bluuebunny/crossref_metadata_2025 huggingface dataset:
A diffraction approach to assess the elastic properties of a nylon string
Authors: Muñoz-Pérez Francisco M , Garmendía-Martínez Adrián , Castro-Palacio Juan C , Ferrando Vicente , Monsoriu Juan A
Published: February 2024

Young’s modulus of a nylon string has been determined experimentally by combining elasticity theory and wave optics. A diffraction experiment was setup to determine the change in string diameter for different tensile forces, applied by means of hanging weights. A linear elasticity model was used to calculate Young’s modulus. We provide a simple method, which could be used as the basis of an experiment for the introductory university level.
Computational modelling and experimental investigation of micro-electrochemical discharge machining by controlling the electrolyte temperature
Authors: Bahar Dil , Dvivedi Akshay , Kumar Pradeep
Published: February 2024

Glass vias are emerging as a favourable option for radiofrequency-based micro-electromechanical system packaging. For the micromachining of glass, electrochemical discharge machining (ECDM) could be the most suitable technique if issues pertaining to the process stability are addressed thoroughly. The electrolyte temperature has immense influence on the viscosity and conductivity of the electrolyte, which percolate the stability of the ECDM process. Therefore, this article investigates the effects of the electrolyte temperature and applied voltage on the performance characteristics of ECDM for the micromachining of borosilicate glass. The machining rate (MR) and hole overcut (HOC) of the machined microholes are considered as performance characteristics. A 3D thermal-based finite element model (FEM) was developed for the thermal analysis in the machining zone. In the thermal analysis, the heat flux by thermal discharge was assumed to have Gaussian distribution, and accordingly, temperature profiles in the thermal zone were analyzed by controlling the electrolyte temperature and voltage at various levels. Further processing of temperature profiles in the thermal zone was utilized in the estimation of MR and HOC. Electrostatic-based FEM was utilized to assess the intensity of the electric field in the proximity of the tool electrode to analyze the probable locations of thermal discharge and its impact on the geometrical characteristics of the machined microholes. The simulation outcomes were validated experimentally, and show good agreement. A field emission electron microscope with energy dispersive spectroscopy was used for the characterization of the machined surface to observe the effect of the electrolyte temperature.
An integration scheme of simultaneous cycle slips determination combining improved geometry-free combination and TDCP model for undifferenced GNSS data
Authors: Li Shuaishuai , Feng Wei , Huang Dingfa
Published: February 2024

Fast and reliable cycle slip determination can ensure successive ambiguity resolution and precise positioning. Generally, it is not difficult to determine big cycle slips using the linear combination of observations, for instance, the geometry-free (GF) combination and the Hatch–Melbourne–Wübbena (HMW) combination. However, the participation of pseudorange observations may fail to identify small cycle slips. This contribution proposes an integration scheme combining the improved geometry-free (IGF) combination and time-difference carrier phase (TDCP) model to determine simultaneous cycle slips for undifferenced kinematic data. The IGF combination, which is improved from the modified geometry-free (MGF) combination and utilizes the Gauss floor function to take the decimal part of GF, can directly determine small cycle slips on a specific frequency. The TDCP model is used to estimate the differences of position and clock error between adjacent epochs by least-square adjustment using clean phase observations, and repair the remaining cycle slips by the predicted TDCP measurements obtained from the predetermined parameters. The proposed method is tested against 1 Hz kinematic dataset with simulation and highway dataset with real cycle slips. In the simulation test, all cycle slips can be correctly repaired by IGF for L1/L5, E1/E5 and E1/E5a. These combinations are unavailable for MGF. Compared to the HMW-GF method, the repair success rate of IGF improves from 96.80% to 99.16%, and the number of incorrect cases reduces from 9650 to 2535. The IGF-TDCP integration scheme can further improve the performance of IGF, whose repair success rate is more than 99.97% and incorrect cases are 38. The highway test shows that the proposed method effectively processes simultaneous cycle slips on more than half of the tracking satellites caused by the overpasses, even in the case of simultaneous 3 second data gaps on 5 satellites of 6 tracking satellites.
Chromatic confocal coherence scanning interferometry with speed-variable scanning method to measure large-depth step
Authors: Zhao Yulu , Chang Songtao , Zhang Yi , Xu Feifan , Xia Haojie
Published: February 2024

Coherence scanning interferometry (CSI) is a crucial measurement technique for achieving non-contact, rapid, and high-precision measurements. However, when applied to large-depth steps, CSI encounters challenges related to prolonged measurement times and suboptimal signal utilization. This paper introduces a hybrid CSI system that integrates the chromatic confocal technique (CC-CSI). The confocal spectral signal peak facilitates the rapid determination of the coherence area, allowing the scanning process to be divided into two phases. The signal collection is limited within the coherence area at a lower scanning speed, while in other positions, the scanning speed is increased. This speed-variable scanning technique significantly augments measurement efficiency. The CC-CSI system with the speed-variable scanning method demonstrated a significant enhancement in measurement time compared to conventional CSI under identical experimental conditions. The measured step heights were 100 μm, 200 μm, and 300 μm. Standard deviations of less than 0.3 μm were observed in 10 consecutive measurements. In addition, the proposed CC-CSI system demonstrated the capability to profile the groove structure.
An elementary method for calculating the duration of motion of a block with mass attached to the end of a spring under the influence of kinetic friction
Authors: Poulakis Michail , Malamou Anna , Kontomaris Stylianos Vasileios
Published: February 2024

Calculating time intervals in motions with non-constant acceleration is a challenging task. In most cases, advanced mathematical tools are required. Therefore, these topics are usually not suitable for presentation at the high school level. In this paper, the case of the motion of a block of mass attached to the end of a linear spring on a rough surface is revisited. The goal is to find an elementary method for calculating the time interval required to cover a distance between two arbitrary positions suitable for teaching at the high school level. To accomplish this goal, a mathematically ‘equivalent problem’ involving the combination of simple harmonic motions between two different equilibrium positions is considered. It effectively conveys that with this approach, the calculation of time intervals relies solely on simple trigonometry. In addition, students can draw interesting conclusions, such as the linear decay of the oscillation’s amplitude and the independence of the period from the oscillation’s amplitude.
Effect of the rising edge of ultrashort laser pulse on the target normal sheath acceleration of ions
Authors: Psikal J
Published: February 2024

Laser-driven ion acceleration is theoretically/numerically mostly studied with the assumption of an idealised main ultrashort pulse of the Gaussian temporal shape, where nanosecond/multi-picosecond pedestals and short prepulses preceding the main pulse can be incorporated in the form of modifications in the initial density profile of irradiated ionised targets. This paper shows that the relatively slowly rising edge (also called picosecond ramp) of the main ultrashort pulse, usually neglected in previous studies, can substantially change the efficiency of the target normal sheath acceleration of ions depending on the laser intensity. The rising edge can enhance ion acceleration at mildly relativistic laser intensities, but increases the divergence and reduces the cutoff energy of accelerated ions at highly relativistic intensities relevant to petawatt lasers.
Hole-edge crack monitoring in attachment lug with large bolt hole based on guided wave and circular piezoelectric sensor array
Authors: Shi Liming , Deng Bin , Xu Qiyun , Chen Jian , Qiu Lei
Published: February 2024

The crack damage monitoring of aircraft structures is very significant for ensuring aircraft safety, reducing maintenance costs and extending service life. Due to the extreme service environment, the attachment lug is prone to initiate crack damage at the hole edge, which leads to crack propagation and fracture failure. Structural health monitoring technology based on piezoelectric guided wave has been widely studied, promoting the development of crack monitoring. However, at present, research on hole-edge crack damage monitoring of attachment lugs still needs to be further carried out. It is difficult to monitor small cracks at the initial stage of crack propagation, and the accuracy of crack monitoring needs to be improved. By focusing on the accuracy of the crack monitoring in the attachment lug, a crack damage monitoring method based on the circular piezoelectric sensor array is proposed in this paper. Combined with damage alarming and localization imaging, this method comprehensively evaluates the hole-edge crack damage monitoring situation and improves the monitoring effect. The method is verified by an experiment in attachment lug, and this verification includes small crack monitoring and crack propagation monitoring. The experimental results demonstrate that this method can achieve correct damage alarming results, and the maximum localization error of crack damage is only 3.02 mm, which provides a research idea for the accurate monitoring of crack damage at the hole edge.
A proof-of-concept Bitter-like HTS electromagnet fabricated from a silver-infiltrated (RE)BCO ceramic bulk
Authors: Taylor R W , Weijers H W , Ainslie M D , Congreve J V J , Durrell J H , Badcock R A , Bumby C W
Published: February 2024

A novel concept for a compact high-field magnet coil is introduced. This is based on stacking slit annular discs cut from bulk rare-earth barium cuprate ((RE)BCO) ceramic in a Bitter-like architecture. Finite-element modelling shows that a small 20 turn stack (with a total coil volume of

<

20 cm3) is capable of generating a central bore magnetic field of

>

2 T at 77 K and

>

20 T at 30 K. Unlike resistive Bitter magnets, the high-temperature superconducting (HTS) Bitter stack exhibits significant non-linear field behaviour during current ramping, caused by current filling proceeding from the inner radius outwards in each HTS layer. Practical proof-of-concept for this architecture was then demonstrated through fabricating an uninsulated four-turn prototype coil stack and operating this at 77 K. A maximum central field of 0.382 T was measured at 1.2 kA, with an accompanying 6.1 W of internal heat dissipation within the coil. Strong magnetic hysteresis behaviour was observed within the prototype coil, with ≈30% of the maximum central field still remaining trapped 45 min after the current had been removed. The coil was thermally stable during a 15 min hold at 1 kA, and survived thermal cycling to room temperature without noticeable deterioration in performance. A final test-to-destruction of the coil showed that the limiting weak point in the stack was growth-sector boundaries present in the original (RE)BCO bulk.
Quantum-state engineering in cavity magnomechanics formed by two-dimensional magnetic materials
Authors: Yang Chun-Jie , Tong QingJun , An Jun-Hong
Published: February 2024

Cavity magnomechanics has become an ideal platform to explore macroscopic quantum effects. Bringing together magnons, phonons, and photons in a system, it opens many opportunities for quantum technologies. It was conventionally realized by an yttrium iron garnet, which exhibits a parametric magnon–phonon coupling

m
ˆ

†

m
ˆ

(

b
ˆ

†

+

b
ˆ

)

, with

m
ˆ

and

b
ˆ

being the magnon and phonon modes. Inspired by the recent realization of two-dimensional (2D) magnets, we propose a cavity magnomechanical system using a 2D magnetic material with both optical and magnetic drivings. It features the coexisting photon–phonon radiation-pressure coupling and quadratic magnon–phonon coupling

m
ˆ

†

m
ˆ

(

b
ˆ

†

+

b
ˆ

)
2

induced by the magnetostrictive interaction. A stable squeezing of the phonon and bi- and tri-partite entanglements among the three modes are generated in the regimes with a suppressed phonon number. Compared with previous schemes, ours does not require any extra nonlinear interaction and reservoir engineering and is robust against the thermal fluctuation. Enriching the realization of cavity magnomechanics, our system exhibits its superiority in quantum-state engineering due to the versatile interactions enabled by its 2D feature.
The role of RF-induced E×B flows in the mitigation of scrape-off-layer convective transport during ion cyclotron resonance heating
Authors: Diab R. , Decristoforo G. , Ahmed S. , Baek S.G. , Lin Y. , Marmar E. , Terry J.L. , Wukitch S.J.
Published: February 2024

While multiple experiments have reported a decrease in intermittent fluctuations in the far Scrape-Off-Layer (SOL) during ion cyclotron resonance heating (Antar et al 2010 Phys. Rev. Lett.
105 165001, Li et al 2022 Nucl. Eng. Technol.
54 207–19, Antar et al 2012 Nucl. Fusion
52 103005), the physical mechanism behind this observation has not been fully established yet. In this work, we demonstrate, for the first time, a direct correlation between the amplitude of RF-induced E×B flows and turbulence suppression in the far SOL. Using the Gas Puff Imaging (GPI) diagnostic on Alcator C-Mod, we show again that Ion Cyclotron Range of Frequencies can significantly alter the flow in the SOL and introduce a shear layer in regions magnetically connected close to the antenna (Cziegler et al 2012 Plasma Phys. Control. Fusion
54 105019). With the 4-strap field-aligned antenna operated in dipole phasing, the ratio of the power coupled by the central two straps to the power coupled by the outer two straps was varied. The resulting RF-induced radial electric field magnitude thus varied, and we show that the impact on the far SOL turbulence correlates with the modified E×B velocity. We then apply a newly-developed blob tracking algorithm (Han et al 2022 Sci. Rep.
12 18142) to higher-resolution GPI videos in order to directly observe the process of blob shearing by RF-induced E×B flows. We show that the radially sheared poloidal flows act as a transport barrier by stretching, stopping, and destroying filaments, which is consistent with the observed difference in turbulence statistics.
Molecular dynamics simulations and experimental studies on low-temperature growth of GaN
Authors: Li Xiang , Luo Yi , Wang Lai , Wang Jian , Hao Zhibiao , Sun Changzheng , Han Yanjun , Xiong Bing , Li Hongtao
Published: February 2024

Growth mechanisms of (0001) wurtzite GaN films at low temperature are investigated by molecular dynamics simulations and experiments. The crystallization properties of GaN films deteriorate dramatically at low temperature due to the limited energy available for atomic surface migration and incorporation into the perfect lattice sites. In our simulation, growth interruption stage is periodically introduced and the as-deposited GaN films are treated with energy-carrying argon ions at this stage. The surface atoms located at the weak binding sites can acquire energy from the argon ions for secondary migration and incorporation into the perfect lattice sites. As a result, the crystallization properties of GaN films are significantly improved. GaN films are experimentally grown on sputtered AlN/sapphire substrates at 600 °C via inductively coupled plasma metal organic chemical vapor deposition along with periodic argon plasma treatment. The as-deposited film acquires energy from the plasma, leading to significant improvement of the crystalline properties. The surface morphology of the GaN film demonstrates a noticeable smoothing effect, with an evident increase in grain size from submicron to micron level. Additionally, GaN film with the optimized surface morphology exhibits high c-axis and in-plane orientations, and the full width half maximums of (002) and (102) x-ray diffraction rocking curves are 0.25° and 0.32°, respectively. These results provide effective guidance for the growth of GaN films at low temperature.
Corrigendum to “Non-linear singularity formation for circular vortex sheets”
Authors: Murray Ryan , Wilcox Galen
Published: February 2024

This paper serves as a short corrigendum, describing an error in the derivation of the linearized equation. The main theorems remain correct, but they are based upon an incorrect linearization of the Birkhoff-Rott equation and hence are not directly applicable to the original physical problem.
Anti-herbivory defences delivered by Epichloë fungal endophytes: a quantitative review of alkaloid concentration variation among hosts and plant parts
Authors: Realini Florencia M , Escobedo Víctor M , Ueno Andrea C , Bastías Daniel A , Schardl Christopher L , Biganzoli Fernando , Gundel Pedro E
Published: February 2024

Background and Aims

In the subfamily Poöideae (Poaceae), certain grass species possess anti-herbivore alkaloids synthesized by fungal endophytes that belong to the genus Epichloë (Clavicipitaceae). The protective role of these symbiotic endophytes can vary, depending on alkaloid concentrations within specific plant–endophyte associations and plant parts.

Methods

We conducted a literature review to identify articles containing alkaloid concentration data for various plant parts in six important pasture species, Lolium arundinaceum, Lolium perenne, Lolium pratense, Lolium multiflorum|Lolium rigidum and Festuca rubra, associated with their common endophytes. We considered the alkaloids lolines (1-aminopyrrolizidines), peramine (pyrrolopyrazines), ergovaline (ergot alkaloids) and lolitrem B (indole-diterpenes). While all these alkaloids have shown bioactivity against insect herbivores, ergovaline and lolitrem B are harmful for mammals.

Key Results

Loline alkaloid levels were higher in the perennial grasses L. pratense and L. arundinaceum compared to the annual species L. multiflorum and L. rigidum, and higher in reproductive tissues than in vegetative structures. This is probably due to the greater biomass accumulation in perennial species that can result in higher endophyte mycelial biomass. Peramine concentrations were higher in L. perenne than in L. arundinaceum and not affected by plant part. This can be attributed to the high within-plant mobility of peramine. Ergovaline and lolitrem B, both hydrophobic compounds, were associated with plant parts where fungal mycelium is usually present, and their concentrations were higher in plant reproductive tissues. Only loline alkaloid data were sufficient for below-ground tissue analyses and concentrations were lower than in above-ground parts.

Conclusions

Our study provides a comprehensive synthesis of fungal alkaloid variation across host grasses and plant parts, essential for understanding the endophyte-conferred defence extent. The patterns can be understood by considering endophyte growth within the plant and alkaloid mobility. Our study identifies research gaps, including the limited documentation of alkaloid presence in roots and the need to investigate the influence of different environmental conditions.
Establishment of new transurethral catheterization methods for male mice
Authors: Duan Xi , Chen Zhibin , Zhan Zhean , Li Langhui , Lei Xianying , Long Yang , Xie Xiang , Chen Huan
Published: February 2024

Transurethral catheterization in mice is multifaceted, serving essential functions such as perfusion and drug delivery, and is critical in the development of various urological animal disease models. The complex anatomy of the male mouse urethra presents significant challenges in transurethral catheterization, leading to a predominance of research focused on female specimens. This bias limits the utilization of male mice in lower urinary tract disease studies. Our research aims to develop new reliable methods for transurethral catheterization in adult male mice, thereby expanding their use in relevant disease research. Experiments were conducted on adult male C57BL/6J mice. Utilizing a PE10 catheter measuring 4.5–5 cm in length, the catheter was inserted into the bladder via the mouse’s urethra under anesthesia. The intubation technique entailed regulating the insertion force, ensuring the catheter's lubrication, using a trocar catheter, modifying the catheter’s trajectory, and accommodating the curvature of the bladder neck. Post-catheter insertion, ultrasound imaging was employed to confirm the catheter's accurate positioning within the bladder. Subsequent to catheterization, the bladder was perfused using trypan blue. This method was further validated through its successful application in establishing an acute urinary retention (AUR) model, where the mouse bladder was infused with saline to a pressure of 50 or 80 cm H2O, maintained steadily for 30 min. A thorough morphological assessment of the mouse bladder was conducted after the infusion. Our study successfully pioneered methods for transurethral catheterization in male mice. This technique not only facilitates precise transurethral catheterization but also proves applicable to male mouse models for lower urinary tract diseases, such as AUR.
Spike ripples localize the epileptogenic zone best: an international intracranial study
Authors: Shi Wen , Shaw Dana , Walsh Katherine G , Han Xue , Eden Uri T , Richardson Robert M , Gliske Stephen V , Jacobs Julia , Brinkmann Benjamin H , Worrell Gregory A , Stacey William C , Frauscher Birgit , Thomas John , Kramer Mark A , Chu Catherine J
Published: February 2024

We evaluated whether spike ripples, the combination of epileptiform spikes and ripples, provide a reliable and improved biomarker for the epileptogenic zone compared with other leading interictal biomarkers in a multicentre, international study.

We first validated an automated spike ripple detector on intracranial EEG recordings. We then applied this detector to subjects from four centres who subsequently underwent surgical resection with known 1-year outcomes. We evaluated the spike ripple rate in subjects cured after resection [International League Against Epilepsy Class 1 outcome (ILAE 1)] and those with persistent seizures (ILAE 2–6) across sites and recording types. We also evaluated available interictal biomarkers: spike, spike-gamma, wideband high frequency oscillation (HFO, 80–500 Hz), ripple (80–250 Hz) and fast ripple (250–500 Hz) rates using previously validated automated detectors. The proportion of resected events was computed and compared across subject outcomes and biomarkers.

Overall, 109 subjects were included. Most spike ripples were removed in subjects with ILAE 1 outcome (P < 0.001), and this was qualitatively observed across all sites and for depth and subdural electrodes (P < 0.001 and P < 0.001, respectively). Among ILAE 1 subjects, the mean spike ripple rate was higher in the resected volume (0.66/min) than in the non-removed tissue (0.08/min, P < 0.001). A higher proportion of spike ripples were removed in subjects with ILAE 1 outcomes compared with ILAE 2–6 outcomes (P = 0.06). Among ILAE 1 subjects, the proportion of spike ripples removed was higher than the proportion of spikes (P < 0.001), spike-gamma (P < 0.001), wideband HFOs (P < 0.001), ripples (P = 0.009) and fast ripples (P = 0.009) removed. At the individual level, more subjects with ILAE 1 outcomes had the majority of spike ripples removed (79%, 38/48) than spikes (69%, P = 0.12), spike-gamma (69%, P = 0.12), wideband HFOs (63%, P = 0.03), ripples (45%, P = 0.01) or fast ripples (36%, P < 0.001) removed.

Thus, in this large, multicentre cohort, when surgical resection was successful, the majority of spike ripples were removed. Furthermore, automatically detected spike ripples localize the epileptogenic tissue better than spikes, spike-gamma, wideband HFOs, ripples and fast ripples.
Male dingo urinary scents code for age class and wild dingoes respond to this information
Authors: Walker Benjamin J J , Letnic Mike , Bucknall Martin P , Watson Lyn , Jordan Neil R
Published: February 2024

Chemical information in canid urine has been implicated in territoriality and influences the spacing of individuals. We identified the key volatile organic compound (VOC) components in dingo (Canis lupus dingo) urine and investigated the potential role of scents in territorial spacing. VOC analysis, using headspace gas chromatography–mass spectrometry (GC–MS), demonstrated that the information in fresh urine from adult male dingoes was sufficient to allow statistical classification into age categories. Discriminant function analyses demonstrated that the relative amounts or combinations of key VOCs from pre-prime (3–4 years), prime (5–9 years), and post-prime (≥10 years) males varied between these age categories, and that scents exposed to the environment for 4 (but not 33) days could still be classified to age categories. Further, a field experiment showed that dingoes spent less time in the vicinity of prime male dingo scents than other scents. Collectively, these results indicate that age-related scent differences may be discriminable by dingoes. Previous authors have suggested the potential to use scent as a management tool for wild canids by creating an artificial territorial boundary/barrier. Our results suggest that identifying the specific signals in prime-age male scents could facilitate the development of scent-based tools for non-lethal management.
Serial Mass Screening for Tuberculosis Among Incarcerated Persons in Brazil
Authors: Pivetta de Araujo Rafaele Carla , Martinez Leonardo , da Silva Santos Andrea , Ferreira Lemos Everton , Dias de Oliveira Roberto , Croda Mariana , Porto Batestin Silva Dâmaris , Lemes Isabella Beatriz Gonçalves , Cunha Eunice Atsuko Totumi , Gonçalves Thais Oliveira , Pereira dos Santos Paulo Cesar , Oliveira da Silva Bruna , Cavalheiro Maymone Gonçalves Crhistinne , Andrews Jason , Croda Julio
Published: February 2024

Background

An active search for tuberculosis cases through mass screening is widely described as a tool to improve case detection in hyperendemic settings. However, its effectiveness in high-risk populations, such as incarcerated people, is debated.

Methods

Between 2017 and 2021, 3 rounds of mass screening were carried out in 3 Brazilian prisons. Social and health questionnaires, chest X-rays, and Xpert MTB/RIF were performed.

Results

More than 80% of the prison population was screened. Overall, 684 cases of pulmonary tuberculosis were diagnosed. Prevalence across screening rounds was not statistically different. Among incarcerated persons with symptoms, the overall prevalence of tuberculosis per 100 000 persons was 8497 (95% confidence interval [CI], 7346–9811), 11 115 (95% CI, 9471–13 082), and 7957 (95% CI, 6380–9882) in screening rounds 1, 2, and 3, respectively. Similar to our overall results, there were no statistical differences between screening rounds and within individual prisons. We found no statistical differences in Computer-Aided Detection for TB version 5 scores across screening rounds among people with tuberculosis—the median scores in rounds 1, 2, and 3 were 82 (interquartile range [IQR], 63–97), 77 (IQR, 60–94), and 81 (IQR, 67–92), respectively.

Conclusions

In this environment with hyperendemic rates of tuberculosis, 3 rounds of mass screening did not reduce the overall tuberculosis burden. In prisons, where a substantial number of tuberculosis cases is undiagnosed annually, a range of complementary interventions and more frequent tuberculosis cases screening may be required.
Randomized Multicenter Trial for the Validation of an Easy-to-Administer Algorithm to Define Penicillin Allergy Status in Sexually Transmitted Infection Clinic Outpatients
Authors: Lillis Rebecca A , Barbee Lindley A , McNeil Candice J , Newman Lori , Fortenberry J Dennis , Alvarez-Arango Santiago , Zenilman Jonathan M
Published: February 2024

Background

Approximately 15% of patients in sexually transmitted infection (STI) clinics report penicillin allergies, complicating treatment for syphilis and gonorrhea. Nonetheless, >90% do not have a penicillin allergy when evaluated. We developed and validated an algorithm to define which patients reporting penicillin allergy can be safely treated at STI clinics with these drugs.

Methods

Randomized controlled trial to assess feasibility and safety of penicillin allergy evaluations in STI clinics. Participants with reported penicillin allergy answered an expert-developed questionnaire to stratify risk. Low-risk participants underwent penicillin skin testing (PST) followed by amoxicillin 250 mg challenge or a graded oral challenge (GOC)—amoxicillin 25 mg followed by 250 mg. Reactions were recorded, and participant/provider surveys were conducted.

Results

Of 284 participants, 72 (25.3%) were deemed high risk and were excluded. Of 206 low-risk participants, 102 (49.5%) underwent PST without reactions and 3 (3%) had mild reactions during the oral challenge. Of 104 (50.5%) participants in the GOC, 95 (91.3%) completed challenges without reaction, 4 (4.2%) had mild symptoms after 25 mg, and 4 (4.2%) after 250-mg doses. Overall, 195 participants (94.7%) successfully completed the study and 11 (5.3%) experienced mild symptoms. Of 14 providers, 12 (85.7%) completed surveys and 11 (93%) agreed on the safety/effectiveness of penicillin allergy assessment in STI clinics.

Conclusions

An easy-to-administer risk-assessment questionnaire can safely identify patients for penicillin allergy evaluation in STI clinics by PST or GOC, with GOC showing operational feasibility. Using this approach, 67% of participants with reported penicillin allergy could safely receive first-line treatments for gonorrhea or syphilis.

Clinical Trials Registration. Clinicaltrials.gov (NCT04620746).
Endovascular aortic arch repair under monitored anaesthesia care: maximizing microinvasiveness
Authors: D’Onofrio Augusto , Piazza Michele , Andreatta Giulio , Cao Irene , Lombardi Valentina , Pittarello Demetrio , Grego Franco , Antonello Michele , Gerosa Gino
Published: February 2024

Patients with aortic arch pathologies after surgery for type-A acute aortic dissection represent a challenging population since open surgery is associated with a non-negligible rate of mortality and complications. Microinvasive endovascular aortic arch repair Arch-Thoracic EndoVascular Aortic Repair (Ar-TEVAR) has shown promising results in high-risk patients. Ar-TEVAR is usually performed under general anaesthesia. We report the case of an 83-year-old man with a history of ascending aorta replacement for type-A acute aortic dissection who was referred for an anastomotic pseudoaneurysm. Ar-TEVAR using an off-the-shelf single-branch aortic arch stent graft was chosen. In order to further minimize procedural invasiveness, monitored anaesthesia care (local anaesthesia with sedation and analgesia) was performed since it provides less stress on the cardiovascular and respiratory systems and overall leads to a faster recovery especially in elderly patients.
Resilience of aerobic methanotrophs in soils; spotlight on the methane sink under agriculture
Authors: Lim Jiyeon , Wehmeyer Helena , Heffner Tanja , Aeppli Meret , Gu Wenyu , Kim Pil Joo , Horn Marcus A , Ho Adrian
Published: February 2024

Aerobic methanotrophs are a specialized microbial group, catalyzing the oxidation of methane. Disturbance-induced loss of methanotroph diversity/abundance, thus results in the loss of this biological methane sink. Here, we synthesized and conceptualized the resilience of the methanotrophs to sporadic, recurring, and compounded disturbances in soils. The methanotrophs showed remarkable resilience to sporadic disturbances, recovering in activity and population size. However, activity was severely compromised when disturbance persisted or reoccurred at increasing frequency, and was significantly impaired following change in land use. Next, we consolidated the impact of agricultural practices after land conversion on the soil methane sink. The effects of key interventions (tillage, organic matter input, and cover cropping) where much knowledge has been gathered were considered. Pairwise comparisons of these interventions to nontreated agricultural soils indicate that the agriculture-induced impact on the methane sink depends on the cropping system, which can be associated to the physiology of the methanotrophs. The impact of agriculture is more evident in upland soils, where the methanotrophs play a more prominent role than the methanogens in modulating overall methane flux. Although resilient to sporadic disturbances, the methanotrophs are vulnerable to compounded disturbances induced by anthropogenic activities, significantly affecting the methane sink function.
Unveiling the microbiome of hydroponically cultivated lettuce: impact of Phytophthora cryptogea infection on plant-associated microorganisms
Authors: Vlasselaer Liese , Crauwels Sam , Lievens Bart , De Coninck Barbara
Published: February 2024

Understanding the complex interactions between plants and their associated microorganisms is crucial for optimizing plant health and productivity. While microbiomes of soil-bound cultivated crops are extensively studied, microbiomes of hydroponically cultivated crops have received limited attention. To address this knowledge gap, we investigated the rhizosphere and root endosphere of hydroponically cultivated lettuce. Additionally, we sought to explore the potential impact of the oomycete pathogen Phytophthora cryptogea on these microbiomes. Root samples were collected from symptomatic and nonsymptomatic plants in three different greenhouses. Amplicon sequencing of the bacterial 16S rRNA gene revealed significant alterations in the bacterial community upon P. cryptogea infection, particularly in the rhizosphere. Permutational multivariate analysis of variance (perMANOVA) revealed significant differences in microbial communities between plants from the three greenhouses, and between symptomatic and nonsymptomatic plants. Further analysis uncovered differentially abundant zero-radius operational taxonomic units (zOTUs) between symptomatic and nonsymptomatic plants. Interestingly, members of Pseudomonas and Flavobacterium were positively associated with symptomatic plants. Overall, this study provides valuable insights into the microbiome of hydroponically cultivated plants and highlights the influence of pathogen invasion on plant-associated microbial communities. Further research is required to elucidate the potential role of Pseudomonas and Flavobacterium spp. in controlling P. cryptogea infections within hydroponically cultivated lettuce greenhouses.
The chromosome-scale genome and population genomics reveal the adaptative evolution of Populus pruinosa to desertification environment
Authors: Sun Jianhao , Xu Jindong , Qiu Chen , Zhai Juntuan , Zhang Shanhe , Zhang Xiao , Wu Zhihua , Li Zhijun
Published: February 2024

The Populus pruinosa is a relic plant that has managed to survive in extremely harsh desert environments. Owing to intensifying global warming and desertification, research into ecological adaptation and speciation of P. pruinosa has attracted considerable interest, but the lack of a chromosome-scale genome has limited adaptive evolution research. Here, a 521.09 Mb chromosome-level reference genome of P. pruinosa was reported. Genome evolution and comparative genomic analysis revealed that tandemly duplicated genes and expanded gene families in P. pruinosa contributed to adaptability to extreme desert environments (especially high salinity and drought). The long terminal repeat retrotransposons (LTR-RTs) inserted genes in the gene body region might drive the adaptive evolution of P. pruinosa and species differentiation in saline-alkali desert environments. We recovered genetic differentiation in the populations of the northern Tianshan Mountain and southern Tianshan Mountain through whole-genome resequencing of 156 P. pruinosa individuals from 25 populations in China. Further analyses revealed that precipitation drove the local adaptation of P. pruinosa populations via some genetic sites, such as MAG2-interacting protein 2 (MIP2) and SET domain protein 25 (SDG25). This study will provide broad implications for adaptative evolution and population studies by integrating internal genetic and external environmental factors in P. pruinosa.
Antiviral factors and their counteraction by HIV-1: many uncovered and more to be discovered
Authors: Kmiec Dorota , Kirchhoff Frank
Published: February 2024

Extensive studies on HIV-1 have led to the discovery of a variety of structurally and functionally diverse innate defense factors that target various steps of the retroviral replication cycle. Some of them, such as APOBEC3, tetherin, and SERINC5, are well established. Their importance is evident from the fact that HIV-1 uses its accessory proteins Vif, Vpu, and Nef to counteract them. However, the list of antiviral factors is constantly increasing, and accumulating evidence suggests that innate defense mechanisms, which restrict HIV-1 and/or are counteracted by viral proteins, remain to be discovered. These antiviral factors are relevant to diseases other than HIV/AIDS, since they are commonly active against various viral pathogens. In this review, we provide an overview of recently reported antiretroviral factors and viral countermeasures, present the evidence suggesting that more innate defense mechanisms remain to be discovered, and discuss why this is a challenging but rewarding task.
(010) Provider Habits on Screening Sexual Dysfunction in Pregnancy: A Novel Mixed Methods Study
Authors: Casinelli E , Walker K , Lynn M
Published: February 2024

Introduction

The prevalence of sexual dysfunction increases throughout pregnancy. The American College of Obstetricians and Gynecologists (ACOG) recommends screening for sexual dysfunction in pregnancy, however, there is little information on when or how this is occurring.

Objective

To evaluate provider opinions and screening habits regarding sexual dysfunction in pregnancy.

Methods

This is a mixed methods study conducted with an opinion/practice survey completed by 31 perinatal care providers in Illinois and a randomized, retrospective chart review of obstetric clinic visits of 113 patients at a tertiary medical center in the Chicago metro area.

Results

85% of providers believe that sexual dysfunction is either somewhat (n=17) or very important (n=9) as compared to other conditions in pregnancy. Approximately one third (n=11) of providers indicate that they regularly screen for sexual dysfunction in pregnancy. 19% of patients (n=21) charts contained evidence of screening for sexual dysfunction during the perinatal period. Less than half of those with evidence of screening were screened antepartum (n=8). No patients had evidence of screening in the third trimester. Of those patients denoted as screened, 76% (n=16) reported symptoms of sexual dysfunction.

Conclusions

The findings from the survey pilot study demonstrate that while most providers agree sexual dysfunction in pregnancy is somewhat to very important, there is significant variability in their approach to addressing it, with a majority not addressing it at all. Providers reported multiple barriers to screening including a lack of time and appropriate training. Minimal evidence of sexual dysfunction screening or education during prenatal care was seen on chart review. Given the known high prevalence of sexual dysfunction in the perinatal period, these findings elucidate a need for the development of uniform, screening and education standards for pregnancy.

Disclosure

No.
(049) Prevalence of Erectile Dysfunction in Men with Stress Urinary Incontinence After Radical Prostatectomy
Authors: Elshafei A , Ljubetic BM , Novaes LF , Benfante N , Cheung F , Sandhu J , Mulhall JP , Flores JM
Published: February 2024

Introduction

Stress urinary incontinence (SUI) and erectile dysfunction (ED) are significant complications that have a negative impact on patients' quality of life following radical prostatectomy (RP).

Objective

This study aimed to assess the prevalence of ED in men with SUI who underwent RP the first year after RP.

Methods

This study included men who underwent RP and followed up for 1 year post-surgery. Men who received androgen deprivation therapy (ADT) or radiation therapy before or after RP were excluded. We performed a descriptive assessment of demographics, comorbidities, erectile function (EF), laboratory, surgical pathology, and nerve-sparing status (NSS). Post-op SUI was described based on the number of pads used per day, categorized as 0 to 1 pad per day (continent or mild/social SUI), 2 pads per day (moderate SUI), and ≥ 3 pads per day (severe SUI) at 3, 6, and 12 months post-RP. ED was described based on IIEF score as normal EF normal (≥24), mild ED (18-23), moderate ED (11-17), and severe ED (≤10) at 3, 6, and 12 months post-RP. We reported the prevalence of ED among men with SUI during the first year after RP. We assessed if the severity of the SUI was a predictor of severe ED in a multivariable logistic regression model at 3, 6, and 12 months post-RP. Factors entered into the model included: patient age, number of comorbidities (≥ 3), NVB status (both resected), pre-RP EF, PDE5i exposure post-RP (yes), and severe SUI (≥ 3 pads per day).

Results

9953 men were included in this study, with a median age of 62 (56, 67). The median number of comorbidities was 1 (0, 2). 10% had diabetes, 27% obstructive sleep apnea, and 19% reported 3 or more comorbidities. Preoperative median PSA was 5.7 ng/ml, with a median Gleason grade of 2 (2, 3).73% had Bilateral NSS, 20% unilateral, and 7% had both sides resected. The prevalence of severe ED was higher among men with severe SUI compared to men with 0 to 1 pad per day at 3, 6, and 12 months post-RP. At 3 months, men with 0 to 1 pad per day reported 31% no/mild ED and 59% severe ED, vs. men with severe SUI described 18% no/mild ED and 75% severe ED (p-value <0.001). At 6 months, for men with continence/mild SUI, 35% described no/mild Ed and 51% severe ED vs. men with severe SUI who had 20% no/mild ED and 70% severe ED (p-value <0.001). And at 12 months, men with 0 to 1 pad per day reported 42% no/mild ED and 46% severe ED, vs. men with severe SUI described 22% no/mild ED and 70% severe ED (p-value <0.001). In the multivariable regression model, severe SUI significantly predicted severe ED at 3, 6, and 12 months (Table1).

Conclusions

Men experiencing severe SUI have a high prevalence of severe erectile dysfunction. Severe SUI significantly predicted severe ED during the first year following RP.

Disclosure

No.
(063) The Role of Leptin as a Testicular Immune Microenvironment Modulator and Leydig Stem Cell Function
Authors: Dullea A , Khodamoradi K , Seetharam D , Issa I , Ramasamy R , Arora H
Published: February 2024

Introduction

The testicular microenvironment, consisting of cells including Sertoli and peritubular cells, releases paracrine factors that may regulate testicular function. In previous research, Leptin was identified as a critical paracrine factor in the testicular microenvironment. Leptin is secreted by Sertoli and peritubular cells and binds to its receptor in Leydig cells. This interaction triggers the expression of the desert hedgehog signaling pathway, which is essential for Leydig stem cell differentiation into adult Leydig cells, which are capable of producing testosterone. However, our earlier study had a limitation: the human cell model used was derived from testes biopsies, lacking an intact immune microenvironment. This study investigates the effect of Leptin on a complete testicular immune microenvironment in a murine model.

Objective

To investigate the impact of Leptin on a complete testicular immune microenvironment.

Methods

We used 6-week-old C57BL6 mice, exposed to two different concentrations of Leptin, 10 and 100 mg/ml, for seven days. After the treatment period, the animals were humanely euthanized, and their blood and testes were collected. Blood samples underwent a complete blood count differential profile analysis using a Hemavet Mascot Multispecies Hematology System Counter 1500R. Testes samples were subjected to comprehensive immunophenotyping, allowing us to assess the impact of Leptin treatment on various immune cell types within the testes

Results

Leptin at a low dose (10 mg/ml) showed increased, but not significant, levels of serum testosterone (13.20 + 0.37 ng/dl), while LH and FSH levels significantly (p<0.05) increased. In contrast, animals receiving 100 mg/ml Leptin showed no significant changes in hormone levels. CBC profiling indicated that lymphocytes and platelets were significantly influenced, specifically with low doses of Leptin. Comprehensive immunophenotyping revealed a significant increase in CD4+ (helper T cells) and CD8+ (cytotoxic T lymphocytes) cell numbers in animals treated with low doses of Leptin, a pattern not observed with high doses.

Conclusions

This study uncovers previously unexplored aspects of how paracrine factors, released by Sertoli and peritubular myoid cells, can modulate the immune microenvironment within the testis, potentially impacting testosterone production. Future research will investigate the relationship between changes in immune cell types, increased T cell numbers, and their influence on Leydig stem cell differentiation into adult Leydig cells

Disclosure

No.
(071) Just Another Vaccine – VAERS Analysis Compares Genitourinary Symptoms of the COVID-19 Vaccine and Other Commonly Administered Vaccines
Authors: Lichtbroun B , Moore K , Rajagopalan A , Chua K , Velez-Leitner D
Published: February 2024

Introduction

There has been a concern in mainstream media about adverse effects of the COVID-19 vaccine including those on the genitourinary system.

Objective

Our objective was to evaluate the rate of patient-reported genitourinary symptoms after the COVID-19 vaccine. We hypothesized rates of genitourinary side effects was not different compared to other commonly used vaccines.

Methods

We queried the Vaccine Adverse Events Reporting System (VAERS) database for all genitourinary symptoms reported after receiving the COVID-19, influenza, shingles, and pneumonia vaccines. Symptoms were placed into one of five categories – lower urinary tract symptoms (LUTS), sexual side effects, infectious, hematuria, or other disorders of the penis/scrotum/testis. Rates of genitourinary symptoms were compared between the vaccines. Data collection occurred 7-8/2022.

Results

Out of 13,568,650 symptoms reported after the COVID-19 vaccine, 9,022 were genitourinary (0.066%). Genitourinary symptoms included LUTS (39.71%), infectious (32.38%), hematuria (17.42%), disorders of the penis/scrotum/testis (5.99%), and sexual side effects (4.50%). Rates of genitourinary symptoms after the COVID-19 vaccine was significantly lower than the influenza (0.128%) (Table 1) but higher than the shingles (0.030%) and pneumonia (0.037%) vaccines (Table 2). There was no significant differences in the penis/scrotum/testis symptoms category. Rates of sexual side effects were overall low after the COVID vaccine (0.0030%) and not significantly different to rates of sexual side effects after the influenza vaccine (0.0036%) but were higher than after the pneumonia and shingles vaccines.

Conclusions

Genitourinary symptoms from the COVID-19 vaccine are rare. The rate of side effects is lower than the influenza vaccine, and while sexual and overall side effects are higher than the pneumonia and shingles vaccines, these rates are overall very low and unlikely to be clinically significant.

Disclosure

No.