due to the heterogeneity of the retrieved data it was not possible to conduct a meta-analysis. Therefore results are presented in tabulated and narrative format.

RESULTS

Out of 2015 articles, 17 pre-clinical and 33 clinical papers met inclusion criteria. Data from 24 articles that reported on accuracy indicates that in recent years navigation accuracy has been in the range of 8-15 mm. Due to discrepancies in evaluation methods it is difficult to compare accuracy metrics between different systems. Surgeon feedback suggests that current state of the art IGS may be useful as a supplementary navigation tool, especially in small liver lesions that are difficult to locate. They are however not able to reliably localise all relevant anatomical structures. Only one article investigated IGS impact on clinical outcomes.

CONCLUSIONS

Further improvements in navigation accuracy are needed to enable reliable visualisation of tumour margins with the precision required for oncological resections. To enhance comparability between different IGS it is crucial to find a consensus on the assessment of navigation accuracy as a minimum reporting standard.

Adhesion-mediated mechanosignaling forces mitohormesis

Mitochondria control eukaryotic cell fate by producing the energy needed to support life and the signals required to execute programed cell death. The biochemical milieu is known to affect mitochondrial function and contribute to the dysfunctional mitochondrial phenotypes implicated in cancer and the morbidities of aging. However, the physical characteristics of the extracellular matrix are also altered in cancerous and aging tissues. Here, we demonstrate that cells sense the physical properties of the extracellular matrix and activate a mitochondrial stress response that adaptively tunes mitochondrial function via solute carrier family 9 member A1-dependent ion exchange and heat shock factor 1-dependent transcription. Overall, our data indicate that adhesion-mediated mechanosignaling may play an unappreciated role in the altered mitochondrial functions observed in aging and cancer.

The impact of photobiomodulation on the chondrogenic potential of adipose-derived stromal/stem cells

Due to their capacity to differentiate into the chondrogenic lineage, adipose-derived stromal/stem cells (ASC) are a promising source of therapeutically relevant cells for cartilage tissue regeneration. Their differentiation potential, however, varies between patients. In our study, we aim to stimulate ASC towards a more reliable chondrogenic phenotype using photobiomodulation (PBM). LED devices of either blue (475 nm), green (516 nm) or red (635 nm) light were used to treat human ASC from donors of varying chondrogenic potential. The treatment was applied either once during the 2D expansion phase or repeatedly during the 3D differentiation phase. Chondrogenic differentiation was assessed via pellet size, GAG/DNA content, histology and gene expression analysis. Reactions to PBM were found to be wavelength-dependent and more pronounced when the treatment was applied during expansion. Donors were assigned to responder categories according to their response to the treatment during expansion, whereby good responders were mainly donors with low intrinsic chondrogenic potential. Exposed to light, they revealed a particularly high relative increase in pellet size (more than twice the size of untreated controls after red light PBM), intense collagen type II immunostaining (low/absent in untreated controls) and activation of otherwise absent COL2A1 expression. Conversely, on a donor with high intrinsic chondrogenic potential, light had adverse effects. When applied with shorter wavelengths (blue, green), it led to reduced pellet size, GAG/DNA content and collagen type II immunostaining. However, when PBM was applied in 3D, the same donor was the only one to react with increased differentiation to all three wavelengths. We were able to demonstrate that PBM can be used to enhance or hamper chondrogenesis of ASC, and that success depends on treatment parameters and intrinsic cellular potential. The improvement of chondrogenesis in donors with low intrinsic potential highlights PBM as potent tool for cell-based cartilage regeneration. Its cost-effectiveness and ease of use make for an attractive treatment option to enhance the performance of ASC in cartilage tissue engineering.

Propagative Oscillations in Codirectional Polariton Waveguide Couplers

We report on novel exciton-polariton routing devices created to study and purposely guide light-matter particles in their condensate phase. In a codirectional coupling device, two waveguides are connected by a partially etched section that facilitates tunable coupling of the adjacent channels. This evanescent coupling of the two macroscopic wave functions in each waveguide reveals itself in real space oscillations of the condensate. This Josephson-like oscillation has only been observed in coupled polariton traps so far. Here, we report on a similar coupling behavior in a controllable, propagative waveguide-based design. By controlling the gap width, channel length, or propagation energy, the exit port of the polariton flow can be chosen. This codirectional polariton device is a passive and scalable coupler element that can serve in compact, next generation logic architectures.

Evaluation of the combination of endothelin receptor antagonists (ERA) and phosphodiesterase-5 inhibitors for the treatment of pulmonary arterial hypertension (PAH) in pathologic human pulmonary arteries in an ex-vivo organ bath model

PURPOSE

Medical combination therapy of pulmonary arterial hypertension (PAH) may alleviate the drawbacks of monotherapy by avoiding drug tolerance and by increasing effectiveness, as shown by the combination of ambrisentan and tadalafil (AMBITION trial). The present ex-vivo study evaluated the combination of the endothelin receptor antagonists (ERA) macitentan and bosentan with the phosphodiesterase-5 (PDE-5) inhibitor vardenafil in pulmonary arteries from patients suffering from terminal lung disease as a model of PAH.

METHODS

Segments of the pulmonary vessels were excised from resected lungs of patients requiring lung transplantation (LTX). Contraction of pulmonary arteries (PA) was elicited by consecutive dose-response curves of endothelin-1 (ET-1) followed by norepinephrine (NE) to allow inhibition by different pathways. Forces were measured isometrically in an organ bath in the presence and absence of ERA and PDE-5 inhibitors and their combination.

RESULTS

PA of 38 patients were examined between October 2016 and November 2019. Bosentan (1E-7 M) and macitentan (1E-8 M, 3E-8 M, 1E-7 M) inhibited ET-1 induced contractions, whereas vardenafil (1E-6 M, 3E-6 M, 1E-5 M) inhibited only the NE induced part of the contractions. Vardenafil enhanced bosentan-induced inhibition of vasoconstriction in a dose-dependent fashion. Combination effects exceeded single bosentan at 3E-6 M and 1E-5 M vardenafil, and they exceeded single vardenafil at the lower vardenafil concentrations. Macitentan showed a more pronounced inhibition than bosentan regardless of the lower concentrations. Accordingly, combination effects with vardenafil resembled those of macitentan alone.

CONCLUSIONS

Macitentan and bosentan were potent antagonists of vasoconstriction in PA of LTX patients. The benefit of drug combinations was demonstrated at selected concentrations only owing to a narrow therapeutic range of vardenafil in this ex-vivo model. These results suggest the utility of drug combinations other than the established pair of ambrisentan and tadalafil in PAH treatment but also make a case for a further assessment of vasodilator properties of drugs complementing ERA.

Observation of Intensity Squeezing in Resonance Fluorescence from a Solid-State Device

Intensity squeezing-i.e., photon number fluctuations below the shot-noise limit-is a fundamental aspect of quantum optics and has wide applications in quantum metrology. It was predicted in 1979 that intensity squeezing could be observed in resonance fluorescence from a two-level quantum system. However, its experimental observation in solid states was hindered by inefficiencies in generating, collecting, and detecting resonance fluorescence. Here, we report the intensity squeezing in a single-mode fiber-coupled resonance fluorescence single-photon source based on a quantum dot-micropillar system. We detect pulsed single-photon streams with 22.6% system efficiency, which show sub-shot-noise intensity fluctuation with an intensity squeezing of 0.59 dB. We estimate a corrected squeezing of 3.29 dB at the first lens. The observed intensity squeezing provides the last piece of the fundamental picture of resonance fluorescence, which can be used as a new standard for optical radiation and in scalable quantum metrology with indistinguishable single photons.

Prognostic relevance of the posterior resection margin for predicting disease free survival in ampullary adenocarcinoma

BACKGROUND

Pancreaticoduodenectomy is the only curative treatment option for patients with resectable ampullary adenocarcinoma (AA). Excellent disease free survival (DFS) can be achieved in patients with clear resection margins but it is poorly understood which patients are at increased risk of recurrence and hence would benefit from adjuvant chemotherapy. There is evolving evidence that the anatomical location of incomplete resection margins influences DFS in pancreatic adenocarcinoma. It is unknown if this also pertains to AA and therefore this study aimed to assess individual resection margin status and other predictors of DFS in AA.

MATERIAL & METHODS

Consecutive patients undergoing pancreaticoduodenectomy for AA at our institution from 1996 to 2017 were analysed. Pancreas neck, posterior and superior mesenteric vein margins were assessed individually. Cox proportional hazards modelling was used to identify predictors of 5-year DFS. Factors with p < 0.1 on univariate analysis were included for multivariate analysis.

RESULTS

Analysis of 104 patients revealed median OS and DFS of 56 and 34 months, respectively. Predictors associated with worse DFS on multivariate analysis were T3-stage (HR 3.6, p = 0.048), N1 (HR 2.9, p = 0.01) and N2 -stage (HR 3.6, p = 0.006), R1 status at the posterior margin (HR 3.0, p = 0.009) and a visible mass on CT (HR 2.0, p = 0.039).

CONCLUSION

Routine histopathological assessment of individual resection margins may aid in predicting recurrence of AA. Future studies to assess if routine mesopancreas excision during pancreaticoduodenectomy can reduce the incidence of R1 status at the posterior margin are warranted.

Demonstration of a polariton step potential by local variation of light-matter coupling in a van-der-Waals heterostructure

The large oscillator strength of excitons in transition metal dichalcogenide layers facilitates the formation of exciton-polariton resonances for monolayers and van-der-Waals heterostructures embedded in optical microcavities. Here, we show, that locally changing the number of layers in a WSe₂/hBN/WSe₂ van-der-Waals heterostructure embedded in a monolithic, high-quality-factor cavity gives rise to a local variation of the coupling strength. This effect yields a polaritonic stair case potential, which we demonstrate at room temperature. Our result paves the way towards engineering local polaritonic potentials at length scales down to atomically sharp interfaces, based on purely modifying its real part contribution via the coherent light-matter coupling strength g.

Room temperature organic exciton-polariton condensate in a lattice

Interacting Bosons in artificial lattices have emerged as a modern platform to explore collective manybody phenomena and exotic phases of matter as well as to enable advanced on-chip simulators. On chip, exciton–polaritons emerged as a promising system to implement and study bosonic non-linear systems in lattices, demanding cryogenic temperatures. We discuss an experiment conducted on a polaritonic lattice at ambient conditions: We utilize fluorescent proteins providing ultra-stable Frenkel excitons. Their soft nature allows for mechanically shaping them in the photonic lattice. We demonstrate controlled loading of the coherent condensate in distinct orbital lattice modes of different symmetries. Finally, we explore the self-localization of the condensate in a gap-state, driven by the interplay of effective interaction and negative effective mass in our lattice. We believe that this work establishes organic polaritons as a serious contender to the well-established GaAs platform for a wide range of applications relying on coherent Bosons in lattices.

Many studies of polariton condensates have been limited to low temperatures. Here the authors demonstrate ambient polariton condensation in lattices using organic traps that profit from the stability of organic excitons and the large Rabi splitting.

Interaction of Diet with the Metabolic Flux Signatures of the Unfolded Protein Response

Objectives

Endoplasmic reticulum (ER) stress is involved in the progression of several diseases, including diet and obesity-related conditions such as nonalcoholic fatty liver disease. Our goal was to understand the role of diet on the unfolded protein response (UPR), an important pathway in ER stress response, in efforts to elucidate the role of the UPR in the progression to non-alcoholic fatty liver disease.

Methods

We used stable isotope labeling with tandem mass spectrometric analysis to characterize proteome-wide synthesis rates and de novo lipogenesis rates in vivo in mouse liver to generate metabolic flux signatures of the unfolded protein response. We initiated the unfolded protein response through treatment with tunicamycin. Diets rich in either unsaturated, oleic, acids, or saturated, palmitic, acids were given to mice for five weeks to determine the effect of dietary fatty acids on this induced ER stress response.

Results

With induction of the unfolded protein response, we observed reduced protein synthesis across most ontologies, but increased synthesis of ER proteins and chaperones. We also found reduced de novo lipogenesis after 48 and 72 hours of induced ER stress. Reduction in food intake and significant weight loss also occurred after 48 and 72 hours. Electron microscopy revealed striking morphological differences in the ER and accumulation of lipid droplets with ER stress. Diets high in unsaturated fatty acids had a lesser impact on the progression of the unfolded protein response.

Conclusions

These data begin to characterize how the unfolded protein response progresses over time, and the metabolic changes that occur with ER stress. Diets rich in saturated or unsaturated fatty acids had different effects on the metabolic signatures of the UPR, suggesting the type dietary fatty acid is important in properly handling ER stress.

Funding Sources

NIH.

Trimethylamine-N-oxide is elevated in the acute phase after ischaemic stroke and decreases within the first days

BACKGROUND AND PURPOSE

Trimethylamine-N-oxide (TMAO) is a biomarker of the gut microbiome and correlates with the risk of cardiovascular diseases. However, conflicting data exist on the specific role of TMAO in ischaemic stroke patients. We aimed to analyze the time course of TMAO levels in stroke patients compared with controls.

METHODS

In this prospective, case-control study, patients suffering from ischaemic stroke (onset <24 h) and control patients with less than two cardiovascular risk factors were enrolled. Plasma TMAO levels were analyzed on admission, after 48 h and after 3 months. The primary endpoint was the difference in TMAO levels on admission between stroke patients and controls.

RESULTS

A total of 196 patients with ischaemic stroke and 100 controls were included between February 2018 and April 2019. Plasma TMAO levels on admission were significantly higher in stroke patients than in controls [median value 4.09 (2.87-6.49) vs. 3.16 (2.08-5.16) µmol/L, P = 0.001]. There was a significant decrease in TMAO levels in stroke patients after 48 h [median at 48 h, 3.49 (2.30-5.39) µmol/L, P = 0.027]. TMAO levels increased again 3 months after stroke [median 4.23 (2.92-8.13) µmol/L, P = 0.047]. In controls, TMAO levels did not change between admission and after 48 h [median at 48 h, 3.14 (1.63-4.61) µmol/L, P = 0.11]. An inverse correlation between TMAO values and kidney function was found (Spearman rho -0.334, P < 0.001).

CONCLUSIONS

Our study emphasizes the importance of the time course of TMAO levels after ischaemic stroke. Future studies should define the time point of TMAO analysis, preferably in the acute phase (<24 h).

Risk factors associated with progressive lacunar strokes and benefit from dual antiplatelet therapy

BACKGROUND AND PURPOSE

Early neurological deterioration (END) occurs in 20%-30% of patients with lacunar stroke and challenges their clinical management. This retrospective cohort study analyzed clinical and neuroimaging risk factors predicting the occurrence of END, the functional outcome after END and potential benefit from dual antiplatelet therapy (DAPT) in patients with lacunar strokes.

METHODS

Factors associated with END and benefit from DAPT were retrospectively analyzed in 308 patients with lacunar stroke symptoms and detected lacunar infarction by magnetic resonance imaging. END was defined by deterioration of ≥3 total National Institutes of Health Stroke Scale (NIHSS) points, ≥2 NIHSS points for limb paresis or documented deterioration within 5 days after admission. Patients were treated with DAPT according to in-house standards. The primary efficacy end-point for functional outcome was fulfilled if NIHSS at discharge improved after END at least to the score at admission.

RESULTS

Male gender [odds ratio (OR) 2.08; 95% confidence interval (CI) 1.09-4.00], higher age (OR = 1.65 per 10 years; 95% CI 1.18-2.31), motor paresis (OR = 18.89, 95% CI 4.66-76.57) and infarction of the internal capsule or basal ganglia (OR = 3.58, 95% CI 1.26-10.14) were associated with an increased risk for END. A larger diameter of infarction (OR = 0.85, 95% CI 0.76-0.95), more microangiopathic lesions (OR = 0.75, 95% CI 0.57-0.99) and pontine localization (OR = 0.29, 95% CI 0.12-0.65) were factors associated with unfavorable functional outcome after END occurred. Localization in the internal capsule or basal ganglia was identified as a significant predictive factor for a benefit from DAPT after END.

CONCLUSIONS

Identified clinical and neuroimaging factors predicting END occurrence, functional outcome after END and potential benefit from DAPT might improve the clinical management of patients with lacunar strokes.

Comparison of manual and semi-automatic registration in augmented reality image-guided liver surgery: a clinical feasibility study

BACKGROUND

The laparoscopic approach to liver resection may reduce morbidity and hospital stay. However, uptake has been slow due to concerns about patient safety and oncological radicality. Image guidance systems may improve patient safety by enabling 3D visualisation of critical intra- and extrahepatic structures. Current systems suffer from non-intuitive visualisation and a complicated setup process. A novel image guidance system (SmartLiver), offering augmented reality visualisation and semi-automatic registration has been developed to address these issues. A clinical feasibility study evaluated the performance and usability of SmartLiver with either manual or semi-automatic registration.

METHODS

Intraoperative image guidance data were recorded and analysed in patients undergoing laparoscopic liver resection or cancer staging. Stereoscopic surface reconstruction and iterative closest point matching facilitated semi-automatic registration. The primary endpoint was defined as successful registration as determined by the operating surgeon. Secondary endpoints were system usability as assessed by a surgeon questionnaire and comparison of manual vs. semi-automatic registration accuracy. Since SmartLiver is still in development no attempt was made to evaluate its impact on perioperative outcomes.

RESULTS

The primary endpoint was achieved in 16 out of 18 patients. Initially semi-automatic registration failed because the IGS could not distinguish the liver surface from surrounding structures. Implementation of a deep learning algorithm enabled the IGS to overcome this issue and facilitate semi-automatic registration. Mean registration accuracy was 10.9 ± 4.2 mm (manual) vs. 13.9 ± 4.4 mm (semi-automatic) (Mean difference - 3 mm; p = 0.158). Surgeon feedback was positive about IGS handling and improved intraoperative orientation but also highlighted the need for a simpler setup process and better integration with laparoscopic ultrasound.

CONCLUSION

The technical feasibility of using SmartLiver intraoperatively has been demonstrated. With further improvements semi-automatic registration may enhance user friendliness and workflow of SmartLiver. Manual and semi-automatic registration accuracy were comparable but evaluation on a larger patient cohort is required to confirm these findings.