KTH Royal Institute of Technology

Alternating macrocyclization and polymerization was observed in dynamic nitroaldol reaction systems. The reaction of an aromatic dialdehyde reacting with linear α,ω‐dinitroalkanes with even numbers of carbon atoms favored the formation of lowellane macrocycles, while the reactions involving dinitrocompounds consisted of odd numbers of carbon atoms promoted polymerization. The folding patterns of the alkyl chains played an important factor in determining the outcome of the reactions.

Laminar–turbulent transition on the suction surface of the LM45.3p blade ( $20\,\%$ thickness) was investigated using wall-resolved large eddy simulation (LES) at a chord Reynolds number of $Re_c=10^6$ and angle of attack $4.6^\circ$ . The effects of anisotropic free stream turbulence (FST) with intensities $TI=0\,\%$ – $7\,\%$ were examined, with integral length scales scaled down from atmospheric measurements. At $TI=0\,\%$ , a laminar separation bubble (LSB) forms and transition is initiated by Kelvin–Helmholtz vortices. At low FST levels ( $0\,\%\lt TI \leqslant 2.4\,\%$ ), robust streak growth via the lift-up mechanism suppresses the LSB, while transition dynamics shifts from two-dimensional Tollmien–Schlichting (TS) waves ( $TI=0.6\,\%$ ) to predominantly varicose inner and outer instabilities ( $TI=1.2\,\%$ and $2.4\,\%$ ) induced by the wall-normal shear and inflectional velocity profiles. The critical disturbance kinetic energy scales with $TI^{-1.80\pm 0.11}$ , compared with $TI^{-2.40}$ from Mack’s correlation. For $TI\geqslant 4.5\,\%$ , bypass transition dominates, driven by high-frequency boundary layer perturbations and streak breakdown via outer sinuous modes induced by the spanwise shear and inflectional velocity profiles. The scaling of streak amplitudes with TI becomes sub-linear and spanwise non-uniformity characterises the turbulent breakdown. The critical disturbance kinetic energy reduces to $TI^{-0.90\pm 0.16}$ , marking a transition regime distinct from modal mechanisms. The onset of bypass transition ( $TI\approx 2.4\,\%{-}4.5\,\%$ ) aligns with prior studies of separated and flat-plate flows. A proposed turbulence spectrum cutoff links atmospheric measurements to wind tunnel data and Mack’s correlation, offering a framework for effective TI estimation in practical environments.

The electroglottographic (EGG) signal offers a non-invasive approach to analyze phonation. It is known, if not obvious, that the onset of vocal fold contacting has a substantial effect on how the vocal folds vibrate and on the quality of the voice. Given that the presence or absence of vocal fold contacting has major consequences also for the interpretation of acoustic metrics, it is compelling to consider the possibility of predicting EGG signals directly from the microphone speech signal. This retrospective study presents a neural network model for EGG signal estimation utilizing a WaveNet architecture augmented with a self-attention mechanism. The model was trained on an existing dataset that comprehensively recorded participants' full voice range. The proposed model effectively captures the temporal dynamics and morphological characteristics of normophonic EGG waveforms, achieving outputs that closely resemble the ground truth in terms of EGG waveshape and extracted EGG metrics. For evaluation, voice mapping was used to display the distribution similarities of extracted metrics from predicted and ground truth EGG waveforms. The model exhibits proficiency in accurately estimating EGG signals in areas of stable and contacting voicing but displays reduced accuracy in transitional and breathy phonatory conditions.

The elastic properties of nanoscale extracellular vesicles (EVs) are believed to influence their cellular interactions, thus having a profound implication in intercellular communication. However, accurate quantification of their elastic modulus is challenging due to their nanoscale dimensions and their fluid-like lipid bilayer. We show that the previous attempts to develop atomic force microscopy-based protocol are flawed as they lack theoretical underpinning as well as ignore important contributions arising from the surface adhesion forces and membrane fluctuations. We develop a protocol comprising a theoretical framework, experimental technique, and statistical approach to accurately quantify the bending and elastic modulus of EVs. The method reveals that membrane fluctuations play a dominant role even for a single EV. The method is then applied to EVs derived from human embryonic kidney cells and their genetically engineered classes altering the tetraspanin expression. The data show a large spread; the area modulus is in the range of 4 to 19 mN/m and the bending modulus is in the range of 15 to 33 k B T , respectively. Surprisingly, data for a single EV, revealed by repeated measurements, also show a spread that is attributed to their compositionally heterogeneous fluid membrane and thermal effects. Our protocol uncovers the influence of membrane protein alterations on the elastic modulus of EVs.

In this study, we introduce a cost-effective antenna designed for ultrawideband (UWB) spectrum. The antenna employs a single-layer coplanar waveguide (CPW) feed on a 1.6 mm FR4 board. Notably, the antenna demonstrates a bandwidth from 3.7 to 15.7 GHz (12 GHz) for a single element. Expanding its utility, a four-element Multiple Input Multiple Output (MIMO) assembly is arranged orthogonally, aiming to achieve diversity characteristics. The MIMO elements are connected through a common ground plane. In the MIMO configuration, the bandwidth response is increased to 2.9–16.2 GHz. To mitigate mutual coupling between the antenna elements, a simple geometric parasitic element is inserted between them, resulting in a significant improvement of 15 dB in isolation. In addition, a maximum gain of 5.5 dBi is noted at 14 GHz with total efficiency exceeding 80% throughout the resonance bandwidth. The individual antenna element boasts a compact footprint of 20 × 26 mm², while the MIMO configuration occupies an area of 46 × 48 mm². Furthermore, we conduct a thorough analysis of various MIMO performance metrics, including the envelope correlation coefficient (ECC), mean effective gain (MEG), and diversity gain (DG), all of which fall within acceptable thresholds. These analyses validate the potential of our proposed UWB–MIMO antenna for diverse UWB applications.

Despite decades of research on the emergence of human speech capacities, an integrative account consistent with hominin evolution remains lacking. We review paleoanthropological and archaeological findings in search of a timeline for the emergence of modern human articulatory morphological features. Our synthesis shows that several behavioral innovations coincide with morphological changes to the would-be speech articulators. We find that significant reductions of the mandible and masticatory muscles and vocal tract anatomy coincide in the hominin fossil record with the incorporation of processed and (ultimately) cooked food, the appearance and development of rudimentary stone tools, increases in brain size, and likely changes to social life and organization. Many changes are likely mutually reinforcing; for example, gracilization of the hominin mandible may have been maintainable in the lineage because food processing had already been outsourced to the hands and stone tools, reducing selection pressures for robust mandibles in the process. We highlight correlates of the evolution of craniofacial and vocal tract features in the hominin lineage and outline a timeline by which our ancestors became ‘pre-adapted’ for the evolution of fully modern human speech.

This study aimed to provide a multiangled comparison of the impact of real and virtual setups on the behaviour and perception of electric scooter (e-scooter) riding to examine the external validity of the virtual environments in the micro-mobility context. For this purpose, a within-subject design experiment was conducted to collect data on the behaviour of e-scooter riders. Furthermore, self-reported data on mental and physical demand as well as physiological data in the form of heart rate measurements and electroencephalography (EEG) were recorded to provide an additional insight into the behavioural results. The analysis was based on the multinomial logit model (MNL) for the behavioural data, ordered logit models for self-reported measures. Parametric and non-parametric tests were performed to capture the differences in physiological data. The results of the behavioural data showed significant differences in braking and acceleration patterns between virtual and real scenarios, which undermined the external validity of virtual environments in the current context. Further, self-reported measures painted a mixed picture when looked at jointly with biometric measures, where the questionnaires indicated that both setups were indifferent with respect to mental demand, while the physiological data suggested that virtual scenarios were more mentally engaging for the e-scooter riders.

Aromatic compounds serve as key feedstocks in the chemical industry, typically undergoing functionalization or full reduction. However, partial reduction via dearomative sequences remains underexplored despite its potential to rapidly generate complex three-dimensional scaffolds and the existing dearomative strategies often require metal-mediated multistep processes or suffer from limited applicability. Herein, a photocatalytic radical cascade approach enabling dearomative difunctionalization through selective spirocyclization/imination of nonactivated arenes is reported. The method employs bifunctional oxime esters and carbonates to introduce multiple functional groups in a single step, forming spirocyclic motifs and iminyl functionalities via N–O bond cleavage, hydrogen-atom transfer, radical addition, spirocyclization, and radical-radical cross-coupling. The reaction constructs up to four bonds (C−O, C−C, C−N) from simple starting materials. Its broad applicability is demonstrated on various substrates, including pharmaceuticals, and it is compatible with scale-up under flow conditions, offering a streamlined approach to synthesizing highly decorated three-dimensional frameworks.

Plain Language Summary Understanding how non‐aqueous phase liquid (NAPL) gets trapped in the subsurface is important for cleaning up NAPL contamination in groundwater. While previous studies have investigated how NAPLs get trapped and dissolved in subsurface within porous media, NAPL entrapment mechanisms are not well understood for fractured systems. To investigate NAPL entrapment architectures and underlying mechanisms, we conducted experiments using a microfluidic setup to investigate how NAPL gets trapped as water flows through and displaces NAPL in real‐time. We identified three main patterns of NAPL entrapment: Pools Pattern (PP), Mixed Pattern (MP), and Ganglia Pattern (GP). These patterns are based on how NAPL behaves at the pore scale. PP emerges due to capillary forces causing water to bypass certain areas and creating NAPL pools. GP is caused by viscous forces creating NAPL ganglia. MP results from a combination of both capillary and viscous forces induced trapping mechanism. Two key factors, the aperture heterogeneity (anisotropy and roughness) and the water flow rate, influence how these forces compete and how resulting residual patterns form. Our findings help in predicting how NAPL will be trapped in rock fractures by looking at measurable aspects like fracture structure and flow rate, aiding in better management and remediation of NAPL‐contaminated groundwater.

Background The emergence and dissemination of antibiotic resistance represents a significant and ever-increasing global threat to human, animal, and environmental health. The explosive proliferation of resistance has ultimately been seen in all clinically used antibiotics. Infections caused by antibiotic-resistant bacteria have been associated with an estimated 4,950,000 deaths annually, with extremely limited therapeutic options and only a few new antibiotics under development. To combat this silent pandemic, a better understanding of the molecular mechanisms of antibiotic resistance is immensely needed, which not only helps to improve the efficacy of current drugs in clinical use but also design new antimicrobial agents that are less susceptible to resistance. Results The past few years have witnessed a number of new advances in revealing the molecular mechanisms of AMR. Following five sophisticated mechanisms (efflux pump, antibiotics inactivation by enzymes, alteration of membrane permeability, target modification, and target protection), the roles of various novel proteins/enzymes in the acquisition of antibiotic resistance are constantly being described. They are widely used by clinical bacterial strains, playing a key role in the emergence of resistance. Conclusion While most of these have so far received less attention, expanding our understanding of these emerging resistance mechanisms is of crucial importance to combat the antibiotic resistance crisis in the world. This review summarizes recent advances in our knowledge of emerging resistance mechanisms in bacteria, providing an update on the current antibiotic resistance threats and encouraging researchers to develop critical strategies for overcoming the resistance.

This study employs spectral proper orthogonal decomposition (SPOD) on direct numerical simulation data from a low-pressure turbine (LPT) operating under high freestream turbulence levels. The impacts of upstream wakes on the transition process are assessed by considering both cases with and without wakes, modeled by a moving cylinder placed upstream of the LPT blade. In the absence of upstream wakes, the SPOD eigenvalues decreases almost monotonically as frequency increases. At high frequencies, the spectra reveal a broadband interval with minimal elevation, corresponding to the Kármán vortex streets formed downstream of the blade's trailing edge. The SPOD modes in this inflow condition show fully attached boundary layers across the entire blade, suggesting that the boundary layers may be transitional. When subjected to upstream wakes, however, the SPOD spectra display several intense peaks linked to the wake passage frequencies. The associated SPOD modes reveal turbulent spots and lambda vortices on the rear suction side of the blade, typical indicators of turbulent boundary layers. Between the fundamental passage frequency and its harmonics, a series of tones emerge, representing the Doppler-shifted wakes. Triadic interactions between modes involving upstream wakes and their translation induce a cascade of these intermediate components, as verified by the bispectrum map. The SPOD modes capture interactions of structures carried by upstream wakes and the freestream flow with the blade boundary layers, manifested as low- and high-velocity streaks whose breakdown promotes the transition. High-frequency modes describe coherent structures break down into the vortex streets at the trailing edge.

The fermionic von Neumann entropy, the fermionic entanglement entropy and the fermionic relative entropy are defined for causal fermion systems. Our definition makes use of entropy formulas for quasi-free fermionic states in terms of the reduced one-particle density operator. Our definitions are illustrated in various examples for Dirac spinors in two- and four-dimensional Minkowski space, in the Schwarzschild black hole geometry and for fermionic lattices. We review area laws for the two-dimensional diamond and a three-dimensional spatial region in Minkowski space. The connection is made to the computation of the relative entropy using modular theory.

This study evaluated the hemodynamic effects, discomfort, and energy efficiency of low-intensity neuromuscular electrical stimulation (LI-NMES) of the calf delivered via sock-integrated transverse textile electrodes (TTE) at different frequencies and plateau times. Fifteen healthy participants underwent NMES stimulation through 3 × 3 cm TTE with ten combinations of frequency (1–36 Hz) and plateau times (0.5–7 s). NMES was increased until plantar flexion occurred, at which point ultrasound-measurements were made of popliteal peak venous velocity (PVV), time-averaged mean velocity (TAMV), average duration of blood flow pulse (ADBP) and ejection volume (EV). Discomfort (NRS, 0–10), current amplitude, and energy consumption were recorded. Median values were analyzed with significance set at p < 0.05. Both 1 Hz and 36 Hz C-LI-NMES significantly improved PVV and TAMV (p ≤ 0.008). EV increased significantly for plateau times of 1.5, 5.0, and 7.0 s (p < 0.05). Compared to 36 Hz, 1 Hz showed significantly lower discomfort (NRS: 0.4 vs. 1.6) and energy consumption (0.4 vs. 31.3 mJ, both p ≤ 0.01) but required higher current amplitude (33.2 vs. 23.3 mA, p < 0.01) to reach plantar flexion. The study concludes that both 1 Hz and 36 Hz frequency improve venous hemodynamics, but 1 Hz stimulation minimizes discomfort and energy use while maintaining effectiveness. Trial registration: Retrospectively registered with Clinical Trials, trial ID: NCT06082297.

The study examines supersonic square jets in a twin nozzle configuration with the aim of identifying and characterising emergent instability modes during overexpanded operation. Unlike screeching rectangular jets that undergo strong fluctuations normal to the wider jet dimension, the equilateral nature of the exit geometry in square nozzles leads to multiple instability states dictated by shock–turbulence interactions and nozzle operating conditions. Furthermore, strong coupling modes between the jets were identified that led to either phase locked or out of phase interactions of the inner shear layers. Results from experimental studies were examined using spatial and temporal decomposition techniques based on spectral methods to identify the resultants from triadic shock–turbulence interactions. The primary instability mode across both operating conditions were driven by optimal interactions while the harmonics were found to be associated with the suboptimal shock–turbulence interactions.

We report an anomalous capillary phenomenon that reverses typical capillary trapping via nanoparticle suspension and leads to a counterintuitive self-removal of non-aqueous fluid from dead-end structures under weakly hydrophilic conditions. Fluid interfacial energy drives the trapped liquid out by multiscale surfaces: the nanoscopic structure formed by nanoparticle adsorption transfers the molecular-level adsorption film to hydrodynamic film by capillary condensation, and maintains its robust connectivity, then the capillary pressure gradient in the dead-end structures drives trapped fluid motion out of the pore continuously. The developed mathematical models agree well with the measured evolution dynamics of the released fluid. This reversing capillary trapping phenomenon via nanoparticle suspension can be a general event in a random porous medium and could dramatically increase displacement efficiency. Our findings have implications for manipulating capillary pressure gradient direction via nanoparticle suspensions to trap or release the trapped fluid from complex geometries, especially for site-specific delivery, self-cleaning, or self-recover systems.

Within Industry 5.0, human-centric smart manufacturing stands out for its adaptability and responsiveness, effortlessly combining information technology (IT) and artificial intelligence (AI) to optimize operations on both local and global levels. Methodologies combine advanced computational technologies with state-of-the-art manufacturing tools, creating systems that are naturally flexible, enhancing human capabilities, and encouraging creativity. This chapter aims to outline expected advancements and strategic pathways for improving practical applications in forward-looking human-centric smart manufacturing systems. These include human-in-the-loop robot learning, multi-modal interaction, industrial embodied intelligence, and Trustworthy AI (TAI).