The role of artificial intelligence in generating original scientific research

Artificial intelligence (AI) is a revolutionary technology that is finding wide application across numerous sectors. Large language models (LLMs) are an emerging subset technology of AI and have been developed to communicate using human languages. At their core, LLMs are trained with vast amounts of information extracted from the internet, including text and images. Their ability to create human-like, expert text in almost any subject means they are increasingly being used as an aid to presentation, particularly in scientific writing. However, we wondered whether LLMs could go further, generating original scientific research and preparing the results for publication. We taskedGPT-4, an LLM, to write an original pharmaceutics manuscript, on a topic that is itself novel. It was able to conceive a research hypothesis, define an experimental protocol, produce photo-realistic images of 3D printed tablets, generate believable analytical data from a range of instruments and write a convincing publication-ready manuscript with evidence of critical interpretation. The model achieved all this is less than 1 h. Moreover, the generated data were multi-modal in nature, including thermal analyses, vibrational spectroscopy and dissolution testing, demonstrating multi-disciplinary expertise in the LLM. One area in which the model failed, however, was in referencing to the literature. Since the generated experimental results appeared believable though, we suggest that LLMs could certainly play a role in scientific research but with human input, interpretation and data validation. We discuss the potential benefits and current bottlenecks for realising this ambition here.

Dynamic characteristics of scraper conveyor chain drive system under the impact condition of lump coal

Scraper conveyor is the most important transportation equipment in the comprehensive mining equipment, and the chain drive system is its core subsystem, its dynamic characteristics will significantly affect the efficiency of coal transportation in the comprehensive mining face. In this paper, the dynamic characteristics of chain drive system when impacted by falling coal are investigated by means of test. The impact test bench of scraper conveyor was set up to analyze the effects of chain speed, impact height and impact load mass on the dynamic characteristics of the chain drive system of scraper conveyor under the working conditions of unloaded and loaded. The results show that the longitudinal vibration of the scraper conveyor is most obvious when it is impacted by the falling coal, and the chain speed, impact height and impact load mass of the scraper conveyor all play an excitation role on the vibration of the chain drive system, and the vibration of the chain ring is the most intense in the chain drive system, and the loaded coal pile conveyed on the scraper conveyor plays an inhibiting role on the vibration of the chain drive system. This study can help to identify the location where the scraper conveyor fails first in the impact condition, so as to provide a basis for its structural design and improvement, which is of great significance for the stable operation and structural optimization of the scraper conveyor.

Reconstruction of Vocal Fold Medial Surface 3D Trajectories: Effects of Neuromuscular Stimulation and Airflow

INTRODUCTION

Analysis of medial surface dynamics of the vocal folds (VF) is critical to understanding voice production and treatment of voice disorders. We analyzed VF medial surface vibratory dynamics, evaluating the effects of airflow and nerve stimulation using 3D reconstruction and empirical eigenfunctions (EEF).

STUDY DESIGN

In vivo canine hemilarynx phonation.

METHODS

An in vivo canine hemilarynx was phonated while graded stimulation of the recurrent and superior laryngeal nerves (RLN and SLN) was performed. For each phonatory condition, vibratory cycles were 3D reconstructed from tattooed landmarks on the VF medial surface at low, medium, and high airflows. Parameters describing medial surface trajectory shape were calculated, and underlying patterns were emphasized using EEFs. Fundamental frequency and smoothed cepstral peak prominence (CPPS) were calculated from acoustic data.

RESULTS

Convex-hull area of landmark trajectories increased with increasing flow and decreasing nerve activation level. Trajectory shapes observed included circular, ellipsoid, bent, and figure-eight. They were more circular on the superior and anterior VF, and more elliptical and line-like on the inferior and posterior VF. The EEFs capturing synchronal opening and closing (EEF1) and alternating convergent/divergent (EEF2) glottis shapes were mostly unaffected by flow and nerve stimulation levels. CPPS increased with higher airflow except for low RLN activation and very dominant SLN stimulation.

CONCLUSION

We analyzed VF vibration as a function of neuromuscular stimulation and airflow levels. Oscillation patterns such as figure-eight and bent trajectories were linked to high nerve activation and flow. Further studies investigating longer sections of 3D reconstructed oscillations are needed.

LEVEL OF EVIDENCE

N/A, Basic Science Laryngoscope, 134:1249-1257, 2024.

Immediate and Short-term Effects of Straw Phonation in Air or Water on Vocal Fold Vibration and Supraglottic Activity of Adult Patients with Voice Disorders Visualized with Strobovideolaryngoscopy: A Pilot Study

Purpose The first purpose of this study was to investigate and compare the short-term effects after a semi-occluded vocal tract (SOVT) therapy session consisting of straw phonation (SP) in air or water on vocal fold vibration and supraglottic activity of adult patients with voice disorders, visualized with strobovideolaryngoscopy (SVL). The second purpose of this study was to investigate and compare immediate changes in the patients' vocal fold vibration and supraglottic activity during SP in air or water, visualized with SVL. Methods Twelve adult patients with voice disorders (eight women and four men, mean age 52 years) were assigned randomly to one of two study groups: SP in air or SP in water. Immediately before and after a therapy session of 15 min, participants underwent a rigid SVL to determine the short-term effects of the SP session. At the posttherapy examination, flexible SVL while performing SP was added to determine the effects occurring during SP. The visual-perceptual ratings were performed blindly and in random order by three laryngologists, using the Voice-Vibratory Assessment with Laryngeal Imaging rating form for stroboscopy. ResultsShort-term effects after SP: After the SP-in-air session, the supraglottic mediolateral compression decreased significantly. The SP-in-water session led to significantly increased left vibrational amplitude. Immediate effects during SP: During SP in air, a significantly increased left amplitude and mucosal wave, and significantly decreased mediolateral supraglottic activity, were found. SP in water tended to decrease the vibrational amplitude during performance of the task. A trend toward higher anteroposterior supraglottic compression was observed during both SP in air and water, being more prominent in the latter. Conclusion SP in air led to less false vocal fold adduction and consequently less hyperfunction. The small increment in anteroposterior supraglottic activity during SP in air and water might be related to epilarynx narrowing, an economic phenomenon associated with SOVT exercises. The effects on vibrational amplitude were rather ambiguous. The small reduction in amplitude during SP in water is expected to diminish vocal fold impact stress and therefore creates an ideal basis for voice therapy. The increment in amplitude and mucosal wave during SP in air might indicate insufficient supraglottic pressure to obtain the favorable effects of semi-occlusion. Whether or not the rise in amplitude after the SP-in-water session is due to voice efficiency or voice fatigue remains unknown. Future larger-scale investigation in subgroups of voice patients is needed to explore these hypotheses.

Modeling of free vibrations and resonant frequencies of simply-supported submerged horizontal plate

A theoretical approach was applied to study the vibration of simple-supported submerged horizontal plate. The derived analytical solution was used to determine natural frequencies for a horizontal plate vibrating in fluid. The investigations were conducted for a very wide range of material density and elasticity modulus covering all materials used in engineering practice. Analysis shows that plate vibration frequency decreases with increasing plate width and draft, and decreases with decreasing plate thickness. Moreover, the results show that a substantial effect on vibration of submerged plate has mass of water above plate. The results also show that plate vibration frequency decreases with increasing plate material density and decreases with decreasing elasticity modulus. The dominant factors affecting the vibration of the submerged plate are the plate width, the plate thickness, and elasticity modulus. For moderate and low values of elasticity modulus, vibration frequency is becoming lower than frequency of water waves. This is very important because wave frequencies overlap with the natural plate vibration frequencies, which may lead to resonance and failure of a structure. The problem is that the overlap of plate vibration frequencies and wave frequencies occurs for very wide range of wave and plate parameters. Laboratory experiments confirm theoretical results.

Single-trial EEG analysis reveals burst structure during photic driving

OBJECTIVE

Photic driving in the human visual cortex evoked by intermittent photic stimulation is usually characterized in averaged data by an ongoing oscillation showing frequency entrainment and resonance phenomena during the course of stimulation. We challenge this view of an ongoing oscillation by analyzing unaveraged data.

METHODS

64-channel EEGs were recorded during visual stimulation with light flashes at eight stimulation frequencies between 7.8 and 23 Hz for fourteen healthy volunteers. Time-frequency analyses were performed in averaged and unaveraged data.

RESULTS

While we find ongoing oscillations in the averaged data during intermittent photic stimulation, we find transient events (bursts) of activity in the unaveraged data. Both resonance and entrainment occur for the ongoing oscillations in the averaged data and the bursts in the unaveraged data.

CONCLUSIONS

We argue that the continuous oscillations in the averaged signal may be composed of brief, transient bursts in single trials. Our results can also explain previously observed amplitude fluctuations in averaged photic driving data.

SIGNIFICANCE

Single-trial analyses might consequently improve our understanding of resonance and entrainment phenomena in the brain.

Terahertz Liquid Biosensor Based on A Graphene Metasurface for Ultrasensitive Detection with A Quasi-Bound State in the Continuum

The concept of a quasi-bound state in a continuum (QBIC) has garnered significant attention in various fields such as sensing, communication, and optical switching. Within metasurfaces, QBICs offer a reliable platform that enables sensing capabilities through potent interactions between local electric fields and matter. Herein, a novel terahertz (THz) biosensor based on the integration of QBIC with graphene is reported, which enables multidimensional detection. The proposed biosensor is distinctive because of its ability to discern concentrations of ethanol and N-methylpyrrolidone in a wide range from 100% to 0%, by monitoring the changes in the resonance intensity and maximum wavelet coefficient. This approach demonstrates an excellent linear fit, which ensures robust quantitative analysis. The remarkable sensitivity of our biosensor enables it to detect minute changes in low-concentration solutions, with the lowest detection concentration value (LDCV) of 0.21 pg mL-1 . 2D wavelet coefficient intensity cards are effectively constructed through continuous wavelet transforms, which presents a more accurate approach for determining the concentration of the solution. Ultimately, the novel sensing platform offers a host of advantages, including heightened sensitivity and reusability. This pioneering approach establishes a new avenue for liquid-based terahertz biosensing.

Restraining vocal fold vertical motion reduces source-filter interaction in a two-mass model

Previous experimental studies suggested that restraining the vocal fold vertical motion may reduce the coupling strength between the voice source and vocal tract. In this study, the effects of vocal fold vertical motion on source-filter interaction were systematically examined in a two-dimensional two-mass model coupled to a compressible flow simulation. The results showed that when allowed to move vertically, the vocal folds exhibited subharmonic vibration due to entrainment to the first vocal tract acoustic resonance. Restraining the vertical motion suppressed this entrainment. This indicates that the vertical mobility of the vocal folds may play a role in regulating source-filter interaction.

Effects of Thyroarytenoid Activation Induced Vibratory Asymmetry on Voice Acoustics and Perception

INTRODUCTION

Asymmetry of vocal fold (VF) vibration is common in patients with voice complaints and also observed in 10% of normophonic individuals. Although thyroarytenoid (TA) muscle activation plays a crucial role in regulating VF vibration, how TA activation asymmetry relates to voice acoustics and perception is unclear. We evaluated the relationship between TA activation asymmetry and the resulting acoustics and perception.

METHODS

An in vivo canine model of phonation was used to create symmetric and increasingly asymmetric VF vibratory conditions via graded stimulation of bilateral TA muscles. Naïve listeners (n = 89) rated the perceptual quality of 100 unique voice samples using a visual sort-and-rate task. For each phonatory condition, cepstral peak prominence (CPP), harmonic amplitude (H1-H2), and root-mean-square (RMS) energy of the voice were measured. The relationships between these metrics, vibratory asymmetry, and perceptual ratings were evaluated.

RESULTS

Increasing levels of TA asymmetry resulted in declining listener preference. Furthermore, only severely asymmetric audio samples were perceptually distinguishable from symmetric and mildly asymmetric conditions. CPP was negatively correlated with TA asymmetry: voices produced with larger degrees of asymmetry were associated with lower CPP values. Listeners preferred audio samples with higher values of CPP, high RMS energy, and lower H1-H2 (less breathy).

CONCLUSION

Listeners are sensitive to changes in voice acoustics related to vibratory asymmetry. Although increasing vibratory asymmetry is correlated with decreased perceptual ratings, mild asymmetries are perceptually tolerated. This study contributes to our understanding of voice production and quality by identifying perceptually salient and clinically meaningful asymmetry.

LEVEL OF EVIDENCE

N/A (Basic Science Study) Laryngoscope, 134:1327-1332, 2024.

Investigation of Age and Gender Effects on the Middle Ear With Wideband Tympanometry in Adults

OBJECTIVES

Several studies have reported the effects of age and gender on the middle ear of adults using wideband acoustic immittance (WAI) that measures middle ear function over a range of frequencies rather than the traditional measures with a single probe tone. Although these results are often based on WAI measurements under ambient pressure, using WAI under varying ear-canal pressures (wideband tympanometry [WBT]) may be able to provide more information about age and gender effects on the middle ear. The aim of this study is to examine the effects of age and gender on the middle ear with WBT in three different age groups consisting of young, middle-aged, and older adults.

DESIGN

A total of 95 adults with normal middle ear function were assessed, including 32 young adults (16 men, 16 women, aged 20 to 39 years), 31 middle-aged adults (15 men, 16 women, aged 41 to 60 years), and 32 older adults (16 men, 16 women, aged 65 to 82 years). WBT measurements were performed from 226 to 8000 Hz using Interacoustics Titan. Energy absorbance data at tympanometric peak pressure (EA TPP ) and ambient pressure (EA AP ) at 1/3 octave frequencies, and resonance frequency (RF) data were analyzed according to age and gender variables.

RESULTS

Analysis results showed that the mean EA TPP was significantly higher from 500 to 794 Hz and at 5040 and 6350 Hz, and significantly lower from 1587 to 3175 Hz in older adults compared with young adults. The mean EA AP was significantly lower from 1587 to 3175 Hz, and significantly higher at 5040 and 6350 Hz in older adults compared with young adults. There was no significant difference in the mean EA TPP and mean EA AP at any frequency between young and middle-aged adults, and middle-aged and older adults. RF was significantly lower in older adults compared with young adults. In all age groups, men had higher mean EA TPP and mean EA AP at lower frequencies and lower mean EA TPP and mean EA AP at higher frequencies than women. Men had slightly lower RF than women in young and older adults, while men had significantly lower RF than women in middle-aged adults.

CONCLUSIONS

This study demonstrated that there are possible age and gender effects on the middle ear that may affect the mechanical transmission of sound. It may be useful to consider this finding in clinical evaluation in adults of different ages and genders, and to establish age- and gender-specific WBT norms in the adult population.

The effect of anthropogenic substrate-borne vibrations on locomotion of the fiddler crab Austruca lactea

The anthropogenic construction activities on the coasts, such as pile-driving, generate vibrations that propagate through the substrate. Such substrate-borne vibrations could potentially affect marine organisms inhabiting the benthic environments. However, there is a lack of documented studies on the effects of vibrations on benthic animals. To investigate whether anthropogenic substrate-borne vibrations such as pile-driving operation influence the fiddler crab, Austruca lactea, we measured their locomotion response under vibrations of 35, 120, 250, 500, and 750 Hz generated by a vibrator. We compared the locomotion of crabs between control and vibration-treatment groups using videography. The duration of movements was significantly lower under 120 Hz vibrations compared to the control. Moreover, crab velocity was significantly higher under vibrations of 120 Hz and 250 Hz compared to the control group. Our result suggests that A. lactea can detect low-frequency substrate-borne vibrations and experience stress, leading to increased energy consumption.

Does vibrotactile stimulation of the auricular vagus nerve enhance working memory? A behavioral and physiological investigation

BACKGROUND

Working memory is essential to a wide range of cognitive functions and activities. Transcutaneous auricular vagus nerve stimulation (taVNS) is a promising method to improve working memory performance. However, the feasibility and scalability of electrical stimulation are constrained by several limitations, such as auricular discomfort and inconsistent electrical contact.

OBJECTIVE

We aimed to develop a novel and practical method, vibrotactile taVNS, to improve working memory. Further, we investigated its effects on arousal, measured by skin conductance and pupil diameter.

METHOD

This study included 20 healthy participants. Behavioral response, skin conductance, and eye tracking data were concurrently recorded while the participants performed N-back tasks under three conditions: vibrotactile taVNS delivered to the cymba concha, earlobe (sham control), and no stimulation (baseline control).

RESULTS

In 4-back tasks, which demand maximal working memory capacity, active vibrotactile taVNS significantly improved the performance metric d' compared to the baseline but not to the sham. Moreover, we found that the reduction rate of d' with increasing task difficulty was significantly smaller during vibrotactile taVNS sessions than in both baseline and sham conditions. Arousal, measured as skin conductance and pupil diameter, declined over the course of the tasks. Vibrotactile taVNS rescued this arousal decline, leading to arousal levels corresponding to optimal working memory levels. Moreover, pupil diameter and skin conductance level were higher during high-cognitive-load tasks when vibrotactile taVNS was delivered to the concha compared to baseline and sham.

CONCLUSION

Our findings suggest that vibrotactile taVNS modulates the arousal pathway and could be a potential intervention for enhancing working memory.

Regional differences in cochlear nonlinearity across the basal organ of Corti of gerbil: Regional differences in cochlear nonlinearity

Auditory sensation is based in nanoscale vibration of the sensory tissue of the cochlea, the organ of Corti complex (OCC). Motion within the OCC is now observable due to optical coherence tomography. In a previous study (Cooper et al., 2018), the region that includes the electro-motile outer hair cells (OHC) and Deiters cells (DC) was observed to move with larger amplitude than the basilar membrane (BM) and surrounding regions and was termed the "hotspot." In addition to this quantitative distinction, the hotspot moved qualitatively differently than the BM, in that its motion scaled nonlinearly with stimulus level at all frequencies, evincing sub-BF activity. Sub-BF activity enhances non-BF motion; thus the frequency tuning of the OHC/DC region was reduced relative to the BM. In this work we further explore the motion of the gerbil basal OCC and find that regions that lack significant sub-BF activity include the BM, the medial and lateral OCC, and the reticular lamina (RL) region. The observation that the RL region does not move actively sub-BF (already observed in Cho and Puria 2022), suggests that hair cell stereocilia are not exposed to sub-BF activity in the cochlear base. The observation that the lateral and RL regions move approximately linearly sub-BF indicates that linear forces dominate non-linear OHC-based forces on these components at sub-BF frequencies. A complex difference analysis was performed to reveal the internal motion of the OHC/DC region and showed that amplitude structure and phase shifts in the directly measured OHC/DC motion emerge due to the internal OHC/DC motion destructively interfering with BM motion.

Flow-induced high frequency vascular wall vibrations in an arteriovenous fistula: a specific stimulus for stenosis development?

Hemodialysis is the lifeline for nearly three million end stage renal disease patients worldwide. Native arteriovenous fistula (AVF) is the preferred vascular access, but 40% fail within 1 year. We recently demonstrated that AVFs harbour transitional flows and the goal of the present study was to investigate whether the associated high-frequency pressure fluctuations could promote vibrations within the vascular wall. We acquired MRI images and flow rates immediately after surgery in one patient and generated a 3D patient-specific model. High-fidelity fluid structure interaction simulations revealed the presence of wall vibrations in distinct frequency bands up to 200 Hz and amplitude of 200 μm. A sensitivity analysis to assess the impact of flow rates, and vascular wall stiffness and thickness, changes that typically occur during AVF maturation, confirmed the robustness of the results. Interestingly, the vibrations were always predominant at the anastomosis floor and on the inner venous side, which correlates with typical stenotic regions. As studies seeking to correlate aberrant stresses and vascular remodelling have been largely inconclusive, the focal colocalization between vibrations and stenosis may suggest an unknown mechanobiological process between high-frequency mechanical stresses within the vascular wall and adverse vascular remodelling.

Vibrational Study of the Inward Proton Pump Xenorhodopsin NsXeR: Switch Order Determines Vectoriality

Common proton pumps, e.g. HsBR and PR, transport protons out of the cell. Xenorhodopsins (XeR) were the first discovered microbial rhodopsins which come as natural inward proton pumps. In this work we combine steady-state (cryo-)FTIR and Raman spectroscopy with time-resolved IR and UV/Vis measurements to roadmap the inward proton transport of NsXeR and pinpoint the most important mechanistic features. Through the assignment of characteristic bands of the protein backbone, the retinal chromophore, the retinal Schiff base and D220, we could follow the switching processes for proton accessibility in accordance with the isomerization / switch / transfer model. The corresponding transient IR signatures suggest that the initial assignment of D220 as the proton acceptor needs to be questioned due to the temporal mismatch of the Schiff base and D220 protonation steps. The switching events in the K-L and MCP-MEC transitions are finely tuned by changes of the protein backbone and rearrangements of the Schiff base. This finely tuned mechanism is disrupted at cryogenic temperatures, being reflected in the replacement of the previously reported long-lived intermediate GS* by an actual redshifted (O-like) intermediate.

How to objectively measure snoring: a systematic review

PURPOSE

Snoring is the most common symptom of obstructive sleep apnea. Various objective methods of measuring snoring are available, and even if the measurement is performed the same way, communication is difficult because there are no common reference values between the researcher and clinician with regard to intensity and frequency, among other variables. In other words, no consensus regarding objective measurement has been reached. This study aimed to review the literature related to the objective measurement of snoring, such as measurement devices, definitions, and device locations.

METHODS

A literature search based on the PubMed, Cochrane, and Embase databases was conducted from the date of inception to April 5, 2023. Twenty-nine articles were included in this study. Articles that mentioned only the equipment used for measurement and did not include individual details were excluded from the study.

RESULTS

Three representative methods for measuring snoring emerged. These include (1) a microphone, which measures snoring sound; (2) piezoelectric sensor, which measures snoring vibration; and (3) nasal transducer, which measures airflow. In addition, recent attempts have been made to measure snoring using smartphones and applications.

CONCLUSION

Numerous studies have investigated both obstructive sleep apnea and snoring. However, the objective methods of measuring snoring and snoring-related concepts vary across studies. Consensus in the academic and clinical communities on how to measure and define snoring is required.

Electrostimulation of the white matter of the posterior insula and medial operculum: perception of vibrations, heat, and pain

ABSTRACT

This study aimed to characterize the sensory responses observed when electrically stimulating the white matter surrounding the posterior insula and medial operculum (PIMO). We reviewed patients operated on under awake conditions for a glioma located in the temporoparietal junction. Patients' perceptions were retrieved from operative reports. Stimulation points were registered in the Montreal Neurological Institute template. A total of 12 stimulation points in 8 patients were analyzed. Painful sensations in the contralateral leg were reported (5 sites in 5 patients) when stimulating the white matter close to the parcel OP2/3 of the Glasser atlas. Pain had diverse qualities: burning, tingling, crushing, or electric shock. More laterally, in the white matter of OP1, pain and heat sensations in the upper part of the body were described (5 sites in 2 patients). Intermingled with these sites, vibration sensations were also reported (3 sites in 2 patients). Based on the tractograms of 44 subjects from the Human Connectome Project data set, we built a template of the pathways linking the thalamus to OP2/3 and OP1. Pain sites were located in the thalamo-OP2/3 and thalamo-OP1 tracts. Heat sites were located in the thalamo-OP1 tract. In the 227 awake surgeries performed for a tumor located outside of the PIMO region, no patients ever reported pain or heat sensations when stimulating the white matter. Thus, we propose that the thalamo-PIMO connections constitute the main cortical inputs for nociception and thermoception and emphasize that preserving these fibers is of utmost importance to prevent the postoperative onset of a debilitating insulo-opercular pain syndrome.

Iminothioindoxyl Donors with Exceptionally High Cross Section for Protein Vibrational Energy Transfer

Various protein functions are related to vibrational energy transfer (VET) as an important mechanism. The underlying transfer pathways can be experimentally followed by ultrafast Vis-pump/IR-probe spectroscopy with a donor-sensor pair of non-canonical amino acids (ncAAs) incorporated in a protein. However, so far only one donor ncAA, azulenylalanine (AzAla), exists, which suffers from a comparably low Vis extinction coefficient. Here, we introduce two novel donor ncAAs based on an iminothioindoxyl (ITI) chromophore. The dimethylamino-ITI (DMA-ITI) and julolidine-ITI (J-ITI) moieties overcome the limitation of AzAla with a 50 times higher Vis extinction coefficient. While ITI moieties are known for ultrafast photoswitching, DMA-ITI and J-ITI exclusively form a hot ground state on the sub-ps timescale instead, which is essential for their usage as vibrational energy donor. In VET measurements of donor-sensor dipeptides we investigate the performance of the new donors. We observe 20 times larger signals compared to the established AzAla donor, which opens unprecedented possibilities for the study of VET in proteins.

Moss bugs shed light on the evolution of complex bioacoustic systems

Vibroacoustic signalling is one of the dominant strategies of animal communication, especially in small invertebrates. Among insects, the order Hemiptera displays a staggering diversity of vibroacoustic organs and is renowned for possessing biomechanically complex elastic recoil devices such as tymbals and snapping organs that enable robust vibrational communication. However, our understanding of the evolution of hemipteran elastic recoil devices is hindered by the absence of relevant data in the phylogenetically important group known as moss bugs (Coleorrhyncha), which produce substrate-borne vibrations through an unknown mechanism. In the present work, we reveal the functional morphology of the moss bug vibrational mechanism and study its presence across Coleorrhyncha and in extinct fossilised relatives. We incorporate the anatomical features of the moss bug vibrational mechanism in a phylogeny of Hemiptera, which supports either a sister-group relationship to Heteroptera, or a sister-group relationship with the Auchenorrhyncha. Regardless of topology, we propose that simple abdominal vibration was present at the root of Euhemiptera, and arose 350 million years ago, suggesting that this mode of signalling is among the most ancient in the animal kingdom. Therefore, the most parsimonious explanation for the origins of complex elastic recoil devices is that they represent secondary developments that arose exclusively in the Auchenorrhyncha.

Phase-shifting optothermal microscopy enables live-cell mid-infrared hyperspectral imaging of large cell populations at high confluency

Rapid live-cell hyperspectral imaging at large fields of view (FOVs) and high cell confluency remains challenging for conventional vibrational spectroscopy-based microscopy technologies. At the same time, imaging at high cell confluency and large FOVs is important for proper cell function and statistical significance of measurements, respectively. Here, we introduce phase-shifting mid-infrared optothermal microscopy (PSOM), which interprets molecular-vibrational information as the optical path difference induced by mid-infrared absorption and can take snapshot vibrational images over broad excitation areas at high live-cell confluency. By means of phase-shifting, PSOM suppresses noise to a quarter of current optothermal microscopy modalities to allow capturing live-cell vibrational images at FOVs up to 50 times larger than state of the art. PSOM also reduces illumination power flux density (PFD) down to four orders of magnitude lower than other conventional vibrational microscopy methods, such as coherent anti-Stokes Raman scattering (CARS), thus considerably decreasing the risk of cell photodamage.

The feasibility of MR elastography with transpelvic vibration for localization of focal prostate lesion

We aimed to evaluate the feasibility of MR elastography (MRE) using a transpelvic approach. Thirty-one patients who underwent prostate MRE and had a pathological diagnosis were included in this study. MRE was obtained using a passive driver placed at the umbilicus and iliac crests. The shear stiffness, clinical data, and conventional imaging findings of prostate cancer and benign prostatic hyperplasia (BPH) were compared. Inter-reader agreements were evaluated using the intraclass coefficient class (ICC). Prostate MRE was successfully performed for all patients (100% technical success rate). Nineteen cancer and 10 BPH lesions were visualized on MRE. The mean shear stiffness of cancer was significantly higher than that of BPH (5.99 ± 1.46 kPa vs. 4.67 ± 1.54 kPa, p = 0.045). One cancer was detected on MRE but not on conventional sequences. Six tiny cancer lesions were not visualized on MRE. The mean size of cancers that were not detected on MRE was smaller than that of cancers that were visible on MRE (0.8 ± 0.3 cm vs. 2.3 ± 1.8 cm, p = 0.001). The inter-reader agreement for interpreting MRE was excellent (ICC = 0.95). Prostate MRE with transpelvic vibration is feasible without intracavitary actuators. Transpelvic prostate MRE is reliable for detecting focal lesions, including clinically significant prostate cancer and BPH.