The line bisection bias as a deficit of proportional reasoning - evidence from number line estimation in neglect

This study aimed to investigate whether neurological patients presenting with a bias in line bisection show specific problems in bisecting a line into two equal parts or their line bisection bias rather reflects a special case of a deficit in proportional reasoning more generally. In the latter case, the bias should also be observed for segmentations into thirds or quarters. To address this question, six neglect patients with a line bisection bias were administered additional tasks involving horizontal lines (e.g., segmentation into thirds and quarters, number line estimation, etc.). Their performance was compared to five neglect patients without a line bisection bias, 10 patients with right hemispheric lesions without neglect, and 32 healthy controls. Most interestingly, results indicated that neglect patients with a line bisection bias also overestimated segments on the left of the line (e.g., one third, one quarter) when dissecting lines into parts smaller than halves. In contrast, such segmentation biases were more nuanced when the required line segmentation was framed as a number line estimation task with either fractions or whole numbers. Taken together, this suggests a generalization of line bisection bias towards a segmentation or proportional processing bias, which is congruent with attentional weighting accounts of line bisection/neglect. As such, patients with a line bisection bias do not seem to have specific problems bisecting a line, but seem to suffer from a more general deficit processing proportions.

Tunable Organic Active Neural Probe Enabling Near-Sensor Signal Processing

Neural recording systems have significantly progressed to provide an advanced understanding and treatment for neurological diseases. Flexible transistor-based active neural probes exhibit great potential in electrophysiology applications due to their intrinsic amplification capability and tissue-compliant nature. However, most current active neural probes exhibit bulky back-end connectivity since the output is current, and the development of an integrated circuit for voltage output is crucial for near-sensor signal processing at the abiotic/biotic interface. Here, inkjet-printed organic voltage amplifiers are presented by monolithically integrating organic electrochemical transistors and thin-film polymer resistors on a single, highly flexible substrate for in vivo brain activity recording. Additive inkjet printing enables the seamless integration of multiple active and passive components on the somatosensory cortex, leading to significant noise reduction over the externally connected typical configuration. It also facilitates fine-tuning of the voltage amplification and frequency properties. The organic voltage amplifiers are validated as electrocorticography devices in a rat in vivo model, showing their ability to record local field potentials in an experimental model of spontaneous and epileptiform activity. These results bring organic active neural probes to the forefront in applications where efficient sensory data processing is performed at sensor endpoints.

3D Inkjet-Bioprinted Lung-on-a-Chip

There is an urgent need for physiologically relevant and customizable biochip models of human lung tissue to provide a niche for lung disease modeling and drug efficacy. Although various lung-on-a-chips have been developed, the conventional fabrication method has been limited in reconstituting a very thin and multilayered architecture and spatial arrangements of multiple cell types in a microfluidic device. To overcome these limitations, we developed a physiologically relevant human alveolar lung-on-a-chip model, effectively integrated with an inkjet-printed, micron-thick, and three-layered tissue. After bioprinting lung tissues inside four culture inserts layer-by-layer, the inserts are implanted into a biochip that supplies a flow of culture medium. This modular implantation procedure enables the formation of a lung-on-a-chip to facilitate the culture of 3D-structured inkjet-bioprinted lung models under perfusion at the air-liquid interface. The bioprinted models cultured on the chip maintained their structure with three layers of tens of micrometers and achieved a tight junction in the epithelial layer, the critical properties of an alveolar barrier. The upregulation of genes involved in the essential functions of alveoli was also confirmed in our model. Our culture insert-mountable organ-on-a-chip is a versatile platform that can be applied to various organ models by implanting and replacing culture inserts. It is amenable to mass production and the development of customized models through the convergence with bioprinting technology.

Sonochemical Degradation of Gelatin Methacryloyl to Control Viscoelasticity for Inkjet Bioprinting

Inkjet printing enables the mimicry of the microenvironment of natural complex tissues by patterning cells and hydrogels at a high resolution. However, the polymer content of an inkjet-printable bioink is limited as it leads to strong viscoelasticity in the inkjet nozzle. Here it is demonstrated that sonochemical treatment controls the viscoelasticity of a gelatin methacryloyl (GelMA) based bioink by shortening the length of polymer chains without causing chemical destruction of the methacryloyl groups. The rheological properties of treated GelMA inks are evaluated by a piezo-axial vibrator over a wide range of frequencies between 10 and 10 000 Hz. This approach enables to effectively increase the maximum printable polymer concentration from 3% to 10%. Then it is studied how the sonochemical treatment effectively controls the microstructure and mechanical properties of GelMA hydrogel constructs after crosslinking while maintaining its fluid properties within the printable range. The control of mechanical properties of GelMA hydrogels can lead fibroblasts more spreading on the hydrogels. A 3D cell-laden multilayered hydrogel constructs containing layers with different physical properties is fabrictated by using high-resolution inkjet printing. The sonochemical treatment delivers a new path to inkjet bioprinting to build microarchitectures with various physical properties by expanding the range of applicable bioinks.

Disconnection in a left-hemispheric temporo-parietal network impairs multiplication fact retrieval

Arithmetic fact retrieval has been suggested to recruit a left-lateralized network comprising perisylvian language areas, parietal areas such as the angular gyrus (AG), and non-neocortical structures such as the hippocampus. However, the underlying white matter connectivity of these areas has not been evaluated systematically so far. Using simple multiplication problems, we evaluated how disconnections in parietal brain areas affected arithmetic fact retrieval following stroke. We derived disconnectivity measures by jointly considering data from n = 73 patients with acute unilateral lesions in either hemisphere and a white-matter tractography atlas (HCP-842) using the Lesion Quantification Toolbox (LQT). Whole-brain voxel-based analysis indicated a left-hemispheric cluster of white matter fibers connecting the AG and superior temporal areas to be associated with a fact retrieval deficit. Subsequent analyses of direct gray-to-gray matter disconnections revealed that disconnections of additional left-hemispheric areas (e.g., between the superior temporal gyrus and parietal areas) were significantly associated with the observed fact retrieval deficit. Results imply that disconnections of parietal areas (i.e., the AG) with language-related areas (i.e., superior and middle temporal gyri) seem specifically detrimental to arithmetic fact retrieval. This suggests that arithmetic fact retrieval recruits a widespread left-hemispheric network and emphasizes the relevance of white matter connectivity for number processing.

Cationic Iridium(III) Complexes with Benzothiophene-Quinoline Ligands for Deep-Red Light-Emitting Electrochemical Cells

Three new cationic cyclometalated iridium(III) complexes equipped with differently substituted benzo[b]thiophen-2-ylquinoline cyclometalating ligands and with a sterically demanding tert-butyl-substituted 2,2'-bipyridine ancillary ligand were synthesized and structurally characterized by NMR and X-ray diffraction techniques. To tune the electronic properties of such complexes, the quinoline moiety of the cyclometalating ligands was kept pristine or equipped with electron-withdrawing phenyl and -CF₃ substituents, leading to complexes 1, 2, and 3, respectively. A complete electrochemical and photophysical investigation, supported by density functional theory calculations, permits a deep understanding of their electronic properties. The emission of all complexes arises from ligand-centered triplet states in the spectral range between 625 and 950 nm, with excited-state lifetimes between 2.10 and 6.32 μs at 298 K. The unsubstituted complex (1) exhibits the most blue-shifted emission in polymeric matrix at 298 K (λ_max = 667 nm, photoluminescence quantum yield (PLQY) = 0.25 and τ = 5.32 μs). The phenyl-substituted complex (2) displays the highest photoluminescent quantum yields (up to 0.30 in polymeric matrix), while the CF₃-substituted counterpart (3) shows the most red-shifted emission, peaking at approx. 720 nm, but with lower quantum yields (e.g., 0.10 in polymeric matrix at 298 K). Complexes 1 and 2 were tested in single-layer nondoped light-emitting electrochemical cells (LEECs), using a nozzle-printing technique; both devices display deep-red electroluminescence with an external quantum efficiency close to 20%.

Transfer-Tattoo-Like Cell-Sheet Delivery Induced by Interfacial Cell Migration

A direct transfer of a cell sheet from a culture surface to a target tissue is introduced. Commercially available, flexible parylene is used as the culture surface, and it is proposed that the UV-treated parylene offers adequate and intermediate levels of cell adhesiveness for both the stable cell attachment during culture and for the efficient cell transfer to a target surface. The versatility of this cell-transfer process is demonstrated with various cell types, including MRC-5, HDFn, HULEC-5a, MC3T3-E1, A549, C2C12 cells, and MDCK-II cells. The novel cell-sheet engineering is based on a mechanism of interfacial cell migration between two surfaces with different adhesion preferences. Monitoring of cytoskeletal dynamics and drug treatments during the cell-transfer process reveals that the interfacial cell migration occurs by utilizing the existing transmembrane proteins on the cell surface to bind to the targeted surface. The re-establishment and reversal of cell polarity after the transfer process are also identified. Its unique capabilities of 3D multilayer stacking, freeform design, and curved surface application are demonstrated. Finally, the therapeutic potential of the cell-sheet delivery system is demonstrated by applying it to cutaneous wound healing and skin-tissue regeneration in mice models.

3D pulmonary fibrosis model for anti-fibrotic drug discovery by inkjet-bioprinting

Pulmonary fibrosis (PF) is known as a chronic and irreversible disease characterized by excessive extracellular matrix accumulation and lung architecture changes. Large efforts have been made to develop prospective treatments and study the etiology of pulmonary fibrotic diseases utilizing animal models and spherical organoids. As part of these efforts, we created an all-inkjet-printed three-dimensional (3D) alveolar barrier model that can be used for anti-fibrotic drug discovery. Then, we developed a PF model by treating the 3D alveolar barrier with pro-fibrotic cytokine and confirmed that it is suitable for the fibrosis model by observing changes in structural deposition, pulmonary function, epithelial-mesenchymal transition, and fibrosis markers. The model was tested with two approved anti-fibrotic drugs, and we could observe that the symptoms in the disease model were alleviated. Consequently, structural abnormalities and changes in mRNA expression were found in the induced fibrosis model, which were shown to be recovered in all drug treatment groups. The all-inkjet-printed alveolar barrier model was reproducible for disease onset and therapeutic effects in the human body. This finding emphasized that thein vitroartificial tissue with faithfully implemented 3D microstructures using bioprinting technology may be employed as a novel testing platform and disease model to evaluate potential drug efficacy.

Membranous septum length as predictor for permanent pacemaker implantation after TAVI

Background

High-degree atrioventricular (AV) block and permanent pacemaker (PPM) implantation represent major complications after transcatheter aortic valve implantation (TAVI). Extension of indication for TAVI towards subjects with lower surgical risk requires to reduce the likelihood for the requirement of permanent pacemaker (PPM) implantation. Data on the role of membranous septum length as potential predictor for AV block after TAVI are scarce.

Purpose

We examined the role of membranous septum length as potential predictor for AV block and the need for PPM implantation in a large cohort of consecutive subjects after TAVI.

Methods

In a cohort of 1365 patients without prior permanent pacemaker who underwent transfemoral TAVI, clinical and procedural characteristics were assessed systematically. Based on cardiac computed tomography performed prior to TAVI, membranous septum length was measured orthogonal to the anulus plane (see figure).

Results

Median age of subjects was 81 (IQR 7) years, 50% were male. Logistic euroSCORE was 12.8 (IQR 15.7), STS score 3 (2.7). 9,8% of subjects had a pre-interventional complete right bundle branch block (RBBB). 71% of patients received a balloon-expandable, 29% a self-expandable valve. In n=153 patients (11.2%), PPM implantation was necessary due to high-degree AV block. Median membranous septum length was 2.9 mm (IQR 2.5mm) in subjects who received a PPM versus 4.3 mm (IQR 3.2 mm) in subjects who did not need a PPM (p=0.061). In univariate regression analysis, pre-interventional complete RBBB (p<0.001, OR 7.8), implantation of a self-expandable prosthesis (p=0002, OR 1.7) and membranous septum length (p=0.027, OR 0.9 per 1 mm) were identified as significant predictors for PPM implantation. In multivariate regression analysis, all parameters remained significant, including membranous septum length (p=0.009, OR 0.9 per 1 mm).

Conclusion

In a large cohort of consecutive patients, we were able to confirm the significant independent predictive value of membranous septum length, in addition to pre-interventional complete RBBB or implantation of a self-expandable prosthesis, regarding the occurrence of post-procedural AV block with the need for PPM implantation. The results may contribute to improved risk stratification for potential PPM implantation after TAVI.

Funding Acknowledgement

Type of funding sources: None.

Use of a 3D inkjet-printed model to access dust particle toxicology in the human alveolar barrier

Fine dust particles in the air travel into our body via the airway tract and cause severe respiratory diseases. Thus, the analysis of the effects of dust particles on the respiratory system has been receiving significant research interest. However, most studies on the toxicity of dust particles involve two-dimensional (2D) cell cultures, animal models, and epidemiology. Here, we inkjet-printed an three-dimensional (3D) alveolar barrier model to study how dust particles cause respiratory diseases. The three-layered in vitro model was exposed to A2 fine test dust with varying concentrations and exposure durations. The results highlighted the destruction of the tissue architecture along with apoptosis in the bioprinted alveolar barrier. The damage at the cellular level induced an increase in the amount of pro-inflammatory cytokines secreted, followed by triggering of the signal transduction pathway and activation of transcription factors. As a consequence of the release of cytokines, the extracellular matrix was degraded, which led to the collapse of the cell structure, loss of cell polarity, and a decrease in the barrier tightness. Further, the pulmonary surfactant protein-related genes in the dust-treated alveolar tissue were investigated to evaluate the possible role of dust particles in pulmonary surfactant dysfunction. This study demonstrated the use of 3D-printed tissue model to evaluate the physiological impact of fine dust particles on cytotoxicity, alveolar barrier rigidity, and surfactant secretion of an alveolar barrier. This article is protected by copyright. All rights reserved.

Multi-disciplinary assessment of the entrustable professional activities of surgery residents

Purpose

Medicine is practiced in a collaborative and interdisciplinary manner. However, medical training and assessment remain largely isolated in traditional departmental silos. Two Entrustable Professional Activities (EPAs) developed by the American Board of Surgery are multidisciplinary in nature and offer a unique opportunity to study interdisciplinary assessment.

Methods

EPA microassessments were collected from Surgery and Emergency Medicine (EM) faculty between July 2018 and May 2020. Differences in feedback provided by faculty were assessed using natural language processing (NLP) techniques, (1) automated algorithms; and (2) topic modeling. Summative content analysis was used to identify themes in text feedback. We developed automated coding algorithms for these themes using regular expressions. Topic modeling was performed using latent Dirichlet allocation.

Results

549 assessments were collected for two EPAs: 198 for GS Consultation and 351 for Trauma. 27 EM and 27 Surgery faculty provided assessments for 71 residents. EM faculty were significantly more likely than Surgery faculty to submit feedback coded as Communication, Demeanor, and Timeliness, (all chi-square test p-values < 0.01). No significant differences were found for Clinical Performance, Skill Level, or Areas for Improvement. Similarly, topic modeling indicated that assessments submitted by EM faculty focused on communication, timeliness, and interpersonal skills, while those submitted by Surgery faculty focused on the residents' abilities to effectively gather information and correctly diagnose the underlying pathology.

Conclusions

Feedback from EM and Surgery faculty differed significantly based on NLP analyses. EPA assessments should stem from multiple sources to avoid assessment gaps and represent a more holistic picture of performance.

Printable inks and deformable electronic array devices

Deformable printed electronic array devices are expected to revolutionize next-generation electronics. However, although remarkable technological advances in printable inks and deformable electronic array devices have recently been achieved, technical challenges remain to commercialize these technologies. In this review article a brief introduction to printing methods highlighting significant research studies on ink formation for conductors, semiconductors, and insulators is provided, and the structural design and successful printing strategies of deformable electronic array devices are described. Successful device demonstrations are presented in the applications of passive- and active-matrix array devices. Finally, perspectives and technological challenges to be achieved are pointed out to print practically available deformable devices.

Diagnostic Accuracy of High-Resolution 3D T2-SPACE in Detecting Cerebral Venous Sinus Thrombosis

BACKGROUND AND PURPOSE

Assessment of cerebral venous sinus thrombosis on MR imaging can be challenging. The aim of this study was to evaluate the diagnostic accuracy of high-resolution 3D T2 sampling perfection with application-optimized contrasts by using different flip angle evolution (SPACE) in patients with cerebral venous sinus thrombosis and to compare its performance with contrast-enhanced 3D T1-MPRAGE.

MATERIALS AND METHODS

We performed a blinded retrospective analysis of T2-SPACE and contrast-enhanced MPRAGE sequences from patients with cerebral venous sinus thrombosis and a control group. The results were compared with a reference standard, which was based on all available sequences and clinical history. Subanalyses were performed according to the venous segment involved and the clinical stage of the thrombus.

RESULTS

Sixty-three MR imaging examinations from 35 patients with cerebral venous sinus thrombosis and 51 examinations from 40 control subjects were included. The accuracy, sensitivity, and specificity calculated from the initial MR imaging examination for each patient were 100% each for T2-SPACE and 95%, 91%, and 98%, respectively, for contrast-enhanced MPRAGE. The interrater reliability was high for both sequences. In the subanalysis, the accuracy for each venous segment involved and if subdivided according to the clinical stage of thrombus was ≥95% and ≥85% for T2-SPACE and contrast-enhanced MPRAGE, respectively.

CONCLUSIONS

Both T2-SPACE and contrast-enhanced MPRAGE offer high accuracy for the detection and exclusion of cerebral venous sinus thrombosis; however, T2-SPACE showed a better overall performance and thus could be a useful tool if included in a multiparametric MR imaging protocol for the diagnosis of cerebral venous sinus thrombosis, especially in scenarios where gadolinium administration is contraindicated.

Spatiotemporal Measurement of Arterial Pulse Waves Enabled by Wearable Active-Matrix Pressure Sensor Arrays

Wearable pressure sensors have demonstrated great potential in detecting pulse pressure waves on the skin for the noninvasive and continuous diagnosis of cardiac conditions. However, difficulties lie in positioning conventional single-point sensors on an invisible arterial line, thereby preventing the detection of adequate signal amplitude for accurate pulse wave analysis. Herein, we introduce the spatiotemporal measurements of arterial pulse waves using wearable active-matrix pressure sensors to obtain optimal pulse waveforms. We fabricate thin-film transistor (TFT) arrays with high yield and uniformity using inkjet printing where array sizes can be customizable and integrate them with highly sensitive piezoresistive sheets. We maximize the pressure sensitivity (16.8 kPa^-1) and achieve low power consumption (10¹ nW) simultaneously by strategically modulating the TFT operation voltage. The sensor array creates a spatiotemporal pulse wave map on the wrist. The map presents the positional dependence of pulse amplitudes, which allows the positioning of the arterial line to accurately extract the augmentation index, a parameter for assessing arterial stiffness. The device overcomes the positional inaccuracy of conventional single-point sensors, and therefore, it can be used for medical applications such as arterial catheter injection or the diagnosis of cardiovascular disease in daily life.

Effect of empagliflozin on ketone bodies in patients with stable chronic heart failure

Background

Recent studies indicated that sodium glucose cotransporter (SGLT)2 inhibition increases levels of ketone bodies in the blood in patients with type 1 and 2 diabetes. Other studies suggested that in patients with chronic heart failure (CHF), increased myocardial oxygen demand can be provided by ketone bodies as a fuel substrate. Experimental studies reported that ketone bodies, specifically beta-hydroxybutyrate (β-OHB) may increase blood pressure (BP) by impairing endothelium-dependant relaxation, thereby leading to increased vascular stiffness. In our study we assessed whether the SGLT 2 inhibition with empagliflozin increases ketone bodies in patients with stable CHF and whether such an increase impairs BP and vascular function.

Methods

In a prospective, double blind, placebo controlled, parallel-group single centre study 75 patients with CHF (left ventricular ejection fraction 39.0 ± 8.2%) were randomised (2:1) to the SGLT-2 inhibitor empagliflozin 10 mg orally once daily or to placebo, 72 patients completed the study. After a run-in phase we evaluated at baseline BP by 24 h ambulatory blood pressure (ABP) monitoring, vascular stiffness parameters by the SphygmoCor system (AtCor Medical, Sydney, NSW, Australia) and fasting metabolic parameters, including β-OHB by an enzymatic assay (Beckman Coulter DxC 700 AU). The same measurements were repeated 12 weeks after treatment. In 19 of the 72 patients serum levels of β-OHB were beneath the lower border of our assay (< 0.05 mmol/l) therefore being excluded from the subsequent analysis.

Results

In patients with stable CHF, treatment with empagliflozin (n = 36) was followed by an increase of β-OHB by 33.39% (p = 0.017), reduction in 24 h systolic (p = 0.038) and diastolic (p = 0.085) ABP, weight loss (p = 0.003) and decrease of central systolic BP (p = 0.008) and central pulse pressure (p = 0.008). The increase in β-OHB was related to an attenuated decrease of empagliflozin-induced 24 h systolic (r = 0.321, p = 0.069) and diastolic (r = 0.516, p = 0.002) ABP and less reduction of central systolic BP (r = 0.470, p = 0.009) and central pulse pressure (r = 0.391, p = 0.033). No significant changes were seen in any of these parameters after 12 weeks of treatment in the placebo group (n = 17).

Conclusion

In patients with stable CHF ketone bodies as assessed by β-OHB increased after treatment with empagliflozin. This increase led to an attenuation of the beneficial effects of empagliflozin on BP and vascular parameters.

Trial registration The study was registered at http://www.clinicaltrials.gov (NCT03128528).

Reduced tissue sodium content is related to improvement of vascular function in patients with chronic heart failure treated with the SGLT2 inhibitor empagliflozin

Background

Large randomized controlled trials have demonstrated that SGLT2 inhibitors produce cardiovascular benefits beyond their metabolic effects. One of the assumed underlying mechanisms is the reduction of the left ventricular afterload. Factors aggravating the afterload are impaired vascular function (ventricular-arterial coupling) as well as high tissue sodium content, which exerts enhanced hypertrophic stimuli and exaggerated response to vasoconstrictors.

Purpose

We hypothesized that the SGLT2 inhibitor empagliflozin leads to afterload reduction in patients with chronic heart failure (CHF) by reducing tissue sodium content and improving vascular function and that these changes are related to each other.

Methods

In a randomized (2:1), investigator initiated, double-blind, placebo controlled, parallel-group, prospective clinical study, patients with CHF NYHA II-III and an ejection fraction of 49% or less were randomized to empagliflozin 10mg once daily or placebo. In each patient, we assessed vascular parameters under resting conditions (Sphygmocor) and 24-hour daily life conditions (Mobilograph), including central systolic pressure (cSBP) and central pulse pressure (cPP) among others. In parallel, we measured tissue (skin and muscle) sodium content of the lower leg by Sodium-MRI, at baseline and after 1 month of therapy.

Results

A total of 74 patients (men: n=62), aged 66±9 years, with a mean ejection fraction of 39±9% were included. Only 24% of the patients had type 2 diabetes. After 1 month treatment with empagliflozin, a decrease of skin sodium content was observed (22.8±6.1 vs. 21.6±6.0 mmol/l, p=0.039), while there was no significant change in muscle sodium and muscle water content. A decrease of cSBP (117.1±14.5 vs. 110.7±11.3 mmHg, p&lt;0.001) and cPP (41.4±8.8 vs. 38.4±8.5 mmHg, p=0.004) under resting conditions was observed after 1 month treatment with empagliflozin, while changes in the placebo group were not significant for cSBP (117.0±18.1 vs. 116.3±15.0 mmHg, p=0.759) and cPP (40.6±9.1 vs. 39.4±8.6 mmHg, p=0.422). Similarly, there was a decrease of cSBP and cPP in patients with empagliflozin treatment under ambulatory conditions, but not in the placebo group. In the whole group, we observed a significant correlation between change in skin sodium content and change in vascular parameters such as cSBP (r=0.364, p=0.004) and cPP (r=0.250, p=0.054) after 1 month of treatment with empagliflozin or placebo.

Conclusion(s)

Significant changes in skin sodium content induced by empagliflozin and a significant correlation between changes in skin sodium content and vascular function suggest that a reduction of tissue sodium content may be one of the mechanisms underlying the beneficial effects of SGLT2 inhibitors in heart failure.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Boehringer Ingelheim International GmbH.

High-degree atrioventricular block after valve-in-valve transcatheter aortic valve implantation: incidence and predictors

Background

High-degree atrioventricular (AV) block and permanent pacemaker (PPM) implantation represent major complications after transcatheter aortic valve implantation (TAVI). Data on the incidence of AV block for patients undergoing valve-in-valve (ViV) TAVI are scarce. We examined the incidence and predictors of periinterventional AV conduction disturbances in a cohort of subjects undergoing ViV TAVI compared to subjects undergoing TAVI of native aortic valves.

Methods

In 50 consecutive patients who underwent ViV TAVI, clinical characteristics, incidence and predictors for AV conduction disturbances as well as intrahospital outcome were assessed. Applying a matched pair approach for age, gender, type and size of transcatheter valve, these subjects were compared to 50 patients undergoing TAVI of native tricuspid aortic valves.

Results

Mean age in both groups was 80±6 years and 50% of subjects were male. In the ViV group, 22 patients (44%) had a stented bioprosthesis, 10 patients (20%) a stentless bioprosthesis and 18 patients (36%) a previous TAVI prosthesis (balloon-expandable: n=15, self-expandable n=3). The majority of subjects (92% in each group) were treated using balloon-expandable valves (ViV group: Sapien XT, n=20 or Sapien 3, n=26, control group: Sapien XT, n=19 or Sapien 3, n=27).

Periinterventional, non-reversible 3rd degree AV-block occurred in 6 patients within each group (12%), and all of the affected patients underwent PPM implantation. Among the 32 patients who underwent ViV-TAVI of a surgically placed bioprosthesis, only 2 (6%) developed a high-degree AV block (1/22 with a stented bioprosthesis and 1/10 with a stentless bioprosthesis). In contrast, high-degree AV block occurred in 4/18 patients (22%) who underwent ViV TAVI of a prior TAVI prosthesis. There was a significant difference in the occurrence of total high-degree AV blocks requiring postinterventional PPM implantation (p=0.033) between subjects who received TAVI of stented bioprostheses and those who received re-TAVI.

In logistic regression analysis, pre-existing RBBB represented a significant predictor for periinterventional 3rd degree AV block across the whole cohort (p=0.001, Exp(B)=10.667), both in ViV subjects (p=0.016, Exp(B)=12.0) and in the control group (p=0.018, Exp(B)=10.0).

Conclusion

Periinterventional AV block occurs infrequently in subjects undergoing ViV TAVI for treatment of degenerated surgical bioprostheses. However, patients undergoing ViV TAVI for degenerated transcatheter prostheses as well as subjects with pre-existing RBBB are at substantial risk for the occurence of AV block and require close peri-interventional monitoring.

Funding Acknowledgement

Type of funding sources: None.

Layout-to-Bitmap Conversion and Design Rules for Inkjet-Printed Large-Scale Integrated Circuits

Digital inkjet printing (IJP) can greatly reduce the manufacturing cost and waste of flexible large-area electronics by adding micro-fine patterns onto plastic foils. Advanced system design using IJP has been limited by the lack of an electronic design automation (EDA) approach. An EDA approach based on a vector-based layout drawing requires parameterized IJP design rules. This study proposes a layout-to-bitmap (L2B) conversion procedure and line-based design rules that leverage the existing circuit layout EDA tools for advanced IJP designs. The L2B conversion is accomplished by optimizing the parameters of the horizontal and vertical lines by varying the drop spacings and platen temperatures. Next, the line-based layouts are converted to bitmap files which are used as IJP input data for printing multiple metal layers. This study systematically investigated the development of an IJP process employing Ag nanoparticles. The physical characteristics of the proposed process were evaluated based on theories concerning inkjet-printed bead formation. The design rules for fabricating printed thin-film transistor (TFT) circuits were documented. Documentation is the first step in creating an IJP process design kit for advanced electronics design. Using the optimized L2B conversion procedure and the design rules, a 10 × 10 array of printed organic TFTs was fabricated to demonstrate the reliability of the developed process. Additionally, the fabricated printed organic TFTs indicated that the proposed process could be extended to large-scale system designs.

P04.22 Tumor treating fields in high-grade glioma patients: A retrospective single-center study

BACKGROUND

Tumor-treating fields (TTFields) are a modern anti-mitotic, non-invasive therapy for the treatment of patients with recurrent and newly diagnosed glioblastoma multiforme (GBM). In Europe, Optune® recieved in 2015 the CE certification. TTFields are a low-intensity (1–3 V/cm) approved therapeutic modality using a non-invasive application of intermediate frequency (200 kHz) alternating electric fields through four transducer arrays directly applied to the skin. The EF-14 study has shown that the addition of TTFields to temozolomide chemotherapy in patients with newly diagnosed GBM significantly improved overall survival (OS) and progression-free survival (PFS) without additional adverse events, apart from mild to moderate skin irritations (Stupp et al., JAMA 2017).

MATERIAL

We retrospectively analyzed data from TTFields-treated patients (2015–2020) that were treated at our department. Patient characteristics such as MGMT promoter methylation status, age, and diagnosis, as well as treatment duration and TTFields therapy usage, were evaluated for this study.

RESULTS

29 patients were treated with TTFields therapy between 2015 and 2020 at our hospital. Most patients received TTFields as primary treatment together with temozolomide maintenance therapy. In detail, 48% of patients were diagnosed with newly diagnosed GBM, 41% received TTFields therapy after tumor recurrence and 10% were diagnosed with other high-grade gliomas. In summary, patients could integrate TTFields therapy into their daily life and showed high adherence to the therapy.Particularly, one of our patients (with MGMT-promoter methylation positive) receives TTFields therapy now for almost 1229 days (approx. 41 months) and is still on therapy. Additionally, this patient shows a high usage rate of 86% indicating well integration of the therapy into daily life.

CONCLUSION

Taken together, our data provided the outcomes of using TTFields together with chemotherapy in the treatment of recurrent and newly diagnosed GBM in our department. Therapy with TTFields has been showing to provide significant clinical benefit for GBM patients.

Printed Organic Light-Emitting Diodes on Fabric with Roll-to-Roll Sputtered ITO Anode and Poly(vinyl alcohol) Planarization Layer

Electronic textiles, which are a combination of fabrics and electronics, can help realize wearable electronic devices by changing the rigidity of these textiles. We demonstrate organic light-emitting diodes (OLEDs) by directly printing the emitting material on fabric substrates using the nozzle-printing technique. Printing the emitting material directly on a fabric substrate with a rough surface is difficult. To address this, we introduce a planarization layer by using a synthesized 3.5 wt % poly(vinyl alcohol) (PVA) solution. The sputtered ITO anode with the thermally annealed PVA planarization layer on a fabric substrate achieves a low sheet resistance in the range of 60-80 Ω/sq, whereas the ITO electrode without a PVA layer exhibits high sheet resistance values of 10-25 kΩ/sq. This result is because the thermally annealed PVA layer on the fabric surface has a uniform surface morphology and a water contact angle as high as 96°, thus acting as a protective layer with a waterproofing effect; in contrast, the water is completely absorbed on the rough surface without a PVA layer. The fabric-based OLEDs with a thermally annealed PVA layer exhibit a lower turn-on voltage of 3 V and higher luminance values of 5346 cd/m² at 8 V compared with the devices without a PVA layer (7 V and 3622 cd/m²) at 18 V. These fabric-based OLEDs with a PVA planarization layer can be produced by the nozzle-printing process and can achieve selective patterning as well as direct printing of the emitting material and ITO sputtering on a fabric substrate; furthermore, they emit well even when it bent into a circle with a radius of 1 cm.

Homogenization of a reaction diffusion equation can explain influenza A virus load data

We study the influence of spatial heterogeneity on the antiviral activity of mouse embryonic fibroblasts (MEF) infected with influenza A. MEF of type Ube1L^-/- are composed of two distinct sub-populations, the strong type that sustains a strong viral infection and the weak type, sustaining a weak viral load. We present new data on the virus load infection of Ube1L^-/-, which have been micro-printed in a checker board pattern of different sizes of the inner squares. Surprisingly, the total viral load at one day after inoculation significantly depends on the sizes of the inner squares. We explain this observation by using a reaction diffusion model and we show that mathematical homogenization can explain the observed inhomogeneities. If the individual patches are large, then the growth rate and the carrying capacity will be the arithmetic means of the patches. For finer and finer patches the average growth rate is still the arithmetic mean, however, the carrying capacity uses the harmonic mean. While fitting the PDE to the experimental data, we also predict that a discrepancy in virus load would be unobservable after only half a day. Furthermore, we predict the viral load in different inner squares that had not been measured in our experiment and the travelling distance the virions can reach after one day.

All-Inkjet-Printed 3D Alveolar Barrier Model with Physiologically Relevant Microarchitecture

With the outbreak of new respiratory viruses and high mortality rates of pulmonary diseases, physiologically relevant models of human respiratory system are urgently needed to study disease pathogenesis, drug efficacy, and pharmaceutics. In this paper, a 3D alveolar barrier model fabricated by printing four human alveolar cell lines, namely, type I and II alveolar cells (NCI-H1703 and NCI-H441), lung fibroblasts (MRC5), and lung microvascular endothelial cells (HULEC-5a) is presented. Automated high-resolution deposition of alveolar cells by drop-on-demand inkjet printing enables to fabricate a three-layered alveolar barrier model with an unprecedented thickness of ≈10 µm. The results show that the 3D structured model better recapitulate the structure, morphologies, and functions of the lung tissue, compared not only to a conventional 2D cell culture model, as expected, but also a 3D non-structured model of a homogeneous mixture of the alveolar cells and collagen. Finally, it is demonstrated that this thin multilayered model reproduce practical tissue-level responses to influenza infection. Drop-on-demand inkjet-printing is an enabling technology for customization, scalable manufacturing, and standardization of their size and growth, and it is believed that this 3D alveolar barrier model can be used as an alternative to traditional test models for pathological and pharmaceutical applications.

Orbital Complexity in Intrinsic Magnetic Topological Insulators MnBi_{4}Te_{7} and MnBi_{6}Te_{10}

Using angle-resolved photoelectron spectroscopy (ARPES), we investigate the surface electronic structure of the magnetic van der Waals compounds MnBi_{4}Te_{7} and MnBi_{6}Te_{10}, the n=1 and 2 members of a modular (Bi_{2}Te_{3})_{n}(MnBi_{2}Te_{4}) series, which have attracted recent interest as intrinsic magnetic topological insulators. Combining circular dichroic, spin-resolved and photon-energy-dependent ARPES measurements with calculations based on density functional theory, we unveil complex momentum-dependent orbital and spin textures in the surface electronic structure and disentangle topological from trivial surface bands. We find that the Dirac-cone dispersion of the topologial surface state is strongly perturbed by hybridization with valence-band states for Bi_{2}Te_{3}-terminated surfaces but remains preserved for MnBi_{2}Te_{4}-terminated surfaces. Our results firmly establish the topologically nontrivial nature of these magnetic van der Waals materials and indicate that the possibility of realizing a quantized anomalous Hall conductivity depends on surface termination.

A compact and stable incidence-plane-rotating second harmonics detector

We describe a compact and stable setup for detecting the optical second harmonics, in which the incident plane rotates with respect to the sample. The setup is composed of rotating Fresnel rhomb optics and a femtosecond ytterbium-doped fiber laser source operating at the repetition frequency of 10 MHz. The setup including the laser source occupies an area of 1 m² and is stable so that the intensity fluctuation of the laser harmonics can be less than 0.2% for 4 h. We present the isotropic harmonic signal of a gold mirror of 0.5 pW and demonstrate the integrity and sensitivity of the setup. We also show the polarization-dependent six-fold pattern of the harmonics of a few-layer WSe₂, from which we infer the degree of local-field effects. Finally, we describe the extensibility of the setup to investigate the samples in various conditions such as cryogenic, strained, ultrafast non-equilibrium, and high magnetic fields.

Bacteriocin production by Leuconostoc citreum ST110LD isolated from organic farm soil, a promising biopreservative

AIMS

The objective of this study was to isolate a bacteriocin-producing strain and to characterize the expressed bacteriocin for the control of Listeria monocytogenes with aim of biopreservation application.

METHODS AND RESULTS

Soil samples from a Korean organic farm were subjected to microbiological analysis for isolation of potential bacteriocinogenic LAB, based on a three-level approach, using L. monocytogenes ATCC 15313 as an indicator test micro-organism. From a total of 17 isolates with inhibitory potential, seven were confirmed to be bacteriocin producers. The selected isolates were differentiated based on their morphology, catalase reaction, sugar fermentation profile obtained by API50CHL and by RAPD-PCR generating two unique profiles. One of the isolates, ST110LD, a specific strong producer of anti-Listeria bacteriocins (12 800 AU ml^-1 ) was identified as Leuconostoc citreum. The proteinaceous nature of the inhibitory compound produced by Leuc. citreum ST110LD was confirmed through treatment with pepsin and α-chymotrypsin. Bacteriocin activity was observed to be not affected by the presence of milk, NaCl, SDS, Tween 80 or glycerol. Bacteriocin ST110LD effectively inhibited the growth of exponentially growing L. monocytogenes ATCC 15313 during a 10-h incubation period in BHI at 37°C. In addition, this bacteriocin showed specific inhibition of only Listeria spp., but did not inhibit the growth of beneficial cultures included in the microbial test panel for assessment of the spectrum of activity.

CONCLUSIONS

Leuconostoc citreum ST110LD was evaluated as safe bacterium strain, producing bacteriocin with high specificity against listerial and enterococcal species. Specificity of producer strain and expressed bacteriocin can be explored in biopreservation of different fermented food products or applied in biotherapy of antibiotic resistant listerial or enterococcal infections.

SIGNIFICANCE AND IMPACT OF THE STUDY

To the best of our knowledge, this is the first report of bacteriocin produced by Leuc. citreum strain with highly specific antimicrobial activity against Listeria sp. and Enterococcus sp.

Sea urchin repelling Tannin- FeIII complex coating for ocean macroalgal afforestation

Intense seaweed grazing by sea urchins has destroyed kelp forests and accelerated the transformation of these forests into barren areas known as urchin barrens. Once the sea urchins occupy the barren ground, it becomes more challenging to restore the kelp forests. Although phlorotannin, a primary herbivore defense chemical secreted by kelp, has been reported to discourage feeding activities of marine herbivores but the direct application of naturally extracted phlorotannin does not effectively repel sea urchins. In this study, we applied a simple and green Tannin-Fe^III (TA-Fe^III) coating on substrates as a sea urchin repellent using a cheap, ecofriendly tannin (TA) obtained from biomass as an alternative to phlorotannin. In a model aquarium experiment, most of the sea urchins (Anthocidaris crassispina) in the tank evaded the TA-Fe^III-coated substrates. In field tests with 300 sea urchins, the majority of sea urchins could not crawl over the TA-Fe^III-coated rope for more than 2 h in contrast to the control group. Hence, the safety, cost-effectiveness, and scalability of the TA-Fe^III coating make it a practical candidate to protect the kelp ecosystem from sea urchins.

A Flexible 3D Organic Preamplifier for a Lactate Sensor

Organic transistors are promising platforms for wearable biosensors. However, the strategies to improve signal amplification have yet to be determined, particularly regarding biosensors that generate very weak signals. In this study, an organic voltage amplifier is presented for a lactate sensor on flexible plastic foil. The preamplifier is based on a 3D complementary inverter, which is achieved by vertically stacking complementary transistors with a shared gate between them. The shared gate is extended and functionalized with a lactate oxidase enzyme to detect lactate. The sensing device successfully detects the lactate concentration in the human sweat range (20-60 mm) with high sensitivity (6.82 mV mm^-1 ) due to high gain of its amplification. The 3D integration process is cost-effective as it is solution-processable and doubles the number of transistors per unit area. The device presented in this study would pave the way for the development of high-gain noninvasive sweat lactate sensors that can be wearable.

Relationship between tumor cell infiltration and 5-aminolevulinic acid fluorescence signals after resection of MR-enhancing lesions and its prognostic significance in glioblastoma

PURPOSE

This study investigated the degree of tumor cell infiltration in the tumor cavity and ventricle wall based on fluorescent signals of 5-aminolevulinic acid (5-ALA) after removal of the magnetic resonance (MR)-enhancing area and analyzed its prognostic significance in glioblastoma.

METHODS

Twenty-five newly developed isocitrate dehydrogenase (IDH)-wildtype glioblastomas with complete resection both of MR-enhancing lesions and strong purple fluorescence on resection cavity were retrospectively analyzed. The fluorescent signals of 5-ALA were divided into strong purple, vague pink, and blue colors. The pathologic findings were classified into massively infiltrating tumor cells, infiltrating tumor cells, suspicious single-cell infiltration, and normal-appearing cells. The pathological findings were analyzed according to the fluorescent signals in the resection cavity and ventricle wall.

RESULTS

There was no correlation between fluorescent signals and infiltrating tumor cells in the resection cavity (p = 0.199) and ventricle wall (p = 0.704) after resection of the MR-enhancing lesion. The median progression-free survival (PFS) and median overall survival (OS) were 12.5 (± 2.1) and 21.1 (± 3.5) months, respectively. In univariate analysis, the presence of definitive infiltrating tumor cells in the resection cavity and ventricle wall was significantly related to the PFS (p = 0.002) and OS (p = 0.027). In multivariate analysis, the absence of definitive infiltrating tumor cells improved PFS (hazard ratio: 0.184; 95% CI: 0.049-0.690, p = 0.012) and OS (hazard ratio: 0.124; 95% CI: 0.015-0.998, p = 0.050).

CONCLUSIONS

After resection both of the MR-enhancing lesions and strong purple fluorescence on resection cavity, there was no correlation between remnant fluorescent signals and infiltrating tumor cells. The remnant definitive infiltrating tumor cells in the resection cavity and ventricle wall significantly influenced the prognosis of patients with glioblastoma. Aggressive surgical removal of infiltrating tumor cells may improve their prognosis.

Paired EMI-HIMU hotspots in the South Atlantic-Starting plume heads trigger compositionally distinct secondary plumes?

Age-progressive volcanism is generally accepted as the surface expression of deep-rooted mantle plumes, which are enigmatically linked with the African and Pacific large low-shear velocity provinces (LLSVPs). We present geochemical and geochronological data collected from the oldest portions of the age-progressive enriched mantle one (EMI)-type Tristan-Gough track. They are part of a 30- to 40-million year younger age-progressive hotspot track with St. Helena HIMU (high time-integrated 238U/204Pb) composition, which is also observed at the EMI-type Shona hotspot track in the southernmost Atlantic. Whereas the primary EMI-type hotspots overlie the margin of the African LLSVP, the HIMU-type hotspots are located above a central portion of the African LLSVP, reflecting a large-scale geochemical zonation. We propose that extraction of large volumes of EMI-type mantle from the margin of the LLSVP by primary plume heads triggered upwelling of HIMU material from a more internal domain of the LLSVP, forming secondary plumes.

Use of inkjet-printed single cells to quantify intratumoral heterogeneity

Quantification of intratumoral heterogeneity is essential for designing effective therapeutic strategies in the age of personalized medicine. In this study, we used a piezoelectric inkjet printer to enable analysis of intratumoral heterogeneity in a bladder cancer for the first time. Patient-derived tumor organoids were dissociated into single cell suspension and used as a bioink. The individual cells were precisely allocated into a microwell plate by drop-on-demand inkjet printing without any additive or treatment, followed by culturing into organoids for further analysis. The sizes and morphologies of the organoids were observed, so as the expression of proliferation and apoptotic markers. The tumor organoids also showed heterogeneous responses against chemotherapeutic agent. Further, we quantified mRNA expression levels of representative luminal and basal genes in both type of tumor organoids. These results verify the heterogeneous expression of various genes among individual organoids. This study demonstrates that the fully automated inkjet printing technique can be used as an effective tool to sort cells for evaluating intratumoral heterogeneity.