Search

Primary amino groups represent an ubiquitous category of functionalities in synthetic building blocks, drugs, and natural products. Therefore, such functionalities offer themselves as perfect handles for late-stage functionalization, and the development of robust and efficient strategies to transform these groups is highly desirable. Despite the extremely challenging activation of the C–N bond, the past few years have witnessed the rapid development of deaminative transformations using pyrylium salts as activating reagents. In most cases, the pyridinium salts formed were activated by single electron transfer, giving alkyl radicals which were used in a series of transformations via nickel and photoredox catalysis. This short review aims to give an overview to related properties of pyrylium salts, their historical significance, and summarize the recent progress in the field of deaminative transformations using these reagents.1 Introduction2 Pyrylium and Pyridinium Salts2.1 Historical Context2.2 Structure and Reactivity2.3 Pyrylium Synthesis2.4 Historical Context of the Reactivity of Pyridinium Salts3 Recent Progress on Deaminative Transformations of Primary Amino Groups by Pyrylium Salts3.1 Metal-Catalyzed Cross-Couplings3.2 Photoredox Catalysis and Photoinduced Reactions for C–C Bond Constructions3.3 Borylations3.4 SNAr Functionalization of Aminoheterocycles4 Conclusion

Immer mehr Unternehmen sind Teil einer jungen, digital gepragten Firmengeneration. Angespornt von den Vorbildern im Silicon Valley revolutionieren sie mit innovativen Technologien und ausgefeilten Geschaftsmodellen gesamte Industrien. Wahrend Google und Co. bereits zu den etablierten Konzernen zahlen, arbeiten sich Start-ups wie der Lieferservice Delivery Hero, die Onlinebank N26, der Mobilitatsanbieter Limebike oder der Carsharingprovider Turo mit ahnlichen Strategien an die Spitze ihrer Industrien.

Objective: To propose a new way to objectively evaluate the external sphincter function prior to male sling surgery. Materials and Methods: We evaluated the pre-operative sphincter function throughout sphincter pressure at rest (SPAR) and sphincter pressure under contraction (SPUC) obtained throughout urethral profilometry profile (UPP) of 10 consecutive patients (age range, 54-79 years) treated with the retrourethral transobturator sling (RTS) for stress urinary incontinence (SUI) because of prostate surgery. The primary endpoint for surgery success rate was post-operative pad weight test. This was correlated to pre-operative pad test, RT, SPAR and SPUC. Post-operatively patients were classified as continent (no pad use) and those who still were incontinent. Results: Mean SPUC in the continent and incontinent group was respectively 188 + 8.8 (median 185.1, range 181 to 201) and 96.9 + 49.4 (median 109.9, range 35.6 to 163.6) (P = 0.008). Mean 24-hour pad test was 151 + 84.2gm (median 140, range 80 to 245) and 973 + 337.1gm (median 1940, range 550 to 1200) in post-operative continent and incontinent groups respectively (P = 0.008). The repositioning test (RT) was positive in all continent patients except one. The RT was also positive in three incontinence patients (false positive). In all post-operative continent patients SPUC was higher than 180cmH2O and pre-operative pad test was less than 245gm. Conclusions: SPUC seems to be a way for optimizing the sphincter evaluation as well to become a useful tool for patient selection prior to RTS surgery.

The quality of SLS products is dramatically degraded by excessive temperature gradients in the thermal profile of the powder bed. Thermal gradients in the presintering temperature, which is defined as powder temperature before laser scans, are inevitable in commercial SLS machines due to various reasons. Such a gradient will propagate to the postsintering temperature, which is defined as the material temperature right after laser scans, if constant laser power is used for sintering. To eliminate thermal gradients in the postsintering temperature, this paper proposes an automatic laser control system to adjust laser power according to the presintering temperature. Infrared cameras are used for presintering temperature measurements, which are used to compute optimal laser power profiles. Two control granularities are implemented: 1) vector-level control eliminates thermal gradients in the postsintering temperature of a single scan line and 2) layer-level control minimizes the difference of postsintering temperature of several areas, each of which consists of a number of scan lines, on the build surface. Experimental results show that variations in the postsintering temperature have been reduced by both implementations (to 60% and 20% respectively) compared to the presintering temperature.

Electronic cigarettes (e-cigarettes) have gained increasing popularity in recent years, mostly because they are supposed to be less harmful than regular cigarettes. Therefore, it is highly imperative to investigate possible noxious effects to protect the consumers. E-liquids consist of propylene glycol, glycerol, aroma compounds and sweeteners. One of these sweeteners is a chlorinated version of sucrose, namely sucralose. The aim of this work was to investigate degradation products of sucralose in the presence of propylene glycol and glycerol at different temperatures of commercially available e-cigarettes. Chemical analysis and biological tests were simultaneously performed on e-liquid aerosol condensates. The results of the chemical analysis, which was executed by employing GC‐MS/GC-FID, demonstrated high amounts of various chloropropanols. The most abundant one is extremely toxic, namely 3-chloropropane-1,2-diol, which can be detected at concentrations ranging up to 10,000 mg/kg. Furthermore, a cytotoxicity investigation of the condensates was performed on HUVEC/Tert2 cells in which metabolic activity was determined by means of resazurin assay. The cellular metabolic activity significantly decreased by treatment with e-liquid aerosol condensate. Due to the results of this study, we advise against the use of sucralose as sweetener in e-liquids.

In breast cancer, undetected lymph node metastases can spread to distal parts of the body for which the 5-year survival rate is only 27%, making accurate nodal metastases diagnosis fundamental to reducing the burden of breast cancer, when it is still early enough to intervene with surgery and adjuvant therapies. Currently, breast cancer management entails a time consuming and costly sequence of steps to clinically diagnose axillary nodal metastases status. The purpose of this study is to determine whether preoperative, clinical DCE MRI of the primary tumor alone may be used to predict clinical node status with a deep learning model. If possible then many costly steps could be eliminated or reserved for only those with uncertain or probable nodal metastases. This research develops a data-driven approach that predicts lymph node metastasis through the judicious integration of clinical and imaging features from preoperative 4D dynamic contrast enhanced (DCE) MRI of 357 patients from 2 hospitals. Innovative deep learning classifiers are trained from scratch, including 2D, 3D, 4D and 4D deep convolutional neural networks (CNNs) that integrate multiple data types and predict the nodal metastasis differentiating nodal stage N0 (non metastatic) against stages N1, N2 and N3. Appropriate methodologies for data preprocessing and network interpretation are presented, the later of which bolster radiologist confidence that the model has learned relevant features from the primary tumor. Rigorous nested 10-fold cross-validation provides an unbiased estimate of model performance. The best model achieves a high sensitivity of 72% and an AUROC of 71% on held out test data. Results are strongly supportive of the potential of the combination of DCE MRI and machine learning to inform diagnostics that could substantially reduce breast cancer burden.

Herbal medicines are commonly used in many countries all around the world. In Western countries they are now gaining more and more popularity, whereas in countries like China and India they have been entrenched for millenniums. Some of these perceived herbal medicines claim to help when suffering from erectile dysfunction. Nevertheless, many of these products are adulterated with PDE5 inhibitors like sildenafil or α-blockers. Patients who suffer from high blood pressure sometimes resort to herbal products, as they are not allowed to take sildenafil because of negative drug-drug interactions with nitrates (often utilized as treatment for coronary diseases). Products which are then adulterated with PDE5 inhibitors, can seriously harm patients. Therefore, this study reports the instant screening of alleged herbal products by employing atmospheric pressure solids analysis probe and high-resolution mass spectrometry to determine adulterants. Three out of 12 investigated products contained sildenafil in ranges from 0.5% to 18%. Multivariate analysis of ambient mass spectrometry measurements revealed encouraging outcomes for distinguishing non-sildenafil and sildenafil adulterated samples. Atmospheric pressure solids analysis probe is therefore a promising method for the rapid determination of sildenafil in herbal products with possible downstream semiquantitative analysis.

Urodynamics testing forms the cornerstone of investigations when it comes to lower urinary tract dysfunction. It has to be done to the highest standards by following the International Continence Society Good Urodynamics Practice protocols. However, with the COVID‐19 pandemic, certain adaptations to the urodynamics procedure need to be considered especially when it comes to quality control. This article aims to define these adaptations to help urodynamicists in their daily practice.

The atomic layer deposition of cobalt using Co(DAD) 2 and tertiary-butyl amine (TBA) has nearly infinite selectivity (>1000 cycles) on metal vs. insulator (SiO 2 or low-k SiCOH) planar samples. However, on patterned samples, selectivity under identical ALD conditions is limited, due to the diffusion of molecularly-adsorbed metal precursor from reactive to non-reactive surfaces. Four strategies have been found to improve Co ALD selectivity: adding a passivant to remove insulator defect sites, increasing the purge time, decreasing the precursor dose, and periodic annealing. The periodic annealing technique allows reabsorption of the Co nuclei from the insulator surface to the growth surface and is consistent with a low temperature reflow process.

INTRODUCTION AND OBJECTIVE:Contemporary post-prostatectomy incontinence (PPI) may be evaluated by many ways like combination of history, number of pads per day (PPD), pad weights, cystoscopy, repos...

Purpose: Many providers elect to use a transcorporeal approach for artificial urinary sphincter placement in an attempt to minimize risks, given the increased risk of complications in revision cases. We present outcomes in a multicenter retrospective analysis of artificial urinary sphincter cuff reimplantation in patients with prior cuff erosion with special consideration given to the transcorporeal approach.Materials and Methods: We compiled a multi-institutional database of patients who underwent artificial urinary sphincter reimplantation after prior urethral erosion. Of the 34 identified patients 24 underwent transcorporeal cuff replacement. Patients with transcorporeal cuff replacement were further analyzed with specific stratification for radiation therapy.Results: The rate of subsequent complications after eroded cuff reimplantation was 32.4% (11 of 34 patients). The most frequent complication was recurrent erosion, which developed in 9 of the 34 patients (26.4%). Repeat artificial urinary sphincte...

Modular assembly and heterologous expression in the moss Physcomitrella patens of pairs of diterpene synthases results in accumulation of modern land plant diterpenoids. Physcomitrella patens is a representative of the ancient bryophyte plant lineage with a genome size of 511 Mb, dominant haploid life cycle and limited chemical and metabolic complexity. For these plants, exceptional capacity for genome editing through homologous recombination is met with recently demonstrated in vivo assembly of multiple heterologous DNA fragments. These traits earlier made P. patens an attractive choice as a biotechnological chassis for photosynthesis-driven production of recombinant peptides. The lack of diterpene gibberellic acid phytohormones in P. patens combined with the recent targeted disruption of the single bifunctional diterpene synthase yielded lines devoid of endogenous diterpenoid metabolites and well-suited for engineering of terpenoid production. Here, we mimicked the modular nature of diterpene biosynthetic pathways found in modern land plants by developing a flexible pipeline to install three combinations of class II and class I diterpene synthases in P. patens to access industrially relevant diterpene biomaterials. In addition to a well-established neutral locus for targeted integration, we also explored loci created by a class of Long Terminal Repeat Retrotransposon present at moderate number in the genome of P. patens. Assembly of the pathways and production of the enzymes from the neutral locus led to accumulation of diterpenes matching the reported activities in the angiosperm sources. In contrast, insights gained with the retrotransposon loci indicate their suitability for targeting, but reveal potentially inherent complications which may require adaptation of the experimental design.

The functionalization of aminoheterocycles by using a pyrylium tetrafluoroborate reagent (Pyry-BF4 ) is presented. This reagent efficiently condenses with a great variety of heterocyclic amines and primes the C-N bond for nucleophilic aromatic substitution. More than 60 examples for the formation of C-O, C-N, C-S, or C-SO2 R bonds are disclosed herein. In contrast to C-N activation through diazotization and polyalkylation, this method is characterized by its mild conditions and impressive functional-group tolerance. In addition to small-molecule derivatization, Pyry-BF4 allows the introduction of functional groups in a late-stage fashion to furnish highly functionalized structures.

The need for the conformal deposition of TiO2 thin films in device fabrication has motivated a search for thermally robust titania precursors with noncorrosive byproducts. Alkylamido-cyclopentadienyl precursors are attractive because they are readily oxidized, yet stable, and afford environmentally mild byproducts. We have explored the deposition of TiO2 films on OH-terminated SiO2 surfaces by in situ Fourier transform infrared spectroscopy using a novel titanium precursor [(EtCp)Ti(NMe2)3 (1), Et = CH2CH3] with either ozone or water. This precursor initially reacts with surface hydroxyl groups at ≥150 °C through the loss of its NMe2 groups. However, once the precursor is chemisorbed, its subsequent reactivities toward ozone and water are very different. There is a clear reaction with ozone, characterized by the formation of monodentate formate and/or chelate bidentate carbonate surface species; in contrast, there is no detectable reaction with water. For the ozone-based ALD process, the surface formate/c...

In this paper, we present a possible control paradigm for swarms of mobile agents with limited communication capabilities. The control paradigm is based on communication and movement strategies from slime mould, that uses 1-bit communication for various behaviours of the super organism. We have found that by varying minor details of the classical slime mould based communication strategies and movement cues it is possible to generate substantially different behaviours and features that the swarm is able to perform. Swarm size estimation, pinging synchronization, ego positioning etc. are some behaviours which can be generated by varying minor details of the basic slime mould based communication and movement strategies. Additionally, using several different signals within the swarm and combining them, it is possible to generate an open control paradigm, that allows to construct different behaviours, not bases on the design of individual behaviour but by design of different interacting travelling waves on the different signal layers in the swarm.

Recent years saw an increase in computation power on Internet of things devices such as the Raspberry Pi. It is now common for such platforms to boast multiple CPU-cores with clock rates of 1 gigahertz and higher. We have taken this evolution as a motivator to see how far we can push the limit in performing complex operations on a large amount of data by implementing a passive radar system on the Raspberry Pi. To keep the costs of our system further down, we evaluated the use of low-cost RTL-SDR receivers. Our work shows that today's IoT devices allow real-time processing for passive radar applications for both, FM and DAB signals. With our low-cost receiver, we were able to receive echos of aircraft several kilometers away.

The low-temperature (≤400 oC) deposition of polycrystalline AlN films on silicon is demonstrated by atomic layer annealing (ALA) using either trimethyl aluminum (TMA) and anhydrous hydrazine (N2H4) or tris(dimethylamido) aluminum (TDMAA) and anhydrous N2H4 with an argon plasma treatment utilizing a DC bias to tune the ion energy. Using TDMAA and N2H4, high-quality AlN films are deposited with large grain size and low oxygen/carbon contamination which can be used as a templating layer for further high-speed AlN film growth via sputtering. The deposition of high-quality AlN films deposited by ALA are successfully used as templates for sputtered AlN resulting in a >2x improvement in average grain size when compared to an analogous amorphous template layer.

The semiconductor-to-metal transition of vanadium dioxide (VO2) films is studied using temperature-dependent Raman, optical, and electrical measurements. The VO2 films are deposited via an atomic layer deposition (ALD) process using alternate pulses of vanadium tetrachloride and H2O at 350 °C. A growth rate of 0.021 nm/cycle and a thickness of 33 nm of VO2 are obtained for all films studied. The phase of the film is determined using x-ray diffraction. The as-deposited films are amorphous and are transformed to the monoclinic phase with a post-deposition, forming gas anneal at temperatures ≥ 500 °C for 60 min. The purity of the films is determined using x-ray photoelectron spectroscopy and no evidence of residual chlorine is detected. The temperature-dependent Raman Ag mode of the monoclinic VO2 phase is observed to monotonically decrease from 25 °C to 78 °C; where no evidence of the Ag peak is observed in the film beyond 68 °C. The refractive index and extinction coefficient extracted from temperature-dependent ellipsometry confirm that, beyond 68 °C, free carriers are generated in the film. Electrical measurements performed on a fabricated p++Si/VO2/Ti/Au device show a semiconductor-to-metal transition behavior with a high resistance of 14701 ± 2284 Ω at 62 °C and a low resistance of 1064.1 ± 143 Ω at 67 °C. This work demonstrates that a halide-based ALD process provides a clean and robust approach to synthesizing high-quality VO2 films.

Grain-scale microstructure evolution during additive manufacturing is a complex physical process. As with traditional solidification methods of material processing (e.g. casting and welding), microstructural properties are highly dependent on the solidification conditions involved. Additive manufacturing processes however, incorporate additional complexity such as remelting, and solid-state evolution caused by subsequent heat source passes and by holding the entire build at moderately high temperatures during a build. We present a three-dimensional model that simulates both solidification and solid-state evolution phenomena using stochastic Monte Carlo and Potts Monte Carlo methods. The model also incorporates a finite-difference based thermal conduction solver to create a fully integrated microstructural prediction tool. The three modeling methods and their coupling are described and demonstrated for a model study of laser powder-bed fusion of 300-series stainless steel. The investigation demonstrates a novel correlation between the mean number of remelting cycles experienced during a build, and the resulting columnar grain sizes.

NoMoS is a novel momentum spectrometer with which we aim to measure the spectra of the charged neutron beta decay products with high precision. The shape of the proton and electron spectra can inter alia be used for the determination of the electron-antineutrino correlation coefficient $a$ and the Fierz interference term $b$, respectively. These observables can in turn be used to test the Standard Model of Particle Physics and to search for extensions thereof. NoMoS utilizes the $R \times B$ drift effect present in curved magnetic fields, which disperses charged particles according to their momentum. In this paper, we report on selected recent investigations that were conducted with regard to the magnet design and the detection system., 5 pages, 2 figures, accepted in JPCS of the INPC 2019 conference

[Image: see text] Selective optimization of side activities is a valuable source of novel lead structures in drug discovery. In this study, a computer-aided approach was used to deorphanize the pleiotropic cholesterol-lowering effects of the beta-blocker talinolol, which result from the inhibition of the enzyme soluble epoxide hydrolase (sEH). X-ray structure analysis of the sEH in complex with talinolol enables a straightforward optimization of inhibitory potency. The resulting lead structure exhibited in vivo activity in a rat model of diabetic neuropatic pain.

One main motivation for studying swarm intelligence comes from observing the resilience of living systems in nature. Swarm intelligence has provided important inspirations for the engineering of technical systems. The swarmtaxis algorithm and the FSTaxis algorithm are swarm intelligent algorithms that aim to move a group of agents from a starting point to a predefined goal. The swarmtaxis algorithm bases its state transition on a voting like mechanism in which the agents count the number of “pings” they get from their surroundings. In contrast, the FSTaxis algorithm uses a scroll wave based communication mechanism inspired by slime mold and fireflies. The scroll wave based communication is expected to be more resilient than the voting like mechanism of the swarmtaxis algorithm. In this paper, we borrow the communication mechanism used in FSTaxis algorithm to improve the swarmtaxis algorithm. We will also discuss how this modified algorithm performs in comparison to the parent algorithm.

Design and manufacture of a novel varifocal freeform optics by means of high-resolution 3D printing are presented. Tuning of its focal length is achieved by mutually rotating two lens bodies around the optical axis.

This paper presents the design of a novel varifocal freeform optics consisting of two lens bodies each with a helical-type surface structure of azimuthally varying curvatures. This arrangement allows for tuning the optical refraction power by means of a mutual rotation of the lens bodies around the optical axis. Thus, the refraction power can be tuned continuously in a defined range. The shape of the helical-type surfaces is formed by a change in curvature subject to the azimuthal angle α. At the transition of the azimuthal angle from α = 2π to α = 0, a surface discontinuity appears. Since this discontinuity will seriously affect the imaging quality, it has to be obscured. In the initial state, i.e. zero-degree rotation, the curvatures of the opposing surfaces result in a specific refraction power, which is constant over the entire circular aperture. Rotating one of the lens bodies by an angle φ around the optical axis will change the opposing curvatures and result in a change of refraction power. Two circular sectors with different tunable optical refraction powers are formed, thus resulting in a tunable bifocal optics. Obscuring the minor sector will result in a tunable monofocal rotation optics. In contrast to conventional tunable lens systems, where additional space for axial or lateral lens movement has to be allocated in design, rotation optics allowing for a more compact design. A simulative performance analysis of the rotation optics in dependence of the maximum rotation angle will be presented as well as an approach to design-for-manufacture.

Extending the charge lifetime of today’s spin polarized GaAs photoelectron guns from tens to thousands of Coulombs is a requirement for long-duration operation at milliampere beam current. There are two main approaches frequently considered to achieve this goal. The first is improving photo-gun vacuum, which provides a direct means to minimize the ill effects of ion bombardment and associated QE decay. In this contribution, we demonstrate the second: enhancing the charge lifetime at milliampere beam current by using large laser spots which serves to distribute ion damage over a larger region of the photocathode. The efficacy of this approach was presented at past workshops, but using bulk GaAs and green laser light without RF structure. In this contribution, highly polarized beam was produced from strained-superlattice GaAs/GaAsP photocathodes inside the 130 kV photo-gun at the CEBAF photoinjector, at beam currents from 0.5 to 1.5 mA and with a clear indication of lifetime enhancement using laser beams as large as ~8 mm$^2$. However, when the laser beam size was increased beyond this diameter, further lifetime enhancement was not observed which highlights the importance of proper cathode/anode design to maintain loss-free beam delivery and the preservation of static vacuum conditions. In addition, this contribution presents electron beam polarization measurements at currents to 1 mA.

Background The increasing armamentarium of disease-modifying therapies in multiple sclerosis is accompanied by potentially severe adverse effects. The cell-adhesion molecule CD62L, which facilitates leukocyte extravasation, has been proposed as a predictive marker for treatment tolerability. However, pre-analytical procedures might impact test results, thereby limiting its clinical usability. Whether the immediate analysis of CD62L expression of peripheral blood mononuclear cells can aid treatment decision making is yet unclear. Objective To investigate the effect of various disease-modifying therapies in multiple sclerosis on CD62L expression of CD3+CD4+ peripheral blood mononuclear cells in freshly collected blood samples. Methods We collected peripheral blood samples from patients with clinically isolated syndrome and multiple sclerosis (baseline/follow up n = 234/ n = 98) and healthy controls ( n = 51). CD62L+CD3+CD4+ expression was analysed within 1 hour by fluorescence-activated cell sorting. Results CD62L+CD3+CD4+ expression was significantly decreased in patients treated with natalizumab ( n = 26) and fingolimod ( n = 20) and increased with dimethyl-fumarate ( n = 15) compared to patients receiving interferon/glatiramer acetate ( n = 90/30) or no disease-modifying therapies ( n = 53) and controls ( n = 51) ( pConclusion CD62L+CD3+CD4+ expression is altered in patients treated with different disease-modifying therapies when measured in freshly collected samples. The clinical meaning of CD62L changes under disease-modifying therapies warrants further investigation.

The aviation industry's increasing reliance on GPS to facilitate navigation and air traffic monitoring opens new attack vectors with the purpose of hijacking UAVs or interfering with air safety. We propose Crowd-GPS-Sec to detect and localize GPS spoofing attacks on moving airborne targets such as UAVs or commercial airliners. Unlike previous attempts to secure GPS, Crowd-GPS-Sec neither requires any updates of the GPS infrastructure nor of the airborne GPS receivers, which are both unlikely to happen in the near future. In contrast, Crowd-GPS-Sec leverages crowdsourcing to monitor the air traffic from GPS-derived position advertisements that aircraft periodically broadcast for air traffic control purposes. Spoofing attacks are detected and localized by an independent infrastructure on the ground which continuously analyzes the contents and the times of arrival of these advertisements. We evaluate our system with real-world data from a crowdsourced air traffic monitoring sensor network and by simulations. We show that Crowd-GPS-Sec is able to globally detect GPS spoofing attacks in less than two seconds and to localize the attacker up to an accuracy of 150 meters after 15 minutes of monitoring time.

In recent times, we have witnessed a trend in which communications data is increasingly collected and made open source by the public. A prominent example is the tracking of aircraft movements using unencrypted air traffic control (ATC) communication. This paper studies the implications of such new open source aircraft datasets on the operational privacy of military and government actors. We use publicly available aircraft metadata in conjunction with unfiltered ATC communication gathered from the collaborative sensor network OpenSky. We show that using these datasets, it is possible to collect, process and analyze large numbers of movements in an automated fashion, providing insights into potentially sensitive operations.

Selective laser sintering (SLS) is an additive manufacturing technique for rapidly creating parts directly from a computer-aided design (CAD) model by using a laser to fuse successive layers of powder. However, better understanding of the effect of particle-level variations on the overall build quality is needed. In this work, we investigated these effects computationally by considering the role of the particle size distribution and variations in the powder bed depth to mimic the part complexity found in overhangs and protrusions. In addition, the results from these studies can be distilled to obtain better effective material properties such as laser absorptivity and laser extinction coefficient that are needed for continuum models of the process. We implement a Monte Carlo ray-tracing algorithm within the discrete element model in the open-source simulation software MFiX. Random, loose-packed, particle bed structures are generated, and effective absorptivity and extinction coefficients are calculated. Results are compared against previous computational and experimental measurements for free, monodisperse, and deep powder beds, with good agreement being obtained. Correlations along with uncertainties are developed to allow the effective absorptivity and extinction coefficient as a function of various particle and operational parameters to be accurately set in SLS macroscale models.

Selective laser melting (SLM) is a widely used powder-based additive manufacturing process. However, it can be difficult to predict how process inputs affect the quality of parts produced. Computational modeling has been used to address some of these difficulties, but a challenge has been accurately capturing the behavior of the powder in a large, bed-scale model. In this work, a multiscale melting model is implemented to simulate the melting of powder particles for SLM. The approach employs a particle-scale model for powder melting to develop a melt fraction–temperature relationship for use in bed-scale simulations of SLM. Additionally, uncertainties from the particle-scale are propagated through the relationship to the bed scale, thus allowing particle-scale uncertainties to be included in the bed-scale uncertainty estimation. Relations, with uncertainty, are developed for the average melt fraction of the powder as a function of the average temperature of the powder. The utility of these melt fraction–temperature relations is established by using them to model phase change using a continuum bed-scale model of the SLM process. It is shown that the use of the developed relations captures partial melt behavior of the powder that a simple melting model cannot. Furthermore, the model accounts for both uncertainty in material properties and packing structure in the final melt fraction–temperature relationship, unlike simple melting models. The developed melt fraction–temperature relations may be used for bed-scale SLM simulations with uncertainty due to particle effects.

This paper presents the research done in the field of robotic cultural evolution in challenging real world environments. We hereby present these efforts, as part of project subCULTron, where we will create an artificial society of three cooperating sub-cultures of robotic agents operating in a challenging real-world habitat. We introduce the novel concept of “cultural learning”, which will allow a swarm of agents to locally adapt to a complex environment and exchange the information about this adaptation with other subgroups of agents. Main task of the presented robotic system is autonomous environmental monitoring including self organised task allocation and organisation of swarm movement processes. One main focus of the project is on the development and implementation of bio-inspired controllers, as well as novel bio-inspired sensor systems, communication principles, energy harvesting and morphological designs. The main scientific objective is to enable and study the emergence of a collective long-term autonomous cognitive system in which information survives the operational lifetime of individuals, allowing cross-generation learning of the society by self-optimising.

In nature, the combination of processes of emotion and cognition has a deep impact on type and quality of reaction to environmental stimuli. In this work, we want to test the feasibility of artificial hormones in artificial neural networks. We take a minimal evolving neural network and look into the implications and opportunities of extending this model of communicating nodes, with one virtual hormone gland. To explore the differences in behavior, that we expect to develop with this modification, we modify an already well established model, the Braitenberg Vehicle. These vehicles were faced with a simple energy gathering task. The behavior, efficiency and fitness of these vehicles in identical environment, with the artificial hormone active and inactive, is examined. It shows, that the implementation of artificial emotion leads to an increase in efficiency of the evolved solution.

Selective laser melting (SLM) is a powder-based additive manufacturing technique which creates parts by fusing together successive layers of powder with a laser. The quality of produced parts is highly dependent on the proper selection of processing parameters, requiring significant testing and experimentation to determine parameters for a given machine and material. Computational modeling could potentially be used to shorten this process by identifying parameters through simulation. However, simulating complete SLM builds is challenging due to the difference in scale between the size of the particles and laser used in the build and the size of the part produced. Often, continuum models are employed which approximate the powder as a continuous medium to avoid the need to model powder particles individually. While computationally expedient, continuum models require as inputs effective material properties for the powder which are often difficult to obtain experimentally. Building on previous works which have developed methods for estimating these effective properties along with their uncertainties through the use of detailed models, this work presents a part scale continuum model capable of predicting residual thermal stresses in an SLM build with uncertainty estimates. Model predictions are compared to experimental measurements from the literature.

In silico screening of DrugBank database to detect liver X receptor (LXR) agonism of marketed drugs using a self-organizing map and successive LXR-Gal4 hybrid reporter gene assay evaluation in vitro discovered alitretinoin and bexarotene as partial liver X receptor agonists. Dose-response curves demonstrated that plasma concentrations observed in clinical trials are sufficient for LXR activation and thus could account for LXR-mediated side-effects such as hypercholesterolemia and hyperlipidemia. The discovered drugs are the first reported dual LXR/RXR agonists and can serve as lead structures for LXR and dual LXR/RXR modulator development.

In this work, a discrete element model (DEM) is developed and implemented in the open source flow solver MFiX to simulate the effective thermal conductivity of powder beds for selective laser sintering (SLS) applications, considering scenarios common in SLS such as thin beds, high temperatures, and degrees of powder consolidation. Random particle packing structures of spherical particles are generated and heat transfer between the particles is calculated. A particle–particle contact conduction model, a particle–fluid–particle conduction model, and a view factor radiation model using ray-tracing for calculation of view factors and assuming optically thick particles are used. A nonlinear solver is used to solve for the particle temperatures that drive the net heat transfer to zero for a steady state solution. The effective thermal conductivity is then calculated from the steady state temperature distribution. Results are compared against previously published experimental measurements for powder beds and good agreement is obtained. Results are developed for the impacts of very high temperatures, finite bed depth, consolidation, Young's modulus, emissivity, gas conductivity, and polydispersity on effective thermal conductivity. Emphasis is placed on uncertainty quantification in the predicted thermal conductivity resulting from uncertain inputs. This allows SLS practitioners to control the inputs to which the thermal response of the process is most sensitive.